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Objective Develop field measurement and computer modeling methods to predict the potential for hang-ups and structural failures in underground mine ore paws. Background Analysis of Mine Safety and Health Administration (MSHA) accident statistics has identified ore pass hazards as a significant safety problem in underground metal mines in the United Stales. Recent ore pass failures have underlined the lack or ore pass design methods ant1 standards available to both MSHA and mine engineers. Injury and fatality data for the 20-ycar period between 1975 and 1095 show that nearly 75% of the injuries were directly or indirectly related to pulling or freeing ore pass chutes, the use of hand tools, falls or broken rock, and structural failures or chutes or gates and ore pass walls.

Feb 1, 1998

By Harold W. Lipper

Helium production and shipment reached new peaks in 1.361. The Bureau of Mines produced 727 million cubic feet, 13 percent more than the 1960 record, and shipped 552 million cubic feet, 16 percent more than the 1960 record. Production exceeded demand for the third successive year, enabling the Bureau of Mines to add 174 million cubic feet to the volume stored underground for future use. At the end of 1961, the total volume of helium in underground storage in the Clifside gasfield was 44-7 million cubic feet. Contracts to implement a long-range helium conservation program were completed with four companies, obligating all the contracting authority of $47.5 million a year made available by the Congress. The four companies will finance, build, and operate helium extraction plants to recover from natural gas an annual average of 3.1 billion cubic feet of helium that would ordinarily be wasted when the helium-bearing natural gas is used for fuel.

Jan 1, 1962

By Robert A. Bruce

A motion transducer based on coherent mixing of laser light backscattered from rough surfaces is evaluated in terms of sensitivity, bandwidth and range. Tests made with a prototype composed of a 4-mw HeNe laser, a silicon avalanche photodiode, and a 15-cm aperture telescope demonstrate that remote measurements with reasonable bandwidth and accuracy are feasible at distances up to 100 meters.

Jan 1, 1977

By Roy L. Wilfong

Surface area measurements were conducted on cadmium sulfide powders following thermal treatments at temperatures up to 500° C and treatment times up to 1 week. Thermal treatments at temperatures up to 300° C produced no significant changes in the surface area of the powders even after 1 week of exposure. At 500° C some decomposition of the cadmium sulfide occurred.

Jan 1, 1970

By C. A. Komar

Hardness, tensile strength, and impact toughness of dry and brine-saturated sandstone specimens were measured at ambient, cryogenic, and elevated temperatures as a measure of the relative stability of reservoir rocks for subsurface disposal of liquid wastes. Hardness measurements were inconclusive. Tensile strength and impact toughness were significantly higher at -320° F than at ambient temperature, but were relatively unaffected at 700° F. Impact toughness was reduced by subjecting the specimens to three cycles of rapid temperature changes (thermal shock) over a 1,000° F range. Tensile strength of brine-saturated sandstone was less than that of dry sandstone. Based on results of the tests, reservoir sandstone likely would be stable if exposed to extreme temperatures of liquid wastes, although rapid changes in waste temperatures should be avoided.

Jan 1, 1971

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.

By Mark Larson, Doug Tesarik, Joe Shoemaker, Brad Seymour

In cooperation with Cyprus Twentymile Coal Co., researchers from the National Institute for Occupational Safety and Health (NIOSH), Spokane Research Laboratory, conducted a study at the Foidel Creek Mine, an underground coal mine near Oak Creek, CO, to evaluate the stability of underground working conditions as a longwall advanced through a series of backfilled cross-panel entries. Instruments installed in the cross-panel entry pillars, backfill, longwall panel, and adjacent headgate entry were continuously monitored by a computerized data acquisition system as the longwall approached and advanced through the backfilled section of the panel. Data collected from these instruments were analyzed to determine the magnitude and direction of the secondary principal stress changes ahead of the longwall face, deformation and closure of the headgate entry, and stability of the cross-panel entry pillars and backfill. A three-dimensional, boundary element model was calibrated to accurately predict mining-induced stress changes and the distance they occurred ahead of the longwall face. As the longwall advanced through the backfilled entries, most of the mining-induced load was supported by the cross-panel entry pillars. The backfill provided stability for the roof and floor of the in-panel entries and also confined the entry pillars significantly improving their load-carrying capacity. Comprehensive information derived from backfill material property tests, instrument data, underground observations, and numeric modeling results document the safety and stability of the 8-Right mine through and should provide beneficial case study information for other longwall backfilling applications in the future.

By James C. Ault, Walter W. Kaufman

This Bureau of Mines manual for design of surface mine haulage roads covers such aspects of haulage road design as road alignment (both vertical and horizontal), construction materials, cross slope, and drainage provisions. Traffic control and design of proper lane widths to promote safe vehicle movement are included, as are suggested criteria for road and vehicle maintenance and for runaway vehicle safety provisions. The aim of this publication is to provide those involved with surface mine haulage road design with a complete manual of recommended practices that, if implemented, will promote safer, more efficient haulage routes.

By G. B. Atkinson

Properties of catalysts prepared from intermetallic compound precursors were investigated by the Bureau of Mines as part of its mission to decrease U.S. dependence on foreign sources for scarce catalytic materials, such as nickel, cobalt, and chromium. Methods were developed whereby catalysts with surface areas of 30 to 40 m2/g were prepared from intermetallic compounds. Activity of these catalysts for the methanation reaction and methanol synthesis was deter-mined using a fixed-bed, single-pass, flow-through reactor. Catalysts prepared from rare-earth-nickel intermetallics had specific activity for methanation that was five times greater than that of commercial catalysts and were equal to or better than commercial catalysts with regard to sulfur tolerance. Under identical reaction conditions, catalysts prepared from thorium-copper intermetallics produced more than 10 times as much methanol as a commercial low-pressure catalyst and exhibited a high degree of catalytic stability.

Jan 1, 1982

By Robert W. Freedman

This report describes sampling and analytical procedures used for measurement of sulfates in diesel tailpipes and in the diluted exhaust within dilution tunnels. A variety of methods exist for sulfate analysis for such systems, including ion exchange. Two chemical methods used by the Bureau of Mines are described in detail. These are based upon spectrophotometric measurement of chloranilic acid using barium chloranilate. The procedures are rapid and relatively inexpensive. In general, ion exchange is preferred by many analysts for sulfate analysis. However, it is more complex and expensive than chloranilic acid procedures, which are adequate for exhaust analysis.

Jan 1, 1982

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

1 14 THIS IS A DIGITAL COMPUTER SIMULATION OF THE VENTILATION SYSTEM OF A MINE LOCATED IN WASHINGTON COUNTY, PENNSYLVANIA. THE VENTILATION SURVEY ON WHICH THIS SIMULATION IS BASED WAS RUN FROM OCT. 27-30 AND ON NOV. 2, 1976 IN THE ACTIVE PORTION OF THE MINE INBY COMBS SHAFT AND THE INACTIVE PORTION AFOUND AND INBY DONAHOO SHAFT. FOLLOW-UP SURVEYS WERE THEN RUN ON FEB. 18 AND FROM MARCH 7-11, 1977 TO INCLUDE THE MAIN HAULAGE SYSTEM OUTBY THE ACTIVE AREAS OF THE MINE. ALL SURVEY DATA WAS NORMALIZED TO A STANDARD DENSITY OF 0.075 POUNDS/CU.FT. PRIOR TO THE CALCULATION OF INPUT PARAMETERS FOR THIS SIMULATION. IN THIS RUN, THE ORIGINAL VENTILATION NETWORK HAS BEEN MODIFIED TO INCLUDE NEW INTAKE AND RETURN AIRSHAFTS AT THE WEST MAINS. IN ADDITION A CONNECTION HAS BEEN MADE BETWEEN THE MINE UNDER STUDY AND A SHAFT IN A WORKED OUT MINE IN THE 1 FACE AREA. THIS SHAFT IS CONSIDERED AN INTAKE SHAFT FOR THIS RUN.

Jan 1, 1977

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 H. R. Shell

Variations between laboratories on the silica and alumina content of calcined kyanite led to this Bureau of Mines study of the extent and nature of the differences. In particular, Bureau scientists hoped the study would lead to correction of the causes of the dissimilarities. A sample of calcined Kenya kyanite was analyzed by seven different laboratories familiar with silicate analysis. The compiled data indicated differences originating from lack of recovery of silica after two acidic dehydrations, from high alumina caused by several factors, from loss or gain of iron during sample fusion, and from indifference regarding the accurate determination of minor constituents.

Jan 1, 1959

By Robert L. Chufo, H. Kenneth Sacks

Medium-frequency (MF) waves can propagate in a coal seam, bounded above and below by conducting rock, in an approximate transverse electro-magnetic (TEM) transmission-line mode with the electric field vertical and the magnetic field horizontal. The theory of this coal seam mode is applied to recent MF data for a number of mines in order to classify the propagation characteristic of the mines in a simple way. When conductors such as rails, trolleylines, or power cables are present in the vicinity of the measurement path, it is found that the magnetic field versus range plots have two distinct regions with very different slopes. This effect is attributed to coupling of the cylindrically spreading coal seam mode to a low-attenuation conductor guided mode. As a result, voice communications range between mobile transmitters can extend several thousand meters. The use of MF for mine communications is discussed.

By W. H. Eddy

Laboratory batch and small-scale continuous flotation tests were con-ducted by the Bureau of Mines on a mica waste tailing from Kings Mountain, N.C., to determine the feasibility of producing high-quality mica, feldspar, and glass sand. Mica was recovered by two methods; one was by flotation in an alkaline circuit, which produced a mica concentrate assaying 92.0 percent mica with a recovery of 87.l percent, and the other by flotation in an acid circuit, which produced a mica concentrate assaying 91.0 percent mica with a recovery of 79.4 percent. Continuous flotation processing yielded a feldspar concentrate assaying 1.10 percent Na20 and 13.50 percent K20, with recoveries of 66.4 and 80.6 percent, respectively. The feldspar tailing was high-quality quartz glass sand analyzing 98.6 percent Si02 and 0.02 percent Fe203.

Jan 1, 1969

Reduce the dust levels to which jacksetters and helpers on auger mining sections are exposed by identifying viable, effective methods for control-ling respirable dust on these sections. Approach The Bureau of Mines con-ducted laboratory tests and respirable dust surveys to identify the factors that distinguish clean auger mining operations from dusty ones. Study Results Results of the Bureau's study revealed that ventilation is the most important element of auger mining dust control. The four must important venitilation parameters are airflow, curtain configuration, curtain setback, and curtain installation.

Jan 1, 1988

Native asphalt was produced in 1977 by six companies in four States. Leading States were Texas and Utah. Output declined 39% to 1,237,000 tons valued at $18,874,000. Bituminous limestone was produced by Whites Uvalde Mines and by Uvalde Rock Asphalt Co. in Uvalde County, Tex.; by Southern Stone Co. in Colbert. Ala.; and by Barton County Rock Asphalt Co. in Barton County, Mo. Gilsonite was produced by American Gilsanite Co. in Uinta County. Utah, and by Ziegler Chemical and Mineral Corp. in Weber County. Utah. The asphalt was used for streets and roads, and for other purposes.

Jan 1, 1980

"At the request of the Anthracite Institute, the United States Bureau of Mines during February, March, and April 1935, made a field survey of commercial anthracite shipped from collieries scattered throughout the Anthracite regions. In all, 268 samples were taken at 41 breakers from Carbondale at the northern end of the field to Pottsville at the south. These collieries ship approximately 50 percent of the industry’s total production. The geographical distribution of the breakers sampled was as nearly as practicable in proportion to the tonnage of the companies from each region cooperating in the plan.The following are the weighted average analyses, by sizes, of the samples taken in this survey;"

Jul 1, 1935

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

B 5 Typical Input - Ouput The input data and the printed output for case 8 of the simulations (Section A.4) are shown in the following. The branch, level, node, miner and hoist numbers mentioned in the input and output refer to the corresponding numbers in Figures A-3, A-4 and A -5, The plotted ouput, already shown in Figures A,11 and A-12 is not repeated. The input data shown does not include the following simulation parameters: DTIME = 0, 05 FTIME = 130 JPLT(K) = 1 for K = 1, 2, 3 0 for other K TPLSTR = 0.0 TPLST P = 130

Jan 1, 1976

By W. E. Anable

A 180° magnetic deflection residual gas analyzer mass spectrometer with a mass range of 2 to 200 amu was used to study the nature of gases evolved during arc and electron-beam melting of certain reactive and refractory metals. The partial pressure of residual gases over molten Mo, Hf, Ti, and Fe, was found to be similar: Water and hydrogen were evolved from the samples and from the furnace components, carbon dioxide and carbon monoxide resulted from deoxidation of some of the melts. Argon and acetone were residuals in the system, and methane was a decomposed organic compound from the oil diffusion pump.

Jan 1, 1969