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By A. C. Johnson

This report describes exploration, development, and exploitation methods, and summarizes costs at the Stormy Day mine, which was discovered in 1941. Several shipments of tungsten ore were made in 1944 to the Metals Reserve Company, Salt Lake City, Utah. The purchase of tungsten by the Federal Government, which began in 1951, stimulated interest in tungsten, and a successful program of exploration with participation of the Defense Minerals Exploration Administration (DMEA) indicated enough ore to warrant development of the property. Development work comprised drifting, crosscutting, and raising. Shrinkage stoping was used for mining the ore. Operations were suspended in October 1956, when the Federal Government terminated its purchase program. Total production of the mine was approximately 20,000 tons of tungsten ore. INTRODUCTION This information circular is one of a series, prepared in cooperation with various mining companies and published by the Bureau of Mines, relating to methods and costs of equipping and developing mining properties in the United States.

Jan 1, 1958

By A. H. Shapiro

A decanter centrifuge of novel design was developed for the dewatering of fine-solids slurries having micron-range particles that form paste-like, flowable, hard-to-dewater cakes. The design combines a compound beach with a cake-flow control structure that allows expressed liquid from the cake in the dry beach region to be returned back to the liquid pool while maintaining high solids throughput. In order to provide optimal performance with various operating parameters (feed rate, centrifugal gravity, pool, differential speed, concentration of feed solids, and different slurry types), the cake-flow control is adjustable. The second part of the beach is preferably at zero angle. Tests showed that the new design allows increases in both solids dryness and solids throughput.

Jan 1, 2001

By William P. Shinn

Jan 1, 1881

By A. G. Pasamehmetoglu, N. Bolukbasi, O. Koncagul

A study has been undertaken to establish the relationships between the O&K wedge test cutting resistances and the geotechnical parameters of rock materials in the context of bucket-wheel excavator operation. Prediction equations were formed to estimate the cutting resistance from the geotechnical parameters by multiple regression analysis. The cone indentor index, uniaxial compressive strength and Shore hardness parameters have been found to be the most significant predictors

Sep 1, 1991

By Mostafa Benzaazoua

Les remblais en pâte cimentés sont de plus en plus utilisés dans les exploitations minières souterraines. Une autre alternative d?utilisation du remblai en pâte consiste à le pomper et à le stocker dans des empilements de surface. En plus d?avoir des avantages d?un point de vue de stabilité physique des ouvrages, le remblai en pâte cimenté en surface permettrait également de stabiliser les contaminants dans la matrice du remblai à l?aide du processus de solidification et de stabilisation. Dans cette étude, des remblais en pâte constitués d?un résidu minier sulfuré renfermant beaucoup d?arsenic et de différents liants ont été testés afin d?évaluer la stabilisation des contaminants dans la matrice de remblai. La méthode utilisée pour évaluer la stabilisation et la solidification des contaminants est le test de lixiviation en extracteur de Soxhlet. Les résultats géochimiques issus de ces essais ainsi que la caractérisation chimico-minéralogique des remblais lixiviés ont été analysés pour comprendre les phénomènes chimiques présents dans les remblais durant le temps de cure. Les résultats obtenus montrent que les sulfures présents dans les remblais étudiés (pyrite FeS2 et arsénopyrite FeAsS) s?oxydent et provoquent la dissolution des hydrates les plus vulnérables (dissolution de la portlandite Ca(OH)2 et/ou décalcification des gels CSH). Le calcium produit permet de précipiter les sulfates (essentiellement sous forme de gypse plus ou moins hydraté) et l?arsenic sous forme d?arséniates de calcium plus stables. Les différents liants utilisés donnent des résultats différents en termes de stabilisation et de solidification qui seront discutés dans cet article.

Nov 1, 2002

By G. V. R. Landman

In the early days of underground coal mining, the use of explosives to break coal resulted in a large number of disastrous methane and coal dust explosions and consequential loss of life. Research by the British, French, US authorities, amongst others, introduced many practices that significantly reduced the occurrence of such incidences. The use of explosives designed to be safe in a methane atmosphere, plus the creation of a second free face were two such practices which became commonly used in coal mines all over the world including southern Africa. With its associated coal cutting equipment and labour, the cost of creating a second free face is significant and this, together with the constant drive to reduce mining costs in a competitive market, causes mine management to regularly question the need for the second free face. Also, the safety and nature of permitted explosives has changed considerably since the days of black powder and nitroglycerine-based explosives with the introduction of water-based explosives. In southern Africa mining regulations pertaining to the blasting of coal has its origins in British research which was largely done in the first half of the twentieth century. More recent research by the US Bureau of Mine has resulted in a deeper understanding of some of the mechanisms of methane ignition by explosives and suggests that some of the earlier regulations can be relaxed to a certain extent without compromising safety. This paper gives an overview of the original research done in Europe and the more recent work in the USA, to give mine management and regulatory authorities a deeper understanding of the important safety issues when using explosives in a methane atmosphere. It also suggests that blasting off the solid is no less safe than using a second free face providing certain safety procedures are followed.

Jan 1, 2000

By Wilton Johnson

Native asphalt was produced in 1982 by five companies in two States, Texas and Utah. Bituminous limestone, used primarily as a paving material for street and road repair, was produced by White Uvalde Mines and by Azrock Industries, Inc., Uvalde County, Tex. Historically, gilsonite, a solidified hydrocarbon found only in Utah and Colorado, had been mined by American Gilsonite Co. and by Ziegler Chemical and Mineral Corp. from properties near Bonanza, Uintah County, Utah. During 1982, Hydrocarbon Mining Co., a subsidiary of the Oberon Oil Co., entered into a joint venture with Miocene Resources Inc. of Novato, Calif, to form Hydrocarbon Resources Co. for the purpose of mining gilsonite about 50 miles south of Vernal, Uintah County, Utah. Under the agreement, Hydrocarbon Mining contributed gilsonite-bearing properties held by lease or sublease as well as mining equipment to the venture. The property contained leases totaling 760 acres with probable reserves of 268,000 tons of gilsonite. Miocene Resources provided the partnership with a minimum of $200,000 to develop two of the leases and were to be responsible for management of the mining operations.2

Jan 1, 1983

The objective of this study was two-fold: 1. To perform a world literature search pertinent to the analysis, selection and design of hoisting systems and their components and to codify the search into a literature compendium. The search resulted in a technical data file of over 1500 hard copy items. The compendium index was also suitable for establishing a comprehensive computer-loaded data base on the subject. 2. To develop a comprehensive system of guidelines to cover salient aspects of analysis, selection and design of electrical, mechanical and structural components of a hoisting system with a view to establish parameters for maximum safety and efficiency of operation, installation and revision of the system. 3. Considerations in the mine shaft layout, design, sinking, outfitting, testing and commissioning are set forth against the background of requirements of applicable parts of Code of Federal Regulations, Title 30.

Jan 1, 1988

By S. O. Bada

Fine phosphate feed is considered to be slime and normally disposed of as a discard in settling ponds or dumped as landfill. The purpose of this research was to establish whether commercially acceptable qualities and yields could be obtained from this material using dry separation methods. The results obtained from the electrostatic separation of <105 µm phosphate ore are presented. An existing separator was upgraded in order to improve on product and flotation concentrate recovery, to test different mineral, and to reduce particle residence time between the charging chamber and the separating zone of the separator. The operating conditions were varied according to the charges imparted to the particles in the electric field, and according to other device parameters. Parameters such as splitter position, charge reversal, rotation speed, charging voltage and separating voltage. The <105 µm phosphate feed was concentrated under both triboelectrification and inductive charging. The use of inductive charging and charge reversal resulted in a significant increase in grade for <105 µm phosphate feed, with the P205 grade increasing from about 12 per cent to 20.50 per cent, and a recovery of 26.30 per cent under a single stage of separation. It was found that better separation was achieved at rotation speed of 6000 r/min, -8 kV charging voltage, and 25 kV separating voltage.

Jan 1, 2012

By McHenry Mosier

The Bureau of Mines, United States Department of the Interior, has established a testing adit on the Government reservation at Mount Weather, Virginia, to facility to research on the fundamental tats of mining under actual metal-mining conditions. A number of sites in several Eastern States were investigated, out Mount Weather was selected because the rock seemed best suited for rock drilling and other mining tests and because the ground was already owned by the Federal Government, the site having been acquired in 1902 for use of the Weather Bureau. The testing edit has an advantage over en active metal mine for certain investigations because variable conditions affecting any particular research problem can be controlled and maintained in a fixed status, whereas in an operating mine this seldom is feasible. Operations were begin September 1935, with a crew of four laborers under a resident engineer. The laborers were recruited from, nearby farms, and. although they had no previous mining experience, they have developed into satisfactory miners.

Jan 1, 1939

By J. C. Kerkering, S. M. Miller, P. C. McWilliams

Researchers at the U.S. Bureau of Mines investigated the use of close-range photogrammetry and subsequent stereo digitizing to obtain data from rock fracture roughness profiles. The photogrammetric process yielded results that were acceptable but somewhat inferior to those obtained by a mechanical profilometer. On the basis of this study, further pursuit of photogrammetry as a data collection method in mining is proposed. Fractal geometry was investigated as a means of measuring the roughness of rock fracture profiles. Four fractal algorithms were used: divider method, modified divider method, box method, and spectral method. A comparison of the methods gave ambiguous results. Brown&apos;s modified divider method provided the best means of obtaining the fractal dimension. Shear strength estimates were obtained using the parameters of the modified divider method and Myers&apos; Z, measure. Because of differences in results when comparing the different ways of obtaining the fractal dimension, future users of fractals in studies of rock fractures are advised to cross-check their results carefully.

Jan 1, 1993

By José Antonio Enríquez

El presente texto describe las características estructurales y estratigráficas de los yacimientos epitermales de baja sulfuración en el corredor estructural de San Pablo en Porculla, Cajamarca. En este sentido, el corredor se relaciona a un sistema de fallas regional que tiene rumbo general NW-SW y está segmentado por fallas transformantes de dirección NE-SW, que limitan bloques estructurales. Asimismo, sobre este corredor estructural se ubican en forma alineada una serie de yacimientos epitermales del tipo baja sulfuración. Los yacimientos están controlados por fallas de dirección NW-SE y contienen mineralización en vetas y mantos con relleno de cuarzos, calcita y baritina con importantes valores de oro y oro-plata y las estructuras menores relacionadas a las fallas transformantes. Finalmente, estos yacimientos pueden constituir un nuevo e importante objetivo de exploración por minerales de oro – plata del tipo bonanza.

Sep 12, 2005

By G Fergus, M Hart, S W. Weeks

Rio Tinto Alcan has undertaken feasibility level assessments into the expansion of its bauxite mining operation in an area south of the Embley River in far north Queensland. The project has the potential to extend their Weipa operations by approximately 40 years.The construction and operation of two additional mineral ore processing plants are proposed for the South of Embley project. Golder Associates was engaged to develop and conduct modelling assessments of potential sources of water supply required by mineral ore processing.Two models were developed using GoldSim: a dam yield model and a water balance model. GoldSim is a graphical object-oriented modelling environment with a capacity to carry out dynamic probabilistic simulations. Originally developed by Golder, GoldSim has been applied successfully in a decision support role to a range of mine water management operations.The dam yield model was used to provide estimates of reliability and volume of annual water supply of several potential surface water dams. This information was then used to determine a hierarchy of water supply options for processing plant operations. The water balance model dynamically simulated the water demands of the two production plants and the consequential response in water supply, with respect to the timing and discharges provided by the various source options.Use of the model provided a preliminary operational tool to assist with water supply management decisions. Water quality issues required a blending of water from separate sources and attention paid to scheduling to ensure water supply through the dry season. The model also helped identify risks to water supply in the event of underperformance of one or more water supply sources. This allowed the operational rules to be refined to minimise those risks.The dynamic and stochastic modelling approach provided a method for identification of water supply issues susceptible to seasonal climate variability.CITATION:Weeks, S W, Hart, M and Fergus, G, 2013. A dynamic evaluation of water supply security susceptible to climate seasonality, in Proceedings Water in Mining 2013, pp 197-208 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By N. C. Matheson

The West&apos;s Shell Pile has been used on sites with very soft ground conditions for over 60 years. Fibre reinforced precast concrete shells 900mm long are threadled onto an internal mandrel which can be extended according to the depth driven to attain the load bearing resistance. On completion of driving the mandrel is removed leaving the precast shells to form a permanent lining to the cast insitu concrete core. To give resistance to high contamination, a tar based epoxy coat is sprayed on the outside of the shells or a flexible PVC liner is installed inside the shells to protect the core. Fundamental to the resistance to contamination is the quality of the precast fibre reinforced concrete shell, the mix design and method of manufacture. A series of detailed laboratory experiments were carried out using samples immersed in concentrated acid and sulphate solution. The long term effects of exposure to contamination is recorded in the case studies of existing piles at two gasworks sites.

Jan 1, 1989

By Andrew P. Jarosz

The present computerized mine planning systems use CAD-like and Data Base Management System (DBMS) environments for the handling of numerical, textural, and graphical data. These two environments are usually integrated, that the data provided by the DBMS are linked to any graphical element rendered by the CAD system. The subsidence monitoring, analysis and prediction process should be integrated with the mine design process. It should allow for the assessment of impacts of mining on surface, surface utilities, and structures. It should also provide for the measures to control mining, that will create only acceptable levels of negative impacts on the surface. The common data base, and graphical capabilities of the CAD interface, may be used with great advantage for both systems. The findings of the subsidence engineering modulus should be directly incorporated into the mine design system, and vice versa. In this paper the author suggests guidelines for the development of the comprehensive computer system, able not only to predict the vertical and horizontal components of the ground movement, but also assess the induced surface damages, and costs related to subsidence prevention and compensation.

Jan 1, 1995

By Marcelo Cervantes Del Rio Baptista

Nos últimos anos a indústria siderúrgica no Brasil vem sofrendo um processo lento e cruel de encolhimento de sua participação no PIB, em decorrência de diversos fatores políticos e econômicos. Apesar do grande esforço por parte das empresas, a capacidade de produção de aço pouco cresceu neste período, permitindo que as despesas cresçam mais rápido do que as receitas. Esses fatores têm mostrado aos profissionais do setor que a mudança do cenário só ocorrerá ao se produzir com o máximo de eficiência. O objetivo deste trabalho é demonstrar que a lubrificação tem grande participação no aumento da produtividade e redução de custos da manutenção. Em suma, será apresentado um estudo sobre como a lubrificação correta influencia no aumento da produtividade das siderúrgicas. Com base nos resultados dos testes realizados em duas grandes empresas do setor, este trabalho demonstra o aumento significativo de performance no Mandril da bobinadeira e mancais dos convertedores, após estudo detalhado da lubrificação.

Aug 17, 2017

By J. B. Gilliatt

The discovery of ore at Wabana was quickly followed by the mining of the ore beds where they outcropped in the land areas. The third phase, as at present carried out, consists of extensive submarine operations, which were commenced in 1908, by driving a pair of slopes out under Conception bay, opening. the mine for a distance of a mile and a half from the shore. Two other slopes, now driven just beyond the shore line, are being sunk to the submarine territory where, it is generally recognized, huge reserves of ore lie under the bay. The process of erosion of the land, the solution and re-disposition of its iron-bearing minerals in thick beds of ore have been considered elsewhere, but these bear small relation to the physical forces which have acted upon the ore-beds since the deposition of the strata. These physical changes are made manifest by jointing and cleavage and faulting. The discussion of these, the relation they bear to each other, and to the folding of the strata, is the purpose of this article. For the benefit of those who may not be familiar with the formation in which the ore occurs, I include a general summary of the geology of Be!! island and its environs; also a description of conditions that prevailed during the period of deposition, so that the reader may appreciate some of the later changes that took place during or subsequent to its emergence from the sea, and the folding or tilting of the strata to the position it now occupies.

Jan 1, 1924

By J. C. Edwards, C. C. Hwang

In ventilated tunnel fires, smoke and hot combustion products may form a layer near the ceiling and flow in the direction opposite to the ventilation stream. The existence of this reverse stratified flow has an important bearing on fire fighting and evacuation of underground mine roadways, tunnels and building corridors. In the present study, conducted by the National Institute for Occupational Safety and Health, a CFD program (fire dynamics simulator) based on large eddy simulations (LES) is used to model floor-level fires in a ventilated tunnel. Specifically, the critical ventilation velocity that is just sufficient to prevent the formation of a reverse stratified layer is simulated for two tunnels of different size. The computer code is verified by checking the computed velocity profile against experimental measurements. The CFD results show the leveling-off of the critical ventilation velocity as the heat release rate surpasses a certain value. At this critical ventilation, the ceiling temperature above the fire reaches a maximum for both tunnels. The velocity leveling-off can be explained from this observation. An extended correlation of Newman (Combust. Flame 57 (1984) 33) is applied to the temperature profiles obtained by CFD. At the critical ventilation, temperature stratification exists downstream from the fire. The computed critical ventilation velocity shows fair agreement with available experimental data taken from both horizontal and inclined fire tunnels. The CFD simulations indicate that the Froude modeling is an approximation for tunnel fires. The Froude-scaling law does not apply to two geometrically similar fire tunnels. The CFD results are compared with two simple theories of critical ventilation by Kennedy et al. (ASHRAE Trans. Res. 102(2) (1996) 40) and Kunsch

By John Ellenberger

The nature of a stone deposit is rarely defined through exploration and engineering design, but more through the actual experience encountered as the mine develops; hence, issues with ground control are often at the forefront for a new mine. Ground control problems account for over 15 percent of lost-time injuries in underground stone mines. The objective of this work is to present actions taken during early development of a stone mine to mitigate the obvious effects of high horizontal stress on ground control. The mine was developed from a box cut with relatively little cover, and high horizontal stresses were not anticipated. Early recognition of possible high horizontal stress resulted in mapping of the mine using the NIOSH-developed Roof Fall Risk Index (RFRI) to provide a baseline to objectively analyze roof conditions. A program of borescoping the mine roof provided valuable roof beam thickness data and found that the roof beam was of minimal thickness, approximately 10 percent of drift width. As the mine developed, it became apparent that ground control problems related to high horizontal stress existed. A concentrated effort was made to improve ground conditions by implemeting a number of mitigation techniques. Actions taken by the mine included systematic roof support, reorientation of mining direction, a lower roof horizon, reduced span widths and reduced mining height in crosscuts to prevent running falls. These strategies resulted in signifcantly improved ground stability.

Jan 1, 2012

By J. P. Rider

Operating practices and resulting production from longwall faces are continually improving. Consequently, longwall operators are continually seeking to improve the dust control capabilities on longwalls. The National Institute for Occupational Safety and Health (NIOSH) has been conducting dust surveys at longwalls throughout the country in an effort to document the types of controls that are being used and to quantify the relative effectiveness of these controls. To date, surveys have been completed at longwalls in Alabama, Colorado, Pennsylvania, Utah, and West Virginia. In addition NIOSH has been reviewing longwall dust parameters provided by mine operators to MSHA to assess the status of dust control technology being used throughout the industry. Results from the underground dust surveys and information obtained from MSHA will be summarized in this paper to provide an update on longwall dust control technology and practices.