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This report, 27th in a continuing series1, describes Bureau of Mines research and technologic work on coal and related investigations during 1962. While the brief discussion in each section of the report presents only the highlights of Bureau work during the year, details of many investigations can be found in publications cited in this text. Other work, reported here for the first time, will be covered in greater detail in later publications. Recent trends in coal research and technology both at home and abroad were reviewed in several publications2. Bureau research, as in the past3, continued to stress improved methods of mining, preparing, processing, and using coal. The program included a wide variety of applied and basic studies for developing information useful to the coal mining industry and the coal consumer while promoting wise conservation and utilization of our coal resources.

Jan 1, 1963

By Robert L. Lagace

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

The Bureau of Mines in the Department of the Interior is increasingly concerned with the safety and health of personnel engaged in coal-mining operations, particularly below ground. The Bureau is also concerned with improving the utilization of domestic mineral resources, and reducing the environmental impact of mineral operations. One obvious way to improve safety and minimize health hazards would be to eliminate coal mining entirely by bringing the energy value of the coal to the surface in some other way, such as by partially burning it underground to form combustible gases and bringing these gases to the surface, where their energy content can be put to use. This technique might also improve the utilization of the coal resource. ? Accordingly, the Bureau of Mines, interested in re-evaluating underground coal gasification technology in terms of current and expected conditions in the United States, requested Arthur D. Little, Inc., (ADL) to appraise the technology to determine: ? Whether the current (1971) state of the technology offers a technically feasible method for gasifying coal underground that is applicable to the reserves of bituminous and lower rank coals in the United States. ? Whether a program of research and further development of the technology could ultimately make it a technically feasible alternative to current open-pit and underground coal mining operations. ? What the nature and cost of further research and development work in the technology should be.

Jan 1, 1971

By John H. Johnson

This report covers the third and final year of work conducted under U. S. Bureau of Mines Grant G0166027, "Monitoring of Mine Air Pollutants". The report discusses work performed in three areas. These are the White Pine Mine (WPM) Experimental Unit, diesel mine-vehicle tailpipe emissions monitoring, and mine ambient air concentration data analysis. The WPM experimental unit was used to study diesel exhaust stratification in an 80 foot long dead-end heading while loading ore with a Wagner ST-5D scoop train LHD. The MTU Mine Air Monitoring Laboratory (MAML) was used to gather temperature and CO2 concentration data at 10 locations. Three different ventilation conditions were compared. The data substantiate the presence of strong buoyant forces of the hot exhaust gases which result in temperature stratification in dead-end headings. The diesel mine-vehicle tailpipe emissions monitoring study involved laboratory measurements of diesel undiluted exhaust pollutant concentrations by the portable tailpipe emissions measurement apparatus (EMA) assembled for in-mine use. The results were compared with simultaneous measurements by standard laboratory exhaust monitoring instruments. These results indicate that accurate field source quality control measurements can be obtained for CO2, CO and NO but NO2 results were low for all engine conditions. The mine ambient air concentration data analysis study included analysis of diesel pollutant concentration data in the Orchard Valley Mine air and comparison of the results with data collected earlier in the White Pine and Brushy Creek mines. The analysis included preparation of lognormal frequency distributions and calculations of C02-based concentration ratios and correlations. In the three mines compared, pollutant concentrations are distributed quite similarly, and the concentrations appear to be controlled to present standards.

Jan 1, 1979

By Jos. R. Guiteras

This paper has been written to describe briefly the mining and milling of gold and silver ores in the Black Canyon and neighboring mining districts in Yavapai County, Ariz. The description of present operations is the result of a 10-day visit to the region by the writer in March 1936. Acknowledgments The author is indebted to earlier writers on the geology and mining in this regions and to the mine managers and their staffs, whose courteous cooperation has made possible the assembling' of material for this paper. Individual acknowledgments are made in the text.

Jan 1, 1936

By Irving Wender

This report describes Bureau of Mines experiments and reviews the work of others on the exposure of coal and coal-derived products to gamma rays and some other types of radiation. Results are presented on tests of three bituminous coals and a lignite that had been pulverized to minus 200-mesh particles and exposed to 1,000 megaroentgens of gamma irradiation from spent-fuel elements of a nuclear reactor. Of about 20 chemical and physical tests in Bureau work, only mass spectrometry of gases evolved during vacuum pyrolysis of the coals to 450° C gave results indicating differences in the irradiated and unirradiated samples. Mass-spectral distribution curves for CO and CO2 evolution showed fewer irregularities (reversals of curvature) for irradiated coals; thus, mass spectrometry appears to be the most sensitive method for determining radio-induced changes in coal. It is concluded that coal is not significantly altered by gamma irradiation owing to the resistivity of its highly condensed ring structure. High-level gamma irradiation, therefore, is unlikely to prove advantageous in coal processing and utilization. Specially treated coals, because of resistivity of coal to radiation damage, may be useful as an absorbent in processing radioactive wastes.

Jan 1, 1968

By E. J. (Kirk) Conway

The objectives of this project were to: (1) determine the extent to which maintainability design concepts and principles have been applied to the design of underground coal mining equipment, (2) try to assess its impact on productivity and personnel safety, and (3) develop maintainability guidelines to enhance the design of new or rebuilt equipment. An equipment design review was completed at ten operational coal mines. The purpose was to identify design approaches and features that enhanced and degraded the maintenance process. Mine management, safety, and maintenance personnel were also interviewed to identify machine specific design problems. Six original equipment manufacturers were visited and the procedures used to enhance the maintainability of Their equipment discussed. Volume I of the Final Technical Report presents an overview of procedures and protocol used and a summary of the findings. Volume II includes the maintainability design guide for mobile underground mining equipment.

Jan 1, 1988

By Thomas E. Doerfler

Information and data related to the occurrence of fatalities due to major disasters in metal/nonmetal underground mines were analyzed. Standard statistical methods were used to estimate the probability of occurrence of major disasters, and to examine the relationship of disasters to injury statistics published annually.

Jan 1, 1980

By S. H. Ash

THE INUNDATION of anthracite reserves in the Eastern Middle field of Pennsylvania affects the life of the anthracite industry in this field; it also influences the economic status of people, communities, and industries that depend wholly or in part upon anthracite for their livelihood. The trends of production and of employment in the anthracite-mining industry in this field are downward, and they probably will continue in this direction. The reserves have been depleted to the extent that the end of the active life of the industry as a. major economic factor is approaching. By removing the water in those pools where it can be done economically, the future of this industry may be extended somewhat.

Jan 1, 1950

By R. H. Thompson

Preliminary safe distances for blasting wiring from typical electromagnetic sources are presented. The distances are for underground coal mines and electromagnetic sources in the frequency range below 10 MHz. The distances are based on measurements performed at 3 locations in each of 3 coal mines. The measurement apparatus, measurement procedure, measurement results and the rationale used in the calculation of the safe distances are all described. The safe distances presented are dependent on the measurement results and their interpretation. More measurements are clearly necessary to establish the validity of the suggested distances.

Jan 1, 1985

By R. W. Huber, R. C. Wiley, V. C. Petersen

"Three arc- melted ingots, two of a t itanium-7 percent manganese all oy and the third of unalloyed titanium, were forged and rolled into 3/ 4-inch plate; comparative data were obtained on these processes. The finished plate, part of which was used by the Naval Bureau of Ordnance, was tested for mechanical and other properties.These properties were correlated with sponge purity, forging technique, rolling temperature, and cooling rate from the rolling temperature. For the alloy material, transformation data were obtained, and their age-hardening characteristics were studied. The temperature-impact relationship was established for rolled sections from all three ingots.INTRODUCTIONArc -melted ingots of unalloyed titanium and a titanium-manganese alloy were fabricated into plate under closely controlled conditions by personnel of the Metals and Alloys Section, Physical Metallurgy Branch, Bureau of Mines, College Perk, Md. This program was cosponsored by the Naval Bureau of Ordnance. Bureau of Mines interest lay in correlating the processing procedures with the mechanical properties of the finished plate.Considerable data have been published recently on constitution diagrams and properties of titanium-manganese alloys in genera1. 3/ 4/5/6/ However, little if any correlation between processing schedules and end results has been published, particularly with respect to the present commercial production of the proprietary titanium manganese alloys . Several factors in the production of titanium and titanium alloys have a pronounced influence on the physical and mechanical properties of the finished product: (1) The degree and nature of impurities in the base materials, ( 2) the amount of impurities introduced during the melting cycle and their distribution, (3) the homogeneity of the alloy, (4) forging, (5) rolling, and ( 6) final heat-treating cycles. All of these item£ are important from a metallurgical standpoint in producing the desired end properties in the metal."

Mar 1, 1955

By A. Galaitsis

This report summarizes part of the work performed under the USBM Contract No. H0155113, "Noise Abatement of Continuous Mining Machines." It reviews, briefly, the aboveground tests performed on a Jeffrey 120M conveyor that were documented in Vol. I of the subject contract; and describes the performance of treatments implemented on underground equipment. The noise level at the operator's position in the aboveground-test facility was reduced from 101.5 to 91 dBA using treatments with satisfactory - aboveground - durability. Extensive underground evaluation has been performed only on the constrained layer damping, which has reduced the conveyor noise by 2 to 6 dBA depending on the operating conditions, and has been shown to be sufficiently durable. Other promising candidates for exploratory evaluation include resilient layers for the top/bottom decks, and smoother discontinuities between adjacent conveyor sections.

Jan 1, 1983

"To prevent the propagation of mine explosions, the Bureau of Mines recommends:1. That all coal and lignite mines, except anthracite mines shall be rock dusted.2. That rock dust shall be distributed upon top, bottom, and sides of all underground openings of every description, to within. at least 4o feet of all working faces and the areas not rock dusted shall be kept wet.3. That the rock dust shall be maintained in, such quantity that the incombustible material in representative samples of dust collected shall not be less than 65 percent. Where methane gas is present in the ventilating current, the minimum percentage of incombustible matter in the mine dust shall be increased 1 percent for each 0.1 percent of methane.4. That when the rock dust in any area becomes caked so thatit cannot be dispersed readily as a cloud in the air, that part of the mine shall be redusted immediately.5. That the dust to be used shall not contain more than 5 percent of combustible matter nor. more than 25 percent of quartz or free silica; all of the dust shall pass through a sieve having 20 meshes per linear inch and 60 percent or more shall pass through a sieve having 200 meshes per linear inch; the dust shall not absorb moisture from the air to such an extent as to cake and destroy its effectiveness as a dry dust.6. That rock-dust barriers shall not be regarded as a substitute for generalized rock dusting.Research and experience have shown that maintenance of an adequate percentage of rock dust in all underground openings, whether gassy or not, of bituminous and subbituminous coal and lignite mines (anthracite dust does not propagate explosions) is the best means of preventing coal dust explosions. In rare instances where all fine coal particles on the floor, ribs, roof, and timbers are in a muddy condition continuously rock dusting is unnecessary.The term ""underground openings"" refers to all unsealed openings whether they contain track or not, and includes rooms, entries, crosscuts, breakthroughs, rock tunnels, slopes, haulageways, airways, and travelingways. The sealing of unused or abandoned parts of a mine in accordance with Mine Safety Board Decision avoids the necessity of rock-dusting the sealed-off openings.The kind of rock dust to be used should have the approval of the State Mine Inspection Service. Pure limestone or pare dolomite produces the best rock dust, as these dusts have low silica content, little tendency to cake, and a light color that aids illumination. To reduce tendency to cake it is preferable that not more than 75 percent of the dust pass the 200-mesh sieve. All sieve sizes are those of the Tyler screen scale. If the mine personnel is repeatedly exposed to breathing high concentrations of the dust, the percentage of free and combined silica should be as low as possible, preferably less than 5 percent. Persons engaged in the application of rock dust should wear approved dust respirators as listed in Bureau of Mines Information Circular 7030 or revisions thereof."

Mar 1, 1940

By David D. Rabb

A report on location, sampling, assays, mineral examination, amenability leach tests, and evaluation of certain mine dumps in Mohave County, Arizona. Extractions of greater than 30 percent of the gold and silver were achieved during simulated heap leaching of selected mine dump material. Consumption of reagents was relatively low and results suggest leaching of prepared heaps is technically viable and could be economically attractive.

Jan 1, 1980

By J. Douglas Causey

In 1988, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied part of the 12,740-acre Blue Canyon Wilderness Study Area (OR-003-073) in order to evaluate its identified mineral resources. The study area is in Malheur County, OR, about 27 miles northwest of Jordan Valley. The study area is underlain by Tertiary welded tuff, tuff, perlite and tuffaceous sedimentary rocks capped by basalt. Jasper has been mined from several localities. Some mining has been done by hobbyists. However, the area has been covered by mining claims since 1964, with mining done by commercial operators. This region has been a source of "Owyhee picture" and other similar jaspers. More recent exploration has focused on the gold potential of nearby areas such as Quartz Mountain and Red Butte.

Jan 1, 1989

By Richard L. Fowler

[Study and development of sensing techniques and sensors were performed to aid shuttle car drivers in detecting, obstacles and in guiding the car along the face haulage route. Microwave, acoustic, and optical sensing techniques were considered as part of the feasibility study for obstacle detection. Various guidance techniques, including wire-following and rib-ranging were investigated. Active optical sensing was selected for obstacle detection to obtain the bear overage and sharp angular cutoff characteristics required within the packaging limitations defined by the shuttle car configuration. Rib-ranging guidance was selected to achieve completely self-contained shuttle car system which responds to the mine geometry without need for wires, stripes, or other path defining devices. Extensive hybrid computer simulation runs were performed to valuate various guidance techniques during the feasibility study. Subsequent simulation rues were performed to establish parameter values for the rib-ranging guidance system. The obstacle detection and guidance system was designed, fabricated and installed on a standard shuttle car. The system satisfied all applicable permissibility requirements of Schedule 2G. An experimental permit was issued to Bendix for operation in an underground coal mine. System evaluation tests were performed first above ground at the Bendix Research Laboratories. The simulation model was validated by these runs. Final testing wan performed underground in an operating mine with an experienced shuttle car driver. All sensors successfully demonstrated Chi predicted performance capability during underground face haulage tests. Dust did not Impair system performance and lens cleaning was not required during working shifts. Further development is required to achieve the desired obstacle detection performance Closed loop steering control with manual override is recommended o: mended for the lateral guidance e system. The guidance system should be an invaluable aid to low-coal shuttle car drivers where continuous mining machines are utilized.]

Jan 1, 1973

By Bryan R. Carmenati

This report documents the need for formal health and safety, and equipment operations training in the mine construction industry. The outlines, objectives, and training texts were developed based on the recommendation of needs of mine construction personnel, and those of Dames and Moore (Safety Analysis of Shaft Sinking operations, 1977) and Kinton, Inc. (A Training Program for Conventional and Raise Drill Construction Personnel; Phase I, 1979). The training material samples contained herein (and under separate cover in its entirety) are designed to improve the safety and production of those in mine construction. An instructor-directed presentation is recommended. The results of the study are presented in the Findings and Recommendations section of this report.

Jan 1, 1982

By James M. Spear

The U.S. Bureau of Mines and the U.S. Geological Survey conducted a mineral survey of the Elk Creek RARE II area during the summer of 1981. The study area encompasses 18,900 acres [29.5 sq mi (7,680 ha)] along Elk Creek, 18 mi (30 km) southeast of Covello, California. No mineral resources were identified by the U.S. Bureau of Mines during this survey. Assay results of samples taken in this area indicate only trace amounts of manganese and chromium. No radioactive or fluorescent minerals were detected. No oil and gas, coal, or geothermal leases have been recorded for the study area.

Jan 1, 1982

By Donald O. Capstick

A mineral survey of a 5,700-acre portion of the 11,510-acre Upper Deep Creek Wilderness Study Area (ID-111-44B) in southwestern Idaho was conducted by the U.S. Bureau of Mines in 1985. No mining claims have been located, no minerals have been produced, and no resources have been identified in the study area. Three reconnaissance samples of alluvium from the Deep Creek drainage contained $0.21, $0.22, and $2.72 per cubic yard in placer gold, higher than usual for the Owyhee River canyonland area. The samples of near-surface material contained very fine gold in values too low to support large-volume commercial placer operations, but the quantity and size of the particles of gold in the alluvium is expected to increase near bedrock. Consequently, the area may be a target for recreational as well as small commercial suction dredge operations. The physical characteristics of the individual pieces of gold (bright and angular) indicate that it may have recently come from an unidentified nearby source.

Jan 1, 1986

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