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By W. L. Dare

This publication is one of a series by the Federal Bureau of Minus describing methods and costs of minim, uranium on the Colorado Plateau. The La Sal mine is in the Big Indian mining district, about 29 miles southeast of Moab, San Juan County, Utah. The claims that encompass the mine were located in March 1953, and the La Sal ore body was discovered as a result of a drilling program begun in August 1953. The mine is owned by the La Sal Mining & Development Co., a subsidiary of the Homestake Mining Co. Homestake continued the drilling program and in May 1954 began sinking a 572-foot shaft and constructing a surface plant. The plant and shaft were completed in October 1954. The La Sal ore body is in the Chinle (Triassic) formation. it is tabular and dips with the enclosing beds about 8° southwest. The ore body is generally 4 to 8 feet thick but in a few places is as much as 20 feet thick it is being developed by a series of strike drifts and dip inclines, driven within the ore stratum on about 100-foot centers. A haulage level driven beneath the ore body is connected by raises to the upper workings.

Jan 1, 1957

By By Staff

"These proceedings consist of papers presented at a Bureau of Mines Technology Transfer Seminar on postdisaster survival and rescue research. Several seminars are held each year to bring the latest results of Bureau research to the attention of the mining industry as quickly as possible.INTRODUCTIONThe postdisaster research program is directed toward research and development of technology and equipment that increases the chances of a miner surviving or being rescued after an underground mine disaster. A disaster is an accident of major proportions, and it may result in the entrapment of miners whose normal egress from the mine is cut off. This often necessitates a rescue operation and a means of keeping the trapped miners alive while they await rescue. The Bureau is currently pursuing research to develop the technology that will enhance the ability of miners to survive such an occurrence. The research is divided into two basic problem areas, survival and rescue. Both areas are concerned with the inability of miners and rescue teams to cope with the postaisaster environment, such as toxic gases, unstable roof conditions, water flooding, and lack of oxygen. In addition, research is also conducted to find ways of locating and quickly reaching trapped miners. Most of the research conducted by the Bureau has been directed toward the postdisaster problems associated with coal mines. However, most of the research results are also applicable to noncoal mines as well.The papers presented in these proceedings address some of the recent research conducted by the Bureau of Mines that has been directed toward the postdisaster problems outlined above. The topics covered range from an overview of the technology developed for oxygen selfrescuers to training programs for mine rescue. Any questions or comments pertaining to this research are encouraged and appreciated. Open file report (OFR) references in the proceedings listed as available from NTIS may be obtained from the National Technical Information Service, Springfield, Va. 22161, and are also available for reference at Bureau of Mines facilities in Denver, Colo., Twin Cities, Minn., l3ruceton and Pittsburgh, Pa., and Spokane, Wash.; the Department of Energy facility in Morgantown, W. Va.; the National Mine Health and Safety Academy, Beckley, W. Va., and the National Library of Natural Resources, U.S. Department of the Interior, Washington, D.C."

Jan 1, 1982

By L. L. Oden

The Bureau of Mines analyzed vapor-aluminum-diffused stainless steels prior to conducting corrosion measurements in severely sulfidizing environments. These studies were conducted in response to the national need to better control the environmental and economic costs of corrosion. Specimens of a ferritic alloy and austenitic alloys types 316 and 310 were treated by a proprietary vapor-aluminum diffusion process and a dual vapor-aluminum diffusion process. Weights and dimensions were recorded before and after treatment, and comprehensive metallographic, X-ray, and electron micro-probe analyses were conducted for both single-and dual-vapor-aluminum-diffused specimens. Surface aluminum concentrations ranged from 26 to 34 wt-pct for all alloys. Dual treatment increased the quantity of aluminum per unit area by a factor of 2 and increased the depth of penetration by a factor of 3. The aluminum-diffused region of the ferritic alloy was single-phase aFe solid solution that was ordered on the surface, whereas two distinct diffusion layers were ob-served on the austenitic alloys. The outer layer comprised aFe solid solution that was ordered on the surface, and the inner layer was a two-phase mixture of aFe solid solution and the interrnetallic compound AINi.

Jan 1, 1982

By Everett A. Sondreal

Data are presented on the characteristics of lignites with emphasis on the composition and fusion properties of the ash. Differences in the analyses of commercial-grade lignites are related primarily to variations in moisture and ash contents. Lignite ash is generally characterized by high concentra¬tions of alkaline earth oxides and a greater tendency for retention of sulfur in the ash than higher-rank coals. Composition of ash varies significantly within and between mines. The differences within mines are significant for short distances and may be eliminated under certain circumstances by normal mixing occurring during mining. The sulfur in lignite averages 0.6 percent and is found primarily in the organic or pyritic forms with only a trace of the sulfate. During the stan¬dard laboratory asking procedures, from 60 to 100 percent of the original sul¬fur is retained in the lignite ash. Trace elements, such as uranium and germanium, in the ash from commercial¬-grade lignites are present in low concentrations, but others, primarily copper and silver, are present in specific samples in concentrations approaching those found in some commercial ores.

Jan 1, 1968

Provide a means to (1) rapidly disconnect a multifunctioning signal channel from a multichannel data collection system, (2) protect electronic devices from damage while causing the minimum amount of data collection disruption, and (3) operate electronic devices under gassy mine conditions. Background Data collection system instrumentation and cables are often located in hazardous areas of underground coal mines. As a result, frequent damage to the instrumentation cables occurs from roof falls, heavy equipment, and the relocation of air, water, and power lines. A similar problem exists in surface areas where cables and instrumentation can be damaged by animals and by vehicle traffic. Without a circuit-breaking feature, the damaged cables could cause instrumentation to be ruined, cause power supply failure, and otherwise disrupt data collection in some situations the lack of a circuit-breaking feature might cause an ignition in a methane atmosphere.

Jan 1, 1990

By A. T. Iannacchione

Roof-rock instability in advancing sections of underground coal mines is a major contributing factor to accidents resulting in fatalities and injuries. Such roof-rock conditions can also result in loss of production due to additional cleanup time and increased amounts of reject material. The Bureau of Mines is investigating fundamental geologic factors affecting coal mine roof-rock instability in order to develop techniques to predict zones of potential unstable roof-rock. Two distinct directional trends of unstable shale roof-rock in a mine working the Upper Kittanning Coalbed are delineated: one trend is associated with the sandstone-shale transition zone, the other with a fault system. The unstable shale roof-rock associated with the transition zone, a consequence of differential compaction, is comprised of slickensided roof-rock. Whereas, the unstable shale roof-rock associated with the fault system, a consequence of structural deformation of the strata, is comprised of fault planes. These faults, small in comparison to the sandstone-shale transition zone, are difficult to delineate with a standard drilling program. Trends of the transition zone associated with the sedimentary facies change are projected into unmined portions of the coalbed with the aid of exploration core data.

Jan 1, 1981

By K. E. Stanfield

Oil-yield results are presented for 65 oil-shale sections in Piceance Creek Basin, Colorado, sampled during the period 1957 through 1963. Including previously published data, oil-yield results for 203 sampled sections have now been released by the Bureau of Mines to aid in appraising the shale oil potential of the basin. Oil yields of core samples (135 sets) were regarded as reliable bases for appraising the Mahogany-zone interval, but only 5 sets of cores sampled the deeper, lower-zone oil shales. Drill cuttings (68 sets) sampled the lower-zone oil shales, but their oil yields are principally indicative and should be confirmed by analyses of cores. More complete core sampling of the lower-zone oil shales is needed.

Jan 1, 1967

By L. B. Berger, W. P. Yant, R. R. Sayers

"At the request of the Chesapeake & Ohio Railroad Co. a number of tests were made to determine the temperature, humidity, and composition of the atmosphere in certain tunnels of that railroad between Clifton Forge, Va., and Hinton, W. Va. The purpose of these tests was to determine conditions in the cabs of freight locomotives while pulling trains through these tunnels. Tests were made of two types of locomotives, classified by the railroad company as the H-6 and H-7. Both are of the Mallet type, but the H-6 class has one pair of cylinders operating at boiler pressure and the other pair compound, whereas the H-7 operates all four cylinders at boiler pressure, thereby exhausting steam at a higher temperature than the H-6. It was desired to determine the relation between conditions on the H-6 and H-7 engines under comparable conditions of operation. This information supplements previous tests by the Bureau of Mines, discussed in its Reports of Investigations Serial No. 2624, entitled, ""Temperatures in Cabs of Freight Locomotives Passing Through Tunnels of Chesapeake & Ohio Railroad, 11 by s. H. Katz and E. G. Meiter, July, 1924. Three incidental tests of passenger engines were also made."

Feb 1, 1928

By James R. Boyle

The value of Alabama's nonfuel mineral production in 1987 was $446.6 million, an increase over that of 1986 and the first increase in 3 years. Alabama was second in the Nation in production of bauxite and ferroalloys; third in bentonite, crushed dolomite, crushed marble, and fire clay; and fourth in masonry cement. Trends and Developments.-Employment in the minerals industry remained relatively low for the second year even though the overall unemployment rate dropped to 7.9% by December. Employment in mining and primary metals dropped about 10% and 2%, respectively.

Jan 1, 1989

The latest Active List of Permissible Explosives and Blasting Devices was published in July, 1929, as Bureau of Mines Report of Investigations 2947, 2 under the title or "Active List of Permissible Explosives and Blasting Devices Approved Prior to June 30, 1929.' Subsequent Reports of Investigations 2253, 2958, 2962, 2972, 2988, 2992 and 3000, were issued to record the official actions taken during July, August, September, October, 1929, and January, February, and March, 1930. No changes were made during November and December, 1929, and April, 1930. The following additional changes in the list recording the actions taken during May, 1930, are now authorized. [ ]

Jan 1, 1930

By Gertrude N. Greenspoon

Legislation and Government Programs.-The Occupational Safety and Health Administration (OSHA) held public hearings in early 1975 on proposed standards for exposure to inorganic arsenic. The findings obtained at the hearings will be considered to promulgate emission standards. Domestic Production.-Arsenic trioxide (As203) was produced domestically only at the Tacoma, Wash. copper smelter of ASARCO Incorporated. Production data cannot be published. Output rose 9% over that of 1974, shipments were less than half those of 1974, and stocks rose 31 %. Production of arsenic metal, begun by ASARCO in August 1974, continued in 1975.

Jan 1, 1977

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Jan 1, 1975

By F. N. Kissell, C. D. Litton

This study ranks the factors impacting survival during a coal mine fire. It bas already been established that reducing time delays is the most important factor in saving lives. Consequently every event during afire is measured in terms d its duration, and the effectiveness d any action taken to improve survival is measured in terms d the time it saves. By ranking actions according to time saved these authors found that a comhination d actions was most effective. This combination was: • installing lifelines. • moderately decreasing air leakage and • decreasing the fire growth rate. Changing ventilation leakage alone was much less effective, as was altering the CO (carbon monoxide), sensor alarm threshold. These results confirm an earlier fault-tree study on escape from mine fires. The fault-tree study bad shown that, with the exception d delays, single factor changes have minimal impact. Significant reductions in fire fatalities only take place with multiple factor changes.

By Robert L. Lagace, Alfred G. Emslie

This report presents a mathematical model for the propagation of UHF radio waves in the large cross-section tunnels of a room and pillar limestone mine, and describes the analysis of a small amount of propagation data obtained in a limestone mine. The model and analysis is based on the waveguide mode theory developed earlier for the transmission of UHF waves in coal mine tunnels, with allowance for propagation losses due to refraction into the tunnel walls, to scattering by wall roughness, and to long range random tilt of the walls. Propagation around corners and through pillars is also examined based on a ray theory approach, together with the beneficial effects of placing reflectors at intersections to significantly reduce corner losses. The theory is found to be in fair agreement with the data; however, additional in-mine measurements are needed to provide a more conclusive test of the model.

Jan 1, 1979

By Martin Hertzberg

The concept of limit burning velocities is being used to formulate a quantitative theory of flammability limits. Competing and complicating processes dissipate power from a combustion wave and quench propagation at some characteristically low limit velocity. Two earlier reports dealt with process (a), natural convection (RI 8127); and with process (b), conductive-convective wall losses (RI 8469). This report considers process (c), radiative losses, and process (d), selective diffusional demixing. The limit burning velocity for radiative losses is [(SU)c ~ e cp] It is normally not a significant process for premixed gas flames; however, for laminar flame propagation in a gravity-free environment, it is the only loss process present. Accordingly, limit velocities at zero gravity should be much lower than on earth, and premixed gases should be flammable over wider composition ranges. For highly emissive dusts, soot, or ash-forming flames, radiative losses are significant even under normal gravity conditions. Selective diffusional demixing is a complication that manifests itself in the form of cellular flame structures and wide gaps in composition between upward and downward propagation limits. It induces a burning velocity shift (?Su)d, causing the flame to behave as though it were richer or leaner than its initial composition, depending on whether the fuel or the oxidizer mole¬cule has the higher diffusivity. A simple pertubation analysis shows that the process generates stable cellular flames whenever [dsu] > 0, where ci is the concentration of the reactant with the higher diffusivity. The same analysis indicates that at the opposite stoichiometry, where [dcu] < 0, laminar structures are stabilized. A simple formula for the diameter of cellular flames is derived, which predicts that dcell should vary inversely with the product of the diffusivity difference Di -DJ, and the burning velocity slope [dc ]. Those predictions are in good agreement with the available data. Buoyancy forces for upward propagation induce flame front curvature, and hence buoyancy and selective diffusion are mutually supportive in upward propagation. Thus large gaps in composition between upward and downward limits are present in those composition domains where cellular flames are stable.

Jan 1, 1981

By J. A. Organiscak

Two types of airflow splitting methods for improving longwall dust control were investigated by NIOSH&apos;s Pittsburgh Research Laboratory. These methods included a translucent mesh barrier and a staged spray barrier system to confine the shearer-generated dust to the coal extraction side of the longwall face while maintaining a cleaner split of airflow on the opposing worker walkway side of the longwall face. The translucent mesh barrier was shown to provide notable dust control effectiveness up to 60 m downstream of the shearer in both the laboratory experiments and a longwall field evaluation, provided the mesh barrier remains relatively parallel to the airflow. The staged spray barrier system showed marginal dust control effectiveness in the laboratory and subsequently was not field tested.

By G. B. Atkinson

The Bureau of Mines, in cooperation with McDermitt Mine, investigated a method for recovering mercury metal from mercury sulfide flotation concentrate by a hydrometallurgical technique. This preliminary report shows the feasibility of leaching mercury with a cupric chloride solution and electrowinning mercury from the solution. Proposed chemical reactions are shown in equations 1 through 3: 2CuC12 + HgS + 2CuCl + HgC12 + S°; (1) electrolysis HgC12 ?Hg + C12; (2) 2CuC1 + C12 ? 2CuC12. (3) A bench-scale leaching-electrowinning apparatus capable of treating 2.36 kg of sulfide concentrate in 11 days was operated continuously. An acid chloride solution containing, in grams per liter, 70 Ca, 60 Cu, 30 Fe, and 80 Hg was used as both leachant and electrolyte; 99.5 pct of the mercury was solubilized from the sulfide concentrate. Electrolysis of the leaching solution recovered mercury metal at an average current efficiency of 32 pct and an average energy consumption of 1.2 kwhr/lb Hg. Results from a preliminary economic evaluation indicated that a plant producing 31,500 flasks of mercury per year would have a capital cost of $3.7 million and an operating cost of $62 per flask of mercury.

Jan 1, 1983

By Northcutt Ely

Jan 1, 1961

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

D. 1 Most Effective Salts A. Ammonium Phosphates Monammomium phosphate and diammonium phosphate (salts of ortho phosphoric acid) are superior to the triammonium salt in fire-resisting properties. Of these two, the monammomium salt is chemically the more stable. It is also held very retentively by a number of woods, thus reducing leaching out of the salt if exposed to water. Saturated aqueous solutions of mon- or di-ammonium phosphates have vapor preservatives corresponding to an atmospheric relative humidity of 9Z to 93 percent, the wood, will, therefore, not attract any moisture at humidities below this figure. Low concentrations (1 lb dry fire-retardant per cubic foot of the dry, treated timber) will stop flame and high concentration (5 lbs. per cubic foot) will prevent smoldering. B. Ammonium Sulphate In low concentrations ammonium sulphate has only a small effect on flame propagation, but its effect is marked when concentrations of the order of 20 percent are employed. It has no appreciable effect on smoldering. It is more corrosive to metals than are the phosphates, but is less corrosive than ammonium chloride or magnesium chloride. It is possible to leach it out of wood by prolonged and continuous action of water The vapor pressure of the saturated solution corresponds to 81 percent atmospheric humidity.

Jan 1, 1976

By Fred Garcia, William P. Diamond

As part of its mine safety and health research program, the National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, has been investigating the geologic and mining factors influencing methane gas emissions associated with longwall mining. A primary focus of this research has been the consequences of increasing longwall panel dimensions, particularly face width, in gassy coalbeds. Continuous longwall face emission monitoring studies were conducted at two adjacent mines operating in the Pocahontas No. 3 Coalbed, where longwall faces were to be extended from 229 to 305 m (750 to 1,000 ft). Average longwall pass methane emission rates for 229-m (750-ft) wide faces were 61 % (0.072 m31sec (153 cfm)) higher at the VP-3 Mine than at the VP-1 Mine. It was predicted by regression analysis of methane emissions data from 229-m (750-ft) wide faces that extending faces to 305 m (1,000 ft) would increase methane emission rates by only 7%, or 0.009 m3/sec (20 cfm), to 0.144 mysec (304 cfm) at the VP-1 Mine. In contrast, it was predicted that extending faces to 305 m (1,000 ft) at the VP-3 Mine would increase methane emissions by as much as 13%, or 0.029 mysec (65 cfm), to 0.268 dlsec (567 cfm).

Jan 10, 1999