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By R. L. Rock

The Bureau of Mines conducted radiation-ventilation studies in six large underground uranium mines to investigate the extent of radon-daughter exposure experienced by the miners and to analyze the ventilation systems to set what changes were required to achieve recommended radiation standards. The studies entailed tracing and measuring the mines' ventilating air, quantitatively and qualitaitively, from its entrance into the mines, through production areas, and lack to the surface. Pressures consumed in creating airflow through mine circuits were determined by altimeter surveys. Air quantities were measured with anemometers or by chemical smoke cloud methods. Air quantities delivered through tubing were determined using U-tube water gages to magnahelic gages to measure velocity pressures. Radon-daughters were filtered from mine air to measure alpha activity; activity levels were converted to "working levels," the established unit for reporting miner exposure. Attention was given to locating unnecessary contamination influx sources and recirculating air. The radiation-ventilation surveys showed that where basic principles of food ventilation were not followed, high alpha radiation levels invariably resulted. Some mines required more primary air for controlling radiation levels throughout active areas, but more efficient use of available air was generally possible. Premature contamination of intake air was prevalent where development Openings intersected ore or passed by worked-out stopes. Several auxiliary systems were inefficient in secondary distribution, recirculating air already too highly contaminated for ventilation. Many got these common problems can be traced try the lack of dine planning with radiation control in mind.

Jan 1, 1969

By E. R. Bauer

The U.S. Bureau of Mines is investigating strata interactions associated with mining of multiple coal beds to provide the mining industry with improved methods of planning and developing multiple coalbeds, conserving resources, and increasing the safety of underground coal mining. This study involves analytical predictions and underground observations of longwall development ground control problems at a south-central Pennsylvania coal mine affected by subsidence induced by multiple-seam mining. As predicted, strata interactions were found in upper mine areas mined over lower mine gob. Observations revealed roof deterioration accompanied by excessive water inflows in the first 170 ft after crossing the gob line as mining entered and exited the subsided area (over the lower mine gob). In contrast, superimposed mine areas and areas mined a substantial distance out over the gob showed no signs of interaction with previous lower seam mining, again as predicted.

Jan 1, 2010

By E. A. Loria

High-quality sheet of electrowon molybdenum was attained by a sequence of procedure on pressed and arc-melted crystalline powders. The procedures included high-temperature, high-vacuum sintering treatments and the use of metal deoxidizers instead of carbon to improve the mechanical properties of the molybdenum sheet. Rolled sheet 60 mils thick was evaluated by tensile and bend tests, hardness measurements, microstructures, and recrystallization treatments. After stress relieving, yield strength ranged from 85,000 to 110,500 psi (0.2- percent offset) and ultimate strength ranged from 87,200 to 117,250 psi with 4.5- to 25-percent elongation observed for arc-melted sheet, and 5.0- to 23- percent elongation observed for powder metallurgy sheet. In room temperature bend tests the sheet yielded plastically, indicating that the ductile-brittle transition point was below room temperature. The diamond pyramid hardness (DPH) of the molybdenum sheet changed from 214 to 293 DPH for the stress-relieved condition to 177 to 185 DPH for the fully recrystallized condition. The brittleness of recrystallized molybdenum, reported by other investigators as characteristic of sheet prepared from commercial-grade hydrogen-reduced powders, was not in evidence. Recrystallized tensile specimens pulled at room temperature had an average elongation of 31 percent.

Jan 1, 1966

By M. R. Geer

The Bureau of Mines surveyed the solid wastes that have accumulated from coal mining in Washington, Oregon, and Montana. Location, amount, character, and condition were determined, and both economic and environmental factors were considered. Areas covered by waste comprise 800 acres in Washington, 5 acres in Oregon, and 1,200 acres in Montana. In a few cases waste is being utilized, particularly cinder from burned refuse dumps, as fill in road construction and as a ceramic raw material. It is estimated that wastes deriving from coal mined for electric power generation by 1974 may amount to 3 million tons of washery refuse, 2.7 million tons of fly ash, and 1,000 acres of spoil banks.

Jan 1, 1969

By J. E. Cleveland

The major health concern for uranium miners is the release of radon gas and the resultant ingrowth of the short lived daughters in the mine atmosphere. Present methods of control are the utilization of mine ventilation systems for dilution and control of ingrowth time to maintain working levels below those set by regulations. This study examined pressure cycling efforts on the radon emanation. The mechanical ventilation systems were altered to allow pressure changes throughout the mine to increase radon influx during the off shifts and thus deplete the sources of radon gas. Continuous radon working level and environmental monitors, developed by the Bureau of Mines, were employed to monitor radiation and physical parameters in the mine workings. The mine ventilation system was then varied to induce radon flows during off shifts, thus, depleting the radon sources during normal production shifts. Electro-static precipitators were also tested to determine radon daughter collection efficiencies. Both radon and radon daughter concentrations were monitored and evaluated. Major problems were found in the simple mechanical operation of cleaning these units.

Jan 1, 1982

By Frederick W. Lee

List of contributing editors of Geophysical Abstracts:

Sep 1, 1932

By D. C. Dahlin

To identify and characterize potential domestic chromium resources, the Bureau of Mines investigated podifom chromite deposits along the Border Ranges Fault in southern Alaska. Part 1 of this two-part report describes an extensive field investigation and preliminary resource evaluation studies by the Bureau's Alaska Field Operations Center. This paper, part 2, describes the mineralogy of 38 samples that were collected from low-grade deposits in the Chugach Mountains, on the Kenai Peninsula, and on Kodiak Island, and presents the results of laboratory batch beneficiation tests designed to concentrate the chromite. The samples are peridotites and chromites that consist primarily of variable amounts of chromite, olivine, and serpentine. They were beneficiated by a sequence of grinding, sizing, and gravity concentration operations. Twenty-four high-chromium or marginal high-chromium chromite concentrates, six high-iron or marginal high-iron chromite concentrates, and five submarginal concentrates were produced with chromium recoveries that ranged from 37 to 95 pct. Three very low-grade samples were not beneficiated. These results indicate that several of the de- posits may be significant chromium resources, Potential precious metals association with the chromite was also investigated. Analysis of these samples indicates that the chromite deposits are not good platinum sources.

Jan 1, 1985

By Albert H. Fay, Herbert M. Wilson

The national mine-safety demonstration at Pittsburgh, Pa., was projected and undertaken in the hope that it would aid the increase of safety in the mining industry. That the national mine-safety demonstration was warranted and has served a useful purpose was evidenced by the attendance, not only at the public demonstration in Forbes Field, but also at the more special exhibit of the work of the Bureau of Mines at the arsenal grounds and at the experimsntal. mine. Nearly 2,000 persons witnessed the demonstrations and exhibits of the Bureau of Mines at the arsenal grounds on the morning of October 30, 1911. The spectators were all mine operators, miners, or persons interested in mining, and represented operations in all parts of the United States. Nearly 1,200 of these persons visited the bureau's experimental mine at Bruceton to witness ~th~explosion of coal dust. Had the weather, which was exceptionally inclement, been more favorable, there would doubtless have been a much larger attendance. At the public demonstration in Forbes Field, which· was witnessed by President Taft, from 12,000 to 15,000 persons, chiefly mining men, were present and attested their interest and enthusiasm in the minesafety exhibits by remaining throughout the proceedings, regardless of the rain which fell all the morning .. Sincethis demonstration, the organization of first-aid corps and of rescue corps has been undertaken at mines where there had previously been no such organizations. The bureau has received letters of commendation attesting the value of the demonstration in drawing· attention to the dangers and to possible means of greater safety in mining. Many of these letters have urged that the results of the demonstration be published for the guidance and instruction of those who were present. In response to these reauests the following account of the mine- BlIIeLY demonstration lias been prepared. IIi its preparation various division and section chiefs of the Bureau of Mines have cooperated. The authors acknowledge the assistance they have received from those section chiefs and other members of the bureau who contributed detailed descriptions of apparatus exhibited at the demonstration or of investigations represented.

Jan 1, 1912

By Carl R. Peterson

[In lTI n,v und I'gr'oun nllnin~ Opt'I'ali n' the high . t cost is the loading and I 3ulage of t tln-of -D"'line ot'. 01' hauling costs can be r duced signifi-cant\v with the us ~ (r \) >It corn'e)'OI' " a COnlTllOn pl'acti c i.n coal and other s 0 t'L rn I n r' a l III i, n e , '. Jf 0 vel s i z ' () f' e can bee 1 i 11.11 tl ate I rH'i 0 I' lO C n v e . in g, ]

Jan 1, 1976

By B. J. Scheiner

Oxidation procedures based on the chlorine-hypochlorite system were investigated for improving gold recovery from carbonaceous gold ores. The oxidation pretreatment prior to cyanidation was accomplished by (1) addition of sodium hypochlorite to ore pulp, (2) by addition of chlorine to ore pulp, and (3) by generation of hypochlorite in situ by electrolysis of a brine solution used to pulp the ore. Gold extraction of 90 pct was achieved by cyanidation of carbonaceous ore that had been pretreated with 20 Ib per ton sodium hypochlorite at 50° C for 4 hours. Similarly, pretreatment of the ore pulp with 35 1b chlorine per ton at 24° to 30° C and 15 hours reaction time resulted in 89-pct gold extraction by subsequent cyanidation. Concomitant studies showed that electrolyzing the pulp prepared with a brine solution was equally as effective as electrolyzing hypochlorite and chlorine for oxidizing carbonaceous ore constituents that are deleterious to cyanidation. Gold extraction of 90 pct was obtained by electrolysis when 275 lb of are was treated at 200 amp for 7 hours in an 8-to 10-pct salt solution. Power consumption was in the range of 60 kwhr per ton.

Jan 1, 1972

By John E. Shelton

Flotation tests were conducted on two samples of copper-nickel-bearing ore from the Harriman area near Rockport, Maine. The samples were taken by Roland F. Beers, Inc., for tests in cooperation with the Federal Bureau of Mines. One sample, analyzing 0.38 percent copper and 0.71 percent nickel, was essentially a disseminated pyrrhotite in hypersthene. Pentlandite, chalcopyrite, pyrite, and millerite were intimately associated with the pyrrhotite. Locked series flotation tests on this sample showed that 87.4 and 73.4 percent of the copper and nickel, respectively, could be recovered in a bulk concentrate that analyzed 3.47 percent copper and 5.34 percent nickel. The copper-and nickel-bearing minerals were collected with sulfhydric collectors in an alkaline circuit. Cleaning the concentrate three times with the addition of pH regulators was sufficient to attain the previously stated grades. The second sample had analyses of 0.31 percent copper and 0.85 percent nickel; talc and hypersthene were the main gangue minerals. Bulk sulfide flotation, made while depressing the talc, resulted in a concentrate that analyzed 2.33 percent copper and 4.70 percent nickel at recoveries of 70.0 and 54.4 percent, respectively. Flotation of the talc followed by bulk sulfide flotation resulted in a nickel content greater than 5 percent. A locked-series test showed that 60.7 percent of the copper and 73.7 percent of the nickel could be recovered at grades of 1.29 and 4.85 percent, respectively.

Jan 1, 1961

By Andrew D. O. O’Brien, Linda J. McWilliams, Joe L. Howell, Douglas E. Pollock, Jeanne A. Zimmer, Andrew B. Cecala

A quick, safe, and effective method has been developed that allows workers to clean their dust laden work clothing periodically throughout the day. For the mining industry, this technique is much more effective than the current federally approved method of using a vacuuming system. This newly designed method is relatively inexpensive and can be easily installed at any operation to allow workers to clean their clothing without contaminating the worker, the work environment. or co-workers to elevated respirable dust levels. This clothes cleaning process uses an air spray manifold to blow dust from a worker's clothing in an enclosed booth, which combines the dust for capture and removal by a baghouse dust collector. Since the air exhausted by the dust collector causes the booth to be under negative pressure. no measurable quantities of dust were ever measure escaping from the booth to contaminate the work environment and/or other workers. The worker performing the cleaning process is required to wear a half-mask fit- tested respirator with an N 100 filter, hearing protection, and full seal goggles. Dust samples taken inside the respirator of test personnel performing the clothes cleaning process showed very minimal to no respirable dust. This clothes cleaning process was performed in less than 20 seconds and was significantly y cleaner than either the Federally approved method of vacuuming, or the most common method or using a single compressed air hose. It was also determined during this research that polyester-cotton blend coveralls clean more effectively than coveralls which are 100 percent cotton. The newly designed clothes cleaning process has potential application to any industry where workers' clothing becomes contaminated with most any type of dust or product.

The Technical Study Panel on the Utilization of Belt Air and the Composition and Fire Retardant Properties of Belt Materials in Underground Coal Mining (hereafter referred to as the Panel or the TSP) was established by Section 11 of the Mine Improvement and New Emergency Response Act of 2006 (MINER Act). The Panel was charged with providing “independent scientific and engineering review and recommendations with respect to the utilization of belt air and the composition and fire retardant properties of belt materials in underground coal mining.” The TSP was impaneled by the Honorable Elaine L. Chao and commenced its work on January 9, 2007. At this first meeting, Mr. Richard E. Stickler, Assistant Secretary of Labor for Mine Safety and Health, asked the Panel to report on many issues including how recent technological advances could be applied to atmospheric monitoring systems, point-type heat sensors, current state of fire-resistant vs. fireproof belt materials, and belt fire suppression systems to improve miner safety. In addition, Mr. Stickler asked the Panel to review belt air velocity limitations. The Panel members attended 12 days of public meetings over a nine-month period. Three of the public meetings were scheduled for the Panel to hear from technical experts and those persons or organizations interested in providing input. The meetings were held in Coraopolis, Pennsylvania with emphasis on belt fires, belt maintenance, belt flammability and toxicity, ventilation, and escape issues; in Salt Lake City with emphasis on ground control and convergence issues; and in Birmingham with emphasis on fire detection, sensors and atmospheric monitoring systems. National Institute for Occupational Safety and Health (NIOSH) researchers, Mine Safety and Health Administration (MSHA) personnel, representatives of the major belt conveyor manufacturers and a representative of the National Mining Association provided discussions at the Coraopolis meeting. In Salt Lake City, Utah, MSHA district managers and ventilation specialists, a member of the Aracoma Mine No. 1 investigation team, a representative of the Bureau of Land Management, and industry and consulting representatives of the Utah Mining Association and the Colorado Mining Association made presentations. In Birmingham, Alabama, atmospheric monitoring system representatives, NIOSH researchers, representatives of coal mining companies, and UMWA workers from two Alabama mining companies made presentations. In addition, a staff member of The Center for Regulatory Effectiveness also presented comments to the Panel. In conjunction with the meetings in Salt Lake City and Birmingham, three-member subcommittees of the Technical Study Panel made field visits to the Skyline Mine, the Aberdeen Mine, and the Jim Walter Resources Mine No. 4. The mine visits were scheduled to see first-hand the mining conditions under which belt air was being utilized as an additional source of intake air for working sections.

By M. O. Magnuson

This publication describes abandoned-mine fire-control work administered by the Bureau of Mines under cooperative agreements with State and local governments. The work was done by private contractors under the supervision of Bureau engineers. The work is authorized by Public Law 738, approved August 31, 1954, and Public Law 89-4, approved March 9, 1965. Earlier work was authorized by Interior Department Appropriations Acts for fiscal years 1949-55. A total of 70 fires have been controlled under this program in the eastern bituminous region. The nature and extent of the abandoned-mine fire problem in the bituminous region is discussed, and the methods used for controlling these fires are described. The methods that have been used, either singly or in combination, include loading out and cooling the burning material, installing fire barriers, surface sealing, and water and pneumatic flushing.

Jan 1, 1974

By Richard A. Winters

In 1987, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 334-acre Mountain Lakes Wilderness Study Area (OR-011-001) in order to evaluate its identified mineral resources. The study area is located in Klamath County about 15 miles northwest of Klamath Falls, Oregon, and is adjacent to the Mountain Lakes Wilderness. The area is underlain by Pliocene-age basaltic andesite. No mining districts are in the study area nor were any claims recorded or found. There are no oil and gas lease applications. There are no identified mineral resources in the study area. INTRODUCTION This report describes the USBM (U.S. Bureau of Mines) portion of a cooperative study with the USGS (U.S. Geological Survey) to evaluate mineral resources and potential of the Mountain Lakes WSA (Wilderness Study Area), at the request of the BLM (U.S. Bureau of Land Management). The USBM examines individual mines, prospects, claims, and mineralized zones, and evaluates identified mineral and energy resources. The USGS evaluates potential for undiscovered resources based on areal geological, geochemical, and geophysical surveys. Results of the investigations will be used to help determine the suitability of the WSA for inclusion into the National Wilderness Preservation System. Although the immediate goal of this and other USBM mineral surveys is to provide data for the President, Congress, government agencies, and the public for land-use decisions, the long-term objective is to ensure the Nation has an adequate and dependable supply of minerals at reasonable cost.

Jan 1, 1988

The first metal-mine accident-prevention course was prepared and published in 1942-45 as a series of seven miners' circulars (Nos. 51-57). The scope of the course has been broadened, revised, and brought up to date and is being published as a similar series of seven miners' circulars (Nos. 51-57, revised) on accident prevention in metal and nonmetallic mines. These circulars are: Accident Statistics (Miners' Circular 51), dealing with general statistics on accidents and injuries at metal and nonmetallic mines, including causes, costs, and the use of investigations and reports of all accidents.

Jan 1, 1957

By V. A. Danielson

The Bureau of Mines studied waste disposal methods a1 a coal mine in Kentucky and another in Alabama to develop cost estimates, to provide better knowledge of current practices, and to guide consideration of alternate disposal methods. Costs of the existing waste disposal systems at each mine were estimated using present-day costs of equipment and labor. Costs of waste disposal systems using alternate equipment were also estimated. Although total disposal costs were essentially the same for both operations, reclamation costs will differ because of different reclamation practices.

Jan 1, 1969

By Bernard Lewis

During the past 10 years the technical investigations conducted by the Explosives Division of the Mine and Explosives Bureau of the Bureau of Mines have been described in a series of summarizing reports prepared by Wilbur I. Huff, consulting explosives chemist of the Bureau. These reports covered the…

Dec 1, 1947

By W. T. Abel

The difficulties associated with wet-processing fine size coal led the Bureau of Mines to investigate a dry process for removing pyrite from coal pulverized to powerplant fineness. The dry process that was investigated consists of two cleaning steps: First, centrifugal separation is used to remove a fine, pyrite-depleted portion as a product; second, the remaining coarser, pyrite-enriched portion is taken to electrostatic separation in which pyrite is concentrated and rejected. Ball milling and Hardgrove milling were used to pulverize the coal. Three coals from the Pittsburgh seam were treated by the dry-removal process. Over 55 pct of the pyrite, which amounted to 70 pct of the available pyrite, was removed in a reject of 10 to 20 pct from one of the coals. Similar treatment of the other two coals removed about 35 to 50 pct of the pyritic sulfur, which amounted to about 70 pct of the available pyritie, sulfur from these coals. Both centrifugal and electrostatic separations were more efficient when pyrite particles were as large as possible. Separation efficiency was improved by confining the particle size of the feed to a relatively narrow range and by avoiding excessive amounts (more than 10 pct) of dust in the electrostatic range. The removal efficiency was increased with the use of stage grinding.

Jan 1, 1973

By Lloyd Williams

1. Reserves have been estimated for three coal beds in Bledsoe County, Tenn.: Morgan Springs, Lantana, and Sewanee. The Richland and Nelson beds occur in Bledsoe County also, but there was not enough information on them for making an estimate of reserves. 2. Known measured and indicated reserves for all beds, based on a minimum thickness of 14 inches and on 1,800 short tons per acre-foot of coal in place, are estimated at 43 million tons as of January 1, 1954. Of this total, 22 million tons represents coal 28 inches and more thick. Areas in the beds were omitted from the estimate because available data relative to the bed characteristics were insufficient for making an estimate conforming with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves deter-mined by this investigation.

Jan 1, 1956