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By George J. Conroy

This Bureau of Mines publication describes several fault locators and methods, including time domain reflectometers, a frequency domain reflectometer, tone generators, an infrared method, the Murray loop method, and high-voltage "click" methods. The Bureau of Mines has been conducting research into these methods for several years, to improve mine safety and facilitate production through rapid, safe location of trailing-cable faults. The problems encountered in practical applications are discussed, and schematic diagrams of several instruments fabricated by the Bureau are presented. Since no present single method of locating trailing-cable faults is universally applicable, a kit composed of several of the more promising fault locators is advisable.

Jan 1, 1978

By Earl L. Phillips

The Bureau of Mines conducted laboratory tests on samples of pozzolanic-cement concrete to develop a low-strength backfill. Results show that support costs can be lowered by replacing a portion of the portland cement in mine backfill with pozzolan (fly ash) and lime. Unconfined compression tests on various ratios of fly ash to cement in 84 samples produced compressive-strength curves that can be used to estimate the best backfill mix for any mine.

Jan 1, 1981

By W. A. Calhoun

The purpose of this investigation was to develop a procedure for removing excess iron from representative samples of bauxite ore from the Quapaw deposit of American Cyanamid Co., Saline County, Ark., in order to produce a beneficiated ore suitable for use in the alum industry, At the request of the sponsoring company, the samples were reduction-roasted at 800° C. and then magnetically separated. Although some rejection of iron was effected under these conditions, the general results were not satisfactory, A much more successful procedure, from the standpoints of both rejection of iron and recovery of alumina, consisted of a short (l5-minute), low-temperature (400° C.) oxidizing roast, followed by a 2-minute interval in a hydrogen atmosphere, then cooling to room temperature, and, finally, high-intensity magnetic separation to remove the iron.

Jan 1, 1957

By C. H. Elder, Maurice Deul

Coal degasification boreholes drilled from the surface have been success - fully hydraulically stimulated to increase the flow of gas from the coal. This Bureau of Mines report describes the hydraulic stimulation procedure for a coalbed, the equipment required, and design criteria for the treatment. Three examples of stimulation treatment show from fivefold to twentyfold increases in gas production. The tests were conducted in the Pocahontas No. 3coalbed, Buchanan County, Va., the Pittsburgh coalbed, Washington County, Pa., and the Mary Lee coalbed, Jefferson County, Ala. Two sites where the coal was hydraulically stimulated and exposed by subsequent mining show no adverse effect on mining operations through the treated zones. The induced vertical partings were confined to the coalbed and did not in any way affect either roof or floor rock.

Jan 1, 1975

By G. G. Morgis, J. J. Forbes

"INTRODUCTION The greatly diversified and increased uses of beryllium and its con& pounds in recent years have focused attention on the health hazards incident thereto. The Bureau of Mines has a fundamental interest in safety and the elimination or reduction of health hazards in the mineral and allied industries, and it recognizes that serious hazards are inherent in the production and use of beryllium and its compounds. This circular presents a review of the literature pertaining to such health hazards but does not describe original research by Bureau personnel. Most of the bibliography has boon either quoted in part or abstracted in an effort to present information in a comprehensive and readable form.In reviewing the literature, differences of opinions wore recognized in the writings of the respective authors, but no attempt was made to evaluate such differences. This presentation was devoted strictly to reporting without editorial comment.SUMMARYAlthough beryllium was known to industry for about 150 years, its toxicity did not present any serious problems in the United States until the advent of World War II, when the increased use of this element and its compounds brought to light several toxicologic reactions occurring primarily in the lungs and skin of workers handling it. The pulmonary effects, characterized as acute pnoumonitis and chronic pulmonary granulomatosis in beryllium workers, are far more serious than the dermatological manifestations.The addition of beryllium to the list of toxic industrial metals has boon so recent that there is still some confusion in the clinical picture. Data on magnitudes of exposure likely to be responsible for the production of disease are not yet adequate. There appears to be no relation between the severity of exposure and the development of cases some of those having had severe exposure have not developed a reaction, whereas those having a slight exposure in some instances have developed a response."

Jul 1, 1950

By J. F. Barkley

"In the course of the Government's Fuel Economy Survey of its own power plants, studies and tests have been made of various oil-burning equipments under power-plant boilers. There are now many types of burners being offered in the relatively limited field of power-plant use. The majority of the types used may be grouped into two general classes- those using steam to effect the atomizing of the oil, and those using mechanical means.Burners using steam have had the most prominence in this field for a long period. The mechanical atomizing type of burner successfully applied on shipboard, however, pointed to a possible betterment in land work. The vision presented itself of a burner that would need no steam for atomizing that would permit of air inlets or registers compactly arranged as a part of the entire burner, and that would only require the natural stack draft usually available in land boiler furnaces. Hence, rather recently there has been much development along this line, resulting in various types of burners.In Table 1 are grouped test items chosen from many tests showing representative analyses of the products of combustion obtained with various burners installed in various types of furnaces. In all these tests the burners were handled by experts and represent practically the best attainable for that particular arrangement. The boiler efficiencies ranged from 70% to 80%. It will be noted that the burners using steam for atomizing were able to secure slightly better 002 and less 02 without the presence of CO."

Feb 1, 1926

By G. E. McClelland

During the 1970?s, the Bureau of Mines investigated a particle agglomeration technique for improving the flow of leaching solution through heaps of clayey or crushed, low-grade gold-silver ores, wastes, and tailings. This technology has been adopted on a broad scale by the precious-metals-processing industry. This report presents information on five commercial operations that have benefited from agglomeration technology and that represent a cross section of current heap leaching practice. The technology is cost effective because of decreased leach times and improved precious metal recoveries.

Jan 1, 1983

Develop a safe, efficient filter for removing diesel particulate matter (soot) from the exhaust of underground mining machines equipped with water scrubbers. Approach The Bureau of Mines and the Donaldson Company, Inc., jointly developed a low-cost, disposable, pleated-media filter (PMF) system. The system is intended for use on Part 36 permissible equipment or other machines equipped with water scrubbers. The PMF is installed downstream of the water scrubber to take advantage of the cool exhaust produced by the water bath. This demonstration system was tested on three Jeffrey 4114 Ramcars and a Wagner LST-5 scoop at Utah Fuel Company's Skyline mine near Scofield, Utah. Figure 1 illustrates a clean filter element being inserted into the canister on the Ramcar. How It Works The PMF system consists of a water trap, an optional over-pressure relief valve, filter canister, and PMF Under normal operations exhaust from a vehicle equipped with a water scrubber is heavily laden with water, especially on immediate startup of the engine. The water trap is designed to remove most of the water droplets from the exhaust before they enter the PMF, thus improving PMF performance. The over-pressure valve is designed to limit the exhaust backpressure by venting off some exhaust gas before the: filter. It is attached to the water trap upstream of the PMF. Figure 2 illustrates and shows a break out sectional view of the location of the PMF on the Ramcar.

Jan 1, 1991

By Benjamin W. Haynes

The Bureau of Mines conducted research to devise technology for increasing the Nation's mineral supply by recovering valuable constituents from currently discarded waste materials. Municipal solid waste (MSW), presently a major disposal problem, represents a significant source of metals, glass, and a combustible fraction that can be used to supplement coal in generating heat and electricity. As part of the total metallurgical system to treat MSW, this study evaluates the combustible fraction of MSW to characterize the various combustible components and to identify the principal sources of elements that eventually may be objectionable from corrosive or environmental considerations. Several possible sources for cadmium, chromium, cobalt, copper, lead, nickel, and zinc have been tentatively identified. These sources are pigments, inks, paper stock, and additives to plastics. A correlation between industry consumption values and measured concentrations in MSW was found for several elements.

Jan 1, 1978

By J. E. Zeilinger

This Bureau of Mines report describes the preparation characteristics of the significant coalbeds of the Ohio coalfield. Washability analyses were made on 39 coalbed samples collected from a 14-county area. None of the samples were of metallurgical quality as received. Nine of the samples could be sufficiently upgraded to produce metallurgical-grade products, and the remaining 30 samples could not be upgraded to this quality because their sulfur contents could not be lowered to meet the standard. For steam or power generation, 10 of the samples were of medium sulfur content as received and one could be upgraded to a low sulfur content. Of the 29 samples having a high sulfur content as received, 18 could be upgraded to a medium sulfur content. The original sulfur content of the other 11 samples having a high sulfur content as received can be appreciably reduced by removal of the sink 1.58 specific gravity material; however, these coals would be classified as high sulfur coals both before and after removal of the sink 1.58 specific gravity material.

Jan 1, 1972

By D. B. Dow

The study of oil production methods with reference to the amount of oil originally pressent in the oil-bearing, formations has developed the fact that-ordinary methods-of production remove only a part of the oil actually present. In fact, it is generally realized that when a field is abandoned more oil remains in the sand than has ever been removed. As a consequence of this realization, the petroleum engineer has devoted considerable tine in recent years in devising methods for increasing the percentage of recovery. His studies have indicated that in most cases the total production of a field is dependent upon the available gas rather than upon the available oil. Mien the gas in the sand is exhausted, oil production ceases even though there may be enormous quantities of oil remaining unrecovered. Consequently, any method of conserving the gas or increasing the supply of gas will increase the ultimate recovery from a field. The practice of producing oil under vacuum increases the effectiveness of the gas remaining in the sand, as well as furnishing more gas by evaporating the light fractions of the crude. Pumping ' compressed gas or air down selected wells of a lease has been found to increase the production of oil from the surrounding wells. Studies of oil and gas ratios have indicated that much of the available gas has been wasted as far as its effectiveness on oil production is concerned. his has led to the development of "stop cocking"3 and the practice of producing under back pressure3, which methods aim, to obtain more effective work from the gas with reference to the amount of oil delivered to the well.

Jan 1, 1926

By Wesley A. Grosh

The Sutherland copper prospect is situated in Floyd County, Va. The immediate area was prospected around 1850, and one of the adits possibly dates from that time. Little or no ore has been mined from the deposit. The deposit is a mineralized sulfide zone occurring in mica schist and consisting mostly of pyrrhotite with minor amount of copper. A magnetometer survey of the deposit by the American Metal Co. in 1939 showed an anomaly that was thought to indicate a zone: of secondary enrichment. The Bureau of Mines diamond-drilled 14 holes, totaling 913 feet, and opened an adit during February and March 1943. No appreciable copper values or indications of secondary enrichment were found.

Jan 1, 1948

By S. D. Maksimovic

The Bureau of Mines identified and evaluated major sources of quartz dust during overburden drilling at a surface coal mine, The relative contribution of each source to the total dust hazard was estimated, using personal gravimetric and instantaneous dust-sampling devices. No attempt was made to determine actual dust generation rates. The major sources of dust at the drill rig during dry drilling opera-tions were the collector dump, drill shroud leakage, and drill stem seal leakage, These sources contributed 90 pct of the respirable dust and 89 pet of the respirable quartz dust generated during drilling, The collector dump cycle (21.6 pct of total drilling time) accounted for 38 pct of the respirable dust and 41 pct of the respirable quartz dust, with peak dust concentrations reaching 68 mg/m3. Shroud and drill stem leakage contributed 28 and 24 pct of the respirable dust and 32 and 16 pct of the respirable quartz dust, respectively. A dragline and second drill rig contributed the remaining 10 pct of dust and 11 pct of quartz dust. Gravimetric dust samples collected inside the drill cab and outside, near the cab door, averaged 1.65 and 1.43 mg/m3, respectively, with 6 pct respirable quartz.

Jan 1, 1985

By J. G. Croeni

The titanium-iridium alloy system was investigated to determine whether alloys of this system would merit further development as control-rod material for nuclear reactors. A study was made to determine the titanium-iridium phase diagram by using melting-point, thermal analyses, X-ray diffraction, dilatometric, electrical resistivity, and metallographic techniques. The titanium-iridium alloy system was investigated between 500° and 2,400° C. Results indicate the formation of two intermetallic compounds, Ti3Ir rind TiIr3, and one intermediate solid solution centered about the 50 atomic percent iridium composition. A eutectic reaction occurs at 1,475° C, and 19 atomic percent iridium. The Ti3Ir decomposes peritectically at 1,520° C. The intermediate solid solution exhibits a maxima of 2,140° C. at 50 atomic percent iridium. This phase is also believed to undergo an order-disorder transformation at 1,750° C. Another eutectic reaction takes place at 2,000" C. and 60 atomic percent iridium. The compound TiIr3 formed at 75 atomic percent iridium decomposes peritectically at 2,115° C. Further increases in iridium content result in the formation of an iridium-rich terminal solid solution. Information obtained below 900° C. in titanium-rich alloys indicates that iridium acts as a beta stabilizer in titanium, and the authors believe that a eutectoid decomposition of beta-titanium occurs near 500° C. and 10 atomic percent iridium.

Jan 1, 1962

By John P. Coughlin

Software techniques developed by the Bureau of Mines Denver Research Center for real-time microseismic data analysis are presented. These techniques focus on the simple acquisition of P-wave arrival times and their use in event location. The paper discusses in detail software techniques to separate microseismic events from mining noise such as drilling and from very large events such as rock bursts. Incorporation of these techniques has enhanced the reliability and accuracy of computer-based monitoring of microseismic activity in ongoing research by the Bureau.

Jan 1, 1982

By W. F. Marshall

The effect of engine parameters on exhaust emissions from two diesel engines was studied experimentally. Fuel-injection characteristics and intake air conditions were considered as parameters influencing the emissions. Emphasis was placed on the effect of parameter variations on nitrogen oxide (NOx) emissions, because diesels generally emit very low levels of carbon monoxide (CO) and unburned hydrocarbons. Emissions other than NOx were at lowest levels when the engines were adjusted for best performance. NOx emissions can be diminished somewhat through variation in fuel-injection characteristics, but there generally are penalties in emissions of CO, smoke, and unburned hydrocarbons or in engine performance. Temperature and composition of intake air have a significant effect on NOx emissions. Levels of NOx are reduced by recirculating the exhaust gas or by adding water to the intake air stream. However, the rate of water added or exhaust gas recirculated must be limited to prevent the degradation of engine performance and increased emissions of CO and smoke. At high exhaust recirculation rates, levels of CO and smoke were increased such that it was necessary to derate the engine and also to use a catalytic system for oxidation of CO.

Jan 1, 1971

By Robert C. Gabler

The extraction of metals from coal ash was investigated by the Bureau of Mines in an effort to produce a more environmentally acceptable waste and offset waste disposal costs with recovered metal values. The research was conducted in two steps: determination of the parameters that affect extraction of metals from coal ash and development of extraction-recovery procedures. Data obtained indicate that the major parameter affecting the extraction of metals from coal ash is the calcium content of the ash. Other parameters such as furnace type and operating temperature had much smaller effects on metal extraction. Two procedures were studied for metal extraction: an acid leach procedure for high-calcium ashes and a lime sinter-acid leach procedure for low-calcium ashes. An alumina product was recovered that, with sufficient washing, meets Hall cell specifications. The leach residues pass the EPA EP Toxicity Test and are thus nonhazardous wastes available for a variety of uses.

Jan 1, 1983

By John Ward Smith

Oil-yield data are presented for core samples from Colorado Corehole No.1, drilled by the Bureau of Mines and the Atomic Energy Commission in a previously untested oil-shale area near the northern edge of Colorado's Piceance Creek Basin. Continuous oil shale 2068 feet thick, averaging 18.41 gallons of oil per ton of shale and representing 1.8 billion barrels of oil per square mile, occurs at the core site.

Jan 1, 1968

By John J. Mulligan

Ear Mountain is an isolated mountain mass that rises abruptly from the coastal plain on the northwest shore of the Seward Peninsula. Geologically it resembles the more accessible Brooks Mountain and Cape Mountain areas to the southwest, being composed of a granitic core surrounded and partly capped by metamorphosed sediments. The occurrence of lode- and placer-tin deposits in this area has been known since the early 1900's, when the Seward Peninsula region was prospected extensively for both gold and tin. The Federal Bureau of Mines investigated the tin deposits in the Ear Mountain area during the 1953 and 1954 field seasons. The objectives were to delimit the areas in which tin minerals occur, as a guide to future prospecting, and to determine the amount of tin in the known prospects. Work by the Bureau of Mines included both placer and lode sampling.

Jan 1, 1959

By E. C. Lane

This report on properties of commercial motor fuels is the twelfth in a series made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the United States Department of the Interior. The first report contained data on motor gasolines sold during the winter of 1935-36.V The -present report, covering the summer of 1941, presents analytical data for 1,857 samples, representing the products of approximately 135 companies. As in previous surveys, these companies include both large and small suppliers. In addition, the Pacific coast is represented by data averaged by the Pacific Coast Technical Group before being submitted, and these data are published exactly as they were received. Conforming to previous surveys, the data cover three groups of samples -- regular-price, premium-price, and third-grade gasolines -- and each group has been aver aged separately. The number of samples, items, and brands comprising each group, exclusive of those of the Pacific coast, are as follows: Regular price, 1,010 samples, 291 items, and 86 brands; premium price, 577 samples, 263 items, and 78 brands; third-grade gasoline, 270 samples 159 items, and 74 brands. The meanings of these terms as used in the surveys are as follows: Sample: The individual supply of gasoline obtained at the filling station and analyzed in the laboratory.

Jan 1, 1942