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By R. O. Pynnonen

Tunnel-driving is recognized as a hazardous occupation; adequate support of roof and sides for preventing accidents from falling material is usually one of the most important safety problems. Where extraordinary conditions of sand and water are found, this problem becomes even more difficult. Tunneling at the Tioga No.2 mine was stopped when a 22-foot bed of water-saturated, fine gray sand was encountered. The tunnel, designed to house an ore-conveyor belt, was being driven from both ends. Driving was extremely difficult at both the upper and lower faces when the sand horizon was reached. A distance of 178 feet remained between the faces. Heavy pressures deformed the steel-supporting rings at the upper face, and there was an inrush of mud and sand at the lower face.

Jan 1, 1958

By F. E. Cash

Much has been written concerning accidents in coal mines; the fact that accidents cost the employer and employee money is generally well known, but how much accidents actually cost is vague, even in the minds of many operators. Unquestionably there are hazards in coal mining, but many of them can be eliminated; and from the prevention of accidents there can be realized a material saving in dollars and cents as well as in human suffering. In presenting the frequency, severity, and cost of accidents in some Tennessee coal mines, it is hoped that other mines in Tennessee, as well as mines in other States, will by a comparison of the data with their own ex¬ perience be enabled eventually to reduce the number of' their accidents.

Dec 1, 1932

By Mark Sanders

This report describes an experiment which was conducted to compare the relative bumping hazard of a low and high profile hard hat (helmet) in a low seam mining environment. The study was specifically designed to assess the effect of lowering the helmet profile on frequency of head impacts in an underground low seam coal mine simulator. This involved subjects performing four common low coal mining tasks wearing the low and high profile helmets in the low seam simulator (36" and 48? heights). The results of the study indicated that a low profile helmet could reduce bumping frequency in underground low coal approximately 25%, and as much as 80% on selected tasks. It was beyond the scope of the study to measure the impact force, thus it was not possible to estimate the effect of the low profile helmet on severity of impacts underground. The research team recommended that a more extensive investigation be made of head injuries experienced in low seam mining (both underground and surface) with the objective being to assess the impact of a low profile helmet on total head accident exposure.

Jan 1, 1980

By C. E. Hennig

On January 1, 1961 there were 311 petroleum refineries in the United States with a total crude-oil throughput capacity of slightly more than 10 million barrels per day, according to the Bureau of Mines' annual survey. Compared with a year ago, this represents net increases of one in the number of plants and 109 thousand barrels per day in total capacity. Contributing to this increase was the completion of two new plants, one in Hawaii and another in Michigan, during the year. At the beginning of 1961 the industry was building facilities which will increase this overall crude capacity by 36,500 barrels per day. As part of its building program, it was also replacing 329,000 barrels per day of its present capacity. Of the total 10 million barrel per day installed capacity, the industry reported 380,000 barrels per day as being shut-down on January 1, 1961. This included 11,500 barrels per day considered inoperable without extensive reconditioning.

Jan 1, 1961

By George T. Faust

The petrographer engaged in examining the products resulting from the beneficiation of ores and rock minerals is constantly required to develop new means and methods of assaying microscopically the results of such operations. From time to time investigators have published descriptions of apparatus that have aided in solving problems in processes f physical separation. Thus, in 191.9, Coghill and Bonardi 31 published a paper covering the application of the binocular microscope and camera lucida to the microscopic analysis of pulverized ores. Similar work has been published by Schneiderhohn 4/, Schwartz 5/, and Head and his associates6/, 7/, 8/. The present paper goes further and considers application of the polarizing comparison-microscope to problems directly concerned with mineral dressing where it is desirable to compare analogous products, and in addition it suggests new uses in various related fields. This work was conducted under the cooperative agreements of the Southern Experiment Station of the Federal Bureau of Mines and. the University of Alabama.

Jan 1, 1940

By Edward A. Barrett

The ability to recognize visual cues commonly associated with roof and rib hazards is fundamental to the prevention of groundfall accidents. The perceptual skills that miners possess to visually search and assess hazardous ground conditions differ considerably. This U.S. Bureau of Mines report summarizes recent investigations on the use of stereoscopic (3-D) slides as a training aid for improving the ability of miners to recognize the various geologic and mining-induced irregularities that cause ground-falls. The feasibility of using 3-D slides for training and their effectiveness for representing roof and rib hazard conditions are discussed. Information is presented on equipment and procedures for creating a 3-D slide program that can be updated by mine trainers. Recommendations are made on selection of 3-D equipment and on the use of 3-D slides for training miners to recognize roof and rib hazards.

Jan 1, 1988

By A. G. Sharkey

THE PURPOSE of this investigation was to develop methods for analyzing coal derivatives and products from the Fischer-Tropsch synthesis. As part of this investigation it was necessary to study the mass spectral characteristics of many classes of compounds. The mass spectra of alcohols, the trimethylsilyl ether derivatives of alcohols, acetal-type compounds, ketones, esters, and naphthenes were correlated with structure, and analytical methods were formulated. A method was devised to determine the ratio of branched to normal hydrocarbons up to CIS in the Fischer-Tropsch product. Low-ionizing-voltage mass spectrometry was combined with type-analyses to analyze tar acids and neutral oils from coal. The necessary sensitivity correlations at low-ionizing voltage were developed, particularly for phenolic compounds. Special analytical techniques were developed for the mass spectral analyses of specific compounds and compound types including (1) oxides of nitrogen, (2) hydrogen sulfide, (3) isomers of butenes and pentenes, and (4) hydrogen deuteride. An investigation was made of the effects of various hydrocarbons and oxygenated compounds on tungsten filaments in the mass spectrometer. The operating characteristics of rhenium filaments under similar conditions were studied. Several improved sample handling techniques were developed, including an automatic manometer and a self-filling micropipet. Studies were made of anomalous and negative peaks in the mass spectra of certain gases.

Jan 1, 1967

By Kenneth R. Sites

Under this program two tape recording and triggering systems were developed and delivered for use in the Bureau of Mines microseismic program. The systems are designed to improve the effectiveness of the Bureau owned Sangamo 3500 series and SABRE VI instrumentation tape recorders. The system is designed to capture random microseismic data, digitize and temporarily store these data, start the tape recorder; and then transfer the data to magnetic tape for permanent storage. The system is designed to pack data on tape such that the tape may be simply played back through galvo drivers onto an oscillograph such that a continuous series of analog records, with corresponding time of day information, are reproduced without excessive oscillograph paper waste or the need for the operator to search for valid events.

Jan 1, 1980

The strippable reserves of bituminous coal and lignite in the United States were calculated in accordance with the prevailing conditions of seam thickness and depth of overburden in each of the several coal-producing areas of the Nation. Within defined limits of seam thickness and depth of overburden, it is estimated that there was a remaining strippable resource of 118 billion tons of raw bituminous coal and lignite as of January 1, 1968. Because of topography, natural and manmade features, and other limitations, only 45 billion tons of the resource are strippable reserves. Of this, 32 billion tons is considered low-sulfur (less than 1 percent), 4 billion tons is medium-sulfur (1 to 2 percent), and 9 billion tons is high-sulfur (over 2 percent) coal. Owing to a cleaning loss affecting that portion of strip coal that is mechanically cleaned, the 45 billion tons of strippable reserves are reduced to 39.6 billion tons of marketable coal. A brief discussion is given for each coal-producing State, summarizing past and present production, historical background, and outlook. Appendix A contains reserve data by State, county, seam, and sulfur content. Appendix B contains the general information and requirements necessary to comply with the current strip mining laws covering 20 States.

Jan 1, 1971

By Richard H. Oitto

The Bureau of Mines and Kaiser Steel Corp. are cooperatively demonstrating the shield-type roof support in the longwall mining of a 10-1/2-foot-thick coalbed at the York Canyon mine near Raton, N. Mex. As part of the demonstration, the shield supports have been successfully and safely moved from a completed longwall face to a new longwall face. When these shield supports were moved in 1976 they were the largest and heaviest longwall support system in use in U.S. coal mines. The shield supports, preparations for moving them, the actual move, and installation at the new face are discussed.

Jan 1, 1977

By R. B. Corbett

"INTRODUCTION Aluminum and manganese bronzes as a group, may be separated readily from other copper-base alloys by experienced sorters. However, separation of aluminum bronze from manganese bronze is generally a matter of guesswork, so that accurate separation presents a difficult salvage problem.Attempts at separation by the thermoelectric tester. 3/ which had proved successful in solving other sorting problems, showed in this instance that the desired separation was uncertain because of the wide range of composition allowable in each kind of bronze. If only one composition of each kind of bronze were used in industry, separation by the thermoelectric method probably would be simple. However; the variability in composition observed in commercial alloys is so great that the thermoelectric power of the one type frequently overlaps the range of values found for the other. As a result, specimens frequently are classified in the' wrong group.Separation of the two types of bronzes on the basis of measurements of magnetic properties on filings from the various samples also proved unsuccessful because the test results overlapped to such an extent that no clear-cut division could be obtained.Electrode potential measurements were made also on the aluminum and manganese bronzes in the hope of distinguishing between them. A drop of saturated potassium chloride solution was placed on the fresh surface of the metal and the tip of a calomel electrode introduced therein. The voltage generated was measured by connecting the electrode and the bronze part to a research-type potentiometer. Although the voltages generated by the manganese bronze parts were greater than those generated by the aluminum parts, the difference in the closest two sets of readings was not sufficient to warrant a good separation. When a concentrated potassium alum solution was used instead of the potassium chloride solution, a wider divergence of voltage was produced by the various bronzes, but unfortunately readings overlapped in several instances."

Nov 1, 1944

By F. S. Crawford

This report deals with the effectiveness and economy of installing mine timbers treated with preservatives in long-life service locations. Early in the present century, when mine timbers and labor were plentiful, it was not general practice to install treated timbers in such places. Because national sources of good mine timber are declining steadily, the mining industry must now conserve timber. Moreover, the cost of installing and replacing mine timbers has been rising. Therefore, even the simplest of treatments can be expected to give some return on the investment when applied to timbers that are to be installed in relatively permanent locations. Better methods of treatment will produce better returns. In a service test of maple timbers treated by the hot-and cold-bath method and installed in main haulageways of the Athens mine of the Cleveland Cliffs Iron Co., Negaunee, Mich., zinc chloride-treated timbers had an average useful life of 13.3 years; borax-treated timbers, 11.2 years; and sodium fluoride-treated timbers, 7.7 years. Untreated timbers used as controls had an average useful life of 3.8 years.

Jan 1, 1950

By D. Randolph Berry

Volume II contains appendices which explain and document the recommendations of Volume I. The following topics are covered: Appendix A Discussion of Recommended Guidelines Appendix B Worldwide Use of Oxygen Self-Rescuers Appendix C Hypothetical Use of Oxygen Self-Rescuers in Post-1972 Coal Mine Explosions and Fires Appendix D Vibration Testing of SCSRs Appendix E Testing of In-Service Chemical Oxygen SCSRs Appendix F Discussions with Representatives of Underground Coal Mining Appendix G Recommendations for SCSR Storage Containers Appendix H Example SCSR Storage Plans Appendix I Testing of In-Service Compressed Oxygen SCSRs Appendix J 30 CFR 75.1714, 30 Regulations Pertaining to Self-Rescuers

Jan 1, 1981

By J. P. Barkley

"The accompanying tabulation gives the results of a series of operating tests on two types of small stokers. One was an inclined, natural-draft, moving-grate, overfeed ""hand-stoker"" fired and manipulated by hand; the other was. a horizontal, forced-draft, stationary-grate, underfeed, mechanical unit-stoker operated by an electric motor. These were installed as shown by the accompanying sketches (figs. 1 and 2) under horizontal return tubular boilers of a nominal rating of 150 bl.h.p. each.The steam load carried by these boilers was a rather typical heating load. It was fairly constant and of about 30 bl.h.p. throughout the summer months, with small variation between day and night. During the winter months the daily variations were dependent upon the outside temperature. The boilers were banked a considerable part of the night.As noted in the table, two kinds of coal were used. The size of one kind was run-of-mine and the other 11/4 inch nut and clack. These coals from two different mines of the New River district both caked considerably during burning, the nut and slack more than the other. Analyses of the coal were as follows:"

Jun 1, 1929

By Douglas Talley

This report describes a 4-inch diameter borehole probe which contains a low light level TV camera, magnetic compass, light illumination source, bottom/water detector sensor and a pointing angle sensor. The camera viewing angle is at a right angle to the probe's body. All data from the sensor is multiplexed into the closed circuit camera video for transmission on a single 50 ohm coaxial cable to a surface control unit. Likewise control of the probe's power, zoom lens, focus, panning and aperture is accomplished via a down-link multiplexed on the same cable.

Jan 1, 1984

By A. Z. Dimitroff

An improvised rock-dust disseminator, consisting of a 10-gallon galvanized metal milk can that dispenses rock dust in return air currents by the injection of compressed air has reduced the float dust explosion hazards at the Koehler coal mine, Koehler, N. Mex.

Jan 1, 1965

By Richard A. Andre, R. Larry Grayson, Thomas Simonyi

"INTRODCICTIONThe search for the cause(s) of coal workers' Pneunoconiosis continues despite the vast amount of research that has been undertaken over the past forty to fifty years. Good correlation between the mass of dust inhaled over workers' lifetimes and the incidence of the disease has led to the development of effective environmental standards and implementation of good procedures for the control of dust generation and dispersion in the working place. Research has only begun, however, to uncover the biochemical mechanisms involved in initiating the disease.Correlation between the rank of the coal seam in which miners worked and disease incidence and severity is acknowledged worldwide, but the agents in the higher rank coal seams which cause CWP arc still not defined. The basic components of the coal seams, i.e., the elements and minerals, are generally known, but the way in which they interact with human pulmonary cells is largely still a mystery.The process of disease development is a biochemical one which depends on the characteristics of the pulmonary cells within their immediate biochemical environment and the characteristics of invading respirable coal mine dust particles, probably both chemical and physical ones. The cell-particle relationship, therefore, must be defined, and both cells and particles must be characterized according to properties which potentially are involved in the disease process.Following such characterization, specific respirable dusts from different coal seams, which appear to have different effects on coal workers, must be obtained or constructed and then used in experiments designed to determine dust toxicity or the response of animals exposed to the dusts.The results presented here focus on characterizing properties of respirable coal mine dust particles collected from operating longwalls in West Virginia and Virginia Longwall panels were selected for analysis because the respirable dust in the coal face areas is largely uncontaminated by rock dust and analysis of the dust yields results unconfounded by rock dust."

Jan 1, 1990

By Virginia E. Gleason

In this report, recommendations are made for programs to develop workable techniques to stop or prevent acid mine drainage formation in those underground coal mines where acid production could take place. These recommendations include development of mine closure technology, development of surface water infiltration control procedures, study of the effect of roof collapse on mine water characteristics, evaluation of the long-term effects of flooding underground mines above drainage, investigation of the effectiveness of section sealing in active mines, development of a simple model for predicting mine water quality and quantity, preparation of a manual on mine drainage abatement procedures, and development of a program to disseminate information on mine drainage abatement to the coal industry. These recommendations are based on an in-depth evaluation of information acquired over years of research on acid mine drainage formation, on numerous laboratory and field studies of methods of preventing or minimizing acid mine drainage formation, and on review of the geological, hydrological, and mineralogical factors involved. There are 772 references.

Jan 1, 1978

By J. W. Paul

This paper deals with the second phase of an extensive research on coal-mine ventilation factors. A comprehensive report of the entire work is in course of preparation, but abstracts of the various chapters are being prepared in order to make the results public as rapidly as possible. Part 1 dealt with the resistance of unobstructed entries and was issued as Serial 2621 of the Bureau of Mines, in July 1924. Description of tests. After the resistance of an unobstructed entry to flow of air had been determined by tests in the Experiment mine, mine cars were; run into the test section in various arrangements and the increase in resistance was determined. The cars used were of the wooden type with loose end gate, and would hold about one ton of coal, level full. They were 7 feet long. 4 feet 2 inches wide above the wheels, 3 feet high, and had a cross-sectional area of approximately 10 square feet. The average area of the entry was about 57 square feet, the ratio of unobstructed to total area being about 17.6 per cent. The track gage was 42 inches and the wheel-base 20 inches.

Jan 1, 1924

By A. W. Ambrose

"A need exists for men in oil-field production work who correspond to the mining engineer of a large mining property. Some oil companies prefer to call such an employee a resident geologist, resident engineer, or a petroleum technologist. He should perhaps be more correctly termed a petroleum production engineer. The duty of such a man is to apply his scientific and geologic training practically to oil-field development work.He should be, by education, a mining, civil, or mechanical engineer, with a knowledge of geology and chemistry. Upon completion of his education, such a man should spend several years in the oil-fields. There are two means of gaining proper experience. The first method is to work for an oil company in making a detailed study of each well, collecting data on the history and production, followed by a preparation of good records, from which well logs can be prepared. From the well logs, the geologic cross-sections, peg-models, and structure contour maps can be made. These allow a comparable, detailed study of each well, which is necessary to solve many of the problems. Along with this the engineer should visit drilling wells daily for collection of samples of formations and for a proper study of how they drill. He should form friendly relations with the drillers and production foremen. The second method of gaining proper experience is to start work as a roustabout, pumper, or on the pipe¬line gang, finally working up to a tool-dresser. After three or four years of such work, the engineer may be classed as a petroleum production engineer."

Jan 1, 1920