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By C. G. Kirkland

An apparatus for determining trace impurities in Grade-A helium by mass spectrometer methods was designed and built by the Federal Bureau of Mines. Grade-A is the designation for helium commercially produced by the Bureau. Its nominal purity is 99.995 percent. The device, following a suggestion by Deaton, concentrates the impurities in the helium by freezing them out in a coil-and-trap assembly cooled by liquid helium. A known volume of helium is passed through the trap, the concentration ratio determined, and samples of the concentrated impurities are analyzed by mass spectrometer methods. The apparatus has been in service for approximately 20 months and has satisfactorily met all requirements. Over 200 analyses were made of helium contained in conventional cylinders, obtained from the Amarillo, Exell, Otis, and Navajo Helium Plants, during the 6-month period ending March I, 1959. Total impurity concentrations, in parts per million, were as follows: Amarillo, 19.1; Exell, 17.1; Otis, 11.3; and Navajo, 6.6. Neon and nitrogen were the major impurities. Complete data are shown in table 4 in the body of this report.

Jan 1, 1960

By Steven W. Schmauch

The Sugarloaf RARE II area (No. 5296) covers 11,100 acres in the northern part of the White Mountain Range, in the Inyo fictional Forrest. It is in Nevada, about 45 mi north of Bishop, California. A mineral survey was conducted by On U.S. burro of Mines in 1982 and by the U.S. Geological Survey in 1980-1982. The Bureau reviewed pertinent literature, searched Esmeralda and Mineral County mining records, obtained current claim information from the administrative agencies, and contacted claim owners. Thirty-six properties were examined, and 674 samples were taken from them to help assess win oral resources and potential. The Geological Survey evaluated the regional mineral potential by geologic, geochemical, and Geophysical surveys.

Jan 1, 1983

By D. Ng

A facility to evaluate the fire endurance of mine stoppings was constructed by the Bureau of Mines in the multiple entry section of the Bruceton (PA) Experimental Mine. Stoppings up to 6 by 18 ft can be tested in a manner simulating mine conditions. The stopping is subjected to a 70-min liquid fuel tray fire with an energy output of 75,000 Btu/min. The stopping and adjacent areas are instrumented with thermocouples and heat flux gauges. Data acquisition is by an automatic data logger capable of continuously recording over 100 channels of information. Two 8-in-thick concrete block stoppings and a galvanized steel stopping were tested. A crack developed on the fire side surface of the block stoppings where the flames were most intense. However, the temperatures of the unexposed surfaces of the stoppings never exceeded 800 C and the surfaces were undamaged. The steel stopping retained its structural integrity during the test. The temperature of the unexposed steel surface reached 5000 C, but combustible materials located 1 ft from the surface did not ignite. A 3/4-in-thick coating of construction plaster was applied to the fire side of the previously tested uncoated steel stopping. The quantity of heat energy transmitted across this coated metal stopping was reduced approximately 50%. All stoppings prevented the passage of flame and smoke.

Jan 1, 1988

By Frank S. Wartman

"The experimental flotation work described in this paper was undertaken to test the conclusions derived from a previous microscopic and chemical study of several samples of converter slag. That study3 resulted in the conclusion that approximately 90 per cent of the copper content of a converter slag wad in either the sulphide or metallic form, and that if the slag were cooled slowly the copper-bearing material would be in particles of such size that they would be freed from silicate and magnetite grains by grinding the slag to pass a 150-mesh sieve. If this were true, it should be possible to separate the copper-bearing grains from slowly cooled, converter slag by the flotation process.Many attempts, of which the author has seen no published account, have been made to treat slags, especially converter slags, by flotation. In every case these trials have been made with chilled slags, in which, as shown in the preceding report, the copper-bearing material is top finely disseminated, to be freed by any reasonable degree of grinding.The flotation tests described in this paper have shown that it is possible to recover by flotation about 30 per cent of the copper content of a converter slag containing 3 per cent copper and to obtain flotation concentrates which have a copper content of 35 per cent.Acknowledgment is made to G. L. Oldright, supervising engineer of the section of nonferrous metallurgy, U. S. Bureau of Mines, for valuable assistance and direction; to W. A. Sloan for chemical analyses; and to Alfred P. Towne for assistance in experimental manipulation."

Apr 1, 1931

To improve mining safety and efficiency by providing a practical way of detecting faults and channel sands that disturb coal seams. Approach A seismic system using a shallow blasthole has been developed and tested. How It Works A small shock is caused in a shallow hole, sending seismic waves through the ground. These waves are reflected from the top of the coal seam, acid are detected by a line of geophones on the earth's surface. Dampening of the seismic signals by channel sands and other discontinuities in the seam is detected and recorded. See Figure 1. The seismic shock wave can be produced by exploding small charges, dropping a weight, firing a gas gun, or actuating a vibrator. Depending on the soil cover, the shock is usually generated in shallow vertical holes about 10 feet deep. Hole depth depends on the soil mantle thickness because it is preferable that the seismic shock originate below that layer.

Jan 1, 1976

China?s New Steel Complex Postponed. - The planned $5 billion Baoshan Steel Works near Shanghai is being laid aside for 6 months to a year, and may be abandoned altogether. The second phase of construction, in which Wean United, Inc., of Pittsburgh was a major participant, has definitely been cancelled. Over $1 billion had been committed to the 6 million-ton-per-year plant. U.S. Firm Develops South African Fluorspar. - The Armco Bronne Co. of Middletown, Ohio, plans to spend $27 million to develop a fluorspar mine in the Republic of South Africa, With fluorspar reserves at 20 million metric tons, the project is planned to produce 200,000 tons Per year of fluorspar for export starting in 1983. U.S.S.R. Resumes Sales of Titanium Sponge. - Against a background of increased U.S. titanium sponge supplies, the Soviet Union is offering limited quantities of this commodity to the U.S. market at approximately $10.00 per pound, down from $25.00 per pound last year.

Jan 1, 1981

By R. V. Ramani, R. Bhaskar

"The spatial distribution of airborne dusts, deposition of dust in the airway, as well as the effect of airflow velocity and particle density on dust behavior in mine airways were studied in a set of experiments performed in a mine airway under controlled conditions. Considerable deposition of dust near the source was indicated. Pronounced effects due to velocity were observed in ambient dust concentration and deposition along the mine airway, both in the respirable and the total size ranges. Cross-sectional concentration measurements indicate an increase in concentration from the roof to the floor. The average cross-sectional concentration is about 75% of the concentration in the center of the airway.IntroductionA number of studies have been performed since the early 1950s on the behavior of dust in mine air (Bradshaw and Godbert, 1954; Dawes and Slack, 1954; Bradshaw et al., 1954; Hall, 1955-56; Reinhardt, 1971; Ford, 1971; Courtney et al., 1982). While the experimental data available from these studies are indeed useful in understanding dust cloud behavior in a specific situation, no generalized conclusions can be drawn because of the lack of data on parameters such as flow velocity, size distribution of the source dust, and particle density. These change from mine to mine or even within the same mine. The present study is aimed at providing a better understanding of the temporal and spatial behavior of dust particles in underground mine airways (National Academy ofSciences, 1980). The characteristics studied encompassed airborne concentrations and floor depositions over the entire size range as well as the respirable size range. The experimental results in this paper are intended to complement a mathematical model developed to predict ambient concentration and deposition of airborne dust in mine airways (Bhaskar and Ramani, 1986)."

Mar 1, 1989

By J. M. Pugliese

The Bureau of Mines, in support of its overall goal of helping to meet future U.S. demand for minerals, undertook this study to aid the quarry entrepreneur and/or operator in developing quarries near urban areas. In response to increased environmental concerns, the quarry operator often must take steps beyond those required in the last decade toward gaining permits for quarrying near metropolitan areas. Following the steps suggested in this report should increase the chances to obtain the permits to open and develop a quarry. Each task and question in the general plan flow diagrams are described in detail, with the flow diagrams aimed at the goal of acquiring the necessary permits. The appendixes include (1) types of projects for which Environmental Impact Statements (EIS's) may be prepared and Federal agencies responsible for preparing them, (2) State contacts for information regarding environmental impact assessment requirements and mining and mineral land reclamation laws, (3) a checklist of environmental inventory factors, (4) a tabulation of different regulations that affect mining in Michigan and the number of townships and counties that have each of the listed regulations, and (5) environmental logic associated with site selection. A central recommendation is that the quarry entrepreneur and/or operator coordinate plans at the beginning with local government officials (such as township supervisors and/or city and county planning board members), State and Federal officials, and public groups that will be affected.

Jan 1, 1979

By Alden H. Emery, J. J. Forbes

"IntroductionThe data contained in this paper were collected during the course of an investigation which covered 15 representative coal mines in 6 coal-mining States. The purpose of the investigation was to determine by atmospheric sampling how much dust was raised into the air during the various operations of coal mining, such as undercutting with machines, loading coal by hand, and transporting it from the working face to the surface. The data thus obtained were considered from two angles - namely, the possible physiological effect of inhalation and the explosion hazard of the dust. No attempt will be mode to discuss the former factor in this paper.CONDITIONS OF MININGThe mines in which this investigation was conducted were considered representative, and it is believed that the results obtained will suffice for the average dustiness encountered in most coal mines. .All of the coal mined was bituminous, from beds 30 to 120 inches thick. Only the ordinary room-and-pillar system of mining was employed. Daily production ranged from approximately 700 to 1500 tons and the men employed from 150 to 450. Coal was undercut by short-wall mining machines in all mines, with the exception of one in which pick mining was employed. Loading at the face was done by miners; none of the mines used mechanical loaders. Electric drills, both for brushing roof and for shooting coal, were commonly used although some roof work was done with jack-hammers and a. little of both with augers. Coal was hauled by motor, mule, or rope power in end-gate cars with capacities ranging from 1600 to 3600 pounds. With few exceptions, coal was won at the face by dry methods - that is to say, no water was employed fox wetting down the dust either during undercutting, loading, or transportation."

Feb 1, 1927

By Kenneth H. Johnston

This report describes an in situ combustion project and three waterflood projects in Allen, Anderson, and Wilson Counties, Kansas, that will be visited during the 1964 annual tour of the Kansas-Oklahoma Waterflood Association. Among the unique features of the projects are the movement of heavy crude oil through the reservoir and into the wellbore with energy furnished by burning s portion of the crude oil therein. Another feature is the simultaneous injection of C02 and water, through separate tubing into input wells during early development, to increase injectivity at moderate pressures, Discussion of individual projects includes information on their early history, source and treatment of injection fluids, oil production-decline curves, and the results of water injection on oil production.

Jan 1, 1964

By G. R. Hopkins

The average quantity of heat needed to refine a barrel of crude oil in 1934 was 638,000 B.t.u., or about as much heat energy as contained in 5 gallons of fuel.oil. Although the total heat utilized in 1934 was slightly above 1933, crude runs to stills increased 4 percent, hence the average requirement per barrel declined from 660,000 B.t.u. in 1933 to 638,000 B.t.u. in 1934 (see fig. 1). The average for 1934 constitutes a new record for firing efficiency, being just under the previous low of 1929. Heat consumption at refineries depends on many factors, of which the trends in yields of gasoline and lubricating oils are probably most important. The yield of gasoline is indicative of activity at cracking plants, which typo of plant utilizes more thou the average amount of heat per gallon of product. The yield of lubricating oils is indicative of the extent to which crude oil is refined; that is, it takes considerably more heat to refine a barrel of crude through lubricating oils than it does to separate only gasoline and kerosene. The yield of gasoline decreased from 43.7 percent in 1933 to 43.4 percent in 1934; on the other hand, the yield of gas oil and fuel oil increased. Although the yield of lubricating oils increased slightly in 1934 the theoretical increase in fuel requirements probably was offset by technical improvements, such as solvent refining. Although no outstanding technical developments of a fuel-saving nature were made in 1934, some progress undoubtedly was recorded. Heat exchangers, an effective fuel-saving device, wore enlarged, and some refiners now take off several cuts before the crude reaches the pipe stills. The total capacity of pipe stills increased 2.5 percent in 1934, and many of the less efficient shell stills were torn out.

Jan 1, 1935

By W. E. Miller, G. S. Scott, G. W. Jones

"INTRODUCTION One of the major activities of the Bureau of Mines is the promotion of safety in mining and the mineral industries. Research is undertaken in connection with these problems to determine the explosion and ignition hazards of combustible gases, liquids, and solids and to investigate means of reducing them.Occasionally the Bureau is asked to determine inflammability or ignition temperatures to enhance safety in nonrnineral industries. From time to time it has complied with such requests when no other agency was available to do the work and the investigation could be conducted with a minimum of time and expense. The present investigation is one of this class.Nicotine (C10H14N2), a colorless combustible liquid having a boiling point of 246°C, is usually obtained from tobacco and its products by extraction processes. When heated to its boiling point it decomposes; the purified product is obtained from tobacco extractions by distillation at reduced pressures or is distilled in a current of inert gas.It has an unpleasant odor, a burning taste, and in the undiluted state is highly toxic. Under certain conditions it can be oxidised to nicotinic acid and in the near future may therefore become of considerable economic importance. Nicotinic acid is a component of the vitamin B complex now commonly used to fortify white flour and other foods that normally are deficient in these vitamins."

May 1, 1942

Until man was able to produce light, his working day was pretty much limited to daylight hours. Underground miners have a special problem because in a mine it is just as dark during daytime as it is at night. The first devices used for mine lighting were torches and open flame 011 lamps. Torches made from twisted grass and dipped in tallow or pine pitch would burn for a while, but they made a lot of smoke and probably went out when they were needed most. During the 15001s, miners lamps consisted of a small metal dish with a hook attached to hang it up. The saucer-shaped dish was filled with animal or fish oil and a wick made of twisted fibers was laid In the 011 and hung over one edge where it would burn. This lamp would burn longer than a torch, but the amount of light cast by the pale, flickering flame was probably only a little better than no light at all.

Jan 1, 1976

By Özgen C. Karacan

It is generally accepted that typical coalbed gases (methane and carbon dioxide) are sorbed (both adsorbed and absorbed) in the coal matrix causing it to swell and resulting in local stress and strain variations in a coalbed confined under overburden pressure. The swelling, interactions of gases within the coal matrix and the resultant changes in the permeability, sorption, gas flow mechanics in the reservoir, and stress state of the coal can impact a number of reservoir-related factors. These include effective production of coalbed methane, degasification of future mining areas by drilling horizontal and vertical degasification wells, injection of CO2 as an enhanced coalbed methane recovery technique, and concurrent CO2 sequestration. Such information can also provide an understanding of the mechanisms behind gas outbursts in underground coal mines. The spatiotemporal volumetric strains in a consolidated Pittsburgh seam coal sample were evaluated while both confining pressure and carbon dioxide (C02) pore pressure were increased to keep a constant positive effective stress on the sample. The changes intemal to the sample were evaluated by maps of density and atomic number determined by dual-energy X-ray computed tomography (X-ray CT). Early-time images, as soon as CO2 was introduced, were also used to calculate the macro porosity in the coal sample. Scanning electron microscopy (SEM) and photographic images of the polished section of the coal sample at X-ray CT image location were used to identify the microlitho types and microstructures. The CO2 sorption-associated swelling and volumetric strains in consolidated coal under constant effective stress are heterogeneous processes depending on the litho types present. In the time scale of the experiment, vitrite showed the highest degree of swelling due to dissolution of CO2, while the clay (kaolinite) and inertite region was compressed in response. The volumetric strains associated with swelling and compression were between ± 15% depending on the location. Although the effective stress on the sample was constant, it varied within the sample as a result of the intemal stresses created by gas sorption-related structural changes. SEM images and porosity calculations revealed that the kaolinite and inertite bearing layer was highly porous, which enabled the fastest CO2 uptake and the highest degree of compression. Keywords: Coal; Carbon dioxide; Sorption; Swelling; Sequestration; X-ray computed tomography; Volumetric strain; Gas outbursts

By Jürgen F. Brune, R. Karl Zipf, Kenneth L. Cashdollar

This paper outlines the legal standards and methods for protecting underground coal mines in the United States from explosions of methane gas and coal dust. It will discuss inspection and monitoring of mine atmospheres, dilution of methane through ventilation, methane drainage prior to, during and post-mining, as well as explosion prevention through rock dusting and sealing of mined-out areas. Recent research findings of the National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory on the magnitude of pressures obtained during methane explosions from modeling and full-scale explosion tests at the NIOSH Lake Lynn Experimental Mine will be presented. This work is currently being applied to modeling the structural response of explosion-proof mine seals to pressures from gas explosions. Also, new research will be presented on the inertization of float coal dust in mines through the addition of inert stone dust and on the application of the Coal Dust Explosibility Meter (CDEM), a handheld device developed by NIOSH to directly measure the explosibility of a coal dust - limestone dust mixture based on optical reflectivity.

By Roy H. Grau, John C. LaScola

"This Bureau of Mines report contains a tabulation of methane emissions during 1980 for all coal mines located in the United States with emissions greater than 0.1 MMcfd. Listed for each mine are methane emission quantity, location, and coalbed. The report also compares records of 1975 and 1980 and describes relationships between emissions in 1980 and the Bureau's coalbed gas content data on 11 mines.INTRODUCTIONMethane gas is a threat to safety in underground coal mines. Research by Government and industry has led to great gains in reducing methane gas ignitions and explosions. The development of advanced methane control techniques is necessary for the safe operation of more gassy mines and the implementation of rapid mining techniques.As part of this research, the Bureau of Mines has surveyed total methane emission data from underground bituminous coal mines in the United States and tabulated emissions from mines producing over 0.1 MMcfd of methane. This report is an update of similar studies previously described in Information Circulars 8733, 8659, and 8558 (2-4).3The data from 1980 were compiled from Mine Safety and Health Administration (MSHA) records of air quality-quantity inspections made quarterly at each mine. The inspections involve measuring airflow and collecting air samples in the main returns. From these data, an average methane emission is calculated and used to represent the daily mine emission for each quarter. The methane emissions given in this report are the averages of the four 1980 quarters and do not include mine emissions from other sources such as degasification projects. Since a previous Bureau study showed that emissions from mines emitting less than 0.1 MMcfd represented only 2 pct of all emissions, 0.1 MMcfd was chosen as a lower limit for data collection (4)."

Jan 1, 1982

By H. H. Schrenk

[A calorimetric method3/ for the determination of benzene in amounts as low as 0.001 m has been developed recently at the U.S. Bureau of Mines Pittsburgh Experiment Station by the authors, with the assistance of chemical personnel from the Allegheny County (Pa.) Relief Works Division. The method is based on the direct nitration of either liquid or gas - phase benzene, followed by neutralization, extraction with butanone, and final treatment with sodium hydroxide which produces a violet color. The color is matched with color standards of known values. Although the method is adaptable to many conditions the primary objective was a procedure that would be suitable for hygienic investigations.]

Jan 1, 1935

These proceedings consist of an introduction and four descriptive papers. The first paper is an update on fire protection for large haulage vehicles, the second paper is concerned with improved visibility systems for large haul- age vehicles, the third paper is on improved ladders for large haulage vehicles, and the fourth paper is concerned with large haul-age vehicle operator training systems.

Jan 1, 1980

By Charles H. Etheridge

A new filter cassette is described which can be used with Coal Mine Dust Personal Sampler Units (CFR, Title 30, Part 74). The sealed cassette design reduces the chances of sample loss due to reverse flushing, impact or cassette opening. The filter capsule weight is approximately 400 milligrams and is stable for at least one year in storage. The alpha quartz content of the filter element is less than 5 nanograms per square millimeter of surface. The cassette is designed to be used with a new sampling head. The manufacturing costs of the new cassette will require an increase of approximately 30% in the selling price.

Jan 1, 1978

To develop an in-mine water treatment system in which bacterial sulfate reduction and limestone dissolution continuously remove metals and acidity from contaminated drainage. Approach A section of mine tunnel was converted into a water treatment bioreactor by constructing cinder block dams and fang the area between them with a porous substrate mixture of limestone gravel and compost. Readily fermentable materials such as dairy whey, spent brewing yeast, or sugar were periodically added to the reactor. Mine drainage was impounded behind one of the dams and continuously percolates through the reactor substrate at a controlled rate. How It Works The reactor substrate soon becomes anaerobic after it is saturated with mine water. Under anaerobic conditions, sulfate-reducing bacteria consume the organic materials that are added to the reactor and generate hydrogen sulfide (HIS) and alkalinity. The H2S reacts with dissolved iron and heavy metals to form metal sulfide precipitates. The alkalinity raises the pH of the water and induces aluminum to hydrolyze and precipitate as aluminum hydroxide [Al(OH)3]. Additional alkalinity is generated by the continuous dissolution of the substrate limestone. Metal sulfide precipitates and Al(OH)3 are retained within the reactor, and the treated water is discharged. The underground location of the system allows year round operation.

Jan 1, 1994