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By Thomas Fraser, E. A. Holbrook

The data in this bulletin were obtained during an investigation of screening practice by the University of Illinois engineering experiment station and the United States Bureau of Mines under a cooperative agreement between them and the State of Illinois Geological Survey Division. Earlier work on this subject includes a study of the general practice of coal preparation in Illinois, made in 1914 and published in 1916/ and an investigation of Illinois coal-w.ashing methods, results of which were published in 1912 in a bulletin 2 that contained complete information on the methods then in use for sizing washed coa 1.

Jan 1, 1925

By R. A. Meister

The study on improving surface coat refuse disposal site inspections included surface inspections of 15 refuse disposal sites. Monthly aerial photos were taken of the sites and computer methods were used to determine elevation changes. Photogrammetric techniques that were used are described in detail. A comparison of the results of each of these inspection techniques is included. A detailed evaluation of the photogrammetric techniques was made and conclusions were drawn concerning the advantages and disadvantages of using aerial photography and photogrammetry as part of the inspection procedure. Operators' opinions of the aerial photography methods are included.

Jan 1, 1980

By Gene R. Reid

The contract objective is the development of an Automatic Fire Control System for Mobile Underground Metal Mining Equipment. The Phase I Report, which described the projected data handling plan, was published on July 24, 1975. The Phase II effort covered the period from July 24 through December 2 and accomplished the following objectives: ? Acquisition of data in accordance with the project data handling plan. Data were acquired through visits to twenty mine sites in ten states and Canada; visits to Bureau of Mines and MESA facilities; visits to mobile equipment manufacturers; and an extensive literature search. ? Analysis of accumulated data which provided the following specific types of design inputs: selection of the type of mobile underground equipment found to represent the greatest overall fire hazard; typical operating conditions for the vehicle; characteristics of the reported fire experiences; and performance, cost and maintenance factors affecting potential purchases of automatic fire control systems for underground mining equipment. ? Development of the AFCS design concept. Utilizing the data analysis results and considering the state-of-the-art of fire control system components, a recommended design concept was developed with particular emphasis placed on the need for a low cost and reliable system. Design trade-off studies are provided for the recommended system and for four alternate system concepts.

Jan 1, 1975

By D. Harrington

Hatch (260) made the following pertinent statement regarding the present status of engineering design of dust-control equipment: Textbooks on ventilation and engineering handbooks devote little or no space to methods of control of industrial dust, and in the technical journals papers on fundamental engineering design of equipment are conspicuous by their absence. In a recent bibliography of the literature on pneumoconiosis less than 1 percent of the articles dealt with the engineering control of the disease. The science of dust control has not developed beyond the stage of trial and error, and the design of structures for the suppression of dust is based almost entirely upon empirical data together with one or two elementary formulas. The latter were derived from the generalized experience in a limited number of Industries such as woodworking, where conditions and requirements are not at all like those, for example, in a sand-pulverizing plant. Wide experience and good judgment are essential to the proper use of the scanty information that has been collected and systematized. Without attempting to minimize the importance of experience in engineering design, it is necessary to point out that most of the past experience obtained in the empirical design of dust-control equipment was not evaluated by means of quantitative studies of the actual reduction in dust , fence, past experience does not necessarily furnish the proper guide for future design. In fact, recent surveys in certain industries, employing modern methods of investigation, have shown that existing equipment is in many cases inadequate.

Jan 1, 1935

By R. W. Stahl, H. E. Sanford, J. B. Benson

Immediately following the capitulation of Germany in World War II, the German State was occupied by various allied forces, who supervised all indus- trial activities in the area. Coal production is vital to the industrial life of Germany, and most of the coal is mined in the American- and British- occupied zones of western Germany. The British-occupied zones include the Aachen and Ruhr districts, from which approximately 90 percent of the coal is obtained. Figure 1 is a map of the Ruhr district. Because of the magni- tude of the task of insuring an adequate supply of coal and the necessity for united action, it was deemed best to reorganize the coal-producing facilities in the British zone undor the joint supervision of American and British authorities. As a result, the UK/US Coal Control Group was established accord- ing to the organization plan indicated in figure 2. Headquarters for the group was established at Essen, in Villa Huegol, the prewar home of the Krupp family (fig. 3). One of the many problems recognized immediately by the UK/US Coal Control Group was the necessity of preventing disasters and reducing accidents to work- men in mines undor military-governmont control. Consequently, the United States Bureau of Mines was requested to furnish the services of qualified men to search for the hazards incident to coal mining and to prepare comprehensive reports on the results of their investigations. The authors, who wore selected for this task, spont about a year in Germany and visited all except a few of the smaller mince. Whereas their principal purpose was to investi- gate safety conditions, somo of the operating conditions and practices also wore studied. The results of the studies and investigations are embodied in this circular with the hope that some useful information will be disseminated to the mining industry of the United States, including supervisory officials, safety directors, engineers, and mine workmon.

Feb 1, 1950

Contract No. H0110929 was awarded by the U.S. Bureau of Mines in February, 1971, to DeTer Company, Incorporated, of Mountain Lakes, N. J. The contract provided for the modification of the contractor's Model 5000 Pressure Foam Generator to fit it for the suppression of coal dust in mines, a detailed testing program in a working coal mine, and for additional modifications and testing for the suppression of fires in coal mines. The contractual program was completed in April, 1972. The results of the dust suppression tests showed conclusively that the modified DeTer equipment effectively reduced the level of respirable dust in a working coal mine well below the present and future acceptable levels set by the Mine Health and Safety Act of 1969. The fire tests, carried out in a simulated mine entryway erected on the surface, demonstrated the ability of the DeTer equipment in suppressing fires of varying degrees of severity within an acceptably short time.

Jan 1, 1972

By R. R. Sayers

That the maintenance of proper air conditions is a most important factor in the control of occupational hazards is shown by the large amount of material presented each year through the technical journal's on the effects on workers of injurious dusts, gases, and variations in temperature and humidity.. SUMMARY OF RECENT LITERATURE ON EFFECTS ON WORKERS OF EXPOSURE TO DUSTS The subject of the control of dust and dust diseases continues to be a matter of serious concern in most of the industrial countries of the world, as indicated by the following summary of reports published in a number of foreign countries as well as in the United States. Australia. The Workmen's Compensation Act of 1920 for New South Wales3 provided for the promulgation of schemes for the compensation of workers dis- abled by silica or other dust. In 1924 the prevalence of silicosis and tuberculosis among Sydney stonemasons, quarrymen, sewer miners and rockchoppers was investigated by a Technical Committee of Inquiry, appointed upon the recommendation of the New South Wales Board of Trade. The findings of this committee were published by the Government in 1925. No scheme was promulgated by the Government and in 1926 the Act was amended limiting its scope to workmen disabled by disease caused by silica-dust. This was promulgated and gazetted on September 16, 1927, and applies to men working in sandstone as stonemasons, quarrymen, rockchoppers, and sewer miners in the County of Cumberland.

Feb 1, 1931

By Jr. Boyle

This report analyzes the availability of chromium in the form of ferroalloy products (high-carbon and low-carbon ferrochromium and ferrochromium-silicon) and chromite products (metallurgical, chemical, refractory, and foundry sands) in market economy countries (MEC's). A total of 873.5 Mmt of in situ material, containing 202.5 Mmt of chromium, in 10 MEC countries was analyzed for availability as of the January 1989 study date. Extraction and beneficiation of this in situ material would result in 475.4 Mmt of marketable chromite products. As analyzed, 288.5 Mmt of these chromite products would be available for export or for internal chemical and refractory use and 186.9 Mmt would be smelted in-country to produce 74.3 Mmt of high-carbon ferrochromium, 3.9 Mmt of low-carbon ferrochromium, and 2.0 Mmt of ferrochromium-silicon, all available for export. A network flow model, which includes centrally planned economy countries (CPEC's), was also constructed to analyze world chromium supply and demand interactions for the period 1986 through 1994 and to address a hypothetical North American embargo on direct imports of all South African chromium products beginning in mid-1990. The model shows capacity constraints developing in the MEC high-carbon ferro chromium industry in 1987 and a possible subsequent overreaction by the industry in terms of new capacity additions. The results suggest that sufficient chromium is available to North America should an embargo on direct imports from South Africa be imposed by its governments. However, the effect on export revenues in South Africa is relatively small, and timely increases to world ferrochromium, chemical chromite, and foundry sand chromite capacities would be required.

Jan 1, 1993

By J. Clark

The objective of this study has been to determine the state of the art in underground, thin-seam-mining systems, to identify new technology and procedures that would reduce the hazards of thin-seam mining and to recommend areas for further research. The study was carried out in two phases, the first of these being devoted to a survey of authoritative literature. Subsequently, the practices adopted in the various mining countries were analysed and comparisons made to identify machines and methods with the potential for application in the USA. Published figures on US bituminous coal reserves show the high proportion contained in thin seams and US accident statistics demonstrate that the risk is greater in thin-seam operations. A comparison has been made with the experiences of foreign operations. The Phase 11 study proceeded along two separate avenues to examine the distinctive problems associated with seam thicknesses above and below 30 in. Current systems of mining appropriate to seams greater than 30 in were elaborated and compared by means of a simulation exercise in terms of safety, production and cost. For seams below 30 in, less conventional systems, some presently disused, were studied and their potential evaluated; the research and development work necessary to make them viable has been indicated.

Jan 1, 1980

By D. D. Hamilton

The ISMS program provided for the development and demonstration of equipment modifications in both conventional and continuous coal mining systems. This report describes activities during the demonstration of the continuous equipment and includes machine performance, results of data gathering, system evaluation, and recommendations for implementing improvements.

Jan 1, 1976

The revised inspection standards or recommendations herein have been prepared for use in Federal inspection of bituminous-coal and lignite mines. They succeed a compilation of similar standards published as Bureau of Mines Information Circular 7268 in December 1943 and employed as a guide in Federal inspections since that time. Important alterations and additions have been made because of changes in mining, practice and temporary shortages of some safety equipment; moreover, several previous standards have been found not generally applicable and have accordingly been deleted. Mining methods and equipment continue to change, and new hazards and new safeguards are introduced. Consequently, these standards are subject to revision from time to time. Questions from the coal-mining industry regarding these standards and suggestions as to changes and additions thereto will be welcomed and considered carefully when the next revision is made. Many constructive criticisms from the mining industry have been considered in preparing this edition.

Jan 1, 1945

By R. J. Evans

The generation and disposal of solid waste from electric utility plants using a lime or limestone wet-scrubbing system and the potential effects on the environment were estimated for 1975 and 1980. The study indicated that in 1975 approximately 5.8 million tons of desulfurization solid waste (50 percent solids) will be generated. In 1980, when it is estimated that desulfurization will become commercially accepted, approximately 71.4 million tons of this material will be generated for disposal and/or utilization. The desulfurization waste material when combined with lime, fly ash, and water may have potential for use as a roadbase material, landfill reclamation, and synthetic aggregate.

Jan 1, 1974

By Scott W. Hazen

COMPREHENSIVE summary is presented of results of several years of research at the Bureau of Mines Mining Research Center at Denver on adapting and applying techniques of statistical analysis in mine and mineral-deposit sampling and in computing grade and tonnage of ore for a mineral deposit. In addition to elementary statistical theory the material presented in the bulletin includes: (1) Certain special statistical techniques that have been found useful in mining applications; (2) problems, implications, and limitations that may be encountered in applying these techniques in mine sampling and evaluation; and (3) numerous examples to demonstrate application of the theory and techniques.

Jan 1, 1967

Mine waste and mine reclamation are topics of major interest to the mining industry, the government and the general public. This publication and its companion volume are the proceedings of a conference held in Pittsburgh, April 19-21, 1988. There were nine sessions (50 papers) that dealt with the geochemistry, hydrology and problems of mine waste and mine water, especially acid mine drainage. These comprise Volume 1. The nine sessions (43 papers) that dealt with reclamation and restoration of disturbed lands, as well as related policy issues, are included in volume 2. Volume 2 also contains the ten papers that pertained to control of subsidence and mine fires at abandoned mines. Poster session presentations are, in general, represented by abstracts; these have been placed in the back of both volumes.

Jan 1, 1988

Numerical models play a significant role in the design of safe underground mining excavations and support systems. Advances in the capabilities of numerical modeling software, together with ever increasing computational speeds, have made it possible to investigate the very nature of the large-scale rock mass and its response to mining excavations. The improved understanding of the rock response obtained from modeling enhances our designs, resulting in greater stability and safety of the mining excavations. To help advance the state of the art in this field, the National Institute for Occupational Safety and Health organized the International Workshop on Numerical Modeling for Underground Mine Excavation Design. The workshop was held in Asheville, NC, on June 28, 2009, in association with the 43rd U.S. Rock Mechanics Symposium. The proceedings include 10 papers from leading rock mechanics and numerical modeling experts in the United States, Canada, Australia, and Germany. The papers address a wide range of issues, including various numerical modeling approaches, rock mass modeling, and applications in coal and metal mines.

Jun 1, 2009

By Julie N. Walker

This U.S. Bureau of Mines report reviews the first 2 years of the agency's progress in implementing total quality management (TQM), which the agency refers to as Quality Improvement (QI). All employees have been trained in basic TQM concepts, a cadre of facilitators has been selected and trained, and 13 Bureauwide teams are addressing specific issues that were identified by Bureau employees nationwide as problem areas. Also in place are a Quality Council composed of the Bureau's top executives, a Quality Management Board, and eight QI Working Groups to provide a national 01 infrastructure. There are also Quality Steering Groups at each Bureau location nationwide to address local concerns. In addition to the narrative text, the texts of salient memoranda and other documents are included as appendixes.

Jan 1, 1992

By Edward P. Barrett

SPONGE IRON has been defined as the metallic product formed by the reduction (removal of combined oxygen) of iron ore or other iron oxides at temperatures below the fusion point of iron. This product probably derived the name "sponge iron" from its porous nature. When the reduction proceeds at slightly higher temperatures and the particles of metal weld together or finally even melt to yield pellets or balls that lack the porosity and low-density characteristic of sponge iron, the product might more correctly be called "direct iron."

Jan 1, 1954

By Larry G. Stolarczyk

This report deals with information regarding a new Medium Frequency (MF) Wireless Communication System for underground mines. This new telecommunication system works on low loss electromagnetic wave propagation modes which allow it to provide quality radio communications almost anywhere in a mine. Tests show the MF system can provide improved safety and managerial control, increased productivity, better organizational team-work and reduced maintenance cost; furthermore, MF's unique design allows for easy installation at a minimum cost. This paper covers the following: 1) MF design plan, 2) Overview of mine radio communications systems, 3) Preparations needed for designing an MF system, 4) MF equipment, 5) MF installation, 6) MF design considerations, 7) MF design specifications, and 8) Recommendations dealing with MF system. Experiments in four mines are illustrated to demonstrate the success and viability of the MF system. The mines range from small (500 tons/day) to large (67,000 tons/day) capacity and represent several different mining methods. The MF Wireless Communication System represents an advancement in mining communication and the groundwork for other advanced mine systems.

Jan 1, 1984

Fresh coal refuse was sampled at 21 US mines. Five of the sites were drilled, sampled and tested more extensively. Field tests included Standard Penetration tests, and in-situ density determinations. Laboratory testing included specific gravity, gradation, maximum, and minimum density tests, as well as 9-inch) drained triaxial tests, 9 and 10-inch, permeability tests, slake-durability tests, and accelerated slaking tests. Some refuse sites had significantly lower shear strengths and permeabilities in old, slaked or weathered material than in fresh refuse. Testing did not show useful correlations between strength and permeability changes and other material properties which could serve as "predictors". Testing of refuse under "accelerated slaking" conditions showed promise as a comparative tool and as a potential means of preparing artificially aged samples for evaluations of long-term behavior. The state-of-the-art in slaking research, and the implications of slaking on coal refuse disposal, and on practical methods of managing slaking, were also studied.

Jan 1, 1981

By A. C. Fieldner

This report is the fourth of a series of annual summaries of research and technologic work on coal by the Technologic Branch of the Bureau of Mines. The coal research program of the Bureau has been broadened and made more flexible to adapt it to changing conditions and needs of the coal industry, and as a result information as to the properties and composition of coal has been increased and new and improved practices in mining, preparation, and utilization of coal have been devised. The present

Jan 1, 1940