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By Roy C. Bartholomae

This Bureau of Mines report presents the results of a laboratory investigation of coal cutting mechanics and noise. These experiments were performed using linear cutting apparatus that operates over a broad cutting speed range. The influence of several coal cutting parameters on the noise, force, productivity, and specific energy associated with linear cuts was ascertained. Some basic theoretical aspects of coal cutting mechanics and noise generation are discussed, and the results of the laboratory experiments are used to formulate analytical models of the coal cutting forces and noise. The analytical model for coal cutting noise is then generalized to account for the more important effects of rotary cutting. Based on the generalized model, an estimate of the sound pressure level at an operator's position is made for a typical continuous mining machine. It is concluded that by employing linear rather than rotary cuts, using deeper depths of cut, slower cutting speeds, and more efficient cutting tools, it is possible to reduce the level of coal cutting noise, as well as provide benefits to other important areas of health and safety in underground mining.

Jan 1, 1983

By David L. Bickel

The following instructions and descriptions are presented in two parts to assist an individual to make the borehole deformation gage transducer, and to assemble and test the three-component borehole deformation gage. This Bureau 8 of Mines three-component borehole deformation gage (4, 8, 11)2 fits in a 1-1/2-in-diameter borehole that is drilled in rock and then overcored to determine rock stress.

Jan 1, 1978

By Thornton L. Neathery

Geologic investigation of a mineralized zone in eastern Alabama indicates that large quantities of talc and soapstone are scattered over a wide area close to the surface. Laboratory experiments show that this material may be upgraded to a high-quality talc. A market survey indicates that the talc deposits may be of current and long-range interest. The anthophyllite asbestos which is associated with the talc does not appear to occur in sufficient quantities to be considered as a primary commercial source.

Jan 1, 1967

By E. R. Maize

[In %-port of Invcstiptionn 7452 ,g dcniing with roof ~wet,ent in the Cmcibla r~ine, rof&apos;erence .,as m.da to the f~ct tiwt timker decny war, bsing studied at tho tine of writing. Thic napor, written a3er completion of that ~tudy, describ~s t1l.e ~mrl&apos;: and sunlharizea the fiats obtained. Ifhen tlle stu* oi roof novement bras be,- at Cxcible tw igeas \%.ere a6-r;incsd. on decay of tiriber Q: scne of :he olficialr;: (I.) 9:la.t timber decay v:as unustmlly rapid in ,tho Ciuoiblc mins, ,m?. ((2) that timber coated with rock ri..~st deixiyad morrl mpirlly thnn those %hat vsrc not so coated. Thsx ::ore no records by which tkeso &apos;iaeas could &apos;L;e tertcc?, ard it cnpsarefi vise to make a limite6 in- vo3tiption, p~.rticu!.ai.ly of +.he effect of roc!< dusting on decny, as rock ductirg is nn importnnt mer-ns of ~rc-,rcnt?;~g cad-dust eql-osions. ]

Jan 1, 1941

By Lulie H. Crump

Salient information on reserves, production, and consumption of fuels and energy by State is summarized in this Bureau of Mines publication. Reserve and production data are shown for each of the fossil fuels (coal, crude oil, natural gas liquids, and natural gas) and for uranium. The consumption data of each of the major consuming sectors (household-commercial, industrial, transportation, electric power, and miscellaneous) are broken down by energy source (coal, petroleum, natural gas, hydropower, and nuclear). In addition, total energy consumption in the Nation in 1973 is compared with consumption in 1972 and 1974 (preliminary data).

Jan 1, 1976

By Stanley K. Haines

This Bureau of Mines publication comprises 19 tables of data concerning domestic barite production and consumption, imports, and world production for the years 1880 to 1976. Barite is vital to the petroleum industry, with 90 percent of domestic consumption used in drilling muds. Domestic production has traditionally fallen short of consumption: in 1976, 41 percent of the 2.2 million tons consumed was imported. World production of barite increased from 269,000 tons in 1923 to 5.2 million tons in 1975 but is in danger of falling short of future demand. The compiled data provide a comprehensive base of information.

Jan 1, 1978

By Bill Linville

During calendar year 1972, the Bureau of Mines was engaged in some 20 major areas of research for the development of new and improved efficient methods of conservation and utilization for petroleum and natural gas, oil shale, and coal. Made up of numerous projects described in this report, the program was carried out through research performed at research centers and laboratories in the field supervised and supported by administrative personnel of this Bureau of the Department of the Interior. Based un this research, 186 technical reports were published by the Bureau or others, and numerous other reports were prepared for Federal agencies, State agencies, and organizations engaged in cooperative research programs with the Bureau.

Jan 1, 1973

By J. M. Kuchta

Bench-scale test methods were developed by the Bureau of Mines for use by the Department of Transportation in the classification of solid and liquid oxidizers. A burning rate test is recommended for evaluating the fire hazard of solid inorganic oxidizers when mixed with a red oak sawdust as the reference combustible. A spontaneous ignition test is proposed for evaluating liquid and solid inorganic oxidizers which may decompose violently or ignite spontaneously when unmixed or mixed with the wood sawdust under unconfined conditions. Test results are compared for various representative oxidizers and a classification system is proposed for use in the government transportation regulations.

Jan 1, 1972

By Kevin M. Connor, O&apos

This report documents-the process of literature review, site selection, instrument installation, data acquisition, and preliminary data reduction performed to evaluate the influence of rock mass discontinuities on coal mine subsidence. A system of surface, subsurface and mine level instrumentation was installed at the Armco No. 7 Mine in Montcoal, West Virginia where the overburden varied in thickness from 630 to 1040 feet. Survey monuments, borehole pressure cells, full profile borehole inclinometer-extensometers, mine level extensometers, stressmeters and tape extensometer convergence stations were installed to monitor displacements and stress changes. Final design of the instrumentation system was based on: a) review of available information, b) field mapping and analysis of areal photography, c) drilling, and d) borehole geophysics. The report contains the complete graphed data of stress and displacements accompanying the longwall mining of a 4800 ft long by 480 ft wide coal panel.

Jan 1, 1983

By Mark L. Chatman

This report presents an economic mineral assessment and Inventory of mines and prospects In the approximately 176,000-acre Patagonia Mountains-Canelo Hills Unit of Coronado National Forest. Deposits or areas most likely to experience future development are characterized in terms of their economics, based on data acquired by the author from a variety of sources, and supplemented by USBM field data collected by other workers in 1990 and 1991. Numerous mine maps, rock-chip sample assays, and detailed descriptions of mine and prospect sites are in this report and appendixes. Heavy but sporadic mining, mainly between the 1850&apos;s and 1950&apos;s was nearly all confined to the Patagonia Mountains. High-grade sulfide veins, replacements, and skarn deposits accounted for most of the production, which included large quantities of zinc, lead, copper, and silver, and considerable quantities of gold. Small Quantities of molybdenum, manganese, tungsten, and placer gold have been mined. Most of the traditionally mined metalliferous sites will not see future activity due to the low tonnages present and removal of most high-grade rock. Possible future development areas include copper porphyries and breccia pipes; most are too deeply buried for current development. Localities where similar deposits may be concealed are identified.

Jan 1, 1994

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Jan 1, 1975

By W. P. Yant, G. W. Jones

"Introduction.During the past two years the Bureau of Mines has conducted a study of natural-gas heaters*** to determine (1) what types of heaters literate carbon monoxide; (2) why carton monocide is liberated; and (3) how, by change of design or construction, the liberation of this gas can be largely eliminated, In addition to the above study the bureau has investigated cases in the Pittsburgh dis¬trict where fatalities have resulted from carbon monoxide given off by natural-gas heaters.Since these fatalities were first brought to the attention of this bureau through the press, it is likely that some cases were missed and thus not listed. On the other hand, some cases reported as being due to carbon monoxide poisoning, on investigation were found to be due to causes other than carbon monoride.The cases listed herein were shown in all probability to be due to carbon monoxide. Those in which there is any doubt have been omitted; so have those in which there was part asphyxiation, where the victims later recovered."

Feb 1, 1924

By John J. Sammarco

The U.S. Bureau of Mines has developed a regulated, intrinsically safe, rechargeable power supply for portable electronic equipment for underground use. The regulated output is ideal for microprocessor power requirements and is suited for operation in hazardous environments. Two rechargeable, sealed batteries are contained within the power supply. Provisions are made to use an external source of power if these batteries fail. Provisions are also made to charge these internal batteries when needed. The circuit is composed of three main circuits: the main regulator circuit, the input protection circuit, and the output protection circuit. The main regulator circuit provides remote voltage sensing, current sensing, fault monitoring, and internal thermal protection. The input protection circuit checks for excessive input current and low battery conditions. The output protection circuit contains two overvoltage detection devices. Schematics, a parts list, and a calibration procedure are provided in this report to enable readers to fabricate the power supply.

Jan 1, 1989

By N. A. Pace

This is one of a series of papers being published by the Federal Bureau of Mines for the dissemination of information on methods and practices used in the mining and preparation of crushed stone for market requirements. Performance in terms of units of work or tons produced per machine and per operator man-hour are given whenever that information is available. Direct operating costs are useful for comparing different methods, and are, therefore, included if possible. In addition to the factual description of equipment and methods used, it is desirable to discuss the engineering reasons for the choices that have been made. This paper is particularly concerned with the opertions at the Columbia plant of Palmetto Quarries Co. of Columbia, S.C. The plant is about one-half mile east of the Congaree River and adjacent to the southwest corner of the city of Columbia. Rail access is by the Atlantic Coast Line Railroad, and by a spur strack of the Seaboard Airline Railroad.

Jan 1, 1962

By B. W. Gandrud

The upper part of the Alabama deposits of crystalline graphite consists of an oxidized ore derived from, the underlying unoxidized ore through prolonged weathering. The degree of oxidation in different sections and at different depths within the bed is nut. uniform. The original ore is hard and blue-gray; the weathered product is soft and brown and is the only part that has been mined to any extent. Samples of both oxidized and unoxidized ores were obtained from two of the large graphite deposits of Clay County. Three additional samples of oxidized ore were obtained from different portions of a third property in the same region. In this report, ores 1 to 5 are of oxidized material and ores 6 and 7 of unoxidized.

Jan 1, 1934

By Tuncel M. Yegulalp

The objective of this study was to categorize mining operations in the stone, and sand and gravel industries into areas of similar ground control functions and define initial factors affecting operational safety in each area, by means of utilizing publicly available data, telephone interviews and on site observations. The findings and recommendations presented in this report are based on the information collected during the two phases of the project. They also contain, in part, the collective qualitative opinion of the operators with respect to government rules and regulations on ground control safety and the implementation of these rules and regulations by government inspectors.

Jan 1, 1981

This Bureau of Mines publication contains five papers pertaining to the effective grounding of mine power systems, as follows: Ground-check monitor types and safety characteristics; ground wire monitors for surface coal mines; ground bed design and measurement; electrical ground rod corrosion; and a continuous ground bed resistance monitor.

Jan 1, 1979

By Wils L. Cooley

The report covers several aspects of mine safety ground systems, primarily for underground coal mines. The design of a combined ground fault-ground check monitoring system is presented. An analysis is made of grounding systems for dc shuttle cars. Complete resistance data and results of physical inspections of self-salting ground rods are presented. A detailed resistance and economic analysis is presented for the use of composite materials for building inexpensive and effective ground beds in high-resistivity areas. The desireability of penetrating the coal seam with a borehole safety ground is investigated. A report is made of a Mine Substation Grounding and Bonding Workshop.

Jan 1, 1980

By Kenneth Trelewicz

This report describes the total effort that went into developing environmental test criteria for general mine instrumentation. The project was a two-phase effort. Phase I consisted of research and mine visits to develop an environmental profile for mine instrumentation. The profile was translated into general requirements and then into test requirements. A review of existing government and commercial specifications was performed to determine if they matched mine instrumentation test requirements. Finally, a set of environmental test procedures was developed for the testing of mine instrumentation. Phase II consisted of selecting and purchasing sample mine instrumentation and subjecting them to the previously developed tests. The purpose was twofold: (1) to evaluate the criteria developed for use as an instrumentation test document and (2) to determine the effects of the various criteria on a representative sample of both proven and newly developed instrumentation. The test criteria were then modified, based on the results of the testing, and are listed therein.

Jan 1, 1981

By F. S. Karn

Conditions necessary to obtain optimum yield of useful products when coal is rapidly heated to extreme temperatures by laser irradiation were determined by the Bureau of Mines. Product distribution and yield were investigated as functions of several variables. Low-rank coals with high-volatile matter gave highest total gas yields. Medium-rank coals gave the highest yields of H2 and CA and low-rank coals gave highest yields of CO and C02. Macerals gave gases of approximately the same composition, but the total gas yield increased in the order fusinite, micrinite, vitrinite, and exinite. Total gas and C2H2 yields varied inversely with particle size. The addition of nominally inert gases such as Ar, He, N2 increased yields of H2, C2H2, and total gas. Metals such as nickel and platinum had little influence on the rate of coal decomposition. Total gas yield increased with total energy of irradiation, and the ratio of C2H2-CH4 increased with concentration of energy. A study was also made of the irradiation temperature, and a material balance was calculated.

Jan 1, 1970