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By J. P. Capp

This experiment, one of a series on underground gasification of coal, was an investigation by the Federal Bureau of Mines of hydraulic fracturing as a means of increasing the air acceptance of a coalbed to permit introducing combustion air and removing product gases. Specific objectives of the investigation included: (1) Fracturing a coalbed; (2) determining the distance the coal was physically affected; (3) ascertaining the effect of the fracture on air acceptance of the coalbed; and (4) gasifying the coal. The coal was fractured with a fluid consisting of 15,000 lb. of sand mixed with 10,000 gal. of fuel oil and 5,000 gal. of kerosine, injected at pressures up to 900 p.s.i.g. and rates up to 425 g.p.m. The oil served as the fracturing medium, and the sand as a propping agent to hold the fracture open. From the fracture point, (the place in the bed where the fluid was injected), the fracture extended 200 ft. or more along the face cleats, somewhat less along the butt. cleats, and was confined to the coalbed. At the fracture point, the bed accepted about 500 std. c.f.m. of air, which was an etghtyfold increase. Fracture effects were extensive, as airflow was noted from old mine workings and outcrops 600 to 800 ft. from the fracture point. It is probable the actual fracture was much less than 600 ft. and that normal coalbed permeability beyond the fracture limits was responsible for this flow. This indicated that effects of the fracture extended beyond the area of coal physically affected. Although no attempt was made to gasify coal more than 200 ft. away, these effects plus the natural permeability of the bed likely would permit combustion beyond the outer limit of the fracture. As these experiments continued for more than 2 years, and greater air acceptance due to the fracture was observed at the beginning of each test, it is apparent that the effects of the fracturing persist for a considerable time.

Jan 1, 1960

By Bruce Pinkston

This report presents a description of the Prototype Demonstration Vehicle and Safety Guidelines developed under U.S. Bureau of Mines Contract No. JO 366003, ?Improving Man Transit Safety. This vehicle was constructed to assess the feasibility of a set of equipment related guidelines which were drafted in Phase I of the same contract. State-of-the-Art improvements are embodied in such areas as collision survivability, occupant comfort, and multiple mode (on and off rail) operation. The electric battery powered vehicle carries a twelve man section crew at speeds up to 12 mph. The description of the demonstration vehicle Is presented In Volume I. Safety Guidelines are presented in Volume II.

Jan 1, 1981

By C. W. Huggins

The primary objective of this Bureau of Mines research was to measure the size distribution of respirable quartz collected at metal mines, nonmetal mines, and processing plants to select the best reference standard for use in quantifying quartz in mine and plant dust samples. The secondary objective was to size all the nonquartz particles collected at the same sites. Particle size measurements were made on 29 samples using a scanning electron microscope in the backscatter mode of operation, interfaced with an image analysis system. The Mine Safety and Health Administration, Denver, CO, provided the 29 samples, which were collected at mines and processing plants in 19 states. The accumulated particle size measurements indicate that NBS 1878, minus 5-f.lm Hin-U-Sil, and minus 5-f.lm Supersil would be preferred over Silver Bond B as reference standards for most quantitative determinations by X-ray diffraction and infrared spectrometry. The respirable dust samples collected at sand plants, however, would be better served by a new reference standard having a quartz particle size distribution of approximately 2.2 um, as none of the four existing reference standards matched closely with them. Commercially available NBS 1878 and minus 5-um Hin-U-Sil CQuid be used as reference standards for 28 of the 29 samples studied in this investigation.

Jan 1, 1986

By Roy E. Peterson

The Bureau of Mines has been developing and evaluating methods for beneficiating the large deposits of nonmagnetic (oxidized) taconite located on the western Mesabi Range. In this segment of the research, a sample representing about 0.5 billion tons of nonmagnetic taconite from near Grand Rapids, Minn., was beneficiated using a reduction roasting, magnetic separation, flotation process. The sample contained 32.1 pct iron and 49.1 pct silica. Tests were conducted both on a bench scale and with a 1,000-lb/h pilot plant. In the bench-scale research a con-centrate containing 69.0 pct iron and 4.5 pct silica was produced with an iron recovery of 82.1 pct. In the pilot plant, reduction roasting was conducted in a 35-ft kiln using lignite as the reductant and major source of fuel. Dust from the kiln exhaust was pelletized and recycled to the kiln. The roasted taconite was beneficiated by magnetic sep-aration and flotation to produce a product containing 67.9 pct iron, 5.5 pct silica, and 69.7 pct of the iron in the kiln feed. The cyclone separation in the grinding circuit was sharpened by demagnetizing the cyclone feed in a 400-Hz, 1,000-Oe magnetic field.

Jan 1, 1983

By C. G. Storm

Permissible explosives are those that have passed the tests pre- scribed by the Bureau of Mines for explosives intended for use in coal mines, and are therefore recommended by the bureau as suitable for this class of work when used under the prescribed conditions. The tests for permissible explosives and the conditions prescribed for their use are described in Miners' Circular 6 of the Bureau of Mines. Up to June 1, 1915, 168 explosives had been classed as per- missible explosives; 133 of them were then on the bureau's "per- missible list" and 35 had been withdrawn by the manufacturers. In addition to the required physical tests, each explosive is sub- jected to a complete chemical examination in order that its exact composition may be known and also that the composition of future samples of the same explosive collected in the field may be compared with that of the sample which originally passed the bureau's tests, for by such comparison it may be possible to ascertain whether or not the explosive as supplied to the miner is still "permissible." This bulletin is published primarily for the purpose of informing manufacturers of such explosives as to the methods used by the Bureau of Mines in the analysis of samples received for tests to determine their permissibility. Such information may be of value in cases of possible controversy over the results obtained in the analysis of a field sample as compared with those obtained in ana- lyzing the sample originally tested by the bureau. Also, a descrip- tion of the methods used by the Bureau of Mines in the analysis of explosives should be of assistance to the many chemists engaged in similar analytical work.

Jan 1, 1916

By Dean H. Ambrose

Using three-dimensional (3-0) graphics computing to evaluate new technologies for computer-assisted mining systems illustrates how these visual techniques can redefine the way researchers look at raw scientific data. The U.S. Bureau of Mines is using 3-D graphics computing to obtain cheaply, easily, and quickly information about the operation and design of current and proposed mechanical coal and metal-nonmetal mining systems. Bureau engineers developed a graphics simulator for a continuous miner that enables a realistic test for experimental software that controls the functions of a machine. Some of the specific simulated functions of the continuous miner are machine motion, appendage motion, machine position, and machine sensors. The simulator uses data files generated in the laboratory or mine using a computer-assisted mining machine. The data file contains information from a laser-based guidance system and a data acquisition system that records all control commands given to a computer-assisted mining machine. This report documents the first phase in developing the simulator and discusses simulator requirements, features of the initial simulator, and several examples of its application. During this endeavor, Bureau engineers discovered and appreciated the simulator's potential to assist their investigations of machine controls and navigation systems.

Jan 1, 1992

By A. J. Kraemer

The properties of crude petroleum continue to interest the Bureau of Mines and constitute an important phase of its major studies on the mineral resources of the United States. The Bureau's interest in the subject has been intensified by frequent requests for information on the characteristics of crude petroleum from various producing fields. Since its inception the Bureau of Mines has collected and analyzed samples of typical oils and at present has surveyed and classified crude petroleums from nearly all the known oil fields of the Western Hemisphere. Results of these surveys have been presented in various Bureau of Mines publications. (See bibliography, appendix A, p. 145.) The nature and comparative value of crude oils from various countries and the extent to which these oils may be considered potential competitors for markets are of manifest importance to the petroleum industry in all lands, largely because all crude oils, wherever produced, are either actual or potential competitors for a market with all other crude oils. The numerous discussions of foreign production of oil that have appeared in the technical press in the past indicate the great interest of the United States in this subject.

Jan 1, 1937

By Rogers F. Davis

This publication has been prepared to supply manufacturers and industrial users a listing of mobile diesel-powered equipment and subassemblies approved and certified by the Bureau of Mines for use in nongassy noncoal mines and tunnels. This revised and supplemented listing supersedes an earlier publication2 released in 1963. Testing of diesel-powered equipment is one phase of the Bureau's program of health and safety that concerns approval of electrical and diesel equipment designed to prevent explosions, fires, shocks, or toxic hazards in underground mines, when such equipment is used and maintained properly. Manufacturers submit machinery and component parts to the Bureau for study of their design, safety features, and use. Equipment must pass exacting tests and must meet strict requirements established through research and experience and outlined in the Bureau's permissible schedules before the Bureau approves it for safe use in mines.

Jan 1, 1968

By S. H. Ash

THE MAGNITUDE of the drainage problem of the anthracite industry in Pennsylvania's Western Middle field is realized when it is known that in 1951 nine pumping plants in this field pumped nearly 36 billion gallons of water to the surface. This is almost 68,000 gallons per minute pumped against an average hydrostatic head of 350 feet for that year alone. In 1948 over 20,000 gallons per minute was pumped by relay pumps against an average hydrostatic head of 265 feet. In addition to the water pumped to the surface, it is estimated that 15,000 gallons per minute overflows to the surface from underground pools in idle mines. The volume (second-feet) of water pumped and overflow water is almost 1;z times the, average mean flow of the Schuylkill River at Pottsville for the 8-year period 1944--51 (7, 13).4 Mahanov and Shamokin Creeks drain an area of 99 square miles in the Western Middle field, and all surface drainage in this area must traverse some part, of the coal measures before entering these streams. On the basis of 46.03 inches of rainfall (the weighted average of 6 recording stations for 1948), the runoff from the drainage area during that period was 51 billion gallons, approximately 1 times the volume of water pumped by all mine-pumping plants in the Western Middle field. In other words, because of the pervious strata overlying the mine workings, approximately two-thirds of the total runoff in the drainage, area becomes mine water tributary to the pumping plants.

Jan 1, 1953

By John A. Johnson

Conclusions regarding the use or omission of stemming in blasting have not peen reached, pending completion of all aspects of this investigation. The results from the dust phase of this study on six classes of stemming prove that the kind of stemming affects the amount of dust produced from blasting. In previous work at the Mount Weather testing adit it was demonstrated that blasting produces the highest dust concentrations of any of the mining processes.5/ Under the conditions prevailing at the Mount Weather testing adit, the average of all rounds having a break of at least 95 percent showed that the least amount of dust was produced when no stemming was used.

Jan 1, 1940

By John A. Johnson

Conclusions regarding the use or omission of stemming in blasting have not peen reached, pending completion of all aspects of this investigation. The results from the dust phase of this study on six classes of stemming prove that the kind of stemming affects the amount of dust produced from blasting. In previous work at the Mount Weather testing adit it was demonstrated that blasting produces the highest dust concentrations of any of the mining processes.5/ Under the conditions prevailing at the Mount Weather testing adit, the average of all rounds having a break of at least 95 percent showed that the least amount of dust was produced when no stemming was used.

Jan 1, 1940

By L. Kaufman

A range of processing conditions and compositions have been evaluated in order to optimize the properties of TiB2-(Ni,Cu) composites for application as a non-sparking tool material for use in coal mining operations. Fifty billets containing from 70 to 9S weight percent titanium diboride were hot pressed at 3000 psi between 2400°F and 2650°F. Samples which were cut from these billets were used to measure hardness, bend strength and impact strength so that composition/processing optimization could be effected. Eight compositions selected on this basis were evaluated by incendivity tests in order to choose the best composition. The best results were obtained for an 85 w/o TiB2-12 w/o Cu-3 w/o Ni composite hot pressed at 2650°F and 3000 psi. This material appears to be the best choice for fabrication of coal cutter bits to be evaluated in field tests.

Jan 1, 1973

By B. W. Gandrud

[The Bureau of Mines is conducting an extensive investigation of coal preparation in the Alabama coal fields in cooperation with the University of Alabama coal-mine operators. In this investigation the drainage characteristics of typical coals from the Warrior and Cahaba fields were studied]

Jan 1, 1941

By J. B. F. Champlin

The continuing development of the nuclear industry in the United States requires a program of waste disposal that insures against the release of large amounts of radioactivity to the environment. This paper describes research on one proposed means of disposal of this waste, that of injection into geologic formations at depth. Nuclear production plant wastes were simulated and injected into samples of sedimentary rock obtained from outcrops, quarries, and deep wells. Changes in the chemical and physical characteristics of the rocks caused by the interaction of ions and suspended particles in the waste solutions with the cementing material and claylike particles in the rock are discussed. Laboratory tests show that nuclear wastes can be injected into many natural porous, permeable geologic formations. Injectivity can be maintained over a longer period by monitoring the ionic balance and particle-size distribution of waste streams. The combination of permeability and porosity with low cation-retention capacity, as exhibited by most sandstones, would satisfy the engineering requirements for the subsurface disposal of nuclear waste. Shales and clays with their low permeability and high cation-retention capacity would make excellent confining formations. The amount of cation retained by sedimentary rocks increases with increasing valence or concentration of the cation or decreasing brine concentration. The use of rock cores as model reservoirs had proved successful in determining some of the parameters that need to be considered in full-scale field disposal of wastes.

Jan 1, 1967

By Roy T. Sorensen

The Bureau of Mines has investigated the recovery of cell-grade alu-mina by RCI leaching of calcined kaolin in the alumina miniplant at its Boulder City (NV) Engineering Laboratory. Classification and thickening were used for separating aluminum chloride leach liquor from the siliceous residue generated in the acid leaching step of the clay-HCI process. Coarse solids were classified from fines at 115 mesh and countercurrently washed in three additional spiral classifiers. Fines were treated in a conventional five-thickener, countercurrent decantation circuit. When this method was applied to the solids-liquid separation of slurry from RCI leaching of minus lO-mesh calcined kaolin, 75 pct of the residue reported as classifier sands and 25 pct as thickener underflow. Predicted individual classifier and thickener area requirements were 6 and 25 ft2/tpd, respectively. Total thickener circuit flocculant requirement was 2.4 lb/ton solids. Aluminum chloride pregnant liquor was produced that analyzed 8.4 pct A1203 and contained more than 97 pct of the alumina in the liquid phase of the slurry. Bench-scale settling tests were used to correlate fines content of leach residue to thickener area and flocculant requirements.

Jan 1, 1983

By W. J. Huff, G. W. Jones, I. Spolan, R. E. Kennedy

"INTRODUCTION Information on the exploeibility and ease of ignition of acetylene is important in connection with investigations by the Bureau of Mines and others seeking the causes of explosions in medium-pressure acetylene generators.A previous report 6/ gave preliminary results of an investigation made by this Bureau to determine the causes of these explosions. This report indicated the need of amending Federal specifications for ""1/4 by 1/12"" carbide to reduce the amount of fine sizes permitted under the specifications then in force. Tests described in the above report showed that certain sizes of carbide may, under certain conditions, attain excessively high temperatures when acetylene-water vapor mixtures are passed through carbides for extended periods.Federal specifications P-0-101, Amendment 5, June 28, 1944, are now in effect. These latest specifications permit a maximum of 7 percent of ""1/4 by 1/12"" carbide by weight to pass through a 0.0661-inch sieve and a maximum of 2 percent to pass through a 0.0555-inch sieve. Experience has shown that these specifications have insured a safer size range of carbide for medium-pressure acetylene generators.Although the improvement in the size range of the carbides has aided in the prevention of explosions, there have been explosions in which the carbide used at the time of the explosion met the latest Federal specifications."

Sep 1, 1945

By William Y. Mo

This Information Circular provides a detailed background documentation of how the Bureau of Mines projects U.S. mineral demand to the year 2000. These statistical projections serve as a quantitative basis for contingency forecasting of the low, high, and probable U.S. demand for nonfuel minerals by end-use categories and are published in the Bureau of Mines Mineral Commodity Profiles and Mineral Farts and Problems series. Aluminum is used as an example in this study.

Jan 1, 1980

By Bernard Porter

The densities of LiF, NaF, and KF, of binary mixtures of these alkali fluorides, and of binary mixtures of UF4, ThF4, YF3, LaF3, and CeF with each of tie alkali fluorides were measured as functions of the melt composition and temperature. Molar volumes at 1,000° C were calculated for all the mixtures. Binary systems containing LiF exhibited molar volume ideality. Binary fluoride systems containing either NaF or KF as the alkali fluoride exhibit positive deviations from molar volume additivity. However, molar volumes in the NaF-KF system are ideal.

Jan 1, 1966

By PAUL L. FISHER

This bibliography has been compiled by the Bureau in answer to many requests now being received for information on the briquetting coal and other carbons . In addition to publications issued by the Government in printed or mimeographed form, references are included to articles appearing in the technical press and in cooperative reports of work done jointly with states , colleges , and industries . References and patents are arranged in chronological order . Bureau of Mines bulletins , technical papers and Minerals Yearbooks are printed , and are obtainable from the Superintendent of Documents ,. Government Printing Office , Washington 25 , D. C. Reports of investigations , information circulars , and the directories and reports of the mineral industry surveys are published in mimeographed form and may be obtained without charge from the Publications Distribution Section , Bureau of Mines , 4800 Forbes Street , Pittsburgh 13 , Pa . Many Bureau of Mines publications , as well as bound copies of the foreign and American scientific and trade periodicals , may be consulted in technical , college , and large public libraries throughout the country. Dealers in new and second-hand books sometimes have copies of these reports for sale .

Jul 1, 1948

By E. R. Bauer

This report presents the results of a cooperative study between BethEnergy Mines Inc., Ebensburg, PA, a central Pennsylvania coal mining company, and the U.S. Bureau of Mines to investigate longwall development entry roof instability. In-mine mapping of geologic and deformational features was conducted to reveal the major ground control problems encountered during gate road development. In addition, mining-induced pillar load monitoring was used to indicate development loading on variously dimensioned gate road pillars and to determine if pillar yielding occurred. Finally, visual observations of a variety of roof control methods were used to determine the most effective support elements for controlling cutter roof failure.

Jan 1, 1992