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Traditional mineral processing techniques are more and more difficult to recover the increasingly low grade phosphate ores today. Although bioleaching method has been attempted to process low grade ores in hydrometallurgical field due to economical and environmental reason, it has been hardly used in leaching phosphate ore at home and abroad. Strains of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans were collected and separated from the acid drainage of a coal mine in Anhui province of China. Ultraviolet irradiation and Microwave inducement were applied to the bacterial cultivation process to produce strains of Acidithiobacillus thiooxidans and Acidithi-obacillus ferrooxidans able to tolerate extremely low pH conditions and generate sulphuric acid by oxidizing elemental sulfur or sulphide and the mutagenesis can achieve higher leaching rate. The bioleaching result will improve more by the addition of Tween series surfactants.

Jan 1, 2014

By Eleanor Abshire

This bibliography is the second in a series that covers the current technical literature relating to the metallurgy of zirconium. The rapid advance in zirconium technology makes it mandatory that abstracts be prepared and compiled as soon as possible to have maximum value; therefore, the information in this volume is not arranged chronologically. As a service to research and production groups, succeeding bibliographies will be issued as new acquisitions accumulate in the Zirconium Information Center sponsored by the Department of the Navy, Bureau of Ships and the Bureau of Mines at the Bureau's Northwest Electrodevelopment Laboratory, Albany, Oreg. The initial volume, Information Circular 7771, Bibliography of Zirconium, covering 969 abstracted reports and 645 United States and foreign patents, was published in April 1957.

Jan 1, 1958

By S. K. Kawatra

Many mineral oxide and multi-component oxide (basalt) specimens break down into powders upon expo-sure to sodium vapor at elevated temperatures for extended times. This paper examines several possible mechanisms of oxide breakage by sodium vapor, both experimentally and from a thermodynamic viewpoint. The oxides for which reduction by sodium was thermo-dynamically favorable all exhibited some degree of fragmentation. The oxides which were not favorable for reduction by sodium did not exhibit fragmentation, with the exception of rutile, a titanium oxide. The rutile fragmentation was caused by the reduction of iron that was in solid solution in the rutile crystal structure.

Jan 1, 1995

By Wesley T. Holmes

In this final stage of a three-part investigation of the smelting of titania-bearing iron materials, the Bureau of Mines conducted semicontinuous smelting tests in a laboratory electric arc furnace on four concentrates and one are. The objective was to substantiate the significance of liquidus temperature measurements in predicting satisfactory slag compositions in electric furnace smelting of titaniferous magnetites to produce pig iron. Previously obtained liquidus temperature data were used in determining flux requirements. Self-fluxing pellets of either ore or concentrate plus fluxes and reductants were made to produce pig iron and slags containing 0.2 to 0.6 percent titanium. Individual constituents of the slags generally agreed within 5 percent with the value of the corresponding constituent of target composition. Liquidus temperature of furnace slags generally agreed within 50° C of the value obtained from corresponding nominal synthetic slag. The results of the three phases of the investigation may serve as guide-lines for determining flux requirements in smelting a wide variety of titaniferous magnetites and other titania and iron-bearing materials.

Jan 1, 1969

By Gary P. Sames

This report discusses some practical applications of a geotechnical investigation conducted by the U.S. Bureau of Mines that can help mine operators meet revised Federal regulations in their roof control plans. The investigation, designed to characterize roof conditions near the coalbed outcrop in drift coal mines in eastern Kentucky, revealed that weathered stress-relief joints near outcrop are crucial ground control factors in the region. The joints' origin and character were determined through underground mapping of many joints in coal mine roof and detailed observations and measurement of joint trends and physical characteristics in widely separated strip mine highwalls and roadcuts. This resulted in an understanding of stress-relief-joint patterns and the effect of various rock types on the intensity of weathering in the joints. That information is used in this report to show how stress-relief joints contribute to roof failure and how, through improved roof support and mine planning, safer roof support plans can be developed.

Jan 1, 1992

By E. Swartzman

"IntroductionGENERALLY, the necessity for mining coals of higher impurity content, the drive for lower costs by intensive mine mechanization, changing market requirements, and the increasing competition of oil and natural gas, have continued to result in an upward rise in coal preparation, and have necessitated a more intensive study of coal preparation problems.Increasing adoption of •continuous mining equipment, for example, is introducing new problems in coal preparation. Limited experimental work in the United States (1) shows that the effect of the continuous miner on size distribution varies with the characteristics of the seam. In some seams, the fines problem is lessened, in others it is greatly aggravated. Generally there is a decrease in the relative amount of the top sizes (plus 2 in.) and a substantial increase in the intermediate sizes (down to about 1/8 in.). Contrary to expected results•, where continuous miners with vertical-moving cutting heads are used, an increase in impurities in the slack sizes does not necessarily occur where draw-slate is taken. This is because the draw-slate tends to be kicked out in lump form. However, if a seam contains bands •and lenses of impurities they are bound to be in the mined product."

Jan 1, 1952

By Prashant Dixit, Akhil Singh, Asim Kumar Mukherjee, Sudipta Patra, Veerendra Singh

Phosphorous is an undesired element present in iron ore used in the steel making process. It leads to an increase in overall production cost as well as deteriorated steel quality. The desired phosphorus content in iron ores used in steel making is < 0.1%. Numerous beneficiation studies are mentioned in the literature; however, there is no commercial scale technology established to beneficiate high phosphorous iron. The major phosphorous bearing minerals are apatite (Ca5(PO4)(Cl/F/OH), wavellite (Al3(PO4)2(OH)3·5(H2O)), senegalite (Al2(PO4)(OH)3(H2O), barrandite ((Fe,Al)PO4·2H2O), etc. Ultrafine grinding is required to liberate phosphorous minerals from iron ore minerals and subsequently subject it to flotation, acid leaching, and bioprocessing. The selective flotation of iron ore could successfully reduce the phosphorous content from 0.82% to < 0.20% with the combination of grinding, magnetic separation, and carbothermic reduction. Acid leaching processes are also able to remove ~80% (0.85%→0.16%) of phosphorus; however, these are relatively costly and complex processes. The mechanism of bio-extraction for phosphorous removal is reported as one of the most successful processes. This process is capable of removing more than 80% of the total phosphorous and significantly reducing the phosphorous content from 1.06% to 0.16%. The main disadvantage of this process is that it occurs at a much slower pace. In today’s scenario, ultrafine grinding followed by froth flotation seems to be the most feasible solution for the beneficiation of high phosphorous iron ore in which the concentrate obtained can be utilized for pellet making and ultimately used for steel making processes. Development of additives for leaching, roasting, and bioprocessing can be explored further to make these processes more effective and economically viable.

May 28, 2024

The evaluation of Abandoned Mined Lands can involve the investigation of very large areas of land. Often, the locations of critical areas or impending problems are unknown, and are not easily identified from the surface. Microseismic monitoring has been demonstrated to be effective in identifying potential instabilities and active movement in mines from distances of several kilometers. By placing sensors in proximity to, or in contact with, a high acoustic conductance layer close to the mined zone, large areas can be monitored for potential problems with a minimum of sensors and drillholes. As part of a U.S. Bureau of Mines contract, a prototype system was developed to identify and locate potential instability problems over wide areas of land. Once a problem area has been located, the system can be used to analyze the type of the problem, its size, relative degree of instability, and potential for damage. Continued monitoring after application of remedial measures can effectively determine the efficacy of those measures.

Jan 1, 1993

By Elham Najafi, Sina Ghassa, Ata Akcil, Hadi Abdollahi, Sandeep Panda, Zohreh Boroumand

The present study investigates the influence of ferrous iron (as FeSO4) and ferric iron (as Fe2 (SO4)3), and pyrite (FeS2) on the ability of bacterial leaching of a high-grade sulfide Zn–Pb ore. In this regard, shake flask experiments were carried out at 5% (w/v) pulp density of the ore sample (having 40.7% Zn and 12.4% Pb initial metal content) using a consortium of mesophilic iron and sulfur-oxidizing acidophiles. A concentration of 0.04 mol/L of ferric iron in the leaching media was found to be optimum for zinc extraction without affecting growth of the microorganisms. Under this concentration, the dissolution of Zn, Pb, Cd, and As was found to be 57%, 0.2%, 0.03%, and 9.9% in 25 days. Using ferrous iron in the media, 0.16 mol/L of Fe2+ was found to be the optimum concentration for efficient bacterial growth and metal dissolution (54.6% Zn, 0.08% Pb, 0.03% Cd, and 10.2% As) from the sample in 25 days. On the other hand, using pyrite as the source of energy for bacterial growth, an initial 12-day lag period was observed when compared to the effect of ferrous iron in the media. Under the optimum concentration (test with 0.24 mol/L iron in the form of pyrite), the dissolution of Zn, Pb, Cd, and As was found to be 39.8%, 0.1%, 0.03%, and 10% in 25 days. The surface chemistry analysis indicated formation of a sulfur layer over the particle surface that hindered reagent diffusion and affected metal recovery through bioleaching.

By Francis X. Murray

Synthetic fuels will be the first major development effort to feel the effects of a new set of opposition forces. These confrontations will not be of the same variety as those which occured in the 1970s. Instead the synfuels industry, particularly in the West, will find itself confronting a new coalition of local political, community, and state spokesmen. They will oppose synfuels because the projects will represent a threat to existing lifestyles, political structures, taxes, social life, water rights, economics, and other politically sensitive considerations. In short, they mean change -- usually dynamic, full of unknowns and always threatening. The battles themselves may be fought technically over environmental issues, law and regulations; often these will be the instruments of the opposition. The real underlying problems will likely lie much deeper. In many cases environmental groups will be enlisted as the standard bearers; however, this approach may simply reflect the fact that environmental objections are convenient or at times the only tools at hand.

Jan 1, 1981

By Richard L. Fowler

Study and development of sensing techniques and sensors were performed to aid shuttle car drivers in detecting obstacles and in guiding the car along the face haulage route. Microwave, acoustic, and optical sensing techniques were considered as part of the feasibility study for obstacle detection. Various guidance techniques, including wire-following and rib-ranging were investigated. Active optical sensing was selected for obstacle detection to obtain the beam coverage and sharp angular cutoff characteristics required within the packaging limitations defined by the shuttle car configuration. Rib-ranging guidance was selected to achieve a completely self-contained shuttle car system which responds to the existing mine geometry without need for wires, stripes, or other path defining devices. Extensive hybrid computer simulation runs were performed to evaluate various guidance techniques during the feasibility study. Subsequent simulation runs were performed to establish parameter values for the rib-ranging guidance system. The obstacle detection and guidance system was designed, fabricated and installed on a standard shuttle car. The system satisfied all applicable permissibility requirements of Schedule 2G. An experimental permit was issued to Bendix for operation in an underground coal mine. System evaluation tests were performed first above ground at the Bendix Research Laboratories. The simulation model was validated by these runs. Final testing was performed underground in an operating mine with an experienced shuttle car driver. All sensors successfully demonstrated the predicted performance capability during underground face haulage tests. Dust did not impair system performance and lens cleaning was not required during working shifts. Further development is required to achieve the desired obstacle detection performance. Closed loop steering control with manual override is recommended for the lateral guidance system. The guidance system should be an invaluable aid to low-coal shuttle car drivers where continuous mining machines are utilized.

Jan 1, 1973

By Alan J. Solomon

The function of advertising is communication. Viewing the advertisements of mineral suppliers exposes the reader to a broad spectrum of purposes: announcements of new products, availability and supply, departmental services, company image, etc. It is the advertiser&apos;s hope that the message being conveyed is the same message being perceived by the viewer. To maximize this probability, the advertiser at least must carefully construct precise copy, identify the target audience and select the appropriate advertising medium. A truly successful and efficient ad, however, also must accurately reflect a product&apos;s life cycle, i.e., the rise and fall in demand for a product. Buggy whips and radio tubes are classic examples of items formerly in high demand. Industrial minerals are similarly affected by occurrences of product life cycles.

Jan 1, 1983

By G. W. Josephson

JUDGING by the progressive atmosphere prevailing in the nonmetallic mineral industries during the past year, postwar conditions were healthful though inflationary. Demand for most industrial mineral products has been exceptionally high and many new production records were attained. Severe shortages of some commodities existed, especially building materials and fertilizers. Production costs and prices increased and profitable operation was general. Under these conditions expansion programs were the order of the day. Ample funds were available to finance the purchase of good equipment; and, as wages and other operating costs were increasing, primary emphasis was placed on attaining maximum efficiency in new installations. These efforts were hampered by shortages and slow delivery of desirable equipment, so compromises in design were often necessary. However, on the whole, production practice improved.

Jan 1, 1948

By Lloyd A. Morley

This final report concludes the documentation under Grant G0155003 and details research not covered under foregoing report volumes. The first chapter lists all other reports. The following chapters are divided into three major research tasks: Continuous Safety Monitoring Systems, Battery and Battery-charging Safety, and Mine Power System Transients. The monitoring chapter discusses the prediction of power-system failures. The battery chapter details work on battery-box stresses, battery chargers, and the elimination of electrocutions. The final chapter covers transient instrumentation, distribution transients sources and suppression, and utilization transients on mine power systems.

Jan 1, 1981

By A. E. Stewart

Slope design in an open pit mine includes determining bench height, bench face angle and berm width. Case histories are presented of two highwall slopes (160 and 220 m or 525 and 720 ft high) excavated in dipping strata in an op¬erating coal mine. These examples illustrate the influence that bench face angle can have on the stability of an entire slope. The two highwall slopes, the lower of which experienced significant instability, were excavated in approximately the same lithologic and structural environment. The main differences between the slopes were the angle at which the bench faces were excavated and the excavating methods that were used. Relevent aspects are also described of the engineering geology, slope design and excavation procedures.

Jan 1, 1998

By Stephen Hardcastle

Personnel Heat Exposure Issues In Canada?s Deep Mechanized Mines ?Project developed in 2004 ?Base/precious metal industry identified heat stress/management as a major challenge affecting productivity and operating costs ?Project started in 2005 ?Current research nearing completion ?Guidelines, further data analysis and ?Communicating the Science? will continue into 2011 Managing Heat Exposure Control?. The cost implications ?Controlling the environment ?Ventilation already a major expenses/energy user ?Large Canadian mines are currently delivering massive volumes of air 15-20 tons of air/ton ore ?Large investments in ventilation upgrades, mechanical cooling

May 1, 2010

By E Widzyk-Capehart, P Vallejos, R Asenjo, J Ruiz-del-Solar

Throughout the minerals industry, it is evident that a new wave of technological innovation is needed as the mining sector looks for ways to achieve higher security and safety as well as higher production rates with less investment. Innovation has always been one of the key factors in achieving success within the mining industry. However, its importance will be especially relevant in the coming years if negative trends in commodity prices and new challenges facing the industry (lower grades, deeper mines and economy of scales) are to be overcome and the future sustainability and profitability of the sector ensured.The drive towards fully autonomous operations has begun, with the implementation of automated systems in both surface and underground operations. However, these automated systems are currently planned and realised with well-defined automated tasks within structured environments and isolated spaces. Currently, there is no interaction between automated systems, manned systems or humans, which creates physically isolated environments.For fully autonomous and continuous operations, the automated systems need to operate in environments that enable flexible interactions between automated machines, tele- and manually operated machines and humans.In this paper, we address the automation paradigm considering the synergistic collaboration between humans and automated systems. In this paradigm, humans and machines would interact in a flexible, collaborative and synergistic way without the need for isolation. The implementation of this concept within mining operations will have to be underpinned by science and technological developments and will require adaptation from many fields, including robotics, automation, distributed systems, communication, human factors, pattern recognition and mine design.The paper also presents the research and development work being undertaken at the University of Chile’s Advanced Mining Technology Center, in collaboration with the Chilean mining industry. This will provide the basis for flexible interactions between humans and technology-based systems towards a future of autonomous and continuous mining systems.CITATION:Ruiz-del-Solar, J, Widzyk-Capehart, E, Vallejos, P and Asenjo, R, 2015. Synergistic collaboration of humans and automated systems – innovative steps towards fully autonomous and continuous mining systems, in Proceedings Third International Future Mining Conference, pp 83–94 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By D. Malhotra

The effect of some of the reagents, namely hydrocarbon oil, Syntex (sulfated coconut oil surfactant), pine oil, sodium silicate, and lime, used at the Climax mill on the recovery and grade of molybdenite and gangue minerals has been investigated experimentally using factorially designed test approach in the laboratory. The results of the investigation are presented in two dimensional plots. The lower additions of lime (equivalent to a pH of 8 to 8.5) were desirable for maximizing recovery subject to constraints on grade. Higher additions of pine oil improved recovery, but only at the expense of grade. A mathematical model of the objectives of an operating plant was formulated and optimum reagent conditions obtained.

Jan 1, 1977

By William M. Knuth

The objectives of this study were the evaluation of the technical and economical feasibility of utilizing color and color infrared aerial photography to satisfy some informational needs for pre-mine planning, mine progress monitoring, and reclamation monitoring. Seven aerial data collection missions were conducted within a two year period over strip mine sites in Pennsylvania. Scales of 1:6,000; 1:12,000; 1:24,000; and 1:48,000 were flown on the first aerial mission. The 1:12,000 was chosen as the optimal scale for the remaining six flights. An extensive literature and legislative review and discussions with strip mine operators identified the informational parameters that could possibly be obtained from aerial photography. Interpretability accuracies were evaluated for parameters in the broad categories of land use, soils, water, vegetation, and geology. Seasonal interpretation characteristics were noted for infrared photography. Man hours for photointerpretation and costs of aerial data collection were monitored closely and incorporated into a cost benefit analysis. Those parameters that could be mapped, identified, or measured with accuracies =75 percent were incorporated into a photointerpretation training manual. An additional analysis was performed to determine the applicability of the interpretation methodologies and results developed for Eastern sites to Western surface coal mining sites. In addition, a separate aerial photographic interpretation manual was produced during this contract. It is intended to be utilized by eastern and midwestern surface mine operators and regulatory personnel.

Jan 1, 1978

By Norman A. Parlee

Introduction The principal primary iron and steel producing capacity of the Dominion Steel and Coal Corporation is at the Dominion Iron and Steel, Limited, plant at Sydney, Cape Breton Island, Nova Scotia. The main raw materials are Cape Breton coal, Wabana (Newfoundland) iron ore, and Port-au-Port (Newfoundland) limestone. This plant, which was established at the turn of the century has gradually expanded its production facilities so that today its ingot producing capacity is over 720,000 tons annually. Principal operating units of the plant at present are three batteries of 173 Koppers by-product coke ovens with conventional by-product recovery equipment, three blast furnaces .of 15 ft. 6 in., 18 ft. 3 in., and 19 ft. 3 in. hearth diameter (inside the brick), one 700-ton hot metal mixer, ten open hearth furnaces (two of 175-ton capacity, three 12 5-ton, five 60-ton), one 10-ton electric furnace, a 40-inch blooming mill, a billet mill, a rail mill, a tie plate mill, rod and bar mills, and a wire and nail mill. Extensive machine shops and an iron and brass foundry are also available for plant maintenance and repairs. This paper will describe developments during the past five years and those now in process. It will also briefly discuss research being done and indicate the direction of future development.

Jan 1, 1951