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This Bureau of Mines report is devoted to descriptions of investigations pertaining to underground mine trailing cables, their handling, splicing, and the use of couplers.

Jan 1, 1979

Significance of the body of iron oxide, which in part overlies as its hanging-wall the rich chalcocite ore-body at Mount Oxide, Queensland, has been variously interpreted by engineers and geologists who have inspected the deposit.Among the interpretations offered is the one that the body represents the residual of an original medium to low grade...

Jan 1, 1939

The suitability of char from Yallourn brown coal as a filler for carbon electrodes used in the aluminium smelting industry has been assessed on the basis of the specifications usually laid down by electrode manufacturers for petroleum coke fillers. The purity specifications can be met by a simple acid leaching of the coal before carbonization. The true density of char produced at 1200°C is within 5 per cent of the specification figure, but the bulk density of char obtained from as-mined coal is only half that specified for petroleum coke.Although this can be increased to three-quarters of the specified figure by briquetting the coal before carbonization, further increases would be very difficult to achieve, as the remaining shortfall in density is due to an extensive microporosity developed in the particles of char during carbonization.

Jan 1, 1970

By R. W. Fatzinger

The accident-frequency rate for placer mining in 1942 is reported as 36.923 accidents per million man-hours worked. This figure places placer-mining accident frequency slightly higher than that given for quarrying-35.7-but considerably under the 78.0 for coal mining and 56.5 for metal mining.4 Placer mining is subdivided into four types of activity: Underground, surface, dredging, and hydraulicking. It is the purpose of this paper to present and discuss safety practices in dredging and hydraulic mining; therefore, the following considerations will be limited to these two types of placer mining.

Jan 1, 1948

By Martin Murenbeeld

Outlook: Nine Bullish Arguments 1. Global fiscal and monetary reflation: PIIGS, US, etc. 2. Global imbalances: the dollar must decline 3. Global FX reserves are ?excessive?: diversification 4. Central bank attitudes to gold: now positive 5. Gold is not in a bubble: room to rise 6. Mine supply is flat: ?peak? gold? 7. Investment demand: long-run uptrend 8. Commodity price cycle: many years to run 9. Geopolitical environment: positive

May 1, 2010

By G. Huang, S. Vytla

Computational fluid dynamics (CFD) is a continually developing numerical technique by which complex fluid flow problems can be solved on computers. To be able to transfer CFD expertise to analyze and design a face-ventilation system, a comprehensive validation study of current CFD tools against mining-related benchmark experiments is required. In the last four years, such studies, funded by National In¬stitute for Occupational Safety and Health (NIOSH) under Grant #R01 CCR415822, were conducted in the Department of Mining Engineering at the University of Kentucky. A wide array of ventilation schemes and mining configurations were considered. Recently, an additional study was performed in cooperation with the NIOSH Pittsburgh Research Laboratory. This study was dedicated to the methane behavior in the empty (containing no equipment) face area with a blowing curtain and a 10. 7-m (35-ft) setback. In this paper, the authors present and discuss the computer-simulation data and compare them with data collected during the laboratory studies at the NIOSH lab.

By H. Lowers, P. Hageman, S. Diehl, D. Fey

Understanding relationships between mineralogy, texture, microstructural features, and element distribution and residence in minerals, is critical for accurate modeling of mineral weathering in waste-rock piles. The morphology of minerals and deformation structures, such as veins and faults, are important factors that control: (1) fluid access to the mineral surface to initiate dissolution, (2) the distribution of trace elements, and (3) formation of secondary minerals. We characterized the mineralogy, textures, and chemical properties of waste-rock material at three sites at scales ranging from outcrop to micrometer scale. A comprehensive hand-sample to thin-section scale methodology utilizing light microscopy, scanning electron microscopy, electron microprobe, and laser ablation ICP-MS was used to thoroughly characterize the waste-rock material.

Jan 1, 2007

Records over the past ten years indicate that there is potential for serious multiple accidents due to engulfing associated with rockpasses. Significant attention is not usually given to the design of rockpasses, with the implication that mistakes leading to poor performance of the passes are often repeated. This paper outlines general guidelines for the design, support, operation and rehabilitation of rockpasses based on information obtained from the limited amount of literature on the subject.

Jan 1, 2005

The efficiency of water sprays in suppressing airborne colliery dust depends on many variable factors. A survey of previous work in this field shows that swirl spray nozzles are the best dust suppressors.Investigations carried out in an experimental dust chamber show that, in spite of limitations to the application of water sprays in underground use, promising dust suppression efficiencies in mechanised mining can be obtained with swirl spray nozzles.INTRODUCTIONA dust hazard has always been associated with coal mining, and the recent growth of mechanisation has resulted in a greater production of fine coal and dust, thus increasing the hazard. A better knowledge and appreciation of the medical aspects and dust explosion factors has led to practices reducing the seriousness of the problem. However, the dust hazard still exists and its control is basically an engineering problem.Dust, as with any atmospheric pollution, may be removed from the, mine by ventilation, which is an indirect method of control. Direct methods, in which the dust is prevented from being produced and from becoming airborne, should be employed where possible. Of these direct methods the most significant is the use of water sprays.THE DUST HAZARDAn appreciation of the physical nature of the more important dust hazards is necessary before considering the removal of the hazard. The main hazards associated with colliery dusts are the health hazard and the explosion hazard. "Dust" comprises solid particles of size minus 20 mesh Tyler (833 microns).

Jan 1, 1964

By Louis Schaffer

The objectives of the research were to determine whether a model health and safety program could be defined in terms which would enable its application to mines of all types, and, if such a model program could be defined, to determine through evaluations in two mining companies whether it would achieve measurable improvements. Volume 1 describes the model, how it was applied in the field and how it was evaluated. This, Volume 2, describes the literature and field research that preceded the model definition.

Jan 1, 1983

A study of the swelling behaviour of a single batch of high-grade iron ore pellets during hydrogen reduction in a fixed bed showed that the extent of swelling is governed by the nucleation and growth of crystalline iron protuberances from the wüstite grains. Over the reduction temperature range 650 to 1000°C, it was found that substantial degrees of swelling can occur at temperatures in excess of 850°C, and significant variations in the swelling behaviour of individual pellets from different bed levels are observed under these conditions.The results are discussed in terms of a recent swelling theory and shown to be in general agreement.

Jan 1, 1978

By M. Nete

Qualitative analysis of three mineral samples from northern Mozambique was accomplished by X-ray diffraction (XRD), microscopy, scintillation, and magnetic determination. Chemical characterization was accomplished using ICP-OES and pressed powder XRF after dissolution using microwave-assisted digestion and flux fusion. The samples consisted of a mixture of minerals with tantalite as the major component, with minor amounts of microlite, quartz, mica, accessory garnet, and tourmaline. Incomplete dissolution was obtained using microwave digestion, with maximum recoveries of 90.25 ± 0.06% and 88.90 ± 0.04% for Nb2O5 and Ta2O5 respectively. Complete dissolution using Li2B4O7 resulted in recoveries of 98.5 ±0.2% Nb2O5 and 100.4 ± 0.3% Ta2O5.

Jan 1, 2012

By W. E. Halle, G. J. S. Govett

"The Institute of Applied Geology, Manila, Philippines, is jointly sponsored by the University of the Philippines, the Philippines Bureau of Mines and the United Nations Development Programme (Special Fund). It provides, in its fourth year of operation, an interesting example of international cooperation in mineral development. Objectives include: (1) the training of mining engineers in modern techniques of mineral exploration; (2) assisting government and industry in discovering new ore deposits; and (3) providing the basis for the establishment of an economically oriented graduate school of geology at the University, the first of its kind in the country. Training of engineers requires roughly one full year, which is divided between academic study and actual field practice. Lecture and laboratory instruction include courses at university level designed specifically to up-grade those aspects of the geological sciences that are required by mining engineers now qualifying as mineral exploration engineers-economic geology, applied geochemistry, geo-physical exploration, petrology and structural geology. The field training involves direct participation in actual mineral exploration projects arranged with the co-operation of the Bureau of Mines and private interests engaged in mineral development and production. The system works well in practice, and the Institute staff and trainees were responsible for outlining new evidence of economic mineralization. It is also apparent from the application of the exploration methods available to the project -geological mapping, air photo interpretation, magnetic, electric, electromagnetic, self potential and gravity surveying as well as geochemical prospecting -that, under the humid, tropical, mountainous conditions in which the practical program was conducted, air-supported geochemical prospecting with attendant reconnaissance geological mapping affords the most economical and effective approach to mineral exploration for at least some of the deposits characteristic of the region."

Jan 1, 1968

By Bruce Cavender

Historically, the processing function has been regarded as efficiently managed as long as production costs were kept low, recovery was adequate and sufficient plant capacity was avail-able. In this paradigm, processing is viewed as capable of making only a limited contribution to a company?s competitive advantage. However, the processing function can provide a primary vehicle for building critical competitive capabilities. Processing organizations should be encouraged to become so accomplished they generate new opportunities for other functional groups and thereby influence a company?s overall strategy. This requires a deep shift in processing?s role, in its self-image and in the expectations of it held by managers in other functions. Specific plant improvement techniques ? total productive maintenance (TPM), loss control, etc. ? should be viewed primarily as means for building strategically valuable processing capabilities. Different improvement strategies create different kinds of capabilities and present new strategic options. Broadly speaking, a mineral-producing company seeks competitive advantage through two principal activities: the development of new mineral production and reserves and the optimization of existing operations. These lead to increases in ore reserves, production levels and cash flows that are manifested in increased profitability and, hopefully, increases in the price of the firm?s stock. The profitability of a minerals company is a function of the overall profitability of the industry sector in which the company participates and the firm?s competitive position within that sector relative to those of its competitors. Competitive advantage within the industry comes from two sources: the ability to maintain lower prices than competitors for the same product (cost leadership), or from the sale of products with unique properties that justify higher prices (product differentiation; Porter, 1980). Most mineral companies produce fungible commodities that are sold to anonymous customers, and sustainable cost advantage is the only long-run strategy available to these companies to enhance profitability.

Jan 1, 2008

By R. M. Whyte

The Konkola Deep Mining Project (KDMP) seeks to exploit the deep level potential of the Konkola Deeps orebody, producing high grade copper concentrates for treatment at the Nkana Smelter and Refinery. As an alternative to smelting, Konkola Copper Mines (KCM) has examined a processing route involving pressure leaching of the Konkola concentrates at Nchanga, with the leach liquor being treated by solvent extraction and electrowinning to produce high purity copper cathode. The solvent extraction circuit would be operated to achieve a high ?delta? copper, thereby providing a strong acid raffinate which can be used in the existing Tailings Leach Plant (TLP) to treat Nchanga oxide copper materials. The main focus of the hydrometallurgical option is to capitalize upon the synergy that exists between the treatment of sulphide copper concentrates (acid producing) and oxide copper ores (acid consuming). The paper discusses the key features of a comprehensive piloting campaign carried out at Anglo American Research Laboratories, which involved the co-treatment of Konkola copper concentrates and Chingola refractory ore in a fully integrated pilot plant circuit.

Jan 1, 2001

By Harvey L. Pastan

The purpose of the investigation and analysis described in this report is to assess the data flow requirements that are required for remote supervisory control of a continuous mining system. Since these control concepts as applied to continuous underground mining are still in a formative stage at the present time during the first half of 1975, assumptions had to be made based upon engineering judgment as to what embodiment of mining machinery and control methodology seemed most feasible for achieving such a system. Based upon these assumptions and estimates of the control system's accuracy and response requirements, it was then possible to estimate the communication requirements for the assumed system configuration. 2. Approach The team members responsible for this study visited numerous coal mines to observe room and pillar mining operations in both high and low coal. The objective was to observe the methods of operating a variety of continuous mining machinery and haulage equipment with a view toward defining the problems to be overcome in the application of automation to the coal extraction process. Descriptive information concerning the mining equipment was obtained through contacts with the manufacturers. Conferences with Bureau of Mines personnel, equipment manufacturers and developers, and mine operators were held to explore the current thinking and developments being pursued toward automation and increasing both production and productivity.

Jan 1, 1975

By J. Willan

This paper addresses the problem of designing a destress blasting procedure to reduce the incidence of rockbursting in hard rock mines. A review is made of the developed theory and practice of destress blasting in rockburst-prone ground. Specific reference is made to a recent survey of past and current practice with particular reference to Ontario mining operations. The need is identified for a more scientific basis for destress blast design and monitoring. Reference to developments in blasting technology as well as rock mechanics are then made to support a proposed, integrated design procedure and research strategy.

Jan 1, 1984

By Bruno César Calazans de Andrade

No processo de produção de aço o maior volume de custo está na carga metálica, que é composta pelo gusa líquido produzido nos altos fornos e a sucata metálica oriunda dos descartes de processos produtivos da indústria. Visando atingir o custo ótimo de produção, foi definida uma produção dos altos fornos menor que a média histórica da empresa, e a compra de placas no mercado como complemento para suprir a demanda da laminação. Desta forma a otimização da utilização do gusa líquido se tornou primordial para o aumento da produção de placas, redução do custo de produção da metalurgia e consequentemente redução da necessidade de compras de placas no mercado. Com este novo cenário foi necessário aumentar a utilização de sucata pesada e reduzir o tempo de preparação de caixas para garantir a carga no peso e tempo necessário para atendimento dos conversores. As ações tomadas possibilitaram a redução do gusa na carga metálica de 84% para 82% atingido o resultado proposto redução de custo e aumento de produção de placas.

Aug 17, 2017

By L. K. Weaver

The objective of this study is twofold, The first is to present the composition of the offshore petroleum industry in terms of lease bonuses and the value of hydrocarbons produced from Federal offshore tracts. The second is to present costs of producing petroleum (oil and condensate) in the Gulf of Mexico with a financial analysis of an offshore operation. To prepare a financial analysis of an offshore operation, a model was derived to show the costs necessary to explore, acquire, develop, produce, and abandon a 5,000-acre block and the estimated income from the sale of the hydrocarbons produced. To establish cost and income guidelines for the model, a group of seven oilfields in the Gulf of Mexico ranging from 7 to 75 miles from shore and in water 20 to 130 feet deep was selected for study. A net profit or loss statement was prepared for each field and a discounted cash flow rate of return was calculated. Discounted cash flow rates of return for the seven fields range from 1.1 to 19.5 percent. Under the two specified conditions set up for the model (a 20-year and a 30-year oil depletion model), the rates of return are 17.2 and 13.7 percent, respectively. To January 1, 1959, the top four operators in the Federal offshore areas had paid approximately 40 percent of the amount spent on all lease bonuses and produced about 56 percent of the total hydrocarbons.

Jan 1, 1972

By R. D. Currie

A study of the accident statistics in the coal mining industry convinces one that an organized effort must be put forth to prevent the vast destruction of human life in this industry . The fatality rate in Pennsylvania has not improved in the past several years and during 1928 it was higher than the average for the period 1916 to 1927 , inclusive . Although the accident rate for this State is less than that of the coal mines of the United States as a whole , nevertheless the rate is unduly high ; however , there are many companies which have exceptionally good records as regards both fatal and nonfatal accidents . A study of the methods used by some of these relatively good- record companies to reduce accidents in their mines shows that they exert an organized effort to prevent accidents , and that their safety organizations usually affect every employee in and about the mine from the highest official to the check boy . The chief executive must be actively and personally interested in accident prevention if real safety results are to be obtained ; when he shows this interest it is almost invariably reflected in the officials under him and throughout the organization . Safety organizations vary in form and are readily changed or adapted to the varying conditions found in the bituminous field . The companies whose organizations were studied in preparing this report are all getting good results , and it is their opinion that the safety organizations have been a big factor in obtaining these results . At their request the identity of some of the companies whose organizations were studied has not been divulged in this paper , but this does not affect the value of the information concerning their safety organizations .

Mar 1, 1931