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By J. W. Miller

An investigation was begun by the Bureau of Mines in 1948 to determine the preparation characteristics of American coals. Results of the investigation were planned to be reported on a county basis and from the data developed to determine: 1. Which coals either as mined or after beneficiation by conventional preparation are chemically suitable under present standards for producing metallurgical coke. 2. Which coals require special and more intensive treatment in preparation than is now practiced. 3. Which coals cannot be considered potential sources of metallurgical coke, regardless of preparation by present-day methods. This report is one in this county series that describes the preparation characteristics of the coals of Lee County, Va.

Jan 1, 1957

By Robert F. Chaiken, Thomas H. Dubaniewicz, Gregory M. Green, Kenneth L. Cashdollar

Optical technologies have progressed rapidly in the past 15 years. One application of laser technology in underground coal mines currently under evaluation is the remote measurement of explosive methane gas. Federal regulations require that atmospheric monitoring systems used in gassy underground mines where permissible equipment is required shall be intrinsically safe. Mine Safety and Health Administration criteria for the evaluation and testing of intrinsically safe apparatus and associated apparatus contain no specific guidance for optoelectronic components such as diode lasers. The National Institute for Occupational Safety and Health is conducting a study to help provide a scientific basis for developing appropriate safety guidelines for optical equipment in under- ground coal mines. Results of experiments involving ignition of methane-air mixtures by collections of small heated particles of Pittsburgh seam coal and black iron oxide are reported. The inert but more strongly absorbing iron oxide targets consistently ignited methane-air mixtures at lower powers than the coal targets. Minimum observed igniting powers for laser energy delivered by 200, 400 and 800 pm core fiber optic cables and directed onto iron oxide targets in methane-air atmospheres were 0.6, 1.1, and 2.2 W, respectively. Comparisons with the results of other researchers are made. A thermal layer theoretical approach to describing the process is included as an appendix.

In the three years to June 2005, 959 injuries associated with continuous miners (CMs), shuttle cars (SCs), load-haul-dump and personnel transport (PT) were reported by NSW underground coal mines, comprising 23% of all injuries reported. The present paper reports an analysis of the narrative field accompanying these reports to determine opportunities for controlling injury risks. The most common combinations of activity and mechanism were: strain while handling CM cable (96 injuries); caught between or struck by moving parts while bolting on a CM (86 injuries); strains while bolting on CM (54 injuries); and slipping off a CM during access, egress or other activity (60 injuries). For the other equipment considered, the common injury mechanism was the vehicle running over a pothole or other roadway abnormality causing the driver or passengers to be injured (169 injuries). Potential control measures include: monorails for CM services; hydraulic cable reefers; handrails on CM platforms; redesign of CM platforms and bolting rigs to reduce reach distances during drilling and bolting; improvements to guarding of bolting controls; standardisation and shape coding of bolting controls; two handed fast feed; improvements in underground roadway maintenance, vehicle suspension, visibility and seating; and pedestrian proximity warning devices.

By R. Larry Grayson

Barrett EA, Kowalski KM [1995]. Effective hazard recognition training using a latent-image, three-dimensional slide simulation exercise. Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9527. NTIS stock number: PB95-170379. Beus MJ, Orr TJ [1995]. Computer modeling and analysis of the Greens Creek Mine, Admiralty Island, AK. Spokane, WA: U.S. Department of the Interior, Bureau of Mines, RI9530. NTIS stock number: PB95-176418. [ ]

Determine the extent to which remote-sensing techniques, primarily lineament analysis, can be used to identify geologic structures that may affect the location and migration of subsidence over abandoned underground coal mines in the Colorado Springs, CO, area. Compile data using a geographic information system (GIS) to allow efficient and reproducible comparisons and analyses. Background The basis for evaluating abandoned mine land (AML) sites with remote-sensing techniques comes from past and ongoing Bureau ground control research using remote-sensing data to identify potential hazards caused by geologic structures (faults, joints, etc.) above active underground coal mines. Research showed that lineament (linear feature) analysis of Landsat Multispectral Scanner (MSS) images could indicate locations of fractures and fracture trends that had varying, but significant, impacts on the stability of mine openings. Such geologic structures should be identifiable over abandoned mines as well. If fractures are present, even if they arc not faults, they should represent areas of potential instability over these mines and, therefore, should tend to localize subsidence when it occurs, particularly for deep and moderately deep portions of mines.

Jan 1, 1992

By J. R. Thoenen

[Since the publication of the preliminary report on this subject in July, 1927, (The Wire Saw in Slate Quarrying, Preliminary Report, Serial No. 2820, by Oliver Bowles) the wire saw has been in constant daily operation at the quarry of the Colonial Slate Company. Luring this time between twenty end thirty successful cuts have been made varying in length from forty-five to ninety-two feet and in depth from six to ten feet. No accurate time records have been kept on these cuts but they have totaled over 12,000 sq. ft. of area and required 19,000 lineal fact During these cuts the average speed of cutting has risen from the 12.8 sq. ft. per hour obtained in the original recorded tests to between 15 and 20 sq. ft. per hour, with the present rate running very close to 20 sq. ft. per hour at this quarry.]

Jan 1, 1928

By Forrest T. Moyer

Injury experience in the mineral mining and processing industries during 1968 was slightly improved in the nonfatal-injury record but worse in the fatality record. The resulting frequency rate of all injuries was slightly better, whereas the injury-severity rate retrogressed appreciably from the figure for 1967. Overall operating activity, as measured by man-hours of worktime, was slightly higher in 1968. However, there were several major segments of the mineral industries in which activity was lower owing to reduced demand for mineral products and to several major work stoppages. These statistics comprise the injury and work experience of all personnel engaged in production, exploration, development, maintenance, repair, and force-account construction work, including supervisory and technical personnel, and working partners and owners at mineral-producing and mineral-processing establishments in the United States. Data concerning officeworkers are excluded except for the oil and gas industry for which such information is not separable. All injury rates and totals are calculated from data before rounding. The data for 1968 are preliminary except for the anthracite, coke, petroleum and natural gas, native asphalt, peat, and slag industries, which are final. The figures represent full coverage for all industries except oil and gas for which coverage is not complete, particularly with respect to small companies.

Jan 1, 1970

By Doris M. Hyde

Belize remained relatively insulated from the social and political turmoil that affected some of its Central American neighbors. This stability encouraged new foreign investments that assisted the economy, especially in tourism and agriculture. The mineral sector remained limited to construction-oriented materials. Oil exploration efforts continued by the various concessionaires.

Jan 1, 1987

Miners, like everyone else, must be able to see well in order to work well. But simply hauling bigger and brighter lights into the mines does not necessarily produce better mine illumination. This chapter tells why. Increasing the power of the light source can create problems of portability, glare, adaptation and contrast. This chapter also discusses some ways to increase illumination by Improving the reflectability of walls, roofs and other exposed surfaces. In Chapter IV you learned that the "brightness" of a room or work area was really a matter of how much light was reflected from the walls, roof, and other surfaces. Therefore, if you want to Improve visibility you should increase the amount of reflected illumination. O HOW DOES ONE DO THAT? One way of Increasing reflected illumination would be to increase the power of the light source.

Jan 1, 1976

Reduce injury to people or damage to equipment when a scheduled production blast is detonated. Approach The essential elements of an effective blast area security system were identified through case studies of five mining operations where the blast area guarding practices were considered to be superior to those generally found in the industry. These elements were used in making recommendations for improved blast area safeguarding practices. Background The blast area security system is a means by which the mine operator prevents injury to people or damage to equipment when blasting is performed. Analysis of blasting accidents showed that most blasting accidents occur during scheduled blasting and are due to inadequate blast-site security. Factors contributing to the system's breakdown are failure to clear the blast zone, inadequate guarding. and failure of personnel to follow instructions, retreat to a safe location, and/or take adequate cover. Mine personnel, visitors and even trespassers can inadvertently wander into a blasting zone unless proper procedures exist to ensure that all personnel are cleared from the blast zone and kept safely away until after blasting IS completed. Statistics show that the blaster is the miner most frequently injured In these accidents.

Jan 1, 1986

By Richard G. Geyer

One aspect of a program to improve the chances of survival following coal mine disasters is the development of a communications system which will allow surviving miners to make their circumstances known to rescue teams. Various communications techniques can be considered, including electromagnetic systems, acoustic systems, and hybrid systems. The electromagnetic and acoustic systems would be independent of existing mine communications systems and set up specifically for use in emergencies. Hybrid systems might use a short emergency link to existing telephone systems in the mine. Many variations are technically possible, and the primary task is in evaluating the relative merits of each, so that the most workable system can be selected.

Jan 1, 1973

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Jan 1, 2011

Reduce shaft sinking costs and workers exposure to mechanical hazards, drill dust, blast dangers, and fumes. Approach Replace drilling and blasting by using a large, cab-mounted impact breaker suspended from the bottom work deck of the galloway. How It Works The pneumatically actuated impact breaker is positioned by an articulated boom con-trolled from an operators cab. The breaker delivers 2,000 ft-lb blows that fragment the rock at the shaft bottom. Mucking is accomplished by a backhoe bucket on an articulated boom mounted on the cab. See photograph. The mucked material can be removed either by dumping into a previously drilled borehole or by being lifted out in a muck bucket as shown in the drawing. Positioning of the breaker, rotating the cab around its vertical axis, and moving the cab support frame around the perimeter of the shaft are all controlled by one joystick. Separate controls position the mucker boom, which can be swung horizontally through a 180° degree arc towards either side of the cab. Because the cab can be rotated to any position around its vertical axis, and can also be moved in a horizontal circle around the shaft, virtually any position on the bottom of the shaft can be reached by the breaker and mucker.

Jan 1, 1981

By Robert P. Vinson, John C. LaScola, Fred N. Kissell, Edward D. Thimon

The face ventilation measurement method developed by the Bureau of Mines involves releasing a small volume of tracer gas (SF6) on the off-curtain side of the working face at the start of the mining cycle. At the same time, gas bottle samples are taken in the immediate return airway. The gas samples are analyzed, and a curve is drawn of SF6 concentration versus time. From this curve, the percentage of gas removed per time is calculated. A curve showing a high percentage of the tracer gas removed in a short period would represent a well-ventilated face. The face ventilation measurement method was tested in a full-scale mine entry model. Subsequently it was used underground to evaluate the spray-fan ventilation system and in an MSHA test facility to test machine-mounted scrubbers. The method was shown to be a simple and effective way of evaluating face ventilation systems.

Jan 1, 1980

Permit visual inspection of underground cavities dam the surface. Approach A closed circuit TV camera and a 35mm still camera are lowered down a borehole, and remotely operated. How It Works A platform holding the cameras, and other equipment is lowered on a graduated cable until the depth of interest is reached. Then a quartz lamp and the TV camera are turned on. The television picture is monitored at the surface and recorded on video tape. Areas of special interest are photographed with a 35mm still camera. These photographs contain more detail than TV images because photographic film is capable of higher resolution than a TV transmission.

Jan 1, 1979

By F. E. Armstrong

The Bureau of Mines has conducted a research program to systematize the art of locating uncharted and lost oil and gas wells that penetrate coal seams; this publication presents a preliminary summary of its findings. Although no method or combination of methods will guarantee finding all uncharted and abandoned wells in a particular area, at least 75 percent of such wells can be located by compiling and applying all available information and using modern metal detectors.

Jan 1, 1973

By R. V. Ramani, V. T. Burgos, J. A. McClay

The systems contributing to the cost analysis, and the flow of data input and output related to these systems, are brought into focus in Figure 6. The various sub-systems of the Master Design Simulator provide the raw operating data basic to the cost model which, operating independently, accumulates the raw input, assigns costs to this data by standard or modified costing procedures, manipulates the costs into standard formats and outputs the data for managerial evaluation. Cost Modeling Direct costing methods are not complex in the sense that elemen¬tary arithmetic is employed using the same basic relations for each cost category. The basic cost model relations described above are illustrated in Figure 7. The greatest difficulty encountered in the transition from a dy¬namic systems simulation model to a costing model is the time frame of the input and output data. Dynamic simulation models utilize a small time increment, on the order of seconds or fractions of seconds, to analyze system operations and interactions. On the other hand, for cost computation and reporting, the smallest relevant time unit is the shift, with reporting periods expanding to days, weeks, months, and years. Complications arise in the accumulation of data for the various report periods due to the use of the Gregorian calendar by modern so¬ciety. The potential for simulation for the life of the mine, possibly in excess of 50 years, increases the complexity of the costing process

Jan 1, 1975

Lower the respirable dust exposure of longwall shearer operators by keeping the dust cloud confined to the face. Approach Change the location of face-side machine cooling, water sprays. How It Works The dust breathed by the longwall shearer operator is usually produced by the shearer itself. The dust cloud originates at the face, and the exposure of the operator depends largely on how quickly this cloud spreads into the walkway. Water sprays on the shearer body can have a large effect on dust cloud spreading. Results to date indicate that sprays can help confine the dust cloud to the face if they are carefully placed. Otherwise they can make dust levels far worse. The worst offenders are often face-side sprays used to discharge cooling water from the cooling jackets of the shearer motors. These face-side sprays set up an air circulation pattern as illustrated in the drawing. Air induced by the sprays to flow towards the face, raises the air pressure in front of the face, which causes the air flow to turn and then move back over the shearer, bringing dust with it into the walkway.

Jan 1, 1981

Develop new technology to encourage domestic processing of automobile catalytic converters for recovering platinum -group metals. Background Automobile catalytic converters are used to convert pollutants in automobile exhaust into water vapor, carbon dioxide, and nitrogen, About 1 million troy ounces of platinum-group metals arc used each year in the. United Slates to manufacture catalytic converters. It has been estimated that about 60 pct of the used catalytic converters arc being collected. Most of these used catalytic converters were not processed in the United States but were exported to Japan or Europe for processing. In 1991, about 250,000 troy ounces of platinum-group metals were recovered from scrap catalytic converters collected in the United States. Each short ton of decanned catalyst may contain 30 troy ounces of platinum-group metals valued at over $15,000. Development of an economic process for the recovery of platinum-group metals that can be operated on a small or large scale may increase, the percentage of catalytic converters collected and encourage domestic processing to recover a platinum-group metal concentrate. This would significantly decrease the dependence of the United States on imports for these critical and strategic metals.

Jan 1, 1992

By M. A. Elliott, H. H. Schrenk, L. B. Berger, John C. Holtz

"INTRODUCTION Among the hazards that may attend the use of Diesel engines in mines, tunnels, or other underground operations the presence of harmful or objectionable constituents in the exhaust gas must receive due consideration to prevent the formation of unsafe or unhealthful working environments in these places. Previous reports of this series have presented discussions of the composition of exhaust gas from engines in proper mechanical condition, 6/ the effect of adding some of the exhaust gas to the intake air of the engine, 7/ the effect of operation in atmospheres containing natural gas, 8/ and the effect on exhaust-gas composition of conditions that influence the characteristics of fuel injection in Diesel engines. In all these studies the properties of the fuels used were in general conformity with specifications usually recommended by the manufacturers of Diesel engines. In evaluating the physiological significance of the various components of the exhaust in these experiments, the toxic or objectionable gases determined were carbon monoxide, carbon dioxide, oxides of nitrogen, and aldehydes. Because of the low sulfur content of' these fuels, compounds such as sulfur dioxide and sulfur trioxide were not determined, although in discussion of the test results attention was directed to the fact that if fuels of higher sulfur content were used, the concentration of such compounds in the exhaust would become a significant factor in establishing the quantity of ventilating air required to furnish satisfactory dilut1on of the exhaust gas in underground working places."

Jun 1, 1943