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Table A-1. Number of underground coal mines and samples collected for underground occupations, 1988-92 [ ]

Jan 1, 1997

By Alberto Pacheco

El presente trabajo es un análisis del sistema de organización del sistema de seguridad a través del modelo Reason de causalidad o de "queso suizo", donde se identifica qué aspectos y decisiones se convierten en un factor condicionante para un accidente y también cómo la organización puede aprender de un accidente perfeccionando sus defensas en un ciclo de mejora continua. De forma que este modelo explica que un accidente es la consecuencia final de una superposición de fallas que va desde la última línea de defensa, pasando por el acto inseguro, la condición insegura, la falla de la supervisión, la falla de la asesoría (seguridad) hasta la falla de la organización. Para solucionar dicho problema, se realiza una gestión del error que incluye una serie de medidas preventivas como descubrir, evaluar y eliminar los factores que producen el error dentro de la fuerza laboral y así desarrollar la realidad intrínseca de la organización contra los errores humanos.

Sep 13, 2001

By William A. Beck

"In 1912 bauxite was discovered in the Andersonville district, which lies in the 28th and 29th land districts of Georgia and comprises parts of Sumter, Macon, and Schley Counties. Mining was begun in May 1914 by the Republic Mining & Manufacturing Co. Considerable ore has been produced in this region since that time by individual interests and by the American Cyanamid & Chemical Corp., which acquired the property formerly owned by the Republic Co.The area was examined in the fall of 1941 by representatives of the Bureau of Mines and the Geological Survey, after which a prospecting program was begun by the Bureau. Drilling was started on December 26, 1941, and continued until November 18, 1943. A total of 1,192 holes was drilled in the district, and 3,679 samples were taken and analyzed.Mineral exploration agreements were signed by 146 property owners covering 42,128 acres. Holes were drilled on 121 of these properties, which have a total area of 38,778 acres.Drilling under this project disclosed several new deposits, of which four have been completely delimited. Previous prospecting in this area by mining companies did not find bauxite, as it lies under heavy overburden. Work by the Bureau indicates 14,412,000 long tons of ore containing 30 percent or more alumina. The total tonnage is divided as follows:Georgia State Highway Routes 26 and 4-9 traverse the district. The Central of Georgia Railroad passes through the center of the entire district (see fig. 1).The project was initiated by J. R. Thoenen, supervising engineer, Non-metals Mining Section, Mining Division, Bureau of Mines. It was under his general supervision until July 1942, after which it was under the general supervision of E. J. Lintner and Rowe McCrae, district engineers for Georgia, South Carolina, and Flordia, respectively.John C. Feeley, Jr., was project engineer from December 1941 to April 1942. Other engineers who assisted in the work on the project are R. E. Babcock, T. M. Romslo, Don M. Coulter, and Walter T. Lewiecki.Acknowledgment is due the metallurgical staffs at College Park, Md., and Tuscaloosa, Ala., for analyses of samples and beneficiation tests.Acknowledgment is also expressed to Alfred D. Zapp, M. W. Harris, Elmer Kneedler,and Parke D. Snavely, of the United States Geological Survey, for their aid, data, and maps.Bauxite was discovered in the Andersonville district in 1912 on lot 187 of the 28th land district, in Sumter County. This lot is situated about 1.5 miles west of the Flint River, on the south slope of the valley of Sweetwater Creek. Mining was started in May 1914 by the Republic Mining & Manufacturing Co. This and adjacent properties were acquired in 1930 by the American Cyanamid & Chemical Corp., which has been operating there since."

Dec 1, 1949

By B Whittaker

The paper examines the role of chain pillars in longwall mining layouts as used in several countries. The application of chain pillars in relation to their expected design role is discussed. An important feature is the specification of the pillar design to meet strata loading conditions as imposed by the mining and geological setting. The paper relates longwall width and chain pillar configurations to pillar size to satisfy anticipated loading and strength expectations. Laboratory work is referred to which examines criteria for pillar stability. Comments are made regarding the application of the findings presented in the paper, to different situations involving the use of chain pillars in longwall and shortwall mining systems.

Jan 1, 1987

By G E. Ho, M Anda, S Dallas

Water auditing and water conservation measures are fast becoming the quantitative tools for water balance reporting in the mining and minerals processing sector. Therefore, this paper was written to describe the process of water auditing in a goldmining environment and to contribute towards building an appropriate water management framework for The Cooperative Research Centre (CRC) for sustainable resource processing (CSRP). The research will assist with the assessment of water balances in mining and hydrometallurgical processes and ongoing probabilistic modelling for Newmont Mining Corporation, its wholly owned gold mines, and its joint venture operation of Kalgoorlie Consolidated Gold Mines (KCGM). Kalgold or KCGM are the managers of a joint venture project between Barrick Australia (50 per cent) and Newmont Mining Corporation (50 per cent) at Kalgoorlie, Western Australia (WA). Boddington Gold Mine (BGM), Western Australia, will commence operations this year and manage the new goldmine expansion project. BGM is 100 per cent Newmont owned and will operate to continue mining gold and copper from the existing (BGM) site that was decommissioned in 2001.

Jan 1, 2009

By D. M. Doyle

"In this paper I will summarized the Falconbridge Nickel Mines1) energy costs and consumption data by fuel, process, cost centre and estimate our future costs and consumption patterns 2) detail the distribution of electrical energy 3) distribution of other forms of energy 4) describe present and planned energy conservation schemes; and 5) discuss economic justification and responsibility.There is sufficient material in this presentation to warrant several technical papers, however we felt that an overview of all our data and endeavors on the subject, would be most beneficial to those companies formulating energy conservation plans. The data briefly referred to in this slide presentation can be found in the technical paper.Over a five year period, total energy costs will vary between $63 and $94 MM depending on the future rate of energy cost escalation. An unrealistic 32% reduction in energy consumption is required to hold our own in the years ahead whereas an attainable 10°;, reduction in energy consumption would save $9 MM over this five year period.Total energy consumption, tonnage of ore delivered to plants and their ration BTU’s per ton of ore, are graphed for the years 1973 through 1976 and forecasted for the 1980’s. In 1974 we along with other member companies of the Mining Association, determined our purchased energy per ton consumption rate and set, as our goal, a 20% reduction by 1980. The dotted lines calculated from the energy audit, based on 1976 data shows there is a potential for a 10% increase in energy per ton. This could result from a lower than forecasted mining rate and operation of the new roasting, electric furnace and acid recovery facilities installed for environmental considerations at designed capacity."

Jan 1, 1978

By R. Snoby

Since its introduction in 2002, the modern air jig has processed a wide array of coals throughout the world. This paper explores the reasons and justifications for the installations and provides case history performance data. Specifically highlighted are air jig plants processing metallurgical coal in Colombia, bituminous coal in the United States and India and lignite in the United States and Spain. Each installation has unique reasons to justify an air jig facility. It is important to note that not all of the justifications were based on the ?most cost effective yield?, normally a mantra for coal preparation plant designers and owners. Dry jigging of coal has long been a proven technique for upgrading coal, the modern air jig, with its improved efficiency and operating systems simply extended the range of applications. In some cases, it even allows market quality coal to be produced when no other option is possible.

Jan 1, 2009

By W. Burger

Mechanical excavation methods can significantly improve excavation performance and labor safety compared to drill and blast operations. Herrenknecht has developed a mechanized shaft sinking method for soft and medium strength rock. This system combines innovative technologies which allow simultaneous excavation, removal of cut material and the installation of rock support. This Shaft Boring Roadheader ?SBR? is flexible in diameter and can be used in shafts with changing diameters and different shaft support requirements for depth up to 2,000 m. During regular excavation personnel are not required to access or work on the shaft bench. The boom used to cut the shaft profile is based on roadheader technology.

Jan 1, 2012

By James C. Barker

The U. S. Bureau of Mines made a reconnaissance In the western Crazy Mountains for cobalt and associated metals as part of the Alaska-wide critical and strategic metals program. The area, located about 75 miles north of Fairbanks in central Alaska, is underlain by complexly faulted, predominantly clastic sedimentary rocks bordering the Tintina Fault system. Above background metal concentrations were found to occur in altered fault zones, tectonic breccias, soils, and ground water seeps and precipitates that either cut or are derived from the faulted clastic sedimentary rocks. Up to 0.115 pct cobalt and more than 2.0 pct zinc were detected in soil samples. Spring precipitates contained up to 1.3 pct zinc, 0.037 pct tungsten, and other metals. Some localities lacked cobalt but contained anomalous amounts of copper, lead, zinc, silver, and other metals. No outcropping of primary metallic minerals was located because of Colluvium and vegetation cover and extensive deep leaching. Therefore, whether the metal values encountered are due to primary deposits with economic development potential or are the results of concentration by ground water from low-grade sources is unknown. The presence of cobalt, nickel and zinc, and the identification of minor tin and tungsten indicate that further investigation is warranted.

Jan 1, 1983

By R. Balia

The upper part of the "Contatto Ovest" orebody, at the San Giovanni Pb-Zn sulphur mine (Sardinia, Italy), is mined by a sublevel caving method. With increasing mining depth, a progressive caving of the hanging wall and discontinuous subsidence occurs. The orebody, which is located very close to the contact between the Cambrian limestones and the Silurian shales, strikes NE-SW for more than 100 m and dips 75-80' NW. The limestone footwall is massive and strong while the hanging-wall consists of very weak shales. The mine considered is located near a town so that the observed subsidence effects must be taken into account for both stability of the nearby railway and houses and morphological and environmental impact. A limiting equilibrium analysis to predict the progress of hanging wall failure with increasing mining depth was used. A suitable computer program was developed for solving the model by a iterative procedure. The progressive hanging wall caving and its consequent superficial effects were predicted perfectly by means of the computer program used and later confirmed by a geophysical test (seismic tomography). Our study ends with a further analysis, carried out using the same procedure, which allows to have a different geometrical situation with the presence of a pillar to protect the mill area.

Jan 1, 1990

By S. Vujic

The exploitation of stone (trachyte) at the ?Srebro? open pit mine, located on the northern slopes of the Fru?ka Gora National Park (Serbia) central area begun in 1964. Stone exploitation in this locality does not endanger the environment in an ecological sense, does not pose a threat to plants and animals, and apart from the terrain configuration changes, it did not leave behind permanent consequences to the environment. Projects for permanent cessation of mining operations and for land reclamation and spatial arrangement were completed in these circumstances. The paper gives a short review of the condition at the open pit mine; furthermore, the key problems and basic demands are presented, together with a concept of technical and biological land reclamation and the spatial arrangement of the mining complex. Keywords Open pit mine, land reclamation, spatial planning, spatial arrangement, National Park, Fru?ka Gora, Srebro.

Jan 1, 2011

By A. Robles-Vega

In recent years, tellurium has been extensively used in the manufacture of semiconductor materials. For this type of application, high-purity tellurium is required. Selenium, lead and silicon are usually the main impurities in tellurium. During the electrolytic refining of copper, tellurium gold and silver are collected in the anode slimes. A pyrometallurgical treatment is used to recover gold and silver from the decopperized anode slimes whereas tellurium is oxidized and skimmed off from the refining furnace as a Na2CO3-based slag. In the slag, tellurium is present as sodium tellurite (Na2TeO3), which is further water-leached from the slag. The first step in the conventional process for tellurium recovery consists of the precipitation of the tellurium contained in the leaching solution as tellurium dioxide (TeO2). The solid TeO2 is then dissolved under acidic conditions for its further reduction with sulfur dioxide gas (SO2). In this paper, an alternative route for tellurium production is presented in which a sodium tellurate [Na2TeO4] intermediate is obtained by oxidation of the sodium tellurite in an alkaline solution following the water leaching step. Sodium tellurate is then dissolved in acid media and high-purity tellurium is obtained by reduction with SO2 gas. Experimental tests under laboratory conditions indicate that the novel process yields higher precipitation selectivity for tellurium than the conventional process. A comparison of its efficiency concerning impurities co-precipitation with respect to the conventional process is discussed.

Jan 1, 2009

Jan 1, 2004

By Edwin B. Eckel

This paper, based on brief field examination and on data supplied by the operators, records the condition of the Italian mercury industry as of March 1945, not long after Italy's collapse. Except for the once-Italian but now Yugoslavian Idria mine near Trieste, virtually all the known mercury deposits are in the Monte Amiata district in Siena and Grosseto Provinces, 75 miles north of Rome. This district contains the Abbadia San Salvatore. the Siele. the Argus, and the Cerreto Piano mines besides numerous prospects and unproductive mines. Under pressure from Germany the principal mines were highly productive during the early part of the war, but production fell off long before its end. All of the mines were damaged in some way at the German withdrawal but by September 1944 the Abbadia had resumed production and several others were only lacking power by the early spring of 1945. The Monte Amiata district is characterized geologically by a thick series of sedimentary rocks that range from Triassic to Eocene in age . and are surmounted on Monte Amiata itself by a thick cap of extrusive trachyte. Bodies of travertine and of landslide detritus, younger than the trachyte, are rather widespread. The structure is complex and little known but most of the ore deposits seem to lie along or near a major, north-trending fault or on associated cross-fractures. Cinnabar is the only important ore mineral and clay minerals are by far the most abundant products of hydrothermal alteration. A southward increase in the amount of stibnite, relative to cinnabar, suggests horizontal zoning. The grade of ore ranges from 0.60 to 3.0 Pet and the reserves, as compared with those in American mines, are enormous. Even in the face of war-time scarcities, the mines are remarkably self-sufficient and labor is plentiful, but the costs of production are estimated to be not greatly below those of the better American mines. Notes on the principal mines, on the mining and metallurgical methods, and on the manufacture of synthetic cinnabar are included in the paper. Introduction With but few brief interludes, Spain and Italy, including the Idria mine near Trieste, which has passed from Austrian to Italian to Yugoslavian hands in the Past 3 decades, have led the world in the production of mercury, or quicksilver, for many centuries. Despite their enviable position with respect to the supplies of a metal so essential in both war and peace, there is a notable lack of up-to-date information in America on the mercury industry of either country. Duschak and Schuette' and Schuettez,3 give by far the best summaries in English known to the writer, but the latest firsthand report cited by them on the Italian mines was published in 1915.' Having been deeply interested in the geology and economics of mercury for several years, the writer naturally felt most fortunate in being the to obtain enough firsthand information on the Italian industry to fill at least a few of the gaps in our knowledge. The opportunity came during the war, soon after this industry, together with the rest of Italy, had capitulated to the Allies. Many of the facts presented here are thus definitely "dated," but others are of less transitory nature, and even the dated facts should be of interest in showing the strength and

Jan 1, 1949

By Edwin B. Eckel

This paper, based on brief field examination and on data supplied by the operators, records the condition of the Italian mercury industry as of March 1945, not long after Italy's collapse. Except for the once-Italian but now Yugoslavian Idria mine near Trieste, virtually all the known mercury deposits are in the Monte Amiata district in Siena and Grosseto Provinces, 75 miles north of Rome. This district contains the Abbadia San Salvatore. the Siele. the Argus, and the Cerreto Piano mines besides numerous prospects and unproductive mines. Under pressure from Germany the principal mines were highly productive during the early part of the war, but production fell off long before its end. All of the mines were damaged in some way at the German withdrawal but by September 1944 the Abbadia had resumed production and several others were only lacking power by the early spring of 1945. The Monte Amiata district is characterized geologically by a thick series of sedimentary rocks that range from Triassic to Eocene in age . and are surmounted on Monte Amiata itself by a thick cap of extrusive trachyte. Bodies of travertine and of landslide detritus, younger than the trachyte, are rather widespread. The structure is complex and little known but most of the ore deposits seem to lie along or near a major, north-trending fault or on associated cross-fractures. Cinnabar is the only important ore mineral and clay minerals are by far the most abundant products of hydrothermal alteration. A southward increase in the amount of stibnite, relative to cinnabar, suggests horizontal zoning. The grade of ore ranges from 0.60 to 3.0 Pet and the reserves, as compared with those in American mines, are enormous. Even in the face of war-time scarcities, the mines are remarkably self-sufficient and labor is plentiful, but the costs of production are estimated to be not greatly below those of the better American mines. Notes on the principal mines, on the mining and metallurgical methods, and on the manufacture of synthetic cinnabar are included in the paper. Introduction With but few brief interludes, Spain and Italy, including the Idria mine near Trieste, which has passed from Austrian to Italian to Yugoslavian hands in the Past 3 decades, have led the world in the production of mercury, or quicksilver, for many centuries. Despite their enviable position with respect to the supplies of a metal so essential in both war and peace, there is a notable lack of up-to-date information in America on the mercury industry of either country. Duschak and Schuette' and Schuettez,3 give by far the best summaries in English known to the writer, but the latest firsthand report cited by them on the Italian mines was published in 1915.' Having been deeply interested in the geology and economics of mercury for several years, the writer naturally felt most fortunate in being the to obtain enough firsthand information on the Italian industry to fill at least a few of the gaps in our knowledge. The opportunity came during the war, soon after this industry, together with the rest of Italy, had capitulated to the Allies. Many of the facts presented here are thus definitely "dated," but others are of less transitory nature, and even the dated facts should be of interest in showing the strength and

Jan 1, 1949

A mining engineer from South Africa, whose research has taken him to some of the world?s deepest gold mines, is the winner of the St Andrews Prize. Daniel Limpitlaw, 27, picked up a cheque for $25,000 for his dissertation on reversing the damage done by early mining technology, which he claims is partly responsible for blighting the urban environment in many South African cities. Launched in October 1998 by the University of St Andrews and international energy company Conoco, the St Andrews Prize sought practical solutions to environmental problems. It attracted interest from 450 individuals and groups from countries as diverse as China, Pakistan, Canada, New Zealand, Germany, the UK and the United States.

Jan 1, 1999

By G. Taylor

"The Iron Ore Company Of Canada's Carol Project is located in Labrador City, Newfoundland. Labrador City is some 912 air kilometers northeast of Montreal, and 417 ratl kilometers north of Sept-Iles, Quebec.Over 2,800 employees work at the Carol Project to produce some 20.0 million tonnes of concentrate and 10.5 million tonnes of pellets annually.In 1979 our Training Department started to develop the DACUM System of training for our Concentrator Operations Department.DACUM is an individualized, self-learning, training program. It is both a curriculum plan and an evaluation instrument.To date, the DACUM System has been completed for all occupations in the concentrator and work will commence shortly to develop DACUM for our Pellet Plant and Mine Operations Departments."

Jan 1, 1982

By C. J. Farrow, M. J. Smith

"Bechtel has managed a number of test programs to establish autogenous grinding circuits and size mills for a variety of ores.This paper outlines the procedures whereby bench scale and pilot plant tests are used to select the most efficient circuit to grind the range of ore types likely in the mill feed.Five examples are given. One example traces the development of a pilot plant program; it shows how bench scale Work Indices provide a target for the grinding power requirement of an ore and relates how pilot circuits are changed as a result of interpreting the results from preceding tests. The other four examples relate the interpretation of the test results to provide design data; they illustrate a number of phenomena which have been observed.INTRODUCTIONConventional crushing and grinding circuits can be specified from bench scale test data such as Bond Work Indices. Bond Indices have been correlated to a large number of rod and ball mills and by applying appropriate factors, mills can be sized from the Work Index.For autogenous or semi-autogenous grinding circuits, bench scale tests are not sufficient to be able to specify the circuit and size of the mills for a commercial plant. It is necessary to run a series of pilot plant tests to determine how the ore behaves."

Jan 1, 1982

A model has been developed as part of the AMIRA P420 Gold Processing Technology Project to simulate the recovery of gold by centrifugal gravity devices. The model (which is available online) uses the simulation methodology developed by Laplante et al (1995) to predict gravity recoverable gold (GRG) recovery under varying operating conditions and circuit configurations. In addition to predicting GRG recovery, the model also predicts the GRG content and size distribution of the cyclone overflow and underflow. The predicted overflow GRG content and size distribution can be used as inputs for a leaching model in which size dependent leaching rates are applied for each size class of GRG and non-gravity recoverable gold (non-GRG) in the cyclone overflow, allowing size-by-size leach recoveries to be determined for GRG and non-GRG. The application of the gravity model and leaching model are demonstrated using a case study. The simulated gravity recovery and leaching performance showed excellent agreement with the measured values. The developed models can be used to assess the sensitivity of gravity gold and leach recoveries to varying feed GRG content, GRG size distribution, gravity circuit feed rate, classifier performance and leach residence time. The described methods can be used to optimise new and existing gravity and leaching circuits.

Aug 1, 2010

By Bruce Pinkston

This report presents a description of the Prototype Demonstration Vehicle developed under U.S. Bureau of Mines Contract No. JO 366003, "Improving Man Transit Safety". This vehicle was constructed to assess the feasibility of a set of equipment related guidelines which were drafted in Phase I of the same contract. State-of-the-Art improvements were embodied in such areas as collision survivability, occupant comfort, and multiple mode (on and off rail) operation. The electric battery-powered vehicle carries a twelve man section crew at speeds up to 12 mph. The description of the demonstration vehicle is presented in Volume I. Safety Guidelines are presented in Volume II.

Jan 1, 1981