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By Elio Ferreira

This report describes the design, and development work performed to reduce the volume and weight of the miners caplamp battery, as well as a headpiece with a swivel mechanism containing a halogen bulb with two filaments. Work was also conducted in the development of a maintenance free battery. The design concept is based on non-sintered Ni-Cd technology, with an energy density of 22 Wh/lb. The cap lamp system developed has been approved by the Mine Safety and Health Administration (MSHA) and can be manufactured for mine use.

Jan 1, 1988

By L. O’Connor, E. Tarshizi

The objective of this work is to provide a detailed review and a list of references in chronological order, comprising 80 recent technical papers, on the use of discrete-event simulation (DES) modeling in mining engineering. In this article, the review papers of published mine simulation projects through 2007 are summarized, and then a comprehensive review of individual articles published from 2008 to 2015 is presented. This survey work also includes analyses of the simulation tools used in the published projects, mining types and applications in order to assess these key features and evaluate the recent state of research in mine DES simulation. In addition, an interactive map visualization for the locations of the simulated projects is made available on a website to benefit current and prospective scholars in the field. The results of this investigation revealed that the most common application of DES in mining had been mining equipment selection and analysis, while ore processing and risk management projects were less frequently reported. The results also showed that modeling surface mines were in the majority, but the trend of publications for underground mine simulations had also increased. According to the results, ARENA was the most popular simulation software package, but several simulation tools that were only used once or twice in the mining projects are also included in this review.

Jan 1, 2018

By L. O’Connor, E. Tarshizi

The objective of this work is to provide a detailed review and a list of references in chronological order, comprising 80 recent technical papers, on the use of discrete-event simulation (DES) modeling in mining engineering. In this article, the review papers of published mine simulation projects through 2007 are summarized, and then a comprehensive review of individual articles published from 2008 to 2015 is presented. This survey work also includes analyses of the simulation tools used in the published projects, mining types and applications in order to assess these key features and evaluate the recent state of research in mine DES simulation. In addition, an interactive map visualization for the locations of the simulated projects is made available on a website to benefit current and prospective scholars in the field. The results of this investigation revealed that the most common application of DES in mining had been mining equipment selection and analysis, while ore processing and risk management projects were less frequently reported. The results also showed that modeling surface mines were in the majority, but the trend of publications for underground mine simulations had also increased. According to the results, ARENA was the most popular simulation software package, but several simulation tools that were only used once or twice in the mining projects are also included in this review.

Jan 1, 2017

By James C. Duchon

The use of extended workdays (regular shift lengths of 10 or 12 h (hour), while still maintaining a 4O-h workweek) in mining operations is attracting growing interest in the United States. There is very little doubt that extended workdays is a very popular alternative among the work force because of the significant increase in days off, including weekends, especially when compared with traditional rotation schedules of working seven straight shifts or having only one weekend off every 4 to 6 weeks. However, there are some serious concerns by management, workers, unions, and various governmental policymakers that working 10-or 12-h days may create an added risk of accidents and health problems. The U.S. Bureau of Mines reviewed the literature studies related to the safety and performance issues of extended workdays. This report presents a summary of those findings. The studies examined in this review are divided into three sections: (1) laboratory, (2) field, and (3) accident and injury analysis. In general, results are inconclusive. Studies have shown both positive and negative effects. It is concluded, therefore, that in industries such as mining where accidents are a serious concern, special measures and evaluation in the use of extended workdays be considered.

Jan 1, 1994

By Iván Calmell del Solar Salas

Desde el año 2014, se ejecutaron pruebas piloto en zonas en condición de cierre progresivo dentro de la Unidad Minera Constancia, propiedad de Hudbay Perú S.A.C. El objetivo de estas pruebas fue lograr cierres sostenibles en base a metodologías no convencionales y al uso de conocimiento ancestral local. Para la revegetación de estas áreas hemos sustituido la práctica común de siembra de pastos exóticos de rápido crecimiento, por el uso de recursos fitogenéticos nativos con el fin de proveer a las áreas intervenidas de una cobertura vegetal idónea con el propósito de que sea la base para la rehabilitación y mejora de la Biodiversidad

Sep 1, 2017

By J. L. Holman

The Bureau of Mines is conducting research to recover strategic and critical metals such as Ni, Co, and Cr from mixed contaminated super-alloy scrap. One approach being studied involves melt refining of superalloy scrap to produce anodes for electrolytic deposition of Ni-Co alloy. This melt refining of superalloy turnings is described based on melt-oxidation and oxidation-carburization experiments, using roasted superalloy grinding sludge to supply the 0 needed to oxidize Cr and other readily oxidized elements to the slag. Controlled melt-carburization subsequent to oxidation improved the metal phase recovery of Ni and Co to well over 90 pct and decreased electrolytic solubility of Cr, Mo, and W by carbide formation. Electrolytic refining experiments were conducted using a controlled-potential mode (preset cathode potential). Data show effects of Fe and Cr impurities, cation concentration, electrolyte pH, S04-Cl electrolyte ratio, temperature, cathode potential, and cation-selective membrane use on current efficiency, current density, and deposit composition. Disposition of Ni, Co, Cr, MO, W, and Fe is compared for melt-oxidized versus oxidized-plus-carburized anodes. Deposits containing >97 pct Ni + Co (major impurity Fe) have been routinely obtained from scrap anodes. Research is continuing to improve deposit quality in sustained deposition and to recover Cr and other metals from refining slags and anode sludges.

Jan 1, 1986

By M. M. Wong

Electrolysis of titanium carbide and a material consisting of titanium, carbon, nitrogen, and oxygen as soluble anodes in Used electrolytes was investigated by the Bureau of Mines for the preparation of crude titanium metal. Tests made in all-chloride electrolytes showed only a low recovery of titanium as well as a substantial volatilization of titanium trichloride (TiC13) when present in the electrolyte. Electrolysis at 750° to 850° C in a mixture containing 85 percent NaC1-15 percent potassium floutitanate (K2TiF6) yielded as high as 91 percent recovery of titanium from titanium carbide and 62 percent recovery of titanium from the titanium-carbon-nitrogen-oxygen material. Problems associated with the preparation of crude metal by fused-salt electrolysis are discussed. The crude metals produced from both anode materials were electrorefined in a sodium chloride-titanium chloride (NaCl-TiC12) electrolyte, and ductile titanium metal was obtained.

Jan 1, 1963

By F. R. Archibald

SINCE the opening of the Beattie mine, in 1933, the concentrate produced by flotation has been considered refractory. As the gold extraction by cyanidation was poor, the concentrate, during the first four and a half years of operation, was shipped to a smelter for further treatment. After the installation of the cyanide plant, in 1934, seventy per cent of the gold in the concentrate was recovered before shipment to the smelter. In 1937, a roasting plant was built so that treatment might be complete at the mine. Much experimental work had been done by a number of investigators prior to the installation of the roasters, but none of them had seriously attempted to identify the causes of, or the elements responsible for, the refractory behaviour of the concentrate. Intensive investigation in this direction commenced in the Beattie lab-oratory in July, 1938, has led not only to the identification of several causes contributory to the refractory behaviour, but also to revisions in procedure and principles with respect to roasting Beattie concentrate in particular and arsenical concentrates in general. The accuracy of the identification of these causes and the soundness of the principles is borne out by interpretation of roasting plant records, by improvements and simplification since applied. to plant operation, and also by laboratory and test-plant results on arsenical concentrate produced by another mine. It is the purpose here to present an account and interpretation of the laboratory investigation, together with a correlation of laboratory and plant results. Incomplete extraction of the gold by cyanidation after roasting is due primarily to the nature of the material roasted, and secondarily to the manner in which it has been roasted. There is a possibility that better extraction may be obtained by improvements in both particulars.

Jan 1, 1939

By Charles Prasky

This report describes and appraises recent progress in the development of a differential sulfatizing process for recovering a ferrograde manganese oxide from low-grade manganiferous ferruginous materials in the Cuyuna range. Individual process steps were carried out successfully using a 20-inch-diameter shaft for continuous countercurrent sulfatization of the manganese, a multiple-compartment rotary drum for leaching the water-soluble manganese sulfate, a submerged-combustion evaporator for the recovery of monohydrate crystals of manganese sulfate, and a shaft furnace for the thermal decomposition of sulfate crystals for production of a ferrograde manganese oxide and a sulfur dioxide gas suitable for sulfatization of fresh are. Of the two general kinds of Cuyuna manganiferous materials--the carbonate slates and the oxidized ores--only the slates were studied at pilot scale.

Jan 1, 1963

By J. G. Kirby

According to the Bureau of Mines annual survey, as of January 1, 1954 there were 337 refineries with a total daily crude-oil throughput capacity of 8,006,897 barrels. The total daily capacity increased 368,236 barrels during the year while the total number of refineries declined 6. The capacity of the average refinery to process crude oil therefore increased during 1953 from 22,270 barrels to 23,759. With the exception of the Texas Inland, all refining districts reported gains in the installed capacity for the year, the largest being the Louisiana Gulf Coast with an increase of 20 percent. A total of 397,500 barrels of additional crude oil capacity was reported as under construction January 1, 1954. Accounting for 129,500 barrels of this total are facilities for 3 new refineries in North Dakota, 2 in Washington and I each in Ohio and Utah. Equipment being installed to replace existing units, totaled 180,750 barrels daily.

Jan 1, 1954

By G. A. Smyres

The Bureau of Mines investigated a HCI-02 leaching procedure to recover Cu, Ni, and Co from a low-grade bulk sulfide flotation concentrate prepared from the Duluth gabbro complex. Since the Duluth gabbro complex is the largest known and unexploited Ni resource in the United States, the development of options for extracting the metal values from the flotation concentrate of this domestic resource is necessary. Conditions were determined for producing a pregnant solution low in Fe to facilitate recovery of the metal values. Leaching experiments were conducted at 15 pct solids, 1000 to 1200 C, 0.2 to 0.3 g HCI per gram concentrate in a 50-gal reactor pressurized to 50 pSig with 02. Base metal extractions from the concentrate were, in percent, 90 to 92 Cu, 99 Ni, 97 to 99 Co, and 0.1 .Fe. Precious metals extractions were erratic and unpredictable; at best their extractions were, in percent, 55 Au, 90 Ag, 40 Pt, and 45 Pd. The reaction time at 1200 C was 0.5 h. The use of compressed air instead of 02 as the oxidant was also investigated. Solvent extraction using LIX 622 was used to remove Cu from the pregnant solution. Cementation on Cu was tested for precious metals recovery, while sulfide precipitation was used to produce a Ni-Co product. A conceptual flowsheet for treating the Duluth gabbro concentrate is proposed.

Jan 1, 1985

By D. Bienstock

In connection with air-pollution studies, the Bureau of Mines is cooperating with the U.S. Public Health Service in investigating the use of solids for removing sulfur dioxide in concentrations of less than 0.5 percent from combustion and waste gases. Removal of sulfur dioxide at flue-gas tempera¬tures would no longer result in the cooling of scrubbed gas, which is inherent to liquid scrubbing processes used exclusively in industry today. Results are reported of extensive investigation, using metallic oxides as absorbents, adsorbents, and oxidation catalysts at 130° and 330° C. (temperatures at which flue gas may be treated in powerplant practice). The most active absorbents tested were the oxides of manganese, cobalt, copper, and alkalized alumina; 23 to 33 grams of sulfur dioxidn were removed by 100 grams of absorbent at 130° C., while scrubbing more than 90 percent of the sulfur dioxide from a simulated flue gas, and 19 to 61 grams of sulfur dioxide were removed at 330° C. A more detailed study is reported on absorption and regeneration, using manganese oxides and alkalized alumina. Adsorption of sulfur dioxide on activated carbons and molecular sieves at elevated temperatures is considerably less efficient than removal by absorption--a maximum of 7 to 8 grams of sulfur dioxide could be removed with 100 grams of adsorbent at 130° C. A potash-promoted vanadium pentoxide is effective in converting sulfur dioxide to trioxide; complete conversion in a simulated flue gas containing 0.35 percent sulfur dioxide was obtained at 365° C. Pilot-plant and cost studies are being made by the Bureau to determine the economic feasibility of removing on an industrial scale the sulfur dioxide present in gases in low concentrations.

Jan 1, 1961

By T. J. Smolik

The Golden Sunlight Mine started full-scale operations in February 1983, with a conventional open-pit mine supplying 4464 tonnes (5000 tons) per day of milling ore. After crushing and grinding, the ore is leached with cyanide solution in large agitation tanks. Soluble gold values are removed from the sand portion of the leached ore with five stages of countercurrent washing cyclones. After thickening of the cyclone-wash overflow slurry, the gold is recovered in activated carbon with a six-stage carbon-in-pulp circuit and a five-stage upflow carbon column circuit. Pressure stripping, carbon reactivation, electro-winning and refining complete the gold recovery process.

Jan 1, 1984

By M. A. Kessick

Current treatment and disposal procedures are compared for clay slimes resulting from the extraction of Alberta oil sands, the extraction of Florida phosphate matrix, the recovery of diamonds from kimberlite deposits in South Africa, the recovery of kaolin from clay deposits in southwest England and the upgrading of bauxite ore. Published research in the area is reviewed, and common trends which are emerging in the disposal of clay slimes are discussed.

Jan 1, 1978

By Robert Hopler

Although electrical instruments were being widely introduced into the study of seismic tremors, attempts to understand and quantify shocks from blasting continued to use rather primitive methods well into the 19th century.

Jan 1, 2007

By J. H. East

"INTRODUCTION .Very little information regarding coal mining in Spain has been published in the American technical press, and few people realize the extent of this industry or the conditions under which coal is mined. The information in this publication was collected in 1945 and consists of personal observations in Spain, statistics, and other data of a, general nature obtained from official sources.Spain produces bituminous coal, lignite and anthracite, but the total tonnage mined is less than the national requirements. Before the war, an appreciable tonnages coal was imported from Great Britain under the Anglo-Spanish treaty, which rebated import duties and effectually prevented competition from any other foreign source. The war stopped the major part of the important of British coal and caused rapid expansion of the domestic sources, but this was not sufficient to supply the industrial demand. Coal that formerly was not acceptable to industry because of quality is now mined and marketed. The Government, allocates the better-grade bituininous coal to the various industries in accordance with the national importance of the work in which they are engaged; for example, the railroads are allotted 100 percent of their requirements, but cement companies can obtain only 25 percent.The Government offered to inducements to increase the production of coal of any class, but the larger part of the increased tonnage obtained was in inferior grades; as a result, the lignite production was taxed, while a bonus was paid for bituminous-coal production in excess of the 1942 tonnage.The anthracite and bituminous-coal areas were severely damaged during the Civil War and many experienced miners migrated to the lignite mines in eastern Spain. This has resulted in an acute shortage, particularly the Province of Oviedo where the most important bituminous-coal deposits are located."

Jan 1, 1947

Comparative tests of four coals used industrially for coke production have been made by three laboratories of the Federal Bureau of Mines, each using its standard equipment and procedures for evaluating coal for coking. Two of the coals were blends used in the western and eastern sections of the United States, the third was a strongly coking coal widely used for producing coke in Alabama, and the fourth was a blend typical of those used for producing foundry coke in the Birmingham district. The coals used and the cokes produced from them covered a wide range of chemical and physical properties. The tests used at all three laboratories for determining the physical properties of the cokes were made according to ASTM (American Society for Testing Materials) methods. The excellent agreement found for the physical properties of the cokes indicated that, for the coals tested, the BM-AGA (Bureau of Mines-American Gas Association) 18-inch circular retort used at Pittsburgh, Pa" the 14-inch slot-type oven used at Denver, Colo., and the 17-inch slot-type oven used at Tuscaloosa, Ala., were substantially equivalent for evaluating coals for production of coke. Thus, added value is given to data obtained previously and independently at these three Bureau laboratories. INTRODUCTION Laboratory equipment to produce coke for evaluation has not been standardized by the industry. The results obtained with anyone design of equipment have been regarded as showing only the relative values of coal to produce coke of the requisite quality. Few systematic studies have been made to correlate results obtained in different types of equipment. Results of one, in which the Bureau of Mines participated, were published recently.2/ This

Jan 1, 1961

By J. W. Miller

Wyoming County had for many years supplied large quantities of coking coals to coke plants throughout the eastern United States and Canada. Up to the present most of the coal has been produced from relatively few beds, but in the future the coal will be produced from beds not previously mined in quantity. This trend is shown in the entire Winding Gulf field, of which Wyoming County is a part. This publication is one of a series of Bureau of mines reports appraising the Nation's coking coal, which y be used to determine the practicability of upgrading marginal deposits to metallurgical standards. This investigation of the preparation characteristics of Wyoming County coals is the third of the series undertaken in West Virginia.

Jan 1, 1955

By J J. Robinson, B N. Noller, D M. Franks, G McIlveen, D R. Mulligan, A T. Soro

Fiji is a developing nation that relies on economic opportunities and recently experienced increased interest in mining and mineral exploration that could potentially benefit the country. In order to understand the lack of, or failure of, past rehabilitation activity, this study applied risk-based approaches to identify the significance of activities or actions applicable to rehabilitation of post-mined land in Fiji. This involved the use of qualitative, semi-quantitative and quantitative risk methodologies, which allow assessment and evaluation of mechanisms of mining administration and practices, as well as rehabilitation methods and approaches that have been applied successfully to post-mined land in other countries with similar environmental and climatic conditions and social and regulatory environments to Fiji. The semi-quantitative risk-based technique followed an earlier approach applied for mine closure by Laurence (2006) and provided a systematic way to assess and evaluate rehabilitation issues that were identified on-site by assessors, who were able to estimate through expert judgement the likelihood and consequences based on conditions, situations observed and circumstances on-site. It demonstrated that experienced professionals could reproducibly score likelihood and consequence of selected items relevant to mine site rehabilitation, despite the wide-ranging issues identified during post mined land rehabilitation. The quantitative risk-based approach was adopted as a method to determine environmental bonds for mining projects using the assessment of consequences and likelihood results from the semi-quantitative approach, then incorporating unit cost of materials or activities for local conditions required to fully rehabilitate each issue at net present value. Application to both an abandoned mine site and a newly opened mine site in Fiji showed that this approach could provide a risk-based estimate for rehabilitation cost and demonstrated potential applicable in the Fijian context.CITATION:Soro, A T, Mulligan, D R, McIlveen, G, Franks, D M, Robinson, J J and Noller, B N, ?2014. Risk-based Rehabilitation Strategies for Post-mined Land in Fiji, in Proceedings Life-of-Mine 2014 , pp 165–180 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

1994 estimates for Porgera are probable and proven reserves of 58 200 000 t of ore grading 5 g/t Au. Gold mineralisation is related to an intrusive complex emplaced at shallow levels in poorly consolidated sedimentary rocks. The complex is located in a zone of fold-and-thrust deformation, whose formation may have been initiated shortly before emplacement and continues locally today. Abundant primary magnetite in the complex gives an intense, 5 km wide aeromagnetic anomaly. The deposit formed during two main stages of mineralisation, the first related to early magmatic-hydrothermal activity and the second representing later epithermal overprinting centred on the Roamane fault. Hydrothermal alteration followed closely on emplacement indicating a close genetic relationship between magmatism and mineralisation. Both stages of hydrothermal activity post-date and overprint early propylitic alteration. Several factors have acted in unison or sequentially to concentrate metals at the deposit, including an extensional or trans-tensional tectonic setting within an arc or collisional environment, the exsolution of a magmatic hydrothermal fluid prior to sulphur saturation in the melt, the development of the hydrothermal system into one favourable for transporting gold, the action of late-stage faulting in focusing epithermal fluid flow, and the role of dissolved gases in promoting fluid phase separation and high-grade ore deposition

Jun 19, 1905