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By Robert H. Peters

This report presents a literature review conducted by the U.S. Bureau of Mines. The review summarizes what has been learned from recent empirical studies of the relationship between mine safety and characteristics of miners, mine management, and mining companies. The review is based on literature published in the United States during the period from 1976 to 1988. In addition to summarizing the empirical findings, this report discusses the implications and limitations of these studies, and gives recommendations for improving mine safety. An annotated bibliography section appears in the appendix.

Jan 1, 2009

By Irving Hartmann

[The explosability of coal dusts has been the subject of many investigations studies have been conducted in laboratories, in galleries and in coal faire; of several countries to obtain information on the causes, development, and prevention of mine explosions. Early laboratory experiments on it American colas dealt with pressures developed in test bomb by explosions of dust clouds and with, the effects of gas in the dust atmosphere.5/ Later, the emphasis shafted to evaluation of the relative fleet flammability and the ignition temperatures of coal dusts.6/ Much worthwhile effort was devoted to the development of Laboratory apparatus and test procedures that gave good correlation with large-scale explosion tests in the Experimental cost mine. In recent years a number of special problems were studied, mostly with bituminous Pittsburgh coal dust]

Jan 1, 1954

By Gregory Molinda

Historically, coal miners have known that roof shales can deteriorate in contact with humid mine air, causing massive roof falls and injuries from falling rock. It is critical to recognize rocks prone to weathering and to adequately support these rocks in order to ensure the long-term stability of the openings. In a recent study, NIOSH has used a wet/dry cycling test to determine the moisture sensitivity of over 800 specimens of roof rock from 25 U.S. coal mines. Fireclays and some gray shales are the most moisture-sensitive. Rocks with disturbed bedding, in contrast to flat-bedded rocks, are also more sensitive to water. Black shales are relatively un-reactive to moisture and serve to protect more reactive gray shales above. Mines that have roof rocks with moisture-sensitivity indexes above 40% can experience slaking roof conditions, and many require high coverage surface controls. Three case studies are presented in which the moisture-sensitivity index is correlated to roof conditions underground, and can be used to indicate long term deterioration. Engineering measures are described to control moisture-sensitive roof. In one case, roof screen not only reduces injuries from rock fall but also is shown to reduce roof falls. Keywords: coal mining, roof control, slaking, roof support, rock falls

Jan 1, 2008

By E. P. Youngman

In the Unfederated Malay States, with the exception of Johore, the rights of suzerainty, protection, and administration were transferred by giam to the British Government in 1909. In the States of Kelantan, Trengganu, Kedah, and Perlis, the rulers are assisted by State Councils and by British advisers appointed by the British Government.3 With respect to Johore, the largest, richest, and most highly organized of the Malay States not in the Federation, the treaty of December 11, 1885, with Great Britain, defined the relations of the State to the British Govern- ment and allowed the Maharaja to assume the title of "Sultan"; an amendment to this treaty (May 12, 1914) provided that the Sultan should be advised by a British officer, the General Adviser. ...... The political organization of the States is reflected in the mining legis- lation, Johore being the only one having a comprehensive code. The mining enactments now in force, according to the High Commissioner for the Malay States, are as follows:

Jun 1, 1932

By William C. Hood

A leaching column technique that produces effluent similar in quality to coal mine drainage in the Eastern Interior Basin has been developed. The columns are charged with 1000 grams of crushed overburden and cycled through the leaching process once a week for twelve weeks. Inter-relationships among the important chemical constituents are very similar to those present in actual mine drainage waters, but the overall concentrations of ion are more dilute in the leachates. Multiplying the leachate concentrations by a factor of 4.5 gives values similar to mine waters. Available data suggests that each of the leaching cycles represents about three years of natural weathering, so that the leaching technique can predict the evolution of the mire drainage water over a time span of nearly 40 years. Use of the leaching technique with drill core samples should provide a method of approximating mine drainage quality in advance of mining and should be quite useful in identifying potentially toxic units in the overburden. However, the results should he considered to be a 'worst case' situation because the technique' does not consider the effects of reclamation.

Jan 1, 1984

Electrical trailing cables are frequently damaged in usage, especially on continuous minors, and because of their weight and damaged condition present a safety hazard to personnel required to handle them. The U.S. Bureau of Mines and FMC Corporation signed Contract No. HO 122011 in August 1971. One of the contract tasks was to study the feasibility of techniques to improve trailing cable support and handling of power cables on underground coal mine machinery and to design a cable-handling device for a continuous mining machine. This report presents the results of the feasibility study, describes the design for a proposed cable handling device and concludes with a recommendation for future action to construct a test rig to evaluate the cable reel system.

Jan 1, 1972

By M. K. McCarter

Previous investigations suggest the possibility of determining shear strength of geologic materials by measuring the force necessary to rupture the web between two closely-spaced, parallel holes using a borehole jack. Current research using finite element modeling and laboratory testing of intact rock indicates that web failure initiates by tensile fracturing induced by a complex stress field. Based on these results, a theoretical justification for relating web strength with shear strength appears unlikely for holes of equal diameter spaced two diameters apart. Empirical results, however, show a strong correlation between average web strength and average unconfined compressive strength for some rock materials under laboratory conditions. A good correlation also exists between residual web strength and the residual angle of friction under the same conditions. This research project involves the construction and field testing of a large borehole jack. The jack is designed to operate within a conventional 12-1/4 inch rotary blasthole common to open pit mining. The system is capable of exerting approximately 800,000 pounds on curved platen measuring roughly 4x24 inches. Field tests indicate that the system will operate in a mining environment, and preliminary results suggest the possibility of using the force-displacement data generated by the jack to rank the competency of material within a mine bench.

Jan 1, 1982

By W. C. Babcock

This report covers Phase V of .a continuing program to apply a new liquid membrane process called coupled transport to the recovery pf metals from hydrometallurgical leach solutions. During this phase of the program, a membrane system of moderate scale was constructed and field-tested at the Exxon Highlands Mine and Mill Co. site near Douglas, Wyoming. The test unit contained four hollow-fiber membrane modules, each with 100 ft2 of membrane area. In the field tests, about 1000 gallons per day of leach solution was processed. The unit was operated on the leach solution for about 50 days. Leach solution entering the unit contained 100 ppm uranium. This concentration was reduced to about 5 ppm by coupled-transport treatment, and the uranium was concentrated to about 2 wt% as a uranyl carbonate product. Under these conditions, a transmembrane uranium flux of about 2.5 lb/ft2-year was obtained. An economic analysis showed that the cost of recovering uranium from this leach solution via coupled trans-port is about $1.20/lb. At higher concentrations of uranium in the leach solution this cost is reduced. For example, at 1000 ppm the cost of uranium recovery is about $0.30/lb.

Jan 1, 1983

By J. J. Forbes

The activities of the Bureau of Mines include the development and testing of self-contained oxygen breathing apparatus and other devices for respiratory protection, the development and tasting of devices for detecting dangerous or noxious mine atmospheres, and the training of men in the mineral industries in the use and care of this equipment to enable them to render effective service in mine rescue and recovery operations following mine fires and explosions, or under other conditions where irrespirable gases may be found in mines or mining plants. The first use of self-contained oxygen breathing apparatus for com- bating mine fires and explosions in the United States dates back about 30 years. Previous to that time, exploration for any distance ahead of fresh air was virtually impossible without great risk to life; moreover, the men called upon to render service at mine disasters were not well-versed in the properties and physiological effects of gases likely to be encountered. It was also impossible to work ahead of fresh air to restore ventilation, and if many stoppings were blown out by an explosion, air had to be introduced into whole areas or sections at once without knowledge of the conditions ahead; moving an explosive mixture of methane and air over live fire had to

Jan 1, 1938

By Richard V. Ageton, Harry E. Tufft, E. A. Holbrook

When an underground excavation is made, the rock surrounding the sides and top of the opening is deprived of its natural support and tends to fall. Whenever caving takes place, the time and extent of the caving depend on the character and condition of the rock. In strong homogenous rock, such as solid granite, even a large chamber may stand indefinitely, whereas a soft material, such as clay or a loose material like unconsolidated sand, falls immediately if not supported. Weaknesses in the rocks induced by structural features, such as joints, :fissures, bedding and cleavage planes, and fractures produced by blasting, will cause the falling of insecure blocks or slabs unless means are provided to support these in place. In an unsupported mine opening, as a tunnel, the first slight settling or adjusting movement of the rocks (the "initial creep" or "set") is caused by the great weight of overlying material pressing down the rock masses above and around the roof and sides of the opening until they key together in roughly the form of an arch. The rock, after it has adjusted itself to this shape, becomes. selfsupporting. Timbering is necessa.ry in all mining only to support, therefore, those comparatively small blocks or pieces of rock which tend to loosen from the top and sides of the opening during or after the formation 'of the natural rock arch, and which lie between this natural rock arch and the opening. This statement, of course, has its limitations. For example; a layer of strong rock, like limestone, may act as a beam; then only the material under the limestone will need support. Timbering is not, as is commonly supposed by the layman, used to supp!ort the huge mass of rock between the back (roof) of an underground opening and the surface. It would be impossible to place enough timbers in a:ny underground opening to support such a mass. This fact is not'·perceived by all miners.

Jan 1, 1923

1.0 Control House (DWG. NO. 56-401-G) - 1.1 Physical Description The Control House is a single story, 2728 square foot building with an adjacent transformer yard. A four foot overhang provides shade protection for the walls. The building is heated and air conditioned. The HVAC System has an elevated outside air intake and provides a positive pressure environment within the structure in order to prevent the infiltration of heavier-than-air, noxious gases. The materials of construction are as follows: Structure : Light-Gage Metal Framing Exterior Walls :Outside - Preformed, Metal Siding :Inside - Insulated Metal Liner Panels Interior Partitions :Gypsum Board over Light-Gage Metal Framing Roof :Insulated, Preformed Metal Panels Ceilings :Mechanical & Electrical Rooms - Exposed underside of Roof Panels Control Room, Lunch Room, Toilets, Entry - Suspended Acoustical Lay-In Tile Floors :Mechanical & Electrical Rooms - Concrete Slab on Grade Control Room, Lunch Room, Toilets, Entry - Resilient Tile Exterior Doorsand Windows :Preformed Metal Panel Manufacturer's Standard Units

Jan 1, 1979

By James H. Aase

Shales from 10 locations in Michigan were sampled, tested, and evaluated to determine their suitability as raw materials for producing lightweight aggregate by rotary-kiln methods. Sampling procedures and the geology of the shale units tested are discussed. Preliminary testing in a muffle furnace preceded extensive testing in a l6-inch by 14-foot rotary-kiln. Rotary-kiln products from these shales ranged in weight from 35.5 to 61.2 pounds per cubic foot (pcf). Concrete test specimens made pith selected aggregates were evaluated to determine the qualities of the concrete. Compressive strengths of the concrete ranged from 2,830 to 4,240 psi after 28 days of curing. Unit weight of the concrete ranged from 94.8 to 101.5 pcf. Lightweight aggregate suitable for use in structural concrete meeting ASTM standards was produced by the rotary-kiln method using shale samples from two locations.

Jan 1, 1967

By Sidney Katell

This report covers the period January 1962 through December 1962; it is a continuation of the series that began with the publication of Information Circular 7510 in October 1949. Also, it is the fourth in a series of reports prepared under a cooperative agreement between the Bureau of Mines and the American Association of Cost Engineers. The agreement provides for the publication of an annual cost bibliography with the work load evolved in the preparation shared equally. The abstracted articles, concerned with all facets of cost engineering in the field of chemical and petroleum plants and related subjects, are from tile following sources: 1. American Association of Cost Engineers Bulletin. 2. Bureau of Mines Information Circulars. 3. Bureau of Mines Reports of Investigations. 4. Chemical Engineering. 5. Chemical Engineering Progress. 6. Chemical Week. 7. Coal Age. 8. Coal Utilization. 9. Cost Engineering. 10. Hydrocarbon Processing and Petroleum Refiner. 11. Industrial and Engineering Chemistry. 12. Nucleonics. 13. Oil and Gas Journal. 14. Petroleum Management. 15. World Oil.

Jan 1, 1963

By Z. Zborovszky

The feasibility of using the nucleation properties of combustion generated particulates for the identification of their sources was investigated, using the Cloud Condensation Nuclei (CCN) Spectrometer. The Investigated materials included coal, wood, belt materials, electrical insulation, brattice cloth, and diesel exhaust. The materials were heated In an oven using filtered air flow, and their time, temperature, and the critical supersaturation spectrum of condensation nuclei (also referred to as the CCN spectrum) produced by the combusting material were recorded. Some data was obtained on a typical metal-mine background containing blasting products. The data was processed and analyzed In an attempt to specify parameters and limits that would allow the identification of the combustion sources. It appears that under controlled test conditions It Is possible to Identify the source on the basis of data derived from the CCN spectrum. More general use of the Idea for fire detection under uncontrolled practical circumstances in an actual mining environment does have potential but would require further research.

Jan 1, 1978

By Raymond G. Travis

This report describes coal-mining methods, power requirements, coal production and distribution, and coal resources of the Bull Mountain coal field in Musselshell and Yellowstone Counties, south-central Montana Investigations in the field, were conducted by Bureau of Mines engineers The report contains a short summary of the geology and geography of the field and discusses the following information secured during the field study: Method of mining practiced at each mine, including a description of each phase of the mining cycle. Coal produced and its distribution at each mine. Power requirements and the consumption of electricity per ton of coal produced by mines. Number of non employed by mines, and the production per man per shift underground and the over-all production per man employed. Estimates of future production and power requirements for the field as a whole. This information should be of benefit to any company or individual planning the development of now coal mines in the area or the expansion of present operations.

Jan 1, 1950

By Paul E. Loustaunau

This report describes a project in which three structured underground coal mine equipment operator training programs were developed. The project was carried out in two parts. In the first part, a research study was conducted to determine how on-the-job training is currently conducted in industry, and to determine the overall effectiveness of current on-the-job training. In addition, the possible application of the principles of social learning theory to on-the-job training was investigated. In the second part three prototypes on-the-job training programs were developed for shuttle car operation, roof bolter operation, and continuous miner operation. These programs were carefully structured to eliminate the shortcomings of current industrial on-the-job training identified in the research study and incorporated the application of relevant principles of social learning theory. The programs are prototypes which underground coal mine training personnel can use as models to develop their own customized equipment operator training programs.

Jan 1, 1983

By Harold M. Smith

This report presents a complete qualitative picture of knowledge of the composition of petroleum as of April 1965. The material is presented in detail on two imaginative maps--one, the Hydrocarbon Hemisphere, depicts the hydrocarbons that have been identified in petroleum; the other, the Heterogeneous Hemisphere, shows the sulfur, nitrogen, and oxygen compounds that have been found. All compounds are placed on the maps according to boiling point. The accompanying text illustrates by structural formulas the several types of hydrocarbon and nonhydrocarbon compounds identified, presents some quantitative data, and points out the possible geochemical significance of a number of the compounds. The possibilities of the Petroleum World of the future are discussed as a function of needed research,

Jan 1, 1966

By Harold M. Smith

This report presents a complete qualitative picture of knowledge of the composition of petroleum as of April 1965. The material is presented in detail on two imaginative maps--one, the Hydrocarbon Hemisphere, depicts the hydrocarbons that have been identified in petroleum; the other, the Heterogeneous Hemisphere, shows the sulfur, nitrogen, and oxygen compounds that have been found. All compounds are placed on the maps according to boiling point. The accompanying text illustrates by structural formulas the several types of hydrocarbon and nonhydrocarbon compounds identified, presents some quantitative data, and points out the possible geochemical significance of a number of the compounds. The possibilities of the Petroleum World of the future are discussed as a function of needed research,

Jan 1, 1966

By W. L. Falke

The Bureau of Mines has developed a system that permits the "soft" soldering of aluminum and aluminum alloys with standard tin-lead solders. The method employs application of a thin nickel-copper-alloy coating to the substrate, which enables the tin-lead solders to wet readily and spread over the areas to be joined. With conventional technology, aluminum and aluminum alloys are extremely difficult to solder because tenacious surface oxide films prevent wetting. With the Bureau-developed method, the aluminum substrate is mechanically or chemically cleaned to facilitate bonding to a minute layer of zinc that is subsequently applied with an electroless zincate solution. The nickel-copper-alloy (30 to 70 pct Ni) coating is then applied electrolytically over the zinc, using immersion cell or brush-coating techniques. Development of acetate electrolytes has permitted deposition of the proper alloy coatings. The coated areas can then be readily joined with conventional tin-lead solders and fluxes. The joints so formed are ductile, strong, and relatively corrosion resistant, and exhibit strengths equivalent to those formed on copper and brass when the same solders and fluxes are used. The method has also been employed to soft-solder magnesium alloys.

Jan 1, 1983

This report describes the work performed by Mine Research Company in developing a prototype mobile roof shield during 1971-1972 for the U. S. Bureau of Mines, along with background information leading to the design decisions adopted for the project. In addition, the report evaluates the choice of design and analysis and the results of the project in terms of future possibilities of mobile roof support systems. The report begins with the discussion of the problems of designing, building, and using mechanical and hydraulic roof support in coal mines. It then gives a historical summary of past work with discussions of the design choices made for previous roof support systems.

Jan 1, 1973