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Sample records for sintered iron ore

  1. Influencing factor of sinter body strength and its effects on iron ore sintering indexes

    NASA Astrophysics Data System (ADS)

    Zhang, Guo-liang; Wu, Sheng-li; Su, Bo; Que, Zhi-gang; Hou, Chao-gang; Jiang, Yao

    2015-06-01

    Sinter body strength, which reflects the strength of sinter, plays an important role in the improvement of sinter. In this study, the sinter body strengths of iron ores were measured using a microsintering method. The relationship between the chemical composition and sinter body strength was discussed. Moreover, sinter-pot tests were performed. The effects of sinter body strength on the sintering indexes were then elucidated, and the bottom limit of sinter body strength of blending ores was confirmed. In the results, the compressive strengths (CSs) of iron ores are observed to decrease with the increasing of the contents of loss on ignition (LOI), SiO2, and Al2O3; however, LOI of less than 3wt% does not substantially influence the CSs of fine ores. In the case of similar mineral composition, the porosity, in particular, the ratio between the number of large pores and the total number of pores, strongly influences the sinter body strength. With an increase of the blending-ore CSs used in sinter-pot tests, the yield, productivity, and tumbler strength increase, and the solid fuel consumption decreases. The CSs of the blending ores only slightly affect the sintering time. The CS bottom limit of the blending ores is 310 N. When the CSs of the blending ores increase by 10%, the yield, productivity, and tumbler index increase by 1.9%, 2.8%, and 2.0%, respectively, and the solid fuel consumption decreases by 1.9%.

  2. High-temperature performance prediction of iron ore fines and the ore-blending programming problem in sintering

    NASA Astrophysics Data System (ADS)

    Yan, Bing-ji; Zhang, Jian-liang; Guo, Hong-wei; Chen, Ling-kun; Li, Wei

    2014-08-01

    The high-temperature performance of iron ore fines is an important factor in optimizing ore blending in sintering. However, the application of linear regression analysis and the linear combination method in most other studies always leads to a large deviation from the desired results. In this study, the fuzzy membership functions of the assimilation ability temperature and the liquid fluidity were proposed based on the fuzzy mathematics theory to construct a model for predicting the high-temperature performance of mixed iron ore. Comparisons of the prediction model and experimental results were presented. The results illustrate that the prediction model is more accurate and effective than previously developed models. In addition, fuzzy constraints for the high-temperature performance of iron ore in this research make the results of ore blending more comparable. A solution for the quantitative calculation as well as the programming of fuzzy constraints is also introduced.

  3. Influence of process changes on PCDD/Fs produced in an iron ore sintering plant

    SciTech Connect

    Guerriero, E.; Bianchini, M.; Gigliucci, P.F.; Guarnieri, A.; Mosca, S.; Rossetti, G.; Varde, M.; Rotatori, M.

    2009-01-15

    This study investigated the influence of different charge typologies and additives on the PCDD/Fs amount produced and on the congener profiles in an iron ore sintering plant. Many tests were carried out combining different typologies of charge (iron materials) and solid fuel ('coke breeze' or 'anthracite') with or without the use of urea. The PCDD/Fs produced ranged from 1.2 to 22.7 {mu} g I-TEQ/ton of agglomerate, whereas the PCDD/Fs released to the ambient air ranged from 0.10 to 1.92 ng I-TEQ/Nm{sup 3} because of cleaning in an electrostatic precipitator (ESP) and a Wetfine scrubber (WS). A more homogeneous charge with a higher amount of fine particles charge appeared to produce a lower PCDD/Fs concentration due to a better combustion but this hypothesis needs further investigations on charges having different dimension particles. Only a synergitic action of urea and anthracite was able to reduce the high PCDD/Fs content due to the bad combustion of the more inhomogeneous charge with a lower amount of fine particles. The congener profile was a typical combustion process fingerprint because the PCDFs predominated, the highly chlorinated congeners (HeptaCDD and OctaCDD) prevailed in PCDDs, whereas in PCDFs the profile was more varied; 1,2,3,4,6,7,8-HeptaCDF was the main contributor to the total concentration while 2,3,4,7,8-PentaCDF was the main contributor to the I-TEQ concentration. Whereas all the parameters under scrutiny influenced strongly the amount of PCDD/Fs produced, they affected only slightly the fingerprint of PCDD/Fs. In all cases studied, the reduction obtained using urea, anthracite, or the more homogeneous charge with a higher amount of fine particles was slightly greater on the higher chlorinated congeners in respect to the lower ones.

  4. The Energetics of Hematite Dissolution in Iron Ore Melts for Assimilation in Commercial Sintering Processes: In Situ High Temperature Calorimetric Studies

    NASA Astrophysics Data System (ADS)

    Navrotsky, A. A.; Morcos, R.; Ellis, B.

    2006-12-01

    Melting and crystallization of iron ores in mining applications are determined by the thermodynamic properties of the crystals and liquids in equilibrium. Iron ores are widely used for sinter production in Japan, Korea Russia, and Australia. In these sinter production plants, multiple ores can be blended together. Sintering is the second stage of a two step process in which iron ores fines, together with coke and flux material are converted into porous blocks of sinter that are suitable for direct feed into the blast furnace. The chemical and physical changes that occur during sintering are formation of granules, melt formation, assimilation and lastly crystallization. The initial stage involves the formation of granules in which small and intermediate sized particles adhere to larger nuclei via water bridging between adjacent particles. The second stage is known as assimilation; which involves the reaction between melt and un-melted iron ore particles during the sintering step. These ores are typically multi-component systems with numerous phases whose variability complicates industrial processing applications. High temperature calorimetry using molten iron-calcium-silicate solvents has been used to better understand and improve the industrial processing of iron ores, and evaluate the dissolution properties of Fe2O3 in a series of iron-oxide based melts at 1626 K. In the SFCA (silico-ferrite of calcium and aluminium) oxide mixture, the heat of solution of Fe2O3 for the first set of experiments is 52.5 b 10 kJ/mol as Fe2O3 concentration is increased from 59 to 64 mol%. The heat of solution was found to be strongly endothermic and independent of the liquid composition.

  5. Polycyclic aromatic hydrocarbon emission profiles and removal efficiency by electrostatic precipitator and wetfine scrubber in an iron ore sintering plant

    SciTech Connect

    Ettore Guerriero; Antonina Lutri; Rosanna Mabilia; Maria Concetta Tomasi Sciano; Mauro Rotatori

    2008-11-15

    A monitoring campaign of polychlorinated dibenzo-p-dioxins and dibenzofurans, polyaromatic hydrocarbons (PAHs), and polychlorinated biphenyl was carried out in an Italian iron ore sintering plant by sampling the combustion gases at the electrostatic precipitator (ESP) outlet, at the Wetfine scrubber (WS) outlet, and by collecting the ESP dust. Few data are available on these micropollutants produced in iron ore sintering plants, particularly from Italian plants. This study investigates the PAH emission profiles and the removal efficiency of ESPs and WS. PAHs were determined at the stack, ESP outlet flue gases, and in ESP dust to characterize the emission profiles and the performance of the ESP and the WS for reducing PAH emission. The 11 PAHs monitored are listed in the Italian legislative decree 152/2006. The mean total PAH sum concentration in the stack flue gases is 3.96 {mu}g/N m{sup 3}, in ESP outlet flue gases is 9.73 {mu}g/N m{sup 3}, and in ESP dust is 0.53 {mu}g/g. Regarding the emission profiles, the most abundant compound is benzo(b)fluoranthene, which has a relative low BaP toxic equivalency factors (TEF) value, followed by dibenzo(a,l)pyrene, which has a very high BaP(TEF) value. The emission profiles in ESP dust and in the flue gases after the ESP show some changes, whereas the fingerprint in ESP and stack flue gases is very similar. The removal efficiency of the ESP and of WS on the total PAH concentration is 5.2 and 59.5%, respectively. 2 figs., 5 tabs.

  6. Mechanical properties of dust collected by dust separators in iron ore sinter plants.

    PubMed

    Lanzerstorfer, Christof

    2015-12-01

    The flow-related mechanical properties of dusts from the de-dusting systems of several sinter plants were investigated. The mass median diameters of the dusts were in the range from approximately 3 to 100?µm. Also, the bulk density of the dusts varied in a wide range (approximately 400 to 2300?kg/m(3)). A good correlation between the bulk density and the mass median diameter for most of the dusts was found. In contrast, the angles of repose did not vary very much, only for the coarsest dust a significantly lower value was measured. The angles of internal friction as well as the wall friction angles were lower for coarse dust and higher for fine dust. The shear tests showed that both angles depend considerably on the stress level. At low stress, the angles decreased significantly with increasing values of stress, whereas at higher stress, the dependence was small or even disappeared. The only exception to this behaviour was shown by the finest dust. The flowability decreased with the particle size. The flowability categories suggested by the three flowability indicators were passable only for the coarser dusts. For the finer dusts, the flowability was overestimated by all flowability indicators. PMID:26075927

  7. Silico-ferrite of Calcium and Aluminum (SFCA) Iron Ore Sinter Bonding Phases: New Insights into Their Formation During Heating and Cooling

    NASA Astrophysics Data System (ADS)

    Webster, Nathan A. S.; Pownceby, Mark I.; Madsen, Ian C.; Kimpton, Justin A.

    2012-12-01

    The formation of silico-ferrite of calcium and aluminum (SFCA) and SFCA-I iron ore sinter phases during heating and cooling of synthetic iron ore sinter mixtures in the range 298 K to 1623 K (25 °C to 1350 °C) and at oxygen partial pressure of 5 × 10-3 atm has been characterized using in situ synchrotron X-ray diffraction. SFCA and SFCA-I are the key bonding phases in iron ore sinter, and an improved understanding of their formation mechanisms may lead to improved efficiency of industrial sintering processes. During heating, SFCA-I formation at 1327 K to 1392 K (1054 °C to 1119 °C) (depending on composition) was associated with the reaction of Fe2O3, 2CaO·Fe2O3, and SiO2. SFCA formation (1380 K to 1437 K [1107 °C to 1164 °C]) was associated with the reaction of CaO·Fe2O3, SiO2, and a phase with average composition 49.60, 9.09, 0.14, 7.93, and 32.15 wt pct Fe, Ca, Si, Al, and O, respectively. Increasing Al2O3 concentration in the starting sinter mixture increased the temperature range over which SFCA-I was stable before the formation of SFCA, and it stabilized SFCA to a higher temperature before it melted to form a Fe3O4 + melt phase assemblage (1486 K to 1581 K [1213 °C to 1308 °C]). During cooling, the first phase to crystallize from the melt (1452 K to 1561 K [1179 °C to 1288 °C]) was an Fe-rich phase, similar in composition to SFCA-I, and it had an average composition 58.88, 6.89, 0.82, 3.00, and 31.68 wt pct Fe, Ca, Si, Al, and O, respectively. At lower temperatures (1418 K to 1543 K [1145 °C to 1270 °C]), this phase reacted with melt to form SFCA. Increasing Al2O3 increased the temperature at which crystallization of the Fe-rich phase occurred, increased the temperature at which crystallization of SFCA occurred, and suppressed the formation of Fe2O3 (1358 K to 1418 K [1085 °C to 1145 °C]) to lower temperatures.

  8. High-rate behaviour of iron ore pellet

    NASA Astrophysics Data System (ADS)

    Gustafsson, Gustaf; Häggblad, Hans-Åke; Jonsén, Pär; Nishida, Masahiro

    2015-09-01

    Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

  9. Microbial reduction of iron ore

    DOEpatents

    Hoffmann, Michael R. (Pasadena, CA); Arnold, Robert G. (Pasadena, CA); Stephanopoulos, Gregory (Pasadena, CA)

    1989-01-01

    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry.

  10. Microbial reduction of iron ore

    DOEpatents

    Hoffmann, M.R.; Arnold, R.G.; Stephanopoulos, G.

    1989-11-14

    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry. 11 figs.

  11. Pilot plant experience in electron-beam treatment of iron-ore sintering flue gas and its application to coal boiler flue gas cleanup

    NASA Astrophysics Data System (ADS)

    Kawamura, K.; Shui, V. H.

    The peresent development status of the electron-beam flue gas treatment process, which is a dry process capable of removing SOx and NOx simultaneously, is described. The most advanced demonstration of this process was accomplished with a pilot plant in Japan where the maximum gas flow rate of 10,000 Nm 3/h of an iron-ore sintering machine flue gas was successfully treated. The byproduct produced in this process is collected as a dry powder which is a mixture of ammonia sulfate and ammonium nitrate and is salable as a fertilizer or a fertilizer component. A preliminary economic projection showed that this process costs less than the lime scrubber which removes SOx but does not remove NOx. Tests using simulated coal combustion gases suggest that this process will be applicable to coal-fired boiler flue gas treatment as well. However, test on actual coal-fired flue gases are still required for commercial application decisions. A process development unit program consisting of the design, construction and testing of actual coal-fired power station flue gases is underway in the U.S.A. The design and engineering of the test plant is far advanced and the construction phase will be launched in the very near future.

  12. AERIAL VIEW OF SINTERING PLANT CONVEYORS, BLOWING ENGINE HOUSE, ORE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    AERIAL VIEW OF SINTERING PLANT CONVEYORS, BLOWING ENGINE HOUSE, ORE YARD, BLAST FURNACE 1 & 2 & SHARED CAST HOUSE, & CENTRAL STEAM PLANT (LEFT TO RIGHT). - Pittsburgh Steel Company, Monessen Works, Donner Avenue, Monessen, Westmoreland County, PA

  13. Iron ore: energy, labor, and capital changes with technology.

    PubMed

    Kakela, P J

    1978-12-15

    Resource gathering is depending on leaner crude ores. Iron ore mining typifies this trend. To make lean taconite iron ores useful required a technologic breakthrough-pelletization. The shift to iron ore pellets has the advantage that they require less energy and labor per ton of molten iron than high-grade naturally concentrated ores. Increased reliance on pellets causes a geographic shift of some jobs and environmental effects from blast furnaces to iron ore mines. PMID:17735387

  14. The sources of our iron ores. II

    USGS Publications Warehouse

    Burchard, E.F.

    1933-01-01

    In this instalment** the iron ore deposits of the Lake Superior States, which normally furnish about 80 per cent, of the annual output of the United States, are described together with historical notes on discovery and transportation of ore. Deposits in the Mississippi Valley and Western States are likewise outlined and the sources of imported ore are given. Reviewing the whole field, it is indicated that the great producing deposits of the Lake Superior and southern Appalachian regions are of hematite in basin areas of sedimentary rocks, that hydrated iron oxides and iron carbonates are generally found in undisturbed comparatively recent sediments, and that magnetite occurs in metamorphic and igneous rocks; also that numerical abundance of deposits is not a criterion as to their real importance as a source of supply. Statistics of production of iron ore and estimates of reserves of present grade conclude the paper.

  15. Development of carbon composite iron ore micropellets by using the microfines of iron ore and carbon-bearing materials in iron making

    NASA Astrophysics Data System (ADS)

    Pal, Jagannath; Ghorai, Satadal; Das, Avimanyu

    2015-02-01

    Iron ore microfines and concentrate have very limited uses in sintering processes. They are used in pelletization; however, this process is cost intensive. Furthermore, the microfines of non-coking coal and other carbon-bearing materials, e.g., blast-furnace flue dust (BFD) and coke fines, are not used extensively in the metallurgical industry because of operational difficulties and handling problems. In the present work, to utilize these microfines, coal composite iron oxide micropellets (2-6 mm in size) were produced through an innovative technique in which lime and molasses were used as binding materials in the micropellets. The micropellets were subsequently treated with CO2 or the industrial waste gas to induce the chemical bond formation. The results show that, at a very high carbon level of 22wt% (38wt% coal), the cold crushing strength and abrasion index of the micropellets are 2.5-3 kg/cm2 and 5wt%-9wt%, respectively; these values indicate that the pellets are suitable for cold handling. The developed micropellets have strong potential as a heat source in smelting reduction in iron making and sintering to reduce coke breeze. The micropellets produced with BFD and coke fines (8wt%-12wt%) were used in iron ore sintering and were observed to reduce the coke breeze consumption by 3%-4%. The quality of the produced sinter was at par with that of the conventional blast-furnace sinter.

  16. Processing of Goethitic Iron Ore Fines

    NASA Astrophysics Data System (ADS)

    Sharma, J.; Sharma, T.; Mandre, N. R.

    2015-10-01

    In the present investigation an attempt has been made to beneficiate goethitic iron ore containing 59.02 % Iron, 6.51 % Alumina, 4.79 % Silica, 0.089 % Phosphorus with 7.11 % loss on ignition. For this purpose, different beneficiation techniques such as gravity and magnetic separation processes have been employed. During the process two conceptual flow sheets were also developed for the beneficiation of goethite iron ore fines. In the prsent work it was possible to enhance grade of iron to 63.35, 63.18, and 65.35 % from Jigging, Multi Gravity Separation (MGS) and Wet High Intensity Magnetic Separator (WHIMS) respectively.

  17. Leaching of the residue from the dry off-gas de-dusting and desulfurization process of an iron ore sinter plant

    NASA Astrophysics Data System (ADS)

    Lanzerstorfer, Christof; Xu, Qi; Neuhold, Robert

    2015-02-01

    The residue from a second-stage dry sinter plant off-gas cleaning process contains both the fine dust from the sinter plant and the sorbent used. Recycling of the material that is usually handled by landfills to the sinter plant feed is not possible because of its chloride content. Leaching of the chlorides allow the recycling of remaining solids. The saline leachate produced contains some heavy metals and must be treated before it is discharged into the sea. In laboratory experiments, leaching tests with the subsequent treatment of the leachate were conducted. After the process was optimized, all heavy-metal concentrations were below the permissible values. The optimum treatment conditions for heavy-metal precipitation were observed to be the filtration of the suspended solids followed by the dosing of liquid with lime milk (pH 10) and the subsequent precipitation using sodium sulfide.

  18. Characterisation and Processing of Some Iron Ores of India

    NASA Astrophysics Data System (ADS)

    Krishna, S. J. G.; Patil, M. R.; Rudrappa, C.; Kumar, S. P.; Ravi, B. P.

    2013-10-01

    Lack of process characterization data of the ores based on the granulometry, texture, mineralogy, physical, chemical, properties, merits and limitations of process, market and local conditions may mislead the mineral processing entrepreneur. The proper implementation of process characterization and geotechnical map data will result in optimized sustainable utilization of resource by processing. A few case studies of process characterization of some Indian iron ores are dealt with. The tentative ascending order of process refractoriness of iron ores is massive hematite/magnetite < marine black iron oxide sands < laminated soft friable siliceous ore fines < massive banded magnetite quartzite < laminated soft friable clayey aluminous ore fines < massive banded hematite quartzite/jasper < massive clayey hydrated iron oxide ore < manganese bearing iron ores massive < Ti-V bearing magnetite magmatic ore < ferruginous cherty quartzite. Based on diagnostic process characterization, the ores have been classified and generic process have been adopted for some Indian iron ores.

  19. Direct Biohydrometallurgical Extraction of Iron from Ore

    SciTech Connect

    T.C. Eisele

    2005-10-01

    A completely novel approach to iron extraction was investigated, based on reductive leaching of iron by anaerobic bacteria. Microorganisms were collected from an anaerobic bog where natural seepage of dissolved iron was observed. This mixed culture was used to reduce insoluble iron in a magnetite ore to the soluble ferrous (Fe{sup +2}) state. While dissolution rates were slow, concentrations of dissolved iron as high as 3487 mg/l could be reached if sufficient time was allowed. A factorial study of the effects of trace nutrients and different forms of organic matter indicated that the best dissolution rates and highest dissolved iron concentrations were achieved using soluble carbohydrate (sucrose) as the bacterial food source, and that nutrients other than nitrogen, phosphorus, potassium, sodium, and acetate were not necessary. A key factor in reaching high levels of dissolved iron was maintaining a high level of carbon dioxide in solution, since the solubility of iron carbonates increases markedly as the quantity of dissolved carbon dioxide increases. Once the iron is dissolved, it has been demonstrated that the ferrous iron can then be electroplated from solution, provided that the concentration of iron is sufficiently high and the hydrogen ion concentration is sufficiently low. However, if the leaching solution is electrolyzed directly, organic matter precipitates at the cathode along with the metallic iron. To prevent this problem, the ferrous iron should be separated from the bulk solution in a more concentrated, purified form. One route to accomplishing this is to take advantage of the change in solubility of ferrous iron as a function of carbon dioxide concentration. By cycling the concentration of carbon dioxide in solution, it is possible to produce an iron-rich concentrate that should be suitable for electrolysis. This represents the first viable hydrometallurgical method for leaching iron directly from ore and producing metallic iron.

  20. Extracting phosphoric iron under laboratorial conditions smelting bog iron ores

    NASA Astrophysics Data System (ADS)

    Török, B.; Thiele, A.

    2013-12-01

    In recent years it has been indicated by archaeometric investigations that phosphoric-iron (P-iron, low carbon steel with 0,5-1,5wt% P), which is an unknown and unused kind of steel in the modern industry, was widely used in different parts of the world in medieval times. In this study we try to explore the role of phosphorus in the arhaeometallurgy of iron and answer some questions regarding the smelting bog iron ores with high P-content. XRF analyses were performed on bog iron ores collected in Somogy county. Smelting experiments were carried out on bog iron ores using a laboratory model built on the basis of previously conducted reconstructed smelting experiments in copies of excavated furnaces. The effect of technological parameters on P-content of the resulted iron bloom was studied. OM and SEM-EDS analyses were carried out on the extracted iron and slag samples. On the basis of the material analyses it can be stated that P-iron is usually extracted but the P-content is highly affected by technological parameters. Typical microstructures of P-iron and of slag could also be identified. It could also be established that arsenic usually solved in high content in iron as well.

  1. CONTEXT VIEW ALONG EXISTING PERIMETER TRACKS LOOKING OVER IRON ORE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONTEXT VIEW ALONG EXISTING PERIMETER TRACKS LOOKING OVER IRON ORE CARS TOWARDS WESTERN SIDE OF CLEVELAND BULK TERMINAL BUILDINGS AND A SELF-UNLOADING IRON ORE SHIP AT DOCK. LOOKING SOUTHWEST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  2. CONTEXT VIEW ALONG EXISTING PERIMETER TRACKS LOOKING OVER IRON ORE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONTEXT VIEW ALONG EXISTING PERIMETER TRACKS LOOKING OVER IRON ORE CARS TOWARDS CLEVELAND BULK TERMINAL BUILDINGS. LOOKING SOUTH. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  3. Selective autocatalytic reduction of NO from sintering flue gas by the hot sintered ore in the presence of NH3.

    PubMed

    Chen, Wangsheng; Luo, Jing; Qin, Linbo; Han, Jun

    2015-12-01

    In this paper, the selective autocatalytic reduction of NO by NH3 combined with multi-metal oxides in the hot sintered ore was studied, and the catalytic activity of the hot sintered ore was investigated as a function of temperature, NH3/NO ratio, O2 content, H2O and SO2. The experimental results indicated that the hot sintered ore, when combined with NH3, had a maximum denitration efficiency of 37.67% at 450 °C, 3000 h(-1) gas hourly space velocity (GHSV) and a NH3/NO ratio of 0.4/1. Additionally, it was found that O2 played an important role in removing NOx. However, high O2 content had a negative effect on NO reduction. H2O was found to promote the denitration efficiency in the absence of SO2, while SO2 inhibited the catalytic activity of the sintered ore. In the presence of H2O and SO2, the catalytic activity of the sintered ore was dramatically suppressed. PMID:26363262

  4. A control relevant dynamic model of grate sintering Frode Martinsen, Bjarne A. Foss and Tor Arne Johansen

    E-print Network

    Foss, Bjarne A.

    process of sintering prepares the iron ore to form suitable feed for the blast furnace. Granulated ore into a partially fused porous sinter cake suitable for feeding to the blast furnace. Sintering is a complex process

  5. 40 CFR 440.10 - Applicability; description of the iron ore subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...false Applicability; description of the iron ore subcategory. 440.10 Section...MINING AND DRESSING POINT SOURCE CATEGORY Iron Ore Subcategory § 440.10 Applicability; description of the iron ore subcategory. The provisions...

  6. 40 CFR 440.10 - Applicability; description of the iron ore subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...false Applicability; description of the iron ore subcategory. 440.10 Section...MINING AND DRESSING POINT SOURCE CATEGORY Iron Ore Subcategory § 440.10 Applicability; description of the iron ore subcategory. The provisions...

  7. 40 CFR 440.10 - Applicability; description of the iron ore subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...false Applicability; description of the iron ore subcategory. 440.10 Section...MINING AND DRESSING POINT SOURCE CATEGORY Iron Ore Subcategory § 440.10 Applicability; description of the iron ore subcategory. The provisions...

  8. 40 CFR 440.10 - Applicability; description of the iron ore subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...false Applicability; description of the iron ore subcategory. 440.10 Section...MINING AND DRESSING POINT SOURCE CATEGORY Iron Ore Subcategory § 440.10 Applicability; description of the iron ore subcategory. The provisions...

  9. 40 CFR 440.10 - Applicability; description of the iron ore subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...false Applicability; description of the iron ore subcategory. 440.10 Section...MINING AND DRESSING POINT SOURCE CATEGORY Iron Ore Subcategory § 440.10 Applicability; description of the iron ore subcategory. The provisions...

  10. 26 CFR 1.272-1 - Expenditures relating to disposal of coal or domestic iron ore.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Expenditures relating to disposal of coal or domestic iron ore. 1.272-1 ...Expenditures relating to disposal of coal or domestic iron ore. (a) Introduction...hereafter sometimes referred to as a “coal royalty contract” or “iron ore...

  11. 26 CFR 1.272-1 - Expenditures relating to disposal of coal or domestic iron ore.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Expenditures relating to disposal of coal or domestic iron ore. 1.272-1 ...Expenditures relating to disposal of coal or domestic iron ore. (a) Introduction...hereafter sometimes referred to as a “coal royalty contract” or “iron ore...

  12. Ceramic colorant from untreated iron ore residue.

    PubMed

    Pereira, Oscar Costa; Bernardin, Adriano Michael

    2012-09-30

    This work deals with the development of a ceramic colorant for glazes from an untreated iron ore residue. 6 mass% of the residue was added in suspensions (1.80 g/cm(3) density and 30s viscosity) of white, transparent and matte glazes, which were applied as thin layers (0.5mm) on engobeb and not fired ceramic tiles. The tiles were fired in laboratory roller kiln in a cycle of 35 min and maximum temperatures between 1050 and 1180°C. The residue and glazes were characterized by chemical (XRF) and thermal (DTA and optical dilatometry) analyses, and the glazed tiles by colorimetric and XRD analyses. The results showed that the colorant embedded in the transparent glaze results in a reddish glaze (like pine nut) suitable for the ceramic roof tile industry. For the matte and white glazes, the residue has changed the color of the tiles with temperature. PMID:22795839

  13. 40 CFR 440.10 - Applicability; description of the iron ore subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the type of ore or its mode of occurrence; (b) mills beneficiating iron ores by physical (magnetic and nonmagnetic) and/or chemical separation; and (c) mills beneficiating iron ores by magnetic and...

  14. 40 CFR 440.10 - Applicability; description of the iron ore subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the type of ore or its mode of occurrence; (b) mills beneficiating iron ores by physical (magnetic and nonmagnetic) and/or chemical separation; and (c) mills beneficiating iron ores by magnetic and...

  15. 40 CFR 440.10 - Applicability; description of the iron ore subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the type of ore or its mode of occurrence; (b) mills beneficiating iron ores by physical (magnetic and nonmagnetic) and/or chemical separation; and (c) mills beneficiating iron ores by magnetic and...

  16. Effect of Microwave Treatment Upon Processing Oolitic High Phosphorus Iron Ore for Phosphorus Removal

    NASA Astrophysics Data System (ADS)

    Tang, Hui-Qing; Liu, Wei-Di; Zhang, Huan-Yu; Guo, Zhan-Cheng

    2014-10-01

    Influence of microwave treatment on the previously proposed phosphorus removal process of oolitic high phosphorus iron ore (gaseous reduction followed by melting separation) has been studied. Microwave treatment was carried out using a high-temperature microwave reactor (Model: MS-WH). Untreated ore fines and microwaved ore fines were then characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and thermogravimetric analysis (TGA). Thereafter, experiments on the proposed phosphorus removal process were conducted to examine the effect of microwave treatment. Results show that microwave treatment could change the microstructure of the ore fines and has an intensification effect on its gaseous reduction by reducing gas internal resistance, increasing chemical reaction rate and postponing the occurrence of sintering. Results of gaseous reduction tests using tubular furnace indicate both microwave treatment and high reduction temperature high as 1273 K (1000 °C) are needed to totally break down the dense oolite and metallization rate of the ore fines treated using microwave power of 450 W could reach 90 pct under 1273 K (1000 °C) and for 2 hours. Results of melting separation tests of the reduced ore fines with a metallization rate of 90 pct show that, in addition to the melting conditions in our previous studies, introducing 3 pct Na2CO3 to the highly reduced ore fines is necessary, and metal recovery rate and phosphorus content of metal could reach 83 pct and 0.31 mass pct, respectively.

  17. Microstructure of bentonite in iron ore green pellets.

    PubMed

    Bhuiyan, Iftekhar U; Mouzon, Johanne; Schröppel, Birgit; Kaech, Andres; Dobryden, Illia; Forsmo, Seija P E; Hedlund, Jonas

    2014-02-01

    Sodium-activated calcium bentonite is used as a binder in iron ore pellets and is known to increase strength of both wet and dry iron ore green pellets. In this article, the microstructure of bentonite in magnetite pellets is revealed for the first time using scanning electron microscopy. The microstructure of bentonite in wet and dry iron ore pellets, as well as in distilled water, was imaged by various imaging techniques (e.g., imaging at low voltage with monochromatic and decelerated beam or low loss backscattered electrons) and cryogenic methods (i.e., high pressure freezing and plunge freezing in liquid ethane). In wet iron ore green pellets, clay tactoids (stacks of parallel primary clay platelets) were very well dispersed and formed a voluminous network occupying the space available between mineral particles. When the pellet was dried, bentonite was drawn to the contact points between the particles and formed solid bridges, which impart strength to the solid compact. PMID:24397939

  18. Settling characteristics of ultrafine iron ore slimes

    NASA Astrophysics Data System (ADS)

    Eswaraiah, Chinthapudi; Biswal, Surendra Kumar; Mishra, Barada Kanta

    2012-02-01

    The slurry settling characteristics are the most important to design a thickener in process industries. In this work, the iron ore slurry from the screw classifier overflow was used for the settling study. It was observed that the original slurry exhibited a low settling velocity and a turbid supernatant during the settling process. Commercial flocculating agents with anionic, cationic, and nonionic characters were used to improve the settling behavior of suspensions, which were added into the slurry at different ranges of slurry pH values, respectively. The settling results show that the use of flocculants increase the settling rate by several times. Compared with the cationic and nonionic flocculants, the anionic flocculant is more effective in enhancing the slurry settling rate. The small dose of the anionic flocculant is found to be more effective, but the other flocculants are less effective even at higher dosages. The simulation of an industrial thickener was carried out based on the laboratory settling data, and the appropriate design and selection parameters of the industrial thickener were estimated.

  19. Challenges facing the North American iron ore industry

    USGS Publications Warehouse

    Jorgenson, J.D.

    2005-01-01

    During the 20th century, the iron ore mining industries of Canada and the United States passed through several periods of transformation. The beginning of the 21st century has seen yet another period of transformation, with the economic failure of a number of steel companies, the acquisition of their facilities by more viable steelmakers, and the consolidation of control within the North American iron ore industry. Changes in Canadian and United States iron ore production and the market control structure involved are analysed. The consolidation of ownership, formation of foreign joint ventures within Nordi America, planned divestitures of upstream activities by steelmakers, and industry changes made to ensure availability of feedstocks will be reviewed. The ttaditional isolation of the Canadian and United States iron ore operations and their strong linkage to downstream steel production will be discussed in the context of a changing global economy. Management-labour conflicts that have taken place and agreements made during 2000 through 2004 will be discussed in the context of the economic environment leading up to these agreements. Cooperative agreements between competing Canadian and United States companies to resolve client needs in processing and blending will be examined. A joint industry-government project designed to use new technology to produce direct reduced iron nuggets of 96 - 98 per cent iron content using non-coking coals will also be assessed. Changes in iron ore transportation methods, ownership and infrastructure will be reviewed for both rail and inland waterway transport between Canadian and United States companies. A brief analysis of social and environmental issues relating to sustainable development of the Canadian-United States iron ore industry will be included.

  20. 20 CFR 404.1084 - Gain or loss from disposition of property; capital assets; timber, coal, and iron ore...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...property; capital assets; timber, coal, and iron ore; involuntary conversion. 404...property; capital assets; timber, coal, and iron ore; involuntary conversion. (a...or loss; (3) From the disposal of iron ore mined in the United States,...

  1. 20 CFR 404.1084 - Gain or loss from disposition of property; capital assets; timber, coal, and iron ore...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...property; capital assets; timber, coal, and iron ore; involuntary conversion. 404...property; capital assets; timber, coal, and iron ore; involuntary conversion. (a...or loss; (3) From the disposal of iron ore mined in the United States,...

  2. 20 CFR 404.1084 - Gain or loss from disposition of property; capital assets; timber, coal, and iron ore...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...property; capital assets; timber, coal, and iron ore; involuntary conversion. 404...property; capital assets; timber, coal, and iron ore; involuntary conversion. (a...or loss; (3) From the disposal of iron ore mined in the United States,...

  3. 20 CFR 404.1084 - Gain or loss from disposition of property; capital assets; timber, coal, and iron ore...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...property; capital assets; timber, coal, and iron ore; involuntary conversion. 404...property; capital assets; timber, coal, and iron ore; involuntary conversion. (a...or loss; (3) From the disposal of iron ore mined in the United States,...

  4. 20 CFR 404.1084 - Gain or loss from disposition of property; capital assets; timber, coal, and iron ore...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...property; capital assets; timber, coal, and iron ore; involuntary conversion. 404...property; capital assets; timber, coal, and iron ore; involuntary conversion. (a...or loss; (3) From the disposal of iron ore mined in the United States,...

  5. 26 CFR 1.272-1 - Expenditures relating to disposal of coal or domestic iron ore.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...relating to disposal of coal or domestic iron ore. 1.272-1 Section 1.272-1...relating to disposal of coal or domestic iron ore. (a) Introduction. Section...as a “coal royalty contract” or “iron ore royalty contract”) for the...

  6. 26 CFR 1.272-1 - Expenditures relating to disposal of coal or domestic iron ore.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...relating to disposal of coal or domestic iron ore. 1.272-1 Section 1.272-1...relating to disposal of coal or domestic iron ore. (a) Introduction. Section...as a “coal royalty contract” or “iron ore royalty contract”) for the...

  7. 26 CFR 1.272-1 - Expenditures relating to disposal of coal or domestic iron ore.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...relating to disposal of coal or domestic iron ore. 1.272-1 Section 1.272-1...relating to disposal of coal or domestic iron ore. (a) Introduction. Section...as a “coal royalty contract” or “iron ore royalty contract”) for the...

  8. Application of LANDSAT satellite imagery for iron ore prospecting in the western desert of Egypt

    NASA Technical Reports Server (NTRS)

    Elshazly, E. M.; Abdel-Hady, M. A.; Elghawaby, M. A.; Khawasik, S. M. (principal investigators)

    1977-01-01

    The author has identified the following significant results. The delineation of the geological units and geological structures through image interpretation, corroborated by field observations and structural analysis, led to the discovery of new iron ore deposits. A new locality for iron ore deposition, namely Gebel Qalamun, was discovered, as well as new occurrences within the already known iron ore region of Bahariya Oasis.

  9. Challenges facing the North American iron ore industry

    USGS Publications Warehouse

    Jorgenson, J.D.

    2006-01-01

    Summary: This report is derived from a presentation the author presented in late September at the Iron Ore 2005 Conference sponsored by The Australasian Institute of Mining and Metallurgy and held in Fremantle, Western Australia. Some slight revisions have been made for the new audience.

  10. Cancer of the lung in iron ore (haematite) miners

    PubMed Central

    Boyd, J. T.; Doll, R.; Faulds, J. S.; Leiper, J.

    1970-01-01

    Boyd, J. T., Doll, R., Faulds, J. S., and Leiper, J.(1970).Brit. J. industr. Med.,27, 97-105. Cancer of the lung in iron ore (haematite) miners. The mortality of Cumberland iron-ore miners has been studied by examining the death certificates of 5 811 men resident in two local authority areas (Ennerdale R.D. and Whitehaven M.B.) who died between 1948 and 1967. Comparison of the iron miners' experience with (1) that of other local men and (2) the relevant national experience has provided an assessment of the suspected occupational risk of lung cancer associated with haematite mining. During the 20-year period there were 42 deaths attributed to lung cancer among iron mine employees resident in the study area: 36 of these occurred in miners working underground, which was significantly greater than that expected from local non-mining (20·6 deaths) or national (21·5 deaths) experience. In contrast to these findings, there was no evidence of any excess mortality from lung cancer among surface workers and, for iron miners as a whole, mortality from other cancers was close to the national experience. A parallel analysis of mortality among coal miners showed a deficit of deaths from lung cancer in line with other studies. The patterns of other respiratory mortality in the two local mining groups were also in line with previous experience, and confirmed the existence of a substantial silicotic hazard associated with haematite mining in Cumberland. These findings strengthen previous necropsy evidence and indicate that West Cumberland iron-ore miners who work underground experience an occupational hazard of lung cancer. They suggest that the miners suffer a lung cancer mortality about 70% higher than `normal'. The risk may be due to radioactivity in the air of the mines (average radon concentration of 100 p Ci/litre) or to a carcinogenic effect of iron oxide. PMID:5448525

  11. China's emergence as the world's leading iron-ore-consuming country

    USGS Publications Warehouse

    Kirk, W.S.

    2004-01-01

    China has become the leading iron ore consuming nation, and, based on recent steel production capacity increases and plans for more, its consumption will almost certainly to continue to grow. China's iron ore industry, however, faces a number of problems. China's iron ore is low-grade, expensive to process, and its mines are being depleted. For many Chinese steelmakers, particularly in the coastal regions, the delivered cost of domestic iron ore, is more than the delivered cost of foreign ore. Thus China's iron ore imports are expected to increase. As China's growth continues, it will almost certainly surpass Japan to become the leading iron ore importing country as well. Without China's increasing appetite for iron ore, the world iron ore market would be flat or declining. China's recent imports largely offset the slump in demand in North America and Europe. China is regarded by the iron ore industry as the growth sector for the next decade. Although Chinese imports are expected to continue their rapid increase and imports in other Asian countries are expected to continue growing, there appears to be enough greenfield and expansion projects to meet future demand for iron ore worldwide. Present suppliers of iron ore, Australia, Brazil, India, and South Africa, will probably be the chief beneficiaries of China's increasing consumption of iron ore. How long China can continue its extraordinary growth is the primary issue for the future of the iron ore industry. Based on the number and size of planned blast furnaces it appears that China's growth could continue for several more years. ?? 2004 Taylor and Francis.

  12. Direct reduction of iron ore by biomass char

    NASA Astrophysics Data System (ADS)

    Zuo, Hai-bin; Hu, Zheng-wen; Zhang, Jian-liang; Li, Jing; Liu, Zheng-jian

    2013-06-01

    By using thermogravimetric analysis the process and mechanism of iron ore reduced by biomass char were investigated and compared with those reduced by coal and coke. It is found that biomass char has a higher reactivity. The increase of carbon-to-oxygen mole ratio (C/O) can lead to the enhancement of reaction rate and reduction fraction, but cannot change the temperature and trend of each reaction. The reaction temperature of hematite reduced by biomass char is at least 100 K lower than that reduced by coal and coke, the maximum reaction rate is 1.57 times as high as that of coal, and the final reaction fraction is much higher. Model calculation indicates that the use of burden composed of biomass char and iron ore for blast furnaces can probably decrease the temperature of the thermal reserve zone and reduce the CO equilibrium concentration.

  13. Experimental research on the characteristics of softening and melting of iron ores as significant factor of influence on gas permeability of blast furnace charge

    NASA Astrophysics Data System (ADS)

    Branescu, E.; Blajan, A. O.; Constantin, N.

    2015-06-01

    It is widely accepted as a cohesive zone is directly influenced by softening and melting properties of iron ores, preparations (crowded, pellets, which represents about 90%, of the loads with metal furnace intake), or uncooked (raw ores ranked). Important results can be obtained through the study of behavior of ferrous materials at temperatures above 1000 ° C. Starting from research methods presented in the literature, this paper presents itself in carrying out their own laboratory experiments, conducted with the aim of analysing the softening and melting properties of sinter iron cores.

  14. Synthesis of Fe-MCM-41 Using Iron Ore Tailings as the Silicon and Iron Source

    PubMed Central

    Li, Xin; Yu, Honghao; He, Yan; Xue, Xiangxin

    2012-01-01

    Highly ordered Fe-MCM-41 molecular sieve was successfully synthesized by using n-hexadecyl-trimethyl ammonium bromide (CTAB) as the template and the iron ore tailings (IOTs) as the silicon and iron source. X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), diffuse reflectance UV-visible spectroscopy, 29Si magic-angle spinning (MAS) nuclear magnetic resonance (NMR), and nitrogen adsorption/desorption were used to characterize the samples. The results showed that the mesoporous materials had highly ordered 2-dimensional hexagonal structure. The synthesized sample had high surface area, and part of iron atoms is retained in the framework with formation of tetrahedron after removal of the template by calcinations. The results obtained in the present work demonstrate the feasibility of employing iron ore tailings as a potential source of silicon and iron to produce Fe-MCM-41 mesoporous materials. PMID:22567574

  15. High-carbon fly-ash as a binder for iron ore pellets

    SciTech Connect

    Kawatra, S.K.; Eisele, T.C.; Ripke, S.J.; Ramirez, G.

    1999-09-01

    The goal of this project was to convert currently unusable fly-ashes into a material that can be used as a binder for iron ore. Such a binder would also be useful for other high-volume markets, including foundry sand mold binders. Previously, the investigators used fly-ash in combination with calcium hydroxide as an additive while calcium chloride was added as a hardening accelerator. However, the addition of chloride salts have a detrimental effect because chlorine causes corrosion in processing equipment. Therefore, other potential hardening accelerators were investigated during this project. During production, dried iron-ore pellets are required to have crushing strength of at least 22.2 newtons (5 pounds force) per 12.7 mm (1/2 inch) diameter pellet. The pellets are then sintered at temperatures up to 1300 C and must not exhibit a significant degree of spalling or cracking. Pellets will therefore be tested to determine whether acceptable dry crushing strengths can be achieved.

  16. Mineralogy and geochemistry of banded iron formation and iron ores from eastern India with implications on their genesis

    NASA Astrophysics Data System (ADS)

    Roy, Subrata; Venkatesh, A. S.

    2009-12-01

    The geological complexities of banded iron formation (BIF) and associated iron ores of Jilling-Langalata iron ore deposits, Singhbhum-North Orissa Craton, belonging to Iron Ore Group (IOG) eastern India have been studied in detail along with the geochemical evaluation of different iron ores. The geochemical and mineralogical characterization suggests that the massive, hard laminated, soft laminated ore and blue dust had a genetic lineage from BIFs aided with certain input from hydrothermal activity. The PAAS normalized REE pattern of Jilling BIF striking positive Eu anomaly, resembling those of modern hydrothermal solutions from mid-oceanic ridge (MOR). Major part of the iron could have been added to the bottom sea water by hydrothermal solutions derived from hydrothermally active anoxic marine environments. The ubiquitous presence of intercalated tuffaceous shales indicates the volcanic signature in BIF. Mineralogical studies reveal that magnetite was the principal iron oxide mineral, whose depositional history is preserved in BHJ, where it remains in the form of martite and the platy hematite is mainly the product of martite. The different types of iron ores are intricately related with the BHJ. Removal of silica from BIF and successive precipitation of iron by hydrothermal fluids of possible meteoric origin resulted in the formation of martite-goethite ore. The hard laminated ore has been formed in the second phase of supergene processes, where the deep burial upgrades the hydrous iron oxides to hematite. The massive ore is syngenetic in origin with BHJ. Soft laminated ores and biscuity ores were formed where further precipitation of iron was partial or absent.

  17. Synthesis process of forsterite refractory by iron ore tailings.

    PubMed

    Li, Jing; Wang, Qi; Liu, Jihui; Li, Peng

    2009-01-01

    With mineral resources becoming gradually more deficient, as well as the issue of mine tailings causing environmental pollution, more and more people have realized the great significance of tailings utilization. Iron ore tailings, as a kind of secondary resource, have been developed in recycling industries. The feasibility to produce forsterite refractory from high-silicon iron tailings and high-magnesium raw materials were discussed. Also, the synthesis reaction processes were studied from the results of the laboratory experiments. The experiments showed that the synthesis processes can be separated into three steps when using iron tailings to synthesize forsterite: (1) produce magnesium iron sosoloid (Mg1-XFeXO) and magnesium metasilicate (MgSiO3), (2) form the fayalite, and (3) create the forsterite. The synthetic productions are primarily forsterite, hortonolite, and small amounts of magnesium metasilicate (MgSiO3). The hortonolite is wrapped around the surface of the forsterite particles and formed the cementing phase. In addition, the method to produce forsterite refractory and lightweight forsterite refractory from iron tailings were offered. PMID:25084443

  18. Facies and sedimentation model of iron-ore sequence in Bakchar deposit

    NASA Astrophysics Data System (ADS)

    Rudmin, M.; Mazurov, A.; Ruban, A.

    2015-02-01

    This article describes the investigation in the behavior and structure features of the iron-ore sequence in Bakchar ore deposit. Five facies characterizing the typical sedimentation environments were identified based on the analysis of typomorphic attributes of ore-bearing and barren deposits. The facies where oolitic ores are localized have been determined. A conceptual sedimentation model of the Bakchar ore mineralization has been proposed. Two facies- littoral argillo-arenaceous ferriferous sediments and mobile shallow alluvium oolitics were proposed as prospecting indicators of oolite hydrogoethite ore deposits.

  19. 26 CFR 1.272-1 - Expenditures relating to disposal of coal or domestic iron ore.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 3 2012-04-01 2012-04-01 false Expenditures relating to disposal of coal or... Expenditures relating to disposal of coal or domestic iron ore. (a) Introduction. Section 272 provides special... sometimes referred to as a “coal royalty contract” or “iron ore royalty contract”) for the disposal of...

  20. 26 CFR 1.272-1 - Expenditures relating to disposal of coal or domestic iron ore.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 3 2010-04-01 2010-04-01 false Expenditures relating to disposal of coal or... relating to disposal of coal or domestic iron ore. (a) Introduction. Section 272 provides special treatment... sometimes referred to as a “coal royalty contract” or “iron ore royalty contract”) for the disposal of...

  1. Separation of P Phase and Fe Phase in High Phosphorus Oolitic Iron Ore by Ultrafine Grinding and Gaseous Reduction in a Rotary Furnace

    NASA Astrophysics Data System (ADS)

    Gao, Jintao; Guo, Lei; Guo, Zhancheng

    2015-10-01

    Due to the oolitic structure of the high phosphorus iron ore and the closely wrapping of apatite and hematite phases, an approach using jet mill was utilized to grind the ore to ultrafine 0.01 to 0.001 mm, which realizes the dissociation of apatite phase and hematite phase. Then in a laboratory scale rotary furnace, high phosphorus ores of different sizes were reduced by reducing gas at sub-melting point temperatures (973 to 1173 K [700 to 900 °C]). In the rotating inclined reactor, the ore particles reacted with the reducing gas coming from the opposite direction in a rolling and discrete state, which greatly improved the kinetic conditions. In this study, the reaction rate increases significantly with the decrease of particle size. For the ultrafine high phosphorus iron ores, the metallization ratio can reach 83.91 to 97.32 pct, but only 33.24 to 40.22 pct for powders with the size of 0.13 to 0.15 mm. The reduced particles maintained their original sizes, without the presence of sintering phenomenon or iron whisker. Hence, two kinds of products were easily obtained by magnetic separation: the iron product with 91.42 wt pct of Fe and 0.19 wt pct of P, and the gangue product with 13.77 wt pct of Fe and 2.32 wt pct of P.

  2. Distribution Behavior of Phosphorus and Metallization of Iron Oxide in Carbothermic Reduction of High-Phosphorus Iron Ore

    NASA Astrophysics Data System (ADS)

    Cha, Ji-Whoe; Kim, Dong-Yuk; Jung, Sung-Mo

    2015-10-01

    Distribution behavior of phosphorus and metallization of iron ore in the carbothermic reduction of high-phosphorus iron ore were investigated. Reduction degree of the iron oxide was evaluated by quadruple mass spectrometry connected to thermogravimetric analysis. The distribution of some elements including phosphorus was examined by electron probe micro-analyzer mapping analyses. The reduction behavior of high-phosphorus iron ore was evaluated as a function of reduction temperature, C/O molar ratio, and CaO addition. High reduction temperature accelerated the reduction of both iron oxide and hydroxylapatite, and high C/O molar ratio also promotes both of them. Those were contradictory to the targets of higher reduction degree of iron oxide and of lower one of hydroxylapatite. It was confirmed that appropriate amount of CaO addition could enhance the reduction of iron oxide, and regulate the reduction of hydroxylapatite.

  3. Non-coke smelting reduction of iron ores: Process modelling

    NASA Astrophysics Data System (ADS)

    Pichestapong, Pipat

    The scarcity of coking coals and the high cost entailed in minimizing the emissions from the coke-making process as well as the relative inflexibility of large production capacity of the conventional blast-furnace ironmaking are the main reasons for the development of non-coke smelting reduction processes with the economical and ecological compatibility. The main objectives of the alternative processes development are to use ordinary coals directly, extend the range of usable raw materials, and allow the operation at a small scale. While most of smelting reduction processes are still in various stages of development, only the COREX ironmaking has successfully reached the industrial application with its first 300000 tpa plant operated in Pretoria, South Africa. The COREX process is composed of two main reactors: the vertical shaft furnace for the gaseous reduction of iron ore to sponge iron, and the melter-gasifier for the gasification of coal and smelting of iron. The gasification process generates the reducing gas mixture (CO and Hsb2) for use in the reduction furnace and also produces heat for smelting of the direct reduced iron. In the present work, the operating data of the COREX process are studied and process material and energy balances are prepared. The coal consumption rate of the COREX process is found higher than the coke consumption rate of the conventional process; however, the total energy consumption for the COREX process compares well with that of the blast furnace. The COREX process also generates surplus gas of high heating value which is suitable for many applications. A reduction model employing the diffusion-limited mass-transfer coupled with virtual equilibrium at core-interface is developed to determine the reduction of iron oxide pellets. The rate of oxygen-transfer between the solid and gas phases is computed by combining the Stefan-Maxwell multi-component diffusion formalism with the iterative equilibrium constant method. The computed results agree well with the observed data and the model is extended to simulate the reduction profiles in the reduction shaft of the COREX process. It is seen that the reduction process is mainly influenced by the pore-size and pore-structure of the reduced product layers.

  4. Mineralogical and geochemical characteristics of the Noamundi-Koira basin iron ore deposits (India)

    NASA Astrophysics Data System (ADS)

    Mirza, Azimuddin; Alvi, Shabbar Habib; Ilbeyli, Nurdane

    2015-04-01

    India is one of the richest sources of iron ore deposits in the world; and one of them is located in the Noamundi-Koira basin, Singhbhum-Orissa craton. The geological comparative studies of banded iron formation (BIF) and associated iron ores of Noamundi-Koira iron ore deposits, belonging to the iron ore group in eastern India, focus on the study of mineralogy and major elemental compositions along with the geological evaluation of different iron ores. The basement of the Singhbhum-Orissa craton is metasedimentary rocks which can be traced in a broadly elliptical pattern of granitoids, surrounded by metasediments and metavolcanics of Greenstone Belt association. The Singhbhum granitoid is intrusive into these old rocks and to younger, mid Archaean metasediments, including iron formations, schists and metaquartzites and siliciclastics of the Precambrian Iron Ore Group (Saha et al., 1994; Sharma, 1994). The iron ore of Noamundi-Koira can be divided into seven categories (Van Schalkwyk and Beukes 1986). They are massive, hard laminated, soft laminated, martite-goethite, powdery blue dust and lateritic ore. Although it is more or less accepted that the parent rock of iron ore is banded hematite jasper (BHJ), the presence of disseminated martite in BHJ suggests that the magnetite of protore was converted to martite. In the study area, possible genesis of high-grade hematite ore could have occurred in two steps. In the first stage, shallow, meteoric fluids affect primary, unaltered BIF by simultaneously oxidizing magnetite to martite and replacing quartz with hydrous iron oxides. In the second stage of supergene processes, deep burial upgrades the hydrous iron oxides to microplaty hematite. Removal of silica from BIF and successive precipitation of iron resulted in the formation of martite- goethite ore. Soft laminated ores were formed where precipitation of iron was partial or absent. The leached out space remains with time and the interstitial space is generally filled with kaolinite and gibbsite, which make it low grade. Massive iron ores are devoid of any lamination and usually associated with BHJ and lower shale. The thickness of the massive ore layer varies with the location. The massive iron ore grades in to well-developed bedded BHJ in depth. Blue dust occurs in association with BHJ as pockets and layers. Although blue dust and friable ore are both powdery ores, and subjected to variable degree of deformation, leading to the formation of folding, faulting and joints of complex nature produce favourable channels. Percolating water play an important role in the formation of blue dust and the subterranean solution offers the necessary acidic environment for leaching of quartz from the BHJ. The dissolution of silica and other alkalis are responsible for the formation of blue dust. The friable and powdery ore on the other hand are formed by soft laminated ore. As it is formed from the soft laminated ore, its alumina content remains high similar to soft laminated ore compaired to blue dust. Mineralogy study suggests that magnetite was the principal iron oxide mineral, now a relict phase whose depositional history is preserved in BHJ, where it remains in the form of martite. The platy hematite is mainly the product of martite. The different types of iron ores are intricately related with the BHJ. Hard laminated ores, martite-goethite ore and soft laminated ore are resultant of desilicification process through the action of hydrothermal fluids. Geochemistry of banded iron-formations of the Noamundi-Koira iron ore deposits shows that they are detritus-free chemical precipitates. The mineralogical and geochemical data suggest that the hard laminated, massive, soft laminated ores and blue dust had a genetic lineage from BIF's aided with certain input from hydrothermal activity. The comparative study of major elemental composition of the basin samples and while plotting a binary diagram, it shows a relation between major oxides against iron oxides, in which iron oxides is taken as a reference oxide (Mirza, 2011). On the other hand

  5. Iron ore and coal: pricing and volume up for these key export commodities

    SciTech Connect

    2006-01-15

    Australia's huge coal and iron ore industries are booming. Up until now, the majors have benefited handsomely, but smaller players are beginning to muscle in. The article discusses development in both industries. 1 fig., 4 photos.

  6. Rare view into iron-ore melting furnace with inflow pellets during inspection cycle (Corus).

    E-print Network

    Al Hanbali, Ahmad

    · Rare view into iron-ore melting furnace with inflow pellets during inspection cycle (Corus). #12, University of Twente, The Netherlands Institute of Mechanics, Processes and Control, Twente GFD Program Woods

  7. Rare view into iron-ore melting furnace with inflow pellets during inspection cycle (Corus).

    E-print Network

    Al Hanbali, Ahmad

    · Rare view into iron-ore melting furnace with inflow pellets during inspection cycle (Corus). #12 of Mechanics, Processes and Control, Twente GFD Program Woods Hole Oceanographic Institution #12;Granular flows

  8. Rare view into iron-ore melting furnace with inflow pellets during inspection cycle (Corus).

    E-print Network

    Al Hanbali, Ahmad

    · Rare view into iron-ore melting furnace with inflow pellets during inspection cycle (Corus). #12 of Mechanics, Processes and Control, Twente GFD Program Woods Hole Oceanographic Institution #12;Rapid granular

  9. Investigation of Direct Reduction Mechanism of Attepe Iron Ore by Hydrogen in a Fluidized Bed

    NASA Astrophysics Data System (ADS)

    D?lmaç, Nesibe; Yörük, Sedat; Gülabo?lu, ?ahin M.

    2015-10-01

    In this study, the kinetics of reduction of Attepe iron ore by H2 in a batch fluidized bed is analyzed at temperatures of 873 K, 973 K, and 1073 K (600 °C, 700 °C, and 800 °C). It is determined that the reduction route includes two consecutive regions controlled by distinct steps. The first region which takes place at low reduction levels is determined to be controlled by nucleation of wustite, while the following is determined to be controlled by gas/solid reaction occurring at metallic iron/wustite interface. An " ad-hoc" model is used to represent the reduction of Attepe iron ore to metallic iron with good accuracy.

  10. Production of lightweight ceramisite from iron ore tailings and its performance investigation in a biological aerated filter (BAF) reactor.

    PubMed

    Liu, Yangsheng; Du, Fang; Yuan, Li; Zeng, Hui; Kong, Sifang

    2010-06-15

    The few reuse and large stockpile of iron ore tailings (IOT) led to a series of social and environmental problems. This study investigated the possibility of using the IOT as one of starting materials to prepare lightweight ceramisite (LWC) by a high temperature sintering process. Coal fly ash (CFA) and municipal sewage sludge (SS) were introduced as additives. The LWC was used to serve as a biomedium in a biological aerated filter (BAF) reactor for municipal wastewater treatment, and its purification performance was examined. The effects of sintering parameters on physical properties of the LWC, and leaching concentrations of heavy metals from the LWC were also determined. The microstructure and the phase composition of the LWC were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Results revealed that: (1) IOT could be used to produce the LWC under the optimal sintering parameters; (2) the leaching concentrations of heavy metals from the LWC were well below their respective regulatory levels in the China Environmental Quality Standards for Surface Water (CEQS); and (3) the BAF reactor with the LWC serving as the biomedium achieved high removal efficiencies for COD(Cr) (>92%), NH(4)(+)-N (>62%) and total phosphate (T-P) (>63%). Therefore, the LWC produced from the IOT was suitable to serve as the biomedium in the municipal wastewater treatment. PMID:20227178

  11. Structural controls on the formation and transposition of the Malmberget apatite iron ore deposit, northern Sweden

    NASA Astrophysics Data System (ADS)

    Bauer, Tobias; Sarlus, Zimer; Andersson, Joel; Kearney, Thomas

    2015-04-01

    The Malmberget mine is the World's second largest underground iron ore operation. It is composed of approximately 20 apatite iron ore bodies, whereas 13 ore bodies with 5-245 Mt each are presently mined. The massive magnetite ore is hosted within volcanic and volcaniclastic rocks. Host rocks within the entire area were subject to intense hydrothermal alteration. The ore reserves at beginning of 2012 totalled 290 Mt at 44 percent iron. Together with Kiruna and Svappavaara these three deposits stands for more than 90 percent of the iron ore production in Europe. An on-going collaborative research project aims at unravelling the structural geometries, relationships and control on ore formation and ore body transposition at different scales in the Gällivare district in general and in the Malmberget mine in particular. Recent results show the three-dimensional crustal architecture of the Malmberget deposit which has undergone at least two separate deformation events. The first deformation event (D1) resulted in the formation of a strong and penetrative cleavage (S1) forming a varyingly intense banding within the volcanic rocks. The D1-event coincides with the amphibolite facies peak metamorphism in the area. Distinct, biotite-rich D1 shear zones are spatially related to the majority of the S1-parallel massive magnetite bodies. These D1 shear zones seem to be responsible for a strong strain partitioning during D1. A second compressional event (D2) resulted in open to close folding of the S1 fabric, the D1 shear zones and the related ore bodies. The result is an asymmetric F2-synform with moderately south-west-plunging fold axis. Furthermore, distinct D2 high strain zones are responsible for local transposition of S1 fabrics, tight to isoclinal folding and channeling or re-mobilization of hydrothermal alteration minerals. Both deformation events are accompanied by syn- and late-tectonic granitic intrusions forming both foliated and unfoliated and commonly boudinaged granitic sheets and dikes. Strong hydrothermal alteration occurred during several phases and is spatially and temporally related to D1 and D2 structures. Based on the structural observations a robust three-dimensional framework model is currently constructed using MOVE by Midland Valley Exploration. The resulting 3D-model visualizes the F2 folding pattern, the spatial distribution of D1 and D2 high strain zones and the structural controls on both primary and remobilized ore minerals. This framework model can act as a base for further modelling actions as well as for production and near mine exploration purposes.

  12. 26 CFR 1.631-3 - Gain or loss upon the disposal of coal or domestic iron ore with a retained economic interest.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...loss upon the disposal of coal or domestic iron ore with a retained economic interest...loss upon the disposal of coal or domestic iron ore with a retained economic interest...disposes of coal (including lignite), or iron ore mined in the United States,...

  13. 26 CFR 1.631-3 - Gain or loss upon the disposal of coal or domestic iron ore with a retained economic interest.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...loss upon the disposal of coal or domestic iron ore with a retained economic interest...loss upon the disposal of coal or domestic iron ore with a retained economic interest...disposes of coal (including lignite), or iron ore mined in the United States,...

  14. 26 CFR 1.631-3 - Gain or loss upon the disposal of coal or domestic iron ore with a retained economic interest.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...loss upon the disposal of coal or domestic iron ore with a retained economic interest...loss upon the disposal of coal or domestic iron ore with a retained economic interest...disposes of coal (including lignite), or iron ore mined in the United States,...

  15. Method for the production of mineral wool and iron from serpentine ore

    DOEpatents

    O'Connor, William K. (Albany, OR); Rush, Gilbert E. (Scio, OR); Soltau, Glen F. (Lebanon, OR)

    2011-10-11

    Magnesium silicate mineral wools having a relatively high liquidus temperature of at least about 1400.degree. C. and to methods for the production thereof are provided. The methods of the present invention comprise melting a magnesium silicate feedstock (e.g., comprising a serpentine or olivine ore) having a liquidus temperature of at least about 1400.degree. C. to form a molten magnesium silicate, and subsequently fiberizing the molten magnesium silicate to produce a magnesium silicate mineral wool. In one embodiment, the magnesium silicate feedstock contains iron oxide (e.g., up to about 12% by weight). Preferably, the melting is performed in the presence of a reducing agent to produce an iron alloy, which can be separated from the molten ore. Useful magnesium silicate feedstocks include, without limitation, serpentine and olivine ores. Optionally, silicon dioxide can be added to the feedstock to lower the liquidus temperature thereof.

  16. XPS and FTIR spectroscopic study on microwave treated high phosphorus iron ore

    NASA Astrophysics Data System (ADS)

    Omran, Mamdouh; Fabritius, Timo; Elmahdy, Ahmed M.; Abdel-Khalek, Nagui A.; El-Aref, Mortada; Elmanawi, Abd El-Hamid

    2015-08-01

    A growing interest in microwave heating has emerged recently. Several potential microwave applications regarding minerals' processing have been investigated. This paper investigates the effect of microwave radiation on Egyptian high phosphorus iron ore. Three different iron ore samples have varying Fe2O3 and P2O5 contents and mineralogical textures were studied. A comparative study has been carried out between untreated and microwave treated iron ore. XRD and FTIR analyses showed that after microwave radiation the crystallinity of iron bearing minerals (hematite) increased, while the functional chemical groups of phosphorus bearing minerals (fluorapatite) and other gangues dissociated. High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). This means that after microwave radiation iron oxide (hematite, Fe3+) transformed into more magnetic phase. The results indicated that microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases.

  17. Optimization model coupling both chemical compositions and high-temperature characteristics of sintering materials for sintering burden

    NASA Astrophysics Data System (ADS)

    Li, Ke-jiang; Zhang, Jian-liang; Liu, Zheng-jian; Su, Bu-xin; Kong, Ling-tan; Yang, Tian-jun

    2014-03-01

    We developed a mathematical optimization model coupling chemical compositions and high-temperature characteristics of sintering materials, targeting the best quality and lowest cost. The simplex algorithm was adopted to solve this model. Four kinds of imported iron ores, two kinds of Chinese iron ore concentrates, and two kinds of fluxes were selected to verify both the model and the algorithm. The results confirmed the possibility of considering both chemical compositions and high-temperature characteristics of iron ores in the optimization model. This model provides a technical roadmap to obtain a precise mathematical correlation between the lowest cost and the grade of iron in sinters based on the condition of given raw materials, which can provide a reference to adjust the grade of iron in the sintering process for enterprise.

  18. Environmental impacts of iron ore tailings—The case of Tolo Harbour, Hong Kong

    NASA Astrophysics Data System (ADS)

    Wong, M. H.

    1981-03-01

    Disposal of iron ore tailings along the shore of Tolo Harbour, Hong Kong has altered the adjacent environment. Due to the ever-expanding population, the vast development of various industries, and the lack of sanitary control, the existing pollution problem of Tolo Harbour is serious. The iron ore tailings consist of a moderate amount of various heavy metals, e.g., copper, iron, manganese, lead, zinc, and a lower level of macronutrients. A few living organisms have been found colonizing this manmade habitat. Higher metal contents were also found in the tissue of Paphia sp. (clam); Scopimera intermedia (crab); Chaetomorpha brychagona (green alga); Enteromorpha crinita (green alga); and Neyraudia reynaudiana (grass). The area can be reclaimed by surface amelioration using inert materials, soils, or organic substrates, and by direct seeding, using nontolerant and tolerant plant materials. Reclamation of the tailings would improve the amenity of the adjacent environment and also mitigate pollution escaping to the sea.

  19. Utilization of Coke Oven Gas and Converter Gas in the Direct Reduction of Lump Iron Ore

    NASA Astrophysics Data System (ADS)

    Mousa, Elsayed Abdelhady; Babich, Alexander; Senk, Dieter

    2014-04-01

    The application of off-gases from the integrated steel plant for the direct reduction of lump iron ore could decrease not only the total production cost but also the energy consumption and CO2 emissions. The current study investigates the efficiency of reformed coke oven gas (RCOG), original coke oven gas (OCOG), and coke oven gas/basic oxygen furnace gas mixtures (RCOG/BOFG and OCOG/BOFG) in the direct reduction of lump iron ore. The results were compared to that of reformed natural gas (RNG), which is already applied in the commercial direct reduction processes. The reduction of lump ore was carried out at temperatures in the range of 1073 K to 1323 K (800 °C to 1050 °C) to simulate the reduction zone in direct reduction processes. Reflected light microscopy, scanning electron microscopy, and X-ray diffraction analysis were used to characterize the microstructure and the developed phases in the original and reduced lump iron ore. The rate-controlling mechanism of the reduced lump ore was predicted from the calculation of apparent activation energy and the examination of microstructure. At 1073 K to 1323 K (800 °C to 1050 °C), the reduction rate of lump ore was the highest in RCOG followed by OCOG. The reduction rate was found to decrease in the order RCOG > OCOG > RNG > OCOG-BOF > RCOG-BOFG at temperatures 1173 K to 1323 K (900 °C to 1050 °C). The developed fayalite (Fe2SiO4), which resulted from the reaction between wüstite and silica, had a significant effect on the reduction process. The reduction rate was increased as H2 content in the applied gas mixtures increased. The rate-determining step was mainly interfacial chemical reaction with limitation by gaseous diffusion at both initial (20 pct reduction) and moderate (60 pct reduction) stages of reduction. The solid-state diffusion mechanism affected the reduction rate only at moderate stages of reduction.

  20. Getting rid of the unwanted: highlights of developments and challenges of biobeneficiation of iron ore minerals-a review.

    PubMed

    Adeleke, Rasheed A

    2014-12-01

    The quest for quality mineral resources has led to the development of many technologies that can be used to refine minerals. Biohydrometallurgy is becoming an increasingly acceptable technology worldwide because it is cheap and environmentally friendly. This technology has been successfully developed for some sulphidic minerals such as gold and copper. In spite of wide acceptability of this technology, there are limitations to its applications especially in the treatment of non-sulphidic minerals such as iron ore minerals. High levels of elements such as potassium (K) and phosphorus (P) in iron ore minerals are known to reduce the quality and price of these minerals. Hydrometallurgical methods that are non-biological involving the use of chemicals are usually used to deal with this problem. However, recent advances in mining technologies favour green technologies, known as biohydrometallurgy, with minimal impact on the environment. This technology can be divided into two, namely bioleaching and biobeneficiation. This review focuses on Biobeneficiation of iron ore minerals. Biobeneficiation of iron ore is very challenging due to the low price and chemical constitution of the ore. There are substantial interests in the exploration of this technology for improving the quality of iron ore minerals. In this review, current developments in the biobeneficiation of iron ore minerals are considered, and potential solutions to challenges faced in the wider adoption of this technology are proposed. PMID:25293513

  1. Closed system Fischer-Tropsch synthesis over meteoritic iron, iron ore and nickel-iron alloy. [deuterium-carbon monoxide reaction catalysis

    NASA Technical Reports Server (NTRS)

    Nooner, D. W.; Gibert, J. M.; Gelpi, E.; Oro, J.

    1976-01-01

    Experiments were performed in which meteoritic iron, iron ore and nickel-iron alloy were used to catalyze (in Fischer-Tropsch synthesis) the reaction of deuterium and carbon monoxide in a closed vessel. Normal alkanes and alkenes and their monomethyl substituted isomers and aromatic hydrocarbons were synthesized. Iron oxide and oxidized-reduced Canyon Diablo used as Fischer-Tropsch catalysts were found to produce aromatic hydrocarbons in distributions having many of the features of those observed in carbonaceous chondrites, but only at temperatures and reaction times well above 300 C and 6-8 h.

  2. Effects of sintering temperatures on microstructure and wear resistance of iron-silica composite

    NASA Astrophysics Data System (ADS)

    Amir, Adibah; Mamat, Othman

    2015-07-01

    Ceramic particle reinforced into metal base matrix composite has been reported to produce higher strength and wear resistance than its alloys because the ceramic phases can strongly resist abrasion. In this study the iron matrix was reinforced with two compositions of 20 and 25 wt. % fine silica particles. The compacts were produced by using powder metallurgy fabrication technique and sintered at three sintering temperatures: 1000, 1100 and 1200°C. Effects of various sintering temperatures on microstructures and the composite's wear resistance were evaluated via optical and SEM microscopy. Both compositions were also subjected to ball-on-disk wear test. The results showed the reinforcement weight fraction of 20 wt.% of silica and sintering temperature at 1100°C exhibited better result, in all aspects. It possessed higher mechanical properties, it's microstructure revealed most intact reinforcing region and it displayed higher wear resistance during wear test.

  3. Iron and manganese removal by using manganese ore constructed wetlands in the reclamation of steel wastewater.

    PubMed

    Xu, Jing-Cheng; Chen, Gu; Huang, Xiang-Feng; Li, Guang-Ming; Liu, Jia; Yang, Na; Gao, Sai-Nan

    2009-09-30

    To reclaim treated steel wastewater as cooling water, manganese ore constructed wetland was proposed in this study for the removal of iron and manganese. In lab-scale wetlands, the performance of manganese ore wetland was found to be more stable and excellent than that of conventional gravel constructed wetland. The iron and manganese concentration in the former was below 0.05 mg/L at hydraulic retention time of 2-5 days when their influent concentrations were in the range of 0.16-2.24 mg/L and 0.11-2.23 mg/L, respectively. Moreover, its removals for COD, turbidity, ammonia nitrogen and total phosphorus were 55%, 90%, 67% and 93%, respectively, superior to the corresponding removals in the gravel wetland (31%, 86%, 58% and 78%, respectively). The good performance of manganese ore was ascribed to the enhanced biological manganese removal with the aid of manganese oxide surface and the smaller size of the medium. The presence of biological manganese oxidation was proven by the facts of good manganese removal in wetlands at chemical unfavorable conditions (such as ORP and pH) and the isolation of manganese oxidizing strains from the wetlands. Similar iron and manganese removal was later observed in a pilot-scale gravel-manganese-ore constructed wetland, even though the manganese ore portion in total volume was reduced from 100% (in the lab-scale) to only 4% (in the pilot-scale) for the sake of cost-saving. The quality of the polished wastewater not only satisfied the requirement for cooling water but also suitable as make-up water for other purposes. PMID:19443107

  4. Laser sintering of separated and uniformly distributed multiwall carbon nanotubes integrated iron nanocomposites

    NASA Astrophysics Data System (ADS)

    Lin, Dong; Richard Liu, C.; Cheng, Gary J.

    2014-03-01

    Uniform distribution of carbon nanotubes (CNTs) in metal matrix during additive manufacturing of nanocomposites is always a challenge since the CNTs tend to aggregate in the molten pool. In this study, Multiwall carbon nanotubes (MWNTs) were separated and distributed uniformly into iron matrix by laser sintering process. MWNTs and iron powders were mixed together by magnetic stir, coated on steel 4140 surface, followed by laser sintering. Due to the fast heating and cooling rate, the CNTs are evenly distributed in the metal matrix. The temperature field was calculated by multiphysics simulation considering size effects, including size dependent melting temperature, thermal conductivity, and heat capacity. The SEM, TEM, and XRD were used to understand the laser sintering of CNT integrated nanocomposites. The results proved the feasibility of this technique to synthesize MWNTS integrated metal matrix nanocomposites.

  5. Studies on the reduction kinetics of hematite iron ore pellets with noncoking coals for sponge iron plants

    SciTech Connect

    Kumar, M.; Mohapatra, P.; Patel, S.K.

    2009-07-01

    In the present investigation, fired pellets were made by mixing hematite iron ore fines of -100, -16+18, and -8+10 mesh size in different ratios and studies on their reduction kinetics in Lakhanpur, Orient OC-2 and Belpahar coals were carried out at temperatures ranging from 850{sup o}C to 1000{sup o}C with a view toward promoting the massive utilization of fines in ironmaking. The rate of reduction in all the fired iron ore pellets increased markedly with an increase in temperature up to 1000{sup o}C, and it was more intense in the first 30min. The values of activation energy, calculated from integral and differential approaches, for the reduction of fired pellets (prepared from iron ore fines of -100 mesh size) in coals were found to be in the range 131-148 and 130-181 kJ mol{sup -1} (for =0.2 to 0.8), indicating the process is controlled by a carbon gasification reaction. The addition of selected larger size particles in the matrix of -100 mesh size fines up to the extent studied decreased the activation energy and slightly increased the reduction rates of resultant fired pellets. In comparison to coal, the reduction of fired pellets in char was characterized by significantly lower reduction rates and higher activation energy.

  6. POLLUTION EFFECTS OF ABNORMAL OPERATIONS IN IRON AND STEEL MAKING. VOLUME II. SINTERING, MANUAL OF PRACTICE

    EPA Science Inventory

    The report is one in a six-volume series considering abnormal operating conditions (AOCs) in the primary section (sintering, blast furnace ironmaking, open hearth, electric furnace, and basic oxygen steelmaking) of an integrated iron and steel plant. Pollution standards, generall...

  7. Grinding Wear Behaviour of Stepped Austempered Ductile Iron as Media Material During Comminution of Iron Ore in Ball Mills

    NASA Astrophysics Data System (ADS)

    Raghavendra, H.; Bhat, K. L.; Udupa, K. Rajendra; Hegde, M. M. Rajath

    2011-01-01

    An attempt has been made to evaluate the suitability of austempered ductile iron (ADI) as media material for grinding iron ore in a ball mill. Spheroidal graphite (S.G) iron balls are austenitised at 900° C for 60 minutes and given stepped austempering treatment at 280° C for 30 minutes and 60 minutes followed by 380° C for 60 minutes in each case. These materials are characterised by measuring hardness, analysing X-ray diffraction (X-RD), studying microstructure using optical and scanning electron microscope (SEM). Grinding wear behaviour of these materials was assessed for wear loss in wet condition at different pH value of the mineral slurry and found that the wear rate of grinding media material decreases with increase in pH of the slurry. The wear resistance of ADI balls were compared with forged En31 steel balls and found that the stepped austempered ductile iron is superior to forged En31 steel balls.

  8. Iron ore pollution in Mandovi and Zuari estuarine sediments and its fate after mining ban.

    PubMed

    Kessarkar, Pratima M; Suja, S; Sudheesh, V; Srivastava, Shubh; Rao, V Purnachandra

    2015-09-01

    Iron ore was mined from the banded iron formations of Goa, India, and transported through the Mandovi and Zuari estuaries for six decades until the ban on mining from September 2012. Here we focus on the environmental magnetic properties of sediments from the catchment area, upstream and downstream of these estuaries, and adjacent shelf during peak mining time. Magnetic susceptibility (? lf) and saturation isothermal remanent magnetization (SIRM) values of sediments were highest in upstream (catchment area and estuaries), decreased gradually towards downstream (catchment area and estuaries), and were lowest on the adjacent shelf. The ? lf values of the Mandovi estuary were two to fourfold higher than those in the Zuari. The sediments of these two estuaries after the mining ban showed enrichment of older magnetite and sharp decrease in the SIRM values. Although the input of ore material has been reduced after mining ban, more flushing of estuarine sediments is required for healthier environment. PMID:26271913

  9. Magmatic origin of giant ‘Kiruna-type’ apatite-iron-oxide ores in Central Sweden

    PubMed Central

    Jonsson, Erik; Troll, Valentin R.; Högdahl, Karin; Harris, Chris; Weis, Franz; Nilsson, Katarina P.; Skelton, Alasdair

    2013-01-01

    Iron is the most important metal for modern industry and Sweden is by far the largest iron-producer in Europe, yet the genesis of Sweden's main iron-source, the ‘Kiruna-type’ apatite-iron-oxide ores, remains enigmatic. We show that magnetites from the largest central Swedish ‘Kiruna-type’ deposit at Grängesberg have ?18O values between ?0.4 and +3.7‰, while the 1.90?1.88?Ga meta-volcanic host rocks have ?18O values between +4.9 and +9‰. Over 90% of the magnetite data are consistent with direct precipitation from intermediate to felsic magmas or magmatic fluids at high-temperature (?18Omgt > +0.9‰, i.e. ortho-magmatic). A smaller group of magnetites (?18Omgt ? +0.9‰), in turn, equilibrated with high-?18O, likely meteoric, hydrothermal fluids at low temperatures. The central Swedish ‘Kiruna-type’ ores thus formed dominantly through magmatic iron-oxide precipitation within a larger volcanic superstructure, while local hydrothermal activity resulted from low-temperature fluid circulation in the shallower parts of this system. PMID:23571605

  10. Phosphorus Migration During Direct Reduction of Coal Composite High-Phosphorus Iron Ore Pellets

    NASA Astrophysics Data System (ADS)

    Cheng, Cheng; Xue, Qingguo; Wang, Guang; Zhang, Yuanyuan; Wang, Jingsong

    2015-10-01

    This study investigated the direct reduction process and phosphorus migration features of high-phosphorus iron ores using simulated experiments. Results show that iron oxide was successfully reduced, and a Fe-Si-Al slag formed in carbon-bearing pellets at 1473 K (1200 °C). Fluorapatite then began to decompose into Ca3(PO4)2 and CaF2. As the reaction continued, Ca3(PO4)2 and Fe-Si-Al slag reacted quickly with each other to generate CaAl2Si2O8 and P2, while CaF2 turned into SiF4 gas in the presence of high SiO2. A small amount remained in the slag phase and formed CaAl2Si2O8. Further analysis detailed the migration process of the phosphorus into iron phases, as well as the relationship between carburization and phosphorus absorption in the iron phases. As carbon content in the iron phase increased, the austenite grain boundary melted and formed a large quantity of liquid iron which quickly absorbed the phosphorus. Based on the results of simulation and analysis, this paper proposed a method which reduced the absorption of P by the metallic iron formed and reduced P content in metallic iron during direct reduction.

  11. 26 CFR 1.631-3 - Gain or loss upon the disposal of coal or domestic iron ore with a retained economic interest.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...true Gain or loss upon the disposal of coal or domestic iron ore with a retained economic...631-3 Gain or loss upon the disposal of coal or domestic iron ore with a retained economic...c) apply to an owner who disposes of coal (including lignite), or iron...

  12. 26 CFR 1.631-3 - Gain or loss upon the disposal of coal or domestic iron ore with a retained economic interest.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...true Gain or loss upon the disposal of coal or domestic iron ore with a retained economic...631-3 Gain or loss upon the disposal of coal or domestic iron ore with a retained economic...c) apply to an owner who disposes of coal (including lignite), or iron...

  13. 40 CFR 420.20 - Applicability; description of the sintering subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY...sintering operations conducted by the heating of iron bearing wastes (mill scale and dust from...steelmaking furnaces) together with fine iron ore, limestone, and coke fines in an...

  14. 40 CFR 420.20 - Applicability; description of the sintering subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY...sintering operations conducted by the heating of iron bearing wastes (mill scale and dust from...steelmaking furnaces) together with fine iron ore, limestone, and coke fines in an...

  15. 40 CFR 420.20 - Applicability; description of the sintering subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY...sintering operations conducted by the heating of iron bearing wastes (mill scale and dust from...steelmaking furnaces) together with fine iron ore, limestone, and coke fines in an...

  16. 40 CFR 420.20 - Applicability; description of the sintering subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY...sintering operations conducted by the heating of iron bearing wastes (mill scale and dust from...steelmaking furnaces) together with fine iron ore, limestone, and coke fines in an...

  17. 40 CFR 420.20 - Applicability; description of the sintering subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY...sintering operations conducted by the heating of iron bearing wastes (mill scale and dust from...steelmaking furnaces) together with fine iron ore, limestone, and coke fines in an...

  18. Geology and geochemistry of the Macheng Algoma-type banded iron-formation, North China Craton: Constraints on mineralization events and genesis of high-grade iron ores

    NASA Astrophysics Data System (ADS)

    Wu, Huaying; Niu, Xianglong; Zhang, Lianchang; Pirajno, Franco; Luo, Huabao; Qin, Feng; Cui, Minli; Wang, Changle; Qi, Min

    2015-12-01

    The Macheng iron deposit is located in the eastern Hebei province of the North China Craton (NCC). It is hosted in Neoarchean metamorphic rocks of Baimiaozi formation in the Dantazi Group, consisting of biotite-leptynite, plagioclase-gneiss, plagioclase-amphibolite, migmatite, migmatitic granite and quartz schist. Geochemical analyses of the host biotite leptynite and plagioclase amphibolites show that their protoliths are both volcanics, inferred to be trachytic basalt and basaltic andesite, respectively. Based on the geochemical signature of the host rocks, together with geology of the iron deposit, it is inferred that the Macheng BIF is an Algoma-type iron exhalative formation, formed in an arc-related basin in the Neoarchean. Post-Archean Australian Shale (PAAS)-normalized rare earth elements (REEs) plus yttrium (Y) concentrations of different BIF ores with gneissic, striated and banded structure in the Macheng deposit, show similar patterns with depletions in light rare earth elements (LREEs) and middle rare earth elements (MREEs) relative to heavy rare earth elements (HREEs) and with apparently positive La, Y and Eu anomalies. Y/Ho ratios of the gneissic, striated and banded BIF ores vary from 37 to 56. These geochemical features of the BIF ores reveal their affinity with the sea water and the presence of a high-temperature hydrothermal component, indicating that both the seawater and high temperature hydrothermal fluids derived from alteration of oceanic basalts and komatiites may contribute to formation of the Macheng BIF. Geological, mineralogical and geochemical studies of the Macheng deposit recognized two kinds of high-grade iron ores. One is massive oxidized high-grade ore (Fe2O3T = 74.37-86.20 wt.%), mainly consisting of hematite with some magnetite, which shows geochemical characteristics of the gneissic, striated and banded BIF ores. The other type is magnetite high-grade ore, also massive and consisting of magnetite, with distinct characteristics in trace elements of the gneissic, striated and banded BIF ores but show similarity to those of the migmatitic iron ores with significantly negative Eu anomalies. The geochemical discrepancy or duality between the two types of high-grade ores in Macheng suggests that they formed by two different mechanisms. One is related to supergene enrichment, caused by oxidation of magnetite and the leaching of gangue minerals from BIF to form high-grade ore. The other is probably related to intensive migmatization which produced high-grade ores by altering the primary iron ores.

  19. Assessment of reduction behavior of hematite iron ore pellets in coal fines for application in sponge ironmaking

    SciTech Connect

    Kumar, M.; Patel, S.K.

    2009-07-01

    Studies on isothermal reduction kinetics (with F grade coal) in fired pellets of hematite iron ores, procured from four different mines of Orissa, were carried out in the temperature range of 850-1000C to provide information for the Indian sponge iron plants. The rate of reduction in all the fired iron ore pellets increased markedly with a rise of temperature up to 950C, and thereafter it decreased at 1000C. The rate was more intense in the first 30 minutes. All iron ores exhibited almost complete reduction in their pellets at temperatures of 900 and 950C in 2 hours' heating time duration, and the final product morphologies consisted of prominent cracks. The kinetic model equation 1-(1-a){sup 1/3}=kt was found to fit best to the experimental data, and the values of apparent activation energy were evaluated. Reductions of D. R. Pattnaik and M. G. Mohanty iron ore pellets were characterized by higher activation energies (183 and 150 kJ mol{sup -1}), indicating carbon gasification reaction to be the rate-controlling step. The results established lower values of activation energy (83 and 84 kJ mol{sup -1}) for the reduction of G. M. OMC Ltd. and Sakaruddin iron ore pellets, proposing their overall rates to be controlled by indirect reduction reactions.

  20. Effect of Sintering Temperature on Dielectric Properties of Iron Deficient Nickel-Ferrite

    SciTech Connect

    Rani, Renu; Singh, Sangeeta; Juneja, J. K.; Prakash, Chandra; Raina, K. K.

    2011-11-22

    Nickel Ferrite among all the magneto ceramic materials have been studied very much due to its large number of applications. But there is a large scope of modification of its properties. Thus people still working on it for improvisation of its properties via compositional and structural modifications. Present paper reporting the preparation and characterization of iron deficient Nickel ferrite for different sintering temperature. Ferrite samples having the general formula NiFe1.98O{sub 4} were prepared using the standard ceramic method. The phase formation was confirmed by X-ray diffraction technique. The effect of sintering temperature on the electrical properties and resistivity was studied. The data shows that dielectric properties are highly dependent on the sintering temperature.

  1. Chelatometric determination of calcium and magnesium in iron ores, slags, anorthosite, limestone, copper-nickel-lead-zinc ores and divers materials.

    PubMed

    Hitchen, A; Zechanowitsch, G

    1980-03-01

    Chelatometric methods for the determination of calcium and magnesium in iron ores, slags, anorthosite, copper-nickel-lead-zinc ores and various other materials are described. Potential interfering elements are masked with triethanolamine and potassium cyanide. In one aliquot calcium is titrated at pH > 12, with calcein and thymolphthalein mixed indicator and in another aliquot calcium and magnesium are titrated in ammonia buffer, with o-cresolphthalein complexone screened with Naphthol Green B as indicator. The results compare favourably with certified values for reference materials of diverse nature. PMID:18962661

  2. Carbothermic Reduction of Nickeliferous Laterite Ores for Nickel Pig Iron Production in China: A Review

    NASA Astrophysics Data System (ADS)

    Rao, Mingjun; Li, Guanghui; Jiang, Tao; Luo, Jun; Zhang, Yuanbo; Fan, Xiaohui

    2013-11-01

    Both the consumption and production of crude stainless steel in China rank first in the world. In 2011, the nickel production in China amounted to 446 kilotons, with the proportion of electrolytic nickel and nickel pig iron (NPI) registering 41.5% and 56.5%, respectively. NPI is a low-cost feedstock for stainless steel production when used as a substitute for electrolytic nickel. The existing commercial NPI production processes such as blast furnace smelting, rotary kiln-electric furnace smelting, and Krupp-Renn (Nipon Yakin Oheyama) processes are discussed. As low-temperature (below 1300°C) reduction of nickeliferous laterite ores followed by magnetic separation could provide an alternative avenue without smelting at high temperature (~1500°C) for producing ferronickel with low cost, the fundamentals and recent developments of the low-temperature reduction of nickeliferous laterite ores are reviewed.

  3. Recovery Behavior of Rare Earth from Bayan Obo Complex Iron Ore

    NASA Astrophysics Data System (ADS)

    Ding, Yingui; Xue, Qingguo; Wang, Guang; Wang, Jingsong

    2013-02-01

    A novel process is presented for recovering rare earth from Bayan Obo complex iron ore. The iron ore was reduced and melting separated to produce iron nugget and rare-earth-rich slag. In order to investigate the influence of cooling rate on mineral components, especially the enrichment behavior of RE-containing mineral, the slag was remelted at 1673 K (1400 °C) and the liquid slags were cooled using three types of cooling conditions, water quenching, air cooling, and furnace cooling. Subsequently, the slags were leached by hydrochloric acid to evaluate the relations between leaching efficiency of rare earth and cooling conditions. The results indicated that the slags under different cooling conditions mainly contained fluorite, cefluosil, and cuspidine. The rare-earth mineral is more fully crystallized when the cooling rate of the liquid slag was decreased. The proportion of Ce (III) to Ce (IV) increases with the increase of heating time and decrease of cooling rate. It has been found that the influence of cooling rate on the leaching rate of the rare earth is slight. From water quenching to furnace cooling, the leaching rate of rare earth increases from 97.00 pct to 99.48 pct. After being filtered, filtrate can be used to produce rare-earth chloride. Leached residue, with CaF2 of 64.45 pct and ThO2 of 0.05 pct, can be used to recover CaF2 and extract nuclear source material.

  4. On the influence of porosity on the Portevin-Le Chatelier effect in sintered iron

    SciTech Connect

    Palma, E.S.

    1996-10-01

    Sintered irons of four different porosities were strained in tension at temperatures between 295 (room temperature) and 873 K. Serrated stress-strain curves and high work hardening in the temperature range from 333 to 693 K, for all porosities, were characteristic of dynamic strain aging. The activation energy for the onset of serration was {+-}0.82 eV and was independent of porosity. On the contrary, the parameter {beta} from the relation for dislocation density increased with increasing porosity.

  5. A greenhouse trial to investigate the ameliorative properties of biosolids and plants on physicochemical conditions of iron ore tailings: Implications for an iron ore mine site remediation.

    PubMed

    Cele, Emmanuel Nkosinathi; Maboeta, Mark

    2016-01-01

    An iron ore mine site in Swaziland is currently (2015) in a derelict state as a consequence of past (1964-1988) and present (2011 - current) iron ore mining operations. In order to control problems associated with mine wastes, the Swaziland Water Services Corporation (SWSC) recently (2013) proposed the application of biosolids in sites degraded by mining operations. It is thought that this practice could generally improve soil conditions and enhance plant reestablishment. More importantly, the SWSC foresees this as a potential solution to the biosolids disposal problems. In order to investigate the effects of biosolids and plants in soil physicochemical conditions of iron mine soils, we conducted two plant growth trials. Trial 1 consisted of tailings that received biosolids and topsoil (TUSB mix) while in trial 2, tailings received biosolids only (TB mix). In the two trials, the application rates of 0 (control), 10, 25, 50, 75 and 100 t ha(-1) were used. After 30 days of equilibration, 25 seeds of Cynodon dactylon were sown in each pot and thinned to 10 plants after 4 weeks. Plants were watered twice weekly and remained under greenhouse conditions for 12 weeks, subsequent to which soils were subjected to chemical analysis. According to the results obtained, there were significant improvements in soil parameters related to fertility such as organic matter (OM), water holding capacity (WHC), cation exchange capacity (CEC), ammonium [Formula: see text] , magnesium (Mg(2+)), calcium (Ca(2+)) and phosphorus ( [Formula: see text] ). With regard to heavy metals, biosolids led to significant increases in soil total concentrations of Cu, Zn, Cd, Hg and Pb. The higher concentrations of Zn and Cu in treated tailings compared to undisturbed adjacent soils are a cause for concern because in the field, this might work against the broader objectives of mine soil remediation, which include the recolonization of reclaimed sites by soil-dwelling organisms. Therefore, while biosolids contain important nutrients that may greatly improve physicochemical conditions and enhance vegetation reestablishment in mined soils, the threat of the build-up of higher levels of trace elements in treated tailings compared to surrounding adjacent soils must not be underestimated. PMID:26433357

  6. Study of nonisothermal reduction of iron ore-coal/char composite pellet

    NASA Astrophysics Data System (ADS)

    Dutta, S. K.; Ghosh, A.

    1994-01-01

    Cold-bonded composite pellets, consisting of iron ore fines and fines of noncoking coal or char, were prepared by steam curing at high pressure in an autoclave employing inorganic binders. Dry compressive strength ranged from 200 to 1000 N for different pellets. The pellets were heated from room temperature to 1273 K under flowing argon at two heating rates. Rates of evolution of product gases were determined from gas Chromatographie analysis, and the temperature of the sample was monitored by thermocouple as a function of time during heating. Degree of reduction, volume change, and compressive strength of the pellets upon reduction were measured subsequently. Degree of reduction ranged from 46 to 99 pct. Nonisothermal devolatilization of coal by this procedure also was carried out for comparison. It has been shown that a significant quantity (10 to 20 pct of the pellet weight) of extraneous H2O and CO2 was retained by dried pellets. This accounted for the generation of additional quantities of H2 and CO during heating. Carbon was the major reductant, but reduction by H2 also was significant. Ore-coal and ore-char composites exhibited a comparable degree of reduction. However, the former showed superior postreduction strength due to a smaller amount of swelling upon reduction.

  7. Multi-element analysis of iron ore pellets by Laser-induced Breakdown Spectroscopy and Principal Components Regression

    NASA Astrophysics Data System (ADS)

    Death, D. L.; Cunningham, A. P.; Pollard, L. J.

    2008-07-01

    Laser-induced Breakdown Spectroscopy (LIBS) in combination with Principal Components Regression (PCR) has been applied to determine the elemental composition of a series of run-of-mine (ROM) iron ore samples. The samples were presented for measurement both as compressed pellets and as loose chipped material. The present paper details the results of the measurements of the compressed pellets. Results from ore chips will be reported separately. LIBS spectral data was recorded in three separate spectral regions to measure major, minor and trace components of the iron ore sample pellets. Background stripping, normalization and spectral cleaning were applied to minimize the relative standard deviations of the LIBS data. PCR analysis was then applied to produce calibration models for iron, aluminum, silicon, manganese, potassium and phosphorous. These calibration models were then validated using independent LIBS measurements. Robust calibration models were determined for iron, aluminum, silicon and potassium, whilst the results for manganese were encouraging. Phosphorous, present at low levels in the ores measured, remained the most difficult element to determine accurately. The combination of LIBS and PCR shows potential for in-situ on-line determination of ore composition.

  8. Grinding Wear Behaviour of Stepped Austempered Ductile Iron as Media Material During Comminution of Iron Ore in Ball Mills

    SciTech Connect

    Raghavendra, H.; Bhat, K. L.; Udupa, K. Rajendra; Hegde, M. M. Rajath

    2011-01-17

    An attempt has been made to evaluate the suitability of austempered ductile iron (ADI) as media material for grinding iron ore in a ball mill. Spheroidal graphite (S.G) iron balls are austenitised at 900 deg. C for 60 minutes and given stepped austempering treatment at 280 deg. C for 30 minutes and 60 minutes followed by 380 deg. C for 60 minutes in each case. These materials are characterised by measuring hardness, analysing X-ray diffraction (X-RD), studying microstructure using optical and scanning electron microscope (SEM). Grinding wear behaviour of these materials was assessed for wear loss in wet condition at different pH value of the mineral slurry and found that the wear rate of grinding media material decreases with increase in pH of the slurry. The wear resistance of ADI balls were compared with forged En31 steel balls and found that the stepped austempered ductile iron is superior to forged En31 steel balls.

  9. Phytoremediation: a novel approach for utilization of iron-ore wastes.

    PubMed

    Mohanty, Monalisa; Dhal, Nabin Kumar; Patra, Parikshita; Das, Bisweswar; Reddy, Palli Sita Rama

    2010-01-01

    Large quantities of iron-ore tailings are being generated annually in the world from mining and processing of iron ores. It has been estimated that around 10-15% of the iron ore mined in India has remained unutilized and discarded as slimes during mining and subsequent processing. Soil contamination resulting from mining activities affects surrounding flora and fauna and presents a large clean-up challenge to the mining industry. Innovative new methodologies have been proposed and among the most promising are those that rely on new phytoremediation technology. In this paper we address and review the status of phytoremediation as a technology to reduce and control contaminated mine wastes. Several different approaches and different plant species are used to remove environmentally toxic metals from mine waste sites. Such approaches have the objective of restoring mining waste sites to human and animal use, or at least, to curtail or eliminate the off-site movement of toxic entities that potentially could reach humans. How well phytoremediation performs as an alternative soil restoration technology depends on several factors, including the composition of soil, toxicity level of the contaminant, degree to which plant species fit natural local growth patterns and type of concentration of metal/contaminant in such plants. Phytoremediation has opened prospects for less costly, yet practicable approaches to clean-up contaminated waste sites, particularly those associated with mineral extraction mining. We discuss several plant species that are capable of phytoextracting and/or phytostabilizing harmful elements from contaminated soil and water; such processes are prospectively effective for addressing waste problems that derive from mining and processing activities, as well as those that derive from mitigating the threat posed by waste that surrounds mining sites. Unfortunately, phytoremediation is still in the embryonic stage, and more research is needed to find the plant species that will be most effective for addressing different mining waste scenarios. Such plants must be able to survive and even thrive in heavily contaminated soil and be able to mitigate the pollutants that exist in the soil in which these plants will grow. PMID:20652667

  10. TEM-study of the precipitation of iron in Nd-Fe-B sintered magnets

    SciTech Connect

    Fidler, J.; Tawara, Y.

    1988-03-01

    The authors have extensively studied the microstructure of sintered Nd-Fe-B magnets by means of analytical electron microscopy. The presence of Fe-rich precipitates was first found in magnets showing a small kink in the demagnetization curve, which is an evidence of soft magnetic nucleation centres for reversed magnetic domains within the magnet. ..cap alpha..-iron precipitates occurred outside as well as within the hard magnetic 2:14:1 grains and were also found in other commercial grade magnets with a nominal composition close to Nd 15-Fe77-B8.

  11. Origin and significance of aromatic hydrocarbons in giant iron ore deposits of the late Archean Hamersley Basin,

    E-print Network

    Brocks, Jochen J.

    Origin and significance of aromatic hydrocarbons in giant iron ore deposits of the late Archean extractable saturated and aromatic hydrocarbons. The host rocks belong to the $2.5 billion years (Ga) old Mt and Newman (Mt Whaleback). The saturated hydrocarbons in the rock extracts have the composition of highly

  12. Plant trial of a neutron inelastic scattering gauge for the online analysis of hot reduced iron ores

    NASA Astrophysics Data System (ADS)

    Lim, Cheryl S.; Sowerby, Brian; Rainey, S.; Hardie, G. J.

    1997-02-01

    The HIsmelt Process is a direct smelting process involving a coal-injected smelting reactor with the off-gas passing through a circulating fluidised bed in which fine iron ore is pre-reduced and pre-heated. Control of the pre-reduction system would benefit from an on-line measurement of the degree of pre-reduction (PRD). However, the on-line measurements need to be made on hot ore in circumstances where access to representative sample streams is very difficult. An on-line gauge based on the measurement of neutron inelastic scatter gamma-rays has been installed and calibrated at the HIsmelt plant in Kwinana, Western Australia. The gauge uses an 241Am-Be neutron source and a BGO detector inside a water-cooled tube surrounded by hot iron ore. THe gauge monitors the iron, oxygen, carbon and silica contents of the ore based neutron inelastic scatter gamma-rays at 0.85, 6.13, 4.43 and 1.78 MeV respectively. In plant trials at HIsmelt the gauge determined iron, oxygen, carbon, silica and PRD to within 2.2 wt. percent, 0.6 wt. percent, 0.5 wt. percent, 1.0 wt. percent and 0.4 percent respectively. Potential application so this technology in other direct reduction and smelting processes will also be discussed.

  13. Stemmiulus brasiliensis n. sp., a new species of millipede from Brazilian iron ore caves (Diplopoda: Stemmiulida: Stemmiulidae).

    PubMed

    Iniesta, Luiz Felipe Moretti; Ferreira, Rodrigo Lopes

    2015-01-01

    A new species of Stemmiulus Gervais, 1844 is described from Amazonian iron ore caves located in Pará State, Brazil. The new species differs from the other Brazilian species by gonopod morphology, especially the angiocoxite and colpocoxite, and for the first pairs of legs of males. A key for the species of Stemmiulus found in Brazil is included. PMID:26249465

  14. Effect of Temperature on Morphology of Metallic Iron and Formation of Clusters of Iron Ore Pellets

    NASA Astrophysics Data System (ADS)

    de Alencar, Jean Philippe Santos Gherardi; de Resende, Valdirene Gonzaga; de Castro, Luiz Fernando Andrade

    2015-10-01

    The increase of the reduction temperature in direct reduction furnaces has been a recurring tool due to the benefits that it provides to the process. However, its increase cannot be performed without taking into account some considerations, since the sticking phenomenon is directly correlated with it and could lead to permeability problems and reactor performance. An analysis of the formation of pellets clusters at different temperatures was carried out with focus on morphological characterization of reduced materials to better understand the causes and effects of these actions. The results showed a correlation between the morphology of the metallic iron present in the samples and the clustering index. At low reduction temperatures, 1123 K (850 °C), the iron formed is eroded and deformed and the cluster hardly remains after tumbling. When forming iron with fibrous structure, 1223 K (950 °C), the clustering index increases because of anchor points which make the material to stick together. Finally, under the effect of high temperature and long time, it generates fresh precipitated iron, enhancing the resistance of the clusters so that they cannot be separated.

  15. Microbial Variants from Iron Ore Slimes: Mineral Specificity and pH Tolerance.

    PubMed

    Abhilash; Ghosh, A; Pandey, B D; Sarkar, S

    2015-12-01

    This paper describes the isolation of the native bacterial strains from the iron ore mines slime pond and its extremophilic characteristics. The two microbial isolates designated as CNIOS-1 and CNIOS-2 were grown in selective silicate broth at pH 7.0 and the organisms were tested for their selective adhesion on silicate and alumina minerals. The silicate bacteria with their exopolymers are very potent to grow over aluminosilicates. It was established that CNIOS-1 grew preferentially in the presence of silicate mineral compared to CNIOS-2 which grew in the presence of alumina. The organisms were tested for growth at various pH and trials were carried to define their efficacy for eventual applications to remove gangue minerals of silica and alumina from the raw material. PMID:26543269

  16. A retrospective cohort mortality study of iron ore (hematite) miners in Minnesota.

    PubMed

    Lawler, A B; Mandel, J S; Schuman, L M; Lubin, J H

    1985-07-01

    In a retrospective cohort mortality study of 10,403 Minnesota iron-ore (hematite) miners no excesses of lung cancer mortality were found among either underground (Standardized mortality ratio [SMR] = 100) or above ground (SMR = 88) miners. Yugoslav-born miners incurred a two-fold significant excess mortality for lung cancer that did not appear to be associated with their mining exposures. Significant excesses in mortality due to stomach cancer were found for both underground (SMR = 167) and aboveground (SMR = 181) miners as compared with U.S. white males. However, except among Finnish-born miners, these excesses disappeared when comparisons were made with the appropriate county rate. The apparent absence of significant radon exposure, a strict smoking prohibition underground, an aggressive silicosis control program, and the absence of underground diesel fuel use may explain why these underground miners did not appear to incur the lung cancer risk reported in other studies. PMID:4032088

  17. Effect of Iron Content on Sintering Behavior of Ti-V-Fe-Al Near- ? Titanium Alloy

    NASA Astrophysics Data System (ADS)

    Savvakin, Dmytro G.; Carman, Andrew; Ivasishin, Orest M.; Matviychuk, Mykhailo V.; Gazder, Azdiar A.; Pereloma, Elena V.

    2012-02-01

    Two near- ? Ti-10V-3Fe-3Al and Ti-10V-2Fe-3Al alloys were produced by blended elemental powder metallurgy using hydrogenated titanium and V-Fe-Al master alloy powders. The distributions of the alloying elements were investigated at different stages of transformation of the heterogeneous powder compacts into the final homogeneous alloy product. The influence of iron content on chemical homogenization, densification, microstructure, and mechanical properties of as-sintered alloys was discussed with respect to the fast diffusion mobility of iron in titanium. It was concluded that a 1 pct increase in Fe content, as the alloying element with the fastest diffusivity in titanium, has a positive effect on densification. However, this also results in some grain coarsening of the final material. The attained mechanical properties were comparable with those of cast/wrought near-beta titanium alloys.

  18. Tribological behaviour and statistical experimental design of sintered iron-copper based composites

    NASA Astrophysics Data System (ADS)

    Popescu, Ileana Nicoleta; Ghi??, Constantin; Bratu, Vasile; Palacios Navarro, Guillermo

    2013-11-01

    The sintered iron-copper based composites for automotive brake pads have a complex composite composition and should have good physical, mechanical and tribological characteristics. In this paper, we obtained frictional composites by Powder Metallurgy (P/M) technique and we have characterized them by microstructural and tribological point of view. The morphology of raw powders was determined by SEM and the surfaces of obtained sintered friction materials were analyzed by ESEM, EDS elemental and compo-images analyses. One lot of samples were tested on a "pin-on-disc" type wear machine under dry sliding conditions, at applied load between 3.5 and 11.5 × 10-1 MPa and 12.5 and 16.9 m/s relative speed in braking point at constant temperature. The other lot of samples were tested on an inertial test stand according to a methodology simulating the real conditions of dry friction, at a contact pressure of 2.5-3 MPa, at 300-1200 rpm. The most important characteristics required for sintered friction materials are high and stable friction coefficient during breaking and also, for high durability in service, must have: low wear, high corrosion resistance, high thermal conductivity, mechanical resistance and thermal stability at elevated temperature. Because of the tribological characteristics importance (wear rate and friction coefficient) of sintered iron-copper based composites, we predicted the tribological behaviour through statistical analysis. For the first lot of samples, the response variables Yi (represented by the wear rate and friction coefficient) have been correlated with x1 and x2 (the code value of applied load and relative speed in braking points, respectively) using a linear factorial design approach. We obtained brake friction materials with improved wear resistance characteristics and high and stable friction coefficients. It has been shown, through experimental data and obtained linear regression equations, that the sintered composites wear rate increases with increasing applied load and relative speed, but in the same conditions, the frictional coefficients slowly decrease.

  19. Effectiveness of sodium silicate as gangue depressants in iron ore slimes flotation

    NASA Astrophysics Data System (ADS)

    Rao, Danda Srinivas; Vijayakumar, Tadiparthi Venkata; Rao, Sripada Subba; Prabhakar, Swarna; Raju, Guntamadugu Bhaskar

    2011-10-01

    The recovery of iron from the screw classifier overflow slimes by direct flotation was studied. The relative effectiveness of sodium silicates with different silica-to-soda mole ratios as depressants for silica and silicate bearing minerals was investigated. Silica-to-soda mole ratio and silicate dosage were found to have significant effect on the separation efficiency. The results show that an increase of Fe content in the concentrate is observed with concomitant reduction in SiO2 and Al2O3 levels when a particular type of sodium silicate at a proper dosage is used. The concentrate of 58.89wt% Fe, 4.68wt% SiO2, and 5.28wt% Al2O3 with the weight recovery of 38.74% and the metal recovery of 41.13% can be obtained from the iron ore slimes with 54.44wt% Fe, 6.72wt% SiO2, and 6.80wt% Al2O3, when Na2SiO3 with a silica-to-soda mole ratio of 2.19 is used as a depressant at a feed rate of 0.2 kg/t.

  20. Utilization of Lime Fines as an Effective Binder as well as Fluxing Agent for Making Fluxed Iron Ore Pellets

    NASA Astrophysics Data System (ADS)

    Mandal, Arup Kumar; Sarkar, Alok; Sinha, Om Prakash

    2015-06-01

    A laboratory study was carried out to characterize the physical, chemical and mechanical properties of lime fluxed (varying basicity 0-2) hematite iron ore pellets. Lime was used as additive as well as fluxing agent for making iron ore pellets. The effect of additives on different properties of pellets was studied. The findings show that on increasing the addition of lime, more of calcium-alumino-silicate phases were produced as confirmed by SEM-EDAX analysis. These phases have low melting points, which enhances sticking behaviour of pellets, as well as imparts strength to the pellets (resulting increasing compressive strength, tumbler, abrasion and shatter index) but decreases the porosity. The low basicity pellets were found predominantly oxide-bonded, while the high basicity pellets were mostly slag-bonded. This means that the pellet should be fired at sufficiently high enough temperature to generate liquid phases to get the sufficient strength but not so high as to cause the pellets to stick to each other. The obtained properties of these fluxed pellets were compared with the properties of iron ore lump and pellets, which are being used conventionally in the blast furnace for production of iron and steel.

  1. Did the Kiruna iron ores form as a result of a metasomatic or igneous process? New U-Pb and Nd data for the iron oxide apatite ores and their host rocks in the Norrbotten region of northern Sweden

    NASA Astrophysics Data System (ADS)

    Westhues, A.; Hanchar, J. M.; Whitehouse, M. J.; Fisher, C. M.

    2012-12-01

    A number of iron deposits near Kiruna in the Norrbotten region of northern Sweden are of the iron oxide apatite (IOA) type of deposits; also referred to as Kiruna-type deposits. They are commonly considered a subgroup or end-member of iron oxide copper gold (IOCG) deposits, containing no economic grades of copper or gold. Both IOCG and IOA deposits are characterized by abundant low-Ti Fe oxides, an enrichment in REE, and intense sodium and potassium wall-rock alteration adjacent to the ores. Deposits of these types are of a great economic importance, not only for iron, but also for other elements such as rare earth elements (REE) or uranium. Kiruna, the type locality of the IOA type of mineral deposits, is the focus of this study. Despite a century-long mining history and 2500 Mt of iron ore produced in the region to date (with grades of 30 to 70 wt.% Fe), the genesis of these deposits is poorly understood: theories of a magmatic vs. a hydrothermal or metasomatic origin have been debated, and the timing of mineralization of the ores in the Norbotten region has never been directly dated. The results anticipated from this study will provide a better understanding of the nature of the IOA type of mineral deposits and their relation to IOCG deposits such as Olympic Dam in Australia. An array of geochemical methods is used in order to gain insights on the emplacement history of the host rocks, their subsequent alteration, and the ore genesis of these deposits. This includes in situ U/Pb geochronology of zircon, monazite, and titanite to constrain the timing between host rock emplacement, alteration and mineralization. Isotopic data from whole rocks and in situ at mineral scale will provide constraints on the involvement of hydrothermal fluids and their possible sources, as well as on the sources of Fe, U, and the REE. Newly obtained Sm-Nd isotopic data points to distinct source differences between host rocks, ore and alteration related samples. Preliminary in situ U-Pb dating of zircon from both host rock and ore samples confirms a previously documented event around 1880 - 1900 Ma in the Norrbotten region. However, U-Pb in monazite from an ore sample suggests a further event at ca. 1650 Ma, a period of known activity in Fennoscandia. Further investigation and more U-Pb data are needed to confirm those dates and how the iron mineralization is related to those two events. The combination of U-Th-Pb ages, tracer isotopes and trace element abundances at mineral scale (e.g., Lu-Hf in zircon, and Sm-Nd in monazite, apatite, titanite), along with the O isotopic composition of zircon, will be used to decipher whether the Kiruna iron ore deposits are of metasomatic or igneous origin. Overall, the study also intends to develop a predictive model for exploration of similar iron oxide apatite deposits worldwide.

  2. Closed Die Deformation Behavior of Cylindrical Iron-Alumina Metal Matrix Composites During Cold Sinter Forging

    NASA Astrophysics Data System (ADS)

    Prasanna Kumar, Undeti Jacob; Gupta, Pallav; Jha, Arun Kant; Kumar, Devendra

    2015-09-01

    The present paper aims to study the closed die deformation behavior of cylindrical Fe-Al2O3 metal matrix composites (MMCs). Closed die was manufactured by machining the high carbon steel block followed by oil quenching and then finishing. Samples sintered at a temperature of 1100 °C for 1 h were characterized with X-ray diffraction and scanning electron microscopy, which showed the formation of Fe, Al2O3 and nano size FeAl2O4 phases respectively. Density and hardness of the composite samples were determined after sintering. Closed die deformation studies of the prepared composite samples were carried under three different interfacial frictional conditions i.e. dry, solid lubricating and liquid lubricating. Hardness, density and metallographic characterizations were also done for the deformed samples. On comparing the micrographs of the samples before and after deformation it was revealed that in deformed specimens recrystallization has taken place due to the difference in the energy between the strained iron matrix and unstrained alumina reinforcement during closed die forging process. Experimental density of the samples was also verified with the theoretical density using the standard equations. It is expected that the results of the present investigations will be helpful in developing quality MMC components for wide industrial applications.

  3. An Innovative Magnetic Charging Chute to Improve Productivity of Sinter Machine at Rourkela Steel Plant

    NASA Astrophysics Data System (ADS)

    Selvam, Sambandham Thirumalai; Chaudhuri, Subhasis; Das, Arunaba; Singh, Mithilesh Kumar; Mahanta, H. K.

    Sintering is a process in sinter machine for agglomeration of iron ore and other raw material fines into a compact porous mass, i.e., sinter, used in Blast Furnaces as an iron bearing input charge material for hot metal production. 'Permeability' of sinter-bed on sinter machine i.e., the porosity in sinter-bed of charged materials, facilitates atmospheric air passes from the top to bottom across the depth of sinter-bed, when suction created from the bottom of the bed, for efficient heat carry over from top to bottom of the bed for complete burning of charged materials for effective sintering process controls the productivity of the sinter machine. The level of 'permeability' in sinter-bed is depending upon the effectiveness of 'charging chute' in size-wise 'segregation' of charge materials across the depth in sinter-bed, achieved due to differences in the sliding velocities of particles during charging into the moving sinter-bed. The permeability achieved by the earlier conventional 'charging chute' was limited due to its design and positional constraints in sinter machine. Improving the productivity of sinter machine, through increased permeability of sinter bed is successfully achieved through implementation of an innovatively designed and developed, "Magnetic Charging Chute" at Sinter Plant no. 2 of Rourkela Steel Plant. The induced magnetic force on the charged materials while the charge materials dropping down through the charge chute has improved the permeability of sinter bed through an unique method of segregating the para-magnetic materials and the finer materials of the charge materials to top layer of sinter bed along with improved size-wise segregation of charge materials. This has increased the productivity of the sinter machine by 3% and also reduced the solid fuel consumption i.e., coke breeze in input charge materials by 1 kg/t of sinter.

  4. Effect of reduction roasting by using bio-char derived from empty fruit bunch on the magnetic properties of Malaysian iron ore

    NASA Astrophysics Data System (ADS)

    Yunus, Nurul A.; Ani, Mohd H.; Salleh, Hamzah M.; Rashid, Rusila Z. A.; Akiyama, Tomohiro; Purwanto, Hadi; Othman, Nur E. F.

    2014-04-01

    Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bio-char derived from oil palm empty fruit bunch (EFB) was utilized as an energy source for reduction roasting. Mixtures of Malaysian iron ore and the bio-char were pressed into briquettes and subjected to reduction roasting processes at 873-1173 K. The extent of reduction was estimated on the basis of mass loss, and the magnetization of samples was measured using a vibrating sample magnetometer (VSM). When reduced at 873 K, the original goethite-rich ore was converted into hematite. An increase in temperature to 1073 K caused a significant conversion of hematite into magnetite and enhanced the magnetic susceptibility and saturation magnetization of samples. The magnetic properties diminished at 1173 K as the iron ore was partially reduced to wustite. This reduction roasting by using the bio-char can assist in upgrading the iron ore by improving its magnetic properties.

  5. Utilization of waste polyethylene terephthalate as a reducing agent in the reduction of iron ore composite pellets

    NASA Astrophysics Data System (ADS)

    Polat, Gökhan; Birol, Burak; Sar?dede, Muhlis Nezihi

    2014-08-01

    The increasing consumption of plastics inevitably results in increasing amounts of waste plastics. Because of their long degradation periods, these wastes negatively affect the natural environment. Numerous studies have been conducted to recycle and eliminate waste plastics. The potential for recycling waste plastics in the iron and steel industry has been underestimated; the high C and H contents of plastics may make them suitable as alternative reductants in the reduction process of iron ore. This study aims to substitute plastic wastes for coal in reduction melting process and to investigate their performance during reduction at high temperature. We used a common type of waste plastic, polyethylene terephthalate (PET), because of its high carbon and hydrogen contents. Composite pellets containing PET wastes, coke, and magnetite iron ore were reduced at selected temperatures of 1400 and 1450°C for reduction time from 2 to 10 min to investigate the reduction melting behavior of these pellets. The results showed that an increased temperature and reduction time increased the reduction ratio of the pellets. The optimum experimental conditions for obtaining metallic iron (iron nuggets) were reduction at 1450°C for 10 min using composite pellets containing 60% PET and 40% coke.

  6. THE REMEDIATION OF ABANDONED IRON ORE MINE SUBSIDENCE IN ROCKAWAY TOWNSHIP, NEW JERSEY

    SciTech Connect

    Gary Gartenberg

    2003-12-01

    This report represents the thirteenth Technical Progress Report issued in connection with the subsidence remediation projects undertaken by Rockaway Township in Morris County, New Jersey. This report provides a summary of the major project work accomplished during this semi annual reporting period and contemplated for the subsequent reporting period. This report is issued as part of the project reporting provisions set forth in the Cooperators Agreement between the United States Government--Department of Energy, and Rockaway Township. The purpose of the Cooperators Agreement is for the Department of Energy to provide technical and financial assistance in a coordinated effort with Rockaway Township to develop and implement a multi-phased plan to remediate ground stability problems associated with abandoned mining activity. Primarily during the 1800's, extensive iron ore mining and prospecting was undertaken in Rockaway Township, part of the Dover District Mining region in Morris County. The abandoned mining activity has resulted in public safety hazards associated with ground collapse and surface subsidence features evolving in both developed and undeveloped areas within Rockaway Township. At the Green Pond Mine site at the Township's Jacobs Road Compost Storage Facility, construction was completed during this reporting period and surface monitoring began. Surface monitoring was conducted periodically at the Mt. Hope Road subsidence work area and adjacent areas after the January 2000 construction effort.

  7. THE REMEDIATION OF ABANDONED IRON ORE MINE SUBSIDENCE IN ROCKAWAY TONWSHIP, NEW JERSEY

    SciTech Connect

    Gary Gartenberg

    2003-02-01

    This report represents the tenth Semi-Annual Technical Progress Report issued in connection with the subsidence remediation projects undertaken by Rockaway Township in Morris County, New Jersey. This report provides a summary of the major project work accomplished during this reporting period and contemplated for the subsequent reporting period. This report is issued as part of the project reporting provisions set forth in the Cooperators Agreement between the United States Government-Department of Energy, and Rockaway Township. The purpose of the Cooperators Agreement is for the Department of Energy to provide technical and financial assistance in a coordinated effort with Rockaway Township to develop and implement a multi-phased plan to remediate ground stability problems associated with abandoned mining activity. Primarily during the 1800's, extensive iron ore mining and prospecting was undertaken in Rockaway Township, part of the Dover District Mining region in Morris County. The abandoned mining activity has resulted in public safety hazards associated with ground collapse and surface subsidence features evolving in both developed and undeveloped areas within Rockaway Township. At the Green Pond Mine site at the Township Compost Storage Facility, engineering continued during this reporting period toward development of the Construction Plans and Technical Specifications for the remediation work. At the Mt. Hope Road subsidence, surface monitoring was conducted periodically at the work area and adjacent areas after the January 2000 construction effort.

  8. Production and blast-furnace smelting of boron-alloyed iron-ore pellets

    SciTech Connect

    A.A. Akberdin; A.S. Kim

    2008-08-15

    Industrial test data are presented regarding the production (at Sokolovsk-Sarbaisk mining and enrichment enterprise) and blast-furnace smelting (at Magnitogorsk metallurgical works) of boron-alloyed iron-ore pellets (500000 t). It is shown that, thanks to the presence of boron, the compressive strength of the roasted pellets is increased by 18.5%, while the strength in reduction is doubled; the limestone consumption is reduced by 11%, the bentonite consumption is halved, and the dust content of the gases in the last section of the roasting machines is reduced by 20%. In blast-furnace smelting, the yield of low-sulfur (<0.02%) hot metal is increased from 65-70 to 85.1% and the furnace productivity from 2.17-2.20 to 2.27 t/(m{sup 3} day); coke consumption is reduced by 3-8 kg/t of hot metal. The plasticity and stamping properties of 08IO auto-industry steel are improved by microadditions of boron.

  9. Interactions between Magnetite Oxidation and Flux Calcination during Iron Ore Pellet Induration

    NASA Astrophysics Data System (ADS)

    Firth, Andrew R.; Garden, John F.

    2008-08-01

    Many chemical reactions take place simultaneously during the induration of iron ore pellets produced from magnetite concentrates. Two of the most important are magnetite oxidation and calcination of carbonate fluxes. The first reaction consumes oxygen diffusing into the pellet, while the second reaction produces carbon dioxide that must diffuse out of the pellet. A mathematical model combining the two reactions and gaseous diffusion within the pellet has been developed to quantify the interaction between the two reactions. This combined mathematical model showed that current induration plant mathematical models for the mass and energy balance around a pellet furnace are inaccurate in treating magnetite oxidation and flux calcination as separate reactions. Assuming separate reactions can lead to an error of up to 20 pct conversion of magnetite at the end of the preheat stage. This combined mathematical model, confirmed by experiments with single pellets, also demonstrated that calcination of fluxes also tends to follow a “shrinking core” model rather than reacting simultaneously across the pellet, as existing whole plant models assume. Modifying induration plant mathematical models in accordance with the findings of this article could lead to further savings in energy costs for pellet plants.

  10. THE REMEDIATION OF ABANDONED IRON ORE MINE SUBSIDENCE IN ROCKAWAY TOWNSHIP, NEW JERSEY

    SciTech Connect

    Gary Gartenberg, P.E., P.P.

    1999-10-01

    This report represents the fourth Semi-Annual Technical Progress Report issued in connection with the subsidence remediation projects undertaken by Rockaway Township in Morris County, New Jersey. This report provides a summary of the major project work accomplished during this reporting period and contemplated for the subsequent reporting period. This report is issued as part of the project reporting provisions set forth in the Cooperators Agreement between the United States Government--Department of Energy, and Rockaway Township. The purpose of the Cooperators Agreement is for the Department of Energy to provide technical and financial assistance in a coordinated effort with Rockaway Township to develop and implement a multi-phased plan to remediate ground stability problems associated with abandoned mining activity. Primarily during the 1800's, extensive iron ore mining and prospecting was undertaken in Rockaway Township, part of the Dover District Mining region in Morris County. The abandoned mining activity has resulted in public safety hazards associated with ground collapse and surface subsidence features evolving in both developed and undeveloped areas within Rockaway Township. During this reporting period the Engineering Design for remediation of the surface safety hazards associated with the White Meadow Mine was completed. Construction Plans and Technical Specifications were completed and competitive bids were solicited by the Township for completion of the work. The electrical resistivity survey analysis and report was completed for the Green Pond Mines site at the Township Compost Storage Facility. The geophysical survey results confirmed evidence of abandoned mining activity at the Green Pond Mine site which was previously identified. During this reporting period, the time frame of the Cooperative Agreement between the Township and the Department of Energy was extended. An additional site of subsidence with in the Township related to abandoned mining activity at Mount Hope Road was selected by Rockaway Township to be considered for remediation and inclusion under the Cooperative Agreement.

  11. THE REMEDIATION OF ABANDONED IRON ORE MINE SUBSIDENCE IN ROCKAWAY TOWNSHIP, NEW JERSEY

    SciTech Connect

    Gary Gartenberg, P.E., P.P.

    2001-04-01

    This report represents the sixth Semi-Annual Technical Progress Report issued in connection with the subsidence remediation projects undertaken by Rockaway Township in Morris County, New Jersey. This report provides a summary of the major project work accomplished during this reporting period and contemplated for the subsequent reporting period. This report is issued as part of the project reporting provisions set forth in the Cooperators Agreement between the United States Government--Department of Energy, and Rockaway Township. The purpose of the Cooperators Agreement is for the Department of Energy to provide technical and financial assistance in a coordinated effort with Rockaway Township to develop and implement a multi-phased plan to remediate ground stability problems associated with abandoned mining activity. Primarily during the 1800's, extensive iron ore mining and prospecting was undertaken in Rockaway Township, part of the Dover District Mining region in Morris County. The abandoned mining activity has resulted in public safety hazards associated with ground collapse and surface subsidence features evolving in both developed and undeveloped areas within Rockaway Township. At the White Meadow Mine site, after amended specifications were prepared and continued negotiations took place with the Property Owner, the property ownership was transferred during the reporting period. As a result in the change in property ownership, the remediation project was then to be done by the new Property Owner out of the responsibility of Rockaway Township under this Cooperators Agreement. At the Mt. Hope Road subsidence, surface monitoring was conducted at the work area and adjacent areas after the January 2000 construction effort. At the Green Pond Mine site at the Township Compost Storage Facility, no additional field work was undertaken during this reporting period subsequent to the previous completion of the geophysical survey. With the termination of the White Meadow Mine project, work began toward development of a remedial design for the Green Pond Mines.

  12. The Remediation of Abandoned Iron Ore Mine Subsidence in Rockaway Township, New Jersey

    SciTech Connect

    Gartenberg, Gary; Poff, Gregory

    2010-06-30

    This report represents the twenty-seventh and Final Technical Progress Report issued in connection with the subsidence remediation projects undertaken by Rockaway Township in Morris County, New Jersey. This report provides a summary of the major project work accomplished during this last reporting period ending June 30, 2010 and a summary of the work accomplished since the agreement inception in 1997. This report is issued as part of the project reporting provisions set forth in the Cooperatorâ??s Agreement between the United States Government - Department of Energy, and Rockaway Township. The purpose of the Cooperatorâ??s Agreement is for the Department of Energy to provide technical and financial assistance in a coordinated effort with Rockaway Township to develop and implement a multi-phased plan to remediate ground stability problems associated with abandoned mining activity. Primarily during the 1800â??s, extensive iron ore mining and prospecting was undertaken in Rockaway Township, part of the Dover District Mining region in Morris County. The abandoned mining activity has resulted in public safety hazards associated with ground collapse and surface subsidence features evolving in both developed and undeveloped areas within Rockaway Township. At the Green Pond Mine site at the Townshipâ??s Jacobs Road Compost Storage Facility, surface monitoring continued after completion of construction in September 2003. Surface monitoring was conducted periodically at the Mt. Hope Road subsidence work area and adjacent areas after the January 2000 construction effort. In March 2007, a seventh collapse occurred over a portion of the White Meadow Mine in a public roadway at the intersection of Iowa and Erie Avenues in Rockaway Township. After test drilling, this portion of the mine was remediated by drilling and grouting the stopes.

  13. THE REMEDIATION OF ABANDONED IRON ORE MINE SUBSIDENCE IN ROCKAWAY TOWNSHIP, NEW JERSEY

    SciTech Connect

    Gary Gartenberg, P.E., P.P.

    2001-04-01

    This report represents the seventh Semi-Annual Technical Progress Report issued in connection with the subsidence remediation projects undertaken by Rockaway Township in Morris County, New Jersey. This report provides a summary of the major project work accomplished during this reporting period and contemplated for the subsequent reporting period. This report is issued as part of the project reporting provisions set forth in the Cooperators Agreement between the United States Government--Department of Energy, and Rockaway Township. The purpose of the Cooperators Agreement is for the Department of Energy to provide technical and financial assistance in a coordinated effort with Rockaway Township to develop and implement a multi-phased plan to remediate ground stability problems associated with abandoned mining activity. Primarily during the 1800's, extensive iron ore mining and prospecting was undertaken in Rockaway Township, part of the Dover District Mining region in Morris County. The abandoned mining activity has resulted in public safety hazards associated with ground collapse and surface subsidence features evolving in both developed and undeveloped areas within Rockaway Township. At the Green Pond Mine site at the Township Compost Storage Facility, research and preliminary design was performed during this reporting period toward development of the engineering plans and Technical Specifications for the remediation work. At the White Meadow Mine site, the remediation project was conducted last reporting period by others, out of the responsibility of Rockaway Township under this Cooperators Agreement. At the Mt. Hope Road subsidence, surface monitoring was conducted at the work area and adjacent areas after the January 2000 construction effort.

  14. Petrogenesis and Fluid inclusions of the Band-e Narges skarn iron ore, Central Iran

    NASA Astrophysics Data System (ADS)

    Nazari, Maliheh; Lotfi, Mohammad; Omran, Neematollah R. N.

    2015-04-01

    The Band Narges iron deposit is located approximately 205km NE of Isfhan and is a small area in the NE of Urumieh- Dokhtar Magmatic Arc, Iran. The skarn hosted in a Cretaceous limestone, intruded by granite and granodiorite. The calcic skarn has experienced two stages of metamorphism: 1) prograde stage, which include endoskarn and exoskarnfacies with clinopyroxene, garnet, scapolite and albite mineralization, and 2) retrograde stage which produced actinolite, epidote, chlorite and apatite assemblage through retrograde alteration. The ore minerals in Band-e Nargesskarn are magnetite, with minor chalcopyrite, pyrrhotite and pyrite. Gange minerals are predominantly diopside, andradite, epidote, chlorite, quartz and calcite. Micro-thermometric measurements yield a homogenization temperature range for skarn alteration of 414 to 448°C, with a salinity of 11 to 13.186 wt.%NaCl equivalent. Fluid inclusions in calcite associated with mineralization generally consist of a vapor bubble and a liquid phase with a rare occurrence of three-phase inclusions. Homogenization temperatures for two phase inclusions vary from 168 °C to 203 °C with a salinity of 0.5 to 2 wt% NaCl equivalent. Homogenization of three phase inclusions was observed between 162 °C to 278 °C with salinity of 4 to 23 wt.%NaCl equivalent. The high-temperature and high-salinity of fluids indicate magmatic nature of the trapped fluids within progradeskarn mineral assemblages in contrast the fluids with lower temprature and lower salinity displaying a possible meteoric source within the retrograde skarn assemblages. Therefore moderate temperature and high-salinity fluids could infer to possible isothermal mixing between the fluids. Key word:Skarn,Band-e Narges,fluid inclusion

  15. Roasting-induced phase change and its influence on phosphorus removal through acid leaching for high-phosphorus iron ore

    NASA Astrophysics Data System (ADS)

    Yang, Min; Zhu, Qing-shan; Fan, Chuan-lin; Xie, Zhao-hui; Li, Hong-zhong

    2015-04-01

    In the present study, roasting-induced phase change and its influence on phosphorus removal via leaching has been investigated for high-phosphorus iron ore. The findings indicate that phosphorus in the ore is associated with goethite and exists mainly in amorphous Fe3PO7 phase. The phosphorus remains in the amorphous phase after being roasted below 300°C. Grattarolaite (Fe3PO7) is found in samples roasted at 600-700°C, revealing that phosphorus phase is transformed from the amorphous form to crystalline grattarolaite during roasting. Leaching tests on synthesized pure grattarolaite reveal a low rate of phosphorus removal by sulfuric acid leaching. When the roasting temperature is higher than 800°C, grattarolaite is found to react with alumina to form aluminum phosphate, and the reactivity of grattarolaite with alumina increases with increasing roasting temperature. Consequently, the rate of phosphorus removal also increases with increasing roasting temperature due to the formation of acid-soluble aluminum phosphate.

  16. Underground mining, smoking, and lung cancer: a case-control study in the iron ore municipalities in northern Sweden.

    PubMed

    Damber, L; Larsson, L G

    1985-06-01

    A case-control study of lung cancer in males was performed in two municipalities in northern Sweden with large iron ore mines. Previous studies had revealed an increased lung cancer risk for underground workers in these mines, with all probability related to radon daughter exposure. Data concerning underground mining and smoking were obtained from questionnaires. All analyses suggested an interaction of a multiplicative type between underground mining and smoking in the causation of lung cancer in this population. The calculated population etiologic fraction was about 45% for underground mining and about 80% for smoking. PMID:3858594

  17. Structural-chemical features and morphology of glauconites in sedimentary iron ore of Bakchar prospect (Western Siberia)

    NASA Astrophysics Data System (ADS)

    Rudmin, M.; Reva, I.; Gunko, A.; Mazurov, A.; Abramova, R.

    2015-11-01

    The research embraces the investigation results of glauconites in Bakchar iron ore occurrences to evaluate the potential diversified commercial application of this mineral. The following lab methods were used to analyze the morphology, chemical composition and structure of glauconites: granulometric analysis, optical microscopy, electron microscopy, X-ray fluorescence analysis, atomic arc-emission analysis and infrared spectroscopy. Glauconite was classified according to morphology and grain color and chemical composition and some specific characteristics were also determined (relative content of absorbed water, random distribution of smectite flakes within the grain structures). The research results showed that pistacho-green glauconite grains are less subjected to alteration than greenish-yellow grains due to the content of potassium, iron, absorbed water and organic impurities.

  18. Acidity measurement of iron ore powders using laser-induced breakdown spectroscopy with partial least squares regression.

    PubMed

    Hao, Z Q; Li, C M; Shen, M; Yang, X Y; Li, K H; Guo, L B; Li, X Y; Lu, Y F; Zeng, X Y

    2015-03-23

    Laser-induced breakdown spectroscopy (LIBS) with partial least squares regression (PLSR) has been applied to measuring the acidity of iron ore, which can be defined by the concentrations of oxides: CaO, MgO, Al?O?, and SiO?. With the conventional internal standard calibration, it is difficult to establish the calibration curves of CaO, MgO, Al?O?, and SiO? in iron ore due to the serious matrix effects. PLSR is effective to address this problem due to its excellent performance in compensating the matrix effects. In this work, fifty samples were used to construct the PLSR calibration models for the above-mentioned oxides. These calibration models were validated by the 10-fold cross-validation method with the minimum root-mean-square errors (RMSE). Another ten samples were used as a test set. The acidities were calculated according to the estimated concentrations of CaO, MgO, Al?O?, and SiO? using the PLSR models. The average relative error (ARE) and RMSE of the acidity achieved 3.65% and 0.0048, respectively, for the test samples. PMID:25837118

  19. 3D Inversion of airborne gravity gradiomentry for iron ore exploration in Brazil Cericia Martinez,Yaoguo Li, Richard Krahenbuhl, Marco Braga

    E-print Network

    of Geophysics, Colorado School of Mines Companhia Vale do Rio Doce, Brazil SUMMARY We present the 3D inversion the opportunity for comparing geophysical inversion re- sults with known geology. BACKGROUND Geology Figure 13D Inversion of airborne gravity gradiomentry for iron ore exploration in Brazil Cericia Martinez

  20. Use of silicate shells to prevent sintering during thermally induced chemical ordering of iron platinum nanoparticles

    NASA Astrophysics Data System (ADS)

    Reed, Dwayne Fitzgerald

    Its very high value of magnetocrystalline anisotropy makes the L1 0 phase of FePt a leading candidate for future high density magnetic recording systems. FePt nanoparticles can be prepared by a number of chemical methods. However, these particles have a face-centered cubic structure, with low anisotropy and are superparamagnetic. They must be heated to temperatures above 500 °C to obtain the chemically ordered L10 phase. However, during heating the particles coalesce to give twinned grains with large sizes (10-30 nm). Here we provide a solution to the sintering problem by developing a sol-gel procedure for coating the FePt particles with an amorphous silica shell. The silica shell prevents the FePt particles from agglomerating when heated to 700 °C to effect chemical ordering. FePt nanoparticles were prepared by the super-hydride reduction of platinum(II) acetylacetonate and iron(II) chloride in hot diphenyl ether in the presence of oleylamine and oleic acid capping ligands. The particles had an average diameter of 5-6 nm, a face-centered cubic structure and were superparamagnetic. The particles were coated using a microemulsion process producing a 6 nm silicon oxide shell with a single nanoparticle core-shell structure. The nanoparticles were heated to 700 °C for times of 30 min and 1hr to achieve L10 phase transformation. These samples were annealed in a tube furnace under 95% Ar/5% H2. Many procedures were found to be ineffective. They mostly consisted of biphasic reaction systems and several trials where reaction variables were altered in search of the appropriate conditions. This work has impacted the search for a higher density magnetic recording medium by allowing the study of FePt under a protected environment while achieving chemical ordering. If the L10 FePt nanoparticles will be used in magnetic recording, the particles will require a hard coating to prevent wear. In the course of the present work, it has been shown that the silicate shells agglomerate to form a continuous silicate matrix.

  1. Decline in the lung cancer hazard: a prospective study of the mortality of iron ore miners in Cumbria.

    PubMed Central

    Kinlen, L J; Willows, A N

    1988-01-01

    The mortality of 1947 Cumbrian iron ore miners has been studied over the period 1939-82 in relation to that among other groups of men in England and Wales: (a) all men, (b) men of similar social class, and (c) men living in similar types of (mainly rural) area. Significant excesses were found for deaths from tuberculosis and respiratory diseases compared with each of the reference populations. Lung cancer showed an excess over that in comparable (mainly rural) areas of England and Wales, as reported in a previous study using a proportionate method of analysis and which covered the period 1948-67 but no appreciable excess after 1967. Reasons for this decline are discussed. PMID:3377997

  2. Spectroscopic characterization of iron ores formed in different geological environments using FTIR, XPS, Mössbauer spectroscopy and thermoanalyses

    NASA Astrophysics Data System (ADS)

    Salama, Walid; El Aref, Mourtada; Gaupp, Reinhard

    2015-02-01

    Application of thermoanalyses, FTIR, XPS and Mössbauer spectroscopic methods can differentiate between iron ores formed in different geological environments. Two types of iron ore are formed in shallow marine environments in the Bahariya Depression, Egypt, yellowish brown ooidal ironstones (type 1) and black mud and fossiliferous ironstones (type 2). Both types were subjected to subaerial weathering, producing a dark brown lateritic (pedogenic) iron ore (type 3). Microscopic investigation indicates goethite is the main mineral in types 1 and 3, while hematite is the main mineral in type 2 and also occurs in type 3. Thermoanalyses indicated the dehydroxylation endothermic peak of goethite of type 1 occurs between 329 and 345 °C, while in type 3 occurs between 284 and 330 °C. This variation can be attributed to the nanocrystalline nature of the pedogenic goethite. The presence of an exothermic peak at 754 °C in type 3 is probably attributed to goethite-hematite phase transformation. FTIR spectroscopy indicated that goethite of type 1 is characterized by the presence of the ?-OH band between 799 and 802 cm-1, the ?-OH between 898 and 904 cm-1 and the bulk hydroxyl stretch between 3124 and 3133 cm-1. Goethite of type 3 is characterized by the absence of the bulk hydroxyl stretch band and the ?-OH and ?-OH are shifted to higher Wavenumbers that can attributed to a relative Al-for Fe-substitution. Hematite is identified by two IR bands; the first is between 464 and 475 cm-1 and at the second is between 540 and 557 cm-1. Quartz is identified in all iron ore types, nitrates are identified in types 1 and 2, but absent in type 3 and Kaolinite is identified in type 2. The Mössbauer spectrum of type 1 is fitted with one magnetic sextet corresponding to goethite with an isomer shift (IS) = 0.374 mm s-1, a quadruple splitting (QS) = -0.27 mm s-1 and a hyperfine magnetic field (BHF) = ?37. The Mössbauer spectrum of type 2 is fitted with one magnetic sextet corresponding to hematite with IS = 0.363 mm s-1, QS = -0.23 mm s-1 and BHF = ?50. The Mössbauer spectrum of type 3 is best fitted with a single doublet corresponding to ferrihydrite and one sextet corresponding to hematite. The XPS survey scans and the high resolution of the Fe 2p3/2 can differentiate between the yellowish-brown and green ooidal laminae of type 1. The XPS survey scans indicate the presence of Fe, O, C, N, Na, Cl, Ca and Si in all laminae, while S, Zn, Ti and P are only restricted to the green laminae. The high resolution of the Fe 2p3/2 indicates that Fe is linked to OH- ligand in the yellowish-brown laminae that correspond to goethite, while Fe is linked to SO42- ligand in the green laminae. The XPS survey scans of types 2 and 3 indicate that Fe is linked to O2- ligand that corresponds to hematite.

  3. Os isotopic composition of steels: Constraints on sources of Os in steel & crustal isotopic evolution of iron ores

    NASA Astrophysics Data System (ADS)

    Chatterjee, R. N.; Lassiter, J. C.

    2013-12-01

    Metal contamination during sample processing is a potential concern in Os-isotope studies. We examined Os concentrations and Os isotopes in industrial steels. Samples include high Cr stainless steels (>10.5% Cr), low alloy steels (>=92% Fe) and high alloy steels (<92% Fe). The chief components used to make steel are iron ore, chromites and coke. Coke is derived from coals that have low Os concentration (~36 ppt) [1]. Chromites in steels are mined from chromitites, which have high average Os concentrations and mantle-like 187Os/188Os ratios (~88 ppb Os, 187Os/188Os ? 0.127×24) [2]. Iron ores used in US steel manufacturing derive chiefly from magnetites mined from iron-bearing formations such as Banded Iron Formations (BIF), which have median Os concentration of ~4.8 ppb and radiogenic 187Os/188Os ? 0.358×388 [3]. Os concentrations in the measured steels span a wide range, from 0.03 to 22 ppb. The 187Os/188Os ratios vary from 0.144-4.12. Such high Os concentrations and radiogenic isotopic compositions confirm that metal contamination can affect Os-isotope compositions during sample processing, particularly for low-[Os] samples. There is no correlation between C and Os concentration in steel, indicating that coke is not a major Os source in steels. Os concentrations in steels are positively correlated with Cr content, suggesting that chromite-derived Os dominates the Os budget in stainless steels. 187Os/188Os is negatively correlated with Cr content, ranging from 0.144-0.195 in high-Cr (>10.5 % Cr) steels but from 0.279-4.12 in low-Cr steels. In addition, there is a positive correlation between 1/Os and 187Os/188Os, consistent with two-component mixing of Os derived from magnetite ore and chromites. Lower Os concentrations in steels than expected from simple mixing of magnetite and chromitite suggest some volatile Os loss during smelting. Although the current data is limited, the 186Os-187Os trend defined by the steel analyses can be utilized to extrapolate compositions of the end-member chromite and BIF components. 186Os/188Os values in steels range from 0.119830×5 to 0.119842×42, indistinguishable from the upper mantle. Extrapolation of the 186Os-187Os trend to 187Os/188Os values typical for chromites results in an estimated 186Os/188Os value of 0.119832×4, within error of values previously reported for chromites [4,5]. Extrapolation of the chromite-steel trend to the highly radiogenic (continental crust-like) 187Os values found in BIFs results in much greater uncertainty, but the extrapolated value (0.119834×11) is also indistinguishable from the upper mantle. We estimate an upper bound for the initial ?186Os of the 1.8 Ga BIF source of magnetite ore of ~0.3, similar to initial ?186Os in black shales (0.3-0.5) and freshwater Mn-nodule (1.6), but lower than in loess (1-2.4) [6]. Aqueous deposits and precipitates may sample Os derived from crustal sources with systematically lower time-integrated Pt/Os than the sources for loess. [1] Baioumy H.M et al., Chem Geo 2011 [2] Walker R.J et al., GCA 2002 [3] Ripley E.M et al., Chem Geo 2008 [4] Walker R.J et al., EPSL 2005 [5] Brandon A.D et al., Science 1998 [6] McDaniel D.K et al., GCA 2004

  4. Monitoring sintering burn-through point using infrared thermography.

    PubMed

    Usamentiaga, Rubén; Molleda, Julio; Garcia, Daniel F; Bulnes, Francisco G

    2013-01-01

    Sintering is a complex industrial process that applies heat to fine particles of iron ore and other materials to produce sinter, a solidified porous material used in blast furnaces. The sintering process needs to be carefully adjusted, so that the combustion zone reaches the bottom of the material just before the discharge end. This is known as the burn-through point. Many different parameters need to be finely tuned, including the speed and the quantities of the materials mixed. However, in order to achieve good results, sintering control requires precise feedback to adjust these parameters. This work presents a sensor to monitor the sintering burn-through point based on infrared thermography. The proposed procedure is based on the acquisition of infrared images at the end of the sintering process. At this position, infrared images contain the cross-section temperatures of the mixture. The objective of this work is to process this information to extract relevant features about the sintering process. The proposed procedure is based on four steps: key frame detection, region of interest detection, segmentation and feature extraction. The results indicate that the proposed procedure is very robust and reliable, providing features that can be used effectively to control the sintering process. PMID:23939585

  5. Monitoring Sintering Burn-Through Point Using Infrared Thermography

    PubMed Central

    Usamentiaga, Rubén; Molleda, Julio; Garcia, Daniel F.; Bulnes, Francisco G.

    2013-01-01

    Sintering is a complex industrial process that applies heat to fine particles of iron ore and other materials to produce sinter, a solidified porous material used in blast furnaces. The sintering process needs to be carefully adjusted, so that the combustion zone reaches the bottom of the material just before the discharge end. This is known as the burn-through point. Many different parameters need to be finely tuned, including the speed and the quantities of the materials mixed. However, in order to achieve good results, sintering control requires precise feedback to adjust these parameters. This work presents a sensor to monitor the sintering burn-through point based on infrared thermography. The proposed procedure is based on the acquisition of infrared images at the end of the sintering process. At this position, infrared images contain the cross-section temperatures of the mixture. The objective of this work is to process this information to extract relevant features about the sintering process. The proposed procedure is based on four steps: key frame detection, region of interest detection, segmentation and feature extraction. The results indicate that the proposed procedure is very robust and reliable, providing features that can be used effectively to control the sintering process. PMID:23939585

  6. Reduction of iron ore fines by coal fines in a packed bed and fluidized bed apparatus—A comparative study

    NASA Astrophysics Data System (ADS)

    Haque, R.; Ray, H. S.; Mukherjee, A.

    1993-06-01

    Reduction of iron ore fines by coal fines in packed and fluidized beds has been studied. The investigation includes study of the kinetic aspects of reduction, carbon and sulfur content of the direct reduced iron (DRI) produced, and metallography of the products. For both processes, the kinetic data fit the first-order reaction model. Reduction in a fluidized bed is much faster than in a packed bed system. In both cases, DRI contains a substantial amount of free carbon at the initial stages of reduction. At the later stages of reduction, the carbon present in the DRI is mainly in the combined state. For identical temperatures and particle sizes, reaction in fluidized bed is much faster compared to that in a packed bed. At any particular degree of reduction, sulfur content in DRI samples produced by fluidized bed reduction is always more than that of DRI samples produced by packed bed reduction. Scanning electron microscopy (SEM) micrographs reveal that metallic whiskers formed during reduction in packed beds only. These whiskers become more prominent at higher temperatures and longer times.

  7. Spatial Distribution of Iron in Soils and Vegetation Cover Close to an Abandoned Manganese Oxide Ore Mine, Botswana

    NASA Astrophysics Data System (ADS)

    Ekosse, Georges Ivo E.

    This study aimed at establishing the spatial distribution of iron (Fe) in soils and vegetation cover within the periphery of the Kgwakgwe Manganese (Mn) oxides ore abandoned mine in Botswana. Four hundred soil samples and two hundred vegetation samples were obtained from a 4 km2 area close to the mine. Determination of Fe concentrations after acid digestion of samples was performed using an atomic absorption spectrometer equipped with a deuterium background correction. Tests for soil pH and soil colour were complementary to soil chemical analysis. Results were processed using Geographical Information Systems (GIS) and Remote Sensing (RS) techniques with integrated Land and Water Information System (ILWIS), Geosoft Oasis Montaj, ArcGIS and Microsoft Excel software packages. Concentrations of Fe in soils was from 1116.59 to 870766.00 ?g g-1 with a mean of 17593.52 ?g g-1 and for leaves, levels were from 101.2 to 3758.09 ?g g-1 with a mean of 637.07 ?g g-1. Soil pH values ranged from 2.92 to 7.26 and soil colour shades ranged from yellowish red to very dark grey. Gridded soils and vegetation maps show Fe anomalies in different parts of the study area. Values were low in areas located at the mine workings and in the Northwestern part of the study area and high in the north and southern part. Where concentrations of Fe were high in soils, correspondingly high figures were obtained for vegetation cover. Similar trends were obtained for soil pH distribution in the study area. Bedrock geology, topography, Mn mineralization, soil acidity and prevailing oxidizing conditions were governing factors that influenced the concentration and spatial distribution of Fe in the soils and vegetation. The findings further confirm that Fe distribution and its chemistry in the soils and environment around the Kgwakgwe abandoned Mn oxides ore mine have affected the vegetation cover.

  8. Isolation and phylogenetic characterization of iron-sulfur-oxidizing heterotrophic bacteria indigenous to nickel laterite ores of Sulawesi, Indonesia: Implications for biohydrometallurgy

    NASA Astrophysics Data System (ADS)

    Chaerun, Siti Khodijah; Hung, Sutina; Mubarok, Mohammad Zaki; Sanwani, Edy

    2015-09-01

    The main objective of this study was to isolate and phylogenetically identify the indigenous iron-sulfur-oxidizing heterotrophic bacteria capable of bioleaching nickel from laterite mineral ores. The bacteria were isolated from a nickel laterite mine area in South Sulawesi Province, Indonesia. Seven bacterial strains were successfully isolated from laterite mineral ores (strains SKC/S-1 to SKC/S-7) and they were capable of bioleaching of nickel from saprolite and limonite ores. Using EzTaxon-e database, the 16S rRNA gene sequences of the seven bacterial strains were subjected to phylogenetic analysis, resulting in a complete hierarchical classification system, and they were identified as Pseudomonas taiwanensis BCRC 17751 (98.59% similarity), Bacillus subtilis subsp. inaquosorum BGSC 3A28 (99.14% and 99.32% similarities), Paenibacillus pasadenensis SAFN-007 (98.95% and 99.33% similarities), Bacillus methylotrophicus CBMB 205 (99.37% similarity), and Bacillus altitudinis 41KF2b (99.37% similarity). It is noteworthy that members of the phylum Firmicutes (in particular the genus Bacillus) predominated in this study, therefore making them to have the high potential to be candidates for the bioleaching of nickel from laterite mineral ores. To our knowledge, this is the first report on the predominance of the phylum Firmicutes in the Sulawesi laterite mineral ores.

  9. Rare earth elements, S and Sr isotopes and origin of barite from Bahariya Oasis, Egypt: Implication for the origin of host iron ores

    NASA Astrophysics Data System (ADS)

    Baioumy, Hassan M.

    2015-06-01

    Based on their occurrences and relation to the host iron ores, barites are classified into: (1) fragmented barite occurs as pebble to sand-size white to yellowish white barite along the unconformity between the Bahariya Formation and iron ores, (2) interstitial barite is present as pockets and lenses of large and pure crystals inside the iron ores interstitial barite inside the iron ores, and (3) disseminated barite occurs at the top of the iron ores of relatively large crystals of barite embedded in hematite and goethite matrix. In the current study, these barites have been analyzed for their rare earth elements (REE) as well as strontium and sulfur isotopes to assess their source and origin as well as the origin of host iron ores. Barite samples from the three types are characterized by low ?REE contents ranging between 12 and 21 ppm. Disseminated barite shows relatively lower ?REE contents (12 ppm) compared to the fragmented (19 ppm) and interstitial (21 ppm) barites. This is probably due to the relatively higher Fe2O3 in the disseminated barite that might dilute its ?REE content. Chondrite-normalized REE patterns for the three barite mineralizations exhibit enrichment of light rare earth elements (LREE) relative to heavy rare earth elements (HREE) as shown by the high (La/Yb)N ratios that range between 14 and 45 as well as pronounced negative Ce anomalies varying between 0.03 and 0.18. The 87Sr/86Sr ratios in the analyzed samples vary between 0.707422 and 0.712237. These 87Sr/86Sr values are higher than the 87Sr/86Sr ratios of the seawater at the time of barite formation (Middle Eocene with 87Sr/86Sr ratios of 0.70773 to 0.70778) suggesting a contribution of hydrothermal fluid of high Sr isotope ratios. The ?34S values in the analyzed barites range between 14.39‰ and 18.92‰. The lower ?34S ratios in the studied barites compared with those of the seawater at the time of barite formation (Middle Eocene with ?34S ratios of 20-22‰) is attributed to a possible contribution of hydrothermal fluid of low ?34S values that lowered the ?34S values in the studied barites. Rare earth elements distribution and patterns, as well as strontium and sulfur isotopes suggest a mixing of seawater and a hydrothermal fluid as possible sources for barite mineralizations in the Bahariya Oasis. The seawater source is suggested from the low Ce/La ratios, "V" shape of the rare earth patterns and pronounced negative Ce anomalies. On the other hand, the hydrothermal fluid contribution is evident from the low concentrations of rare earth and the deviation in both S and Sr isotopic compositions from those of the seawater during the time of barites formation (Middle Eocene). The relatively heterogeneous Sr and S isotope ratios among the studied barites suggest the Bahariya Formation and Basement Complex as possible sources of the hydrothermal fluids. The similarity in the REE as well as S and Sr isotopic compositions of the three types of barite suggest that they form simultaneously. As the geology and occurrence of the barites suggest a genetic relationship between these barites and the host iron ores, the mixed seawater and hydrothermal sources model of the barites is still applicable for the source of the host iron ores.

  10. Exposure assessment to dust and free silica for workers of Sangan iron ore mine in Khaf, Iran.

    PubMed

    Naghizadeh, Ali; Mahvi, Amir Hossein; Jabbari, Hossein; Derakhshani, Elham; Amini, Hassan

    2011-11-01

    We aimed to conduct an exposure assessment to dust and free silica for workers of Sangan iron ore mine in Khaf, Iran. The maximum concentrations of total dust and free silica were measured in crusher machine station at 801 ± 155 and 26 ± 7 mg/m(3), respectively. Meanwhile, the minimum concentrations were measured in official and safeguarding station at 8.3 ± 2 and 0.012 ± 0.002 mg/m(3), respectively. Also, the maximum concentrations of respirable dust and free silica were measured in Tappeh Ghermez drilling no. 1 at 66 ± 13 and 1.5 ± 0.4 mg/m(3), respectively, while the minimum concentrations were measured in pneumatic hammer at 5.26 ± 3 and 0.01 ± 0.005 mg/m(3), respectively. Considerate to Iranian standard for respirable dust concentrations (0.11 mg/m(3)) and international standards (ACGIH = 0.1 and NIOSH = 0.05 mg/m(3)), it was found that dust and free silica amounts were much higher than national and international standard levels in this mine. PMID:21805121

  11. Preparation and characterization of novel glass-ceramic tile with microwave absorption properties from iron ore tailings

    NASA Astrophysics Data System (ADS)

    Yao, Rui; Liao, SongYi; Dai, ChangLu; Liu, YuChen; Chen, XiaoYu; Zheng, Feng

    2015-03-01

    A novel glass-ceramic tile consisting of one glass-ceramic layer (GC) attaining microwave absorption properties atop ceramic substrate was prepared through quench-heat treatment route derived from iron ore tailings (IOTs) and commercial raw materials (purity range 73-99%). X-ray diffraction (XRD), SEM, Energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), Physical property measurement system (PPMS) and Vector network analyzer (VNA) measurements were carried out to investigate phase, microstructure, magnetic and microwave absorption aspects of the glass-ceramic layer. Roughly 80.6±1.7 wt% borosilicate glass and 19.4±1.7 wt% spinel ferrite with chemical formula of (Zn2+0.17Fe3+0.83)[Fe3+1.17Fe2+0.06Ni2+0.77]O4 were found among the tested samples. Absorption of Electromagnetic wave by 3 mm thick glass-ceramic layer at frequency of 2-18 GHz reached peak reflection loss (RL) of -17.61 dB (98.27% microwave absorption) at 10.31 GHz. Altering the thickness of the glass-ceramic layer can meet the requirements of different level of microwave absorption.

  12. Reducibility of laterite ores

    NASA Astrophysics Data System (ADS)

    Kawahara, M.; Toguri, J. M.; Bergman, R. A.

    1988-04-01

    The reducibility of several types of lateritic nickel bearing ores was investigated. The ores were reduced with hydrogen over a temperature range of 673 to 1273 K and reaction times from 5 to 80 minutes. The fraction of nickel, iron, and cobalt reduced to the metallic state was determined by leaching the reacted samples with a bromine-methanol solution followed by atomic absorption analysis for the individual elements. The reducibility of nickel increased with increasing iron concentration of the ore. Increased reduction temperature greatly raised the amount of nickel reduced for ores with high iron concentrations. The cobalt reducibility decreased with increasing iron concentration of the ore. Changes in reduction temperature affected cobalt reduction less than nickel reduction. The observed changes in reducibility have been attributed to the formation of phases which incorporate nickel and cobalt. The major ore components were plotted on the ternary phase diagram of the SiO2+(Al2O3)-MgO-FeO system. It is shown how this plot can be used to predict the reducibility of different types of lateritic ores.

  13. Geochemistry of Late Mesozoic dioritic porphyries associated with Kiruna-style and stratabound carbonate-hosted Zhonggu iron ores, Middle-Lower Yangtze Valley, Eastern China: Constraints on petrogenesis and iron sources

    NASA Astrophysics Data System (ADS)

    Hou, Tong; Zhang, Zhaochong; Encarnacion, John; Du, Yangsong; Zhao, Zhidan; Liu, Junlai

    2010-10-01

    Several small Mesozoic sodium-rich dioritic porphyries associated with huge iron oxide deposits occur in the Zhonggu iron ore field, in the eastern part of the Middle-Lower Yangtze River Belt (MLYRB) in the Yangtze craton. We present bulk-rock major and trace element and Sr and Nd isotopic compositions of the three representative dioritic porphyries: the Gushan, Hemushan and Baixiangshan dioritic intrusions. These porphyries are significantly enriched in Pb and light rare earth elements (LREE), relative to high field strength elements (HFSE; Nb, Ta and Ti), coupled with the absence of significant Eu anomalies. They exhibit negative ?Nd( t) (- 5.2 to - 6.8), and highly radiogenic Pb ( 206Pb/ 204Pb = 18.27-18.45). The similar geochemical characteristics of these iron ore-bearing dioritic stocks suggest that they were derived from a common parent basaltic melt, which was produced by partial melting of the enriched lithospheric mantle. However, the parental melt experienced assimilation of Yangtze Block upper crust, accompanying the fractionation of plagioclase and clinopyroxene during ascent to the surface, which led to the extreme enrichment of iron in a highly evolved magma. The contribution of phosphorus and potential CO 2 from the country rocks might have been the crucial factor that led to liquid immiscibility and formation of the unique ore-magma type mineralization.

  14. Desilicification and iron activation-reprecipitation in the high-grade magnetite ores in BIFs of the Anshan-Benxi area, China: Evidence from geology, geochemistry and stable isotopic characteristics

    NASA Astrophysics Data System (ADS)

    Li, Hou-Min; Yang, Xiu-Qing; Li, Li-Xing; Zhang, Zhao-Chong; Liu, Ming-Jun; Yao, Tong; Chen, Jing

    2015-12-01

    The high-grade magnetite ores related to banded iron formations (BIFs) in the Anshan-Benxi area, Liaoning Province in China, have been widely interpreted as the product of replacement of protore by epigenetic hydrothermal fluids. The high-grade iron ore reserves in the mining area II (164 million tons) in the Gongchangling (G2) and Qidashan-Wangjiabuzi (QW) iron deposits (11.45 million tons) are the largest deposits in the Anshan-Benxi area. We present a detailed comparison of the geology, geochemical and stable isotopic compositions of the iron ores in the G2 with those in the QW to constrain the role of desilicification and iron activation-reprecipitation in converting the BIFs to high-grade magnetite ores. These two deposits show marked difference in wall-rock alteration, geochemical features, and oxygen and sulfur isotopic compositions. Wall-rock alteration in the G2 is characterized by garnetization, actinolitization, and chloritization, whereas the QW shows chloritization, biotitization and sericitization. The geochemistry of altered rocks in the G2 is characterized by slight REE fractionation, positive Eu and no significant Ce anomalies, whereas the QW is characterized by high ?REE contents, strong REE fractionation, and the absence of significant Eu and Ce anomalies. High-grade iron ores in the G2 show similar ?18OV-SMOW values for magnetite, lower ?18OV-SMOW values for quartz and higher ?34SV-CDT values for pyrite when compared to the BIFs, whereas the QW shows lower ?18OV-SMOW values for magnetite, similar ?18OV-SMOW values for quartz and similar ?34SV-CDT values for pyrite. These features indicate that desilicification process by hypogene alkaline-rich hydrothermal fluids were possibly responsible for the formation of high-grade iron ores in the G2 whereas iron activation-reprecipitation process by migmatitic-hydrothermal fluids generated the high-grade iron orebodies in QW.

  15. Effective adsorption of phosphate from wastewaters by big composite pellets made of reduced steel slag and iron ore concentrate.

    PubMed

    Wang, Hongjuan; Shen, Shaobo; Liu, Longhui; Ji, Yilong; Wang, Fuming

    2015-11-01

    In order to remove phosphate from wastewater, a large plastic adsorption column filled with big phosphate-adsorbing pellets with diameters of 10?mm, heated by electromagnetic induction coils, was conceived. It was found that the prepared big pellets, which were made of reduced steel slag and iron ore concentrate, contain magnetic Fe and Fe3O4. The thermodynamics and kinetics of adsorption of phosphate from synthetic wastewaters on the pellets were studied in this work. The phosphate adsorption on the pellets followed three models of Freundlich, Langmuir and Dubinin-Kaganer-Radushkevick. The maximum phosphate adsorption capacity Qmax of the pellets were 2.46, 2.74 and 2.77?mg/g for the three temperatures of 20°C, 30°C and 40°C, respectively, based on the Langmuir model. The apparent adsorption energies were -12.9?kJ/mol for the three temperatures. It implied that ion exchange was the main mechanism involved in the adsorption processes. The adsorbed phosphate existed on the pellet surface mainly in the form of Fe3(PO4)2. A reduction pre-treatment of the pellet precursor with H2 greatly enhanced pellet adsorption for phosphate. The adsorption kinetics is better represented by a pseudo-first-order model. The adsorbed phosphate amounts were similar for both real and synthetic wastewaters under similar adsorption conditions. The percentage of adsorbed phosphate for a real wastewater increased with increasing pellet concentration and reached 99.2% at a pellet concentration of 64 (g/L). Some specific phosphate adsorption mechanisms for the pellets were revealed and the pellets showed the potential to efficiently adsorb phosphate from a huge amount of real wastewaters in an industrial scale. PMID:26038973

  16. Regional prospecting for iron ores in Bahariya Oasis-El Faiyum area, Egypt, using LANDSAT-1 satellite images

    NASA Technical Reports Server (NTRS)

    Elshazly, E. M.; Abdel-Hady, M. A.; Elghawaby, M. A.; Khawasik, S. M. (principal investigators)

    1976-01-01

    The author has identified the following significant results. New discoveries of iron deposits were registered as a result of the LANDSAT imagery, and the conditions of the already known iron deposits and occurrences were regionally connected and verified.

  17. Dissolution of copper, tin, and iron from sintered tungsten-bronze spheres in a simulated avian gizzard, and an assessment of their potential toxicity to birds.

    PubMed

    Thomas, Vernon G; McGill, Ian R

    2008-05-15

    The rates of dissolution of copper, tin, and iron from sintered tungsten-bronze spheres (51.1%W, 44.4%Cu, 3.9%Sn, 0.6%Fe, by mass) were measured in an in vitro simulated avian gizzard at pH 2.0, and 42C. Most of the spheres had disintegrated completely to a fine powder by day 14. Dissolution of copper, tin, and iron from the spheres was linear over time; all r>0.974; all P<0.001. The mean rate of release of copper, tin, and iron was 30.4 mg, 2.74 mg, and 0.38 mg per g tungsten-bronze per day, respectively. These rates of metal release were compared to those in published studies to determine whether the simultaneous ingestion of eight spheres of 3.48 mm diameter would pose a toxic risk to birds. The potential absorption rates of iron and tin (0.54 mg Fe/day, and 3.89 mg Sn/day) from eight tungsten-bronze spheres of total mass 1.42 g would not prove toxic, based on empirical studies of tin and iron ingestion in waterfowl. The release of 43.17 mg copper/day from eight tungsten-bronze spheres, while exceeding the daily copper requirements of domesticated birds, is far below the levels of copper known to cause copper toxicosis in birds. We conclude that sintered tungsten-bronze material made into gunshot, fishing weights, or wheel balance weights, would not pose a toxic risk to wild birds when ingested. PMID:18313729

  18. Assessment of Vegetation Establishment on Tailings Dam at an Iron Ore Mining Site of Suburban Beijing, China, 7 Years After Reclamation with Contrasting Site Treatment Methods

    NASA Astrophysics Data System (ADS)

    Yan, Demin; Zhao, Fangying; Sun, Osbert Jianxin

    2013-09-01

    Strip-mining operations greatly disturb soil, vegetation and landscape elements, causing many ecological and environmental problems. Establishment of vegetation is a critical step in achieving the goal of ecosystem restoration in mining areas. At the Shouyun Iron Ore Mine in suburban Beijing, China, we investigated selective vegetation and soil traits on a tailings dam 7 years after site treatments with three contrasting approaches: (1) soil covering (designated as SC), (2) application of a straw mat, known as "vegetation carpet", which contains prescribed plant seed mix and water retaining agent (designated as VC), on top of sand piles, and (3) combination of soil covering and application of vegetation carpet (designated as SC+VC). We found that after 7 years of reclamation, the SC+VC site had twice the number of plant species and greater biomass than the SC and VC sites, and that the VC site had a comparable plant abundance with the SC+VC site but much less biodiversity and plant coverage. The VC site did not differ with the SC site in the vegetation traits, albeit low soil fertility. It is suggested that application of vegetation carpet can be an alternative to introduction of topsoil for treatment of tailings dam with fine-structured substrate of ore sands. However, combination of topsoil treatment and application of vegetation carpet greatly increases vegetation coverage and plant biodiversity, and is therefore a much better approach for assisting vegetation establishment on the tailings dam of strip-mining operations. While application of vegetation carpet helps to stabilize the loose surface of fine-structured mine wastes and to introduce seed bank, introduction of fertile soil is necessary for supplying nutrients to plant growth in the efforts of ecosystem restoration of mining areas.

  19. Rainy Periods and Bottom Water Stagnation Initiating Brine Accumulation and Metal Concentrations, 2. Precambrian Gold-Uranium Ore Beds and Banded Iron Formations

    NASA Astrophysics Data System (ADS)

    Rossignol-Strick, Martine

    1987-08-01

    I previously suggested that heavy runoff during the 12,500-7000 years B.P. tropical pluvial period generated bottom water quiescence and reducing conditions making possible sapropel formation, accumulation of brine originating at the sea bottom, and long-term preservation of hydrothermal sulfides in the Red Sea Deeps. I hypothesized the same process to account for two Precambrian strata-bound ores. In the Upper Witwatersrand paleoplacers, South Africa, gold and uranium eroded by running water from upstream greenstones, reached highest concentrations in association with organic matter in carbonaceous seams, and deposited in the distal end of fluvial fans during transgressive phases. I propose that the deep waters over these fans became anoxic when large, sudden floods stratified the water column. The organic matter thus locally preserved concentrated gold and uranium from the partial dissolution of the detrital metallic grains. In the Hamersley basin of Western Australia, banded iron formations (BIF) of the Dales Gorge Member are a major source of iron ore. Regularly fluctuating environmental conditions are shown by repetitious BIF and black shale macrobands. I propose that they were deposited in a confined, silled, deep basin connected with the open ocean. Before initiation of the lowest BIF deposition the active regional thermohaline circulation flushing the deep waters under a rather arid climate diluted and oxidized the Fe2+-rich hydrothermal effluents exhaling from the basin floor. Then, during a strong wet period, heavy runoff scavenging volcanoclastics from the land surface lowered the basin surface water salinity and prevented deepwater renewal. The hydrothermal effluents began to accumulate and progressively concentrated in the quiescent and progressively oxygen-depleted deep water. During this wet initial phase, the massive black, organic-rich pyritic shale at the top of the Mount McRae Shale Member was deposited immediately and conformably underlying the lowest BIF macroband. When aridity returned, the quiescent deep water filling the basin to sill depth had become sufficiently dense to resist its displacement by reactivated vertical circulation. From Fe2+-rich anoxic brine, Fe3+ was precipitated at the anoxic-oxic interface near the photic zone base by biogenic photosynthesis or Fe2+ photooxidation and partially reduced to Fe2+ during its settling through the anoxic water mass. Thus the lowest BIF macroband of the Dales Gorge Member was formed. Once high bottom water density became established, black shale macrobands were formed during recurrent wet periods and BIF macrobands during the intervening arid intervals. The macrobands' wet-arid periodicity is suggestive of control by Milankovitch-type insolation variation. Mesobands and microbands point to shorter climatic cycles. Termination of the system is achieved only by tectonic movements.

  20. The enhancement effect of pre-reduction using zero-valent iron on the solidification of chromite ore processing residue by blast furnace slag and calcium hydroxide.

    PubMed

    Li, Jinchunzi; Chen, Zhonglin; Shen, Jimin; Wang, Binyuan; Fan, Leitao

    2015-09-01

    A bench scale study was performed to assess the effectiveness of the solidification of chromite ore processing residue (COPR) by blast furnace slag and calcium hydroxide, and investigate the enhancement effect of pre-reduction using zero-valent iron (ZVI) on the solidification treatment. The degree of Cr immobilization was evaluated using the Toxicity Characteristic Leaching Procedure (TCLP) as well as the solid waste-extraction procedure for leaching toxicity-sulfuric acid & nitric acid method (Chinese standard HJ/T299-2007). Strength tests and semi-dynamic leaching tests were implemented to investigate the potential for reusing the final treatment product as a readily available construction material. The experimental results showed that the performance of pre-reduction/solidification (S/S) was superior to that of solidification alone. After pre-reduction, all of the S/S treated COPR samples met the TCLP limit for total Cr (5 mg L(-1)), whereas the samples with a COPR content below 40% met the pollution control limit of bricks and building block products (Chinese standard HJ/T 301-2007) produced with COPR for total Cr (0.3 mg L(-1)). At the same time, all of the S/S treated specimens tested were suitable for utilization at certain levels. PMID:25929874

  1. [Solidification/Stabilization of Chromite Ore Processing Residue (COPR) Using Zero-Valent Iron and Lime-Activated Ground Granulated Blast Furnace Slag].

    PubMed

    Chen, Zhong-lin; Li, Jin-chunzi; Wang, Bin-yuan; Fan, Lei-tao; Shen, Ji-min

    2015-08-01

    The solidification/stabilization (S/S) of chromite ore processing residue (COPR) was performed using zero-valent iron (ZVI) and lime-activated ground granulated blast furnace slag (GGBFS). The degree of Cr immobilization was evaluated using the leaching procedure, mineral composition analysis and morphology analysis. Semi-dynamic leaching tests were implemented to investigate the potential for reusing the final treatment product as a readily available construction material. The results showed that after reduction, all of the S/S treated COPR samples met the pollution control limit of bricks and building block products (Chinese standard HJ/T 301-2007) produced with COPR for total Cr (0.3 mg x L(-1)), the compressive strength of all the S/S samples could meet the compressive strength standard (15 MPa) for producing clay bricks, and Cr existed as the specie that bound to Fe/Mn oxides in the S/S samples. At the same time, all of the S/S treated specimens tested were suitable for utilization at certain levels. PMID:26592036

  2. Numerical Analysis of Carbon Monoxide-Hydrogen Gas Reduction of Iron Ore in a Packed Bed by an Euler-Lagrange Approach

    NASA Astrophysics Data System (ADS)

    Natsui, Shungo; Kikuchi, Tatsuya; Suzuki, Ryosuke O.

    2014-12-01

    In recent years, various methods to decrease carbon dioxide emissions from iron and steel making industries have been developed. The latest blast furnace operation design is intended to induce the low reducing agent operation, highly reactive material is considered a promising way to improve reaction efficiency. Another method utilizes hydrogen in the blast furnace process for highly efficient reduction. Mathematical modeling may help to predict complex in-furnace phenomena, including momentum, heat, and mass transport. However, the current macroscopic continuum model gives no information on the individual particles. In this work, a new approach based on the discrete element method was introduced to consider the interaction between particles under fluid flow in accordance with the arrangement and properties of individual particles. We used an Euler-Lagrange method to precisely understand the influence of the reaction conditions on the behavior of coke and ore particles in three dimensions. The heterogeneity of the reaction rate and temperature distribution was observed to be influenced by the particle arrangement. The endothermic and exothermic reactions influenced each other in the packed bed. Temperature distributions nearly correlated with the gas velocity distribution because convection processes greatly affected the reaction rate. Although convection heat transfer was not a dominant issue in the packed bed, promotion of the reaction by a gas flow was effective.

  3. Preparation of pure iron/Ni-Zn ferrite high strength soft magnetic composite by spark plasma sintering

    NASA Astrophysics Data System (ADS)

    Wang, Minggang; Zan, Zhao; Deng, Na; Zhao, Zhankui

    2014-06-01

    A dense microcellular structure is fabricated using micron-sized pure iron powder cladded with 10 wt% Zn0.5Ni0.5Fe2O4 nanopowder by filling the pure iron with Ni-Zn-ferrites composite and subjecting the mixture to a temperature of 600 °C. The SEM image shows that the thickness of cell wall is in the range of 1.0-2.0 ?m, and the inner dimension of the alloy is in the range of 15-40 ?m. By coating Ni-Zn-ferrites, the electrical resistivity is increased. The composite exhibits not only good soft magnetic properties but also good mechanical strength.

  4. VIEW LOOKING WEST OF SINTERING PLANT, HEYL & PATTERSON CAR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW LOOKING WEST OF SINTERING PLANT, HEYL & PATTERSON CAR DUMPER AT BLAST FURNACE NO. 3, BLAST FURNACE NO. 1 ORE BRIDGE IN BACKGROUND. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 3, Donner Avenue, Monessen, Westmoreland County, PA

  5. Mathematical Modeling of the Kinetics of Carbothermic Reduction of Iron Oxides in Ore-Coal Composite Pellets

    NASA Astrophysics Data System (ADS)

    Sun, Kang; Lu, W.-K.

    2009-02-01

    The kinetics of the carbothermic reduction of iron oxides in a composite pellet made of taconite concentrate and high-volatility coal has been studied by means of mathematical modeling that simultaneously takes into account the transfer rates of both the mass and the heat, and the rates of chemical reactions. The computational results, which have been validated with experimental data in the literature, confirm that the overall rate of the carbothermic reduction, which is strongly endothermic, is limited by heat-transfer steps. From a kinetics viewpoint, the optimum composition of the composite pellet is approximately in accordance with the stoichiometry, when CO is assumed to be the sole oxide of carbon in the gas. To raise the temperature of the pellet from its ambient value to furnace temperature, the heat required is greater than that needed for sustaining all chemical reactions, including the Boudouard reaction. The gaseous product consists mainly of CO and H2, except in the very initial stage. The overall observable reaction rate, in terms of the volumetric rate of the generation of gases, peaks at approximately 30 seconds of reaction time.

  6. Mathematical modeling of the kinetics of carbothermic reduction of iron oxides in ore-coal composite pellets

    SciTech Connect

    Sun, K.; Lu, W.K.

    2009-02-15

    The kinetics of the carbothermic reduction of iron oxides in a composite pellet made of taconite concentrate and high-volatility coal has been studied by means of mathematical modeling that simultaneously takes into account the transfer rates of both the mass and the heat, and the rates of chemical reactions. The computational results, which have been validated with experimental data in the literature, confirm that the overall rate of the carbothermic reduction, which is strongly endothermic, is limited by heat-transfer steps. From a kinetics viewpoint, the optimum composition of the composite pellet is approximately in accordance with the stoichiometry, when CO is assumed to be the sole oxide of carbon in the gas. To raise the temperature of the pellet from its ambient value to furnace temperature, the heat required is greater than that needed for sustaining all chemical reactions, including the Boudouard reaction. The gaseous product consists mainly of CO and H{sub 2}, except in the very initial stage. The overall observable reaction rate, in terms of the volumetric rate of the generation of gases, peaks at approximately 30 seconds of reaction time.

  7. Chromium Remediation or Release? Effect of Iron(II) Sulfate Addition on Chromium(VI) Leaching from Columns of Chromite Ore Processing Residue 

    E-print Network

    Geelhoed, Jeanine S; Meeussen, Johannes CL; Roe, Martin J; Hillier, Stephen; Thomas, Rhodri P; Farmer, John G; Paterson, Edward

    2003-01-01

    Chromite ore processing residue (COPR), derived from the so-called high lime processing of chromite ore, contains high levels of Cr(III) and Cr(VI) and has a pH between 11 and 12. Ferrous sulfate, which is used for ...

  8. Effect of powder reactivity on fabrication and properties of NiAl/Al2O3 composite coated on cast iron using spark plasma sintering

    NASA Astrophysics Data System (ADS)

    Beyhaghi, Maryam; Kiani-Rashid, Ali-Reza; Kashefi, Mehrdad; Khaki, Jalil Vahdati; Jonsson, Stefan

    2015-07-01

    Powder mixtures of Ni, NiO and Al are ball milled for 1 and 10 h. X-ray diffractometry and differential thermal analysis show that while ball milling for 1 h produced mechanically activated powder; 10 h ball milling produced NiAl and Al2O3 phases. Dense NiAl/Al2O3 composite coatings are formed on gray cast iron substrate by spark plasma sintering (SPS) technique. The effect of powder reactivity on microstructure, hardness and scratch hardness of NiAl/Al2O3 coatings after SPS is discussed. Results show that in the coating sample made of mechanically activated powder in situ synthesis of NiAl/Al2O3 composite coating is fulfilled and a thicker well-formed diffusion bond layer at the interface between coating and substrate is observed. The diffusion of elements across the bond layers and phase evolution in the bond layers were investigated. No pores or cracks were observed at the interface between coating layer and substrate in any of samples. Higher Vickers hardness and scratch hardness values in coating made of 10 h ball milled powder than in coating fabricated from 1 h ball milled powder are attributed to better dispersion of Al2O3 reinforcement particles in NiAl matrix and nano-crystalline structure of NiAl matrix. Scratched surface of coatings did not reveal any cracking or spallation at coating-substrate interface indicating their good adherence at test conditions.

  9. Spectrophotometric determination of germanium in ores, concentrates, zinc-processing products and related materials with phenylfluorone and cetyltrimethylammonium bromide after separation by iron collection and heptane extraction of germanium tetrachloride.

    PubMed

    Donaldson, E M

    1984-11-01

    A method for determining approximately 0.2 microg/g or more of germanium in ores, concentrates, zinc-processing products and related materials is described. The sample is decomposed by fusion with sodium peroxide and the cooled melt is dissolved in dilute sulphuric acid. Silica, if > 50 mg, is removed by volatilization with hydrofluoric acid. Germanium is separated from sodium salts by co-precipitation with hydrous ferric oxide, the precipitate is dissolved in 3M hydrochloric acid and germanium is subsequently separated from iron(III) and other co-precipitated elements by a single heptane extraction of germanium tetrachloride from approximately 9.4M hydrochloric acid. The extract is washed with 12M hydrochloric acid to remove residual iron(III), then germanium is stripped with water and determined spectrophotometrically with phenylfluorone in a 1.4M hydrochloric acid-0.002M cetyltrimethylammonium bromide medium in the presence of ascorbic acid as a reductant for co-extracted chlorine. The apparent molar absorptivity of the complex is 1.71 x 10(4) l.mole(-1).mm(-1) at 507 nm, the wavelength of maximum absorption. Up to 5 mg of tin(IV), 10 mg of antimony(V) and tungsten(VI) and approximately 50 mg of silica do not interfere. Germanium values are given for some Canadian certified reference ores, concentrates and iron-formation samples and for a metallurgical dust. PMID:18963706

  10. Reduction of Iron-Oxide-Carbon Composites: Part I. Estimation of the Rate Constants

    NASA Astrophysics Data System (ADS)

    Halder, S.; Fruehan, R. J.

    2008-12-01

    A new ironmaking concept using iron-oxide-carbon composite pellets has been proposed, which involves the combination of a rotary hearth furnace (RHF) and an iron bath smelter. This part of the research focuses on studying the two primary chemical kinetic steps. Efforts have been made to experimentally measure the kinetics of the carbon gasification by CO2 and wüstite reduction by CO by isolating them from the influence of heat- and mass-transport steps. A combined reaction model was used to interpret the experimental data and determine the rate constants. Results showed that the reduction is likely to be influenced by the chemical kinetics of both carbon oxidation and wüstite reduction at the temperatures of interest. Devolatilized wood-charcoal was observed to be a far more reactive form of carbon in comparison to coal-char. Sintering of the iron-oxide at the high temperatures of interest was found to exert a considerable influence on the reactivity of wüstite by virtue of altering the internal pore surface area available for the reaction. Sintering was found to be predominant for highly porous oxides and less of an influence on the denser ores. It was found using an indirect measurement technique that the rate constants for wüstite reduction were higher for the porous iron-oxide than dense hematite ore at higher temperatures (>1423 K). Such an indirect mode of measurement was used to minimize the influence of sintering of the porous oxide at these temperatures.

  11. Reduction of iron-oxide-carbon composites: part I. Estimation of the rate constants

    SciTech Connect

    Halder, S.; Fruehan, R.J.

    2008-12-15

    A new ironmaking concept using iron-oxide-carbon composite pellets has been proposed, which involves the combination of a rotary hearth furnace (RHF) and an iron bath smelter. This part of the research focuses on studying the two primary chemical kinetic steps. Efforts have been made to experimentally measure the kinetics of the carbon gasification by CO{sub 2} and wustite reduction by CO by isolating them from the influence of heat- and mass-transport steps. A combined reaction model was used to interpret the experimental data and determine the rate constants. Results showed that the reduction is likely to be influenced by the chemical kinetics of both carbon oxidation and wustite reduction at the temperatures of interest. Devolatilized wood-charcoal was observed to be a far more reactive form of carbon in comparison to coal-char. Sintering of the iron-oxide at the high temperatures of interest was found to exert a considerable influence on the reactivity of wustite by virtue of altering the internal pore surface area available for the reaction. Sintering was found to be predominant for highly porous oxides and less of an influence on the denser ores. It was found using an indirect measurement technique that the rate constants for wustite reduction were higher for the porous iron-oxide than dense hematite ore at higher temperatures (> 1423 K). Such an indirect mode of measurement was used to minimize the influence of sintering of the porous oxide at these temperatures.

  12. Iron

    MedlinePLUS

    Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...

  13. Iron

    MedlinePLUS

    ... are available? Iron is available in many multivitamin-mineral supplements and in supplements that contain only iron. Iron in supplements is often in the form of ferrous sulfate, ferrous gluconate, ferric citrate, or ferric sulfate. Dietary ...

  14. Biogenic nano-magnetite and nano-zero valent iron treatment of alkaline Cr(VI) leachate and chromite ore processing residue

    PubMed Central

    Watts, Mathew P.; Coker, Victoria S.; Parry, Stephen A.; Pattrick, Richard A.D.; Thomas, Russell A.P.; Kalin, Robert; Lloyd, Jonathan R.

    2015-01-01

    Highly reactive nano-scale biogenic magnetite (BnM), synthesized by the Fe(III)-reducing bacterium Geobacter sulfurreducens, was tested for the potential to remediate alkaline Cr(VI) contaminated waters associated with chromite ore processing residue (COPR). The performance of this biomaterial, targeting aqueous Cr(VI) removal, was compared to a synthetic alternative, nano-scale zero valent iron (nZVI). Samples of highly contaminated alkaline groundwater and COPR solid waste were obtained from a contaminated site in Glasgow, UK. During batch reactivity tests, Cr(VI) removal from groundwater was inhibited by ?25% (BnM) and ?50% (nZVI) when compared to the treatment of less chemically complex model pH 12 Cr(VI) solutions. In both the model Cr(VI) solutions and contaminated groundwater experiments the surface of the nanoparticles became passivated, preventing complete coupling of their available electrons to Cr(VI) reduction. To investigate this process, the surfaces of the reacted samples were analyzed by TEM-EDX, XAS and XPS, confirming Cr(VI) reduction to the less soluble Cr(III) on the nanoparticle surface. In groundwater reacted samples the presence of Ca, Si and S was also noted on the surface of the nanoparticles, and is likely responsible for earlier onset of passivation. Treatment of the solid COPR material in contact with water, by addition of increasing weight % of the nanoparticles, resulted in a decrease in aqueous Cr(VI) concentrations to below detection limits, via the addition of ?5% w/w BnM or ?1% w/w nZVI. XANES analysis of the Cr K edge, showed that the % Cr(VI) in the COPR dropped from 26% to a minimum of 4–7% by the addition of 5% w/w BnM or 2% w/w nZVI, with higher additions unable to reduce the remaining Cr(VI). The treated materials exhibited minimal re-mobilization of soluble Cr(VI) by re-equilibration with atmospheric oxygen, with the bulk of the Cr remaining in the solid fraction. Both nanoparticles exhibited a considerable capacity for the remediation of COPR related Cr(VI) contamination, with the synthetic nZVI demonstrating greater reactivity than the BnM. However, the biosynthesized BnM was also capable of significant Cr(VI) reduction and demonstrated a greater efficiency for the coupling of its electrons towards Cr(VI) reduction than the nZVI. PMID:26109747

  15. Geology of the Eymir iron mine, Edremit, Turkey

    USGS Publications Warehouse

    Jacobson, Herbert Samuel; Turet, Erdogan

    1972-01-01

    The Eymir mine near Edremit on Turkey's Aegean coast (long 27?30'E.,1at 39?36'N.) was investigated as part of the Maden Tetkik ve Arama Enstitutsu (MTA)-U. S. Geological Survey (USGS) mineral exploration and training project, for the purpose of increasing the known mineral reserves. Geologic mapping of the mine area indicates that hematite is restricted to argillized, silicified, and pyritized dacite and possibly andesite. Hematite is present as massive replacements, impregnations, disseminations, and fracture fillings. Most of the upper part of the iron deposit consists of a breccia composed mostly of silicifiled dacite fragments in a hematite matrix. The iron deposit was apparently formed in three steps: 1. Argillation, silicification, and pyritization of the andesitic lava and dacite units as a result of a regional intrusion. 2. Intrusion of the Dere Oren dacite stock, with associated faulting, fracturing, and breccia formation at the surface. 3. Deposition of hematite by oxidation of pyrite, and transfer of iron via fractures and faults by hydrothermal or meteoric fluids. The Eymir iron deposit is a blanketlike deposit on the crest of the Sivritepe-Eymir ridge. It is 1300 meters long, 80 to 450 meters wide, and has an average thickness of 18.6 meters. Drill holes in the deposit show the iron content to range from 32.0 to 57.6 percent, and to average 46.5 percent. Most of the gangue is silica, and an arsenic impurity averaging 0.39 percent is present. Most of the deposit cannot be utilized as iron ore because of low iron content, high silica content, and high arsenic content. Ore-dressing tests have shown that it is feasible to concentrate the low-grade material, producing a concentrate having increased iron content and reduced silica content. Tests have shown also that the arsenic content of the ore can be reduced substantially by sintering. Further tests and economic feasibility studies are necessary to determine whether an economic marketable iron ore can be produced. If such studies indicate the technical and economic feasibility of utilizing all the Eymir iron deposit, detailed additional studies are recommended including: 1. A detailed drilling and sampling program to include 60 drill holes averaging 40 meters in depth and detailed sampling of mine dumps. 2. Pilot-plant testing of concentration and sintering procedures. 3. A detailed pre-investment economic feasibility study.

  16. Ferronickel enrichment by fine particle reduction and magnetic separation from nickel laterite ore

    NASA Astrophysics Data System (ADS)

    Tang, Xiao-hui; Liu, Run-zao; Yao, Li; Ji, Zhi-jun; Zhang, Yan-ting; Li, Shi-qi

    2014-10-01

    Ferronickel enrichment and extraction from nickel laterite ore were studied through reduction and magnetic separation. Reduction experiments were performed using hydrogen and carbon monoxide as reductants at different temperatures (700-1000°C). Magnetic separation of the reduced products was conducted using a SLon-100 cycle pulsating magnetic separator (1.2 T). Composition analysis indicates that the nickel laterite ore contains a total iron content of 22.50wt% and a total nickel content of 1.91wt%. Its mineral composition mainly consists of serpentine, hortonolite, and goethite. During the reduction process, the grade of nickel and iron in the products increases with increasing reduction temperature. Although a higher temperature is more favorable for reduction, the temperature exceeding 1000°C results in sintering of the products, preventing magnetic separation. After magnetic separation, the maximum total nickel and iron concentrations are 5.43wt% and 56.86wt%, and the corresponding recovery rates are 84.38% and 53.76%, respectively.

  17. On-line iron-ore slurry monitoring for real-time process control of pellet making processes using laser-induced breakdown spectroscopy: graphitic vs. total carbon detection

    NASA Astrophysics Data System (ADS)

    Barrette, Louis; Turmel, Simon

    2001-06-01

    Chemical composition of iron-ore pellets has a significant impact on their quality and commercial value. Laser-induced breakdown spectroscopy (LIBS) technique has been extensively tested on line, at industrial pelletizing plants. It proved successful at measuring Si, Ca, Mg, Al and graphitic C contents of different iron-ore slurries prior to filtration and pelletizing. For this specific application, the sensitivity of the technique compares with the one obtained from dedicated chemical laboratories. But the real advantage of LIBS technique is that the results are delivered continuously and in real time compared to periodic sampling and standard analytical delays of more than 1 h. Consequently, LIBS gives a more representative reading of the state of the process — particularly when rapid perturbations occur — and allows process optimization and quality improvement. In this work, special attention was given to the fact that the detection system, with specific settings, gives direct measurement for either graphitic carbon (coke breeze) or total carbon (coke breeze, flux and natural carbonate). Graphitic carbon content is a key parameter for both the pellet production cost and its final commercial value. LIBS is a sensitive technique that can detect small variations. But matrix effects affect the spectral lines and it is sometimes difficult to establish universal calibration curve. This problem is partially overcome by the use of a multivariable calibration that corrects for matrix effects and evaluates a confidence level based on expertise for each measurement. Current research is aimed at the development of commercial equipment for continuous industrial use.

  18. PHASE II CALDERON PROCESS TO PRODUCE DIRECT REDUCED IRON RESEARCH AND DEVELOPMENT PROJECT

    SciTech Connect

    Albert Calderon

    2006-04-19

    This project was initially targeted to the making of coke for blast furnaces by using proprietary technology of Calderon in a phased approach, and Phase I was successfully completed. The project was then re-directed to the making of iron units. In 2000, U.S. Steel teamed up with Calderon for a joint effort to produce directly reduced iron with the potential of converting it into molten iron or steel consistent with the Roadmap recommendations of 1998 prepared by the Steel Industry in cooperation with the Department of Energy by using iron ore concentrate and coal as raw materials, both materials being appreciably lower in cost than using iron pellets, briquettes, sinter and coke.

  19. PHASE II CALDERON PROCESS TO PRODUCE DIRECT REDUCED IRON RESEARCH AND DEVELOPMENT PROJECT

    SciTech Connect

    Albert Calderon

    2006-01-30

    This project was initially targeted to the making of coke for blast furnaces by using proprietary technology of Calderon in a phased approach, and Phase I was successfully completed. The project was then re-directed to the making of iron units. In 2000, U.S. Steel teamed up with Calderon for a joint effort to produce directly reduced iron with the potential of converting it into molten iron or steel consistent with the Roadmap recommendations of 1998 prepared by the Steel Industry in cooperation with the Department of Energy by using iron ore concentrate and coal as raw materials, both materials being appreciably lower in cost than using iron pellets, briquettes, sinter and coke.

  20. Phase II Calderon Process to Produce Direct Reduced Iron Research and Development Project

    SciTech Connect

    Albert Calderon

    2007-03-31

    This project was initially targeted to the making of coke for blast furnaces by using proprietary technology of Calderon in a phased approach, and Phase 1 was successfully completed. The project was then re-directed to the making of iron units. In 2000, U.S. Steel teamed up with Calderon for a joint effort to produce directly reduced iron with the potential of converting it into molten iron or steel consistent with the Roadmap recommendations of 1998 prepared by the Steel Industry in cooperation with the Department of Energy by using iron ore concentrate and coal as raw materials, both materials being appreciably lower in cost than using iron pellets, briquettes, sinter and coke.

  1. Evolution of ore deposits on terrestrial planets

    NASA Technical Reports Server (NTRS)

    Burns, R. G.

    1991-01-01

    Ore deposits on terrestrial planets materialized after core formation, mantle evolution, crustal development, interactions of surface rocks with the hydrosphere and atmosphere, and, where life exists on a planet, the involvement of biological activity. Core formation removed most of the siderophilic and chalcophilic elements, leaving mantles depleted in many of the strategic and noble metals relative to their chondritic abundances. Basaltic magma derived from partial melting of the mantle transported to the surface several metals contained in immiscible silicate and sulfide melts. Magmatic ore deposits were formed during cooling, fractional crystallization and density stratification from the basaltic melts. Such ore deposits found in earth's Archean rocks were probably generated during early histories of all terrestrial planets and may be the only types of igneous ores on Mars. Where plate tectonic activity was prevalent on a terrestrial planet, temporal evolution of ore deposits took place. Repetitive episodes of subduction modified the chemical compositions of the crust and upper mantles, leading to porphyry copper and molybdenum ores in calc-alkaline igneous rocks and granite-hosted tin and tungsten deposits. Such plate tectonic-induced mineralization in relatively young igneous rocks on earth may also have produced hydrothermal ore deposits on Venus in addition to the massive sulfide and cumulate chromite ores associated with Venusian mafic igneous rock. Sedimentary ore deposits resulting from mechanical and chemical weathering in reducing atmospheres in Archean earth included placer deposits (e.g., uraninite, gold, pyrite ores). Chromite, ilmenite, and other dense unreactive minerals could also be present on channel floors and in valley networks on Mars, while banded iron formations might underlie the Martian northern plains regions. As oxygen evolved in earth's atmosphere, so too did oxide ores. By analogy, gossans above sulfide ores probably occur on Mars, but not submarine ferromanganese nodules and crusts which have precipitated in oxygenated seawater on earth.

  2. Iron

    MedlinePLUS

    ... avoid taking it with foods containing dairy products, coffee, tea, or cereals. There are many forms of ... Coffee and teaTaking iron supplements with coffee or tea can reduce the amount of iron the body ...

  3. IRON

    EPA Science Inventory

    The document surveys the effects of organic and inorganic iron that are relevant to humans and their environment. The biology and chemistry of iron are complex and only partially understood. Iron participates in oxidation reduction processes that not only affect its geochemical m...

  4. Reduction Mechanisms in Manganese Ore Reduction

    NASA Astrophysics Data System (ADS)

    Coetsee, Theresa; Reinke, Christian; Nell, Johannes; Pistorius, Petrus Christiaan

    2015-12-01

    Manganese ores are highly heterogeneous and contain various minerals with different levels of contained manganese and iron and therefore the ore reduction behavior is not uniform. Both phase chemistry and phase morphology at the reaction interface, at micron scale, must be investigated to understand the reaction mechanism effects in manganese ore reduction. This approach is applied here to reacted material mixture samples taken from the AlloyStream pilot plant furnace over a period of 4 months. The mineralogical features are reported and discussed. Deductions are made on the likely dominant reduction mechanism in this reaction system, given the phase morphology observations presented.

  5. Geochemistry of the furnace magnetite bed, Franklin, New Jersey, and the relationship between stratiform iron oxide ores and stratiform zinc oxide-silicate ores in the New Jersey highlands

    USGS Publications Warehouse

    Johnson, C.A.; Skinner, B.J.

    2003-01-01

    The New Jersey Highlands terrace, which is an exposure of the Middle Proterozoic Grenville orogenic belt located in northeastern United States, contains stratiform zinc oxide-silicate deposits at Franklin and Sterling Hill and numerous massive magnetite deposits. The origins of the zinc and magnetite deposits have rarely been considered together, but a genetic link is suggested by the occurrence of the Furnace magnetite bed and small magnetite lenses immediately beneath the Franklin zinc deposit. The Furnace bed was metamorphosed and deformed along with its enclosing rocks during the Grenvillian orogeny, obscuring the original mineralogy and obliterating the original rock fabrics. The present mineralogy is manganiferous magnetite plus calcite. Trace hydrous silicates, some coexisting with fluorite, have fluorine contents that are among the highest ever observed in natural assemblages. Furnace bed calcite has ??13C values of -5 ?? 1 per mil relative to Peedee belemnite (PDB) and ??18O values of 11 to 20 per mil relative to Vienna-standard mean ocean water (VSMOW). The isotopic compositions do not vary as expected for an original siderite layer that decarbonated during metamorphism, but they are consistent with nearly isochemical metamorphism of an iron oxide + calcite protolith that is chemically and minerlogically similar to iron-rich sediments found near the Red Sea brine pools and isotopically similar to Superior-type banded iron formations. Other magniferous magnite + calcite bodies occur at approximately the same stratigraphic position as far 50 km from the zinc deposits. A model is presented in which the iron and zinc deposits formed along the western edge of a Middle Proterozoic marine basin. Zinc was transported by sulfate-stable brines and was precipitated under sulfate-stable conditions as zincian carbonates and Fe-Mn-Zn oxides and silicates. Whether the zincian assemblages settled from the water column or formed by replacement reactions in shallowly buried sediments is uncertain. The iron deposits formed at interfaces between anoxic and oxygenated waters. The Furnace magnetite bed resulted from seawater oxidation of hydrothermally transported iron near a brine conduit. Iron deposits also formed regionally on the basin floor at the interface betveen anoxic deep waters and oxygenated shallower waters. These deposits include not only manganiferous magnetite + calcite bodies similar to the Furnace magnetite bed but also silicate-facies deposits that formed by iron oxide accumulation where detrital sediment was abundant. A basin margin model can be extended to Grenvillian stratiform deposits in the northwest Adirondacks of New York and the Mont Laurier basin of Quebec. In these areas iron deposits (pyrite or magnetite) are found basinward of marble-hosted sphalerite deposits, such as those in the Balmat-Edwards district. Whether the iron and zinc precipitated as sulfide assemblages or carbonate-oxide-silicate assemblages depended on whether sufficient organic matter or other reductants were available in local sediments or bottom waters to stabilize H2S.

  6. Quantification and analysis of geomorphic processes on a recultivated iron ore mine on the Italian island Elba using long-time ground-based LIDAR and photogrammetric data by an UAV

    NASA Astrophysics Data System (ADS)

    Haas, F.; Hilger, L.; Neugirg, F.; Umstädter, K.; Breitung, C.; Fischer, P.; Hilger, P.; Heckmann, T.; Dusik, J.; Kaiser, A.; Schmidt, J.; Della Seta, M.; Rosenkranz, R.; Becht, M.

    2015-10-01

    This study aims on the quantification and analysis of geomorphic processes on the barely vegetated slopes of a recultivated iron ore mine on the Italian island Elba using Terrestrial Lasercanning (TLS) and digital photogrammetry by UAV photographs over a period of 5 1/2 years. Beside this the study tried to work out the potential and the limitations of both methods to detect surface changes by geomorphic process dynamic within a natural environment. Both, UAV and TLS show the pattern of the erosion and accumulation processes on the investigated slope quite well, but the calculated amounts differ clearly between the methods. The reasons for these differences could be found in the different accuracies (variable level of detections) of the methods and the different viewing geometries. Both effects have an impact on the detectable process dynamic over different time scales on the slope and their calculated amounts, which in both cases can lead to an underestimation of erosion and accumulation by fluvial processes.

  7. Iron

    MedlinePLUS

    ... Guidelines for Americans and the U.S. Department of Agriculture's food guidance system, ChooseMyPlate . Where can I find ... on food sources of iron: U.S. Department of Agriculture's (USDA) National Nutrient Database Nutrient List for Iron ( ...

  8. Sources of ores of the ferroalloy metals

    USGS Publications Warehouse

    Burchard, E.F.

    1933-01-01

    Since all steel is made with the addition of alloying elements, the record of the metallic raw materials contributory to the steel industry would be far from complete without reference to the ferroalloy metals. This paper, therefore, supplements two preceding arvicles on the sources of our iron ores. The photographs, with the exception of those relating to molybdenum and vanadium, are by the author.

  9. Continuous Steelmaking Directly from Ore

    NASA Astrophysics Data System (ADS)

    Warner, Noel A.

    2014-12-01

    In-line continuous processing of high-grade hematite ore (crushed ore or fines) with a pure hydrogen reductant is assessed. An appraisal is made of the rate controlling mechanisms involved in the reduction of a pure layer of molten wustite being transported by floating on a molten carrier iron carbon-free medium at temperatures just in excess of the iron melting point. Published research clearly indicates that under these conditions the kinetics are principally controlled by molecular gaseous diffusion. Thus, the rate is essentially not influenced by total gas pressure above 1 atmosphere. Accordingly, on safety grounds it is recommended that high pressure should not be used for hydrogen steelmaking in the future, but the operation should be conducted close to atmospheric pressure with low pressure steam encapsulation of the plant items involved. Using hydrogen as the reductant means that sub-surface nucleation of CO bubbles cannot disrupt continuous processing. The operation is then no different to processing a normal liquid phase. The off-gases from the reduction zone of a melt circulation loop are super-clean and only contaminated with iron vapor. Accordingly, the best available technology becomes available for energy conservation without risk of non-fusible solids deposition. The net result is that the energy requirements are expected to be superior to other potential processes.

  10. Comparison of first order analysis and Monte Carlo methods in evaluating groundwater model uncertainty: a case study from an iron ore mine in the Pilbara Region of Western Australia

    NASA Astrophysics Data System (ADS)

    Firmani, G.; Matta, J.

    2012-04-01

    The expansion of mining in the Pilbara region of Western Australia is resulting in the need to develop better water strategies to make below water table resources accessible, manage surplus water and deal with water demands for processing ore and construction. In all these instances, understanding the local and regional hydrogeology is fundamental to allow sustainable mining; minimising the impacts to the environment. An understanding of the uncertainties of the hydrogeology is necessary to quantify the risks and make objective decisions rather than relying on subjective judgements. The aim of this paper is to review some of the methods proposed by the published literature and find approaches that can be practically implemented in an attempt to estimate model uncertainties. In particular, this paper adopts two general probabilistic approaches that address the parametric uncertainty estimation and its propagation in predictive scenarios: the first order analysis and Monte Carlo simulations. A case example application of the two techniques is also presented for the dewatering strategy of a large below water table open cut iron ore mine in the Pilbara region of Western Australia. This study demonstrates the weakness of the deterministic approach, as the coefficients of variation of some model parameters were greater than 1.0; and suggests a review of the model calibration method and conceptualisation. The uncertainty propagation into predictive scenarios was calculated assuming the parameters with a coefficient of variation higher than 0.25 as deterministic, due to computational difficulties to achieve an accurate result with the Monte Carlo method. The conclusion of this case study was that the first order analysis appears to be a successful and simple tool when the coefficients of variation of calibrated parameters are less than 0.25.

  11. Iron

    MedlinePLUS

    ... also used for improving athletic performance and treating attention deficit-hyperactivity disorder (ADHD) and canker sores. Some people also use ... body when taken by women who are pregnant.Attention deficit-hyperactivity disorder (ADHD). Developing research shows that taking iron sulfate ( ...

  12. Saugus Iron Works Blast Furnace

    USGS Multimedia Gallery

    A view of the Saugus Iron Works blast furnace, which smelted the iron from limonite, an iron ore. The limonite formed in nearby bogs, and was heated in the blast furnace until the iron melted and ran out the bottom of the furnace....

  13. Limonite at Saugus Iron Works

    USGS Multimedia Gallery

    A specimen of limonite, used in the iron smelting process. Limonite is a well-known iron ore that has been mined for iron for many thousands of years. At the Saugus Iron Works, the limonite was found in nearby bogs....

  14. In situ X-ray diffraction of pyrolite to 40 GPa using Kawai-type apparatus with sintered diamond anvils: possibility for the existence of iron-rich metallic particles in the lower mantle

    SciTech Connect

    Kubo, A.; Ito, E.; Katsura, T.; Fujino, K.; Funakoshi, K.

    2008-11-12

    We investigated phase relations in pyrolite at -33--40 GPa and -1800--2150 K by in situ X-ray diffraction using Kawai-type apparatus with sintered diamond anvils. The results demonstrated that MgSiO{sub 3}-rich orthorhombic perovskite (mpv), CaSiO{sub 3}-rich cubic perovskite (cpv) and (Mg,Fe)O ferropericlase (fp) are the stable phases in pyrolite bulk composition at the conditions corresponding to the lower mantle. However, chemical analyses of a run product recovered from -34 GPa by an analytical transmission electron microscope showed the coexistence of metallic iron particles with mpv, fp, and SiO{sub 2}-rich amorphous phase. Also, Fe/Mg partitioning coefficient between mpv and fp was found to be 0.66(31), which is consistent with previous results for pyrolite bulk composition at 26--30 GPa and -1900 K. These results indicate that iron-rich metallic particles can exist in the lower mantle as a stable phase to the depth of at least -900 km.

  15. Determination of antimony in concentrates, ores and non-ferrous materials by atomic-absorption spectrophotometry after iron-lanthanum collection, or by the iodide method after further xanthate extraction.

    PubMed

    Donaldson, E M

    1979-11-01

    Methods for determining trace and moderate amounts of antimony in copper, nickel, molybdenum, lead and zinc concentrates and in ores are described. Following sample decomposition, antimony is oxidized to antimony(V) with aqua regia, then reduced to antimony(III) with sodium metabisulphite in 6M hydrochloric acid medium and separated from most of the matrix elements by co-precipitation with hydrous ferric and lanthanum oxides. Antimony (>/= 100 mug/g) can subsequently be determined by atomic-absorption spectrophotometry, at 217.6 nm after dissolution of the precipitate in 3M hydrochloric acid. Alternatively, for the determination of antimony at levels of 1 mug/g or more, the precipitate is dissolved in 5M hydrochloric acid containing stannous chloride as a reluctant for iron(III) and thiourea as a complexing agent for copper. Then tin is complexed with hydrofluoric acid, and antimony is separated from iron, tin, lead and other co-precipitated elements, including lanthanum, by chloroform extraction of its xanthate. It is then determined spectrophotometrically, at 331 or 425 nm as the iodide. Interference from co-extracted bismuth is eliminated by washing the extract with hydrochloric acid of the same acid concentration as the medium used for extraction. Interference from co-extracted molybdenum, which causes high results at 331 nm, is avoided by measuring the absorbance at 425 nm. The proposed methods are also applicable to high-purity copper metal and copper- and lead-base alloys. In the spectrophotometric iodide method, the importance of the preliminary oxidation of all of the antimony to antimony(V), to avoid the formation of an unreactive species, is shown. PMID:18962563

  16. Influence of intermediate-heat treatment on the structure and magnetic properties of iron-rich Sm(CoFeCuZr)Z sintered magnets

    NASA Astrophysics Data System (ADS)

    Horiuchi, Yosuke; Hagiwara, Masaya; Endo, Masaki; Sanada, Naoyuki; Sakurada, Shinya

    2015-05-01

    In this study, we investigated intermediate-heat treatment (IHT) at temperatures between those of sintering and solution treatment, and evaluated the effects on the macrostructure, microstructure, and magnetic properties of Sm(Cobal.Fe0.35Cu0.06Zr0.018)7.8. We found that squareness was clearly improved by adopting the IHT, which promotes grain growth. These results indicate that reducing the fraction of grain boundaries by increasing the grain size affects the behavior of domain-wall motion. Magnetic properties of Mr 1.22 T, HcJ 1580 kA/m, and (BH)max 282 kJ/m3 (>35 MGOe) were obtained for Sm(Cobal.Fe0.35Cu0.06Zr0.018)7.8 subjected to IHT at 1453 K.

  17. Ores and Climate Change - Primary Shareholders

    NASA Astrophysics Data System (ADS)

    Stein, Holly J.; Hannah, Judith L.

    2015-04-01

    Many in the economic geology community concern themselves with details of ore formation at the deposit scale, whether tallying fluid inclusion data to get at changes in ore-forming fluids or defining structures that aid and abet mineralization. These compilations are generally aimed at interpretation of events at the site of ore formation, with the goal being assignment of the deposit to a sanctioned ore deposit model. While providing useful data, this approach is incomplete and does not, by itself, serve present-day requirements for true interdisciplinary science. The ore-forming environment is one of chaos and disequilibrium at nearly all scales (Stein, 2014). Chaos and complexity are documented by variably altered rocks, veins or disseminated mineralization with multi-generational fluid histories, erratic and unusual textures in host rocks, and the bitumen or other hydrocarbon products entwined within many ore deposits. This should give pause to our drive for more data as a means to find "the answer". The answer lies in the kind of data collected and more importantly, in the way we interpret those data. Rather than constructing an ever-increasing catalog of descriptive mutations on sanctioned ore deposit models (e.g., IOGC or Iron-Oxide Copper Gold deposits), the way forward is to link source and transport of metals, sulfur, and organic material with regional and ultimately whole Earth chemical evolution. Important experimental work provides chemical constraints in controlled and behaved environments. To these data, we add imagination and interpretation, always tying back to field observations. In this paper, several key points are made by way of ore deposit examples: (1) many IOCG deposits are outcomes of profound changes in the chemistry of the Earth's surface, in the interplay of the atmosphere, hydrosphere, biosphere, and lithosphere; (2) the redox history of Fe in deep earth may be ultimately expressed in the ore-forming sequence; and (3) the formation of many giant Cu-Mo-Au ore deposits may be arrested when the surface is catastrophically breached, as multiple km-scale breccia pipes empty their volatile and metal contents into the atmosphere. The new equation for studying ore geology should be one that reconstructs ore formation from beginning to end, that is, from source, release, and transport, to breach. Of course, detailed measurements and mapping of ore bodies remains essential, but a full understanding of metal migration and budgets can only be achieved if we model what might have been left behind in deeper Earth, and what may have been lost to the atmosphere. To do this, we need to understand much more than the geology at our ore deposit of interest. Stein, H.J. (2014) Dating and Tracing the History of Ore Formation. Treatise on Geochemistry 13: 87-118. Elsevier. Support for time to think - CHRONOS, funded by a consortium of Norwegian petroleum companies.

  18. The connection between iron ore formations and "mud-shrimp" colonizations around sunken wood debris and hydrothermal sediments in a Lower Cretaceous continental rift basin, Mecsek Mts., Hungary

    NASA Astrophysics Data System (ADS)

    Jáger, Viktor; Molnár, Ferenc; Buchs, David; Kod?ra, Peter

    2012-09-01

    In the Early Cretaceous, the continental rift basin of the Mecsek Mts. (Hungary), was situated on the southern edge of the European plate. The opening of the North Atlantic Ocean created a dilatational regime that expanded to the southern edge of the European plate, where several extensional basins and submarine volcanoes were formed during the Early Cretaceous epoch. Permanent seaquake activity caused high swell events during which a large amount of terrestrial wood fragments entered into submarine canyons from rivers or suspended woods which had sunk into the deep seafloor. These fragments created extended wood-fall deposits which contributed large-scale flourishing of numerous burrowing thalassinid crustaceans. Twelve different thalassinid coprolite ichnospecies can be found in the Berriasian-Hauterivian volcano-sedimentary formations. According to the seladonitic crustacean burrows which associated with framboidal pyrite containing Zoophycos and Chondrites ichnofossils (i.e. a "fodinichnia" trace fossil association), the bottom water was aerobic and the pore water was anaerobic; in the latter sulfate reduction occurred. The preservation of wood fragments around thalassinid burrows can be explained by rapid sedimentation related to turbidity currents. Due to the low temperature hydrothermal circulations of seawater, large amounts of iron were released from intrusive, pillowed basaltic sills; these sills intruded into soft, water-saturated sediments containing large amounts of thalassinid excrement. In the coprolites can be found idiomorphic mineral particles originating from the basalts, and coprolites can often be found in peperitic interpillow sediments. This indicates that the life-activity of the decapoda crustaceans in many Lower Cretaceous occurrences initially preceded the first magmatic eruptions. The paroxysm of the rift volcanism took place during the Valanginian age, when some submarine volcanoes emerged above sea level, reaching a maximum height of 300 m (above sea level); from these volcanoes further terrestrial plant debris got into the basin. Hydrothermal vents, which periodically occurred around basaltic bodies until the Hauterivian, could have contributed to the creation of favourable temperature or nutritional conditions for some decapoda crustaceans - e.g the recently described new callianassid (Nihonotrypaea thermophila), which is known only from hydrothermally infuenced habitats. Around the intrusive pillow basalts, hydrothermal circulation of oxygenated seawater occured and thick seladonitic and goethitic fills formed along the cracks and cavities of pillowed basalts. When oxidized, sulfate-rich fluids passed into the crustacean coprolite-rich, reductive and anaerobic interpillow sediments, these fluids underwent an intensive sulfate reduction. This was primarily due to termophil sulfate reducers which as proved by the negative sulfur isotope values (- 35.9‰ and - 28.0‰ ? 34S) of sulfidic hydrothermal chimneys which contain framboidal pyrite and which were formed between the pillow basalts. The largest chimney structure reached a height of 1 m, with a mass of about 150 kg. The sulfide phase is characterized by Mo enrichments up to 511 ppm. The fluid inclusion measurements from the calcitic precipitations of the sulfide chimneys indicate low temperature (~ 129 °C) hydrothermal activity, and the salinity of the primary fluid inclusions proves the seawater origin of the hydrothermal fluids. In some thalassinid crustacean coprolite rich interpillow sediments and in the cracks of some hydrothermal calcite, there is the presence of black, lustrous bitumine (gilsonite) which is the distillation product of hydrothermal petroleum formed mainly by the coprolites. Hydrothermal circulations of oxygenated seawater caused subsequent oxidation of the sulfidic, interpillow sediments and chimneys; these were altered to form goethite. Due to the short-period of the hydrothermal activity among the intrusive pillowed basalts, sulfidized interpillow sediments could not be oxidized completely. The text

  19. Limonite Pile at Saugus Iron Works

    USGS Multimedia Gallery

    A pile of limonite rocks used in the iron smelting process. Limonite is a well-known iron ore that has been mined for iron for many thousands of years. At the Saugus Iron Works, the limonite was found in nearby bogs....

  20. The Saugus Iron Works Blast Furnace

    USGS Multimedia Gallery

    A view of the Saugus Iron Works blast furnace, which smelted the iron from limonite, an iron ore. The limonite formed in nearby bogs, and was heated in the blast furnace until the iron melted and ran out the bottom of the furnace. ...

  1. In vitro study on newly designed biodegradable Fe-X composites (X W, CNT) prepared by spark plasma sintering

    E-print Network

    Zheng, Yufeng

    iron and the additive secondary phase X using the spark plasma sintering (SPS) method, aiming to obtain on newly designed biodegradable Fe-X composites (X ¼ W, CNT) prepared by spark plasma sintering. J Biomed plasma sintering J. Cheng,1 Y.F. Zheng1,2 1 Center for Biomedical Materials and Tissue Engineering

  2. 26. NORTHERN VIEW OF ORE YARD WITH ORE BRIDGES IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. NORTHERN VIEW OF ORE YARD WITH ORE BRIDGES IN THE BACKGROUND. BLAST FURNACES ALONG THE RIGHT SIDE. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  3. Introduction to ore geology

    SciTech Connect

    Evans, A.M.

    1987-01-01

    This textbook on ore geology is for second and third year undergraduates and closely parallels the undergraduate course given in this subject at England's University of Leicester. The volume covers three major areas: (1) principles of ore geology, (2) examples of the most important types of ore deposits, and (3) mineralization in space and time. Many chapters have been thoroughly revised for this edition and a chapter on diamonds has been added. Chapters on greisen and pegmatite have also been added, the former in response to the changing situation in tin mining following the recent tin crisis, and the latter in response to suggestions from geologists in a number of overseas countries. Some chapters have been considerably expanded and new sections added, including disseminated gold deposits and unconformity-associated uranium deposits. The author also expands on the importance of viewing mineral deposits from an economic standpoint.

  4. 14. HULETT ORE UNLOADERS IN MOTION; UNLOADING CANADIAN RED ORE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. HULETT ORE UNLOADERS IN MOTION; UNLOADING CANADIAN RED ORE FROM THE 'GEORGE M. CAR.' VIEW LOOKING EAST. (Also see OH-18-38, OH-18-39, and OH-18-40.) - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  5. 38. HULETT ORE UNLOADERS IN MOTION; UNLOADING CANADIAN RED ORE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. HULETT ORE UNLOADERS IN MOTION; UNLOADING CANADIAN RED ORE FROM THE GEORGE M. CARL.' VIEW LOOKING EAST. (Also see OH-18-14, OH-18-39, and OH-18-40) - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  6. Extraction of copper from an oxidized (lateritic) ore using bacterially catalysed reductive dissolution.

    PubMed

    Nancucheo, Ivan; Grail, Barry M; Hilario, Felipe; du Plessis, Chris; Johnson, D Barrie

    2014-01-01

    An oxidized lateritic ore which contained 0.8 % (by weight) copper was bioleached in pH- and temperature-controlled stirred reactors under acidic reducing conditions using pure and mixed cultures of the acidophilic chemolithotrophic bacterium Acidithiobacillus ferrooxidans. Sulfur was provided as the electron donor for the bacteria, and ferric iron present in goethite (the major ferric iron mineral present in the ore) acted as electron acceptor. Significantly more copper was leached by bacterially catalysed reductive dissolution of the laterite than in aerobic cultures or in sterile anoxic reactors, with up to 78 % of the copper present in the ore being extracted. This included copper that was leached from acid-labile minerals (chiefly copper silicates) and that which was associated with ferric iron minerals in the lateritic ore. In the anaerobic bioreactors, soluble iron in the leach liquors was present as iron (II) and copper as copper (I), but both metals were rapidly oxidized (to iron (III) and copper (II)) when the reactors were aerated. The number of bacteria added to the reactors had a critical role in dictating the rate and yield of copper solubilised from the ore. This work has provided further evidence that reductive bioprocessing, a recently described approach for extracting base metals from oxidized deposits, has the potential to greatly extend the range of metal ores that can be biomined. PMID:24687752

  7. Sintering titanium powders

    SciTech Connect

    Gerdemann, Stephen J.; Alman, David E.

    2005-09-01

    Recently, there has been renewed interest in low-cost titanium. Near-net-shape powder metallurgy offers the potential of manufacturing titanium articles without costly and difficult forming and machining operations; hence, processing methods such as conventional press-and-sinter, powder forging and powder injection molding are of interest. The sintering behavior of a variety of commercial and experimental titanium powders was studied. Commercial powders were acquired that were produced different routes: (i) sponge fines from the primary titanium processing; (ii) via the hydride-dehydride process; and (iii) gas atomization. The influence of vacuum sintering time (0.5 to 32 hrs) and temperature (1200, 1275 or 1350°C) on the microstructure (porosity present) of cold pressed powders was studied. The results are discussed in terms of the difference in powder characteristics, with the aim of identify the characteristics required for full density via press-and-sinter processing. Near-net-shape tensile bars were consolidated via cold pressed and sintered. After sintering, a sub-set of the tensile bars was hot-isostatic pressed (HIPed). The microstructure and properties of the bars were compared in the sintered and HIPed conditions.

  8. Microwave sintering of ceramics

    SciTech Connect

    Snyder, W.B.

    1989-01-01

    Successful adaptation of microwave heating to the densification of ceramic materials require a marriage of microwave and materials technologies. Using an interdisciplinary team of microwave and materials engineers, we have successfully demonstrated the ability to density ceramic materials over a wide range of temperatures. Microstructural evolution during microwave sintering has been found to be significantly different from that observed in conventional sintering. Our results and those of others indicate that microwave sintering has the potential to fabricate components to near net shape with mechanical properties equivalent to hot pressed or hot isostatically pressed material. 6 refs., 11 figs.

  9. Bioprocessing of ores: Application to space resources

    NASA Technical Reports Server (NTRS)

    Johansson, Karl R.

    1992-01-01

    The role of microorganisms in the oxidation and leaching of various ores (especially those of copper, iron, and uranium) is well known. This role is increasingly being applied by the mining, metallurgy, and sewage industries in the bioconcentration of metal ions from natural receiving waters and from waste waters. It is concluded that bioprocessing using bacteria in closed reactors may be a variable option for the recovery of metals from the lunar regolith. Obviously, considerable research must be done to define the process, specify the appropriate bacteria, determine the necessary conditions and limitations, and evaluate the overall feasibility.

  10. 77 FR 44146 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Control of Iron and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-27

    ...Implementation Plans; Maryland; Control of Iron and Steel Production Installations; Sintering...Maryland SIP's regulation for the Control of Iron and Steel Production Installations only...section of the regulation for the Control of Iron and Steel Production Installations...

  11. 77 FR 44204 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Control of Iron and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-27

    ...Implementation Plans; Maryland; Control of Iron and Steel Production Installations; Sintering...Maryland SIP's regulation for the Control of Iron and Steel Production Installations as they...section of the regulation for the Control of Iron and Steel Production Installations...

  12. Single-Step Ironmaking from Ore to Improve Energy Efficiency

    SciTech Connect

    S.K. Kawatra; B. Anamerie; T.C. Eisele

    2005-10-01

    The pig iron nugget process was developed as an alternative to the traditional blast furnace process by Kobe Steel. The process aimed to produce pig iron nuggets, which have similar chemical and physical properties to blast furnace pig iron, in a single step. The pig iron nugget process utilizes coal instead of coke and self reducing and fluxing dried green balls instead of pellets and sinters. In this process the environmental emissions caused by coke and sinter production, and energy lost between pellet induration (heat hardening) and transportation to the blast furnace can be eliminated. The objectives of this research were to (1) produce pig iron nuggets in the laboratory, (2) characterize the pig iron nugget produced and compare them with blast furnace pig iron, (3) investigate the furnace temperature and residence time effects on the pig iron nugget production, and (4) optimize the operational furnace temperatures and residence times. The experiments involved heat treatment of self reducing and fluxing dried green balls at various furnace temperatures and residence times. Three chemically and physically different products were produced after the compete reduction of iron oxides to iron depending on the operational furnace temperatures and/or residence times. These products were direct reduced iron (DRI), transition direct reduced iron (TDRI), and pig iron nuggets. The increase in the carbon content of the system as a function of furnace temperature and/or residence time dictated the formation of these products. The direct reduced iron, transition direct reduced iron, and pig iron nuggets produced were analyzed for their chemical composition, degree of metallization, apparent density, microstructure and microhardness. In addition, the change in the carbon content of the system with the changing furnace temperature and/or residence time was detected by optical microscopy and Microhardness measurements. The sufficient carbon dissolution required for the production of pig iron nuggets was determined. It was determined that pig iron nuggets produced had a high apparent density (6.7-7.2 gr/cm3), highly metallized, slag free structure, high iron content (95-97%), high microhardness values (> 325 HVN) and microstructure similar to white cast iron. These properties made them a competitive alternative to blast furnace pig iron.

  13. The Sintering Characteristics of Mixing SiO2 with Calcium Ferrite at 1473 K (1200 °C)

    NASA Astrophysics Data System (ADS)

    Ding, Xiang; Guo, Xing-Min

    2015-08-01

    The liquid-generating capability in high basicity sinter was investigated by adding SiO2 to CaO·Fe2O3 (CF) at 1473 K (1200 °C) in air for 4 hours. X-ray diffraction, electron-probe microanalysis, and optical microscopy combining with etching test were used to characterize the phase change of sintered samples. The results show that the minor SiO2 additions from 0.14 wt pct to 6.49 wt pct to CF depressed the melting temperature of CF. New phases of formation included from SFC (silico-ferrite of calcium), SFC + Hem (Fe2O3) + CS (CaO·SiO2) to Hem + CS in samples with SiO2 additions from 0.05 wt pct to 21.74 wt pct. With the maximum SFC produced in sample, the amount of SiO2 addition was 10.64 wt pct. To understand the depressing mechanism of CF melting temperature, the experiments of differential scanning calorimetry for samples of CF, SFC, CF-SiO2 (3.0 wt pct), and CF-SFC (50.0 wt pct) had been carried out. The result shows that mixing of SiO2 or SFC with CF decreased the melting temperature of CF by 35 K and 34 K (35 °C and 34 °C), respectively, resulted in melting temperature approaching the eutectic temperature between CF and SFC. The phase relations between CF and SFC, as well as the intermediate products in depressing the melting temperature, will be an important guide to improve the sintering characteristics of iron ores.

  14. Preparation and mechanism of the sintered bricks produced from Yellow River silt and red mud.

    PubMed

    He, Hongtao; Yue, Qinyan; Su, Yuan; Gao, Baoyu; Gao, Yue; Wang, Jingzhou; Yu, Hui

    2012-02-15

    The preparation, characteristics and mechanisms of sintered bricks manufactured by Yellow River silt and red mud were studied. The sintering shrinkage, weight loss on ignition, water absorption and compressive strength were tested to determine the optimum preparation condition. Sintering mechanisms were discussed through linear regression analysis. Crystalline components of raw materials and bricks were analyzed by X-ray diffraction. Leaching toxicity of raw materials and bricks were measured according to sulphuric acid and nitric acid method. Radiation safety of the sintered bricks was characterized by calculating internal exposure index and external exposure index. The results showed that at the chosen best parameters (red mud content of 40%, sintering temperature of 1050°C and sintering time of 2h), the best characteristics of sintered bricks could be obtained. The weight loss on ignition of sintered bricks was principally caused by the removal of absorbed water and crystal water. The sintering shrinkage of sintered bricks mainly depended on sodium compounds and iron compounds of red mud. The sintering process made some components of raw materials transform into other crystals having better thermostability. Besides, the leaching toxicity and radioactivity index of sintered bricks produced under the optimum condition were all below standards. PMID:22192584

  15. Sintered wire annode

    DOEpatents

    Falce, Louis R. (Surprise, AZ); Ives, R. Lawrence (Saratoga, CA)

    2007-12-25

    A plurality of high atomic number wires are sintered together to form a porous rod that is parted into porous disks which will be used as x-ray targets. A thermally conductive material is introduced into the pores of the rod, and when a stream of electrons impinges on the sintered wire target and generates x-rays, the heat generated by the impinging x-rays is removed by the thermally conductive material interspersed in the pores of the wires.

  16. Effect of attrition milling on the reaction sintering of silicon nitride

    NASA Technical Reports Server (NTRS)

    Herbell, T. P.; Glasgow, T. K.; Yeh, H. C.

    1978-01-01

    Silicon powder was ground in a steel attrition mill under nitrogen. Air exposed powder was compacted, prefired in helium, and reaction sintered in nitrogen-4 v/o hydrogen. For longer grinding times, oxygen content, surface area and compactability of the powder increased; and both alpha/beta ratio and degreee of nitridation during sintering increased. Iron content remained constant.

  17. Effect of attrition milling on the reaction sintering of silicon nitride

    NASA Technical Reports Server (NTRS)

    Herbell, T. P.; Glasgow, T. K.; Yeh, H. C.

    1978-01-01

    Silicon powder was ground in a steel attrition mill under nitrogen. Air-exposed powder was compacted, prefired in helium, and reaction-sintered in nitrogen-4 v/o hydrogen. For longer grinding times, oxygen content, surface area and compactability of the powder increased; and both alpha/beta ratio and degree of nitridation during sintering increased. Iron content remained constant.

  18. 40 CFR 420.20 - Applicability; description of the sintering subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 29 2014-07-01 2012-07-01 true Applicability; description of the sintering subcategory. 420.20 Section 420.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Sintering Subcategory § 420.20...

  19. 40 CFR 420.20 - Applicability; description of the sintering subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Applicability; description of the sintering subcategory. 420.20 Section 420.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Sintering Subcategory § 420.20...

  20. 40 CFR 420.20 - Applicability; description of the sintering subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Applicability; description of the sintering subcategory. 420.20 Section 420.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Sintering Subcategory § 420.20...

  1. Effect of the powder characteristics of Sisub3Nsub4 on the microstructure of sintered bodies

    NASA Technical Reports Server (NTRS)

    Woetting, G.; Hausner, H.

    1981-01-01

    Silicon nitride powders sintered with the addition of 2 wt% Mg0 to 95% theoretical density after attrition milling and subsequent purification were evaluated. Preparation of the powders is described. The powder characteristics (specific surfaces, iron concentration, and oxygen content), and density, weight loss, and phase state of the sinter bodies as a function of powder preparation are presented.

  2. Possible lunar ores

    NASA Technical Reports Server (NTRS)

    Gillett, Stephen L.

    1991-01-01

    Despite the conventional wisdom that there are no lunar ores, geochemical considerations suggest that local concentrations of useful rare elements exist on the Moon in spite of its extreme dryness. The Moon underwent protracted igneous activity in its history, and certain magmatic processes can concentrate incompatible elements even if anhydrous. Such processes include: (1) separation of a magma into immiscible liquid phases (depending on composition, these could be silicate-silicate, silicate-oxide, silicate-sulfide, or silicate-salt); (2) cumulate deposits in layered igneous intrusions; and (3) concentrations of rare, refractory, lithophile elements (e.g., Be, Li, Zr) in highly differentiated, silica-rich magmas, as in the lunar granites. Terrestrial mining experience indicates that the single most important characteristic of a potential ore is its concentration of the desire element. The utility of a planet as a resource base is that the welter of interacting processes over geologic time can concentrate rare element automatically. This advantage is squandered if adequate exploration for ores is not first carried out.

  3. Management of solid wastes in the iron and steel industry

    SciTech Connect

    El-Gohary, F.; El-khouly, M.S.

    1983-03-01

    Wastes from a local iron and steel factory operations are agglomeration of iron ore and sintering, pig iron manufacture, steel making, rolling mill operations, and pickling. Liquid slag, produced in the blast furnace, is granulated in water and used as a concrete additive. Other wastes are directed separately to sedimentation tanks. The settleable solids are reused, and the treated effluents are pumped to a cooling tower for recycling. As a result of the new manufacturing expansion, existing waste treatment facilities are not adequate, and it was found necessary to provide additional treatment techniques. Departmental, as well as composite wastes were treated using plain sedimentation, centrifugal sedimentation, or chemical coagulation, or a combination of these methods. The results obtained showed that the use of the hydrocyclone for solid-liquid separation is much more efficient than plain sedimentation. When this process was followed by coagulation, very promising results were obtained. The use of pickling liquor as a coagulant gave comparable results with alum and ferric chloride.

  4. ORE CONVEYANCE SYSTEM AND ADIT. LOOKING WEST. ORE FROM THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ORE CONVEYANCE SYSTEM AND ADIT. LOOKING WEST. ORE FROM THE MINES ABOVE AT THE RIDGELINE AND TO THE RIGHT WAS CONVEYED TO THIS AREA AND DUMPED INTO THE SHAFT AT CENTER. THIS SHAFT OPENS INTO THE ADIT AT BOTTOM CENTER. THERE IS ANOTHER SHAFT OPENING INTO THE ADIT JUST ABOVE THE ADIT BEHIND THE STONE WALL. THE ORE WAS LOADED INTO TRAM CARS INSIDE THE ADIT AND CONVEYED ON TRACKS TO THE TRESTLE LEADING TO THE PRIMARY ORE BIN AT THE TRAM TERMINAL. TRACKS CAN BE SEEN LEADING FROM THE ADIT AND TO THE LEFT. THE ORE WAS THEN DUMPED INTO A CHUTE AT THE END OF THE TRESTLE CARRYING IT INTO THE ORE BIN AT THE TRAM TERMINAL(SEE CHUTE ON CA-291-30). - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  5. Sintering of calcium phosphate bioceramics.

    PubMed

    Champion, E

    2013-04-01

    Calcium phosphate ceramics have become of prime importance for biological applications in the field of bone tissue engineering. This paper reviews the sintering behaviour of these bioceramics. Conventional pressureless sintering of hydroxyapatite, Ca10(PO4)6(OH)2, a reference compound, has been extensively studied. Its physico-chemistry is detailed. It can be seen as a competition between two thermally activated phenomena that proceed by solid-state diffusion of matter: densification and grain growth. Usually, the objective is to promote the first and prevent the second. Literature data are analysed from sintering maps (i.e. grain growth vs. densification). Sintering trajectories of hydroxyapatite produced by conventional pressureless sintering and non-conventional techniques, including two-step sintering, liquid phase sintering, hot pressing, hot isostatic pressing, ultrahigh pressure, microwave and spark plasma sintering, are presented. Whatever the sintering technique may be, grain growth occurs mainly during the last step of sintering, when the relative bulk density reaches 95% of the maximum value. Though often considered very advantageous, most assisted sintering techniques do not appear very superior to conventional pressureless sintering. Sintering of tricalcium phosphate or biphasic calcium phosphates is also discussed. The chemical composition of calcium phosphate influences the behaviour. Similarly, ionic substitutions in hydroxyapatite or in tricalcium phosphate create lattice defects that modify the sintering rate. Depending on their nature, they can either accelerate or slow down the sintering rate. The thermal stability of compounds at the sintering temperature must also be taken into account. Controlled atmospheres may be required to prevent thermal decomposition, and flash sintering techniques, which allow consolidation at low temperature, can be helpful. PMID:23212081

  6. Sintering of Lunar and Simulant Glass

    NASA Technical Reports Server (NTRS)

    Cooper, Bonnie L.

    2007-01-01

    Most oxygen-extraction techniques are temperature-dependent, with higher temperatures resulting in higher oxygen yield. An example is hydrogen reduction, in which the optimum process temperature is 1050 C. However, glass-rich lunar soil begins to show the effects of sintering at temperatures of 900 C or lower. Sintering welds particles together due to viscous relaxation of the glass in the sample. One approach to avoid problems related to sintering, such as difficulty in removing waste material from the reactor, is to keep the soil in motion. One of several methods being studied to accomplish this is fluidized-bed processing techniques, in which the grains are kept in motion by the action of flowing reductant gas. The spent material can be removed from the chamber while still fluidized, or the fluidizing motion can continue until the material has cooled below approx. 500 C. Until end-to-end prototypes are built that can remove the heated soil, the most practical option is to keep the bed fluidized while cooling the waste material. As ISRU technology advances, another option will become valuable, which is to intentionally sinter the material to a great enough extent that it becomes a brick. The free iron in lunar soil is magnetic, and ferromagnetic bricks can be manipulated by robotic systems using electromagnetic end effectors. Finally, if an electromagnetic field is applied to the soil while the brick is being formed, the brick itself will become a magnet. This property can be used to create self-aligning bricks or other building materials that do not require fasteners. Although sintering creates a challenge for early lunar surface systems, knowledge gained during prototype development will be valuable for the advanced lunar outpost.

  7. SinterHab

    NASA Astrophysics Data System (ADS)

    Rousek, Tomáš; Eriksson, Katarina; Doule, Ond?ej

    2012-05-01

    This project describes a design study for a core module on a Lunar South Pole outpost, constructed by 3D printing technology with the use of in-situ resources and equipped with a bio-regenerative life support system. The module would be a hybrid of deployable (CLASS II) and in-situ built (CLASS III) structures. It would combine deployable membrane structures and pre-integrated rigid elements with a sintered regolith shell for enhanced radiation and micrometeorite shielding. The closed loop ecological system would support a sustainable presence on the Moon with particular focus on research activities. The core module accommodates from four to eight people, and provides laboratories as a test bed for development of new lunar technologies directly in the environment where they will be used. SinterHab also includes an experimental garden for development of new bio-regenerative life support system elements. The project explores these various concepts from an architectural point-of-view particularly, as they constitute the building, construction and interior elements. The construction method for SinterHab is based on 3D printing by sintering of the lunar regolith. Sinterator robotics 3D printing technology proposed by NASA JPL enables construction of future generations of large lunar settlements with little imported material and the use of solar energy. The regolith is processed, placed and sintered by the Sinterator robotics system which combines the NASA ATHLETE and the Chariot remotely controlled rovers. Microwave sintering creates a rigid structure in the form of walls, vaults and other architectural elements. The interior is coated with a layer of inflatable membranes inspired by the TransHab project. The life-support system is mainly bio-regenerative and several parts of the system are intrinsically multifunctional and serve more than one purpose. The plants for food production are also an efficient part of atmosphere revitalization and water treatment. Moreover, the plants will be used as a "winter garden" for psychological and recreational purposes. The water in the revitalization system has a multifunctional use, as radiation shielding in the safe-haven habitat core. The garden module creates an artificial outdoor environment mitigating the notion of confinement on the lunar surface. Fiber optics systems and plasma lamps are used for transmission of natural and artificial light into the interior.

  8. THERMODYNAMICS AND MECHANISMS OF SINTERING

    E-print Network

    Pask, J.A.

    2011-01-01

    with normal powder compacts, their tia1 sintering behaviorsintering because of inhomogeneities in packing of powderspowder which were oxidized on heating. Schematic examples of factors causing grain boundary motions in sintering

  9. In vitro degradation and biocompatibility of FePd and FePt composites fabricated by spark plasma sintering

    E-print Network

    Zheng, Yufeng

    was much smaller than that of as-cast pure iron. The metallic elements Pd and Pt were uniformly distributed- chanical properties [10]. Iron is an essential nutrient element in human body and plays an important role rate than pure iron, Fe-5 wt.%Pd and Fe-5 wt.%Pt composites were prepared by spark plasma sintering

  10. Determination of beryllium in ores and rocks by a dilution-fluorometric method with morin

    USGS Publications Warehouse

    May, R.; Grimaldi, F.S.

    1961-01-01

    Beryllium in concentrations as little as a few parts per million is determined fluorometrically with morin in low grade ores by a dilution method without separations. A high sensitivity is obtained by the adoption of instrumental and reaction conditions that give a satisfactory ratio of beryllium to blank fluorescence and at the same time minimize iron interference. Data on the behavior of 47 ions are given. The method is applied to ores containing bertrandite and beryl as the beryllium minerals.

  11. Iron deposits in relation to magmatism in China

    NASA Astrophysics Data System (ADS)

    Zhang, Zhaochong; Santosh, M.; Li, Jianwei

    2015-12-01

    China has a rich reserve of iron ores, and hosts most of the major types of iron deposits recognized over the world. However, most of these deposits are low-grade ores (<50% Fe), and the high-grade iron ores only account for ?1% of the total iron ore resources (Zhang et al., 2014a). During 50s to 70s of the last century, two major research and exploration programmes were implemented on national level in China, focusing on the high-grade iron ores of banded iron formation (BIF) deposits. However, apart from several small deposits, no large high-grade iron deposits under the BIF category were discovered. Thus, the exploration and scientific studies on iron deposits came to a dead-end during 1980's to 2005. In the recent years, however, there has been an increasing demand for iron resources due to China's rapid industrialization and economic development. Thus, a new surge of studies and prospecting of high-grade iron deposits started, which resulted in many advances in our understanding of the formation and exploration of iron deposits.

  12. Sintered wire cathode

    DOEpatents

    Falce, Louis R. (San Jose, CA); Ives, R. Lawrence (Saratoga, CA)

    2009-06-09

    A porous cathode structure is fabricated from a plurality of wires which are placed in proximity to each other in elevated temperature and pressure for a sintering time. The sintering process produces the porous cathode structure which may be divided into a plurality of individual porous cathodes, one of which may be placed into a dispenser cathode support which includes a cavity for containing a work function reduction material such as BaO, CaO, and Al.sub.2O.sub.3. The work function reduction material migrates through the pores of the porous cathode from a work replenishment surface adjacent to the cavity of the dispenser cathode support to an emitting cathode surface, thereby providing a dispenser cathode which has a uniform work function and therefore a uniform electron emission.

  13. Sintered composite filter

    DOEpatents

    Bergman, W.

    1986-05-02

    A particulate filter medium formed of a sintered composite of 0.5 micron diameter quartz fibers and 2 micron diameter stainless steel fibers is described. Preferred composition is about 40 vol.% quartz and about 60 vol.% stainless steel fibers. The media is sintered at about 1100/sup 0/C to bond the stainless steel fibers into a cage network which holds the quartz fibers. High filter efficiency and low flow resistance are provided by the smaller quartz fibers. High strength is provided by the stainless steel fibers. The resulting media has a high efficiency and low pressure drop similar to the standard HEPA media, with tensile strength at least four times greater, and a maximum operating temperature of about 550/sup 0/C. The invention also includes methods to form the composite media and a HEPA filter utilizing the composite media. The filter media can be used to filter particles in both liquids and gases.

  14. Application of Concentration-Number and Concentration-Volume Fractal Models to Recognize Mineralized Zones in North Anomaly Iron Ore Deposit, Central Iran / Zastosowanie Modeli Fraktalnych Typu K-L (Koncentracja-Liczba), Oraz K-O (Koncentracja Obj?to??) Do Rozpoznawania Stref Wyst?powania Surowców Mineralnych W Regionie Z?ó? Rud ?elaza North Anomaly, W ?rodkowym Iranie

    NASA Astrophysics Data System (ADS)

    Afzal, Peyman; Ghasempour, Reza; Mokhtari, Ahmad Reza; Haroni, Hooshang Asadi

    2015-09-01

    Identification of various mineralized zones in an ore deposit is essential for mine planning and design. This study aims to distinguish the different mineralized zones and the wall rock in the Central block of North Anomaly iron ore deposit situated in Bafq (Central Iran) utilizing the concentration-number (C-N) and concentration-volume (C-V) fractal models. The C-N model indicates four mineralized zones described by Fe thresholds of 8%, 21%, and 50%, with zones <8% and >50% Fe representing wall rocks and highly mineralized zone, respectively. The C-V model reveals geochemical zones defined by Fe thresholds of 12%, 21%, 43% and 57%, with zones <12% Fe demonstrating wall rocks. Both the C-N and C-V models show that highly mineralized zones are situated in the central and western parts of the ore deposit. The results of validation of the fractal models with the geological model show that the C-N fractal model of highly mineralized zones is better than the C-V fractal model of highly mineralized zones based on logratio matrix. Identyfikacja stref wyst?powania surowców mineralnych jest kwestia kluczow? przy planowaniu wydobycia i projektowaniu kopalni. Celem pracy jest rozró?nienie stref o ró?nej zawarto?ci surowców mineralnych oraz pasma skalnego w ?rodkowej cz??ci zag??bia Bafq (?rodkowa cze?? Iranu) przy wykorzystaniu modeli fraktalnych typu koncentracja-liczba i koncentracja-obj?to??. Model koncentracja-liczba pozwala na wyró?nienie czterech stref wyst?powania surowca, definiowanych poprzez progow? zawarto?? ?elaza w rudzie na poziomie 8%, 21%, i 50% oraz strefy <8% i >50% zawarto?ci ?elaza, co odpowiada pasmu skalnemu oraz strefie o wysokim stopniu zawarto?ci rudy. Model koncentracja-obj?to?? wskazuje na istnienie stref geochemicznych okre?lonych poprzez progowe warto?ci zawarto?ci ?elaza: 12%, 21%, 43% i 57 % oraz strefy <12%, co odpowiada ?cianie skalnej. Obydwa modele stwierdzaj? obecno?? stref o wysokim stopniu zawarto?ci surowca w ?rodkowej i zachodniej cz??ci z?o?a. Wyniki walidacji modeli fraktalnych przy u?yciu modeli geologicznych wskazuj?, ze model fraktalny koncentracja-liczba lepiej odwzorowuje obecno?? stref o wysokiej zawarto?ci rud ni? model fraktalny typu koncentracja-obj?to??.

  15. StORe Business Analysis 

    E-print Network

    Miller, Ken

    2006-12-15

    The StORe project is multidisciplinary in scope, embracing the seven scientific domains of archaeology, astronomy, biochemistry, biosciences, chemistry, physics and the social sciences (originally described in the project ...

  16. Novel Binders and Methods for Agglomeration of Ore

    SciTech Connect

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-12-31

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking. This project has identified several acid-resistant binders and agglomeration procedures that can be used for improving the energy efficiency of heap leaching, by preventing the ''ponding'' and ''channeling'' effects that currently cause reduced recovery and extended leaching cycle times. Methods have also been developed for iron ore processing which are intended to improve the performance of pellet binders, and have directly saved energy by increasing filtration rates of the pelletization feed by as much as 23%.

  17. Reactive sintering of SiC

    NASA Technical Reports Server (NTRS)

    Kim, Y. W.; Lee, J. G.

    1984-01-01

    Investigation of the sintering processes involved in the sintering of SiC revealed a connection between the types and quantities of sintering additives or catalysts and densification, initial shrinkage, and weight loss of the sintered SiC material. By sintering processes, is meant the methods of mass transport, namely solid vapor transport and grain boundary diffusion.

  18. Zone sintering of ceramic fuels

    DOEpatents

    Matthews, R. Bruce (Falls Church, VA); Chidester, Kenneth M. (Los Alamos, NM); Moore, H. Gene (Los Alamos, NM)

    1994-01-01

    Cold pressed UC.sub.2 fuel compacts are sintered at temperatures greater than about 1850.degree. C. while in contact with a sintering facilitator material, e.g., tantalum, niobium, tungsten or a metal carbide such as uranium carbide, thereby allowing for a reduction in the overall porosity and leaving the desired product, i.e., a highly dense, large-grained uranium dicarbide. The process of using the sintering facilitator materials can be applied in the preparation of other carbide materials.

  19. Upgrading Metals Via Direct Reduction from Poly-metallic Titaniferous Magnetite Ore

    NASA Astrophysics Data System (ADS)

    Samanta, Saikat; Mukherjee, Siddhartha; Dey, Rajib

    2015-02-01

    Pre-reduction is the thermo-chemical beneficiation process which is very useful technique for upgradation of metal values from complex low grade ore. The isothermal reduction behaviour of eastern Indian titaniferous magnetite lump ore without pre-treatment, pre-treated and ore-coke composite briquettes has been investigated in the present study. During pre-reduction of lump ore at 1473 K, magnetite and some part of ilmenite are transformed to metallic iron but most of the ilmenite has not reduced. Pre-treatment by multiple heating to high temperature (1373 K and 1473 K, respectively) and subsequently sudden cooling to room temperature by water successfully increase the porosity as well as many fissures in dense grain, which significantly enhance the degree of reduction. Ilmenite and magnetite phases are transformed to pseudobrookite and hematite during high temperature air soaking, and metallic iron is the dominant phase after reduction. Metallic iron and titanium dioxide are the major phases after reduction at 1373 K, but treatments above 1413 K lead to the formation of ferrous pseudobrookite (FeTi2O5). Finally, the different constitutes are separated by magnetic separation. The phases of reduced pre-treated and briquettes samples cannot be separated by magnetic separation, whereas reduced lump ore is separated successfully. The cause is perhaps due to association and interlocking of high intensity magnetic metallic iron with titanium oxide. Fe:TiO2 is upgraded about to 7.06:1 in the magnetic fraction of reduced lump ore which is formerly 2.14:1 in the case of raw ore. Vanadium is simultaneously distributed at a 3.81:1 ratio in magnetic and non-magnetic fraction.

  20. Effect of environment atmosphere on the sintering of Thai lignite fly ashes

    SciTech Connect

    Tangsathitkulchai, C.; Tangsathitkulchai, M.

    1996-12-31

    Sintering of ash particles, related to deposit formation in a pulverized coal-fired boiler, was investigated for two lignite fly ashes obtained from Mae Moh and Bangpudum coal seams. The tests involved measuring the compressive strength of cold sintered pellets at varying sintering temperature, both under oxidizing (air) and non-oxidizing atmospheres (CO{sub 2}). Under ambient air condition, Mae Moh fly ash which contained higher amount of glassy phase gave significantly higher sinter strength than Bangpudum fly ash. The role of glassy phase was confirmed by the lowering of sinter strength when HF-extracted fly ash was tested. Sintering under CO{sub 2} environment resulted in larger strength development than sintering in air. Under this non-oxidizing condition, the pellet color turned black, indicating that most of the iron was in the reduced state and could form additional low melting-point glassy phase, hence facilitated sintering rate. In addition, blending of the two ashes yielded intermediate maximum strength, under both air and CO{sub 2} environments. This observation substantiates the important role of glassy phase in the sintering process and indicates the possibility of lowering deposit strength by judicious mixing of different raw coal feeds.

  1. 2. Photocopied June 1978 'THE IRON DAM.' VIEW OF THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Photocopied June 1978 'THE IRON DAM.' VIEW OF THE IRON DAM, THE OUTCROPPING OF THE ORE FOUND IN 1826 BY HENDERSON. FURNISHED WATER TO SAWMILL. SOURCE: BENSON LOSSING, THE HUDSON, FROM THE WILDERNESS TO THE SEA, TROY, NEW YORK, 1866, p. 25 - Adirondack Iron & Steel Company, New Furnace, Hudson River, Tahawus, Essex County, NY

  2. Natural Ores as Oxygen Carriers in Chemical Looping Combustion

    SciTech Connect

    Tian, Hanjing; Siriwardane, Ranjani; Simonyi, Thomas; Poston, James

    2013-08-01

    Chemical looping combustion (CLC) is a combustion technology that utilizes oxygen from oxygen carriers (OC), such as metal oxides, instead of air to combust fuels. The use of natural minerals as oxygen carriers has advantages, such as lower cost and availability. Eight materials, based on copper or iron oxides, were selected for screening tests of CLC processes using coal and methane as fuels. Thermogravimetric experiments and bench-scale fixed-bed reactor tests were conducted to investigate the oxygen transfer capacity, reaction kinetics, and stability during cyclic reduction/oxidation reaction. Most natural minerals showed lower combustion capacity than pure CuO/Fe{sub 2}O{sub 3} due to low-concentrations of active oxide species in minerals. In coal CLC, chryscolla (Cu-based), magnetite, and limonite (Fe-based) demonstrated better reaction performances than other materials. The addition of steam improved the coal CLC performance when using natural ores because of the steam gasification of coal and the subsequent reaction of gaseous fuels with active oxide species in the natural ores. In methane CLC, chryscolla, hematite, and limonite demonstrated excellent reactivity and stability in 50-cycle thermogravimetric analysis tests. Fe{sub 2}O{sub 3}-based ores possess greater oxygen utilization but require an activation period before achieving full performance in methane CLC. Particle agglomeration issues associated with the application of natural ores in CLC processes were also studied by scanning electron microscopy (SEM).

  3. Mineral Phases and Release Behaviors of As in the Process of Sintering Residues Containing As at High Temperature

    PubMed Central

    Wang, Xingrun; Zhang, Fengsong; Nong, Zexi

    2014-01-01

    To investigate the effect of sintering temperature and sintering time on arsenic volatility and arsenic leaching in the sinter, we carried out experimental works and studied the structural changes of mineral phases and microstructure observation of the sinter at different sintering temperatures. Raw materials were shaped under the pressure of 10?MPa and sintered at 1000~1350°C for 45?min with air flow rate of 2000?mL/min. The results showed that different sintering temperatures and different sintering times had little impact on the volatilization of arsenic, and the arsenic fixed rate remained above 90%; however, both factors greatly influenced the leaching concentration of arsenic. Considering the product's environmental safety, the best sintering temperature was 1200°C and the best sintering time was 45?min. When sintering temperature was lower than 1000°C, FeAsS was oxidized into calcium, aluminum, and iron arsenide, mainly Ca3(AsO4)2 and AlAsO4, and the arsenic leaching was high. When it increased to 1200°C, arsenic was surrounded by a glass matrix and became chemically bonded inside the matrix, which lead to significantly lower arsenic leaching. PMID:24723798

  4. Anisotropy of magnetic susceptibility versus lattice-and shape-preferred orientation in the Lac Tio hemo-ilmenite ore body

    E-print Network

    Bascou, Jérôme

    Keywords: Magnetic fabric EBSD Image analysis Iron­titanium ore Anorthosite The Lac Tio hemo-ilmenite ore body crops out in the outer portion of the 1.06 Ga Lac Allard anorthosite, a member of the Havre-Saint-Pierre anorthosite suite from the Grenville province of North America. It is made up of ilmenitite (commonly

  5. Microwave sintering of multiple aritcles

    SciTech Connect

    Blake, R.D.; Katz, J.D.

    1992-12-31

    Disclosed are apparatus and method for producing articles of alumina and of alumina and silicon carbide in which the articles are sintered at high temperatures using microwave radiation. The articles are placed in a sintering container which is placed in a microwave cavity for heating. The rates at which heating and cooling take place is controlled.

  6. Microwave sintering of multiple articles

    DOEpatents

    Blake, Rodger D. (Santa Fe, NM); Katz, Joel D. (Los Alamos, NM)

    1993-01-01

    Apparatus and method for producing articles of alumina and of alumina and silicon carbide in which the articles are sintered at high temperatures using microwave radiation. The articles are placed in a sintering container which is placed in a microwave cavity for heating. The rates at which heating and cooling take place is controlled.

  7. Laser sintering of copper nanoparticles

    NASA Astrophysics Data System (ADS)

    Zenou, Michael; Ermak, Oleg; Saar, Amir; Kotler, Zvi

    2014-01-01

    Copper nanoparticle (NP) inks serve as an attractive potential replacement to silver NP inks in functional printing applications. However their tendency to rapidly oxidize has so far limited their wider use. In this work we have studied the conditions for laser sintering of Cu-NP inks in ambient conditions while avoiding oxidation. We have determined the regime for stable, low-resistivity copper (< ×3 bulk resistivity value) generation in terms of laser irradiance and exposure duration and have indicated the limits on fast processing. The role of pre-drying conditions on sintering outcome has also been studied. A method, based on spectral reflectivity measurements, was used for non-contact monitoring of the sintering process evolution. It also indicates preferred spectral regions for sintering. Finally, we illustrated how selective laser sintering can generate high-quality, fine line (<5 µm wide) and dense copper circuits.

  8. Manufacture of sintered silicon nitrides

    NASA Technical Reports Server (NTRS)

    Iwai, T.

    1985-01-01

    Sintered silicon nitrides are manufactured by sintering Si3N powder containing 2 to 15% in wt of a powder mixture composed of nitride powder of lanthanide or Y 100 parts and AIN powder less than 100 parts at 1500 to 1900 deg. temperature under a pressure of less than 200 Kg/sq. cm. The sintered Si3N has high mechanical strength in high temperature. Thus, Si3N4 93.0, Y 5.0 and AlN 2.0% in weight were wet mixed in acetone in N atom, molded and sintered at 1750 deg. and 1000 Kg/sq. cm. to give a sintered body having high hardness.

  9. Leaching of molybdenum and arsenic from uranium ore and mill tailings

    USGS Publications Warehouse

    Landa, E.R.

    1984-01-01

    A sequential, selective extraction procedure was used to assess the effects of sulfuric acid milling on the geochemical associations of molybdenum and arsenic in a uranium ore blend, and the tailings derived therefrom. The milling process removed about 21% of the molybdenum and 53% of the arsenic initially present in the ore. While about one-half of the molybdenum in the ore was water soluble, only about 14% existed in this form in the tailings. The major portion of the extractable molybdenum in the tailings appears to be associated with hydrous oxides of iron, and with alkaline earth sulfate precipitates. In contrast with the pattern seen for molybdenum, the partitioning of arsenic into the various extractable fractions differs little between the ore and the tailings. ?? 1984.

  10. Magmatic Conduit Metallogenic System - A New Model for the Origin of Ore-deposits

    NASA Astrophysics Data System (ADS)

    Su, S.; Tang, Z.; Wu, G.; Deng, J.; Xiao, Q.; Luo, Z.; Cui, Y.

    2013-12-01

    Origin and emplacement processes of ore-deposits connected with intrusions remains poorly understood. Here we propose a new model 'Magmatic Conduit Metallogenic System' to explain the origin of ore-deposits. Magmatic flow (or Melt-fluid flow) bearing metals will finally settle in the conduits at later stage of magma evolved in magma metallogenic system. Magmatic flow (or Melt-fluid flow) bearing metals include many types, such as sulfide melts and iron melts bearing fluids. Conduits will form along the zones of structural weakness, such as fault zone and interface of two different types of rocks. These conduits are usually very complicated in the magmatic system, exemplified by two typical ore-deposits, detailed as follows. The Jinchuan sulfide deposit, located in Gansu Province, China, is the third largest magmatic Cu-Ni Platinum Group Elements (PGE) in the world. There are mainly four orebodies (orebody 58, 24, 1, and 2) from west to east, with Ni/Cu value at 1.24, 1.56, 1.83 and 2.06 respectively; the content of Pt+Pd ranges from 0.4 to 10.3 ppm, with the highest value occurs in the west. This suggests that the direction of the melt flow bearing sulfide is from west to east and the front of the conduit system is in the east part of the deposit. Sulfide segregation in the magmatic chamber or in the conduits might have caused ore content to change in different part of the conduit systems. Another typical example is the Xishimen iron deposit, which is located in the South of Hebei Province, China. It has been considered as a skarn-type iron deposit conventionally. However, many geological evidence suggests that Xishimen iron deposit is a magmatic iron deposit instead. Such evidence includes: 1. The boundaries between iron orebodies and country rocks are obvious, no transitional relationship; 2. Iron ore body injected into the country rocks (including genesis, diorite, and marble); 3. There are some vesicular in the iron ores; 4. Magnetite as an interstitial mineral occurs among the pyroxenes/amphiboles. The content of titanium in the iron ores changes from 0.14% to 0.20 wt. % gradually from southeast to northwest (NW), suggesting the direction of melt-fluid flow bearing iron is from SE to NW. These characteristics in the Xishimen iron deposit indicate that melt-fluid flow bearing iron controls the distribution of iron orebodies. Several key points in 'Magmatic Conduit Metallogenic System' are concluded here: 1. All melt or melt-fluid bearing metals formed in the staging chamber are finally settled in the conduits based on their differences in density; 2. We can determine the direction of the melt or melt-fluid flow according to the content and textures of ores in the conduits. We propose that 'Magmatic Conduit Metallogenic System' could serve as a new exploring model for the ore-deposits connected with intrusions.

  11. Bog iron formation in the Nassawango Creek watershed, Maryland, USA

    USGS Publications Warehouse

    Bricker, O.P.; Newell, W.L.; Simon, N.S.

    2004-01-01

    The Nassawango bog ores in the modern environment for surficial geochemical processes were studied. The formation of Nassawango bog ores was suggested to be due to inorganic oxidation when groundwater rich in ferrous iron emerges into the oxic, surficial environment. It was suggested that the process, providing a phosphorus sink, may be an unrecognized benefit for mitigating nutrient loading from agricultural lands. It is found that without the effect of iron fixing bacteria, bog deposites could not form at significant rates.

  12. A MIXED CHEMICAL REDUCTANT FOR TREATING HEXAVALENT CHROMIUM IN A CHROMITE ORE PROCESSING SOLID WASTE

    EPA Science Inventory

    We evaluated a method for delivering ferrous iron into the subsurface to enhance chemical reduction of Cr(VI) in a chromite ore processing solid waste (COPSW). The COPSW is characterized by high pH (8.5 -11.5), high Cr(VI) concentrations in the solid phase (up to 550 mg kg-1) and...

  13. O-ring gasket test fixture

    NASA Technical Reports Server (NTRS)

    Turner, James Eric (inventor); Mccluney, Donald Scott (inventor)

    1991-01-01

    An apparatus is presented for testing O-ring gaskets under a variety of temperature, pressure, and dynamic loading conditions. Specifically, this apparatus has the ability to simulate a dynamic loading condition where the sealing surface in contact with the O-ring moves both away from and axially along the face of the O-ring.

  14. Conical O-ring seal

    DOEpatents

    Chalfant, Jr., Gordon G. (North Augusta, SC)

    1984-01-01

    A shipping container for radioactive or other hazardous materials which has a conical-shaped closure containing grooves in the conical surface thereof and an O-ring seal incorporated in each of such grooves. The closure and seal provide a much stronger, tighter and compact containment than with a conventional flanged joint.

  15. Method of processing aluminous ores

    DOEpatents

    Loutfy, Raouf O. (Naperville, IL); Keller, Rudolf (Murrysville, PA); Yao, Neng-Ping (Clarendon Hills, IL)

    1981-01-01

    A method of producing aluminum chloride from aluminous materials containing compounds of iron, titanium and silicon comprising reacting the aluminous materials with carbon and a chlorine-containing gas at a temperature of about 900.degree. K. to form a gaseous mixture containing chlorides of aluminum, iron, titanium and silicon and oxides of carbon; cooling the gaseous mixture to a temperature of about 400.degree. K. or lower to condense the aluminum chlorides and iron chlorides while titanium chloride and silicon chloride remain in the gas phase to effect a separation thereof; heating the mixture of iron chlorides and aluminum chlorides to a temperature of about 800.degree. K. to form gaseous aluminum chlorides and iron chlorides; passing the heated gases into intimate contact with aluminum sulfide to precipitate solid iron sulfide and to form additional gaseous aluminum chlorides; and separating the gaseous aluminum chloride from the solid iron sulfide.

  16. PHASE II CALDERON PROCESS TO PRODUCE DIRECT REDUCED IRON RESEARCH AND DEVELOPMENT PROJECT

    SciTech Connect

    Albert Calderon

    2005-10-14

    The commercialization path of the Calderon technology for making a feedstock for steelmaking with assistance from DOE initially focused on making coke and work was done which proved that the Calderon technology is capable of making good coke for hard driving blast furnaces. U.S. Steel which participated in such demonstration felt that the Calderon technology would be more meaningful in lowering the costs of making steel by adapting it to the making of iron--thus obviating the need for coke. U.S. Steel and Calderon teamed up to jointly work together to demonstrate that the Calderon technology will produce in a closed system iron units from iron concentrate (ore) and coal competitively by eliminating pelletizing, sintering, coking and blast furnace operation. If such process steps could be eliminated, a huge reduction in polluting emissions and greenhouse gases (including CO{sub 2}) relating to steelmaking would ensue. Such reduction will restructure the steel industry away from the very energy-intensive steelmaking steps currently practiced and drastically reduce costs of making steel. The development of a technology to lower U.S. steelmaking costs and become globally competitive is a priority of major importance. Therefore, the development work which Calderon is conducting presently under this Agreement with the U.S. Department of Energy becomes more crucial than ever. During the 3rd quarter of 2005 which the present report covers, virtually all the effort to advance the Calderon technology to make iron units was concentrated towards forming a team with a steelmaker who needs both iron units in the form of hot metal and a substitute for natural gas (SNG), both being major contributors to higher costs in steelmaking. Calderon felt that a very good candidate would be Steel Dynamics (SDI) by virtue that it operates a rotary hearth facility in Butler, Indiana that uses large amounts of natural gas to reduce briquettes made from ore and coal that they subsequently melt in a submerged arc furnace that is a large consumer of electric power. This facility is operated as a division of SDI under the name of Iron Dynamics (IDI). It is no secret that IDI has had and still has a great number of operational problems, including high cost for natural gas.

  17. Ceramic powder for sintering materials

    NASA Technical Reports Server (NTRS)

    Akiya, H.; Saito, A.

    1984-01-01

    Surface activity of ceramic powders such as MgO and Al2O3, for use in sintering with sp. emphasis on their particle size, shape, particle size distribution, packing, and coexisting additives and impurities are reviewed.

  18. The sintering of nitrogen ceramics

    SciTech Connect

    Hampshire, S.

    1986-01-01

    The mechanism of densification with oxide additives and the role of the ..cap alpha..-BETA phase transformation is investigated in a detailed kinetic study. Selected compositions in the Si-Al-O-N system are detailed, with and without additives. Although the work is mainly concerned with the identification of the mechanisms of sintering, some property measurements on a sintered BETA-sialon are reported and the feasibility of preparing pure ..cap alpha..-sialon phases is explored.

  19. PLANETESIMAL FORMATION INDUCED BY SINTERING

    SciTech Connect

    Sirono, Sin-iti

    2011-06-01

    Sintering of H{sub 2}O ice proceeds in an icy dust aggregate as the temperature increases due to the infall to the central star. By numerical simulations, I show that fragmentation of the aggregate by sintering occurs at a particular region of a protoplanetary nebula. The fragments accumulate at the region because their infalling velocity is low. The dust surface density exceeds the critical surface density required for gravitational instability to form planetesimals.

  20. Method of sintering ceramic materials

    DOEpatents

    Holcombe, C.E.; Dykes, N.L.

    1992-11-17

    A method for sintering ceramic materials is described. A ceramic article is coated with layers of protective coatings such as boron nitride, graphite foil, and niobium. The coated ceramic article is embedded in a container containing refractory metal oxide granules and placed within a microwave oven. The ceramic article is heated by microwave energy to a temperature sufficient to sinter the ceramic article to form a densified ceramic article having a density equal to or greater than 90% of theoretical density. 2 figs.

  1. Method of sintering ceramic materials

    DOEpatents

    Holcombe, Cressie E. (Knoxville, TN); Dykes, Norman L. (Oak Ridge, TN)

    1992-01-01

    A method for sintering ceramic materials is described. A ceramic article is coated with layers of protective coatings such as boron nitride, graphite foil, and niobium. The coated ceramic article is embedded in a container containing refractory metal oxide granules and placed within a microwave oven. The ceramic article is heated by microwave energy to a temperature sufficient to sinter the ceramic article to form a densified ceramic article having a density equal to or greater than 90% of theoretical density.

  2. Viscous sintering of volcanic ash

    NASA Astrophysics Data System (ADS)

    Wadsworth, F. B.; Scheu, B.; Vasseur, J.; Tuffen, H.; von Aulock, F. W.; Lavallée, Y.; Hess, K. U.; Dingwell, D. B.

    2014-12-01

    Volcanic ash is often deposited in a hot state. Volcanic ash containing glass, deposited above the glass transition interval, has the potential to sinter viscously both to itself (particle-particle) and to exposed surfaces. Here, we constrain the kinetics of this process experimentally under isothermal and non-isothermal conditions using standard glasses and volcanic ash. In the absence of external load, this process is dominantly driven by surface relaxation. In such cases the sintering process is rate-limited by the melt viscosity, the size of the particles and the melt-vapour interfacial tension. We propose a polydisperse continuum model that describes the transition from a packing of particles to a dense pore-free melt and evaluate its efficacy in describing the kinetics of volcanic viscous sintering. We apply our model to viscous sintering scenarios for cooling crystal-poor rhyolitic ash using the 2008 eruption of Chaitén volcano as a case example. We predict that moderate cooling rates result in the common observation of incomplete sintering and the preservation of pore networks. Finally we discuss the effect of crystallisation, external loading and volatile degassing or regassing during viscous sintering and assert that such complexities must be considered in the volcanic scenario.

  3. Iron Test

    MedlinePLUS

    ... detect and help diagnose iron deficiency or iron overload. In people with anemia , these tests can help ... also be ordered when iron deficiency or iron overload is suspected. Early iron deficiency often goes unnoticed. ...

  4. Effect of desliming on the magnetic separation of low-grade ferruginous manganese ore

    NASA Astrophysics Data System (ADS)

    Tripathy, Sunil Kumar; Banerjee, P. K.; Suresh, Nikkam

    2015-07-01

    In the present investigation, magnetic separation studies using an induced roll magnetic separator were conducted to beneficiate low-grade ferruginous manganese ore. The feed ore was assayed to contain 22.4% Mn and 35.9% SiO2, with a manganese-to-iron mass ratio (Mn:Fe ratio) of 1.6. This ore was characterized in detail using different techniques, including quantitative evaluation of minerals by scanning electron microscopy, which revealed that the ore is extremely siliceous in nature and that the associated gangue minerals are more or less evenly distributed in almost all of the size fractions in major proportion. Magnetic separation studies were conducted on both the as-received ore fines and the classified fines to enrich their manganese content and Mn:Fe ratio. The results indicated that the efficiency of separation for deslimed fines was better than that for the treated unclassified bulk sample. On the basis of these results, we proposed a process flow sheet for the beneficiation of low-grade manganese ore fines using a Floatex density separator as a pre-concentrator followed by two-stage magnetic separation. The overall recovery of manganese in the final product from the proposed flow sheet is 44.7% with an assay value of 45.8% and the Mn:Fe ratio of 3.1.

  5. Sintering of lunar glass and basalt

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; Hines, Joy A.; Mckay, David S.; Morris, Richard V.

    1992-01-01

    Experiments were conducted to study the sintering behavior of glass and basalt lunar soil simulants. The degree of sintering was assessed by compressive strength testing and microanalysis. Both crushed glass and basalt sinter significantly at 1000 C, with the basalt attaining its maximum strength at 1100 C. Initial sintering occurs in less than 15 min, and the degree of sintering does not increase significantly with time after about 30 min. Glass sinters more readily than crystalline material. Sintering and devitrification both occur on a time scale of minutes in the heated glass, but sintering is apparently more rapid. The processes of sintering and oxygen release by hydrogen reduction of lunar soil are synergistic, and could be combined to produce two extremely useful products at a lunar base.

  6. Magnetization curves of sintered heavy tungsten alloys for applications in MRI-guided radiotherapy

    SciTech Connect

    Kolling, Stefan; Oborn, Bradley M.; Keall, Paul J.; Horvat, Joseph

    2014-06-15

    Purpose: Due to the current interest in MRI-guided radiotherapy, the magnetic properties of the materials commonly used in radiotherapy are becoming increasingly important. In this paper, measurement results for the magnetization (BH) curves of a range of sintered heavy tungsten alloys used in radiation shielding and collimation are presented. Methods: Sintered heavy tungsten alloys typically contain >90?% tungsten and <10?% of a combination of iron, nickel, and copper binders. Samples of eight different grades of sintered heavy tungsten alloys with varying binder content were investigated. Using a superconducting quantum interference detector magnetometer, the induced magnetic momentm was measured for each sample as a function of applied external field H{sub 0} and the BH curve derived. Results: The iron content of the alloys was found to play a dominant role, directly influencing the magnetizationM and thus the nonlinearity of the BH curve. Generally, the saturation magnetization increased with increasing iron content of the alloy. Furthermore, no measurable magnetization was found for all alloys without iron content, despite containing up to 6% of nickel. For two samples from different manufacturers but with identical quoted nominal elemental composition (95% W, 3.5% Ni, 1.5% Fe), a relative difference in the magnetization of 11%–16% was measured. Conclusions: The measured curves show that the magnetic properties of sintered heavy tungsten alloys strongly depend on the iron content, whereas the addition of nickel in the absence of iron led to no measurable effect. Since a difference in the BH curves for two samples with identical quoted nominal composition from different manufacturers was observed, measuring of the BH curve for each individual batch of heavy tungsten alloys is advisable whenever accurate knowledge of the magnetic properties is crucial. The obtained BH curves can be used in FEM simulations to predict the magnetic impact of sintered heavy tungsten alloys.

  7. Leaching of radionuclides from uranium ore and mill tailings ( Ra- 226, Tn-230).

    USGS Publications Warehouse

    Landa, E.R.

    1982-01-01

    The major part of the extractable uranium is associated with a readily acid-soluble fraction in both ore and tailings. The major part of the extractable 226Ra was associated with an iron, manganese hydrous-oxide fraction in the ore and tailings. Thorium-230 was the least leachable of the radionuclides studied. The major portion of the extractable 230Th was associated with alkaline-earth sulphate precipitates, organic matter, or both. The specific effects of milling on each of the nuclides are discussed.-Author

  8. Massive deep-sea sulphide ore deposits discovered on the East Pacific Rise

    USGS Publications Warehouse

    Francheteau, Jean; Needham, H.D.; Choukroune, P.; Juteau, Tierre; Seguret, M.; Ballard, Richard D.; Fox, P.J.; Normark, William; Carranza, A.; Cordoba, D.; Guerrero, J.; Rangin, C.; Bougault, H.; Cambon, P.; Hekinian, R.

    1979-01-01

    Massive ore-grade zinc, copper and iron sulphide deposits have been found at the axis of the East Pacific Rise. Although their presence on the deep ocean-floor had been predicted there was no supporting observational evidence. The East Pacific Rise deposits represent a modern analogue of Cyprus-type sulphide ores associated with ophiolitic rocks on land. They contain at least 29% zinc metal and 6% metallic copper. Their discovery will provide a new focus for deep-sea exploration, leading to new assessments of the concentration of metals in the upper layers of the oceanic crust. ?? 1979 Nature Publishing Group.

  9. Effects of sintering atmosphere on the physical and mechanical properties of modified BOF slag glass

    NASA Astrophysics Data System (ADS)

    Dai, Wen-bin; Li, Yu; Cang, Da-qiang; Zhou, Yuan-yuan; Fan, Yong

    2014-05-01

    This study proposes an efficient way to utilize all the chemical components of the basic oxygen furnace (BOF) slag to prepare high value-added glass-ceramics. A molten modified BOF slag was converted from the melting BOF slag by reducing it and separating out iron component in it, and the modified BOF slag was then quenched in water to form glasses with different basicities. The glasses were subsequently sintered in the temperature range of 600-1000°C in air or nitrogen atmosphere for 1 h. The effects of different atmospheres on the physical and mechanical properties of sintered samples were studied by using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM) and by conducting experiment on evaluating the sintering shrinkage, water absorption and bulk density. It is found that the kinetics of the sintering process is significantly affected by sintering atmosphere. In particular, compared with sintering in air atmosphere, sintering in N2 atmosphere promotes the synergistic growth of pyroxene and melilite crystalline phases, which can contribute to better mechanical properties and denser microstructure.

  10. Effect of processing conditions on microstructural features in Mn–Si sintered steels

    SciTech Connect

    Oro, Raquel; Hryha, Eduard; Campos, Mónica; Torralba, José M.

    2014-09-15

    Sintering of steels containing oxidation sensitive elements is possible if such elements are alloyed with others which present lower affinity for oxygen. In this work, a master alloy powder containing Fe–Mn–Si–C, specifically designed to create a liquid phase during sintering, has been used for such purpose. The effect of processing conditions such as sintering temperature and atmosphere was studied with the aim of describing the microstructural evolution as well as the morphology and distribution of oxides in the sintered material, evaluating the potential detrimental effect of such oxides on mechanical properties. Chemical analyses, metallography and fractography studies combined with X-ray photoelectron spectroscopy analyses on the fracture surfaces were used to reveal the main mechanism of fracture and their correlation with the chemical composition of the different fracture surfaces. The results indicate that the main mechanism of failure in these steels is brittle fracture in the surrounding of the original master alloy particles due to degradation of grain boundaries by the presence of oxide inclusions. Mn–Si oxide inclusions were observed on intergranular decohesive facets. The use of reducing atmospheres and high sintering temperatures reduces the amount and size of such oxide inclusions. Besides, high heating and cooling rates reduce significantly the final oxygen content in the sintered material. A model for microstructure development and oxide evolution during different stages of sintering is proposed, considering the fact that when the master alloy melts, the liquid formed can dissolve some of the oxides as well as the surface of the surrounding iron base particles. - Highlights: • Oxide distribution in steels containing oxidation-sensitive elements • Mn, Si introduced in a master alloy powder, mixed with a base iron powder • Selective oxidation of Mn and Si on iron grain boundaries • Decohesive fracture caused by degradation of grain boundaries by oxide inclusions • Reducing agents efficient at low temperatures critical for avoiding oxide inclusions.

  11. Method of making bonded or sintered permanent magnets

    DOEpatents

    McCallum, R.W.; Dennis, K.W.; Lograsso, B.K.; Anderson, I.E.

    1993-08-31

    An isotropic permanent magnet is made by mixing a thermally responsive, low viscosity binder and atomized rare earth-transition metal (e.g., iron) alloy powder having a carbon-bearing (e.g., graphite) layer thereon that facilitates wetting and bonding of the powder particles by the binder. Prior to mixing with the binder, the atomized alloy powder may be sized or classified to provide a particular particle size fraction having a grain size within a given relatively narrow range. A selected particle size fraction is mixed with the binder and the mixture is molded to a desired complex magnet shape. A molded isotropic permanent magnet is thereby formed. A sintered isotropic permanent magnet can be formed by removing the binder from the molded mixture and thereafter sintering to full density.

  12. Method of making bonded or sintered permanent magnets

    DOEpatents

    McCallum, R. William (Ames, IA); Dennis, Kevin W. (Ames, IA); Lograsso, Barbara K. (Ames, IA); Anderson, Iver E. (Ames, IA)

    1995-11-28

    An isotropic permanent magnet is made by mixing a thermally responsive, low viscosity binder and atomized rare earth-transition metal (e.g., iron) alloy powder having a carbon-bearing (e.g., graphite) layer thereon that facilitates wetting and bonding of the powder particles by the binder. Prior to mixing with the binder, the atomized alloy powder may be sized or classified to provide a particular particle size fraction having a grain size within a given relatively narrow range. A selected particle size fraction is mixed with the binder and the mixture is molded to a desired complex magnet shape. A molded isotropic permanent magnet is thereby formed. A sintered isotropic permanent magnet can be formed by removing the binder from the molded mixture and thereafter sintering to full density.

  13. Method of making bonded or sintered permanent magnets

    DOEpatents

    McCallum, R.W.; Dennis, K.W.; Lograsso, B.K.; Anderson, I.E.

    1995-11-28

    An isotropic permanent magnet is made by mixing a thermally responsive, low viscosity binder and atomized rare earth-transition metal (e.g., iron) alloy powder having a carbon-bearing (e.g., graphite) layer thereon that facilitates wetting and bonding of the powder particles by the binder. Prior to mixing with the binder, the atomized alloy powder may be sized or classified to provide a particular particle size fraction having a grain size within a given relatively narrow range. A selected particle size fraction is mixed with the binder and the mixture is molded to a desired complex magnet shape. A molded isotropic permanent magnet is thereby formed. A sintered isotropic permanent magnet can be formed by removing the binder from the molded mixture and thereafter sintering to full density. 14 figs.

  14. Softened-Stainless-Steel O-Rings

    NASA Technical Reports Server (NTRS)

    Marquis, G. A.; Waters, William I.

    1993-01-01

    In fabrication of O-ring of new type, tube of 304 stainless steel bent around mandril into circle and welded closed into ring. Ring annealed in furnace to make it soft and highly ductile. In this condition, used as crushable, deformable O-ring seal. O-ring replacements used in variety of atmospheres and temperatures, relatively inexpensive, fabricated with minimum amount of work, amenable to one-of-a-kind production, reusable, and environmentally benign.

  15. Iron versus Copper II. Principles and Applications in Bioinorganic Chemistry.

    ERIC Educational Resources Information Center

    Ochiai, Ei-Ichiro

    1986-01-01

    Discusses the differences between iron and copper. Describes various aspects of the behaviors of these two elements, including those of biological and environmental significance. Addresses the evolution of the atmosphere and sedimentary ore formation, the phylogeny of iron and copper, and some anthropological notes regarding the use of the metals.…

  16. Silicon carbide material sintered bodies manufacturing

    NASA Technical Reports Server (NTRS)

    Suzuki, K.; Shinohara, N.

    1984-01-01

    A method is described for producing a high density silicon carbide sintering substance which contains aluminum oxide. The sintering is done in CO gas atmosphere, which is kept at 2 to 20 atmospheric pressures.

  17. Theory and technology of sintering processes, thermal and thermochemical treatment

    SciTech Connect

    Dudnik, E.V.; Zuitseva, Z.A.; Shevchenko, A.V.; Lopato, L.M.

    1995-11-01

    The authors consider the effect of the starting powder characteristics (purity, grain size and shape, size distribution, sintering aids content, etc.), green compact microstructure (density and porosity distribution), and processing parameters (including temperature, exposure time, rate of heating or cooling of the medium) on sintering of ultrafine ZrO{sub 2}-based powders. They discuss various sintering techniques: hydrothermal sintering, microwave sintering, hot pressing, sinter-forging, sinter-HIP, and gas-pressure sintering.

  18. 63,65Cu NMR Method in a Local Field for Investigation of Copper Ore Concentrates

    NASA Astrophysics Data System (ADS)

    Gavrilenko, A. N.; Starykh, R. V.; Khabibullin, I. Kh.; Matukhin, V. L.

    2015-01-01

    To choose the most efficient method and ore beneficiation flow diagram, it is important to know physical and chemical properties of ore concentrates. The feasibility of application of the 63,65Cu nuclear magnetic resonance (NMR) method in a local field aimed at studying the properties of copper ore concentrates in the copper-iron-sulfur system is demonstrated. 63,65Cu NMR spectrum is measured in a local field for a copper concentrate sample and relaxation parameters (times T1 and T2) are obtained. The spectrum obtained was used to identify a mineral (chalcopyrite) contained in the concentrate. Based on the experimental data, comparative characteristics of natural chalcopyrite and beneficiated copper concentrate are given. The feasibility of application of the NMR method in a local field to explore mineral deposits is analyzed.

  19. Iron control in zinc pressure leach processes

    NASA Astrophysics Data System (ADS)

    Buban, K. R.; Collins, M. J.; Masters, I. M.

    1999-12-01

    The occurrence of zinc in sulfide ore deposits is generally accompanied by various iron minerals. Hence, even the most efficient concentrators generally produce a zinc concentrate with significant iron content. The efficient recovery of zinc metal from zinc concentrates requires the rejection of iron residue in a form that minimizes the zinc entrainment. Careful control of the iron precipitation step is important, so that the iron residue produced is amenable to efficient liquid-solid separation in order to obtain high zinc recoveries. In hydrometallurgical zinc processes, the coprecipitation of minor impurities along with iron precipitation is also important in producing zinc-sulfate solution from which high-purity zinc cathode can be electrowon. The integration of Dynatec’s zinc pressure leach process with existing roast-leach-electrowin plants employing various methods of iron rejection is briefly described in this article, along with the application of two-stage pressure leaching in stand-alone processes.

  20. Measuring Elastic Modulus of Sintered Metal

    NASA Technical Reports Server (NTRS)

    Fedors, R. F.; Eastman, A. F.

    1983-01-01

    Technique minimizes effect of substrate on thin sintered coating. Uniaxial tension test yields approximate value for elastic modulus of sintered material on thin substrate. Electrode composed of central perforated nickel plated steel sheet about 4 mils (0.1mm) thick, coated on each face by porous sintered nickel about 8 mils (0.2mm) thick.

  1. Dislocation generation during early stage sintering.

    NASA Technical Reports Server (NTRS)

    Sheehan, J. E.; Lenel, F. V.; Ansell, G. S.

    1973-01-01

    Discussion of the effects of capillarity-induced stresses on dislocations during early stage sintering. A special version of Hirth's (1963) theoretical calculation procedures modified to describe dislocation nucleation on planes meeting the sintering body's neck surface obliquely is shown to predict plastic flow at stress levels know to exist between micron size metal particles in the early stages of sintering.

  2. Sintering additives for zirconia ceramics

    SciTech Connect

    Wu, S.

    1986-01-01

    This book is an overview of sintering science and its application to zirconia materials including CaO, MgO, and Y/sub 2/O/sub 3/-CeO/sub 2/ doped materials. This book is a reference for first-time exposure to zirconia materials technology, particularly densification.

  3. Microwave sintering of boron carbide

    DOEpatents

    Blake, R.D.; Katz, J.D.; Petrovic, J.J.; Sheinberg, H.

    1988-06-10

    A method for forming boron carbide into a particular shape and densifying the green boron carbide shape. Boron carbide in powder form is pressed into a green shape and then sintered, using a microwave oven, to obtain a dense boron carbide body. Densities of greater than 95% of theoretical density have been obtained. 1 tab.

  4. SINTERING OF NASCENT CALCIUM OXIDE

    EPA Science Inventory

    The paper discusses the measurement of the sintering rate of CaO in a nitrogen atmosphere at temperatures of 700-1100 C. CaO prepared from ultrapure CaCO3 was compared with an impure CaO derived from limestone. Both materials yielded an initial surface area of 104 sq m/g. The rat...

  5. Estimating gold-ore mineralization potential within Topolninsk ore field (Gorny Altai)

    NASA Astrophysics Data System (ADS)

    Timkin, T.; Voroshilov, V.; Askanakova, O.; Cherkasova, T.; Chernyshov, A.; Korotchenko, T.

    2015-11-01

    Based on the results of ore and near-ore metasomatite composition analysis, the factors and indicators of gold-ore mineralization potential were proposed. Integration of the obtained data made it possible to outline magmatic, structural, and lithological factors, as well as direct and indirect indicators of gold-ore mineralization. Applying multidimensional analysis inherent to geochemical data, the spatial structure was investigated, as well as the potential mineralization was identified. Based on the developed and newly-identified mineralization, small (up to medium-sized) mineable gold-ore deposits in skarns characterized by complex geological setting was identified.

  6. Compositional Variability of Rutile in Hydrothermal Ore Deposits

    NASA Astrophysics Data System (ADS)

    Clark, J. R.; Williams-Jones, A. E.

    2009-05-01

    Rutile is a relatively common accessory phase in many geological environments, and although it is almost always composed dominantly of TiO2, it is also associated with a wide range of minor and trace element substitutions. The most prominent minor elements that occur in rutile are Fe, Cr, V, Nb and Ta. Like Ti, the latter two elements are essentially immobile in most non-magmatic metallic ore deposits, and their concentrations in rutile are largely influenced by precursor mineral compositions. Iron, Cr and V concentrations vary considerably in rutile hosted by ore deposits, and reflect combinations of precursor mineral composition and the bulk chemistry of the local mineralized or altered rock environment. However, in hydrothermal alteration zones, rutile compositions are clearly anomalous compared to those in unaltered host rocks, and have distinctive elemental associations and substitutions in different types of ore deposits. We have evaluated the mineral chemistry of rutile in >40 ore deposits worldwide. In general, rutile in volcanogenic massive sulfide deposits contains Sn (and locally W, Sb and/or Cu). Rutile from mesothermal and related gold deposits invariably contains W, and in some of the larger and more important deposits, also contains Sb and/or V. Tungsten-bearing detrital rutile grains from the Witwatersrand suggest that paleoplacer mineralization may have had a mesothermal/orogenic gold source. In some magmatic-hydrothermal Pd-Ni-Cu deposits, rutile contains Ni and Cu. Rutile associated with granite-related Sn deposits has strongly elevated concentrations of Sn and W, and granite-pegmatite W-Sn deposits contain rutile with these elements plus Nb and Ta. The Olympic Dam deposit hosts rutile that is enriched in W, Sn and Cu. Rutile associated with porphyry and skarn Cu and Cu-Au deposits tends to contain elevated W, Cu (and sometimes V). Although many ore deposits have well-defined and diagnostic rutile compositions, there are some compositional overlaps between mineralization types. Nevertheless, element combinations and ratios can be used to distinguish qualitatively between rutile compositions for most ore deposit types, and statistical methods can be used to provide more quantitative evaluation. Rutile occurs in significant abundance (typically 0.05 to 0.5 vol%) in most metallic ore deposits and is most plentiful in sulfidic systems where high fS2 and/or fO2 conditions stabilize rutile in the presence of minerals such as pyrite and hematite. Rutile is also persistent in weathering environments, and is likely to survive transport by glacial and fluvial processes. As a common component of heavy mineral sands, rutile is readily separable by routine magnetic, heavy liquid, and other density methods. These features, combined with the sensitive compositional variations in altered and mineralized rocks noted above, and the relative ease of analyses by routine electron microprobe methods, suggest that rutile has considerable potential as a geochemical indicator mineral for hydrothermal ore deposits, analogous to the kimberlite indicator minerals such as Cr-pyrope, magnesiochromite and picroilmenite that are used regularly in diamond exploration.

  7. Liquid phase sintering of tungsten composites in space: Results of tests performed in Texus

    NASA Astrophysics Data System (ADS)

    Ekbom, Lars B.; Eliasson, Anders

    Tungsten-nickel-iron composites are commersially fabricated from powders by liquid phase sintering. They consist of almost spherical tungsten particles in a matrix of nickel-iron-tungsten. A way to contribute to the understanding of the sintering mechanism and the mechanical properties is to study composites with a low amount of tungsten particles. Depending on the great difference in density between the particles and the matrix, this can only be done under microgravity. A primary sintering test of the tungsten composite was done in space using the Texus 10 modul. Prealloys were fabricated from metal powder mixtures, which were hot isostatic pressed. Liquid phase sintering of the two tungsten composites under microgravity has shown that the particles are evenly distributed and that no segregation occured due to convection. Despite an uneven distribution of the particles in the preformed specimens and the short melting period the patricle distribution has become even. Compared to short time sintering tests made on four alloys in the laboratory, the growth and separation of the particles was fast.

  8. Iron-rich fragments in the Yamansu iron deposit, Xinjiang, NW China: Constraints on metallogenesis

    NASA Astrophysics Data System (ADS)

    Li, Hou-Min; Ding, Jian-Hua; Zhang, Zhao-Chong; Li, Li-Xing; Chen, Jing; Yao, Tong

    2015-12-01

    Volcanic rock-hosted iron deposits are among the important iron ores in China. However, the nature of primary magma and petrogenesis associated with these iron ores remains controversial. Here, we report iron-rich fragments (IRF) from the Yamansu iron deposit in Eastern Tianshan Mountains, NW China, which occurs in association with volcanic breccia, submarine volcanic breccia and ignimbrite. The IRF is composed of five types including oligoclase-iron oxide type (OIO), oligoclase-albite-iron oxide type (OAIO), albite-iron oxide type (AIO), albite-K-feldspar-iron oxide type (AKIO) and K-feldspar-iron oxide type (KIO). These fragments display typical volcanic fabric features, such as porphyritic texture, hyalopilitic texture of the groundmass and vesicles filled by minerals to form amygdales. The feldspar phenocrysts of IRF are dominantly albite. The groundmass of IRF consists of magnetite and feldspar. The magnetite is distributed in between the feldspar laths, and together display hyalopilitic texture which could be observed only in volcanic rocks. The vesicles are filled with magnetite, feldspar, chlorite and calcite from the margin to the interior. The IRF has high Si, Al, Fe, Ca, Ti, Na and K contents and low Mg content. The average total Fe is 26 wt.%. The magnetite is mostly titanium-vanadium magnetite, with the TiO2 content ranging up to 4.86 wt.% and V2O3 content up to 3.20 wt.%. The IRF probably came from iron-rich melts and represent the products of the Fenner magma evolution. The basaltic magma evolved into the Fe-Na-rich residual melts by crystallization under low oxygen fugacity condition in a closed magma chamber after intruding into the shallow crust. The Fe-Na-rich residual melts were emplaced in hypabyssal environments or erupted generating the orebodies or providing the material source for the generation of the high-grade iron ores which were subsequently enriched by the late-stage hydrothermal fluids.

  9. Ratio maps of iron ore deposits Atlantic City district, Wyoming

    NASA Technical Reports Server (NTRS)

    Vincent, R. K.

    1973-01-01

    Preliminary results of a spectral rationing technique are shown for a region at the southern end of the Wind River Range, Wyoming. Digital ratio graymaps and analog ratio images have been produced for the test site, but ground truth is not yet available for thorough interpretation of these products. ERTS analog ratio images were found generally better than either ERTS single-channel images or high altitude aerial photos for the discrimination of vegetation from non-vegetation in the test site region. Some linear geological features smaller than the ERTS spatial resolution are seen as well in ERTS ratio and single-channel images as in high altitude aerial photography. Geochemical information appears to be extractable from ERTS data. Good preliminary quantitative agreement between ERTS-derived ratios and laboratory-derived reflectance ratios of rocks and minerals encourage plans to use lab data as training sets for a simple ratio gating logic approach to automatic recognition maps.

  10. Liquefaction of bituminous coals using disposable ore catalysts and hydrogen. Final report, February 7, 1982-July 31, 1982

    SciTech Connect

    Mathur, V.K.

    1982-09-01

    There are a number of problems associated with the production of liquid fuels from coal. The most complex is the use of commercial catalysts which are expensive, with short life, and cannot be recovered or regenerated. The objective of this study was to conduct experiments on coal hydrogenation using low cost mineral ores as disposable catalysts. Coal samples from Blacksville Mine, Pittsburgh Bed were hydrogenated using a number of ores, ore concentrates and industrial waste products as catalysts. Experiments were also conducted using a commercial catalyst (Harshaw Chemicals, 0402T) and no catalyst at all to compare the results. Since iron pyrite has been reported to be a good disposable catalyst, experiments were also conducted using pyrite individually as well as in admixture with other ores or concentrates. The liquefaction was conducted at 425/sup 0/C under 2000 psig (13,790 kPa) hydrogen pressure for a reaction time of 30 minutes using SRC-II heavy distillate as a vehicle oil. The conclusions of this study are as follows: (a) Results of liquefaction using two cycle technique showed that the catalytic activity of iron pyrite could be enhanced by adding materials like limonite, laterite or red mud. Iron pyrite in admixture with limonite ore or molybdenum oxide concentrate gave the best results among all the binary mixtures studied. (b) Iron pyrite with molybdenum oxide concentrate and cobaltic hydroxide cake (metal loading in each case the same as in Harshaw catalyst) gave results which compared favorably with those obtained using the Harshaw catalyst. It is recommended that work on this project should be continued exploring other ores and their mixtures for their catalytic activity for coal liquefaction.

  11. Gravitational Role in Liquid Phase Sintering

    NASA Technical Reports Server (NTRS)

    Upadhyaya, Anish; Iacocca, Ronald G.; German, Randall M.

    1998-01-01

    To comprehensively understand the gravitational effects on the evolution of both the microstructure and the macrostructure during liquid phase sintering, W-Ni-Fe alloys with W content varying from 35 to 98 wt.% were sintered in microgravity. Compositions that slump during ground-based sintering also distort when sintered under microgravity. In ground-based sintering, low solid content alloys distort with a typical elephant-foot profile, while in microgravity, the compacts tend to spheroidize. This study shows that microstructural segregation occurs in both ground-based as well as microgravity sintering. In ground-based experiments, because of the density difference between the solid and the liquid phase, the solid content increases from top to the bottom of the sample. In microgravity, the solid content increases from periphery to the center of the samples. This study also shows that the pores during microgravity sintering act as a stable phase and attain anomalous shapes.

  12. Application of spark plasma sintering for fabricating Nd-Fe-B composite

    NASA Astrophysics Data System (ADS)

    Sivkov, A. A.; Ivashutenko, A. S.; Lomakina, A. A.

    2015-10-01

    Constant magnets are applied in such fields as electric equipment and electric generators with fixed rotor. Rare earth metal neodymium is well known as promising material. Production of magnets by sintering three elements (neodymium, iron and boron) is one the most promising methods. But there are difficulties in choosing the right temperature for sintering and further processing. Structure and properties of the product, consisted of rare earth metals, was analyzed. X-ray analysis of the resulting product and the finished constant magnet was performed. Vickers microhardness was obtained.

  13. Determination of small amounts of molybdenum in tungsten and molybdenum ores

    USGS Publications Warehouse

    Grimaldi, F.S.; Wells, R.C.

    1943-01-01

    A rapid method has been developed for the determination of small amounts of molybdenum in tungsten and molybdenum ores. After removing iron and other major constituents the molybdenum thiocyanate color is developed in water-acetone solutions, using ammonium citrate to eliminate the interference of tungsten. Comparison is made by titrating a blank with a standard molybdenum solution. Aliquots are adjusted to deal with amounts of molybdenum ranging from 0.01 to 1.30 mg.

  14. Sintered wire cesium dispenser photocathode

    DOEpatents

    Montgomery, Eric J; Ives, R. Lawrence; Falce, Louis R

    2014-03-04

    A photoelectric cathode has a work function lowering material such as cesium placed into an enclosure which couples a thermal energy from a heater to the work function lowering material. The enclosure directs the work function lowering material in vapor form through a low diffusion layer, through a free space layer, and through a uniform porosity layer, one side of which also forms a photoelectric cathode surface. The low diffusion layer may be formed from sintered powdered metal, such as tungsten, and the uniform porosity layer may be formed from wires which are sintered together to form pores between the wires which are continuous from the a back surface to a front surface which is also the photoelectric surface.

  15. Sintered composite medium and filter

    DOEpatents

    Bergman, Werner (Pleasanton, CA)

    1987-01-01

    A particulate filter medium is formed of a sintered composite of 0.5 micron diameter quartz fibers and 2 micron diameter stainless steel fibers. A preferred composition is about 40 vol. % quartz and about 60 vol. % stainless steel fibers. The media is sintered at about 1100.degree. C. to bond the stainless steel fibers into a cage network which holds the quartz fibers. High filter efficiency and low flow resistance are provided by the smaller quartz fibers. High strength is provided by the stainless steel fibers. The resulting media has a high efficiency and low pressure drop similar to the standard HEPA media, with tensile strength at least four times greater, and a maximum operating temperature of about 550.degree. C. The invention also includes methods to form the composite media and a HEPA filter utilizing the composite media. The filter media can be used to filter particles in both liquids and gases.

  16. Non-Sintered Nickel Electrode

    DOEpatents

    Bernard, Patrick (Massy, FR); Dennig, Corinne (Asnieres sur Seine, FR); Cocciantelli, Jean-Michel (Bordeaux, FR); Alcorta, Jose (Bordeaux, FR); Coco, Isabelle (Dax, FR)

    2002-01-01

    A non-sintered nickel electrode contains a conductive support and a paste comprising an electrochemically active material containing nickel hydroxide and a binder which is a mixture of an elastomer and a crystalline polymer. The proportion of the elastomer is in the range 25% to 60% by weight of the binder and the proportion of the crystalline polymer is in the range 40% to 75% by weight of the binder.

  17. Low Temperature Sintering of PZT

    NASA Astrophysics Data System (ADS)

    Medesi, A.; Greiner, T.; Benkler, M.; Megnin, C.; Hanemann, T.

    2014-11-01

    This paper describes the fabrication and characterization of lead zirconate titanate (PZT) films fired in a liquid-phase sintering process at 900 °C in air. In detail the manufacturing of piezoelectric multilayers with internal pure silver (Tm = 961 °C) electrodes are reported. The feasibility of ten sintering aids in two different volume fractions was investigated for a commercial hard PZT powder (PIC 181, PI Ceramics) with respect to density, microstructure, mechanical behaviour, and piezoelectric properties. Li2O, Li2CO3, PbO, MnO2, V2O5, CuO, Bi2O3, the eutectic mixtures Cu2O·PbO and PbO·WO3 and the ternary system Li2CO3·Bi2O3·CuO (LBCu) have been tested as liquid phase sintering aids. The combination of PZT with LBCu showed the best results. With 5 vol.% LBCu an average relative density of 97% and a characteristic breaking strength of 77 MPa was achieved. Composition of PZT with 2 vol.% LBCu exhibits the highest averaged piezoelectrical charge constant (d33) of 181 pC/N.

  18. Prospecting For Magnetite Ore Deposits With A Innovative Sensor's of Unique Fundamentally New Magnetometer.

    NASA Astrophysics Data System (ADS)

    Emelianenko, T. I.; Tachaytdinov, R. S.; Sarichev, V. F.; Kotov, B. V.; Susoeva, G. N.

    After careful study of principles and abilities of all existing magnetmeters of all three revolutions in magnetic prospecting we have come to the conclusion that they cannot solve local guestions of the magnetic prospecting or determine centre coordinates of magnetite ore body before drilling Electromagnetism lows and achievents magnetprospectings and radioelectronics of all 20th century serve as a theoretical base of the "locator". While creating this cardinally new magnetmeter , we borrowed different things from radio-prospectors, magnetprospectors, wireless operators and combined all of them while creating the "locators''. The "locators' construction is bas ed on the "magnetic intensification" principle ,owing to which this "locators" are characterised by hight sensitiveness and ability to determine centers of even little commercial magnetite ore deposits with relatively weak magnetic anomalies. The main advantage of the "locators" over existing ones is that it can solve local questions determine centre coordinates. A remarkably simple locator construction determine direction of the on-surface measurings towards the ore body centre and gives approximate prognosis resourses before/withour/ drilling. The "locators" were worked out for the first time in history , they have 2 licences. The fundamental design and drawbacks of the existing magnetometers have been inherited from the original magnetometre dating back two or three hundred years. The developers of the existing magnetometres have all gone along the same well- beaten track of replacing the primitive sensor in the form of a piece of ore hung on a string at first by an arrow sensor and later by magnetically oriented protons and quanta, with amplification of the sensors' OUTPUT signal. Furthermore, all the existing magnetometres are imperfect in that they, lacking the directivity of the ground-level magnetic measurements, only record the overall magnetic vector field generated by all the ore bodies around the measurement point. The result is often misleading as an intense magnetic anomaly may be registered in a place where is no ore, and vice versa. Such false anomalies and maps may serve as the only guide in iron ore prospecting. The reserves' forecast based on such magnetic maps are also false as they may yield figures exceeding the actual reserves by tens or even hundreds of times. The existing magnetometres are often insufficiently sensitive and incapable of detecting small commercial processable ore bodies with a weak magnetic anomaly (less than 0.1% of the Earth's field). As regards new large iron ore deposits with strong anomalies, the probabilities of encountering them nowadays are becoming increasingly smaller. Confidence in the good performance and the advantages of the new magnetometres patented by the Magnitogorsk Iron and Steel Works is based on the following considerations: The anomalies' magnetic field is several times stronger than the magnetic field of the Earth; To cite two historical instances, the Sokolovskoye ore deposit in Kazakhstan was discovered in 1949 not by prospectors but by a civil aviation pilot, M.Surgutanov, using an ordinary airplane compass. The Kursk Magnetic Anomaly was discovered in 1778 by Professor I.Inozemtsev using a piece of ore hung on a string. The magnetometres patented by the MMK team, are based on the electromagnetism laws of Ampere, Ohm, Weber, Maxwell and Tesla. The history of magnetic prospecting can be divided into three periods, each of them preceded by a revolution of sorts. The first one occurred in 1910 when the German scientist Schmidt developed an optic mechanical magnetometre which came to be known in Russia as M-2 or "Fanzelau". The second revolution came about in 1936 with the invention by the Russian scientist A.Logachov of an AM-9L aeromagnetometre. The third revolution happened in 1953 when Pickard in the Unuted States (and Tsyrell in 1957 in the Soviet Union) invented a proton and quantum magnetometre. But, having examined the fundam

  19. 25. FRONT END LOADERS MOMENTARILY IN REPOSE IN THE ORE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. FRONT END LOADERS MOMENTARILY IN REPOSE IN THE ORE STORAGE YARD. AN ORE BRIDGE THAT FORMERLY TRANSFERRED ORE WITHIN THE STORAGE YARD WAS DESTROYED BY A BLIZZARD IN 1978. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  20. 36. ORE DOCK, LOOKING WEST. HULETT UNLOADERS AWAIT THE NEXT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. ORE DOCK, LOOKING WEST. HULETT UNLOADERS AWAIT THE NEXT ORE BOAT. BY LATE WINTER, THE ORE STORAGE YARD SEEN AT LEFT WILL BE DEPLETED. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  1. Sintered hydroxyfluorapatites. Part III: sintering and resultant mechanical properties of sintered blends of hydroxyapatite and fluorapatite.

    PubMed

    Gross, K?rlis A; Bhadang, Kinnari A

    2004-01-01

    The presence of chemically dissimilar apatites occurs widely in biological systems as a result of exposure to chemically enriched media, but also to optimize the mechanical properties. The use of mechanical blends of apatites can be used to manufacture high temperature processed fluoride containing hydroxyapatites with improved properties. Mechanical blends of fluorapatite and hydroxyapatite were produced with 0%, 20%, 40%, 60%, 80% and 100% fluorapatite. Pellets were sintered at 1150 degrees C, 1200 degrees C and 1250 degrees C and the density determined by the Archimedes method. Mechanical properties including hardness, elastic modulus and fracture toughness were measured using indentation. It was found that mechanical blends of 150 nm sized hydroxyapatite and 300 nm sized fluorapatite lead to solid solutions after sintering. The mechanical blends do not sinter as effectively as homogeneous hydroxyfluorapatite solid solutions and exhibit a minimum density at 80 wt.% fluorapatite. The hardness, elastic modulus and brittleness decreases with a higher flourapatite content, attributed primarily to a decrease in density. The higher fracture toughness for mechanical blends indicates that these materials are more crack resistant and provide a means for improving mechanical properties. PMID:14643614

  2. Project StORe: Social Science report 

    E-print Network

    Burton, Guy

    There was widespread support across the social science research community regarding the aims of the StORe Project Nearly half of social science respondents claimed that both source-to-output and out-put-to source repositories ...

  3. Project StORe: Biosciences report 

    E-print Network

    Biegon, Dagmar

    2006-09-15

    This report was written as part of the first phase of the national higher education research project StORe (Source-to-Output Repositories). The project included a large scale analysis of repository user behaviour, with ...

  4. Project StORe: Biosciences interviews 

    E-print Network

    Biegon, Dagmar

    2006-11-08

    This report was written as part of the first phase of the national higher education research project StORe (Source-to-Output Repositories). Data was acquired through a series of individual interviews which are presented ...

  5. Project StORe: Chemistry Report 

    E-print Network

    Polydoratou, Panayiota

    The StORe project (http://jiscstore.jot.com/WikiHome) is a collaboration of seven universities across the UK and the Johns Hopkins University in the USA and under funding from the Joint Information Systems Committee ...

  6. Project StORe: Biochemistry report 

    E-print Network

    Tonkin, Suzanne

    2006-01-01

    Biochemistry departments at UK universities were invited to take part in the Project StORe questionnaire. Potential sites were identified by using the list of departments submitting to the 1996 Research Assessment Exercise ...

  7. Open Scholarship 2006 StORe poster 

    E-print Network

    Pryor, Graham

    2006-01-01

    StORe is a project within the JISC digital repositories programme. It has a declared mission to enhance the value of academic research output by enabling direct interaction between source and output repositories...

  8. Project StORe: Physics Report 

    E-print Network

    Bull, Stephen

    Results are presented on the Physics Survey of Researcher Use of Repositories which constitutes the culmination of Work Package 2 (in Physics) of Project StORe (Source to Output Repositories). The data were obtained by ...

  9. On the sintering of silicon carbide

    NASA Technical Reports Server (NTRS)

    Gugel, E.

    1986-01-01

    This document deals with the sintering of silicon carbide using pressureless sintering. This technique makes it possible to sinter a primarily covalent material to usable densities up to over 98% thD without having to use a high amount of sinter additives as is the case with other non-oxide ceramic materials. The process takes place rapidly, and it is also possible to produce relatively thick-walled structural parts without major problems. This sheds more light on the true characteristics of silicon carbide in one structural part, since there is no second or nearly no second phase. Heat pressing has improved stability.

  10. The mechanical behavior of sintering powder compacts

    SciTech Connect

    Zipse, H.; Riedel, H.

    1995-09-01

    Micromechanical models for the sintering of powders are described and macroscopic constitutive equations are derived from them. While the first model can be regarded as the sintering of long wires, the second one is based on a three dimensional arrangement of grains with an open pore space in thermodynamic equilibrium. The dominating transport mechanism supporting densification and creep is assumed to be grain boundary diffusion in both cases. Results of sinter forging experiments are presented and compared to theoretical redictions. The implementation of constitutive equations into a finite element code offers the possibility of simulating the experiments as well as the sintering of ceramic components of complex shape.

  11. A REAL-TIME COAL CONTENT/ORE GRADE (C2OC) SENSOR

    SciTech Connect

    Rand Swanson

    2005-04-01

    This is the final report of a three year DOE funded project titled ''A real-time coal content/ore grade (C{sub 2}OG) sensor''. The sensor, which is based on hyperspectral imaging technology, was designed to give a machine vision assay of ore or coal. Sensors were designed and built at Resonon, Inc., and then deployed at the Stillwater Mining Company core room in southcentral Montana for analyzing platinum/palladium ore and at the Montana Tech Spectroscopy Lab for analyzing coal and other materials. The Stillwater sensor imaged 91' of core and analyzed this data for surface sulfides which are considered to be pathfinder minerals for platinum/palladium at this mine. Our results indicate that the sensor could deliver a relative ore grade provided tool markings and iron oxidation were kept to a minimum. Coal, talc, and titanium sponge samples were also imaged and analyzed for content and grade with promising results. This research has led directly to a DOE SBIR Phase II award for Resonon to develop a down-hole imaging spectrometer based on the same imaging technology used in the Stillwater core room C{sub 2}OG sensor. The Stillwater Mining Company has estimated that this type of imaging system could lead to a 10% reduction in waste rock from their mine and provide a $650,000 benefit per year. The proposed system may also lead to an additional 10% of ore tonnage, which would provide a total economic benefit of more than $3.1 million per year. If this benefit could be realized on other metal ores for which the proposed technology is suitable, the possible economic benefits to U.S. mines is over $70 million per year. In addition to these currently lost economic benefits, there are also major energy losses from mining waste rock and environmental impacts from mining, processing, and disposing of waste rock.

  12. Biomining: metal recovery from ores with microorganisms.

    PubMed

    Schippers, Axel; Hedrich, Sabrina; Vasters, Jürgen; Drobe, Malte; Sand, Wolfgang; Willscher, Sabine

    2014-01-01

    Biomining is an increasingly applied biotechnological procedure for processing of ores in the mining industry (biohydrometallurgy). Nowadays the production of copper from low-grade ores is the most important industrial application and a significant part of world copper production already originates from heap or dump/stockpile bioleaching. Conceptual differences exist between the industrial processes of bioleaching and biooxidation. Bioleaching is a conversion of an insoluble valuable metal into a soluble form by means of microorganisms. In biooxidation, on the other hand, gold is predominantly unlocked from refractory ores in large-scale stirred-tank biooxidation arrangements for further processing steps. In addition to copper and gold production, biomining is also used to produce cobalt, nickel, zinc, and uranium. Up to now, biomining has merely been used as a procedure in the processing of sulfide ores and uranium ore, but laboratory and pilot procedures already exist for the processing of silicate and oxide ores (e.g., laterites), for leaching of processing residues or mine waste dumps (mine tailings), as well as for the extraction of metals from industrial residues and waste (recycling). This chapter estimates the world production of copper, gold, and other metals by means of biomining and chemical leaching (bio-/hydrometallurgy) compared with metal production by pyrometallurgical procedures, and describes new developments in biomining. In addition, an overview is given about metal sulfide oxidizing microorganisms, fundamentals of biomining including bioleaching mechanisms and interface processes, as well as anaerobic bioleaching and bioleaching with heterotrophic microorganisms. PMID:23793914

  13. Antimony ore in the Fairbanks district, Alaska

    USGS Publications Warehouse

    Killeen, Pemberton Lewis; Mertie, John B., Jr.

    1951-01-01

    Antimony-bearing ores in the Fairbanks district, Alaska, are found principally in two areas, the extremities of which are at points 10 miles west and 23 miles northeast of Fairbanks; and one of two minor areas lies along this same trend 30 miles farther to the northeast. These areas are probably only local manifestations of mineralization that affected a much broader area and formed antimony-bearing deposits in neighboring districts, the closest of which is 50 miles away. The ores were exposed largely as a result of lode gold mining, but at two periods in the past, high prices for antimony ore warranted an independent production and about 2500 tons of stibnite ore was shipped. The sulfide deposits occupy the same fractures along which a gold-quartz mineralization of greater economic importance occurred; and both are probably genetically related to igneous rocks which intrude the schistose country rock. The sulfide is in part contemporaneous with some late-stage quartz in which it occurs as disseminated crystals; and in part the latest filling in the mineralized zones where it forms kidney-shaped masses of essentially solid sulfide. One extremely long mass must have contained nearly 100 tons of ore, but the average of the larger kidneys is closer to several tons. Much of the ore is stibnite, with quartz as a minor impurity, and assays show the tenor to vary from 40 to 65 percent antimony. Sulphantimonites are less abundant but likewise occur as disseminated crystals and as kidney-shaped bodies. Antimony oxides appear on the weathered surface and along fractures within the sulfide ore. Deposits containing either stibnite or sulphantimonite are known at more than 50 localities, but only eighteen have produced ore and the bulk of this came from the mines. The geology of the deposit, and the nature, extent, and period of the workings are covered in the detailed descriptions of individual occurrences. Several geologic and economic factors, which greatly affect prospecting and mining for stibnite ore in the area, are outlined. The principal available ore and reserves are considered to be ores earlier mined but never shipped, ore minable from near-surface deposits, and ores recoverable as a by-product of future gold mining. The outlook for stibnite production in the district is very uncertain. Apparently the greater portion of stibnite ore has already been recovered and present operations will strip the two principal areas of the district. This conclusion is based on the scanty discoveries since the last war and the fact that the areas are so pock-marked with prospects that there is little likelihood that any other large near-surface bodies remain to be discovered. Future prospecting would essentially be limited to attempts to seek the continuation of lodes previously having high yields of stibnite.

  14. Method of sintering materials with microwave radiation

    DOEpatents

    Kimrey, H.D. Jr.; Holcombe, C.E. Jr.; Dykes, N.L.

    1994-06-14

    Disclosed is a method of sintering ceramic materials. A compacted article comprising inorganic particles coated with carbon is provided, the carbon providing improved microwave coupling. The compacted article is then heated by microwave radiation to a temperature and for a period of time sufficient to sinter the compacted article. No Drawings

  15. DESULFURIZATION OF STEEL MILL SINTER PLANT GASES

    EPA Science Inventory

    The report gives results of an evaluation of the technical and economic feasibility of using limestone scrubbing technology to control sinter plant emissions. Data from Soviet and Japanese sinter plants employing limestone scrubbing technology were used to develop a realistic des...

  16. Method of sintering materials with microwave radiation

    DOEpatents

    Kimrey, Jr., Harold D. (Knoxville, TN); Holcombe, Jr., Cressie E. (Farragut, TN); Dykes, Norman L. (Oak Ridge, TN)

    1994-01-01

    A method of sintering ceramic materials following: A compacted article comprising inorganic particles coated with carbon is provided, the carbon providing improved microwave coupling. The compacted article is then heated by microwave radiation to a temperature and for a period of time sufficient to sinter the compacted article.

  17. Manufacture of high-density ceramic sinters

    NASA Technical Reports Server (NTRS)

    Hibata, Y.

    1986-01-01

    High density ceramic sinters are manufactured by coating premolded or presintered porous ceramics with a sealing material of high SiO2 porous glass or nitride glass and then sintering by hot isostatic pressing. The ceramics have excellent abrasion and corrosion resistances. Thus LC-10 (Si3N2 powder) and Y2O3-Al2O3 type sintering were mixed and molded to give a premolded porous ceramic (porosity 37%, relative bulk density 63%). The ceramic was dipped in a slurry containing high SiO2 porous glass and an alcohol solution of cellulose acetate and dried. The coated ceramic was treated in a nitrogen atmosphere and then sintered by hot isostatic pressing to give a dense ceramic sinter.

  18. Sintering of reaction bonded silicon nitride

    NASA Technical Reports Server (NTRS)

    Mangels, J. A.

    1983-01-01

    A process to produce sintered reaction-bonded Si3N4 (SRBSN) articles has been developed. This process consists of the addition of an appropriate sintering aid to reaction-bonded Si3N4 followed by sintering between 1780 and 2000 C, using an over pressure of nitrogen. The principal advantage of this process is the low sintering shrinkages of 5 to 10 percent. The properties and microstructure of two SRBSN systems sintered with MgO and Y2O3 additives are described and were found to be comparable to corresponding hot-pressed Si3N4 systems. Examples of applications of both systems are illustrated, demonstrating near net shape fabrication capability of the process.

  19. Simulation of Sintering of Layered Structures

    SciTech Connect

    OLEVSKY,EUGENE; TIKARE,VEENA; GARINO,TERRY J.; BRAGINSKY,MICHAEL V.

    2000-11-22

    An integrated approach, combining the continuum theory of sintering and Potts model based mesostructure evolution analysis, is used to solve the problem of bi-layered structure sintering. Two types of bi-layered structures are considered: layers of the same material with different initial porosity, and layers of two different materials. The effective sintering stress for the bi-layer powder sintering is derived, both at the meso- and the macroscopic levels. Macroscopic shape distortions and spatial distributions of porosity are determined as functions of the dimensionless specific time of sintering. The effect of the thickness of the layers on shrinkage, warpage, and pore-grain structure is studied. Ceramic ZnO powders are employed as a model experimental system to assess the model predictions.

  20. Compaction and Sintering of Mo Powders

    SciTech Connect

    Nunn, Stephen D; Kiggans, Jim; Bryan, Chris

    2013-01-01

    To support the development of Mo-99 production by NorthStar Medical Technologies, LLC, Mo metal powders were evaluated for compaction and sintering characteristics as they relate to Mo-100 accelerator target disk fabrication. Powders having a natural isotope distribution and enriched Mo-100 powder were examined. Various powder characteristics are shown to have an effect on both the compaction and sintering behavior. Natural Mo powders could be cold pressed directly to >90% density. All of the powders, including the Mo-100 samples, could be sintered after cold pressing to >90% density. As an example, a compacted Mo-100 disk reached 89.7% density (9.52 g/cm3) after sintering at 1000 C for 1 hr. in flowing Ar/4%H2. Higher sintering temperatures were required for other powder samples. The relationships between processing conditions and the resulting densities of consolidated Mo disks will be presented.

  1. Consolidation of thermites by pressing and sintering

    SciTech Connect

    Kelly, M.D.; Abney, L.D.

    1984-01-01

    Consolidated thermites can be used as chemical heat sources. Pressing and sintering, a power metallurgy technique, has been developed to consolidate thermite parts with uniform density, composition, and calorific output. These materials are safe to handle, machineable, and generate minimum gas pressure upon reaction. This technique consists of die pressing various compositions of blended thermite powders, then isostatic pressing the parts before sintering to ensure the uniform density of the thermite composites. Parts sintered at various temperatures were examined metallographically for compositional uniformity and to determine whether diffusion between the powders had occurred. Flexure and tensile strength values were obtained to determine the temperature range required to produce strong parts. The coordination of metallography and strength values for various compositions and sintering temperature resulted in data that were used to optimize the fabrication process. Consolidation of thermite by pressing and sintering was found to be a valid process for producing uniform, dense, strong thermite parts.

  2. How many ore-bearing asteroids?

    NASA Astrophysics Data System (ADS)

    Elvis, Martin

    2014-02-01

    A simple formalism is presented to assess how many asteroids contain ore, i.e., commercially profitable material, and not merely a high concentration of a resource. I apply this formalism to two resource cases: platinum group metals (PGMs) and water. Assuming for now that only Ni-Fe asteroids are of interest for PGMs, then 1% of NEOs are rich in PGMs. The dearth of ultra-low delta-v (<4.5 km s-1) NEOs larger than 100 m diameter reduces the ore-bearing fraction to only 1 in 2000 NEOs. As 100 m diameter NEOs are needed to have a value ?US$1B and the population of near-Earth objects (NEOs) larger than 100 m diameter is 20,000 (Mainzer et al., 2011) the total population of PGM ore-bearing NEOs is roughly 10. I stress that this is a conservative and highly uncertain value. For example, an order of magnitude increase in PGM ore-bearing NEOs occurs if delta-v can be as large as 5.7 km s-1. Water ore for utilization in space is likely to be found in 1/1100 NEOs. NEOs as small as 18 m diameter can be water-ore-bodies because of the high richness of water ( 20%) expected in 25% of carbonaceous asteroids, bringing the number of water-ore-bearing NEOs to 9000 out of the 10 million NEOs of this size. These small NEOs are, however, hard to find with present surveys. There will be 18 water-ore-bearing NEOs >100 m diameter. These estimates are at present highly imprecise and sensitive to small changes, especially in the maximum delta-v allowed. Nonetheless the low values found here mean that much improved determinations of each of the terms of the formalism are urgently needed. If better estimates still find small numbers of ore-bearing NEOs then thorough surveys for NEA discovery and, especially, characterization are needed. Strategies for the two classes are likely to be different.

  3. Pressureless sintered Sialons with low amounts of sintering aid

    NASA Technical Reports Server (NTRS)

    Arias, A.

    1978-01-01

    Two Beta prime - Sialons of composition Si2.6Al0.393y0.007O0.4N3.6 and Si2.6Al0.384Y0.014O0.4N3.6 were pressureless sintered from mixtures of Y2O3 and separately milled Beta -Si3N4, AlN, and SiO2. These Sialons had densities of over 98% of theoretical, four-point bend strengths of 460 and 155 MPa at room temperature and 1400 C, respectively, and 1400 C oxidation rates lower than those reported for hot pressed Si3N4 and for a stronger Sialon with 2.5 weight percentage Y2O3.

  4. Exploring the engine of anthropogenic iron cycles

    PubMed Central

    Müller, Daniel B.; Wang, Tao; Duval, Benjamin; Graedel, T. E.

    2006-01-01

    Stocks of products in use are the pivotal engines that drive anthropogenic metal cycles: They support the lives of people by providing services to them; they are sources for future secondary resources (scrap); and demand for in-use stocks generates demand for metals. Despite their great importance and their impacts on other parts of the metal cycles and the environment, the study of in-use stocks has heretofore been widely neglected. Here we investigate anthropogenic and geogenic iron stocks in the United States (U.S.) by analyzing the iron cycle over the period 1900–2004. Our results show the following. (i) Over the last century, the U.S. iron stock in use increased to 3,200 Tg (million metric tons), which is the same order of magnitude as the remaining U.S. iron stock in identified ores. On a global scale, anthropogenic iron stocks are less significant compared with natural ores, but their relative importance is increasing. (ii) With a perfect recycling system, the U.S. could substitute scrap utilization for domestic mining. (iii) The per-capita in-use iron stock reached saturation at 11–12 metric tons in ?1980. This last finding, if applicable to other economies as well, could allow a significant improvement of long-term forecasting of steel demand and scrap availability in emerging market economies and therefore has major implications for resource sustainability, recycling technology, and industrial and governmental policy. PMID:17053079

  5. Iron Aluminide Composites

    SciTech Connect

    Schneibel, J.H.

    1998-11-20

    Iron aluminides with the B2 structure are highly oxidation and corrosion resistant. They are thermodynamically compatible with a wide range of ceramics such as TiC, WC, TiB{sub 2}, and ZrB{sub 2}. In addition, liquid iron aluminides wet these ceramics very well. Therefore, FeAl/ceramic composites may be produced by techniques such as liquid phase sintering of powder mixtures, or pressureless melt infiltration of ceramic powders with liquid FeAl. These techniques, the resulting microstructure, and their advantages as well as limitations are described. Iron aluminide composites can be very strong. Room temperature flexure strengths as high as 1.8 GPa have been observed for FeAl/WC. Substantial gains in strength at elevated temperatures (1073 K) have also been demonstrated. Above 40 vol.% WC the room temperature flexure strength becomes flaw-limited. This is thought to be due to processing flaws and limited interfacial strength. The fracture toughness of FeAl/WC is unexpectedly high and follows a mile of mixtures. Interestingly, sufficiently thin (< 1 {micro}m) FeAl ligaments between adjacent WC particles fracture not by cleavage, but in a ductile manner. For these thin ligaments the dislocation pile-ups formed during deformation are not long enough to nucleate cleavage fracture, and their fracture mode is therefore ductile. For several reasons, this brittle-to-ductile size transition does not improve the fracture toughness of the composites significantly. However, since no cleavage cracks are nucleated in sufficiently thin FeAl ligaments, slow crack growth due to ambient water vapor does not occur. Therefore, as compared to monolithic iron aluminizes, environmental embrittlement is dramatically reduced in iron aluminide composites.

  6. Iron aluminide composites

    SciTech Connect

    Schneibel, J.H.

    1999-07-01

    Iron aluminides with the B2 structure are highly oxidation and corrosion resistant. They are thermodynamically compatible with a wide range of ceramics such as TiC, WC, TiB{sub 2}, and ZrB{sub 2}. In addition, liquid iron aluminides wet these ceramics very well. Therefore, FeAl/ceramic composites may be produced by techniques such as liquid phase sintering of powder mixtures, or pressureless melt infiltration of ceramic powders with liquid FeAl. These techniques, the resulting microstructures, and their advantages as well as limitations are described. Iron aluminide composites can be very strong. Room temperature flexure strengths as high as 1.8 GPa have been observed for FeAl/WC. Substantial gains in strength of elevated temperatures (1,073 K) have also been demonstrated. Above 40 vol.% WC the room temperature flexure strength becomes flaw-limited. This is thought to be due to processing flaws and limited interfacial strength. The fracture toughness of FeAl/WC is unexpectedly high and follows a rule of mixtures. Interestingly, sufficiently thin ({lt}1 {micro}m) FeAl ligaments between adjacent WC particles fracture not by cleavage, but in a ductile manner. For these thin ligaments the dislocation pile-ups formed during deformation are not long enough to nucleate cleavage fracture, and their fracture mode is therefore ductile. For several reasons, this brittle-to-ductile size transition does not improve the fracture toughness of the composites significantly. However, since no cleavage cracks are nucleated in sufficiently thin FeAl ligaments, slow crack growth due to ambient water vapor does not occur. Therefore, as compared to monolithic iron aluminides, environmental embrittlement is dramatically reduced in iron aluminide composites.

  7. Iron Mountain Electromagnetic Results

    SciTech Connect

    Gail Heath

    2012-07-01

    Iron Mountain Mine is located seventeen miles northwest of Redding, CA. After the completion of mining in early 1960s, the mine workings have been exposed to environmental elements which have resulted in degradation in water quality in the surrounding water sheds. In 1985, the EPA plugged ore stoops in many of the accessible mine drifts in an attempt to restrict water flow through the mine workings. During this process little data was gathered on the orientation of the stoops and construction of the plugs. During the last 25 years, plugs have begun to deteriorate and allow acidic waters from the upper workings to flow out of the mine. A team from Idaho National Laboratory (INL) performed geophysical surveys on a single mine drift and 3 concrete plugs. The project goal was to evaluate several geophysical methods to determine competence of the concrete plugs and orientation of the stopes.

  8. Nondestructive evaluation of sintered ceramics

    NASA Technical Reports Server (NTRS)

    Baaklini, George Y.; Klima, Stanley J.; Sanders, William A.

    1988-01-01

    Radiography and several acoustic and thermoacoustic microscopy techniques are investigated for application to structural ceramics for advanced heat engines. A comparison is made of the results obtained from the use of scanning acoustic microscopy (SAM), scanning laser acoustic microscopy (SLAM), and thermoacoustic microscopy (TAM). These techniques are evaluated on research samples of green and sintered monolithic silicon nitrides and silicon carbides in the form of modulus-of-rupture (MOR) bars containing deliberately introduced flaws. Strengths and limitations of the techniques are described, with the emphasis being on statistics of detectability of flaws that constitute potential fracture origins. Further, it is shown that radiographic evaluation and guidance helped develop uniform high-density Si3N4 MOR bars with improved four-point flexural strength (875, 544, and 462 MPa at room temperature, 1200 C, 1370 C, respectively) and reduced scatter in bend strength.

  9. INVESTIGATION OF WEAR RESISTANT MATERIAL USING DISPERSED PHASE INTERMETALLIC COMPOUND OF NICKEL-TITANIUM-SILICON IN AN IRON MATRIX

    E-print Network

    Steinmetz, C.

    2011-01-01

    diffusion layer, thus providing good metallurgical bonding,diffusion process between the G particles and the iron matrix, and thus permit longer sintering times to improve the densification and bonding.

  10. REMOVAL OF ARSENIC FROM GROUNDWATER USING NATURALLY OCCURRING IRON OXIDES IN RURAL REGIONS OF MONGOLIA

    EPA Science Inventory

    We have found that the iron oxide particles produced by grinding naturally occurring iron ores are very effective in removing arsenic from water. The arsenic adsorption isothermal of the particles h...

  11. Tribological properties of sintered polycrystalline and single crystal silicon carbide

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.; Srinivasan, M.

    1982-01-01

    Tribological studies and X-ray photoelectron spectroscopy analyses were conducted with sintered polycrystalline and single crystal silicon carbide surfaces in sliding contact with iron at various temperatures to 1500 C in a vacuum of 30 nPa. The results indicate that there is a significant temperature influence on both the friction properties and the surface chemistry of silicon carbide. The main contaminants on the as received sintered polycrystalline silicon carbide surfaces are adsorbed carbon, oxygen, graphite, and silicon dioxide. The surface revealed a low coefficient of friction. This is due to the presence of the graphite on the surface. At temperatures of 400 to 600 C graphite and copious amount of silicon dioxide were observed on the polycrystalline silicon carbide surface in addition to silicon carbide. At 800 C, the amount of the silicon dioxide decreased rapidly and the silicon carbide type silicon and carbon peaks were at a maximum intensity in the XPS spectra. The coefficients of friction were high in the temperature range 400 to 800 C. Small amounts of carbon and oxygen contaminants were observed on the as received single crystal silicon carbide surface below 250 C. Silicon carbide type silicon and carbon peaks were seen on the silicon carbide in addition to very small amount of graphite and silicon dioxide at temperatures of 450 to 800 C.

  12. Method for extraction of uranium from ores

    SciTech Connect

    Bings, H.; Fischer, P.; Kampf, F.; Pietsch, H.; Thome, R.; Turke, W.; Wargalla, G.; Winkhaus, G.

    1982-11-30

    A method for continuously extracting uranium from ores comprises the steps of: forming a slurry of ore in a leaching solution; heating the slurry while pumping it through a tube reactor at high turbulences characterized by Reynolds numbers in excess of 50,000; supplying gaseous oxygen at high pressures into the tube reactor such that the uranium is substantially completely oxidized in a soluble form but impurities in the slurry are substantially kept from becoming soluble; recovering the uranium oxide solute which is substantially free of impurities.

  13. Microwave Sinterator Freeform Additive Construction System (MS-FACS)

    NASA Technical Reports Server (NTRS)

    Howe, Alan S.; Wilcox, Brian H.; Barmatz, Martin B.; Mercury, Michael B.; Siebert, Michael A.; Rieber, Richard R.

    2013-01-01

    The harmful properties of lunar dust, such as small size, glass composition, abnormal surface area, and coatings of imbedded nanophase iron, lead to a unique coupling of the dust with microwave radiation. This coupling can be exploited for rapid sintering of lunar soil for use as a construction material that can be formed to take on an infinite number of shapes and sizes. This work describes a system concept for building structures on the lunar surface using lunar regolith (soil). This system uses the ATHLETE (All-Terrain Hex- Limbed Extra-Terrestrial Explorer) mobility system as a positioning system with a microwave print head (similar to that of a smaller-scale 3D printer). A processing system delivers the lunar regolith to the microwave print head, where the microwave print head/chamber lays down a layer of melted regolith. An arm on the ATHLETE system positions the layer depending on the desired structure.

  14. 40 CFR 440.20 - Applicability; description of the aluminum ore subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... aluminum ore subcategory. 440.20 Section 440.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Aluminum Ore Subcategory § 440.20 Applicability; description of the aluminum ore subcategory. The... an aluminum ore....

  15. 40 CFR 440.20 - Applicability; description of the aluminum ore subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... aluminum ore subcategory. 440.20 Section 440.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Aluminum Ore Subcategory § 440.20 Applicability; description of the aluminum ore subcategory. The... an aluminum ore....

  16. 40 CFR 440.20 - Applicability; description of the aluminum ore subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... aluminum ore subcategory. 440.20 Section 440.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Aluminum Ore Subcategory § 440.20 Applicability; description of the aluminum ore subcategory. The... an aluminum ore....

  17. AMT survey in the Outokumpu ore Belt, Eastern Finland

    NASA Astrophysics Data System (ADS)

    Lahti, Ilkka; Kontinen, Asko; Aatos, Soile; Smirnov, Maxim

    2015-04-01

    The Outokumpu ore belt comprises Paleoroterozoic turbiditic deep-water sediments enclosing fault-bound ophiolitic slices composed dominantly of serpentinites derived from oceanic upper mantle peridotites. These together form the allochthonous Outokumpu suite that was emplaced onto the Karelian Craton margin during the early stages of the Svecofennian Orogeny. The area which has been over 100 years among the most important mining regions in Finland is still supporting active mining and exploration. The main prospectivity is for polymetallic (Cu-Co-Zn-Ni-Ag-Au) sulfide ores that are hosted by carbonate, calc-silicate and quartz rocks fringing serpentinite bodies embedded in extensive formations of electrically conductive iron sulfide and graphite-bearing black schists that are showing no geochemical vectors to the ores (e.g. Peltonen et al., 2008). The presence of conductive schists makes also electromagnetic exploration of the sulfide ores challenging. However, the detection of the black schists at depth would be useful in locating new environments with potential for the serpentinites and prospective Outokumpu rock assemblage. Audiomagnetotelluric (AMT) data has been recently collected to image subsurface conductivity structure of the belt. These data were acquired along five profiles transecting several key-features, including the Miihkali serpentinite, Archean Sotkuma gneiss window and the area SE from the Outokumpu mine. Altogether 91 sites were measured with the site spacing of 300 m - 2 km. AMT data (f = 1 - 10 000 Hz) were acquired during daytime whereas night-recordings enabled to obtain data at the frequency range of 0.01 - 10 000 Hz. Measurements were done using two Metronix 24bit ADU-07e broadband electromagnetic acquisition systems. Robust remote reference processing yielded mostly good data quality, particularly for data recorded during night-time. The survey area is favorable for 2-D modeling as it is characterized by thin, laterally extensive conductors indicated by airborne electromagnetic data and regional strike analysis of acquired impedance tensor data. Two-dimensional inversion was done jointly for TE, TM- and Tipper data using the inversion code by Rodi and Mackie (2001). Results are visualized as sounding curves, sections of electrical conductivity and induction vectors. Results show dipping and sub-horizontal conductors southeast of the Outokumpu town. One c. 1 km deep sub-horizontal conductor is verified by a drill hole located approximately 8 km from the town. Gently eastwards dipping conductor was detected in the Miihkali serpentinite area. Conductors are absent in the uppermost ~ 7 km below the Sotkuma gneisses, which consequently represent rather a uplifted fault block than a thrust sheet of the Archaean basement rocks, thus resolving an old debate concerning the crustal structure at Sotkuma. In addition to AMT, high resolution seismic and airborne ZTEM surveys have been recently carried out in the study area providing a good opportunity to compare results from different deep penetrating geophysical methods. References Peltonen, P., Kontinen, A., Huhma, H. and Kuronen, U. 2008. Outokumpu revisited: New mineral deposit model for the mantle peridotite-associated Cu-Co-Zn-Ni-Ag-Au sulphide deposits: Ore Geology Reviews, 33, no. 3-4, 559-617. Rodi, W. and Mackie, R. 2001. Nonlinear conjugate gradients algorithm for 2-D magnetotelluric inversion. Geophysics, 66, 174-187.

  18. Evaluation of feasibility of static tests applied to Küre VMS ore deposits

    NASA Astrophysics Data System (ADS)

    Demirel, Cansu; Çelik Balci, Nurgül; ?eref Sönmez, M.

    2015-04-01

    Küre volcanogenic massive sulfide (VMS) ore deposits have been mined for its copper content for over centuries. However, there is no published data on AMD around Küre VMS ore deposits. This study investigates the sources of acid producing mechanisms in Küre, using field and laboratorial approaches. Geochemical static tests to predict AMD generation are widely applied to mining sites for assessing potential environmental consequences. However, there are well known limitations of these methods particularly resulting from assumptions used for calculations. To test the feasibility of the methods to predict potential of AMD generation of Küre (VMS) copper deposits, for the first time, acid production and neutralization potential of various mine wastes of Küre (VMS) copper deposits were determined. To test our static test results, in situ and laboratory geochemical data were also obtained from the groundwater discharges from Bakibaba underground mining tunnels. Feasibility study showed that, despite a few inconsistencies, static tests were suitable for predicting generation of AMD around Küre copper mining site and reflected well the site conditions. The current study revealed that pulp density, defined as solid/liquid ratio and used for static tests, is an important limiting factor to predict reliable data for AMD generation. In this study, we also determined surface waters affected by AMD are predicted to have a pH value between 3 and 5, with an average of pH 4. Excessive concentrations of manganese, copper, cobalt and sulfate are also noted with considerable amounts of iron and zinc, which can reach to toxic levels. Moreover, iron and zinc were found to be the controlling the fate of metals by precipitation and co-precipitation, due to their relatively depleted concentrations at redox shifting zones. Key words: Küre pyritic copper ore, Bakibaba mining tunnels, volcanogenic massive sulfide ore deposits, acid production potential, neutralization potential, feasibility, groundwater chemistry

  19. Structure of magnetite lodes at the Estyunino iron deposit in the central Urals

    NASA Astrophysics Data System (ADS)

    Rudnitsky, V. F.; Aleshin, K. B.; Kuznetsov, A. Zh.; Ivanchenko, V. S.

    2013-11-01

    The structure of magnetite lodes is determined by iron and sulfur distribution, as well as texture and structure of ore. These features have been revealed by documentation of cores from ore intervals in exploration boreholes penetrating two main lodes 21 and 22 of the Estyunino iron deposit. The documentation of cores was accompanied by sampling for microscopic examination of texture and structure of ore and selection of Fe and S contents in ore. Then these data were summarized as sections of the lodes. It was established that the structure of magnetite lodes is characterized by conformable ore layers distinguished by texture, structure, and Fe and S contents. Banded and spotty ores containing less than 50% magnetite are predominant. Layers of homogeneous massive ore are infrequent. The textural pattern indicates a volcaniclastic nature of host rocks. The spotty texture is characteristic of hyaloclastites with vitreous shards. The banded texture with oriented distribution of fiamme is inherent to volcaniclastic rocks. In both cases, magnetite selectively replaces dark-colored vitreous fragments and is also dispersed in the salic matrix and lava fragments. No indications of crosscutting superposed relationships are observed. The available data can be satisfactorily explained by an impregnation-metasomatic mode of ore deposition.

  20. SABATO 24 OTTOBRE SALA KODAK | ORE 15.00

    E-print Network

    Di Pillo, Gianni

    NOVEMBRE SALA DELUXE | ORE 11.00 Conversazioni a porte aperte nuovi scenari: America e Russia Incontro con scrittore) SALA KODAK | ORE 16.00 The African Queen (La regina d'Africa) di Howard Hawks USA, Gran Bretagna

  1. 3. DETAIL OF ORE RECEIVING PLATFORM AND GRIZZLY, VIEW TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. DETAIL OF ORE RECEIVING PLATFORM AND GRIZZLY, VIEW TO WEST. - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  2. 2. VIEW TO NORTHEAST (ORE RECEIVING PLATFORM OUT OF VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW TO NORTHEAST (ORE RECEIVING PLATFORM OUT OF VIEW TO RIGHT). - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  3. 4. DETAIL OF ORE RECEIVING PLATFORM AND GRIZZLY, VIEW TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. DETAIL OF ORE RECEIVING PLATFORM AND GRIZZLY, VIEW TO EAST. - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  4. 1. VIEW TO SOUTH (RETAINING WALL OF ORE RECEIVING PLATFORM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW TO SOUTH (RETAINING WALL OF ORE RECEIVING PLATFORM TO LEFT). - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  5. CONTEXT VIEW ACROSS ORE YARD AT MODERN SELFUNLOADING SHIP UNLOADING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONTEXT VIEW ACROSS ORE YARD AT MODERN SELF-UNLOADING SHIP UNLOADING IN FRONT OF HULETTS. LOOKING SOUTHWEST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  6. CONTEXT VIEW SHOWING MODERN TRACKS PASSING UNDER HULETTS AND ORE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONTEXT VIEW SHOWING MODERN TRACKS PASSING UNDER HULETTS AND ORE YARD. LOOKING NORTHEAST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  7. CONTEXT VIEW ACROSS ORE YARD AT MODERN SELFUNLOADING BOOM IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONTEXT VIEW ACROSS ORE YARD AT MODERN SELF-UNLOADING BOOM IN FRONT OF HULETTS. LOOKING SOUTHWEST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  8. AERIAL OVERVIEW, LOOKING NORTH, WITH FORMER TCIUS STEEL ORE MINE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    AERIAL OVERVIEW, LOOKING NORTH, WITH FORMER TCI-US STEEL ORE MINE HEADQUARTERS (BOTTOM) AND SUPERINTENDENT'S AND FOREMAN HOUSING ALONG MINNESOTA AVENUE AT CREST OF RED MOUNTAIN (TOP LEFT). - Muscoda Red Ore Mining Community, Bessemer, Jefferson County, AL

  9. 24. OVERHEAD VIEW OF MARISCAL WORKS ORE BIN FOUNDATION AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. OVERHEAD VIEW OF MARISCAL WORKS ORE BIN FOUNDATION AND CONDENSERS, TOWARD WHERE ORE DELIVERY TRACK WOULD HAVE RUN, LOOKING NORTHEAST. - Mariscal Quicksilver Mine & Reduction Works, Terlingua, Brewster County, TX

  10. OVERHEAD VIEW OF MARISCAL WORKS ORE BIN FOUNDATION AND CONDENSERS, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OVERHEAD VIEW OF MARISCAL WORKS ORE BIN FOUNDATION AND CONDENSERS, TOWARD WHERE ORE DELIVERY TRACK WOULD HAVE RUN, LOOKING NORTHEAST. - Mariscal Quicksilver Mine & Reduction Works, Terlingua, Brewster County, TX

  11. Liquid phase sintering of silicon carbide

    DOEpatents

    Cutler, R.A.; Virkar, A.V.; Hurford, A.C.

    1989-05-09

    Liquid phase sintering is used to densify silicon carbide based ceramics using a compound comprising a rare earth oxide and aluminum oxide to form liquids at temperatures in excess of 1,600 C. The resulting sintered ceramic body has a density greater than 95% of its theoretical density and hardness in excess of 23 GPa. Boron and carbon are not needed to promote densification and silicon carbide powder with an average particle size of greater than one micron can be densified via the liquid phase process. The sintered ceramic bodies made by the present invention are fine grained and have secondary phases resulting from the liquid phase. 4 figs.

  12. Liquid phase sintering of silicon carbide

    DOEpatents

    Cutler, Raymond A. (Bountiful, UT); Virkar, Anil V. (Salt Lake City, UT); Hurford, Andrew C. (Salt Lake City, UT)

    1989-01-01

    Liquid phase sintering is used to densify silicon carbide based ceramics using a compound comprising a rare earth oxide and aluminum oxide to form liquids at temperatures in excess of 1600.degree. C. The resulting sintered ceramic body has a density greater than 95% of its theoretical density and hardness in excess of 23 GPa. Boron and carbon are not needed to promote densification and silicon carbide powder with an average particle size of greater than one micron can be densified via the liquid phase process. The sintered ceramic bodies made by the present invention are fine grained and have secondary phases resulting from the liquid phase.

  13. Thermal barrier coating resistant to sintering

    DOEpatents

    Subramanian, Ramesh (Orlando, FL); Sabol, Stephen M. (Orlando, FL)

    2001-01-01

    A device (10) having a ceramic thermal barrier coating layer (16) characterized by a microstructure having gaps (18) with a sintering inhibiting material (22) disposed on the columns (20) within the gaps (18). The sintering resistant material (22) is stable over the range of operating temperatures of the device (10) and is not soluble with the underlying ceramic layer (16). For a YSZ ceramic layer (16) the sintering resistant layer (22) may preferably be aluminum oxide or yttrium aluminum oxide, deposited as a continuous layer or as nodules.

  14. TREATMENT OF HEXAVALENT CHROMIUM IN CHROMITE ORE PROCESSING SOLID WASTE USING A MIXED REDUCTANT SOLUTION OF FERROUS SULFATE AND SODIUM DITHIONITE

    EPA Science Inventory

    We developed a method for disseminating ferrous iron in the subsurface to enhance chemical reduction of hexavalent chromium (Cr(VI)) in a chromite ore processing solid waste derived from the production of ferrochrome alloy. The method utilizes ferrous sulfate (FeSO4) in combinati...

  15. Enery Efficient Press and Sinter of Titanium Powder for Low-Cost Components in Vehicle Applications

    SciTech Connect

    Thomas Zwitter; Phillip Nash; Xiaoyan Xu; Chadwick Johnson

    2011-03-31

    This is the final technical report for the Department of Energy NETL project NT01931 Energy Efficient Press and Sinter of Titanium Powder for Low-Cost Components in Vehicle Applications. Titanium has been identified as one of the key materials with the required strength that can reduce the weight of automotive components and thereby reduce fuel consumption. Working with newly developed sources of titanium powder, Webster-Hoff will develop the processing technology to manufacture low cost vehicle components using the single press/single sinter techniques developed for iron based powder metallurgy today. Working with an automotive or truck manufacturer, Webster-Hoff will demonstrate the feasibility of manufacturing a press and sinter titanium component for a vehicle application. The project objective is two-fold, to develop the technology for manufacturing press and sinter titanium components, and to demonstrate the feasibility of producing a titanium component for a vehicle application. The lowest cost method for converting metal powder into a net shape part is the Powder Metallurgy Press and Sinter Process. The method involves compaction of the metal powder in a tool (usually a die and punches, upper and lower) at a high pressure (up to 60 TSI or 827 MPa) to form a green compact with the net shape of the final component. The powder in the green compact is held together by the compression bonds between the powder particles. The sinter process then converts the green compact to a metallurgically bonded net shape part through the process of solid state diffusion. The goal of this project is to expand the understanding and application of press and sinter technology to Titanium Powder applications, developing techniques to manufacture net shape Titanium components via the press and sinter process. In addition, working with a vehicle manufacturer, demonstrate the feasibility of producing a titanium component for a vehicle. This is not a research program, but rather a project to develop a process for press and sinter of net shape Titanium components. All of these project objectives have been successfully completed.

  16. 32. INTERIOR VIEW LOOKING NORTH ON THE ORE BREAKER LEVEL. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. INTERIOR VIEW LOOKING NORTH ON THE ORE BREAKER LEVEL. THE ORE BREAKER, A BLAKE JAW CRUSHER, IS IN THE BOX IN THE LEFT OF THE PHOTOGRAPH, THE ORE TO BE BROKEN IS FED INTO THE OPENING ON THE FLOOR AND NEXT TO ORE BREAKER BOX. THE GRIZZLY BARS ARE ON THE RIGHT AND THE PULLEYS FROM THE POWER SYSTEM ARE OVERHEAD. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  17. Cognome e nome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ALGA 14 novembre 2011 Compitino (2 ore)

    E-print Network

    Robbiano, Lorenzo

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ALGA 14 novembre 2011­ Compitino (2 ore) Giustificare ogni affermazione Salvare il file CoCoA come

  18. Cognome e nome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ALGA 2 febbraio 2012 Compitino (2 ore)

    E-print Network

    Robbiano, Lorenzo

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ALGA 2 febbraio 2012­ Compitino (2 ore) Giustificare ogni affermazione Salvare il file CoCoA come

  19. A comparative study of conventionally sintered and microwave sintered nickel zinc ferrite

    SciTech Connect

    Rani, Rekha; Juneja, J. K.; Raina, K. K.; Kotnala, R. K.; Prakash, Chandra

    2014-04-24

    For the present work, nickel zinc ferrite having compositional formula Ni{sub 0.8}Zn{sub 0.2}Fe{sub 2}O{sub 4} was synthesized by conventional solid state method and sintered in conventional and microwave furnaces. Pellets were sintered with very short soaking time of 10 min at 1150 °C in microwave furnace whereas 4 hrs of soaking time was selected for conventional sintering at 1200 °C. Phase formation was confirmed by X-ray diffraction analysis technique. Scanning electron micrographs were taken for microstructural study. Dielectric properties were studied as a function of temperature. To study magnetic behavior, M-H hysteresis loops were recorded for both samples. It is observed that microwave sintered sample could obtain comparable properties to the conventionally sintered one in lesser soaking time at lower sintering temperature.

  20. Enumeration and characterization of microorganisms associated with the uranium ore deposit at Cigar Lake, Canada; Informal report

    SciTech Connect

    Francis, A.J.; Joshi-Tope, G.; Gillow, J.B.; Dodge, C.J.

    1994-03-01

    The high-grade uranium deposit at Cigar Lake, Canada, is being investigated as a natural analog for the disposal of nuclear fuel waste. Geochemical aspects of the site have been studied in detail, but the microbial ecology has not been fully investigated. Microbial populations in an ore sample and in groundwater samples from the vicinity of the ore zone were examined to determine their effect on uranium mobility. Counts of the total number of bacteria and of respiring bacteria were obtained by direct microscopy, and the viable aerobic and anaerobic bacteria were assessed as colony forming units (CFUs) by the dilution plating technique. In addition, the population distribution of denitrifiers, fermenters, iron- and sulfur-oxidizers, iron- and sulfate-reducers, and methanogens was determined by the most probable number (MPN) technique.

  1. Platinum metals magmatic sulfide ores.

    PubMed

    Naldrett, A J; Duke, J M

    1980-06-27

    Platinum-group elements (PGE) are mined predominantly from deposits that have formed by the segregation of molten iron-nickel-copper sulfides from silicate magmas. The absolute concentrations of PGE in sulfides from different deposits vary over a range of five orders of magnitude, whereas those of other chalcophile elements vary by factors of only 2 to 100. However, the relative proportions of the different PGE in a given deposit are systematically related to the nature of the parent magma. The absolute and relative concentrations of PGE in magmatic sulfides are explained in terms of the degree of partial melting of mantle peridotite required to produce the parent magma and the processes of batch equilibration and fractional segregation of sulfides. The Republic of South Africa and the U.S.S.R. together possess more than 97 percent of the world PGE reserves, but significant undeveloped resources occur in North America. The Stillwater complex in Montana is perhaps the most important example. PMID:17796685

  2. Sintering of sponge and hydride-dehydride titanium powders

    SciTech Connect

    Alman, David E.; Gerdemann, Stephen J.

    2004-04-01

    The sintering behavior of compacts produced from sponge and hydride-dehydride (HDH) Ti powders was examined. Compacts were vacuum sintered at 1200 or 1300 deg C for 30, 60, 120, 240, 480 or 960 minutes. The porosity decreased with sintering time and/or temperature in compacts produced from the HDH powders. Compacts produced from these powders could be sintered to essentially full density. However, the sintering condition did not influence the amount of porosity present in compacts produced from the sponge powders. These samples could only be sintered to a density of 97% theoretical. The sintering behavior was attributed to the chemical impurities in the powders.

  3. 18. VIEW OF CRUDE ORE BINS FROM WEST. WEST CRUDE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. VIEW OF CRUDE ORE BINS FROM WEST. WEST CRUDE ORE BIN AND TRESTLE FROM TWO JOHNS TRAMLINE TO SOUTH, CRUDE ORE BIN IN FOREGROUND. MACHINE SHOP IN BACKGROUND. THE TRAM TO PORTLAND PASSED TO NORTH OF MACHINE SHOP. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  4. 3. EAGLE MILL, DETAIL OF CRUDE ORE BIN FROM NORTH, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. EAGLE MILL, DETAIL OF CRUDE ORE BIN FROM NORTH, c. 1908-10. SHOWS EXPOSED CRUSHER HOUSE IN FRONT OF (SOUTH) CRUDE ORE BIN AND SNOW SHED ADDED OVER TRAM TRACKS. NOTE LACK OF EAST OR WEST CRUDE ORE BINS. CREDIT JW. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  5. 17. ORE DOCK, LOOKING EAST FROM HULETT NO. 1. WHEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. ORE DOCK, LOOKING EAST FROM HULETT NO. 1. WHEN BUILT IN 1911-1912, THIS WAS THE LARGEST ORE-UNLOADING DOCK ON THE GREAT LAKES. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  6. 29. ORE DOCK, LOOKING WEST; AT WORK UNLOADING THE 'GEORGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. ORE DOCK, LOOKING WEST; AT WORK UNLOADING THE 'GEORGE M. HUMPHREY'S' CARGO OF 25,000. TONS OF ORE. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  7. Adding OAI-ORE Support to Repository Platforms 

    E-print Network

    Maslov, Alexey; Mikeal, Adam; Phillips, Scott; Leggett, John; McFarland, Mark

    2009-05-17

    ?OAI?ORE?Support?to? Repository?Pla8orms? Alexey?Maslov,?Adam?Mikeal,?Sco3?Phillips,?? John?Legge3,?Mark?McFarland? Texas?Digital?Library? OR?09? Overview? ?? Texas?Digital?Library? Use?Case?for?OAI?ORE? ?? Mapping?ORE?model?to? DSpace?architecture? ?? ImplementaJon?? ?? Results...

  8. Behavior of uranium under conditions of interaction of rocks and ores with subsurface water

    NASA Astrophysics Data System (ADS)

    Omel'Yanenko, B. I.; Petrov, V. A.; Poluektov, V. V.

    2007-10-01

    The behavior of uranium during interaction of subsurface water with crystalline rocks and uranium ores is considered in connection with the problem of safe underground insulation of spent nuclear fuel (SNF). Since subsurface water interacts with crystalline rocks formed at a high temperature, the mineral composition of these rocks and uranium species therein are thermodynamically unstable. Therefore, reactions directed toward the establishment of equilibrium proceed in the water-rock system. At great depths that are characterized by hindered water exchange, where subsurface water acquires near-neutral and reducing properties, the interaction is extremely sluggish and is expressed in the formation of micro- and nanoparticles of secondary minerals. Under such conditions, the slow diffusion redistribution of uranium with enrichment in absorbed forms relative to all other uranium species is realized as well. The products of secondary alteration of Fe- and Ti-bearing minerals serve as the main sorbents of uranium. The rate of alteration of minerals and conversion of uranium species into absorbed forms is slow, and the results of these processes are insignificant, so that the rocks and uranium species therein may be regarded as unaltered. Under reducing conditions, subsurface water is always saturated with uranium. Whether water interacts with rock or uranium ore, the equilibrium uranium concentration in water is only ?10-8 mol/l. Uraninite ore under such conditions always remains stable irrespective of its age. The stability conditions of uranium ore are quite suitable for safe insulation of SNF, which consists of 95% uraninite (UO2) and is a confinement matrix for all other radionuclides. The disposal of SNF in massifs of crystalline rocks at depths below 500 m, where reducing conditions are predominant, is a reliable guarantee of high SNF stability. Under oxidizing conditions of the upper hydrodynamic zone, the rate of interaction of rocks with subsurface water increases by orders of magnitude and subsurface water is commonly undersaturated with uranium. Uranium absorbed by secondary minerals, particularly by iron hydroxides and leucoxene, is its single stable species under oxidizing conditions. The impact of oxygen-bearing water leads to destruction of uranium ore. This process is realized simultaneously at different hypsometric levels even if the permeability of the medium is variable in both the lateral and vertical directions. As a result, intervals containing uranyl minerals and relics of primary uranium ore are combined in ore-bearing zones with intervals of completely dissolved uranium minerals. A wide halo of elevated uranium contents caused by sorption is always retained at the location of uranium ore entirely destroyed by weathering. Uranium ore commonly finds itself in the aeration zone due to technogenic subsidence of the groundwater table caused by open-pit mining or pumping out of water from underground mines. The capillary and film waters that interact with rocks and ores in this zone are supplemented by free water filtering along fractures when rain falls or snow is thawing. The interaction of uranium ore with capillary water results in oxidation of uraninite, accompanied by loosening of the mineral surface, formation of microfractures, and an increase in solubility with enrichment of capillary water in uranium up to 10-4 mol/l. Secondary U(VI) minerals, first of all, uranyl hydroxides and silicates, replace uraninite, and uranium undergoes local diffusion redistribution with its sorption by secondary minerals of host rocks. The influx of free water facilitates the complete dissolution of primary and secondary uranium minerals, the removal of uranium at the sites of groundwater discharge, and its redeposition under reducing conditions at a greater depth. It is evident that the conditions of the upper hydrodynamic zone and the aeration zone are unfit for long-term insulation of SNF and high-level wastes because, after the failure of containers, the leakage of radionuclides into the environment becomes inevi

  9. In brief: Project StORe 

    E-print Network

    Pryor, Graham

    Project StORe is one of twenty-five projects supported in the UK by the JISC (http://www.jisc.ac.uk) Digital Repositories Programme, which aims to bring together people and practices from across the domains of research, learning, information...

  10. Surface phenomena during the early stages of sintering in steels modified with Fe–Mn–Si–C master alloys

    SciTech Connect

    Oro, Raquel; Campos, Mónica; Hryha, Eduard; Torralba, José Manuel

    2013-12-15

    The characteristics of the metallic powder surface play a critical role in the development of strong bonds between particles during sintering, especially when introducing elements with a high affinity for oxygen. In this study, Mn and Si have been combined in a Fe–Mn–Si–C master alloy powder in order to reduce their chemical activity and prevent oxidation during the heating stage of the sintering process. However, when this master alloy powder is mixed with an iron base powder, differences in chemical activity between both components can lead to an oxygen transfer from the iron base powder to the surface of the master alloy particles. The present research is focused on studying the evolution of the master alloy particle surface during the early stages of sintering. Surface characterization by X-ray Photoelectron Spectroscopy (XPS) shows that the master alloy powder surface is mostly covered by a thin easily reducible iron oxide layer (? 1 nm). Mn–Si particulate oxides are found as inclusions in specific areas of the surface. Evolution of oxides during sintering was studied on green compacts containing iron powder, graphite and Fe–Mn–Si–C master alloy powder that were heat treated in vacuum (10{sup ?6} mbar) at different temperatures (from 400, 600, 800 to 1000 °C) and analyzed by means of XPS. Vacuum sintering provides the necessary conditions to remove manganese and silicon oxides from the powder surface in the range of temperatures between 600 °C and 1000 °C. When sintering in vacuum, since the gaseous products from reduction processes are continuously eliminated, oxidation of master alloy particles due to oxygen transfer through the atmosphere is minimized. - Highlights: • Mn and Si were introduced in sintered steels using a master alloy powder. • Surface of the master alloy is mainly covered by an easily reducible iron oxide. • Temperature ranges for oxidation/reduction are identified. • Vacuum conditions avoid oxygen transfer to oxidation sensitive elements. • Chemical activity of Mn and Si is lowered when combined in a form of master alloy.

  11. Sintered electrode for solid oxide fuel cells

    DOEpatents

    Ruka, Roswell J. (Pittsburgh, PA); Warner, Kathryn A. (Bryan, TX)

    1999-01-01

    A solid oxide fuel cell fuel electrode is produced by a sintering process. An underlayer is applied to the electrolyte of a solid oxide fuel cell in the form of a slurry, which is then dried. An overlayer is applied to the underlayer and then dried. The dried underlayer and overlayer are then sintered to form a fuel electrode. Both the underlayer and the overlayer comprise a combination of electrode metal such as nickel, and stabilized zirconia such as yttria-stabilized zirconia, with the overlayer comprising a greater percentage of electrode metal. The use of more stabilized zirconia in the underlayer provides good adhesion to the electrolyte of the fuel cell, while the use of more electrode metal in the overlayer provides good electrical conductivity. The sintered fuel electrode is less expensive to produce compared with conventional electrodes made by electrochemical vapor deposition processes. The sintered electrodes exhibit favorable performance characteristics, including good porosity, adhesion, electrical conductivity and freedom from degradation.

  12. Thermal barrier coating resistant to sintering

    DOEpatents

    Subramanian, Ramesh; Seth, Brig B.

    2005-08-23

    A device (10) is made, having a ceramic thermal barrier coating layer (16) characterized by a microstructure having gaps (18) with a sintering inhibiting material (22) disposed on the columns (20) within the gaps (18). The sintering resistant material (22) is stable over the range of operating temperatures of the device (10), is not soluble with the underlying ceramic layer (16) and is applied by a process that is not an electron beam physical vapor deposition process. The sintering inhibiting material (22) has a morphology adapted to improve the functionality of the sintering inhibiting material (22), characterized as continuous, nodule, rivulet, grain, crack, flake and combinations thereof and being disposed within at least some of the vertical and horizontal gaps.

  13. Iron overdose

    MedlinePLUS

    Iron is an ingredient in many mineral and vitamin supplements. Iron supplements are also sold by themselves. Types include: Ferrous sulfate (Feosol, Slow Fe) Ferrous gluconate (Fergon) Ferrous fumarate (Femiron, Feostat) Note: This list may not be all-inclusive.

  14. Pressureless sintering of whisker-toughened ceramic composites

    DOEpatents

    Tiegs, T.N.

    1993-05-04

    A pressureless sintering method is disclosed for use in the production of whisker-toughened ceramic composites wherein the sintered density of composites containing up to about 20 vol. % SiC whiskers is improved by reducing the average aspect ratio of the whiskers to from about 10 to about 20. Sintering aids further improve the density, permitting the production of composites containing 20 vol. % SiC with sintered densities of 94% or better of theoretical density by a pressureless sintering method.

  15. Pressureless sintering of whiskered-toughened ceramic composites

    DOEpatents

    Tiegs, Terry N. (Lenoir City, TN)

    1994-01-01

    A pressureless sintering method is disclosed for use in the production of whisker-toughened ceramic composites wherein the sintered density of composites containing up to about 20 vol. % SiC whiskers is improved by reducing the average aspect ratio of the whiskers to from about 10 to about 20. Sintering aids further improve the density, permitting the production of composites containing 20 vol. % SiC with sintered densities of 94% or better of theoretical density by a pressureless sintering method.

  16. Pressureless sintering of whisker-toughened ceramic composites

    DOEpatents

    Tiegs, Terry N. (Lenoir City, TN)

    1993-01-01

    A pressureless sintering method is disclosed for use in the production of whisker-toughened ceramic composites wherein the sintered density of composites containing up to about 20 vol. % SiC whiskers is improved by reducing the average aspect ratio of the whiskers to from about 10 to about 20. Sintering aids further improve the density, permitting the production of composites containing 20 vol. % SiC with sintered densities of 94% or better of theoretical density by a pressureless sintering method.

  17. Mechanically sintered gallium-indium nanoparticles.

    PubMed

    Boley, John William; White, Edward L; Kramer, Rebecca K

    2015-04-01

    Liquid metal nanoparticles that are mechanically sintered at and below room temperature are introduced. This material can be sintered globally on large areas of entire deposits or locally to create liquid traces within deposits. The metallic nanoparticles are fabricated by dispersing a liquid metal in a carrier solvent via sonication. The resulting dispersion is compatible with inkjet printing, a process not applicable to the bulk liquid metal in air. PMID:25728533

  18. Thermal barrier coating resistant to sintering

    DOEpatents

    Subramanian, Ramesh; Seth, Brij B.

    2004-06-29

    A device (10) is made, having a ceramic thermal barrier coating layer (16) characterized by a microstructure having gaps (18) with a sintering inhibiting material (22) disposed on the columns (20) within the gaps (18). The sintering resistant material (22) is stable over the range of operating temperatures of the device (10), is not soluble with the underlying ceramic layer (16) and is applied by a process that is not an electron beam physical vapor deposition process.

  19. Sintering Behavior of Diboride Based Materials

    NASA Technical Reports Server (NTRS)

    Gasch, Matt; Gusman, Michael; Irby, Edward; Ellerby, Don; Beckman, Sarah; Johnson, Sylvia

    2003-01-01

    A brief history of diboride research, an overview of processing, and sintering studies are covered in this viewgraph presentation. UHTCs are a family of ceramic materials, including diborides of Hf and Zr, with extremely high melting temperatures. Spark Plasma Sintering (SPS) is a novel processing technique useful in consolidating difficult materials. The presentation also contains microphotographs of the microstructure of HfB2 and ZrB2 processed in different ways.

  20. Formation of fine particle sinterable ceramic powders

    SciTech Connect

    Micheli, A.L.

    1986-12-09

    A method is described of preparing a sinterable metal oxide ceramic precursor powder, comprising: mixing an aqueous solution of polyvalent metal cations of one or more metals taken from the group consisting of yttrium and zirconium with an aqueous solution of ammonium polyacrylate to form a metal polyacrylate precipitate, separating the precipitate from the aqueous mother liquid, burning out the organic portion of the precipitate, and calcining the ash to form a sinterable ceramic percursor powder.

  1. The Kiruna-type apatite-iron oxide system in central Sweden: geology and geochemical character

    NASA Astrophysics Data System (ADS)

    Högdahl, K.; Jonsson, E.; Nilsson, K.; Troll, V.

    2012-04-01

    The only apatite-iron oxide ores in the classic Palaeoproterozoic Bergslagen ore province, central Sweden, occur semi-continuously between Grängesberg and Idkerberget. Together, they represent the largest concentration of iron ore in this part of the Fennoscandian shield. Their mineralogy, geochemistry, geometry and host rock relations all suggest that they belong to the Kiruna-type class of deposits. The apatite-iron oxide ores in Bergslagen are hosted by 1.9 Ga variably altered, metavolcanic to meta-subvolcanic rocks ranging from rhyolitic to andesitic in composition. The region has been affected by three episodes of deformation (D1-3) and regional, greenschist to amphibolite facies metamorphism during the c. 1.9-1.8 Ga Svecokarelian orogeny. The Grängesberg deposits occur as narrow, moderately SE-dipping lenses that are concordant to S0 surfaces in the host rocks. Magnetic anomaly data indicate that they extend to a depth of at least 1.7 km. The lens geometry is mainly controlled by deformation during D2. Reverse, oblique, top-to-the NNW shear is evident in the footwall, and strain partitioning due to competence contrasts between the ore and altered host rocks resulted in flattening at competent ore lens crests, leading to asymmetrical folds with opposite vergence towards pinch areas where prolate strain prevailed. D1 is evident as a crenulated cleavage and D3 appears as gentle, large-scale open folds. Geochemical data on host rocks show a systematic enrichment in REE from the least to the most altered rocks. The ore-associated alteration assemblages and the apatite-iron oxide ore feature similar and elevated REE concentrations and profiles, suggesting a link between hydrothermal alteration and oxide ore formation. However, most ore magnetite has ?18O values between +0.3 and +3.4 ‰ (ranging from -0.4 to +4.9 ‰), consistent with fractionation of oxygen between magnetite and a felsic to intermediate magma at high temperatures (Jonsson et al. 2011). These values partly overlap with published data from the Kiruna ores, as well as with young Chilean deposits of a comparable type (Nyström et al. 2008). The lighter values can be explained by either (or a combination of both) later oxidation of the ores and a hydrothermal process of formation. A majority of moderately altered host rock ?18O (+5 to +10 ‰ (V-SMOW)), plot within the normal spectrum of igneous rocks. Based on isotope systematics, geochemistry and geological observations, we conclude that formation of these ores included a hydrothermal component, most likely directly related to an orthomagmatic process.

  2. 13. ORE DOCK, LOOKING EAST FROM HULETT NO. 1. WHEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. ORE DOCK, LOOKING EAST FROM HULETT NO. 1. WHEN BUILT IN 1911-1912, THIS WAS THE LARGEST ORE-UNLOADING DOCK ON THE GREAT LAKES. THE DOCK FEATURED FOUR HULETT UNLOADERS, EACH WITH A BUCKET CAPACITY OF 17 TONS; A 15-TON CAPACITY ORE STOCKING AND REHANDLING BRIDGE; AND A ONE-MILLION-TON CAPACITY ORE STORAGE YARD. THE WILLIAM-SEAVER-MORGAN COMPANY OF CLEVELAND BUILT THE DOCK EQUIPMENT. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  3. Sintered silicon nitrode recuperator fabrication

    NASA Technical Reports Server (NTRS)

    Gatti, A.; Chiu, W. S.; Mccreight, L. R.

    1980-01-01

    The preliminary design and a demonstration of the feasibility of fabricating submodules of an automotive Stirling engine recuperator for waste heat recovery at 370 C are described. Sinterable silicon nitride (Sialon) tubing and plates were fabricated by extrusion and hydrostatic pressing, respectively, suitable for demonstrating a potential method of constructing ceramic recuperator-type heat exchangers. These components were fired in nitrogen atmosphere to 1800 C without significant scale formation so that they can be used in the as-fired condition. A refractory glass composition (Al2O3 x 4.5 CaO.MgO x 11SiO2) was used to join and seal component parts by a brazing technique which formed strong recuperator submodules capable of withstanding repeated thermal cycling to 1370 C. The corrosion resistance of these materials to Na2SO4 + NaCl carbon mixtures was also assessed in atmospheres of air, hydrogen and CO2-N2-H2O mixtures at both 870 C and 1370 C for times to 1000 hours. No significant reaction was observed under any of these test conditions.

  4. Microstructural and continuum evolution modeling of sintering.

    SciTech Connect

    Braginsky, Michael V.; Olevsky, Eugene A.; Johnson, D. Lynn; Tikare, Veena; Garino, Terry J.; Arguello, Jose Guadalupe, Jr.

    2003-12-01

    All ceramics and powder metals, including the ceramics components that Sandia uses in critical weapons components such as PZT voltage bars and current stacks, multi-layer ceramic MET's, ahmindmolybdenum & alumina cermets, and ZnO varistors, are manufactured by sintering. Sintering is a critical, possibly the most important, processing step during manufacturing of ceramics. The microstructural evolution, the macroscopic shrinkage, and shape distortions during sintering will control the engineering performance of the resulting ceramic component. Yet, modeling and prediction of sintering behavior is in its infancy, lagging far behind the other manufacturing models, such as powder synthesis and powder compaction models, and behind models that predict engineering properties and reliability. In this project, we developed a model that was capable of simulating microstructural evolution during sintering, providing constitutive equations for macroscale simulation of shrinkage and distortion during sintering. And we developed macroscale sintering simulation capability in JAS3D. The mesoscale model can simulate microstructural evolution in a complex powder compact of hundreds or even thousands of particles of arbitrary shape and size by 1. curvature-driven grain growth, 2. pore migration and coalescence by surface diffusion, 3. vacancy formation, grain boundary diffusion and annihilation. This model was validated by comparing predictions of the simulation to analytical predictions for simple geometries. The model was then used to simulate sintering in complex powder compacts. Sintering stress and materials viscous module were obtained from the simulations. These constitutive equations were then used by macroscopic simulations for simulating shrinkage and shape changes in FEM simulations. The continuum theory of sintering embodied in the constitutive description of Skorohod and Olevsky was combined with results from microstructure evolution simulations to model shrinkage and deformation during. The continuum portion is based on a finite element formulation that allows 3D components to be modeled using SNL's nonlinear large-deformation finite element code, JAS3D. This tool provides a capability to model sintering of complex three-dimensional components. The model was verified by comparing to simulations results published in the literature. The model was validated using experimental results from various laboratory experiments performed by Garino. In addition, the mesoscale simulations were used to study anisotropic shrinkage in aligned, elongated powder compacts. Anisotropic shrinkage occurred in all compacts with aligned, elongated particles. However, the direction of higher shrinkage was in some cases along the direction of elongation and in other cases in the perpendicular direction depending on the details of the powder compact. In compacts of simple-packed, mono-sized, elongated particles, shrinkage was higher in the direction of elongation. In compacts of close-packed, mono-sized, elongated particles and of elongated particles with a size and shape distribution, the shrinkage was lower in the direction of elongation. We also explored the concept of a sintering stress tensor rather than the traditional sintering stress scalar concept for the case of anisotropic shrinkage. A thermodynamic treatment of this is presented. A method to calculate the sintering stress tensor is also presented. A user-friendly code that can simulate microstructural evolution during sintering in 2D and in 3D was developed. This code can run on most UNIX platforms and has a motif-based GUI. The microstructural evolution is shown as the code is running and many of the microstructural features, such as grain size, pore size, the average grain boundary length (in 2D) and area (in 3D), etc. are measured and recorded as a function of time. The overall density as the function of time is also recorded.

  5. DETAIL VIEW OF LOWER TRAM TERMINAL, SECONDARY ORE BIN, CRUSHER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF LOWER TRAM TERMINAL, SECONDARY ORE BIN, CRUSHER FOUNDATION, AND BALL MILL FOUNDATIONS, LOOKING NORTH NORTHWEST. ORE FROM THE MINES WAS DUMPED FROM THE TRAM BUCKETS INTO THE PRIMARY ORE BIN UNDER THE TRAM TERMINAL. A SLIDING CONTROL DOOR INTRODUCED THE INTO THE JAW CRUSHER (FOUNDATIONS,CENTER). THE CRUSHED ORE WAS THEN CONVEYED INTO THE SECONDARY ORE BIN AT CENTER LEFT. A HOLE IN THE FLOOR OF THE ORE BIN PASSED ORE ONTO ANOTHER CONVEYOR THAT BROUGHT IT OUT TO THE BALL MILL(FOUNDATIONS,CENTER BOTTOM). THIS SYSTEM IS MOST LIKELY NOT THE ORIGINAL SET UP, PROBABLY INSTALLED IN THE MINE'S LAST OCCUPATION IN THE EARLY 1940s. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  6. Mining and beneficiation of lunar ores

    NASA Technical Reports Server (NTRS)

    Bunch, T. E.; Williams, R. J.; Mckay, D. S.; Giles, D.

    1979-01-01

    The beneficiation of lunar plagioclase and ilmenite ores to feedstock grade permits a rapid growth of the space manufacturing economy by maximizing the production rate of metals and oxygen. A beneficiation scheme based on electrostatic and magnetic separation is preferred over conventional schemes, but such a scheme cannot be completely modeled because beneficiation processes are empirical and because some properties of lunar minerals have not been measured. To meet anticipated shipping and processing needs, the peak lunar mining rate will exceed 1000 tons/hr by the fifth year of operation. Such capabilities will be best obtained by automated mining vehicles and conveyor systems rather than trucks. It may be possible to extract about 40 kg of volatiles (60 percent H2O) by thermally processing the less than 20 micron ilmenite concentrate extracted from 130 tons of ilmenite ore. A thermodynamic analysis of an extraction process is presented.

  7. Pressure leaching las cruces copper ore

    NASA Astrophysics Data System (ADS)

    Berezowsky, R. M.; Xue, T.; Collins, M. J.; Makwana, M.; Barton-Jones, I.; Southgate, M.; Maclean, J. K.

    1999-12-01

    A hydrometallurgical process was developed for treating the Las Cruces massive sulfide-ore deposit located near Seville, Spain. A two-stage countercurrent leach process, consisting of an atmospheric leach and a pressure leach, was developed to effectively leach copper from the copper-bearing minerals and to generate a solution suitable for the subsequent solvent-extraction and copper-electrowinning operations. The results of batch and continuous miniplant tests are presented.

  8. Gravitational Effects on Distortion in Sintering

    NASA Technical Reports Server (NTRS)

    German, Randall M.

    2003-01-01

    During sintering a powder compact gains strength through low-temperature interparticle bonding, usually induced by solid-state surface diffusion, followed by further strength contributions from high-temperature densification. In cases where a liquid phase forms, sintering densification is accelerated and shape retention is sustained while open pores remain and contribute capillary forces. Unfortunately, sintering densification requires the compact become thermally softened to a point where creep strain rates reach levels near 10(exp -2)/s when the liquid forms. On the other hand, thermal softening of the powder compact substantially reduces the strength at high temperatures. Therefore, the in situ strength evolution during sintering is a primary focus to separate compact densification (as required for high performance) with minimized distortion (as required for net-shaping). With respect to gravitation effects on distortion during sintering there are two points of substantial weakness - prior to significant interparticle bonding and during final pore closure. This research is focused on understanding the competition among interparticle neck growth, densification, thermal softening, grain boundary wetting, capillary effects associated with liquid wetting and residual porosity, and gravity. Most surprising is the apparent role of gravity, where the deviatoric stress acting on the powder structure induces skeletal formation that reduces distortion. In contrast with theory, microgravity samples exhibit more distortion yet fail to fully densify. Results are presented on the experimental concepts supporting an emerging model of sintering strength evolution that enables understanding of both distortion and densification. The experiments have relied on tungsten heavy alloys, various combinations of dihedral angle, pore size, initial porosity, liquid:solid ratio, and heating rates. On Earth, the dominant factor with respect to distortion is the starting body heterogeneity. Current modeling efforts are seeking some means to uniformly predict the distortion based on a starting pore structure heterogeneity parameter. Densification is largely unaffected by the initial pore structure, but distortion is highly variable, suggesting that nonuniform pore closure might be a significant parameter during sintering. With respect to flight experiments, plans include removal of the solid body forces acting on the solid grains, allowing stabilization of the pore structure and examination of the buoyancy effects with regard to distortion. In microgravity there is the surprising result that compacts do not densify, yet distort a factor that is contrary to all current sintering models. Densification without distortion during liquid phase sintering was achieved by manipulating microstructure and its evolution during sintering. Microstructure parameters such as the solid volume fraction, dihedral angle, initial porosity, and pore size were varied to measure densification and distortion behavior during LPS using W-Ni-Cu alloys. Green compacts were formed using ethylene-bis-stearamide as a pore-forming agent with the amount of polymer controlling the initial porosity. Different initial pore sizes were generated by varying the polymer particle size. Dihedral angle was varied by changing the Ni:Cu ratio in the alloys. Finally, the solid volume fraction was adjusted via the tungsten content. Distortion was quantified using profiles determined with a coordinate measuring machine to calculate a distortion parameter. Sintering results showed that solid volume fraction and dihedral angle are the dominant factors on densification and distortion during liquid phase sintering. Distortion decreases with increasing solid volume fraction and dihedral angle, while initial porosity and pore size have no observable effect on distortion at nearly full densification. Various strategies emerge to improve distortion control in liquid phase sintering.

  9. Nonisothermal viscous sintering of volcanic ash

    NASA Astrophysics Data System (ADS)

    Wadsworth, Fabian B.; Vasseur, Jérémie; Aulock, Felix W.; Hess, Kai-Uwe; Scheu, Bettina; Lavallée, Yan; Dingwell, Donald B.

    2014-12-01

    Volcanic ash is often deposited in a hot state. Volcanic ash containing glass, deposited above the glass transition interval, has the potential to sinter viscously both to itself (particle-particle) and to exposed surfaces. Here we constrain the kinetics of this process experimentally under nonisothermal conditions using standard glasses. In the absence of external load, this process is dominantly driven by surface relaxation. In such cases the sintering process is rate limited by the melt viscosity, the size of the particles and the melt-vapor interfacial tension. We propose a polydisperse continuum model that describes the transition from a packing of particles to a dense pore-free melt and evaluate its efficacy in describing the kinetics of volcanic viscous sintering. We apply our model to viscous sintering scenarios for cooling crystal-poor rhyolitic ash using the 2008 eruption of Chaitén volcano as a case example. We predict that moderate linear cooling rates of > 0.1°C min-1 can result in the common observation of incomplete sintering and the preservation of pore networks.

  10. Speciation and characterization of arsenic in gold ores and cyanidation tailings using X-ray absorption spectroscopy

    USGS Publications Warehouse

    Paktunc, D.; Foster, A.; Heald, S.; Laflamme, G.

    2004-01-01

    The knowledge of mineralogy and molecular structure of As is needed to better understand the stability of As in wastes resulting from processing of gold ores. In this study, optical microscopy, scanning electron microscopy, electron microprobe, X-ray diffraction and X-ray absorption fine structure (XAFS) spectroscopy (including both XANES and EXAFS regimes) were employed to determine the mineralogical composition and local coordination environment of As in gold ores and process tailings from bench-scale tests designed to mimic a common plant practice. Arsenic-bearing minerals identified in the ores and tailings include iron (III) oxyhydroxides, scorodite (FeAsO4??2H2O), ferric arsenates, arseniosiderite (Ca2Fe3 (AsO4)3O2??3H2O), Ca-Fe arsenates, pharmacosiderite (KFe4 (AsO4)3(OH)4??6-7H2O), jarosite (K2Fe6(SO4)4 (OH)12) and arsenopyrite (FeAsS). Iron (III) oxyhydroxides contain variable levels of As from trace to about 22 wt% and Ca up to approximately 9 wt%. Finely ground ore and tailings samples were examined by bulk XAFS and selected mineral grains were analyzed by microfocused XAFS (micro-EXAFS) spectroscopy to reconcile the ambiguities of multiple As sources in the complex bulk EXAFS spectra. XANES spectra indicated that As occurs as As5+in all the samples. Micro-EXAFS spectra of individual iron (III) oxyhydroxide grains with varying As concentrations point to inner-sphere bidentate-binuclear arsenate complexes as the predominant form of As. There are indications for the presence of a second Fe shell corresponding to bidentate-mononuclear arrangement. Iron (III) oxyhydroxides with high As concentrations corresponding to maximum adsorption densities probably occur as nanoparticles. The discovery of Ca atoms around As in iron (III) oxyhydroxides at interatomic distances of 4.14-4.17 A?? and the coordination numbers suggest the formation of arseniosiderite-like nanoclusters by coprecipitation rather than simple adsorption of Ca onto iron (III) oxyhydroxides. Correlation of Ca with As in iron (III) oxyhydroxides as determined by electron microprobe analysis supports the coprecipitate origin for the presence of Ca in iron (III) oxyhydroxides. The samples containing higher abundances of ferric arsenates released higher As concentrations during the cyanidation tests. The presence of highly soluble ferric arsenates and Ca-Fe arsenates, and relatively unstable iron (III) oxyhydroxides with Fe/As molar ratios of less than 4 in the ore and process tailings suggests that not only the tailings in the impoundment will continue to release As, but also there is the potential for mobilization of As from the natural sources such as the unmined ore. ?? 2004 Elsevier Ltd.

  11. Physical-chemical conditions of ore deposition

    USGS Publications Warehouse

    Barton, P.B., Jr.

    1981-01-01

    Ore deposits form under a wide range of physical and chemical conditions, but those precipitating from hot, aqueous fluids-i.e. the hydrothermal deposits-form generally below 700??C and at pressures of only 1 or 2 kbar or less. Natural aqueous fluids in rocks may extract metal and sulfur from a variety of rock types or may acquire them as a residual heritage from a crystallizing silicate magma. Ore-forming hydrothermal fluids never appear as hot springs (except in deep, submarine situations) because they boil, mix with surface waters, and cool, thereby losing their ore-bearing ability before reaching the surface. Mineral systems function as chemical buffers and indicators just as buffers and indicators function in a chemical laboratory. By reading the record written in the buffer/indicator assemblages of minerals one can reconstruct many aspects of the former chemical environment. By studying the record of changing conditions one may deduce information regarding the processes functioning to create the succession of chemical environments and the ore deposits they represent. The example of the OH vein at Creede, Colorado, shows a pH buffered by the K-feldspar + muscovite + quartz assemblage and the covariation of S2 and O2 buffered by the assemblage chlorite + pyrite + quartz. Boiling of the ore fluid led to its oxidation to hematite-bearing assemblages and simultaneously produced an intensely altered, sericitic capping over the vein in response to the condensation of vapors bearing acidic components. The solubility of metals as calculated from experimental and theoretical studies of mineral solubility appears too low by at least one or two powers of ten to explain the mineralization at Creede. In contrast to Creede where the mineral stabilities all point to a relatively consistent chemistry, the Mississippi Valley type deposits present a puzzle of conflicting chemical clues that are impossible to reconcile with any single equilibrium situation. Thus we must seriously consider metastable equilibria; those most likely involve redox disequilibrium among the sulfur species in solution and perhaps also involve organic compounds. ?? 1981.

  12. Thermal evolution and sintering of chondritic planetesimals

    E-print Network

    Henke, Stephan; Trieloff, Mario; Schwarz, Winfried H; Kleine, Thorsten

    2011-01-01

    The major aim of this study is to assess the effects of sintering of initially porous material on the thermal evolution of planetesimals, and to constrain the values of basic parameters that determined the structure and evolution of the H chondrite parent body. A new code is presented for modeling the thermal evolution of ordinary chondrite parent bodies that initially are highly porous and undergo sintering by hot pressing as they are heated by decay of radioactive nuclei. The pressure and temperature stratification in the interior of the bodies is calculated by solving the equations of hydrostatic equilibrium and energy transport. The decrease of porosity of the granular material by hot pressing due to self-gravity is followed by solving a set of equations for the sintering of powder materials. For the heat conductivity of granular material we combine recently measured data for highly porous powder materials, relevant for the surface layers of planetesimals, with data for heat conductivity of chondrite mate...

  13. Activation pretreatment of limonitic laterite ores by alkali-roasting using NaOH

    NASA Astrophysics Data System (ADS)

    Guo, Qiang; Qu, Jing-Kui; Qi, Tao; Wei, Guang-Ye; Han, Bing-Bing

    2012-02-01

    Activation pretreatment of Cr-containing limonitic laterite ores by NaOH roasting to remove Cr, Al, and Si, as well as its effect on Ni and Co extraction in the subsequent pressure acid leaching process was investigated. Characterization results of X-ray diffraction (XRD) and scanning electron microscopy/X-ray energy dispersive spectroscopy (SEM/XEDS) show that goethite is the major Ni-bearing mineral, and chromite is the minor one. Experimental results show that the leaching rates of Cr, Al, and Si are 95.6wt%, 83.8wt%, and 40.1wt%, respectively, under the optimal alkali-roasting conditions. Compared with the direct pressure acid leaching of laterite ores, the leaching rates of Ni and Co increase from 80.1wt% to 96.9wt% and 70.2wt% to 95.1wt% after pretreatment, respectively. Meanwhile, the grade of acid leaching iron residues increases from 54.4wt% to 62.5wt%, and these residues with low Cr content are more suitable raw materials for iron making.

  14. A circulation mud system used in long-distance ore pipeline transportation

    NASA Astrophysics Data System (ADS)

    Li, Youling; Wang, Hua

    2011-10-01

    The long-distance ore pipeline transportation is a new and high-tech industry, which is non-polluting, zero emissions, and in line with the strategy needs of national low-carbon economy and energy demand reduction. The long-distance ore transport needs multi-station pumping station transportation, however, the low concentration slurry that does not match the technological requirements, such as slurry head and so on. This paper designs a circulation mud system used in long-distance pipeline transportation, which solves the following issues: (1) the technical pool can't storage water during the period of cleaning mine, so can't meet the needs of non-suspension production; (2) slurry spot cool dry easy to bring serious environmental pollution; (3) the refined iron dug out from the process pool need transport to iron and steel industry, trucking transportation needs a huge costs. Experience has shown that the system effectively improve the production efficiency and propagate.

  15. Raman spectroscopy of efflorescent sulfate salts from Iron Mountain Mine Superfund Site, California

    USGS Publications Warehouse

    Sobron, Pablo; Alpers, Charles N.

    2013-01-01

    The Iron Mountain Mine Superfund Site near Redding, California, is a massive sulfide ore deposit that was mined for iron, silver, gold, copper, zinc, and pyrite intermittently for nearly 100 years. As a result, both water and air reached the sulfide deposits deep within the mountain, producing acid mine drainage consisting of sulfuric acid and heavy metals from the ore. Particularly, the drainage water from the Richmond Mine at Iron Mountain is among the most acidic waters naturally found on Earth. The mineralogy at Iron Mountain can serve as a proxy for understanding sulfate formation on Mars. Selected sulfate efflorescent salts from Iron Mountain, formed from extremely acidic waters via drainage from sulfide mining, have been characterized by means of Raman spectroscopy. Gypsum, ferricopiapite, copiapite, melanterite, coquimbite, and voltaite are found within the samples. This work has implications for Mars mineralogical and geochemical investigations as well as for terrestrial environmental investigations related to acid mine drainage contamination.

  16. Kinetics of the solid-state carbothermic reduction of wessel manganese ores

    NASA Astrophysics Data System (ADS)

    Akdogan, Guven; Eric, R. Hurman

    1995-02-01

    Reduction of manganese ores from the Wessel mine of South Africa has been investigated in the temperature range 1100 °C to 1350 °C with pure graphite as the reductant under argon atmosphere. The rate and degree of reduction were found to increase with increasing temperature and decreasing particle sizes of both the ore and the graphite. The reduction was found to occur in two stages: (1) The first stage includes the rapid reduction of higher oxides of manganese and iron to MnO and FeO. The rate control appears to be mixed, both inward diffusion of CO and outward diffusion of CO2 across the porous product layer, and the reaction of carbon monoxide on the pore walls of the oxide phase play important roles. The values of effective CO-CO2 diffusivities generated by the mathematical model are in the range from 2.15 x 10-5 to 6.17 X 10-5 cm2.s-1 for different ores at 1300 °C. Apparent activation energies range from 81. 3 to 94.6 kJ/kg/mol. (2) The second stage is slower during which MnO and FeO are reduced to mixed carbide of iron and manganese. The chemical reaction between the manganous oxide and carbon dissolved in the metal phase or metal carbide seems to be the rate-controlling process The rate constant of chemical reaction between MnO and carbide on the surface of the impervious core was found to lie in the range from 1.53 x 10-8 to 1.32 x 10-7 mol . s-1 . cm-2. Apparent activation energies calculated are in the range from 102.1 to 141.7 kJ/kg/mol.

  17. ASTER, ALI and Hyperion sensors data for lithological mapping and ore minerals exploration.

    PubMed

    Beiranvand Pour, Amin; Hashim, Mazlan

    2014-01-01

    This paper provides a review of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Advanced Land Imager (ALI), and Hyperion data and applications of the data as a tool for ore minerals exploration, lithological and structural mapping. Spectral information extraction from ASTER, ALI, and Hyperion data has great ability to assist geologists in all disciplines to map the distribution and detect the rock units exposed at the earth's surface. The near coincidence of Earth Observing System (EOS)/Terra and Earth Observing One (EO-1) platforms allows acquiring ASTER, ALI, and Hyperion imagery of the same ground areas, resulting accurate information for geological mapping applications especially in the reconnaissance stages of hydrothermal copper and gold exploration, chromite, magnetite, massive sulfide and uranium ore deposits, mineral components of soils and structural interpretation at both regional and district scales. Shortwave length infrared and thermal infrared bands of ASTER have sufficient spectral resolution to map fundamental absorptions of hydroxyl mineral groups and silica and carbonate minerals for regional mapping purposes. Ferric-iron bearing minerals can be discriminated using six unique wavelength bands of ALI spanning the visible and near infrared. Hyperion visible and near infrared bands (0.4 to 1.0 ?m) and shortwave infrared bands (0.9 to 2.5 ?m) allowed to produce image maps of iron oxide minerals, hydroxyl-bearing minerals, sulfates and carbonates in association with hydrothermal alteration assemblages, respectively. The techniques and achievements reviewed in the present paper can further introduce the efficacy of ASTER, ALI, and Hyperion data for future mineral and lithological mapping and exploration of the porphyry copper, epithermal gold, chromite, magnetite, massive sulfide and uranium ore deposits especially in arid and semi-arid territory. PMID:25674434

  18. Process for microwave sintering boron carbide

    DOEpatents

    Holcombe, Cressie E. (440 Sugarwood Dr., Knoxville, TN 37922); Morrow, Marvin S. (Rte. #3, Box 113, Kingston, TN 37763)

    1993-01-01

    A method of microwave sintering boron carbide comprises leaching boron carbide powder with an aqueous solution of nitric acid to form a leached boron carbide powder. The leached boron carbide powder is coated with a glassy carbon precursor to form a coated boron carbide powder. The coated boron carbide powder is consolidated in an enclosure of boron nitride particles coated with a layer of glassy carbon within a container for microwave heating to form an enclosed coated boron carbide powder. The enclosed coated boron carbide powder is sintered within the container for microwave heating with microwave energy.

  19. Process for microwave sintering boron carbide

    DOEpatents

    Holcombe, C.E.; Morrow, M.S.

    1993-10-12

    A method of microwave sintering boron carbide comprises leaching boron carbide powder with an aqueous solution of nitric acid to form a leached boron carbide powder. The leached boron carbide powder is coated with a glassy carbon precursor to form a coated boron carbide powder. The coated boron carbide powder is consolidated in an enclosure of boron nitride particles coated with a layer of glassy carbon within a container for microwave heating to form an enclosed coated boron carbide powder. The enclosed coated boron carbide powder is sintered within the container for microwave heating with microwave energy.

  20. Fusibility and sintering characteristics of ash

    SciTech Connect

    Ots, A. A.

    2012-03-15

    The temperature characteristics of ash fusibility are studied for a wide range of bituminous and brown coals, lignites, and shales with ratios R{sub B/A} of their alkaline and acid components between 0.03 and 4. Acritical value of R{sub B/A} is found at which the fusion temperatures are minimal. The sintering properties of the ashes are determined by measuring the force required to fracture a cylindrical sample. It is found that the strength of the samples increases sharply at certain temperatures. The alkali metal content of the ashes has a strong effect on their sintering characteristics.

  1. Sintering atmosphere effects on tensile properties of heavy alloys

    NASA Astrophysics Data System (ADS)

    Bose, A.; German, R. M.

    1988-10-01

    The sintering atmosphere has a direct bearing on the residual porosity which in turn has a strong negative influence on the tensile properties of W-Ni-Fe heavy alloys. The present investigation uses various sintering atmospheres to understand pore formation, densification, microstructure, and tensile properties of heavy alloys with tungsten contents ranging from 88 to 97 wt Pct. Pore formation when sintering in a dry hydrogen atmosphere is linked to water vapor generation and its entrapment in pores. A hydrogen dew point effect is associated with solution-reprecipitation of tungsten during liquid phase sintering. The beneficial effect of vacuum sintering has been analyzed in terms of removal of the gases before pore closure. Property degradation during long time vacuum sintering is attributed to preferential matrix vaporization. The negative effect of long sintering times in dry hydrogen is attributed to pore coarsening, which is removed by a three-stage sintering atmosphere treatment.

  2. Characterizing megascopic textures in fluorospar ores at Okorusu mine

    NASA Astrophysics Data System (ADS)

    Hagni, Richard D.; Shivdasan, Purnima A.

    2000-04-01

    Recent field mapping in two open pits at the Okorusu fluorspar mine in Namibia confirmed the presence of a variety of host rocks that were replaced by fluorite ores. The presence of certain textures in the fluorite ores can be used to identify the original host rock that was replaced. The character of the original host rock prior to fluorite replacement, in turn, has a significant controlling influence upon the beneficiation problems that are experienced for those ores.

  3. 37. VIEW NORTH FROM EAST CRUDE ORE BIN TO CRUSHER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. VIEW NORTH FROM EAST CRUDE ORE BIN TO CRUSHER ADDITION AND CRUSHED OXIDIZED ORE BIN. VISIBLE ARE DINGS MAGNETIC PULLEY (CENTER), THE 100-TON STEEL CRUSHED UNOXIDIZED ORE BIN, AND UPPER PORTION OF THE STEPHENS-ADAMSON 25 TON/HR BUCKET ELEVATOR. THE UPPER TAILINGS POND LIES BEYOND THE MILL WITH THE UPPER TAILINGS DAM UNDER THE GRAVEL ROAD IN THE UPPER RIGHT CORNER. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  4. Sintered-reaction Bonded Silicon Nitride Densified by a Gas Pressure Sintering Process Effects of Rare Earth Oxide Sintering Additives

    SciTech Connect

    Lee, S. H.; Ko, J. W.; Park, Y. J.; Kim, H. D.; Lin, Hua-Tay; Becher, Paul F

    2012-01-01

    Reaction-bonded silicon nitrides containing rare-earth oxide sintering additives were densified by gas pressure sintering. The sintering behavior, microstructure and mechanical properties of the resultant specimens were analyzed. For that purpose, Lu2O3-SiO2 (US), La2O3-MgO (AM) and Y2O3-Al2O3 (YA) additive systems were selected. Among the tested compositions, densification of silicon nitride occurred at the lowest temperature when using the La2O3-MgO system. Since the Lu2O3-SiO2 system has the highest melting temperature, full densification could not be achieved after sintering at 1950oC. However, the system had a reasonably high bending strength of 527 MPa at 1200oC in air and a high fracture toughness of 9.2 MPa m1/2. The Y2O3-Al2O3 system had the highest room temperature bending strength of 1.2 GPa

  5. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... mercury ore subcategory. 440.40 Section 440.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The provisions... produce mercury ores; and (b) mills beneficiating mercury ores by gravity separation methods or by...

  6. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... mercury ore subcategory. 440.40 Section 440.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The provisions... produce mercury ores; and (b) mills beneficiating mercury ores by gravity separation methods or by...

  7. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... mercury ore subcategory. 440.40 Section 440.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The provisions... produce mercury ores; and (b) mills beneficiating mercury ores by gravity separation methods or by...

  8. 4. TROJAN MILL, DETAIL OF CRUDE ORE BINS FROM NORTH, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. TROJAN MILL, DETAIL OF CRUDE ORE BINS FROM NORTH, c. 1912. SHOWS TIMBER FRAMING UNDER CONSTRUCTION FOR EAST AND WEST CRUDE ORE BINS AT PREVIOUS LOCATION OF CRUSHER HOUSE, AND SNOW SHED PRESENT OVER SOUTH CRUDE ORE BIN WITH PHASE CHANGE IN SNOW SHED CONSTRUCTION INDICATED AT EAST END OF EAST CRUDE ORE BIN. THIS PHOTOGRAPH IS THE FIRST IMAGE OF THE MACHINE SHOP, UPPER LEFT CORNER. CREDIT JW. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  9. The x-ray tomography of a siliceous silver ore

    NASA Astrophysics Data System (ADS)

    Chen, T. T.; Sasov, A.; Dutrizac, J. E.; Kondos, P.; Poirier, G.

    2006-03-01

    The scanning-electron microscopy and high-resolution x-ray computed tomography of siliceous silver ore fragments revealed that the ore consists almost entirely of porous masses of quartz. The quartz contains numerous pores with sizes ranging from <1 ?m to several millimeters. Silver occurs as <1 ?m sized particles in the micropores or embedded in the quartz matrix adjacent to the micropores. However, the pores have limited connections to one another. The fine pore sizes, together with the limited pore connections, greatly reduce the permeability of the ore. The implication is that very fine grinding of the ore is required to improve silver extractions by hydrometallurgical methods.

  10. Experimenting With Ore: Creating the Taconite Process; flow chart of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Experimenting With Ore: Creating the Taconite Process; flow chart of process - Mines Experiment Station, University of Minnesota, Twin Cities Campus, 56 East River Road, Minneapolis, Hennepin County, MN

  11. Recovery of Cu and Zn from Complex Sulphide Ore

    NASA Astrophysics Data System (ADS)

    Talapaneni, Trinath; Sarkar, S.; Yedla, N.; Reddy, P. L. N., Dr

    2015-02-01

    Complex Sulphide Ores are often found to be a close mutual association with each other and with the nonmetallic gangue. The beneficiation experiments showed that it would be very difficult to recover Cu and Zn from the lean complex Sulphide ores using traditional ore beneficiation methods. In the present work, leaching of complex sulfide ores in sulfuric acid was investigated by the Electro hydrometallurgy process. The lab-scale experiments were conducted to investigate the influences of pulp-density, electrolyte concentration, particle size, current density and time on recovery of Cu and Zn. The leach liquor obtained after electrolysis was subjected to Atomic Absorption Spectroscopy analysis for the recovery of minerals.

  12. Microwave sintering of single plate-shaped articles

    DOEpatents

    Katz, J.D.; Blake, R.D.

    1995-07-11

    Apparatus and method are disclosed for high temperature sintering of plate-shaped articles of alumina, magnesia, silica, yttria, zirconia, and mixtures thereof using microwave radiation. An article is placed within a sintering structure located within a sintering container which is placed in a microwave cavity for heating. The rates at which heating and cooling take place is controlled. 2 figs.

  13. Microwave sintering of single plate-shaped articles

    DOEpatents

    Katz, Joel D. (Los Alamos, NM); Blake, Rodger D. (Tucson, AZ)

    1995-01-01

    Apparatus and method for high temperature sintering of plate-shaped articles of alumina, magnesia, silica, yttria, zirconia, and mixtures thereof using microwave radiation. An article is placed within a sintering structure located within a sintering container which is placed in a microwave cavity for heating. The rates at which heating and cooling take place is controlled.

  14. Effect of mineralizers on the sintering of porcelain bodies (a review)

    SciTech Connect

    Maslennikova, G.N.; Koneshova, T.I.

    1987-11-01

    The authors assess the effects of a wide range of mineralizing agents on the structure formation of porcelain in order to arrive at optimal crystallization and structure parameters for the resulting porcelain crystals and to determine those agents which best contribute to the energy efficiency of the sintering process. The assessment is carried out specifically for the kinetics of mullite formation. Reagents tested include salts of sodium, potassium, lithium, calcium, magnesium, zinc, and aluminum, and the oxides of chromium, titanium, iron, zirconium, molybdenum, boron, and tin.

  15. Iron deficiency anemia

    MedlinePLUS

    Treatment may include taking iron supplements and eating iron-rich foods . Iron supplements (most often ferrous sulfate) are needed ... the body's iron stores in the bone marrow. Iron-rich foods include: Chicken and turkey Dried lentils, peas, and ...

  16. Sintered electrode for solid oxide fuel cells

    DOEpatents

    Ruka, R.J.; Warner, K.A.

    1999-06-01

    A solid oxide fuel cell fuel electrode is produced by a sintering process. An underlayer is applied to the electrolyte of a solid oxide fuel cell in the form of a slurry, which is then dried. An overlayer is applied to the underlayer and then dried. The dried underlayer and overlayer are then sintered to form a fuel electrode. Both the underlayer and the overlayer comprise a combination of electrode metal such as nickel, and stabilized zirconia such as yttria-stabilized zirconia, with the overlayer comprising a greater percentage of electrode metal. The use of more stabilized zirconia in the underlayer provides good adhesion to the electrolyte of the fuel cell, while the use of more electrode metal in the overlayer provides good electrical conductivity. The sintered fuel electrode is less expensive to produce compared with conventional electrodes made by electrochemical vapor deposition processes. The sintered electrodes exhibit favorable performance characteristics, including good porosity, adhesion, electrical conductivity and freedom from degradation. 4 figs.

  17. From agglomerates to aggregates by sintering coalescence

    E-print Network

    Daraio, Chiara

    1 From agglomerates to aggregates by sintering ­ coalescence Sotiris E. Pratsinis Particle by-products 5. Efficiency: Few and fast unit operations 2. Easier particle collection from gases than synthesis 1. No liquid by-products 5. Efficiency: Few and fast unit operations 2. Easier particle collection

  18. Sintered diamond compacts using metallic cobalt binders

    NASA Technical Reports Server (NTRS)

    Libby, W. F.; Katzman, H.

    1972-01-01

    Method is developed for sintering diamond powder which uses metallic cobalt as binder. Present samples show maximum microhardness of over 3000 kg/sq mm on Knoop scale. Material may be used as hard surface coating or may compete with cubic boron nitride as abrasive grain.

  19. Subsecond sintering of ice Denes Szaboa

    E-print Network

    phenomenon.1 It describes the formation of bonds between particles close to their melting point. Since ice on earth often exists close to its melting point, the sintering of ice has spe- cial importance. Many the pressure needed to change the melting point of ice far exceeds its mechanical strength. Except

  20. Sintering of Transparent Polycrystal Nd:YAG

    E-print Network

    Messing, Gary L.

    #12;PSU reactive sintering process Nd2O3-Al2O3 ball milling size Laser generation Patent JFCC & Polytechno Co. (Ikesue) Oxide powder from alkoxide - easy process should be reproducible, and robust - Large size without deformation or cracking (low shrinkage necessary

  1. Multistep sintering to synthesize fast lithium garnets

    NASA Astrophysics Data System (ADS)

    Xu, Biyi; Duan, Huanan; Xia, Wenhao; Guo, Yiping; Kang, Hongmei; Li, Hua; Liu, Hezhou

    2016-01-01

    A multistep sintering schedule is developed to synthesize Li7La3Zr2O12 (LLZO) doped with 0.2 mol% Al3+. The effect of sintering steps on phase, relative density and ionic conductivity of Al-doped LLZO has been evaluated using powder X-Ray diffraction (XRD), scanning electron microscopy (SEM), 27Al magic spinning nuclear magnetic resonance (NMR) spectroscopy and electrochemical impedance spectroscopy (EIS). The results show that by holding the sample at 900 °C for 6 h, the mixture of tetragonal and cubic garnet phases are obtained; by continuously holding at 1100 °C for 6 h, the tetragonal phase completely transforms into cubic phase; by holding at 1200 °C, the relative density increases without decomposition of the cubic phase. The Al-LLZO pellets after multistep sintering exhibit cubic phase, relative density of 94.25% and ionic conductivity of 4.5 × 10-4 S cm-1 at room temperature. Based on the observation, a sintering model is proposed and discussed.

  2. [Infrared Spectra Characteristics of the Silicate Nickel Ores: A Comparison Study on Different Ore Samples from Indonesia and China].

    PubMed

    Yang, Meng-li; Fu, Wei; Wang, Bao-hua; Zhang, Ya-qian; Huang, Xiao-rong; Niu, Hu-jie

    2015-03-01

    The silicate nickel ores developed in the lateritic nickel deposit, from Kolonodale, Sulawesi Island, Indonesia, and Yuanjiang, Yunnan province, China, were selected for the present study. The X-ray diffraction and Fourier infrared spectra were used to analyze the mineralogical attribute of laterite nickel ores from two different places. The results show that these two different silicate nickel ores have unique infrared spectra characteristics individually, which contributes to the ore classification. The silicate nickel ores from Kolonodale deposit, Indonesia, can be classified as the serpentine type, the montmorillonite + serpentine type, and the garnierite type. While, the silicate nickel ores from Yuanjiang deposit, China, can be classified as the serpentine type and the talc + serpentine type. Moreover, the mineral crystallinity of Yuanjiang nickel ores is generally better than Kolonodale nickel ores. According to the advantage of infrared absorption spectra in distinguishing mineral polytypes, it can be determined that lizardite is the main mineral type in the silicate nickel ores of the two deposits, and there is no obvious evidence of chrysotile and antigorite's existence. The characteristic of infrared absorption spectra also shows that frequency change of OH libration indicates Ni (Fe) replacing Mg in the serpentine type nickel-bearing mineral, that is, OH libration of serpentine moves to higher frequency, with the proportion of Ni (Fe) replacing Mg increasing. PMID:26117869

  3. Gold ore-forming fluids of the Tanami region, Northern Australia

    NASA Astrophysics Data System (ADS)

    Mernagh, Terrence P.; Wygralak, Andrew S.

    2007-01-01

    Fluid inclusion studies have been carried out on major gold deposits and prospects in the Tanami region to determine the compositions of the associated fluids and the processes responsible for gold mineralization. Pre-ore, milky quartz veins contain only two-phase aqueous inclusions with salinities ?19 wt% NaCl eq. and homogenization temperatures that range from 110 to 410°C. In contrast, the ore-bearing veins typically contain low to moderate salinity (<14 wt% NaCl eq.), H2O + CO2 ± CH4 ± N2-bearing fluids. The CO2-bearing inclusions coexist with two-phase aqueous inclusions that exhibit a wider range of salinities (?21 wt% NaCl eq.). Post-ore quartz and carbonate veins contain mainly two-phase aqueous inclusions, with a last generation of aqueous inclusions being very CaCl2-rich. Salinities range from 7 to 33 wt% NaCl eq. and homogenization temperatures vary from 62 to 312°C. Gold deposits in the Tanami region are hosted by carbonaceous or iron-rich sedimentary rocks and/or mafic rocks. They formed over a range of depths at temperatures from 200 to 430°C. The Groundrush deposit formed at the greatest temperatures and depths (260-430°C and ?11 km), whereas deposits in the Tanami goldfield formed at the lowest temperatures (?200°C) and at the shallowest depths (1.5-5.6 km). There is also evidence in the Tanami goldfield for late-stage isothermal mixing with higher salinity (?21 wt% NaCl eq.) fluids at temperatures between 100 and 200°C. Other deposits (e.g., The Granites, Callie, and Coyote) formed at intermediate depths and at temperatures ranging from 240 to 360°C. All ore fluids contained CO2 ± N2 ± CH4, with the more deeply formed deposits being enriched in CH4 and higher level deposits being enriched in CO2. Fluids from deposits hosted mainly by sedimentary rocks generally contained appreciable quantities of N2. The one exception is the Tanami goldfield, where the quartz veins were dominated by aqueous inclusions with rare CO2-bearing inclusions. Calculated ? 18O values for the ore fluids range from 3.8 to 8.5‰ and the corresponding ?D values range from -89 to -37‰. Measured ? 13C values from CO2 extracted from fluid inclusions ranged from -5.1 to -8.4‰. These data indicate a magmatic or mixed magmatic/metamorphic source for the ore fluids in the Tanami region. Interpretation of the fluid inclusion, alteration, and structural data suggests that mineralization may have occurred via a number of processes. Gold occurs in veins associated with brittle fracturing and other dilational structures, but in the larger deposits, there is also an association with iron-rich rocks or carbonaceous sediments, suggesting that both structural and chemical controls are important. The major mineralization process appears to be boiling/effervescence of a gas-rich fluid, which leads to partitioning of H2S into the vapor phase resulting in gold precipitation. However, some deposits also show evidence of desulfidation by fluid-rock interaction and/or reduction of the ore-fluid by fluid mixing. These latter processes are generally more prevalent in the higher crustal-level deposits.

  4. Microbiological and geochemical dynamics in simulated-heap leaching of a polymetallic sulfide ore.

    PubMed

    Wakeman, Kathryn; Auvinen, Hannele; Johnson, D Barrie

    2008-11-01

    The evolution of microbial populations involved in simulated-heap leaching of a polymetallic black schist sulfide ore (from the recently-commissioned Talvivaara mine, Finland) was monitored in aerated packed bed column reactors over a period of 40 weeks. The influence of ore particle size (2-6.5 mm and 6.5-12 mm) on changes in composition of the bioleaching microflora and mineral leaching dynamics in columns was investigated and compared to fine-grain (<2 microm) ore that was bioprocessed in shake flask cultures. Both column reactors and shake flasks were inoculated with 24 different species and strains of mineral-oxidizing and other acidophilic micro-organisms, and maintained at 37 degrees C. Mineral oxidation was most rapid in shake flask cultures, with about 80% of both manganese and nickel and 68% of zinc being leached within 6 weeks, though relatively little of the copper present in the ore was solubilised. The microbial consortium that emerged from the original inoculum was relatively simple in shake flasks, and was dominated by the iron-oxidizing autotroph Leptospirillum ferriphilum, with smaller numbers of Acidimicrobium ferrooxidans, Acidithiobacillus caldus and Leptospirillum ferrooxidans. Both metal recovery and (for the most part) total numbers of prokaryotes were greater in the column reactor containing the medium-grain than that containing the coarse-grain ore. The bioleaching communities in the columns displayed temporal changes in composition and differed radically from those in shake flask cultures. While iron-oxidizing chemoautotrophic bacteria were always the most numerically dominant bacteria in the medium-grain column bioreactor, there were major shifts in the most abundant species present, with the type strain of Acidithiobacillus ferrooxidans dominating in the early phase of the experiment and other bacteria (At. ferrooxidans NO37 and L. ferriphilum) dominating from week 4 to week 40. With the coarse-grain column bioreactor, similar transitions in populations of iron-oxidizing chemoautotrophs were observed, though heterotrophic acidophiles were often the most abundant bacteria found in mineral leach liquors. Four bacteria not included in the mixed culture used to inoculate the columns were detected by biomolecular techniques and three of these (all Alicyclobacillus-like Firmicutes) were isolated as pure cultures. The fourth bacterium, identified from a clone library, was related to the Gram-positive sulfate reducer Desulfotomaculum salinum. All four were considered to have been present as endospores on the dried ore, which was not sterilized in the column bioreactors. Two of the Alicyclobacillus-like isolates were found, transiently, in large numbers in mineral leachates. The data support the hypothesis that temporal and spatial heterogeneity in mineral heaps create conditions that favour different mineral-oxidizing microflora, and that it is therefore important that sufficient microbial diversity is present in heaps to optimize metal extraction. PMID:18496880

  5. Yttrium oxide transparent ceramics by low-temperature microwave sintering

    SciTech Connect

    Luo, Junming; Zhong, Zhenchen; Xu, Jilin

    2012-12-15

    Graphical abstract: The figure shows the SEM photos of the surfaces of the Y{sub 2}O{sub 3} transparent ceramic samples obtained by microwave sintering and vacuum sintering. It is clearly demonstrated that the grain distribution of the vacuum sintering sample is not uniform with the smallest and the largest particle size at about 2 ?m and 15 ?m respectively, while the grain distribution of microwave sintering sample is uniform with the average diameter at about 2–4 ?m (the smallest reported so far) and with no abnormal growth-up or coarsening phenomenon. We have further found out that the smaller the grain size, the higher the mechanical and optical properties. Display Omitted Highlights: ? The microwave sintering temperature of the sample is lower compared with vacuum. ? The microwave sintering time of the sample is shorter compared with vacuum. ? The mechanical properties of the microwave sintering sample is improved greatly. ? The Y{sub 2}O{sub 3} grain of microwave sintering sample is the smallest reported so far. -- Abstract: Yttrium oxide (Y{sub 2}O{sub 3}) transparent ceramics samples have been successfully fabricated by microwave sintering processing at relatively low temperatures. In comparison with the vacuum sintering processing, Y{sub 2}O{sub 3} transparent ceramics can be obtained by microwave sintering at lower sintering temperature and shorter sintering time, and they possess higher transmittances and mechanical properties. The technologies of low-temperature microwave sintering and the relationships of the microstructures and properties of the specified samples have been investigated in detail. We have found out that the low-temperature microwave sintering technique has its obvious advantages over the conventional methods in manufacturing yttrium oxide transparent ceramics.

  6. 40 CFR 440.50 - Applicability; description of the titanium ore subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Applicability; description of the titanium ore subcategory. 440.50 Section...AND DRESSING POINT SOURCE CATEGORY Titanium Ore Subcategory § 440.50 Applicability; description of the titanium ore subcategory. The...

  7. 40 CFR 440.50 - Applicability; description of the titanium ore subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Applicability; description of the titanium ore subcategory. 440.50 Section...AND DRESSING POINT SOURCE CATEGORY Titanium Ore Subcategory § 440.50 Applicability; description of the titanium ore subcategory. The...

  8. 40 CFR 440.50 - Applicability; description of the titanium ore subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Applicability; description of the titanium ore subcategory. 440.50 Section...AND DRESSING POINT SOURCE CATEGORY Titanium Ore Subcategory § 440.50 Applicability; description of the titanium ore subcategory. The...

  9. 40 CFR 440.50 - Applicability; description of the titanium ore subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Applicability; description of the titanium ore subcategory. 440.50 Section...AND DRESSING POINT SOURCE CATEGORY Titanium Ore Subcategory § 440.50 Applicability; description of the titanium ore subcategory. The...

  10. 40 CFR 440.50 - Applicability; description of the titanium ore subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Applicability; description of the titanium ore subcategory. 440.50 Section...AND DRESSING POINT SOURCE CATEGORY Titanium Ore Subcategory § 440.50 Applicability; description of the titanium ore subcategory. The...

  11. 40 CFR 440.110 - Applicability; description of the platinum ore subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Applicability; description of the platinum ore subcategory. 440.110 Section...AND DRESSING POINT SOURCE CATEGORY Platinum Ores Subcategory § 440.110 Applicability; description of the platinum ore subcategory. The...

  12. 40 CFR 440.110 - Applicability; description of the platinum ore subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Applicability; description of the platinum ore subcategory. 440.110 Section...AND DRESSING POINT SOURCE CATEGORY Platinum Ores Subcategory § 440.110 Applicability; description of the platinum ore subcategory. The...

  13. 40 CFR 440.110 - Applicability; description of the platinum ore subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Applicability; description of the platinum ore subcategory. 440.110 Section...AND DRESSING POINT SOURCE CATEGORY Platinum Ores Subcategory § 440.110 Applicability; description of the platinum ore subcategory. The...

  14. 40 CFR 440.110 - Applicability; description of the platinum ore subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Applicability; description of the platinum ore subcategory. 440.110 Section...AND DRESSING POINT SOURCE CATEGORY Platinum Ores Subcategory § 440.110 Applicability; description of the platinum ore subcategory. The...

  15. 40 CFR 440.110 - Applicability; description of the platinum ore subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Applicability; description of the platinum ore subcategory. 440.110 Section...AND DRESSING POINT SOURCE CATEGORY Platinum Ores Subcategory § 440.110 Applicability; description of the platinum ore subcategory. The...

  16. 40 CFR 440.30 - Applicability; description of the uranium, radium and vanadium ores subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Applicability; description of the uranium, radium and vanadium ores...STANDARDS (CONTINUED) ORE MINING AND DRESSING POINT SOURCE CATEGORY Uranium, Radium and Vanadium Ores...Applicability; description of the uranium, radium and vanadium...

  17. 40 CFR 440.30 - Applicability; description of the uranium, radium and vanadium ores subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Applicability; description of the uranium, radium and vanadium ores...GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Uranium, Radium and Vanadium Ores...Applicability; description of the uranium, radium and vanadium...

  18. 40 CFR 440.30 - Applicability; description of the uranium, radium and vanadium ores subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Applicability; description of the uranium, radium and vanadium ores...STANDARDS (CONTINUED) ORE MINING AND DRESSING POINT SOURCE CATEGORY Uranium, Radium and Vanadium Ores...Applicability; description of the uranium, radium and vanadium...

  19. 40 CFR 440.30 - Applicability; description of the uranium, radium and vanadium ores subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Applicability; description of the uranium, radium and vanadium ores...GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Uranium, Radium and Vanadium Ores...Applicability; description of the uranium, radium and vanadium...

  20. 40 CFR 440.30 - Applicability; description of the uranium, radium and vanadium ores subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Applicability; description of the uranium, radium and vanadium ores...STANDARDS (CONTINUED) ORE MINING AND DRESSING POINT SOURCE CATEGORY Uranium, Radium and Vanadium Ores...Applicability; description of the uranium, radium and vanadium...

  1. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Applicability; description of the mercury ore subcategory. 440.40 Section...AND DRESSING POINT SOURCE CATEGORY Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The...

  2. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Applicability; description of the mercury ore subcategory. 440.40 Section...AND DRESSING POINT SOURCE CATEGORY Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The...

  3. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Applicability; description of the mercury ore subcategory. 440.40 Section...AND DRESSING POINT SOURCE CATEGORY Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The...

  4. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Applicability; description of the mercury ore subcategory. 440.40 Section...AND DRESSING POINT SOURCE CATEGORY Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The...

  5. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Applicability; description of the mercury ore subcategory. 440.40 Section...AND DRESSING POINT SOURCE CATEGORY Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The...

  6. 40 CFR 440.80 - Applicability; description of the vanadium ore subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Applicability; description of the vanadium ore subcategory. 440.80 Section...MINING AND DRESSING POINT SOURCE CATEGORY Vanadium Ore Subcategory (Mined Alone and Not... Applicability; description of the vanadium ore subcategory. The...

  7. 40 CFR 440.80 - Applicability; description of the vanadium ore subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Applicability; description of the vanadium ore subcategory. 440.80 Section...MINING AND DRESSING POINT SOURCE CATEGORY Vanadium Ore Subcategory (Mined Alone and Not... Applicability; description of the vanadium ore subcategory. The...

  8. 40 CFR 440.80 - Applicability; description of the vanadium ore subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Applicability; description of the vanadium ore subcategory. 440.80 Section...MINING AND DRESSING POINT SOURCE CATEGORY Vanadium Ore Subcategory (Mined Alone and Not... Applicability; description of the vanadium ore subcategory. The...

  9. 40 CFR 440.80 - Applicability; description of the vanadium ore subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Applicability; description of the vanadium ore subcategory. 440.80 Section...MINING AND DRESSING POINT SOURCE CATEGORY Vanadium Ore Subcategory (Mined Alone and Not... Applicability; description of the vanadium ore subcategory. The...

  10. 40 CFR 440.80 - Applicability; description of the vanadium ore subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Applicability; description of the vanadium ore subcategory. 440.80 Section...MINING AND DRESSING POINT SOURCE CATEGORY Vanadium Ore Subcategory (Mined Alone and Not... Applicability; description of the vanadium ore subcategory. The...

  11. 40 CFR 440.70 - Applicability; description of the nickel ore subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Applicability; description of the nickel ore subcategory. 440.70 Section...MINING AND DRESSING POINT SOURCE CATEGORY Nickel Ore Subcategory § 440.70 Applicability; description of the nickel ore subcategory. The...

  12. 40 CFR 440.70 - Applicability; description of the nickel ore subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Applicability; description of the nickel ore subcategory. 440.70 Section...MINING AND DRESSING POINT SOURCE CATEGORY Nickel Ore Subcategory § 440.70 Applicability; description of the nickel ore subcategory. The...

  13. 40 CFR 440.70 - Applicability; description of the nickel ore subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Applicability; description of the nickel ore subcategory. 440.70 Section...MINING AND DRESSING POINT SOURCE CATEGORY Nickel Ore Subcategory § 440.70 Applicability; description of the nickel ore subcategory. The...

  14. 40 CFR 440.70 - Applicability; description of the nickel ore subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Applicability; description of the nickel ore subcategory. 440.70 Section...MINING AND DRESSING POINT SOURCE CATEGORY Nickel Ore Subcategory § 440.70 Applicability; description of the nickel ore subcategory. The...

  15. 40 CFR 440.70 - Applicability; description of the nickel ore subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Applicability; description of the nickel ore subcategory. 440.70 Section...MINING AND DRESSING POINT SOURCE CATEGORY Nickel Ore Subcategory § 440.70 Applicability; description of the nickel ore subcategory. The...

  16. Comparative sinterability of combustion synthesized and commercial titanium carbides

    SciTech Connect

    Manley, B.W.

    1984-11-01

    The influence of various parameters on the sinterability of combustion synthesized titanium carbide was investigaged. Titanium carbide powders, prepared by the combustion synthesis process, were sintered in the temperature range 1150 to 1600/sup 0/C. Incomplete combustion and high oxygen contents were found to be the cause of reduced shrinkage during sintering of the combustion syntheized powders when compared to the shrinkage of commercial TiC. Free carbon was shown to inhibit shrinkage. The activation energy for sintering was found to depend on stoichiometry (C/Ti). With decreasing C/Ti, the rate of sintering increased. 29 references, 16 figures, 13 tables.

  17. Pressureless sintering of whiskered-toughened ceramic composites

    DOEpatents

    Tiegs, T.N.

    1994-12-27

    A pressureless sintering method is disclosed for use in the production of whisker-toughened ceramic composites wherein the sintered density of composites containing up to about 20 vol. % SiC whiskers is improved by reducing the average aspect ratio of the whiskers to from about 10 to about 20. Sintering aids further improve the density, permitting the production of composites containing 20 vol. % SiC with sintered densities of 94% or better of theoretical density by a pressureless sintering method. 6 figures.

  18. Iron chelators and iron toxicity.

    PubMed

    Brittenham, Gary M

    2003-06-01

    Iron chelation may offer new approaches to the treatment and prevention of alcoholic liver disease. With chronic excess, either iron or alcohol alone may individually injure the liver and other organs. In combination, each exaggerates the adverse effects of the other. In alcoholic liver disease, both iron and alcohol contribute to the production of hepatic fibrosis through their effects on damaged hepatocytes, hepatic macrophages, hepatic stellate cells, and the extracellular matrix. The pivotal role of iron in these processes suggests that chelating iron may offer a new approach to arresting or ameliorating liver injury. For the past four decades, deferoxamine B mesylate has been the only iron-chelating agent generally available for clinical use. Clinical experience with deferoxamine has demonstrated the safety and effectiveness of iron chelation for the prevention and treatment of iron overload. Determined efforts to develop alternative agents have at last resulted in the development of a variety of candidate iron chelators that are now in or near clinical trial, including (a) the hexadentate phenolic aminocarboxylate HBED [N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid], (b) the tridentate desferrithiocin derivative 4'-OH-dadmDFT [4'-hydroxy-(S)-desazadesmethyl-desferrithiocin; (S)-4,5-dihydro-2-(2,4-dihydroxyphenyl)-4-thiazolecarboxylic acid], (c) the tridentate triazole ICL670A [CGP72 670A; 4-[3,5-bis-(hydroxyphenyl)-1,2,4-triazol-1-yl]-benzoic acid], and (d) the bidentate hydroxypyridin-4-one deferiprone [L1, CP20; 1,2-dimethyl-3-hydroxypyridin-4-one]. These agents may provide new pharmacological means of averting or ameliorating liver damage in alcoholic liver disease by binding, inactivating, and eliminating the reactive forms of iron that contribute to oxidative injury of cellular components, are involved in signal transduction, or both. PMID:12957300

  19. Chemical Sintering Generates Uniform Porous Hyaluronic Acid Hydrogels

    PubMed Central

    Cam, Cynthia; Segura, Tatiana

    2014-01-01

    Implantation of scaffolds for tissue repair has been met with limited success primarily due to the inability to achieve vascularization within the construct. Many strategies have shifted to incorporate pores into these scaffolds to encourage rapid cellular infiltration and subsequent vascular ingrowth. We utilized an efficient chemical sintering technique to create a uniform network of polymethyl methacrylate (PMMA) microspheres for porous hyaluronic acid hydrogel formation. The porous hydrogels generated from chemical sintering possessed comparable pore uniformity and interconnectivity as the commonly used non- and heat sintering techniques. Moreover, similar cell response to the porous hydrogels generated from each sintering approach was observed in cell viability, spreading, proliferation in vitro, as well as, cellular invasion in vivo. We propose chemical sintering of PMMA microspheres using a dilute acetone solution as an alternative method to generating porous hyaluronic acid hydrogels since it requires equal or ten-fold less processing time as the currently used non-sintering or heat sintering technique, respectively. PMID:24120847

  20. 15. NORTH ELEVATION OF UPPER ORE BIN, CHUTE, AND JAW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. NORTH ELEVATION OF UPPER ORE BIN, CHUTE, AND JAW CRUSHER, LOOKING SOUTH FROM END OF CONVEYOR PLATFORM. NOTICE THE THREE ORE BIN CONTROL DOORS, CORRESPONDING TO SEPARATE COMPARTMENTS OF THE BIN. - Skidoo Mine, Park Route 38 (Skidoo Road), Death Valley Junction, Inyo County, CA

  1. 39. HULETT ORE UNLOADER IN MOTION. VIEW LOOKING EAST. (Also ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    39. HULETT ORE UNLOADER IN MOTION. VIEW LOOKING EAST. (Also see OH-18-14, OH-18-38, and OH-18-40) - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  2. 40. HULETT ORE UNLOADER IN MOTION. VIEW LOOKING EAST. (Also ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. HULETT ORE UNLOADER IN MOTION. VIEW LOOKING EAST. (Also see OH-18-14, OH-18-38, and OH-18-39) - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  3. 19. VIEW OF CRUDE ORE BINS FROM EAST. EAST CRUDE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. VIEW OF CRUDE ORE BINS FROM EAST. EAST CRUDE ORE BIN IN FOREGROUND WITH DISCHARGE TO GRIZZLY AT BOTTOM OF VIEW. CONCRETE RETAINING WALL TO LEFT (SOUTH) AND BOTTOM (EAST EDGE OF EAST BIN). - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  4. 64. NORTH WALL OF CRUSHED OXIDIZED ORE BIN. THE PRIMARY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    64. NORTH WALL OF CRUSHED OXIDIZED ORE BIN. THE PRIMARY MILL FEEDS AT BOTTOM. MILL SOLUTION TANKS WERE TO THE LEFT (EAST) AND BARREN SOLUTION TANK TO THE RIGHT (WEST) OR THE CRUSHED ORE BIN. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  5. 25. INTERIOR VIEW LOOKING SOUTH IN THE ORE RECEIVING LEVEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. INTERIOR VIEW LOOKING SOUTH IN THE ORE RECEIVING LEVEL SHOWING THE TRAMWAY TRACKS IN THE FLOOR, ORE CHUTES IN THE FLOOR, NEWER TRACKS COMING IN FROM THE TRESTLE ON THE EAST SIDE OF THE MILL., AND THE WINDING DRUM THE TRAMWAY IN THE BACKGROUND. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  6. TRAM HOUSE INTERIOR, LOOKING SOUTHEAST. NOTE DEPARTING ORE BUCKET "12" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TRAM HOUSE INTERIOR, LOOKING SOUTHEAST. NOTE DEPARTING ORE BUCKET "12" AND SUSPENSION CABLE ANGLING DOWN THROUGH FLOOR AT LOWER LEFT. LARGE LEVER ON SIDE OF BUCKET ALLOWS IT TO BE ROTATED FOR DUMPING ORE. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  7. 24. REAR ELEVATION, HULETT ORE UNLOADERS. TRACKS CARRYING THE FRONT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. REAR ELEVATION, HULETT ORE UNLOADERS. TRACKS CARRYING THE FRONT END AND REAR LEGS OF THE HULETT UNLOADERS ARE LAID ON THE DOCK AND REAR WALLS, RESPECTIVELY; BOTH WALLS ARE MADE OF REINFORCED CONCRETE SUPPORTED ON CONCRETE PILES. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  8. 27. HULETT ORE UNLOADERS TEMPORARILY IN REPOSE, AS A NEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. HULETT ORE UNLOADERS TEMPORARILY IN REPOSE, AS A NEW SKIP TIES UP AT DOCK. THE UNLOADERS OPERATE ALMOST CONTINUOUSLY DURING THE SHIPPING SEASON, WHICH USUALLY RUNS FROM APRIL UNTIL LATE DECEMBER OR EARLY JANUARY. VIEW HERE IS LOOKING NORTHEAST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  9. The coupled geochemistry of Au and As in pyrite from hydrothermal ore deposits

    NASA Astrophysics Data System (ADS)

    Deditius, Artur P.; Reich, Martin; Kesler, Stephen E.; Utsunomiya, Satoshi; Chryssoulis, Stephen L.; Walshe, John; Ewing, Rodney C.

    2014-09-01

    The ubiquity of Au-bearing arsenian pyrite in hydrothermal ore deposits suggests that the coupled geochemical behaviour of Au and As in this sulfide occurs under a wide range of physico-chemical conditions. Despite significant advances in the last 20 years, fundamental factors controlling Au and As ratios in pyrite from ore deposits remain poorly known. Here we explore these constraints using new and previously published EMPA, LA-ICP-MS, SIMS, and ?-PIXE analyses of As and Au in pyrite from Carlin-type Au, epithermal Au, porphyry Cu, Cu-Au, and orogenic Au deposits, volcanogenic massive sulfide (VHMS), Witwatersrand Au, iron oxide copper gold (IOCG), and coal deposits. Pyrite included in the data compilation formed under temperatures from ?30 to ?600 °C and in a wide variety of geological environments. The pyrite Au-As data form a wedge-shaped zone in compositional space, and the fact that most data points plot below the solid solubility limit defined by Reich et al. (2005) indicate that Au1+ is the dominant form of Au in arsenian pyrite and that Au-bearing ore fluids that deposit this sulfide are mostly undersaturated with respect to native Au. The analytical data also show that the solid solubility limit of Au in arsenian pyrite defined by an Au/As ratio of 0.02 is independent of the geochemical environment of pyrite formation and rather depends on the crystal-chemical properties of pyrite and post-depositional alteration. Compilation of Au-As concentrations and formation temperatures for pyrite indicates that Au and As solubility in pyrite is retrograde; Au and As contents decrease as a function of increasing temperature from ?200 to ?500 °C. Based on these results, two major Au-As trends for Au-bearing arsenian pyrite from ore deposits are defined. One trend is formed by pyrites from Carlin-type and orogenic Au deposits where compositions are largely controlled by fluid-rock interactions and/or can be highly perturbed by changes in temperature and alteration by hydrothermal fluids. The second trend consists of pyrites from porphyry Cu and epithermal Au deposits, which are characterised by compositions that preserve the Au/As signature of mineralizing magmatic-hydrothermal fluids, confirming the role of this sulfide in controlling metal ratios in ore systems.

  10. Room Temperature Aging Study of Butyl O-rings

    SciTech Connect

    Mark Wilson

    2009-08-07

    During testing under the Enhanced Surveillance Campaign in 2001, preliminary data detected a previously unknown and potentially serious concern with recently procured butyl o-rings. All butyl o-rings molded from a proprietary formulation throughout the period circa 1999 through 2001 had less than a full cure. Tests showed that sealing force values for these suspect o-rings were much lower than expected and their physical properties were very sensitive to further post curing at elevated temperatures. Further testing confirmed that these o-rings were approximately 50% cured versus the typical industry standard of > 90% cured. Despite this condition, all suspect o-rings fully conformed to their QC acceptance requirements, including their individual product drawing requirements.

  11. Energy Consumption and Potential for Energy Conservation in the Steel Industry 

    E-print Network

    Hughes, M. L.

    1979-01-01

    PRIMARY CONVERSION HOT ROLLING FINISHING SIMPLIFIED FLOW SHEET STEEL PRODUCTION PROCESSES Iron Ore & Wastes , Agg lomerating Pellets Ore & Flux Coal ~ " Sinter - Blast ~ Coke Furnaces - Ovens '( BF Iron Outside ,~., Scrap Open... process there are three separate operations: blast furnaces, ore agglomerating facilities other than the mine-site preparation previously mentioned, and coke ovens -- the blast furnaces being the central production unit where the ore reduction...

  12. Study of Organic and Inorganic Binders on Strength of Iron Oxide Pellets

    NASA Astrophysics Data System (ADS)

    Srivastava, Urvashi; Kawatra, S. Komar; Eisele, Timothy C.

    2013-08-01

    Bentonite is a predominant binder used in iron ore pelletization. However, the presence of a high content of silica and alumina in bentonite is considered undesirable for ironmaking operations. The objective of this study was to identify the alternatives of bentonite for iron ore pelletization. To achieve this goal, different types of organic and inorganic binders were utilized to produce iron oxide pellets. The quality of these iron oxide pellets was compared with pellets made using bentonite. All pellets were tested for physical strength at different stages of pelletization to determine their ability to survive during shipping and handling. The results show that organic binders such as lactose monohydrate, hemicellulose, and sodium lignosulfonate can provide sufficient strength to indurated pellets.

  13. The use of coal in a solid phase reduction of iron oxide

    NASA Astrophysics Data System (ADS)

    Nokhrina, O. I.; Rozhihina, I. D.; Hodosov, I. E.

    2015-09-01

    The results of the research process of producing metalized products by solid-phase reduction of iron using solid carbonaceous reducing agents. Thermodynamic modeling was carried out on the model of the unit the Fe-C-O and system with iron ore and coal. As a result of modeling the thermodynamic boundary reducing, oxidizing, and transition areas and the value of the ratio of carbon and oxygen in the system. Simulation of real systems carried out with the gas phase obtained in the pyrolys of coal. The simulation results allow to determine the optimal cost of coal required for complete reduction of iron ore from a given composition. The kinetics of the processes of solid-phase reduction of iron using coal of various technological brands.

  14. Development of fluidized bed cement sintering technology

    SciTech Connect

    Mukai, Katsuji

    1994-12-31

    In the new system presented in this paper, the cement clinker is sintered, not in a rotary kiln, but in two different furnaces: a spouted bed kiln and a fluidized bed kiln. The heat generated in the process of cooling the cement clinker is recovered by a fluidized bed cooler and a packed bed cooler, which are more efficient than the conventional coolers. Compared with the rotary kiln system, the new technology significantly reduces NO{sub x} emissions, appreciably cuts energy consumption, and reduces CO{sub 2} emissions as well. Thus, the new system is an efficient cement sintering system that is friendly to the global environment. In this paper, we describe this new technology as one of the applied technologies at an industrial level that is being developed in the Clean Coal Technology Project, and we present the results from test operations at our pilot plant.

  15. Sintering aid for lanthanum chromite refractories

    DOEpatents

    Flandermeyer, Brian K. (Bolingbrook, IL); Poeppel, Roger B. (Glen Ellyn, IL); Dusek, Joseph T. (Downers Grove, IL); Anderson, Harlan U. (Rolla, MO)

    1988-01-01

    An electronically conductive interconnect layer for use in a fuel cell or other electrolytic device is formed with sintering additives to permit densification in a monolithic structure with the electrode materials. Additions including an oxide of boron and a eutectic forming composition of Group 2A metal fluorides with Group 3B metal fluorides and Group 2A metal oxides with Group 6B metal oxides lower the required firing temperature of lanthanum chromite to permit densification to in excess of 94% of theoretical density without degradation of electrode material lamina. The monolithic structure is formed by tape casting thin layers of electrode, interconnect and electrolyte materials and sintering the green lamina together under common densification conditions.

  16. Development of Continuous, Direct Feedback Control Systems for Sintering of Metallic Components

    SciTech Connect

    Diran Apelian; Marc M. Baum

    2006-09-18

    N,N.-Ethylenebisstearimide (EBS) is one of the most commonlyused lubricants in the powder metallurgy (PM) industry in the sintering process. During sintering, the lubricated powder compacts are heat-treated to temperatures in excess of 1,200 °C thus fusing adjacent particles and yielding a part with improved mechanical strength. Delubrication commonly is achieved in the first zone of a sintering furnace by heating the part to temperatures in the 500-600 °C temperature range at a fixed rate and under controlled atmospheric conditions; this strategy minimizes defects, carbon contamination, and compact deformation. The de-lubricated part then enters the second zone (commonly in the 1200-1300 °C temperature range) for sintering. The third zone cools the sintered part at a desired rate to obtain the requisite micro-structural properties. Controlled delubrication is imperative towards achieving high quality parts for the following reasons: the elevated thermal gradient at the transition between the first and second zones can cause parts to expand rapidly and develop microscopic fissures (.blistering.); improper gas flows and belt speeds can lead to carbon deposition on the part and at the grain boundaries (sooting); delubrication products deposit throughout the furnace, even in the coolers, which are far removed from the preheating chamber, leading to significant maintenance costs; pollutants emitted in the exhaust stream of furnaces operating inefficiently are increasingly of environmental concern. In practice, lubricant removal is difficult to control, which often leads to reduced yields in PM manufacturing processes. Throughput is another important issue: process control ideally should lead to a delubrication cycle that yields defect-free parts in a minimum of furnace time, thereby increasing productivity and reducing the net energy consumption. Efficient process control requires rapid monitoring of suitable indicators, preferably gasphase products of delubrication. EBS thermolyzes relatively cleanly in a range of furnace atmospheres, but the mechanism governing the pyrolysis of EBS, compacted with iron powder, is not known and needs to be investigated to determine the parameters important for industrial control, as well as the optimal conditions of delubrication. In addition, a thorough understanding of the pre-sintering chemistry will enable the development of a process control sensor.

  17. Constraints on the composition of ore fluids and implications for mineralising events at the Cleo gold deposit, Eastern Goldfields Province, Western Australia

    USGS Publications Warehouse

    Brown, S.M.; Johnson, C.A.; Watling, R.J.; Premo, W.R.

    2003-01-01

    The Cleo gold deposit, 55 km south of Laverton in the Eastern Goldfields Province of Western Australia, is characterised by banded iron-formation (BIF)-hosted ore zones in the gently dipping Sunrise Shear Zone and high-grade vein-hosted ore in the Western Lodes. There is evidence that gold mineralisation in the Western Lodes (which occurred at ca 2655 Ma) post-dates the majority of displacement along the Sunrise Shear Zone, but it remains uncertain if the ore in both structures formed simultaneously or separately. Overall, the Pb, Nd, Sr, C. O and S isotopic compositions of ore-related minerals from both the Western Lodes and ore zones in the Sunrise Shear Zone are similar. Early low-salinity aqueous-carbonic fluids and late high-salinity fluids with similar characteristics are trapped in inclusions in quartz veins from both the Sunrise Shear Zone and the Western Lodes. The early CO2, CO2-H2O, and H2O- dominant inclusions are interpreted as being related to ore formation, and to have formed from a single low-salinity aqueous-carbonic fluid as a result of intermittent fluid immiscibility. Homogenisation temperatures indicate that these inclusions were trapped at approximately 280??C and at approximately 4 km depth, in the deeper epizonal range. Differences between the ore zones are detected in the trace-element composition of gold samples, with gold from the Sunrise Shear Zone enriched in Ni, Pb, Sn, Te and Zn, and depleted In As, Bi, Cd, Cu and Sb, relative to gold from the Western Lodes. Although there are differences in gold composition between the Sunrise Shear Zone and Western Lodes, and hence the metal content of ore fluids may have varied slightly between the different ore zones, no other systematic fluid or solute differences are detected between the ore zones. Given the fact that the ore fluids in each zone have very similar bulk properties, the considerable differences in gold grade, sulfide mineral abundance, and ore textures between the two ore zones most likely result from different gold-deposition mechanisms. The association of ore zones in the Sunrise Shear Zone with pyrite-replaced BIF suggests that wall-rock sulfidation was the most significant mechanism of gold precipitation, through the destabilisation of gold-bisulfide complexes. The Western Lodes, however, do not exhibit any host-rock preference and multistage veins commonly contain coarse-grained gold. Fluid-inclusion characteristics and breccia textures in veins in the Western Lodes suggest that rapid pressure changes, brought about by intermittent release of overpressured fluids and concomitant phase separation, are likely to have caused the destabilisation of gold-thiocomplexes, leading to formation of higher-grade gold ore zones.

  18. Sintering and ripening resistant noble metal nanostructures

    DOEpatents

    van Swol, Frank B; Song, Yujiang; Shelnutt, John A; Miller, James E; Challa, Sivakumar R

    2013-09-24

    Durable porous metal nanostructures comprising thin metal nanosheets that are metastable under some conditions that commonly produce rapid reduction in surface area due to sintering and/or Ostwald ripening. The invention further comprises the method for making such durable porous metal nanostructures. Durable, high-surface area nanostructures result from the formation of persistent durable holes or pores in metal nanosheets formed from dendritic nanosheets.

  19. The Klyuchevskoe gold ore deposit (Eastern Transbaikalia): Formation conditions and petrogeochemical features of rocks and ores

    NASA Astrophysics Data System (ADS)

    Abramov, B. N.

    2015-09-01

    It was found that the magma chambers in the Amudzhikan complex (J3) were characterized by close degrees of their differentiation and occurred at depths corresponding to the lower continental crust. The formation of explosive breccias proceeded during each period of the ore-forming process. The magma chambers of early breccias occurred at great depths. The late breccias contain carbonate cement and are characterized by an increased REE content.

  20. Total Ore Processing Integration and Management

    SciTech Connect

    Leslie Gertsch; Richard Gertsch

    2006-01-30

    This report outlines the technical progress achieved for project DE-FC26-03NT41785 (Total Ore Processing Integration and Management) during the period 01 July through 30 September of 2005. This ninth quarterly report discusses the activities of the project team during the period 1 July through 30 September 2005. Richard Gertsch's unexpected death due to natural causes while in Minnesota to work on this project has temporarily slowed progress. Statistical analysis of the Minntac Mine data set for late 2004 is continuing. Preliminary results raised several questions that could be amenable to further study. Detailed geotechnical characterization is being applied to improve the predictability of mill and agglomerator performance at Hibtac Mine.

  1. After more than a century, iron sponge still soaks up hydrogen sulfide problems

    SciTech Connect

    Anerousis, J.P. )

    1994-09-01

    The oldest and simplest method for removing H[sub 2]S and other sulfur compounds, such as mercaptans, from gaseous streams is the iron sponge process. The basic technique consists of passing a sour gas stream (one containing H[sub 2]S or mercaptans, or both) across a bed of hydrated iron oxide. The chemical reaction produces iron sulfide and a small amount of by-product water. Although not a common practice, the spent material may be regenerated by exposing it to oxygen, which converts the mixed iron sulfides to their original iron oxide form. The iron sponge technique originated in Europe more than 100 years ago, and the earliest operators used a naturally occurring form of hydrated iron oxide known as bog iron or bog ore. As refinements were made in the process, it was found that more efficient sulfur removal could be attained by uniformly distributing the iron oxide hydrate across a substrate, and that active iron oxide could be prepared synthetically. Continual improvements in the synthetic iron sponge's composition focused on such issues as the crystalline forms of the hydrated iron oxide, size distribution of the active iron oxide particulates, overall chemical composition, size and nature of the typical wood substrate, moisture content, and degree of buffering. Modern iron sponge products are prepared with careful attention to each of these issues. The synthetic materials are characterized by high quality and uniform composition, and their overall characteristics optimize performance in typical gas-sweetening applications.

  2. Thermoelectric Coolers with Sintered Silver Interconnects

    NASA Astrophysics Data System (ADS)

    Kähler, Julian; Stranz, Andrej; Waag, Andreas; Peiner, Erwin

    2014-06-01

    The fabrication and performance of a sintered Peltier cooler (SPC) based on bismuth telluride with sintered silver interconnects are described. Miniature SPC modules with a footprint of 20 mm2 were assembled using pick-and-place pressure-assisted silver sintering at low pressure (5.5 N/mm2) and moderate temperature (250°C to 270°C). A modified flip-chip bonder combined with screen/stencil printing for paste transfer was used for the pick-and-place process, enabling high positioning accuracy, easy handling of the tiny bismuth telluride pellets, and immediate visual process control. A specific contact resistance of (1.4 ± 0.1) × 10-5 ? cm2 was found, which is in the range of values reported for high-temperature solder interconnects of bismuth telluride pellets. The realized SPCs were evaluated from room temperature to 300°C, considerably outperforming the operating temperature range of standard commercial Peltier coolers. Temperature cycling capability was investigated from 100°C to 235°C over more than 200 h, i.e., 850 cycles, during which no degradation of module resistance or cooling performance occurred.

  3. Liquid phase sintered compacts in space

    NASA Technical Reports Server (NTRS)

    Mookherji, T. K.; Mcanelly, W. B.

    1974-01-01

    A model that will explain the effect of gravity on liquid phase sintering was developed. Wetting characteristics and density segregation which are the two important phenomena in liquid phase sintering are considered in the model development. Experiments were conducted on some selected material combinations to study the gravity effects on liquid phase sintering, and to verify the validity of the model. It is concluded that: (1) The surface tension forces acting on solid particles in a one-g environment are not appreciably different from those anticipated in a 0.00001g/g sub 0 (or lower) environment. (2) The capillary forces are dependent on the contact angle, the quantity of the liquid phase, and the distance between solid particles. (3) The pores (i.e., bubbles) do not appear to be driven to the surface by gravity-produced buoyancy forces. (4) The length of time to produce the same degree of settling in a low-gravity environment will be increased significantly. (5) A low gravity environment would appear to offer a unique means of satisfactorily infiltrating a larger and/or complex shaped compact.

  4. Ceramic Interconnects with Low Sintering Temperature

    NASA Technical Reports Server (NTRS)

    Zhong, Zhi-Min; Goldsby, Jon C.

    2004-01-01

    Ceramic interconnects for use in solid oxide he1 cells are expected to operate between 900 to approximately 1000 C, sinter below 1400 C to allow co-firing and meet a number thermal mechanical requirements. The pervoskite type (ABO3) lanthanum chromite based materials have emerged as a leading candidate that will meet these criteria by varying the composition on the A and B sites. A need therefore exists to determine this material's temperature dependent electrical and mechanical properties with respect to these site substitutions. In this investigation oxide powders were prepared by the glycine-nitrate process. Ionic substitutions were carried out on A sites with Ca or Sr, and B sites with Co and Al, respectively. Only stoichiometric compositions were considered for the sake of stability. The powders and their ability to sinter were investigated by XRD, SEM, dilatometry and density measurements. The sintered materials were further examined by SEM, thermal expansion and electric conductivity measurements in order to elucidate the resulting microstructure, electrical and mechanical properties. In addition quantum mechanical calculations were performed to obtain insight into the effects of these dopants on the materials electronic band structure and lattice parameter.

  5. Preservation of Microbial Lipids in Geothermal Sinters

    NASA Astrophysics Data System (ADS)

    Kaur, Gurpreet; Mountain, Bruce W.; Hopmans, Ellen C.; Pancost, Richard D.

    2011-04-01

    Lipid biomarkers are widely used to study the earliest life on Earth and have been invoked as potential astrobiological markers, but few studies have assessed their survival and persistence in geothermal settings. Here, we investigate lipid preservation in active and inactive geothermal silica sinters, with ages of up to 900 years, from Champagne Pool, Waiotapu, New Zealand. Analyses revealed a wide range of bacterial biomarkers, including free and bound fatty acids, 1,2-di-O-alkylglycerols (diethers), and various hopanoids. Dominant archaeal lipids include archaeol and glycerol dialkyl glycerol tetraethers (GDGTs). The predominance of generally similar biomarker groups in all sinters suggests a stable microbial community throughout Champagne Pool's history and indicates that incorporated lipids can be well preserved. Moreover, subtle differences in lipid distributions suggest that past changes in environmental conditions can be elucidated. In this case, higher archaeol abundances relative to the bacterial diethers, a greater proportion of cyclic GDGTs, the high average chain length of the bacterial diethers, and greater concentrations of hopanoic acids in the older sinters all suggest hotter conditions at Champagne Pool in the past.

  6. CFB roasting for gold ore processing

    SciTech Connect

    Hubbard, G.; D'Acierno, J.P.

    1999-07-01

    This paper describes how KTI/Dorr-Oliver applied the results from CFB boiler technology to the design for a CFB mineral processing plant built in Africa in 1992. The whole ore gold roaster plant located in Syama, Mali is presently owned and operated by Randgold of South Africa and it processes over 216 tons per hour of whole gold ore. The plant has operated continuously for over four years. The CFB reactor operates in the turbulent CFB mode of fluidization with over 40 minutes of solids residence time in the dense phase for optimum conversion of the feed material. The success of the plant after four years of operation is in large part due to the choice of the turbulent CFB mode of fluidization. This mode is very flexible in face of significant variations in feed composition and size distribution. Sulfur capture takes place in situ and the sorbent is present naturally in the feed. An electrostatic precipitator is used for particulate removal from the flue gas. The energy balance for the system requires auxiliary fuel oil burned in the CFB reactor. Energy from the 1,200--1,350 F roasted product stream is recovered and recycled back into the CFB using two fluidized bed coolers; one to directly heat the secondary air and the other to indirectly heat the primary fluidizing air. Pilot plant testing and the scale up of pilot plant results to the full scale plant is described. The plant start up including resolution of some unique start up difficulties is covered. A comparison of results for the pilot plant and commercial plant is presented.

  7. Ore minerals textural characterization by hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Bonifazi, Giuseppe; Picone, Nicoletta; Serranti, Silvia

    2013-02-01

    The utilization of hyperspectral detection devices, for natural resources mapping/exploitation through remote sensing techniques, dates back to the early 1970s. From the first devices utilizing a one-dimensional profile spectrometer, HyperSpectral Imaging (HSI) devices have been developed. Thus, from specific-customized devices, originally developed by Governmental Agencies (e.g. NASA, specialized research labs, etc.), a lot of HSI based equipment are today available at commercial level. Parallel to this huge increase of hyperspectral systems development/manufacturing, addressed to airborne application, a strong increase also occurred in developing HSI based devices for "ground" utilization that is sensing units able to play inside a laboratory, a processing plant and/or in an open field. Thanks to this diffusion more and more applications have been developed and tested in this last years also in the materials sectors. Such an approach, when successful, is quite challenging being usually reliable, robust and characterised by lower costs if compared with those usually associated to commonly applied analytical off- and/or on-line analytical approaches. In this paper such an approach is presented with reference to ore minerals characterization. According to the different phases and stages of ore minerals and products characterization, and starting from the analyses of the detected hyperspectral firms, it is possible to derive useful information about mineral flow stream properties and their physical-chemical attributes. This last aspect can be utilized to define innovative process mineralogy strategies and to implement on-line procedures at processing level. The present study discusses the effects related to the adoption of different hardware configurations, the utilization of different logics to perform the analysis and the selection of different algorithms according to the different characterization, inspection and quality control actions to apply.

  8. Alteration mineral mapping for iron prospecting using ETM+ data, Tonkolili iron field, northern Sierra Leone

    NASA Astrophysics Data System (ADS)

    Mansaray, Lamin R.; Liu, Lei; Zhou, Jun; Ma, Zhimin

    2013-10-01

    The Tonkolili iron field in northern Sierra Leone has the largest known iron ore deposit in Africa. It occurs in a greenstone belt in an Achaean granitic basement. This study focused mainly on mapping areas with iron-oxide and hydroxyl bearing minerals, and identifying potential areas for haematite mineralization and banded iron formations (BIFs) in Tonkolili. The predominant mineral assemblage at the surface (laterite duricrust) of this iron field is haematitegoethite- limonite ±magnetite. The mineralization occurs in quartzitic banded ironstones, layered amphibolites, granites, schists and hornblendites. In this study, Crosta techniques were applied on Enhanced Thematic Mapper (ETM+) data to enhance areas with alteration minerals and target potential areas of haematite and BIF units in the Tonkolili iron field. Synthetic analysis shows that alteration zones mapped herein are consistent with the already discovered magnetite BIFs in Tonkolili. Based on the overlaps of the simplified geological map and the remote sensing-based alteration mineral maps obtained in this study, three new haematite prospects were inferred within, and one new haematite prospect was inferred outside the tenement boundary of the Tonkolili exploration license. As the primary iron mineral in Tonkolili is magnetite, the study concludes that, these haematite prospects could also be underlain by magnetite BIFs. This study also concludes that, the application of Crosta techniques on ETM+ data is effective not only in mapping iron-oxide and hydroxyl alterations but can also provide a basis for inferring areas of potential iron resources in Algoma-type banded iron formations (BIFs), such as those in the Tonkolili field.

  9. Microwave treatment of a brown coal concentrate from Mugunsk coal for the manufacture of sponge iron

    SciTech Connect

    A.A. Khaidurova; P.N. Konovalov; N.P. Konovalov

    2008-04-15

    A technique for the production of a finely dispersed dry brown coal concentrate with the use of microwave energy is proposed to prepare a charge mixture for the manufacture of sponge iron. The advantages of this technique over analogous industrial processes are demonstrated. The results of experiments on the briquetting of the charge mixture of brown coal and iron ore concentrates without the use of an additional binding agent are described.

  10. Sintered Bismuth Telluride Alloys for Thermoelectric Generators.

    NASA Astrophysics Data System (ADS)

    Situmorang, Marhaposan

    A new technique has been developed for promoting texture in cold-pressed sintered bismuth telluride alloys, since it is known that the figure of merit of sintered samples with completely random orientation has a lower value than in single crystals. The technique includes the arrangement of the plate-like shaped powders in a dielectric liquid in a controlled manner using an electrodispersion technique. The plate-like shaped powders were obtained from well aligned directionally frozen ingots which were crushed by turning on a lathe. Partly oriented sintered samples were produced which are suitable for a use in thermoelectric generators that operate between room temperature and up to 200^circC. Suitable dopants were also selected to give a good figure of merit in that temperature range of operation. The degree of orientation in the partly oriented samples was determined using an X-ray diffraction method and also by measuring the Seebeck coefficient in the intrinsic region of conduction. The results from the two methods are found to be consistent with one another if one assumes a structural model that is intermediate between those of the thin disc and the long bar. The figure of merit of the partly oriented samples was found to be lower than the expected value, the degradation being more pronounced in the n-type samples. It was, therefore, considered that the lack of orientation is not the only factor that reduces the figure of merit, especially in the n-type samples. Other problems such as oxidation effects, inter-grain boundary contacts and the effect of inhomogeneity are also likely to reduce the figure of merit. Attempts were made to minimize these effects by reducing the time lapse between grinding and pressing, by repressing and resintering of the samples after initial pressing and sintering, prolonged the sintering time, etc. Various samples with different values of figure of merit were obtained according to their composition and their processing techniques. The samples with a high figure of merit were selected to be used in a generator. The efficiency of the generator was determined in vacuum up to a temperature difference of 147^circC. The efficiency at this temperature difference was 5.6%, which was close to the theoretical prediction.

  11. Plasma-activated sintering (PAS) - A new consolidation method for difficult-to-sinter materials

    NASA Astrophysics Data System (ADS)

    Hensley, Jonathan, Jr.; Shan, Chien H.; Risbud, Subhash H.; Groza, Joanna R.

    Plasma-activated sintering (PAS) is a novel powder consolidation method that densifies materials in a very short time at high temperature in a high current discharge. We assume that the application of instantaneous pulsed electric power activates the particle surface and this surface activation contributes to enhanced sintering due to the 'in-situ' cleaning of particle surfaces and concentrated heating. The accelerated densification in PAS is also attributed to the effects of subsequent resistance heating and pressure application. We summarize examples of the PAS consolidation process as applied to difficult-to-sinter powder materials, such as covalent, additive-free AlN, Nb3Al, and superconducting (Bi(1.7),Pb(0.3))Sr2Ca(2.1)Cu(3.1)O(x) ceramics. The absence of significant grain growth during the densification process and related microstructural benefits of PAS processing are highlighted.

  12. Radon emanation from low-grade uranium ore.

    PubMed

    Sahu, Patitapaban; Mishra, Devi Prasad; Panigrahi, Durga Charan; Jha, Vivekanand; Patnaik, R Lokeswara

    2013-12-01

    Estimation of radon emanation in uranium mines is given top priority to minimize the risk of inhalation exposure due to short-lived radon progeny. This paper describes the radon emanation studies conducted in the laboratory as well as inside an operating underground uranium mine at Jaduguda, India. Some of the important parameters, such as grade/(226)Ra activity, moisture content, bulk density, porosity and emanation fraction of ore, governing the migration of radon through the ore were determined. Emanation from the ore samples in terms of emanation rate and emanation fraction was measured in the laboratory under airtight condition in glass jar. The in situ radon emanation rate inside the mine was measured from drill holes made in the ore body. The in situ(222)Rn emanation rate from the mine walls varied in the range of 0.22-51.84 × 10(-3) Bq m(-2) s(-1) with the geometric mean of 8.68 × 10(-3) Bq m(-2) s(-1). A significant positive linear correlation (r = 0.99, p < 0.001) between in situ(222)Rn emanation rate and the ore grade was observed. The emanation fraction of the ore samples, which varied in the range of 0.004-0.089 with mean value of 0.025 ± 0.02, showed poor correlation with ore grade and porosity. Empirical relationships between radon emanation rate and the ore grade/(226)Ra were also established for quick prediction of radon emanation rate from the ore body. PMID:23974076

  13. Optimization of sinter/HIP parameters of multiphase silicon nitride/silicon carbide ceramics

    SciTech Connect

    Perera, D.S.; Moricca, S.; Drennan, J.; Fan, Q.S.; Gu, P.Z.

    1996-12-31

    Multiphase silicon carbide reinforced silicon nitride materials were sintered using 3 techniques, (1) pressureless sintering, (2) post-sinter HIPing and (3) sintering and HIPing in the same cycle (sinter/HIP). The materials have been characterized with respect to their microstructure, phase relationships and mechanical properties. The materials reached almost the theoretical density using the 3 sintering methods, but this was achieved at a lower temperature with sinter/HIPing. A balance should be sought between the high pressure required for high density and the prevention of excessive nitrogen (pressurizing gas) dissolution in the glassy grain boundary phases. The optimization of sinter/HIP parameters are discussed with respect to sintering mechanisms.

  14. Iron Chelation Therapy

    MedlinePLUS

    ... iron overload. What actually happens to cause iron overload? With each red blood cell transfusion, your body ... is deposited. What are the symptoms of iron overload? Early on, iron overload can cause no symptoms, ...

  15. 36. INTERIOR VIEW LOOKING WEST FROM UNDERNEATH THE ORE BINS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. INTERIOR VIEW LOOKING WEST FROM UNDERNEATH THE ORE BINS LOOKING AT THE BACK SIDE OF THE HENDY CHALLENGE CONTINUOUS ORE FEEDERS, #1 IS ON THE LEFT, #2 IS CENTER, AND #3 IS ON THE RIGHT. THESE ARE USED TO KEEP A CONTINUOUS FLOW OF ORE INTO THE STAMP MILLS. NOTE THE SPARE FEEDER DISKS ON THE FLOOR BOTTOM CENTER AND SPARE STAMP HEADS AND SHOES ON THE FLOOR BOTTOM LEFT OF THE IMAGE. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  16. Tourmaline as a recorder of ore-forming processes

    USGS Publications Warehouse

    Slack, J.F.; Trumbull, R.B.

    2011-01-01

    Tourmaline occurs in diverse types of hydrothermal mineral deposits and can be used to constrain the nature and evolution of ore-forming fl uids. Because of its broad range in composition and retention of chemical and isotopic signatures, tourmaline may be the only robust recorder of original mineralizing processes in some deposits. Microtextures and in situ analysis of compositional and isotopic variations in ore-related tourmaline provide valuable insights into hydrothermal systems in seafl oor, sedimentary, magmatic, and metamorphic environments. Deciphering the hydrothermal record in tourmaline also holds promise for aiding exploration programs in the search for new ore deposits.

  17. Accelerated sintering in phase-separating nanostructured alloys.

    PubMed

    Park, Mansoo; Schuh, Christopher A

    2015-01-01

    Sintering of powders is a common means of producing bulk materials when melt casting is impossible or does not achieve a desired microstructure, and has long been pursued for nanocrystalline materials in particular. Acceleration of sintering is desirable to lower processing temperatures and times, and thus to limit undesirable microstructure evolution. Here we show that markedly enhanced sintering is possible in some nanocrystalline alloys. In a nanostructured W-Cr alloy, sintering sets on at a very low temperature that is commensurate with phase separation to form a Cr-rich phase with a nanoscale arrangement that supports rapid diffusional transport. The method permits bulk full density specimens with nanoscale grains, produced during a sintering cycle involving no applied stress. We further show that such accelerated sintering can be evoked by design in other nanocrystalline alloys, opening the door to a variety of nanostructured bulk materials processed in arbitrary shapes from powder inputs. PMID:25901420

  18. Sinterability, strength and oxidation of alpha silicon carbide powders

    NASA Technical Reports Server (NTRS)

    Dutta, S.

    1984-01-01

    An investigation is made of pressureless sintering of commercially available alpha-SiC powders at temperatures between 1900 and 2150 C for periods of 10 to 240 min under one atmosphere of argon pressure. It is found that alpha-SiC powder containing boron and carbon sintering aids is sinterable at 2150 C for a period of 30 min to a high final density (greater than 96 percent of theoretical). In alpha-SiC powder containing aluminum and carbon sintering aids, the final density achieved is only about 80 percent of theoretical. Determinations are made of room temperature and high temperature (1370 C) flexure strength and oxidation resistance on sintered high density (more than 96 percent of theoretical) alpha-SiC (boron, carbon) material. It is found that both the strength and the resistance to oxidation are equivalent and comparable to those of the sintered alpha-SiC which represents the state of the art.

  19. Accelerated sintering in phase-separating nanostructured alloys

    PubMed Central

    Park, Mansoo; Schuh, Christopher A.

    2015-01-01

    Sintering of powders is a common means of producing bulk materials when melt casting is impossible or does not achieve a desired microstructure, and has long been pursued for nanocrystalline materials in particular. Acceleration of sintering is desirable to lower processing temperatures and times, and thus to limit undesirable microstructure evolution. Here we show that markedly enhanced sintering is possible in some nanocrystalline alloys. In a nanostructured W–Cr alloy, sintering sets on at a very low temperature that is commensurate with phase separation to form a Cr-rich phase with a nanoscale arrangement that supports rapid diffusional transport. The method permits bulk full density specimens with nanoscale grains, produced during a sintering cycle involving no applied stress. We further show that such accelerated sintering can be evoked by design in other nanocrystalline alloys, opening the door to a variety of nanostructured bulk materials processed in arbitrary shapes from powder inputs. PMID:25901420

  20. Enhancing microbial iron reduction in hyperalkaline, chromium contaminated sediments by pH amendment

    E-print Network

    Burke, Ian

    Enhancing microbial iron reduction in hyperalkaline, chromium contaminated sediments by p.2). Chromium was found to have accumulated in this soil as a result of an abiotic reaction of Cr(VI) with Fe; Deakin et al., 2001; Stewart et al., 2010). Chromium is extracted from its ore, chromite, by roasting