Search Documents

By ALBERT C. DURHAM

In anthracite mining , pumping is a problem of major importance , and water must be handled and rehandled in almost every mine whether the mine is in operation or idle . The motor - driven centrifugal pump is the most commonly used type of unit for the large pumping installations, and experience has . proved that fully automatic control has certain advantages over manual control . Some of these advantages are greater safety for maintenance personnel , continuous protection against faulty operation , which could cause damage to the Lumping apparatus , and lower pump -room operating costs .

Aug 1, 1948

By R. V. Ramani, V. T. Burgos, J. A. McClay

Cost System The cost system reported here is a suite of computer programs which incorporates the logic and information flow structure as outlined in earlier chapters. Specifically, computer programs have been devel¬oped to: 1. compute labor, operating, and capital costs, 2. summarize cost and production data, and 3. compute the minimum acceptable selling price for coal. While the cost system can be executed independently, it is de¬signed primarily for use with the Master Design Simulator and there¬fore must conform to the overall system hardware. The computer model is written in Fortran IV for use with the IBM System 360/370 computers as well as with compatible units such as the Univac 1110 and CDC-6600. For ease in error detection and program modification, the model was constructed with a main routine and eight subroutines. The main routine reads and stores the data necessary for the cost computations and calls the subroutines in logical sequence. The subroutines perform the cost computations and data adjustments for reporting purposes. Each subroutine performs the cost computations for its particular com¬ponent of the cost cycle. The program operations are described in the following narrative outline. Control Subsystem As previously described, the main routine is a passive element, reading and storing input data and directing execution to the active subroutines for cost calculations. Figure 10 is a macro-flow diagram

Jan 1, 1975

By W. E. Miller, Kennedy. R. E., G. W. Jones

"INTRODUCTION Ethyl mercaptan (CH3,CH2SH), a combustible organic liquid of the thioalcohol type, is employed at an odorant in many types of fuel gases and dangerous atmospheres, which in themselves are devoid of characteristic odors, to give warring against leakage of such gases or atmospheres into places where they might constitute health or explosion hazards.Ethyl mercaptan has a penetrating disagreeable odor resembling that of onions, garlic, hydrogen sulfide, or rotting cabbage, that exceedingly low concentrations of it can be detected. The of odorants as a beans of detecting leakage of gases and atmospheres has been investigated extensively by chemists and engineers of the Bureau of Mines, and numerous reports as to its value have been published."

Jun 1, 1942

By J. B. Newson

This is one of a series of circulars dealing with mining methods, practices, and costs. It describes the method of sinking a shaft 60 inches in diameter with a shot drill, as employed at the Idaho Maryland mine, Grass Valley, Calif. The operation involved a great deal of experimentation in applying the shot-drill method to large bore drilling, overcoming mechanical and other difficulties which developed during sinking, and developing operating technique. Under such circumstances, costs are obviously higher than they would be after the pioneer work has been done, but even so, these actually obtained compare favorably with costs of sinking by more conventional methods. ACKNOWLEDGMENTS The authors are indebted to Mr. Errol McBoyle, president of the Idaho Maryland Mining Co., not only for his cooperation and advice during the sinking of this experimental shaft, but for permission to prepare this article for publication with the inclusion of cost data.

Jan 1, 1936

By U. E. Brown

This papery describing the mining methods employed by the Bunker Hill and Sullivan Mining and Concentrating Co. at Kellogg, Idaho, is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the United States. The Bunker Hill and Sullivan mines are situated in the western part of the Coeur d'Alene district at Kellogg, Shoshone County, Idaho. The mines were discovered during the summer of 1885 and except for two short periods of labor trouble, between 1890 and 1900, have been in continuous operation. About 575 men are employed at the mine. The production is about 1,400 tons of lead-silver ore per day. This is treated in the company's concentrator and smelter at Kellogg.

Jan 1, 1931

By Homer J. Ballinger

A multiple drill carriage or "jumbo," which is believed to be unique in both design and performance, was constructed and has been in use for the past year at the Bureau of Mines experimental oil-shale mine near Rifle, Colo. This jumbo mounts four long feed percussion drills and is so designed that two men can operate all four drills. Before the jumbo was placed in operation, a minimum of eight man-shifts was required to drill 72 fifteen-foot holes in headings 60 feet wide and 27 feet high. The sane round is now drilled by two men in about 6 hours. Over 500 feet of drilling per man shift is easily and consistently accomplished. Use of the jumbo has resulted in a 75 percent reduction in drilling labor and a substantially lower drilling cost.

Jan 1, 1950

By Laurance L. Oden

The Bureau of Mines conducted corrosion tests of 18 commercial alloys in H3 P04 -phosphate rock or A1,03 slurry, in 10 pct HF, and in 25 pct H2 SiF6 to simulate three environments anticipated in a Bureau process to extract fluoride values from phosphate rock. Small alloy coupons were rotated in duplicate tests at 4.4 to 21 fps in the slurry at 170° C to determine rates of erosion-corrosion. At 4.4 fps the lowest rates, in mils penetration per year (mpy), were measured for Hastelloy C-276 (<20), Hastelloy B (30), and Inconel 625 (150);the rates increased at 21 fps to 55 mpy, 45 mpy, and 1,000 mpy, respectively. The corrosion rate for all alloys exceeded 40 mpy in either the equilibrium vapor or liquid phases of aqueous solutions containing 10 pct HF or 25 pct H2SiF6 at 100° C. Uniform corrosion in 10 pct HF at 50° C was observed only for Inconel 625 (22 mpy), Hastelloy C-276 (43 mpy), and Illium 98 (17 mpy). Inconel 625 (0.75 mpy), Hastelloy C-276 (1.3 mpy), Illium 98 (1.7 mpy), and Incoloy 825 (0.45 mpy) were attacked uniformly in 25 pct H2SiF6 at 50° C.

Jan 1, 1974

By Wesley A. Grosh

The Allah Cooper mine, in Louisa County, Va., formerly was a producer of lead and zinc. It was believed that the critical shortage of leach and zinc and the fact that some ore had been produced at this mine justified exploration of it. A preliminary examination was made on April 30, 1943, by J. E. Hill, a Bureau of Mines Engineer. Diamond drilling was done on the property from November 30 to December 18, 1943, to determine whether the sulfide body extended to depth. One hole drilled to a depth of 650 feet and located so as to cut the Allah Cooper ore shoot about 150 feet below the lowest known mine workings failed to disclose sulfide vein at that depth.

Jan 1, 1949

By Arthur L. Murray

"Oil-shale camps are peculiarly favored, in that before they are establishes it can be ascertained with a degree of certainty, that the life of the project is not limited. Unlike camps at metal mines, where the metal content of a given area is frequently an unknown quantity until after years of development, oil-shale camps should, from the outset, be planned and. built as permanent types of camps. Where this procedure is followed camps will be established which better serve the needs of the industry and the cost of their general care and upkeep will be less.Selection of camp or townsite.The site of the camp or town' whether on company property or not, should be selected with care. It should be separate if possible from the location of the plants of the company so as to be free from noise and fumes and so as to provide a change of environment for employees in going from their work to their homes.The principal features governing the site to be selected are as follows:Drainage. The general contour of the surrounding country should be such that drainage is away from the site. The camp or town should, if practical, be situated on higher ground than that in its immediate vicinity.Soil. The nature of the soil on which the camp or town is located may bear a decided relation to health. A porous, well underdrained top soil of at least four feet in depth insures dryness and facilities the placing of foundations and the laying of water mains and sewer pipes. Such a soil also is an advantage in growing trees, shrubs and grass plots, which are a decided adjunct to making the community attractive.Enviroment. The contiguous territory should afford no unwholesome sur¬roundings such as swamps Or accumulations of stagnant water.General Considerations. The water supply to be provided and the method of disposal of wastes influence to a certain extent the location of the camp or town-site. The means of supplying water, whether by gravity or by pupping, and the disposal of sewage, whether by outfall, system, sewage disposal system through septic tanks, broad irrigation or filter beds, or cesspools will govern the location of the site topographically in relation to source of water and point of disposal of sewage.* This article was prepared as part of the paper ""Use and Supply of Water for the Oil-Shale Industry"" by J. J. Jakowsky, to be published by the Department of Metallurgical Research, University of Utah, in cooperation with the United States Bureau of Mines."

Jul 1, 1921

By Roger J. Morrell

The Bureau of Mines conducted drag cutting experiments in hard, abrasive rock in an effort to extend the capabilities of an experimental kerf-core mining machine. The basic kerf-core mining machine cannot be used in hard, abrasive rocks because of the high wear experienced by the kerf cutters. These experiments were conducted in an effort to develop a method of preweakening the rock ahead of the kerf cutters in order to reduce the high cutting loads and hence the higher wear rates experienced by the cutters. The two "preweakening" techniques studied were indenting with mechanical wedges and single and double slotting with diamond saws. The best cutter force reduction achieved with mechanical indenting as 70 pct, whereas double slotting achieved force reductions of up to 99 pct. Conceptual designs of preweakening systems that could be retrofitted onto the basic kerfing cutterhead were developed for both the indenting and the slotting techniques. A high-energy impactor with wedge bit was used for the indenting method, and high-pressure water jets were used for the slotting method. A preliminary technical and economic analysis was performed for both of these full-scale systems to illustrate the methodology and to point out the important technical and economic factors that must be considered.

Jan 1, 1987

By D. T. Couillard

Video technology is becoming an important tool for many designers of industrial training programs. This report describes how trainers at the Minntac Mine, Mt. Iron, MN, have developed videocassettes of safe job procedures (SJP&apos;s) for training miners assigned to perform unfamiliar work tasks. All steps necessary for videocassette production, from idea to finished product, as well as the required equipment and prices, are listed and/or briefly explained. Minntac officials believe that the SJP videocassettes have contributed significantly to a reduction in mine accidents.

Jan 1, 1985

By A. W. Khair, S. J. Jung

"A fundamental study of fragment size distribution and characteristics of fracture pattern is presented for the dynamic penetration of a conical bit into coal block. In this paper, damaged zones during crater formation and fragment size distribution were studied. Bit with a sharper tip angle and a smooth body configuration performed better penetration. Results suggest that in coal cutting the trend should be toward the face cleat direction using a sharper angled tip bits which consumes less energy for an optimum range of penetration depths, thus attaining maximum cutting efficiency and reducing fine fragments.1. INTRODUCTIONMuch research in the past has been done on energy requirements and mechanism of energy dissipation for ideal rock fragmentation in cutting process. However the mechanisms of energy dissipation or failure criteria for rocks in cutting process in order to evaluate the efficiency of energy requirements in specific rock fragmentation is not well understood. The formation of a crater in rock under the impact blow of a bit has been observed experimentally (Hartman, 1959). It is known that directly beneath the edge of the bit the rock is crushed into fine powder, toward the sides of the crater it chips out into relatively large fragments. (Sikarskie & Cheatham, 1973). Singh et al. (1967) investigated the cratering process under the two different conditions of static and dynamic loading. They found that the amount of energy consumed per unit volume of crater is unequal for the two different loading conditions. A complex network of fractures often extends downward and laterally into the rock below the bit. The surface of the specimens showed that the dynamic loading damaged larger area then the static loading."

Jan 1, 1989

By J. W. Paul

This paper deals with the second phase of an extensive research on coal-mine ventilation factors. A comprehensive report of the entire work is in course of preparation, but abstracts of the various chapters are being prepared in order to make the results public as rapidly as possible. Part 1 dealt with the resistance of unobstructed entries and was issued as Serial 2621 of the Bureau of Mines, in July 1924. Description of tests. After the resistance of an unobstructed entry to flow of air had been determined by tests in the Experiment mine, mine cars were; run into the test section in various arrangements and the increase in resistance was determined. The cars used were of the wooden type with loose end gate, and would hold about one ton of coal, level full. They were 7 feet long. 4 feet 2 inches wide above the wheels, 3 feet high, and had a cross-sectional area of approximately 10 square feet. The average area of the entry was about 57 square feet, the ratio of unobstructed to total area being about 17.6 per cent. The track gage was 42 inches and the wheel-base 20 inches.

Jan 1, 1924

By H. C. Ko

As part of the Bureau of Mines effort to provide thermodynamic data for the advancement of mineral technology, the standard enthalpies of formation for ZnO?2ZnSO4 and COS04-6H20 were determined by HC1 acid solution calorimetry. The values are -550.31 ±0.28 and -641.33 ±0.15 kcal/mot, respectively.

Jan 1, 1982

By X. Shi, N. S. Dala, V. Vallaythan

"Cellular damage induced by silica dust is known to be associated with increased fragility and destabilization or destruction of the cell membranes. The mechanism by which silica dust effects biological membranes is still unknown. Using the ESR spin-trap methodology, we find that hydroxyl radicals are generated in aqueous suspensions of freshly ground silica. The amount of the radicals generated depends on the extent of grinding and ""freshness"" of the dust. Using linoleic acid as a model lipid, we show that the silica dust causes lipid peroxidation via ·OH, 02-, or linoleic acid related radicals as intermediates. Catalase and superoxide dismutase inhibit the formation of these radicals. The results suggest that free radicals associated with freshly ground silica and the related lipid peroxidation of the memberanes may be the starting point of the silicotic processes.INTRODUCTIONDespite considerable-effort over the years, the mechanism by which the quartz particles exert their toxic action on cells and the process(es) by which these actions progress to fibrosis are still not fully understood (1,2). It is generally thought, nevertheless, that the interaction of the quartz particles with the cell membranes is the starting point of the silicotic process (3). We felt that the mechanism of the membrane damage by quartz might involve oxygenated free radicals because (a) a suspension of quartz particles in contact with alveolar macrophages has been reported.(4,5) to initiate an enhancement of lipid peroxidation, defined broadly as the ;oxidative deterioration of polyunsaturated components of lipids, and (b) hydroxyl (·OH) radicals are known to be capable of peroxidation by abstracting hydrogen atoms from cell-membrane lipids (6) and initiating lipid peroxidation in lysosomal membranes (7). Moreover it is known that exposure of cell membranes, fatty acids and unsaturated food oils to ionizing radiation, which generates ·OH. radicals, causes rapid peroxidation (6). Earlier studies o~ the aqueous chemistry of quartz suspensions have reported detection of HzOz (8), implicating the formation of ·OH radicals as transient species, but, we are not aware of any report of the detection of ·OH radicals in quartz suspensions and this provided the motivation for the present undertaking. Since it is known that, because of their high reactivity (hence short life time) in aqueous media, the ·OH radicals cannot be detected via electron spin resonance (ESR) directly (9,10), we have used ESR combined with the spin-trap methodology (9) for studying the •OH formation."

Jan 1, 1988

By J. E. Zeilinger

The technical feasibility of using energy from explosive ignitions of coal dust to pump water was .demonstrated in an exploratory investigation. Ignition of small amounts of pulverized coal that were dispersed in air over columns of water pumped up to 5.3 gallons of water per cycle when operated against a head of 30.75 feet. Water displacement was accomplished by either manual or automatic operation through a single cycle, and by automatic operation through a continuous series of cycles of I-minute duration. Operating through single cycles, slurries containing up to 3 pounds of coal and 4.6 gallons of water were also pumped. Possible uses of an efficient coal-fired pump would include pumping water for irrigation purposes, removing water from mines, transporting coal from mines in the form of a slurry, and pumping water to elevated reservoirs at electric powerplants so that it could be used to generate electricity during peak periods of demand.

Jan 1, 1966

By A. E. Wells

"When the United States entered the World War, the heavy requirements for sulphuric acid in the manufacture of explosives made necessary a definite knowledge of the sulphuric acid capacity of the country. The Bureau of Mines, under the authority conferred by the explosives regulation act, made a thorough survey of the sulphuric acid situation. In this work, which was personally directed by the writer, comprehensive data were collected on the situation and capacities of the various acid plants, sources of supply of raw materials (brimstone, pyrite, pyrrohotite, zinc ores and concentrates, waste sulphur dioxide gases from copper smelting, and spent oxide from gas works), the principal points in regard to manufacturing processes (chamber and contact) and the uses of the acid. The results of this investigaion have recently been published by the Bureau of Mines, as Bulletin 184, entitled ""The Manufacture of Sulphuric Acid in the United States"" by A. E. Wells and D. E. Fogg. The following paragraphs on the uses of sulphuric acid are abstracted from this bulletin.Sulphuric acid is one of the most important of all chemicals, not only because of the large quantities manufactured but also because of the wide use of the acid in many different industrial works. Sulphuric acid is to the chemical industry what iron is to metallurgy. The general public, however, does not realize this fact, for sulphuric acid does not appear in the finished product as does iron and steel, but is only a means to an end. It is essential in many industries, such for example as in the manufacture of phosphate fertilizers, explosives, dyes and petroleum products. In recent years in the United States, especially in the East, the demand for sulphuric acid for chemical and metallurgical industries has been an accurate and sensitive barometer of the general business conditions. This demand for acid responds much more quickly to a general slump or boom in the industrial world than does the demand for iron and steel."

Oct 1, 1920

By P. L. Swanson

Over a recent 20-month observation period, the U.S. Bureau of Mines obtained seismogram records from a single vertical-component, short-period seismometer installed at the surface of a metal mine in northern Idaho. The seismic events were analyzed for local (Richter) magnitude (M), time of occurrence, location, and relation to rock bursting and production blasting. Approximately 150 seismic events with -0.5 = M = 2.9 were located within the mine, yielding a b value (slope of the logarithm of the number of events with magnitude greater than M versus M) of 0.5. Event locations were constrained using a dense underground array of high-frequency accelerometers. Twenty of the surface-recorded events, with 0.5 = M = 2.9, were associated with rock bursts that produced damage requiring at least 1/2 day of cleanup and/or repair. Other possibly hazardous rock bursts, with magnitudes as small as -1.1, were numerous but were not associated with significant structural damage. Approximately 60 pct of the seismic events with M > -0.5 and 75 pct of damaging rock bursts occurred within 45 min of blasting. Estimates of characteristic rupture dimensions for rock bursts with -1.1 = M = 2.9, based on a conventional dislocation shear-slip model of failure, range from 3 to 300 m.

Jan 1, 2010

By D. G. Kuehn

Studies were conducted by the Bureau of Mines to determine the positive ions and neutral species produced in glow discharges of gas streams containing 1.0 percent NO in helium, 29 percent dry air in helium, and 1.06 percent NO in N2, Mass spectrographic measurements were conducted for gas pressures from 2.3 to 10.0 torr and dc currents from 10 to 20 mAo Ion species observed included NO+, N2 +, O2 +, N+, and 0+ with lesser amounts of He+, He2+, and N02+. Variations in various ionic and neutral species with discharge duration were interpreted to be consistent with an electrically induced dissociation of NO to produce N2 and O2. No nitrogen oxides were observed to form in glow discharges of the helium-air mixture.

Jan 1, 1975

By J. P. Barkley

"The accompanying tabulation gives the results of a series of operating tests on two types of small stokers. One was an inclined, natural-draft, moving-grate, overfeed ""hand-stoker"" fired and manipulated by hand; the other was. a horizontal, forced-draft, stationary-grate, underfeed, mechanical unit-stoker operated by an electric motor. These were installed as shown by the accompanying sketches (figs. 1 and 2) under horizontal return tubular boilers of a nominal rating of 150 bl.h.p. each.The steam load carried by these boilers was a rather typical heating load. It was fairly constant and of about 30 bl.h.p. throughout the summer months, with small variation between day and night. During the winter months the daily variations were dependent upon the outside temperature. The boilers were banked a considerable part of the night.As noted in the table, two kinds of coal were used. The size of one kind was run-of-mine and the other 11/4 inch nut and clack. These coals from two different mines of the New River district both caked considerably during burning, the nut and slack more than the other. Analyses of the coal were as follows:"

Jun 1, 1929