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By R. J. Wahrer

In 1996, the Office of Surface Mining (OSM) and the U.S. Fish and Wildlife Service (FWS) completed an Endangered Species Act (ESA) programmatic Section 7 consultation. From the resultant Biological Opinion, it was found that coal mining operations conducted under federally approved state regulatory programs would not likely jeopardize the continuation of federally listed species nor result in the destruction or adverse modification of critical habitats. The requirements of the ESA and their integration into the SMCRA permitting process and the responsibilities of the regulatory agency, the FWS and the coal operator will be discussed. Guidance on the development of protection and enhancement plans will be provided and site-specific examples given.

Jan 1, 2003

By Henry P. Cole

A comprehensive review of published research was carried out to identify methods for teaching and assessing critical but nonroutine skills needed for coping with emergency situations. Specific methods for assessing critical skills proficiency in aviation, medicine, organization management, the military, and other industrial/technical workplaces are described. The potential application of these methods for teaching and assessing (1) critical first aid and (2) self-rescue and escape skills to underground coal miners in annual refresher training is explored. Research and development activities that may improve mine health and safety training are suggested. Most of these research and development activities were completed later in the project. This additional work is reported in the project technical report #2 and the final report. The research reported in the present document was completed in 1984 -85. Many of the initial findings reported in this document are updated in the later project final report.

Jan 1, 1988

By Joseline Pérez, Geraldine Pinedo, Sara Blaz

La exploración minera y los descubrimientos son el futuro de la continuidad de Perú como país minero. Conscientes de la importancia de esta actividad, el presente ensayo se enfoca en identificar problemas críticos que, en la actualidad, afectan a los proyectos de exploración minera, principalmente a nivel de cronograma, y que restan competitividad a nuestro país. Este trabajo visibiliza cómo los titulares mineros pueden llegar a tener cronogramas de hasta de 2 a más años para poder iniciar exploración y la importancia de atender a este problema a través de soluciones regulatorias y de gestión en los distintos niveles y de forma transversal con otros sectores.

Sep 29, 2023

By J. P. May

This U.S. Bureau of Mines report identifies and evaluates factors responsible for dump-point accidents involving mobile mining equipment. Information regarding the occurrence and severity of the accidents, the industries affected, the types of equipment involved, the primary and contributing causes, and pertinent Federal regulations is included. The aim of this report is to provide information that will aid mine operators in the recognition of hazards associated with mobile equipment operation near the dump points of stockpiles and waste dumps.

Jan 1, 1990

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions5/ issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1961

By W. J. McKenna

This paper, describing the milling practice at tine lead-zinc concentrator of the International Smelting Co., is one of a series of papers on milling methods being prepared by the United States Bureau of nines. The concentrator is operated as a unit of the International Smelting Co. and is located about 40 miles southwest of Salt Lake City, at Tooele, Utah. The Tooele Valley Railroad, operating between the plant and Warner, Utah, a distance of 6.5 miles, makes connection with both the Union Pacific and Denver & Rio Grande Railroads.

Jan 1, 1933

By J. B. F. Champlin

The continuing development of the nuclear industry in the United States requires a program of waste disposal that insures against the release of large amounts of radioactivity to the environment. This paper describes research on one proposed means of disposal of this waste, that of injection into geologic formations at depth. Nuclear production plant wastes were simulated and injected into samples of sedimentary rock obtained from outcrops, quarries, and deep wells. Changes in the chemical and physical characteristics of the rocks caused by the interaction of ions and suspended particles in the waste solutions with the cementing material and claylike particles in the rock are discussed. Laboratory tests show that nuclear wastes can be injected into many natural porous, permeable geologic formations. Injectivity can be maintained over a longer period by monitoring the ionic balance and particle-size distribution of waste streams. The combination of permeability and porosity with low cation-retention capacity, as exhibited by most sandstones, would satisfy the engineering requirements for the subsurface disposal of nuclear waste. Shales and clays with their low permeability and high cation-retention capacity would make excellent confining formations. The amount of cation retained by sedimentary rocks increases with increasing valence or concentration of the cation or decreasing brine concentration. The use of rock cores as model reservoirs had proved successful in determining some of the parameters that need to be considered in full-scale field disposal of wastes.

Jan 1, 1967

By Hongqiang Wang, Qingliang Wang, Eming Hu, Zhiwu Lei, Fang Hu, Rui Zhang, Wei Hou

Pyrite, a mineral associated with uranium ore, is closely related to uranium leaching. In this study, Ozone micro-nano bubbles (OMNBs), as an environmentally friendly advanced oxidation technology, were used for the first time to oxidize pyrite under experimental conditions to improve the leaching rate of uranium. A laboratory-scale agitation leaching experiment of pyrite was carried out with a pH of 1.0–3.0, gas flow of 1–3 L/min, ozone generation rate of 0.55–2.22 mg/s, and pyrite concentration of 0.1–5.0 g/L for 1 h. By adding three different co-oxidant: Mn(II), Mn(IV), and Fe(III), it was found that only Mn(IV) increased the oxidation rate of pyrite by 21.7%. The results of the scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) show that the formation of Fe(III)-O film on the surface of the ore suppresses the oxidation rate of pyrite to a certain extent. Pyrite can be rapidly oxidized up to 57.6% by OMNBs, which is beneficial to uranium leaching. This method is expected to be used for in situ acid leaching of uranium with OMNBs injected into the ground.

Jan 3, 2022

By M. Oliazadeh

Spodumene [LiAl(Si2O6)] is the most common and desirable economic lithium-bearing mineral due to its high lithium content. In Canada, there are several spodumene deposits at the development stage that have the potential to help narrow the forecast lithium supply gap stemming from the widespread acceptance and increasing use of electric vehicles. Spodumene processing can be conducted using Dense Media Separation (DMS), flotation or combination of both. If spodumene liberation is sufficient at coarse particle sizes, DMS can be used for primary lithium concentrate production and silicate gangue minerals rejection. If liberation is not sufficient, flotation is then the main processing route for spodumene concentration. Even in cases where DMS is a viable beneficiation option, flotation may still be required to process the DMS middlings and/or the undersize fraction which is outside the particle size range for DMS. Considering flotation as a technique for spodumene beneficiation, there are several alternatives including the use of mechanical flotation cells, column flotation cells, coarse particle flotation cells, and/or Staged Flotation Reactors (SFR), either alone or in combination. Ore sorting can be incorporated at the start of the spodumene flowsheet to remove gangue minerals, particularly amphibole and pyroxene in the early stages. The main objective of flowsheet development for hard rock lithium deposits is to evaluate the ability of these options to produce a spodumene concentrate with a concentrate grade above 6% Li2O, lithium recovery of above 80%, and with the minimum operating and capital cost. This paper aims to describe the various processing options available for the beneficiation of spodumene from hard rock deposits and compare the associated operating and capital costs for each.

By Ross L. Sherlock, David J. Scott, Gordon MacKay, Wayne Johnson

"Abstract - The demographics of Nunavut indicate a very young and poorly educated population spread over wide areas in small isolated communities. The current economic sectors will be unable to expand and meet the demands of this emerging workforce. Given the realities of Nunavut, the most promising direction in which the economy may expand is through mineral development. The Nunavut Land Claims Agreement (NLCA) has established the legislative framework for sustainable development in Nunavut through mineral development. The NLCA has transferred ownership for much of Nunavut’s potential mineral resources to beneficiaries of the lands claim. Royalties generated from mining operations on subsurface Inuit-owned lands, and to a lesser extent on Crown land, will flow back to beneficiaries of the lands claim through their administrative company, which may then be invested in the communities. Additional benefits of mineral resource development in Nunavut will be realized through impact and benefit agreements.To realize the benefits from mining operations, Nunavut has to be able to attract and support exploration and development companies through the release of high-quality geoscience data. However, due to Nunavut’s isolation and the expense of conducting geoscience fieldwork, the jurisdiction lags far behind the rest of Canada in terms of quality and quantity of government geoscience. About 70% of the territory is inadequately mapped to attract exploration companies or to make informed land-use decisions. The role of government-funded geoscience in Nunavut is to stimulate exploration and discovery through new framework mapping and focused thematic projects. The timely delivery of high-quality geoscience products will attract exploration companies to Nunavut and further their efforts to discover and develop mineral resources in order that the subsequent benefits of this activity may flow to the beneficiaries of the NLCA as well as all other residents of Nunavut."

Jan 1, 2003

By C Munro, S Emery, M Flynn, K Tan

"AEROPHINE® 3418A Promoter is a well-known and widely used collector and is an industry standard for its excellent selectivity and efficacy in the processing of complex polymetallic sulfide ores, particularly those containing silver. Until now, however, it has not found widespread use in primary nickel flotation.In an effort to increase nickel recovery without compromising selectivity over iron sulfides, Western Areas Forrestania Nickel operation trialled the use of AEROPHINE® 3418A as a secondary collector at low dosage. A series of ON/OFF trials were conducted, with the finding that a very low dose of AEROPHINE® 3418A increased nickel recovery by 0.6 per cent compared to using xanthate alone.This paper provides a brief operational history and overview of the Forrestania operations, a description of the trial and an analysis of the results.Citation:Emery, S, Flynn, M, Tan, K and Munro, C, 2016. Aerophine® 3418A Promoter as a Secondary Collector to Boost Nickel Recovery at Forrestania Nickel Operations, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 145–148 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By H. W. St. Clair

Sampling of heterogeneous mixtures of fused metals or solidified melts is subject to errors not met in sampling finely ground ores or granular materials. These errors arise largely because of the segregation of constituent metals that usually takes place during solidification. It is seldom that a random sample of a lot of metal will represent the composition of the entire lot. The problem becomes especially difficult when it is necessary to make accurate analyses for a segregated impurity present in very small amounts. This paper discusses some of the pertinent experimental observations made in selecting a method for sampling melts of aluminum and zinc containing small amounts of iron and silicon as impurities. Although this experimental study dealt only with sampling this specific combination of metals, many aspects of the study apply generally to any mixture of mol ten metals containing minor constituents that segregate rapidly during freezing of the melt.

Jan 1, 1949

By Palma O. Manuel

El presente texto describe el desarrollo de la actividad aurífera, así como el análisis de las técnicas y los métodos de explotación en los yacimientos detríticos de oro. En ese sentido, se analizan los criterios sobre el proceso de explotación y los resultados de dichas investigaciones realizadas por el Instituto Geológico Minero y Metalúrgico.(INGEMMET). Asimismo refiere los depósitos auríferos, perforación, explotación y concentración gravimétrica, metodología de la explotación y la amalgamación en la mina.

Nov 8, 1982

Note: This is a progress report and therefore not necessarily conclusive. Further data may result in conclusions somewhat different from those reported here. Crop Growing Season The monthly average temperatures, total precipitation, and evaporation for the demonstration mine are shown in Table 1. [ ]

Jan 1, 1980

By T. L. Iapalucci

To determine the behavior of chlorine in coal combustion, the Bureau of Mines burned 10 chlorine-containing coals, high-, medium-, and low-volatile, in a laboratory-scale pulverized-coal combustor. At carbon-combustion efficiencies of 94 to 98 percent, 1.6 to 7.1 percent of the chlorine or an average of 4 percent of the chlorine in the coal was retained in the ash; the balance, predominantly hydrogen chloride, was evolved in the combustion gas. Sulfur retention in the ash ranged from 2.3 to 10.7 percent or an average of 6.3 percent, Addition of alkali and alkaline earth carbonates to a medium-volatile coal containing 0.27 percent chlorine by preferentially reacting with the chlorine increased the Cl/S atom ratio in the ash, Lithium carbonate addition at 0.43 percent and K2C03 at 1.59 percent increased the C1/S ratio in the ash from 0.2 to 0.6.

Jan 1, 1969

By H. W. J. P. Neomagus, R. K. K. Mbaya, J. R. Bunt, N. T. Leokaoke, N. W. Makgobelele

Silicon Smelters consumes more than 80000 t/a of wood-derived charcoal as carbonaceous reductant in the production of silicon metal. More than 10% of this material is discarded as fines (<6 mm) generated due to abrasion during processing. Charcoal fine residues (<650 μm) and polyvinyl alcohol (PVA) binder were used in this study to produce mechanically strong charcoal briquettes for metallurgical application as carbonaceous reductant. The PVA binder was added in mass percentages of 1, 3, and 5 wt% to the charcoal fines. The compressive strength, abrasion resistance index (ARI), drop shatter resistance (SRI), and water resistance index (WRI) were measured as functions of curing for up to 7 days under atmospheric conditions, and the results compared with metallurgical grade coarse charcoal. The ash content of the produced briquettes was found to be high (6.6–8.0%) compared with the coarse charcoal (1–3%). The 3 and 5 wt% PVA-bound briquettes were found to be the strongest, with compressive strengths of 40 and 115 kg/cm2 respectively, with WRI values of 75 and 73% respectively. The produced briquettes were found to have lower ARI and SRI values compared to the coarse charcoal. Future work should include beneficiation of the fine charcoal discards prior to briquetting, and an increase in binder addition to above 6 wt% to improve the ARI and SRIn.

May 1, 2021

By Dunbar D. Scott

The development in the perfection of mine-surveying instruments has been by no means rapid, as it has depended somewhat on the details of construction borrowed from astronomical and geodetic theodolites, largely on the restrictions laid down by mining companies and the prejudices of mine managers themselves, but more than all on the methods used in conducting surveys and the importance attached thereto. Mine-surveying, in some form or other, has been practiced from the very earliest times; but it has never kept pace with the other branches of surveying, or even with the art of mining itself, and cannot be recognized as an exact science until shortly before the beginning of this century. The works of Hero of Alexandria, who lived in the second century B.C., are still extant, and contain descriptions of a rectangular sighting-instrument, which he invented and called a diopter. His improvement upon this simple construction, which possibly he devised for use in the Greek mines for rough leveling-purposes and for laying out any angle, must be considered, says Hübner," as the origin of the highly perfected theodolite of to-day. Whether this instrument came into general use during the first centuries of the Christian era, is not recorded; in fact, no writer undertakes to tell how mine-surveying was conducted until 1556, in which year Agricola expounds the principles of mining and metallurgy in his De Re Metallica, devoting the entire fifth chapter to the practice of mine-surveying (see Fig. 1). In mediæval times those who possessed any knowledge of engineering skill made strenuous effort to keep their art a secret, partly on account of the miners&apos; proverbial conservatism and partly for their own personal aggrandizement, and were, in

Jan 1, 1899

By Antônio César de Araújo Freitas

As empresas de mineração têm desafios logísticos em sua operação no dia a dia, visto o crescente volume de minério movimentado nas Usinas e Portos e pressão crescente por resultados operacionais que se traduzem na busca contínua por níveis superiores de produtividade. A tecnologia de automação dos processos produtivos e de máquinas evoluiu muito na última década, entretanto o processo da logística nos pátios de matéria prima e produtos apresenta baixo nível de automação e é baseado em informações verbais e observações visuais a respeito do nível de estoques e disposição dos materiais nas pilhas e áreas dos pátios de manuseio. Em um processo tão complexo, pequenas decisões da operação no dia a dia, que podem variar de acordo com o operador, supervisor ou turno de operação, podem influenciar a produtividade diretamente, afetando indicadores como horas paradas e deslocamento de máquinas por tonelada expedida, afetando dessa forma custos significativos na operação de uma usina ou porto. Este trabalho tem por objetivo então descrever as técnicas utilizadas para modelar os desafios de logística nos pátios de minério, descrevendo sistemas de otimização utilizados com apresentação de resultados em projetos como o de Carajás, planta da VALE que é atualmente a maior mina de minério de ferro do mundo, abordando a redução de deslocamento de máquinas, diminuição da exposição ao risco de colisão e redução de paradas.

Jul 30, 2018

By Irving Wender

This report describes Bureau of Mines experiments and reviews the work of others on the exposure of coal and coal-derived products to gamma rays and some other types of radiation. Results are presented on tests of three bituminous coals and a lignite that had been pulverized to minus 200-mesh particles and exposed to 1,000 megaroentgens of gamma irradiation from spent-fuel elements of a nuclear reactor. Of about 20 chemical and physical tests in Bureau work, only mass spectrometry of gases evolved during vacuum pyrolysis of the coals to 450° C gave results indicating differences in the irradiated and unirradiated samples. Mass-spectral distribution curves for CO and CO2 evolution showed fewer irregularities (reversals of curvature) for irradiated coals; thus, mass spectrometry appears to be the most sensitive method for determining radio-induced changes in coal. It is concluded that coal is not significantly altered by gamma irradiation owing to the resistivity of its highly condensed ring structure. High-level gamma irradiation, therefore, is unlikely to prove advantageous in coal processing and utilization. Specially treated coals, because of resistivity of coal to radiation damage, may be useful as an absorbent in processing radioactive wastes.

Jan 1, 1968

By W. D. Musgrove, B. W. Gandrud, A. C. Richardson

"INTRODUCTION The Cahaba coal field is the second largest coal—producing area in Alabama. This field underlies parts of Shelby, Jefferson, St. Clair, and Bibb Counties and has an area of about 270 square miles. The Cahaba formations contain a number of coal beds, about 8 of which are mined at present. Although the area contains many folds and faults, samples from various mines and beds indicate that, except for the variation in ash content, the coal from this field is very uniform in character and quality. It is a high-volatile bituminous coal used chiefly for steam-raising purposes and domestic fuel. The coal as mined usually contains too high a percentage of impurities to be marketed without some preparation. The majority of the mines have washing plants in which jigs are the favorite type of equipment, although at some mines tables are used for cleaning the slack sizes. The washing characteristics of the coal from the Cahaba field are very uniform and differ from those of the near-by Warrior field, in that the coarser sizes contain a much lower percentage of bony material than the finer sizes. In general, the bone increases with decrease in size. It breaks into thin flakes, making difficult its elimination in the cleaning process, and gives rise to what is known among the washery operators of the Cahaba field as the ""rash problem.""A previous publication 5 referred to rash from the standpoint of jig operation and suggested some means of handling it with jigs. This report presents the results of table tests on two samples of fine coal from the Thompson and Woodstock beds, respectively, of the Cahaba field to determine the influence of rash on table efficiency.This investigation has been made in connection with the study of coal-washing problems now being conducted by the U.S. Bureau of Mines and the University of Alabama, with the cooperation of the different coal operators of Alabama."

May 1, 1934