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By M. A. Trevits, J. E. Urosek, A. C. Smith, M. P. Valoski

The National Institute for Occupational Safety and Health (NIOSH), in partnership with the Mine Safety and Health Administration (MSHA), is conducting research to test, evaluate, improve or modify coal mine fire-fighting strategies and methodologies through large-scale tests. Since wood is the second most abundant fuel available during a coal mine fire, it was decided that series of large-scale wood crib fire tests were needed to measure the products of combustion and to observe the capability of commonly available direct application fire suppression equipment, namely, fire extinguishers, water and gas-enhanced foam. This paper discusses the wood crib fire tests, provides insight into the products of combustion and describes observations made during the application of the fire suppression agents.

By Pamplinm J. W.

"INTRODUCTION For the past six years the United States Bureau of Mines in cooperation with the University of Alabama, Tuscaloosa, Ala., the Missouri School of Mines and Metallurgy, Rolla, Mo., and certain operating companies of the Florida land-pebble phosphate district have conducted an investigation to determine the amenability of phosphatic sands to concentration. 4 This paper discusses briefly an investigation of the concentration of fine phosphatic sanads of the land-pebble district of Florida. The process used - namely, the tabling of material previously given a selective oiling treatment - is new in its application to the phosphate industry, although old in principle.The feed to the standard phospidate washery is a hydraulically wined mixture of phosphate pebbles, quartz sand, and clay in which the quartz sand grains are segregated in the fine sizes. Me standard method of concentrating (washing) consists of wet-screening. at about 20 mesh to recover the plus 20-mesh material. 5 Lately some of the washeries have introduced hydraulic classifiers for sizing of the screen undersize to recover the coarser spigot products, but even this additional treatment allows much of the fine phosphate to be wasted."

Dec 1, 1932

By D. Harrington

This circular presents part I of a series of papers of a review of the literature on air conditioning in mines, with particular reference to the health, safety, and efficiency of miners. It deals with the physiological aspects of exposure to air contaminated by organic matter, noxious and toxic gases, and dusts that emanate from various sources in underground workings; part II will discuss the relation of abnormal mine temperatures and humidities to the health and efficiency of minors; and part III will describe theoretical and practical methods of air conditioning mines to correct or alleviate the conditions mentioned and will discuss the results attained by some of the systems now in use in various parts or the world.

Jan 1, 1938

By Raymond W. Hiteshue

Experiments were conducted al temperatures of 480° to 800° C. and hydrogen pressure of 6,000 p.s.i.g. to determine the effect of coal residence time on the conversion of a high-volatile bituminous C coal to liquid and gaseous products when using a semicontinuous apparatus designed fur rapid heating and cooling of reactants. The objective of the studies at high temperatures was to determine if appreciable quantities of coal could be converted to gaseous hydrocarbons and low-boiling liquid hydrocarbons. Experiments at lower temperatures were designed to indicate shifts in product distribution with respect to temperature and to learn more about the general mechanism of the reaction when using close control of coal residence time. One percent molybdenum, based on m.a.f. (moisture-and ash-free) coal, was used throughout this investigation. At 800° C., 6,000 p.s.i.g., and "zero" residence time) the yield of gaseous hydrocarbons was about 38 percent and the yield of oil about 4.5 percent, based on m.a.f. coal. With IS minutes residence time, under the same conditions, the yield of gaseous hydrocarbons was approximately 80 percent with no increase in yield of oil. Apparently at 800° C., and hydrogen pressure of 6,000 p.s.i.g. coal was rapidly carbonized to char with expulsion of volatiles. Char was then slowly hydrogenated to gaseous hydrocarbons without production of oil.

Jan 1, 1962

By Sidney Katell

This report covers the period January 1962 through December 1962; it is a continuation of the series that began with the publication of Information Circular 7510 in October 1949. Also, it is the fourth in a series of reports prepared under a cooperative agreement between the Bureau of Mines and the American Association of Cost Engineers. The agreement provides for the publication of an annual cost bibliography with the work load evolved in the preparation shared equally. The abstracted articles, concerned with all facets of cost engineering in the field of chemical and petroleum plants and related subjects, are from tile following sources: 1. American Association of Cost Engineers Bulletin. 2. Bureau of Mines Information Circulars. 3. Bureau of Mines Reports of Investigations. 4. Chemical Engineering. 5. Chemical Engineering Progress. 6. Chemical Week. 7. Coal Age. 8. Coal Utilization. 9. Cost Engineering. 10. Hydrocarbon Processing and Petroleum Refiner. 11. Industrial and Engineering Chemistry. 12. Nucleonics. 13. Oil and Gas Journal. 14. Petroleum Management. 15. World Oil.

Jan 1, 1963

By Russell Levens

A strategy for prioritizing mining health and safety research by evaluating the potential for risk reduction through interventions is proposed. Mining has one of the highest incidence rates of injury and disease found in major industries. The main premise of this paper is that often the best opportunities to reduce these rates are not revealed by retrospective analysis of injury and illness data. Instead, a proactive approach is needed that accounts for risks to specific hazards that can be abated by engineering or behavioral interventions. The process proposed here begins with development of prospective interventions. The degree of reduction in risk to be expected from an intervention then is determined from statistics on the mining worker population, the expected degree of success of the intervention, and the expected change in the severity of injuries resulting from the intervention. Three disparate mining health and safety concerns are presented to demonstrate common problems in assessing risks of injury and illness and describe additional data needs. Information on events preceding injuries and illnesses and more detailed demographic data on the mining work force are needed to analyze injury and illness data more precisely. Detailed information on exposure to specific hazards is necessary to evaluate the potential for an intervention to reduce risk of injury or illness.

By Lynn Alcorn, Jeffrey Shawn Peterson

Data collected by the Mine Safety and Health Administration (MSHA) has shown that roof bolting machine (RBM) operators are the second most likely type of underground mining machine operator to be are over exposed to noise, per the MSHA Permissible Exposure Limit. In response to this, the Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) has initiated a project to develop engineering noise controls for roof bolting machines. Key to this research is an evaluation of the duty cycle of a typical roof bolting machine operation and this paper presents the results of such an exercise for data collected at two cooperating coalmines. The evaluation entails a time motion study of an operators' shift, logging each activity for time (e.g., tramming the machine, drilling holes, installing the roof bolt, etc.) and the noise levels associated with each task with a Larson Davis Spark 705+ dosimeter. NIOSH post processed the data to determine which tasks the operator devotes the most time to and the noise dosage accumulated during those tasks. These results provide insight into which portion of the operators' duty cycle is the most prominent contributor to noise exposure and thus, where research activities for the development of engineering noise controls should be focused. It was determined that the task of drilling holes is the most significant source of the operators' noise exposure and project research has focused on engineering noise controls to reduce the noise emissions generated during the drilling portion of the machine duty cycle.

By Bruce F. Grant

"INTRODUCTION The future of oil production in the part of the Appalachian region included in southwestern Pennsylvania; West Virginia, and southeastern Ohio is directly dependent on the maintenance of existing wells. This report presents an analytical study of the methods used in oil-well reconditioning in this area. The study is part of a research program designed to evaluate those means of stimulating oil production that can effectively and economically maintain present oil-production rates and make it possible to keep existing wells in operation. Well-reconditioning work was curtailed during the war; therefore, an abnormally large number of wells in the Appalachian Region is now in need of repair. Because the lubricant content of Appalachian crude: oils is high and the refined lubricating oils an; particularly suited to use in high speed, high-temperature engines, the demand for these crude oils during the war exceeds, the maximum rate of production obtainable under wartime operating conditions. Increases in operating, expenses, inability to meet war-time reconditioning costs, and inflexible price structures caused the abandonment of an alarming number of wells during the past 4 or 5 years.As a means of increasing regional oil-production rates, new drilling in the older fields for primary production generally is uneconomical because reservoir pressures in most of the fields have virtually been depleted and the production rates of newly drilled wells are small."

Feb 1, 1948

By Rimas Pakalnis, Doug Milne, Marc Ruest, Lewis Martin

Whereas many researchers and mine engineers have conducted tests on cable bolts using various grouts, water: cement ratios, and physical modifications of the cable to determine the load-carrying characteristics ofa bolt, few studies have been conducted on cable bolts fitted with internal instruments. Those studies that have been done have concentrated on cable response averaged over significant (6.1 m) cable lengths. Researchers at the Spokane Research Laboratory (SRL) of the National Institute for Occupational Safety and Health in Spokane, WA, are investigating the physical properties of cable bolts by replacing the conventional king wire with a modified king wire on which strain gauges have been installed. A numerical analysis was performed to match laboratory results. Loads calculated by the model were then compared to loads measured in the laboratory on 1.83-m-long cables grouted into two 0.91-m-long pull-tube assemblies. Load along the cable was monitored with 20 strain gauges installed along the length of the cable. This paper documents test results on these modified cable bolts. The instrumented cable bolt provided reproducible point measurements of cable load as opposed to load measurements averaged over long cable lengths. Such point measurements can assist in interpreting the influence of cable confinement, grout quality, rock mass stiffness, and other factors. The instrumented cable bolt is a practical field and research tool because it can predict point loading along the cable. The instrument has been successfully field tested at FMC's Granger Mine, Granger, WY; the Meikle Mine, Carlin, NV; the Stillwater Mine, Nye, MT; and the Getchell Mine, Golconda, NV. By monitoring load and displacement of the rock mass using these instrumented bolts, more-effective ground support can be selected and installed, which will lead to safer working conditions for miners.

Jan 4, 2004

By L. Nahai

An important objective of the Australian Government's policies on resources development is to encourage further processing of raw materials domestically, to the extent that this is economically feasible and consistent with sound industrial development. This Bureau of Mines report examines the extent to which Australia is able to pursue this policy in terms of its own competitive advantages and the implications of such a policy for the United States. Such factors as the impact of other competing producers and their advantages, expected world demand, and infrastructural problem--which may limit pursuit of this policy to the fullest extent--are discussed. After a broad review of the re-source, economic, social, and environmental factors, the perspective for increased processing is examined for a number of mineral commodities.

Jan 1, 1982

By Rudy J. Matetic

Over-exposure to noise remains a widespread and serious health hazard in the U.S. mining industries despite 25 years of regulation. Every day, 80% of the nation’s miners go to work in an environment where the time weighted average (TWA) noise level exceeds 85 dBA and more than 25% of the miners are exposed to a TWA noise level that exceeds 90 dBA, the permissible exposure limit (PEL). Additionally, MSHA coal noise sample data collected from 2000 to 2002 show that 65% of the equipment whose operators exceeded 100% noise dosage comprise only seven different types of machines; auger miners, bulldozers, continuous miners, front end loaders, roof bolters, shuttle cars (electric), and trucks. In addition, the MSHA data indicate that the roof bolter is third among all the equipment and second among equipment in underground coal whose operators exceed 100% dosage. A research program was implemented to: 1) determine, characterize and to measure sound power levels radiated by a roof bolting machine during differing drilling configurations (thrust, rotational speed, penetration rate, etc.) and utilizing differing types of drilling methods in high compressive strength rock media (>20,000 psi). The research approach characterized the sound power level results from laboratory testing and provided the mining industry with empirical data relative to utilizing differing noise control technologies (drilling configurations and types of drilling methods) in reducing sound power level emissions on a roof bolting machine; 2) distinguish and correlate the empirical data into one, statistically valid, equation, in which, provided the mining industry with a tool to predict overall sound power levels of a roof bolting machine given any type of drilling configuration and drilling method utilized in industry; 3) provided the mining industry with several approaches to predict or determine sound pressure levels in an underground coal mine utilizing laboratory test results from a roof bolting machine and 4) described a method for determining an operators’ noise dosage of a roof bolting machine utilizing predicted or determined sound pressure levels.

Jan 1, 2006

By S. J. Anderson

To deftne the capabilities of a nonexplosive excavation concept, the Bureau of Mines conducted reduced-scale laboratory tests of a mechanical excavation tool called a rock splitter. The splitter investigated was capable of applying combinations of radial and axial loads to rock when placed in a predrilled hole. Experiments conducted with the tool in concrete, limestone, and granite proved it capable of excavating all three materials. Break geometry in these three materials was the same, which encourages the prediction of performance in all rocks. The design of the radial-axial loading splitter's feather components significantly affected the tool's performance. It appears the design of this in-hole component should be tailored for the rock to be excavated.

Jan 1, 1987

By Sidney Katell

This report covers the period January 1962 through December 1962; it is a continuation of the series that began with the publication of Information Circular 7516 in October 1949. Also, it is the fourth in a series of reports prepared under a cooperative agreement between the Bureau of Mines and the American Association of Cost Engineers. The agreement provides for the publication of an annual cost bibliography with the work load evolved in the preparation shared equally. Tile abstracted articles, concerned with all facets of cost engineering in the field of chemical and petroleum plants and related subjects, are from tile following sources:

Jan 1, 1963

By W. W. Adams

"The ninth yearly National Safety Competition covering the calendar year 1933, conducted by the United States Bureau of Mines, w participated in by 332 mines and quarries situated in 35 States. Enrollment represented as increase of 10 plants over 1932, and one addition was made to the number of States represented.The primary purpose of the United. States Bureau of Mines in conducting the contest is to promote safety in United States mineral industries. This purpose is accomplished directly through the efforts of the competing companies and their employees to win first place in the competition and thereupon receive recognition on a national scale for their achievement the purpose is accomplished indirectly through studies by the United States Bureau of Mines of the facts contained in the accident reports the competing companies furnish to enable the Bureau to compute the accident rates that are the basis for determining the winners of the contest.The statistics which constitute the basis for determining the winning companies and the relative standing of all companies are prepared uniformly without regard to the States in which the companies operate, or to differences in classes of accidents covered by State laws relating to compensation for injuries resulting, from industrial accidents.Bronze trophies, known as 'Sentinels of Safety', which were provided by The Explosives Engineer magazine to be awarded annually by the Bureau of Mines, were presented to five companies in the contest of 1933, each company having established the best accident-prevention record within one of the five classes into which all companies were divided, namely, anthracite-mining companies, bituminous-coal-mining companies, metal-mining companies, operators of nonmetallic-mineral mines other than coal mines, and quarries or opencut mines. The trophies are awarded for 1 year and are then transferred to the winners of the succeeding year's contest.The trophy for bituincus-coal mines was won by a company in Wyoming. A company in Tennessee won the trophy for metal mining. In the nonmetal-mine group the trophy was again won by a company in New York. A quarry in Michigan won the trophy for the quarry-and-opencut-mine group. The trophy for anthracite mines remains in Pennsylvania, as all anthracite mines in the contest are in that State."

Jul 1, 1934

By V. A. Cammarota

In this report, the effects of anode-production variables, such as aggregate coke sizes, pitch binder content, and baking cycle, were investigated. A small alumina reduction cell proved effective in evaluating anodes prepared from commercial materials and from lignite coke and pitch. Compressive strength was found to be the physical property most significantly influenced, but it did not appear to affect anode consumption. Specific carbon consumption, that is, the ratio of carbon in the anodic gas to carbon theoretically oxidized at the anode, was used as an index of anode consumption. It was found that an anode made with lignite coke and commercial pitch was very low in consumption; however, anodes made completely from lignite but by a different fabrication method showed high consumption and anode deterioration. Microscopic examination of anodes after electrolysis showed evidence of higher consumption at low current densities, and was useful in judging overall anode quality. Based on the physical properties of the anodes and their consumption during electrolysis, lignite can be a suitable material for anodes, provided the proper fabrication conditions are used.

Jan 1, 1970

By Robert E. Johnson

1962 was the second year of recovery from the mild 1960-61 recession. The year-to-year gain in constant dollar gross national product, our most comprehensive measure of the country's economic performance, was 6.0 percent (from $447.7 billion in 1961 to $474.8 billion in 1962). The unemployment rate declined from 6.7 percent to 5.6 percent. Although it was a good year, there were still unused resources of labor and capital which implied that the economy was operating below its potential. The year-to-year change in the Federal Reserve Board (FRB) index of industrial production of 7.6 percent masked the fact that more than one-third of the growth took place within 196L The monthly index rose only 4.8 percent during 1962, from 114.3 in January to 117.8 in September. The fact that the economy as shown by the industrial index, rose rapidly in the first half of the year only to remain on a plateau of 119-120 during the second half, led some people to fear an imminent downward turn. This did not occur. Neither production nor consumption of mineral fuels advanced as fast as the total economy. But consumption showed more gain than production, 5 percent compared with somewhat less than 4 percent. Production of both crude oil and natural gas reached new highs while bituminous coal production was the highest in 5 years.

Jan 1, 1963

This article updates the status of fatalities occurring in both coal and metal/nonmetal mines from January through December of 2001. Based on preliminary accident reports, as of December 31, 2001, seventy-two fatalities have occurred at coal and metal/ nonmetal mining operations. During this period, forty-two fatalities occurred at coal operations and thirty fatalities occurred at metal/nonmetal operations. Ignition or explosion of gas or dust and fall of roof were the most frequent accident classifications in coal and powered haulage fatalities were the most frequent accident classification in metal/nonmetal.

Jan 1, 2002

By K. E. Robinson

Appendix A is an abridged extract of the report prepared by the Geotechnical and Structural Engineering Society of Idaho, and presents the results of their one-year study to evaluate the feasibility of disposing mill tailings by landfill construction. Appendix B describes the field and laboratory testing program completed by RDM to assess the effectiveness of a soil (slimes) liner as a means of seepage control to reduce the introduction of contaminants into the local ground water regime. Appendix C presents a summary of a thesis by Lawrence Martin on the analysis of the acid production potential of mill tailings, and the results of geotechnical testing of mill tailings completed by ROM. Appendix D describes potential landfill sites identified within the study area, the development of these sites to meet the present needs of the mining industry and the future requirements of the community is described. Appendix E summarizes the main legislation impacting on tailings disposal. Appendix F discusses the environmental and socio-economic factors that should be considered.

Jan 1, 1981

By J. M. Davidson

The potassium mineral polyhalite (K2SO4.MgSO4.2CaSO4.2H20) found in large deposits in western Texas and southeastern New Mexico is associated with varying amounts of halite (sodium chloride, NaCl) and anhydrite (calcium sulphate, CaSO4). Although the anhydrite, because of its low solubility and slow rate of solution, is relatively inert, the halite is dissolved immediately in any process solution with which the polyhalite comes in contact. Limited quantities of sodium chloride in the liquors used for the hot extraction of polyhalite materially improve the results obtained,4 but only a very small sodium chloride content may be desired in the entering polyhalite in other procedures, such as Bureau of Mines process 75. In. all of the processes suggested for the recovery of potassium sulphate from polyhalite the control of the sodium chloride content will be desirable, if not absolutely essential to efficient operation. OCCURRENCE OF HALITE IN POLYHALITE A preliminary estimate of the amount of halite associated with typical deposits of polyhalite may be derived from drill cores, although it should be remembered that only 50 or 60 core tests have been made in the many hundreds of square miles of the Permian basin. From a mineralogical study of 41 of these cores, Schaller and Henderson6 state: In many of the sections of core that seem when viewed by the unaided eye to consist essentially of polyhalite, both halite and anhydrite are present in greatly varying quantities - with very minor quantities of clay and magnesite.

Jan 1, 1934

By R. H. Bedford, F. T. Johnson

"In California the history of tin mining began in Riverside County in 1853, with the discovery of the Temescal deposit. This deposit remained the only one with a production record until recent small shipments were made from Kern and San Bernardino Counties.According to the California State Division of Mines, Temescal's total output has been about 125 tons of tin, all of which was produced in 1891 and 1892. It was idle from 1892 to 1928.An extensive but unsuccessful development campaign carried on in 1928 and 1929 by the American Tin Corp. produced only half a ton of the metal, and the property again was idle until 1943, when an attempt to resume operations proved unsuccessful. After 1929 no production is recorded from California until 1944 end 1945, when small shipments of sorted ore from Kern County returned about 2 tons of tin and 1-1/3 tons was recovered from sorted ore and concentrates from San Bernardino County. The total output of tin from California has been less than 150 tons, and less than 4 percent of this was produced in the last 50 years, in spite of numerous attempts during that period to promote tin mines,So marked a scarcity of a metal essential in war makes any occurrence interesting. When some prospects were reported to the Bureau of Mines in July 1942, in a new field 10 miles east of Gorman, they were at once examined and the preliminary exploration by the owners closely followed. Eventually one was explored by bulldozing end diamond drilling as a joint project by the Bureau of Mines and the Geological Survey.To supplement this joint project, the authors undertook independently a general survey of tin in California - a survey designed to check reported occurrences and to bring their status up to date. In this work, the 37 places described in the text and spotted on the accompanying map, (fig. 1) were visited end sampled. Although traces of tin were found in many pieces, nothing that suggested a tin mine was found anywhere, and it is difficult to base much hope for appreciable future tin production upon anything found thus far in California."

Apr 1, 1946