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Study on Reasonable Mineral Processing Flow Sheet of Yunfu Low-Grade Pyrite Ores Low-grade ores in Yunfu Pyrite Mining Area were investigated, in order to find an economical, reasonable and environment-friendly mineral processing technology, which is of low consumption and high efficiency in pyrite recovering, which can ensure that the quality of pyrite concentrate product is eligible for sale and the sulfur content of the discharged tailings meets the national emission standards. A flow sheet with a classification, a jigging for coarse-grain minerals and a spiral chute separation for fine-grained minerals was adopted, and the sulfur grade and recovery of the pyrite concentrate is 35.50 per cent and 86.70 per cent respectively, while the grade of tailings is only 6.70 per cent.

Sep 13, 2010

By J. S. Pascover, S. V. Radcliffe

The structures and transformation temperatures of high-purity Fe-Cr alloys have been investigated as functions of composition (0 to 10 wt pct Cr) and rate of quenching from the high-temperature Y phase field (up to 40,000°C sec-1). The structures were chmacterized by transmission electron microscopy. The transformation temperatures for each alloy exhibited the progressive decrease to a constant value with increasing cooling rate which has been shown to be characteristic of several iron binary systems. The corresponding structures were found to become increasingly finer in scale with increasing cooling rate and solute content, but to remain essentially equiaxed in character. In all the materials except the high-purity iron and one of the alloys, an additional and lower transformation temperature than the constant value for the equiaxed structures was observed. The structures of specimens which transformed at these lower temperatures (only single thermal wrests were observed in any given run) were martensitic and consisted of arrays of fine ferrite laths which varied in size and morphology with changing solute content. The factors controlling the nature of these transformations are discussed. The composition dependence of the martensitic transformation temperature, ME, in Fe-Cr alloys together with those reported for other iron binary systems indicate that MB for pure iron is some 700°c, rather than the values of 550° and 760°C reported previously. This conclusion is further supported by the results of a compmison of the thermodynamics of mmtensite formation in several systems. ThE extensive investigations of the structures formed on athermal transformation in iron and its alloys have led to the characterization of several forms of martensitic or "military"1,2 transformations and, in addition, a "civilian7' transformation to ferrite or "equiaxed a"* which occurs athermally and at a very high rate.374

Jan 1, 1969

By Jorge A. S. Tenorio, Chuanwei Zhuo, Joner O. Alves, Yiannis A. Levendis

"The disposal of wastes is a serious environmental problem, since available landfill space is dwindling. Their treatment by pyrolysis or combustion has merit, and the corresponding fuel or power production is of technological interest. However, such processes need a rigid control of emissions. This work addresses the gaseous light hydrocarbons (LHCs) generated during sequential pyrolysis and partial oxidation of unserviceable tires, PET bottles, com wastes (DDGS) and sugarcane bagasse in a two-stage laminar-flow horizontal furnace, kept at 1000 °C. Gas chromatography was used to identify and quantify the components of the emitted gaseous light hydrocarbons. The results showed that the biomass residues generated the highest emissions of aliphatic hydrocarbons, whereas PET generated the most aromatic hydrocarbons. When stainless steel meshes were inserted in the exhaust flow, it was found that hydrocarbon emissions were curtailed; as such meshes catalyzed partial conversion of these carbon-bearing gases to carbonaceous nanomaterials.IntroductionLight hydrocarbons (LHCs) are volatile organic compounds, consisting of hydrogen and carbon with low molecular weight; the most common species are methane, ethane, propane, butane, etc. LHCs are valuable since they are a very important energy resource. However, uncontrolled release of light hydrocarbon gases to the atmosphere should be avoided [l, 2]. In this work, a development is presented for the evaluation of LHCs generated during the controlled pyrolysis/combustion of several wastes in a two-stage laminar-flow horizontal furnace. Samples of unserviceable tires, post-consumer PET bottles and waste residues from the bioethanol industry (DDGS and sugarcane bagasse) were burned. A catalyst system, consisting of stainless steel screens, was tested for its effects on the gaseous emissions."

Jan 1, 2011

By M. Hochenhofer

Due to economic aspects and environmental regulations recycling of slag and waste from ferroalloy production became a very important issue for the companies during the last years. The treatment of slag depends prior on the composition, especially on their content of valuable metals and impurities. The final aim should be a total re-use of these materials in the industry e.g. cement industry, pig-iron production etc.. Therefore, to reach the required physical and chemical properties for a further use, possibilities of a metallurgical treatment have been investigated. The conditioning of slag with a high V-, Mo- and P-content via reducing metal bath showed to be one alternative. To determine the optimal process parameters, practical investigations with different slag compositions and thermodynamic calculations were carried out.

Jan 1, 2006

By Servant S

In the mine of this study, cemented hydraulic backfill is placed under the form of a slurry at a percentage of solid by weight varying from 50 to 65 per cent. This slurry settles and cures in the stope. During this process an important amount of water must be drained from the scope. Field observations in the case studied here show that the geometry of the drains system has a significant impact on the drainage of the stopes. The mode of filling produces a backfill showing an evident stratification typical of a sedimentation process. In situ observations on this material show that this stratification translates into a very strong heterogeneity in the physical properties of the cemented backfill. This heterogeneity should affect the hydraulic conductivity of the backfill in the scope. In order to study this aspect, finite element simulations were performed. This paper presents the results of these simulations, where the impact of this stratification on hydraulic conductivity is related to the performance of the backfill drainage system for various geometry. This preliminary study is aimed at providing a better understanding of the role of the drains in the dewatering process of the backfilled stope in the case of this Mine.

Jan 1, 1998

By Enrique Roy Dionisio Calderon

O presente trabalho mostra a concepção de um modelo que permite gerar uma superfície de mínimo consumo de redutor (carbono) em Altos-Fornos. No seu desenvolvimento foram consideradas as condições de equilíbrio das reações de redução, os balanços de massa e de energia e parâmetros operacionais. Sua aplicação à redução em Altos Fornos é exemplificada para situações reais, baseada em banco de dados operacionais de uma usina siderúrgica. Foi possível, a partir de planos de corte nestas superfícies, gerar diagramas binários do tipo CR-RD (Consumo de Redutor-Fração de Redução Direta), com possibilidade de serem gerados “on-line” no processo. Dentre os resultados obtidos, destaca-se a identificação de inviabilidades termodinâmicas importantes do forno. Dentre elas o modelo permitiu, através de seus “outputs” gráficos, prever e acompanhar o fenômeno de “gelada de forno”, conferindo desta forma maior segurança operacional ao processo.

Aug 17, 2017

By He De-wen

The influence of wastewater containing benzene from chemical industry by technology combined blow-off with Fenton reagent oxidation was experimentally studied. The present results suggest that the technology combined blow-off with Fenton reagent oxidation can effectively remove benzene pollutant in wastewater. The main factors that influence the removal benzene such as temperature and blowing time and volume, pH and reagent dosage of H2O2 and Fe2+ are studied and the optimal experimental conditions are as follows: time 20min, temperature 40i, air-blowing volume 0.4L/min, pH value 5, and H2O2 and Fe2+ dosage 2mL/L and 200mg/L respectively. Under the above conditions, benzene pollutant can be removed up to 97%. Compared to other removal ways of wastewater containing benzene, the technology combined blow-off with Fenton reagent oxidation is more effective and has the advantage of high speed.

Jan 1, 2009

Argentina follows Venezuela and Mexico as the largest producers of crude petroleum and natural gas in Latin America. Argentina 1S practically self-sufficient in fuels, but relies substantially on imports for its supply of copper, iron ore, ferroalloys, sulfur, and fertilizers. Mining activity is limited and is in an incipient stage of growth, considering the country's potential for mining. Most nonfuel mineral output in 1979 consisted primarily of minerals used for construction, while only 9% are other nonmetallic, and 2% are metallic minerals. Argentina is Latin America's major producer of boron minerals and uranium (yellow cake). Mineral exports consist primarily of borates, uranium concentrates, and of late, some tin. These exports have in the past been shipped mostly to Great Britain. London banks have been involved in arranging financing for St. Joe Minerals Corp. IS planned development of the El Pachon copper deposit (see map), and were being counted upon to also back the development of large copper and manganese projects. The following is a review of Argentine mineral production in 1979: (For 1981, the production of boron minerals is put at 167,000 metric tons and uranium at 300,000 metric tons.)

Jan 1, 1982

By G P. Bates

The rationale for the design of the Emergency Egress (escape andentrapment) strategy for one underground metal mine has beenpreviously described (Brake, 1999). Two of the key conclusionsfor this mine, which is equipped with 30 minute oxygen-generating self-contained self-rescuers (SCSR), were the need to ensure no person is ever more than 750 m from an emergency refuge station (ERS) and that it could take up to eight hours to rescue workers from undergroundå. These conclusions were based on a number of considerations including the non-availability of a credible, æpersonalÆ entrapment procedure at the workplace, the duration of self-contained self-rescuers when used for travel, the need for rapid æclearingÆ of mine personnel to effectively and safely target mine search and rescue resources and the maximum time to either put a fire out, or to rescue affected personnel. As there is no Australian standard for refuge stationsç (or for self-rescuers), this paper follows with guidelines for the location and specification of both fixed (permanent) and relocatable Emergency Refuge Stations (ERSs) that may be applicable to other underground Australian metal mines.

Jan 1, 1999

By R. V. Holmes

The properties of the Colorado Copper Co. in Sinbad Valley, Mesa and Montrose Counties, Colo., were rehabilitated and sampled by the Bureau of Mines in October, November, and December 1942. The several deposits were reexamined in March and April 1945 to obtain information disclosed by company work after December 1942. The development program included surface trenching, rehabilitation of several edits, and channel sampling of the exposures. Assay determinations wore made on 204 samples from the surface and underground workings. The results are given in the appendix. Several copper deposits in the Sinbad Valley area are similar in origin. The host rocks are sedimentary and mice in age from Pennsylvanian to Cretaceous. The Colorado No. 3 deposit occurs in the Cutler formation, which consists of many small lenses of conglomerate, sandstone, and shale. Mineralization is closely associated with faulting. On the Pyramid group the enrichment occurs in a zone of fracturing and jointing end also spreads into the adjoining sandstone. The ore deposition on the Copper Rivet claim is associated with a fault zone and is confined to en area above the contact of the Dolores-Wingate formations. Mineral deposits on the Sinbad claims occur at intersections of faults with blue-gray Pennsylvania limestone. Copper enrichment occurs along faults and as replacement of the surrounding limestone. Metallurgical tests indicate that ores from the Colorado No. 3 and Pyramid claims can be treated successfully by leaching with sulfuric acid. This method cannot be applied to ores from the Copper Rivet or Sinbad deposits because of high calcite content. Flotation tests at Boulder City, Nev., showed a recovery of less than 60 percent with a 14.24 percent copper concentrate.

Jan 1, 1952

The following is an incomplete list of members and guests who called at Institute headquarters during the period July 10, 1919, to Aug. 10, 1919. Howard C. Arnold, Washington, Pa. J. S. Lane, New York City, N. Y. L. M. Banks, Denver, Colo. H. W. Lawrie, Washington, D. C. George S. Blair, Pittsburgh, Pa. J. L. McAllen, Latouche, Alaska. Richard H. Catlett, Newark, N. J. David F. McFarland, Urbana, Ill. George L. Clark, Council Bluffs, Iowa. James F. Magee, Lancaster, Pa. Capt. Frederick S. Cook, Portland, Ore. A. G. McGregor, Warren, Ariz. John J. Croston, Atlanta, Ga. Emory M. Marshall, Santa Fe, N. M. Thomas Davis, Seattle, Wash. Benjamin L. Miller, Bethlehem, Pa. J. C. Dick, Salt Lake Cite, Utah. 2d Lieut. C. 0. Noble, U. S. Army. Chris. G. Dobson, Vancouver, B. C. Irving Perrine, Hutchinson, Kans. H. S. Emlaw, Grand Rapids, Mich. Fred S. Porter, Seattle, Washington. F. A. Fahrenwald, Cleveland, Ohio. Capt. H. R. Robbins, Peking, China Lieut. James L. Head, St. Louis, Mo. Joseph P. Ruth, Jr., Denver, Colo. A. A. Holland, Napanu, Canada. William A. Simkins, San Francisco, Calif. W. E. Hopper, Washington, D. C. T .V. Smirnoff, Siberia. Harry Hotchkin, Chicago, Ill. Harrison Souder, Cornwall, Pa. L. L. Hutchison, Tulsa., Okla. F. J. Sur, Denver, Colo. Paul S. King, Wilmington, Del. Harry Wolf, Denver, Colo. George K. Anderson, Jr., lies accepted a position as manager for Wight & Co., producers of air-cooled blast-furnace slag, at Longdale, Va. J. M. Armstrong, with the Caribbean Petroleum Co., has been transferred from Philadelphia to Maracaibo, Venezuela. Fred Sherman Baker, who has been with the Oriental Consolidated Mining Co., at Unsankinko, Chosen, Korea, is now at Columbia City, Ind. Ray J. Barber has removed from Roxbury, Mass., to New York City, and is now consulting engineer for the Roxbury Cold Mines, Inc.

Jan 9, 1919

By J. S. Y. Wang, R. C. Trautz

A 9-meter-long drift was constructed in the unsaturated-fractured tuff at Yucca Mountain to evaluate the potential for water seeping into an underground opening. Forty seepage tests were performed by releasing a finite volume of water at a constant rate into short test intervals located in boreholes positioned above the drift. The seepage threshold flux, defined as the liquid-release flux at and below which water will not drip into the opening, was determined for 10 test intervals. The seepage data, observations, and model results indicate that a seepage threshold exists because a capillary barrier diverts water around the opening.

Jan 1, 2000

By Wilbert J. Huff

For the past 9 years , the technical studies conducted by the Explosives Division of this Bureau have been summarized in a series of reports issued annually . The following account presents investigations undertaken from July 1 , 1943 , to June 30 , 1944. The work is detailed under a number of main headings corresponding to the organizational structure of the Division , the various activities being under the immediate direction of unit chiefs , who report directly to the author . Specific credit , however , is due to the individual unit leader and his assistants .

Jan 1, 1945

By A. B. Hooker, L. C. IlsLey

In lare-scal e blasting, it is customary to fire me.l'\Y shot.!:l simu1. taneously. The electric !atonators ara usually conneced in seies, ard are fired either from a power circuit or :from a blasting ma.chine with large capacity, operated by hand. "!hen :'::ri111; with a blasting ca.chine, trouble with missed shots has been freqi.,.ently e>:pert0nced.. Unit1:i:' thes ,:::rcu:ns tances, the shots that fail to fire are often a gr"up in the t.:E"nter r,f t>e series, Various explaz,.a.tions hs.ve been given as to the cause of the failurs. Tis paper covers a few tests made cy the electrical section of tl:.e Dti..'t'cau. cf Mines, wh;.r.;h may be helpful in understanding the -probable cuse of tl1e misfiring of c.:anter shots, Wh3tever th9 source ot the firir. current generator, magneto, or batter, the CUl"rent delivered th:·01.1.gh a shot-f:?·ing circu.it is determined by t.ae total resistance of ,;he clrcili +.; c:1nd all cure:it leaving th9 p,si tive terminal must return to tre negative te1-minal. If a. metallic circuit is well i1,.sul.:tted, praeti­ccl. l;1 a.ll of the t.'Urrent keepo within the circu.it; but in a. shot-!11·.irig ci.rc1li t, Nhere the ·.vires f:ll·e often 1n c.c,i.cact with the eru:"!ih as i11 wet holer., end whero the ins".lla.tion of the leg wires :i. inadecpa.te to prc·,ent lea.l.tage, the current ma.v tu.e v a.r ious pa the: thro-.. .. gh the nr r. earth.

Aug 1, 1922

By Thomas A. Morgan

The distribution of stress adjacent to each of 25 mine openings was determined by the borehole stress-relief method in the FMC Corp. Westvaco trona mine at Westvaco, Wyo. The purpose of the stress determinations was twofold: First, to study the effect on these distributions of various factors such as opening shape, stress level, and loading history; and second, to estimate the distribution of stresses adjacent to extensive high-extraction (85 to 100 percent) areas. Stress distributions in areas of low average stress correspond closely to the theoretical distributions based on elastic theory. However, in areas of high average stress, the stress distributions are of a type associated with plastic failure. The stresses adjacent to a mined-out area supported by remnant pillars were significantly higher than the stresses adjacent to another area in which the remnant pillars were removed.

Jan 1, 1965

By S. Klingmann, G. Blackwell

"Terrestrial photogrammetry has been used for many years to build three-dimensional pictures for analytical purposes. Photographs can include images from open pit mine walls, ground topography, mine buildings infrastructure or accident scenes. Analysis and co-ordinate estimation in early photogrammetric systems demanded the use of specialized and costly optical-mechanical stereocomparators. Few of these instruments could be interfaced with computers to provide databases, and all required trained personnel with good perspective vision to collect data.Digital photogrammetric software has replaced these older systems, and the digital video plotter (DVP) is a simple computerized system utilizing readily available PCs to quickly produce a stereoscopic model of any scene where an area of overlap exists in photographs taken from two different locations. Specialized cameras providing reference marks or grids on the photographs are still necessary for detailed analysis in three dimensions.This paper describes the application of DVP to the three-dimensional analysis of strike, dip and location of dominant fracture planes visible on an open pit wall slope, and the intersection of planar features which might reduce wall stability. Where reference survey points cannot be provided because access by personnel to the photographic scene is impossible for safety reasons, normal case terrestrial photogrammetry can provide the necessary control points for more complex aerial photogrammetry geometries.DVP recreates the geometry existing at the moment photographs are taken, providing the user with the ability to safely recreate, compare and analyze the structures determining the stability of open pit wall slopes."

Jan 1, 2003

By Fred N. Kissell

Air recirculation caused by dust scrubbers at coal mine working faces was examined by the Federal Bureau of Mines with regard to the potential hazards caused by a possible buildup of methane gas. A theoretical analysis indicated that there was no apriori way to predict the effect of scrubber recirculation on methane concentration levels. Experiments conducted in a full-scale model of a working face area indicated that methane levels were dependent to a great extent on the location of the scrubber exhaust, but that the scrubber recirculation did not substantially increase the methane concentration above those levels that would have prevailed were the scrubber not in operation. An analysis of two underground scrubber trials showed that the scrubbers had no significant effect on methane levels, and a review of explosions attributed to recirculation showed that these were characterized by a lack of fresh air as well as recirculation. It was concluded that high methane levels are due more to a lack of fresh air than to recirculation.

Jan 1, 1975

By Sidney Katell

This Bureau of Mines study estimates typical capital investments, operating costs, and selling prices for two bituminous coal strip mines in the Eastern and Interior provinces and a subbituminous coal operation in the Northern Great Plains province. The annual productions were based on tonnage required to fuel a 250-MM-scfd, high-Btu gas plant. The annual tonnage for the Eastern province mine is 4.8 million tons; for the Interior province mine, 6.72 mi 11 ion tons; and for the Northern Great Plains province mine, 9.2 million tons. It is assumed that the mines have a 20-year life. Wages and union welfare payments are considered as of May 12, 1974, under the terms of the Bituminous Wage Agreement of 1971, and costs for material and equipment are based on 1973 and early 1974 indexes . Initial capital investment varies: $45,358,600 for the 4.8-million- ton-per-year (MM tpy) mine in the Eastern province, $54,603,000 for the 6.72 MM tpy mine in the Interior province, and $29,871,000 for the 9.2 MM tpy mine in the Northern Great Plains province. Total capital invest-ments for the Eastern province mine, the Interior province mine, and the Northern Great Plains province mine are $61,070,000, $76,753,000, and $56,286,000, respectively. Corresponding selling prices for the coal, per ton, are $4.79, $4.23, and $2.66, assuming a 12-percent discounted cash flow rate of return after Federal income taxes. These studies are considered typical for the areas involved. Costs will vary depending on specific locations in these areas.

Jan 1, 1974

By Avery H. Reed

RECORD production of portland cement, crushed limestone, marble, lime, and clays highlighted the mineral industry of Alabama in 1959. Among the States, Alabama ranked second in production of bauxite, and third in output of iron ore, scrap mica, and native asphalt. Alabama's mineral industry was dominated by the mining and processing of coal and iron ore, which accounted for 51 percent of the total value of production in 1958 and 1959. Other important industries were cement manufacturing, petroleum, and stone quarrying. Leading companies were Tennessee Coal & Iron Division of United States Steel Corp. (coal;. iron ore, limestone, lime, and magnesium compounds), Southern Cement Co. Division of American-Marietta Co. (cement, lime, limestone, and miscellaneous clay) , Woodward Iron Co. (coal and iron ore), Alabama Power Co. (coal), and Ideal Cement Co. (cement lime, and miscellaneous clay) .

Jan 1, 1960

By A. J. Vivyurka

"This is a talk about the experiences that Rio Algom Mines Ltd. has had in the Elliot Lake uranium area trying to make the tailings more compatible with the surrounding environment. To get a better idea of the problem that we are associated with we have to go back to the location. The Elliot Lake uranium area is situated about half way between Sault Ste Marie and Sudbury and is about 20 miles north of Lake Huron. In 1950, uranium was discovered along the north shore of Lake Huron and by 1961 we had up to 9 mines operating in the area. Then the United States Atomic Energy Connnission withdrew their contracts so that at present there are only 2 mines operating. From all the mines that we had operating, we ended up with 7 tailings areas. From these 7 tailings areas we have 5 sites where we have active treatment or rehabilitation. There is the Pronto site where we are treating uranium tailings and copper tailings. There is the Lacnor-Nordic site which is located just out of Ellio Lake. The Milliken-Stanleigh site is in the Crotch Lake area. The Panel tailings is off the north end of Quirke Lake and finally there is the operating property of Rio Algom Mines at Quirke Lake.To understand fully the problem with this rehabilitation we have to look at the constituents of the ore. The ore body is a quartz conglomerate with uraninite and brannerite as the uranium bearing minerals in a fine ground mass of quartz, sericite and pyrite which separates the larger quartz pebbles. The approximate composition of the ore is: 80% quartz, 13% chlorite, 7% pyrite and 0.2% uranium minerals. The processing method also adds a few constituents to the final tailings."

Jan 1, 1975