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By N. A. C. Smith

During the past, six, years, the Bureau of Mines has made and. published several hundred analyses of typical crude oils and 'has developed a system of interpreting the analyses and of classifying crudes. This system is presented here with. It is apparently equate for classifying crude oils into four main groups and has also been found very convenient in studying the geological relationships between crude oils, and the probable refinery yields of valuable products from them. Crude petroleum is morn to be a very complex substance. An analytical statement of its properties must, therefore, consist of two distinct parts, - first, the report of the results of the determinations made by the analyst in the laboratory, - second, the proper arrangement, classification and interpretation of these results so that the analysis, as a mole, will indicate the meaning- and the relative- importance of the essential characteristics of the oil.

Jan 1, 1927

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Jan 1, 2012

By G. W. Eiger

Bureau of Mines laboratory tests show that ilmenite concentrates with titanium dioxide contents as low as 33 wt--pct can be beneficiated to produce a crystalline substitute for natural rutile suitable for direct chlorination. The synthesized product prepared by a three-step procedure was comparable with natural rutile in titanium content. Reduction smelting of ilmenite removes iron as a pig iron byproduct, and the remaining slag phase is greatly enriched in titanium. Oxidation of the slag in the presence of phosphorus¬bearing slag additive converts the titanium-bearing phases to discrete rutile crystals and a glass phase containing most of the associated impurities. Rutile is separated from the glassy impurities by attrition scrubbing ground slag in dilute phosphoric or sulfuric acid solutions. Tests made in a laboratory fluid-bed reactor show that synthetic rutile responds to chlorination at the same rate as natural rutile and that more than 95 pct of the titanium contained in the feedstock was extracted as titanium tetrachloride.

Jan 1, 1974

By M. Kanda, W. D. Bensema, J. W. Adams

Two different techniques were used to make measurements of the absolute value of electromagnetic noise in an operating coal mine, Itmann No. 3 Mine, located near Mullens, West Virginia. The electromagnetic environment created by 250-volt-dc and 550- and 950-volt-ac machinery in two longwall panels was measured and is reported. One technique measures noise over the entire electromagnetic spectrum of interest for brief time periods. It is recorded using broadband analog magnetic tape, and the noise data is later transformed to give spectral plots. The other technique records noise amplitudes at several discrete frequencies for a sufficient amount of time to provide amplitude probability distributions. The specific, measured results are given in a number of spectral plots and amplitude probability distribution plots.

Jan 6, 1974

By E. D. Wilson

This is the second of a series of progress reports describing work undertaken at the San Manuel copper mine to study the geologic factors influencing block caving of the deposit. The first report described the work done from April 1954 to March 1956.3/ This report describes the progress from March 1956 through March 1958 and presents additional maps, factural data, inferences, and conclusions resulting from a continuation of the underground geological work. As outlined in these reports, the study thus far has shown that the principal geologic factors affecting block caving are structure, rock types, alteration, mineralization, oxidation, and presence of water. Structure is fundamentally the most important. Systematic fracturing governed the extent and grade of primary ore mineralization and tangibly affects the subsidence or ground movement, which extends from the mine workings to the surface because of the block caving.

Jan 1, 1960

By Kathleen J. D?Amico

THIS SUMMARY is identical to the summary given in volume III of this series of mineral production in the United States (including Alaska and Hawaii), its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico and of the principal minerals imported into and exported from the United States. For further details on production see commodity and area chapters. A summary table comparing world and United States mineral production also is included. Mineral production may be measured at any of several stages of extraction and processing. The stage of measurement used in the chapter is normally what is termed "mine output." It usually refers [ ]

Jan 1, 1958

By D. D. Dornenburg

The effect of changes of atmospheric pressure on methane emissions from extensive worked-out areas of coal mines in several Midwestern States has lone caused concern to State and Federal mining departments, as well as to the operating companies involved. Common mining and ventilation methods employed in mines in these States have resulted in large sealed and unsealed worked-out areas in which considerable quantities of methane are emitted alone both intake-and return-air courses. The common practice is to watch barometric changes very closely and take special precautionary measurer during periods of low barometric pressure. Although the hazard is recognized, mining officials have different opinions concerning the effect of barometric pressure variations on the emission of mine gases. These opinions are based upon scattered personal observations, as no records exist of actual studies to establish such effects.

Jan 1, 1955

By Terry S. Cory

This report is a comprehensive summary of the results of the propagation measurements program conducted for the US Bureau of Mines under Contract H0366028. Data was gathered in the MF frequency range from a cross sample of six mines representative of the industry having typical wireless requirements. From the raw data which was gathered, a logical method of data reduction is presented which culminates in a set of average attenuation characteristics for all mines visited. These characteristics define a typical MF wireless system when the communication range requirements are known. Direct through-the-earth propagation and the range enhancement mechanism due to coupling on and off conductors are evaluated and related to the planning of a typical wireless MF communications system.

Jan 8, 1977

By Joseph V. Mather, E. H. McCleary

"INTRODUCTION Workmen are transported in shafts in various types of cages or skips, most of which were designed primarily for hoisting cars and materials. Therefore, in general the cages or skips are not completely enclosed, adequate and gates are not always provided, and at many mines signaling devices and telephones are re¬stricted to those at the various landings in the shafts.Shaft accidents are usually severe - frequently fatal - and as a rule such an accident is caused by failure to comply with company rules or by ignoring them.Sixty men were killed and 555 men were injured in shafts of the anthracite and bituminous coal mines of the United States during the 5-year period 1938-42. 4/ Many of these accidents could have been prevented by having properly enclosed cages and adequate locking devices on doors to prevent workmen from falling into the shafts.The officials of the Heidelberg Coal Co. contemplated utilizing an old coal-hoisting shaft as a man-hoisting shaft; however, it was their desire to avoid the use of the conventional cage and to try to provide a safer means of transporting men in the shaft. Investigations and studies made by the officials revealed that an elevator similar to those used in large buildings would be more economical in first cost, maintenance, and operating costs would be less, and it would be safer and more convenient for the workmen. Effective safety devices for such elevators have been developed to such a high degree that those properly installed seldom fail. The elevator or man cage finally chosen cannot be pulled above the top landing through mechanical or man failure; it stops automatically at each landing and cannot be moved while a door is open; when the cage leaves the landing the doors opening to the shaft are automatically locked by mechanical and electrically operated locks; electric lights, telephone communication, and push-bottom controls are available on the cage, and adequate safety switches and overspeed controls are provided."

Jun 1, 1947

By W. L. Cornell

The Missouri Pb ores are the only domestic Co resource being mined and processed for other metals; therefore, they present a viable short-term opportunity for Co production. Lead, zinc, and copper concentrates are produced from the ore. The Cu concentrate can contain up to 30 pct Co and the Pb concentrate up to 15 pct Co. Since Co is detrimental to the processing of the Zn concentrate; the remainder of the Co is rejected to the tailings. The tailings can contain as much as 50 pet Co originally present in the mined ore. Researchers at the U.S. Bureau of Mines have successfully tested on a continuous basis a process that recovers a bulk sulfide concentrate from mill tailings. The concentrate contains up to one-half of the Co and from 50 to 90 pct of the Pb, Zn, and Cu. Concentrate weight represents 10 pet or less of the total tailings.

Jan 1, 1989

By Fred N. Kissell

The new MSHA diesel rules have stone mine operators looking hard at pos¬sible upgrades to their ventilation systems. There are existing methods to reduce diesel engine emissions (MSHA, 2001)(Head, 2001b),but many operators will decide that a ventilation upgrade is necessary is well. NIOSH hay several stone mine ventilation projects underway, but in the meantime a good information resource is the work done by the U.S. Bureau of Mines in the 70's and 80's on ventilation for oil shale mines. The Bureau conducted this research because oil shale mines were projected to be gassy and would, therefore, require a lot of ventilation air. The focus of this oil shale work was on the use of jet tans for lace area ventilation, and on stoppings that would he low Lost and leak-tight. The work also considered changes in mine design to reduce the number and size of stoppings. The findings are still applica¬ble to stone mines.

Jan 1, 2002

By Charles D. Litton

Laboratory experiments were conducted to determine the responses of a prototype smoke detector and a commercially available photoelectric smoke detector to smoke particles generated from various combustion sources. The prototype smoke detector combines optical scattering measurements with ionization chamber measurements in order to reduce/eliminate nuisance alarms due to the presence of airborne dusts or diesel exhaust particles. The commercially available smoke detector is designed for use in harsh environments where airborne dust represents a major problem due to both nuisance alarms and detector contamination. In the experiments, the responses of the two detectors were measured when exposed to smoke particles from the exhaust of a diesel engine and from a variety of fire sources, including wood, coal, styrene butadiene rubber, and No. 2 diesel fuel. For the solid fuels, data were obtained for both smoldering and flaming combustions. This report describes the experiments, their results, and the use of these results as they apply to early-warning fire sensors capable of the rapid and reliable detection of fires in atmospheres that may or may not be contaminated by either airborne dust or the products produced from diesel engines.

Jan 1, 2008

By BUREAU OF MINES

The cheapest method of handling gravel in placer mining operations is by hydraulic mining . In working gravel deposits by hydraulic mining , it is essential that an abundant supply of water under sufficient head can be economically developed and that there is sufficient grade for sluice boxes and for disposal of the tailing . Without dumping facilities , simple hydraulic mining is an impossibility . The cost of hydraulic mining may range from 2 cents a yard under favorable condıtions to 12 or even 20 cents under less favorable conditions and to 35 cents or more a yard in Alaska , according to conditions of operation , and if frozen gravel is encountered . When it is necessary to elevate gravel , the costs may exceed 60 cents a cubic yard . When the natural conditions do not permit of hydraulic pining proper , other methods of elevating the grade are employed , some of which are described below . Bucket dredging has replaced hydraulic mining in importance in California and other states where hydraulic mining was once extensively carried on , and is by far the cheapest method of elevating gravel when mechanical methods are required and the physical conditions are suitable for dredging . Dredging costs vary greatly under the different conditions encountered , and the total amount of gold to be recovered must of course be enough to warrant the cost of a dredge installation . Gold dredging operations in the United States are fully described in Bull . 127 , U.S. Bureau of Mines .

Jan 1, 1922

The Federal Mine Safety and Health Act of 1977* defines respirable dust as dust measured with a device approved by the Secretary of Labor and the Secretary of Health and Human Services [30 USC 842(e)]. The approved sampler for respirable coal mine dust is the coal mine dust personal sampler unit (CPSU) [30 CFR 74; Jacobson 1971; Jacobson and Lamonica 1969]. The CPSU is generally called the 10-mm nylon cyclone, although the 10-mm nylon cyclone is actually just one component of the CPSU. The CPSU may either be mounted on a worker (with the sampling head positioned in the breathing zone for personal exposure monitoring) or in a fixed location for area sampling [Tomb 1990]. The CPSU consists of a pump unit, a sampling head assembly, and a battery charger if rechargeable batteries are used in the pump unit [30 CFR 74.2]. The sampling head assembly contains two stages. The first stage is a 10-mm nylon cyclone, which has collection characteristics similar to an elutriator. The amount of dust penetration depends on the flow rate [Jacobson and Lamonica 1969]. The second stage is a membrane filter (vinyl, pore size 5 pm) that collects the dust passing through the cyclone. The dust collected on the membrane filter is weighed to a precision (standard deviation) of 81 pg [Parobeck et al. 1981], and the respirable dust concentration in the mine atmosphere is then determined from the mass of dust collected and the volume of air sampled [Tomb 1990].

Jan 1, 1997

By Stephen Utter

This report summarizes the procedure and results of an investigation to determine the stresses in the rock around an underground opening in the Climax molybdenum mine, Climax, Colo. This study is part of an overall investigation conducted by the Bureau of Mines to determine the stresses induced by block-caving mining. The purpose of this study is to obtain estimates of the magnitudes and directions of the principal stresses, the location of the maximum stress concentrations, and the effect of topography on the stresses.

Jan 1, 1962

By Guy A. Johnson

This Bureau of Mines report summarizes the results of efforts to develop reasonably priced, reliable mine shaft fire and smoke protection hardware for metal and nonmetal mines. The hardware was incorporated into a viable prototype system that would minimize fire and smoke hazards. The design of the system had to be sufficiently flexible to be utilized in a wide variety of metal and nonmetal mine shaft and shaft station configurations. As a result of long-term, rugged field tests, an improved (second generation) system was developed. The hardware is now commercially available.

Jan 1, 1978

By C. K. Rose

A hydraulic scaling rig was placed in operation at the Bureau of Mines oil-shale mine near Rifle, Colo., in 1953. The rig consists of a self-leveling platform mounted on a hydraulic-powered boom. The boom is mounted on the bed of a diesel truck. The equipment provides a movable work platform from which two men can work in safety and comfort while barring loose rock from the backs and walls of the rooms, pillars, and haulageways. INTRODUCTION As a part of its synthetic liquid fuels program the Bureau of Mines has developed a mine in the richer oil-shale beds of the Green River formation near Rifle, Colo. An important part of the work of the Oil-Shale Mining Branch is investigation of techniques for low-cost mining of oil shale on a commercial basis. It is evident that scaling loose rock from the high backs and walls of the mine represents a portion of the direct mining cost. This paper describes the development of a scaling rig for operation in the upper heading of the mine, which is 39 feet high.

Jan 1, 1954

By J. D. Hadden

The Bureau of Mines conducted drilling studies in the Pocahontas No. 3, the Pittsburgh, and a western coalbed to establish the gas migration characteristics for each. Gas pressures in the Pittsburgh coalbed were about 260 lb/in2 and in excess of 550 lb/in2 in the Pocahontas No. 3. Caving in drill holes prevented pressure measurements in the western coalbed. The Pittsburgh coalbed contained intersecting "clay veins" which formed gas pressure cells. Although these geological features hamper mining, they can be used to control the flow of methane into a mine working. Methane control techniques are proposed for the Pittsburgh and Pocahontas No. 3 coalbeds.

Jan 1, 1969

By B. H. Eccleston

Experimental work is reported showing the effects of gasoline characteristics on auto emissions. Fuel volatility is shown to influence evaporative losses, with the higher losses associated with higher volatility. Fuel front-end olefin is shown to contribute significantly to reactivity of emissions. Large vehicle-to-vehicle differences were found. The study was conducted by the Bureau of Mines at its Bartlesville Energy Research Center in cooperation with the Coordinating Research Council Air Pollution Research Advisory Committee. The work was done using 15 1968-70 model autos and eight fuels were tested at ambients ranging from 20° to 95° F. Data on emissions from each vehicle-fuel-temperature combination are presented. Also included are calculated photochemical reactivity data and the distribution of hydrocarbon and nitrogen oxides during the test cycle.

Jan 1, 1972

By Howard C. Turnage, Dana T. Updyke

An evaluation was made of one of several improved underground communication systems sponsored by the U.S. Bureau of Mines. The system evaluated was installed in a typical metal/non-metal room and pillar mine and utilized UHF repeaters connected to a unique distributed antenna and passive reflector system which provided mine-wide communications. A microprocessor controlled data collection system was assembled and installed for the evaluation. Data consisting principally of times and durations of messages and identities of the originating transceivers was collected between February and August of 1982 (6 mos.). Analysis of the data shows that the principal benefits are reduction in time required for unscheduled maintenance and repair, enhancement of safety, and better coordination of production activities. A cost benefit analysis shows a net benefit over cost, although it is also concluded that the capacity of the system is greater than can be justified by current activity in the mine.

Jan 2, 1983