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By G. E. McClelland

As part of its mission to assure an adequate domestic supply of metals essential to the Nation's welfare, the U.S. Department of the Interior, Bureau of Mines, investigated a particle agglomeration technique as a means for improving the flow of leaching solution through heaps of clayey or finely crushed, low-grade, gold-silver ores. Bench-and pilot-scale experiments showed that the percolation rate of cyanide leaching solution was markedly enhanced by mixing the ore with a portland cement binder, moistening the mixture, and mechanically agglomerating and aging the feed prior to heap building and leaching. The rate of gold and silver recovery markedly increased because of the increased, uniform percolation of leaching solution through the agglomerated feed. The use of concentrated cyanide solution instead of water during the agglomeration procedure decreased the leaching time required to obtain maximum recovery. Results of bench-and pilot-scale experiments are discussed.

Jan 1, 1981

By Lisa Steiner, Robin Burgess-Limerick

In 2004, underground coal mines in the United States reported 3,405 injuries to the U.S. Mine Safety and Health Administration (MSHA). Of these, 17 percent were associated with the use of bolting machines, 8 percent with continuous miners, and 4 percent each with scoop/load-haul-dump (LHD), shuttle cars and personnel transport. Analysis of the injury narratives identified five hazards that required attention. They are rock falling from supported roof inadvertent or incorrect operation of bolting machine controls, handling continuous miner cable, collisions while driving underground vehicles and driving or traveling in underground vehicles on rough roadways. The rate of lost-time injuries has steadily decreased during the past 10 years (from more than 10 per 100 FTE in 1995, to six in 2004). However, underground coal mining remains a hazardous industry. One of the contributors to this elevated injury risk is working with or near underground coal mining equipment. Roof bolting machines and continuous miners have been consistently identified as high risk equipment. They account for approximately 24 percent of all injuries to underground coal miners (Sanders and Shaw, 1989). LHD's, shuttle cars and personnel transports are also associated with injuries in underground coal mines (Burgess-Limerick, 2005). Conventional analyses of injury statistics typically provide tables detailing the breakdown of injuries by body part nature of injury or mechanism of injury. Such analyses are worthwhile and may be helpful in tracking broad trends over time. Further information is available in the narrative text field completed for each injury reported. The detail contained in these narratives varies. However, they generally provide some insight into the causes of the injury, such as the activity being performed at the tune of

Create two air splits along the longwall face to isolate the shearer-generated dust to the immediate face area, maintaining a cleaner split of air in the workers' walkway.

Jan 1, 1994

By S. P. Howell, M. W. Von Bernewitz

"Introduction. The first short—flame explosives were made in the United States during the year 1902, then the mount was 11,300 pounds. In 1902 they were designated ""permissible explosives"", and were required to meet specific tests. By 1912 the total consumption thereof had increased to 24,630,000 pounds, equal to 5 per cent of the total quantity of all kinds of explosives produced in this country; while in 1922 the total was 43,429,000 Pounds, or 10 per cent of the production, and 18 per cent of the explosives used for the mining of coal.Each year the Bureau compiles statistics of explosives, one important object of this being to show the extent to which permissible explosives are replacing other classes of explosives in coal—mining operations, and the influence of such replacement in reducing the number of accidents caused by explosives in this class of mines. The consumption of permissible since 1916 has considerably exceeded the quantity of high explosives (dynamites, etc.) used in coal mines. While the increase in use of permissible is good, the replacement of other explosives therewith is not nearly as good as with be, considering the known general efficacy and safety of permissibles."

Mar 1, 1924

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 George H. Johnson

An evaluation of the diamond-bit-performance data accumulated from core-drilling cherty limestone and cherty dolomite reveals that the percentage of core recovered and the physical characteristics of the bits and diamonds used are economically significant. One of the established trends, of particular interest to those engaged in diamond drilling, is that bits set with small, low-quality, West African drill bort are the most economical. Detailed analysis of the factors that affect diamond-bit performances, such as diamond size and quality, bit size and type, percentage of core recovered, and the physical characteristics of the bit matrices are assessed in the tables, charts, and discussion.

Jan 1, 1958

By T. C. Higgins, J. S. Malesky, J. A. O'Connor

"INTRODUCTION This circular contains the story of a stubborn mine fire of electrical origin that started on the main haulage road of No. 59 mine of the Peabody Coal Co. and illustrates that sometimes serious fires can be fought by direct attack. The story also points out that the cost of such procedure can be extremely high, and it is better, therefore, to minimize the possibility of a fire of electrical origin by suitable over-current and line-fault protection. The lives of 163 men were saved by utilizing a recently sunk air shaft near active workings as an escapeway. These men could not have reached the older openings. Also described are the rescue of 75 additional men through another air shaft, sealing of the fire, attempted extin¬guishment with carbon dioxide, and the difficulties of fighting the fire and recovering the mine.A fire occurred shortly before 12 o'clock noon, August 15, 1949, in the No. 59 mine, Peabody Coal Co., Springfield, Ill. All 257 men underground escaped to the surface. One group of 75 men was delayed from escaping for several hours after the alarm was given because smoke and fire gases were circulating in a main return airway, which intervened between their working section and one air shaft, and also in the stairway compartment of the shaft. After being supplied with universal-type gas masks, or self-rescuers, these men were conducted from the mine by members of a State mine-rescue team and other mine employees. Six nine officials were hospitalized because of exposure to carbon monoxide during fire-fighting activities; all were discharged a few days afterward. Later, while doing work incident to fighting the fire, two men were killed, and several were injured by falls of roof and rib.The fire broke out after a collision of a loaded trip with four empty mine cars on the main east haulage entry. The mine cars were jammed against the trolley wire causing a sustained electric arc that ignited the wooden mine cars and the fire spread to the timbers and coal."

Apr 1, 1950

By Oliver Bowels

Many inquiries are received by the United States Bureau of Mines for the names of elementary books on geology, mineralogy, methods of identifying minerals, prospecting, and similar subjects. In response to this demand the following brief bibliography has been prepared. As many of the inquiries are received from those who have limited technical knowledge of the subjects involved, the bibliography includes the simpler texts which present the subjects in nontechnical language. Other texts contain glossaries which define the technical terms used. A short note following the title indicates the character of each book, the number of pages, and the price. Thus, elementary mineralogists or geologists, prospectors, mineral collectors, nature students, or travellers may select the texts that best suit their requirements and their capabilities. To supply the needs of more advanced students, quite a number of the standard texts used in schools and colleges are included in a second group. A short list of books on economic geology and mineralogy has also been added.

Jan 1, 1929

To reduce equipment operator exposure to respirable dust in enclosed cabs by examining the effectiveness of retrofitting air pressurization and filtration systems on existing cabs.

Jan 1, 2001

By R. V. Ramani, A. S. C. Owili-eger

This report was prepared by The Pennsylvania State University under USBM Contract No. G0111808. The contract was initiated under the Coal Mine Health and Safety Program. It was administered under the technical direction of DMSE, with Mr. G. R. Schottler acting as the technical project officer. Mr. J. A. Herickes was the contract administrator for the Bureau of Mines. This report is a summary of the work recently completed as part of this contract during the period June, 1971 to December, 1973. This report was submitted by the authors on March 31, 1974. Part of the research reported here was originally done on a grant from the Department of Environmental Resources, Commonwealth of Pennsylvania and reported in Special Research Report No. SR-95 (February 25, 1973) of the Coal Research Board, The Pennsylvania State University.

Jan 1, 1974

By Robert C. Hickman

"INTRODUCTION The Big Four fault and the Sandy Creek fault, with several cross faults, traverse the Stalion-Curnel fluorspar prospect in a northeasterly direction. The Big Four mine, about three-quarters of a mile northeast of the prospect, is the only active mine in the immediate area.A resistivity survey was made of a portion of the prospect by the Division of Geophysical Exploration, Bureau of Mines, in May and June 1946. As a result of this survey, five holes were drilled by the Bureau of Mines during the period from October 8 to December 16, 1946. Two Longyear No. 12 Junior Straitline diamond drills were used for the work.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Division, Lowell B. Moon, chief, conducts preliminary examinations, does the actual investigative work, and prepares the final report. The Metallurgical Division, Oliver C. Ralston, chief, analyzes samples and makes beneficiation tests.The project was under the supervision of Mitchell H. Kline, chief, Raleigh Branch, Mining Division."

Mar 1, 1948

By Berenice B. Mitchell

THE STATISTICAL tables in this chapter present, country by country, the mineral production of the world in 1949-50. The figures are on a mine basis, unless otherwise indicated, except for cement, coke, and steel, which are measured at the processing plant. The tables are essentially a retabulation, by countries, of the 53 commodity world tables appearing in the various chapters of this volume. For lack of comprehensive information, data for the following minerals are excluded: Andalusite, aplite, asphalt, boron, bromine, calcite (optical), calcium chloride (natural), carbon dioxide, clay, columbium (niobium), diatomite (kieselguhr), dumortierite, emery, garnet (abrasive), gem stones (other than diamonds), germanium, greensand, grindstones, helium, indium, iodine, kyanite, lithium, magnesium compounds (other than magnesite), meerschaum, mineral pigments, monazite, natural gas, natural gasoline, oil shale, olivine, perlite, pumice, quartz crystal, radium, sand and gravel, selenium, sillimanite, sodium salts (other than common salt), stone, strontium, sulfur (byproduct), tantalum, tellurium, thallium, topaz (industrial), tripoli) uranium, vermiculite, wollastonite, and zirconium. In addition, a few minor geographic areas for which no statistics are available, are also omitted from the tabulation; it is believed that no significant quantities of minerals are mined in any of these areas. The statistics in these tables were derived principally from questionnaires sent, in cooperation with the United States Department of State, to the governments of each country. Supplementary sources were United States consular reports, the Imperial Institute's Statistical Summary of the Mineral Industry of the British Commonwealth and Foreign Countries, other official publications of various countries, the United Nations Statistical Yearbook, the Year Book of the American Bureau of Metal Statistics, Minerais et Metaux, business magazines, and company reports. Where official data were not available, esti-

Jan 1, 1953

ESTABLISHMENT of an effective inspection system has been held essen¬tial to any international agreement that may be designed primarily to curb the testing of nuclear weapons. A number of reports and papers already have described basic inspection concepts and appraised various pro¬cedures, techniques, and methods as to their probable effectiveness in detecting and identifying violations under such agreement. This report results from a study of only one part of the contemplated inspection system, specifically the final phases embracing onsite investigations and mine examination techniques. The results and reports of earlier work were reviewed in detail, and subjects that were found to have been exhaus¬tively evaluated are recognized by reference and not redescribed here. In other instances, previously described techniques, methods, and clues were revaluated to define more clearly their practical value to the final objective of an onsite inspection. Previous documentation does not refer to a number of subjects, techniques, tools, clues, and methods considered by the study; this report treats these in detail, even though when applied singly or collectively their practical value may be questionable.

Jan 1, 1962

By D. C. Fleck

The Bureau of Mines, in a cooperative research program with four lead companies, has investigated ferric chloride leaching of galena to prepare lead chloride for molten-salt electrowinning to produce lead metal. The hydrometallurgical-electrolytic process is an alternative to the sintering-smelting-refining process currently used to produce lead metal and avoids the environmental problems associated with a conventional smelter. During investigations on the electrowinning aspects of the work, it was noted that certain cations, moisture, and sulfate in the electrolyte affect lead metal purity, cell voltage, current efficiency, and viscosity of the electrolyte. Results of bench-scale tests are re-ported on the effects of CaCI2, CuCI2, FeCI2, MgCI2, NaCI, ZnCI2, PbS04, and moisture on electrolysis. As impurities increased in the electrolyte, current efficiency decreased. CaCI2, CuCI2, and FeC12 decreased current efficiency by 12 to 47 pct. ZnCl2 gave a small voltage increase, while CaCI2 addition equivalent to 4.9 pct Ca caused a 50-pet increase in voltage. The lead metal was contaminated in direct proportion to the CuCI2 buildup in the electrolyte, Anode corrosion was observed with MgCI2 and MgC12?6H20. Viscosity increased appreciably with the buildup of NaCI, CaCI2, and sulfate. Electrolyte foaming occurred with ZnC12, MgC12?6H20, MgC12, FeC12?2H20, and FeCI2. Moisture inhibited the coalescence of the lead metal.

Jan 1, 1983

By R. L. Montgomery

The literature has been surveyed and values recalculated for the heats and free energies of formation of solid rare-earth compounds at 298° K. In most instances it was necessary to estimate the entropies. Thermodynamic properties of aqueous rare-earth ions have also been calculated. INTRODUCTION The accumulation of thermochemical data on rare-earth compounds in recent years makes it possible to review the subject and to obtain more consistent and more reliable information than was available previously.

Jan 1, 1959

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 N. T. Lowe, R. E. Miller

When two pieces of heavy equipment interact, jolting and jarring can occur. During haulage truck loading for example, there is a chance that the operator of one or both pieces of the equipment will experience jolting and jarring. Additionally, a jolt can occur when an off highway equipment operator drives over a road defect or inadvertently strikes a berm. Aside from the operators, there is seldom anyone else that witnesses the interaction and can accurately describe the extent of the jolting. This makes it difficult for health and safety managers to address jolting and jarring. The devices and software described in this paper constitute a method for installing “black boxes” called Shox Boxes onboard equipment that already have a GPS system onboard. The resulting configuration provides an objective assessment of jolting and a chance to determine the root causes of it. The Shox Box system reviews data in real time, onboard the vehicles, 24 hrs a day, and sends pertinent information via radio to a central database. The data generated shows whether jolts are above or below a supervisor defined target value for the equipment and the tasks being performed. This allows health and safety personnel to demonstrate safe operation of heavy equipment and recommend proactive actions to maintain jolting within a reasonable range.

By Lawrence L. Davis

This chapter includes tables for 1981 that were not available in time for publication of the 1981 Minerals Yearbook, but does not include corresponding tables for 1982. The value of raw nonfuel minerals produced in the United States during 1982 was estimated at about $20 billion, a decrease of $5 billion compared with that of 1981. The decline in value is the first since 1971 and is the largest percentage drop since 1938. Although the domestic mining industry continued to be troubled by difficulties in attracting capital and by import competition from countries with lower overall production costs, the principal cause of the decline was sharply decreased demand brought on by the worldwide economic slowdown. Metal commodities were impacted most severely with only 4 of 21 metals registering production value gains and only 3 of 21 showing production quantity increases. Overall metal production value decreased 37% from that of 1981, a reflection of the domestic slowdown in the automobile and construction industries, which are major metal users, Overall production value of nonmetals decreased 12% compared with that of 1981, with only 14 out of 44 nonmetals showing increases. Nonmetal production quantities increased over 1981 for only 6 of the 44 nonmetals.

Jan 1, 1983

By Forrest T. Moyer

OVERALL data for 1963 on injury experience and the levels of employment, worktime, and operating activity of the mineral industries are shown in the statistical tables of this chapter. The general groupings of the industries are presented in greater detail in Volumes I and II of the Minerals Yearbook. A corresponding chapter in Volume I contains additional breakdowns of the data on metal, nonmetal, sand and gravel, slag, and stone mines and quarries together with separate information on the related processing mills and plants including primary nonferrous smelters. The more specific information on the anthracite and bituminous-coal, petroleum and natural gas, peat, and natural asphalt industries is given in the similar chapter of Volume II. Injury and employment data were collected from coal producers on the mandatory basis required by the Federal Coal Mine Safety Act (30 U.S.C., sec. 455). Producers of all other minerals (fuel and nonfuel) voluntarily reported the requested injury and employment data. The figures for 1963 are preliminary except for anthracite, coke, petroleum and natural gas, native asphalt, and slag which are final. Data for earlier years are final. The figures represent full coverage for all industries except the oil and gas industries for which coverage is not complete, particularly with respect to small companies.

Jan 1, 1964

By B. Dimitriades

Exploration of the photochemical reactivity of diesel-exhaust hydro-carbons is described. A smog chamber was built, and reactivities of diesel exhaust, gasoline exhaust, and propylene were measured at two chamber temperatures. Experimental data indicated the problems caused by instability of diesel-exhaust hydrocarbons. With reservations due to these problems, the results are interpreted to reflect comparable reactivities for diesel and gasoline exhaust.

Jan 1, 1971