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The results of a Feasibility and Design Study of Surface Impregnation Equipment to be used for Chemical Stabilization of Coal Mine Structures are described in this report. The study was sponsored by the United States Department of the Interior, Bureau of Mines, under Contract H0210055. This program was undertaken as an essential part of the Bureau of Mines Chemical Ground Stabilization Program. The responsible prime contractor was The Eimco Tunneling and Mining Machinery Division of the Envirotech Corporation. The Rocketdyne Division of the North American Rockwell Corporation performed part of the feasibility study and design and testing of the metering and feed system as a subcontractor to Eimco.

Jan 1, 1972

By Jr. Driscoll

The thermoelectric properties of yttrium monoarsenide, yttrium monoanti-monide) and ternary materials from the Y-As-Se and Y-Sb-Te systems were investigated by the Bureau of Mines from room temperature to 1,000° C. The maximum calculated figure of merit for yttrium monoarsenide and yttrium monoantimonide was 2 x 10-5 ° C-1. YAs and YSb were semimetallic conductors with low Seebeck coefficients and electrical resistivities. The values of the Seebeck coefficient and electrical resistivity of the Y-As-Se and Y-Sb-Te materials were between those of the yttrium selenides and tellurides and of YAs and YSb, respectively. The maximum power factor calculated for the Y-As-Se materials was 2 X 10-5 watt/cm ° C2 which yielded an estimated figure of merit of 6 X 10-4 0 C-1. Most of the Y-As-Se compounds had high Seebeck coefficients and moderately low electrical resistivities. The Y-Sb-Te materials were degenerate semiconductors with power factors of 6 X 10-8 watt/cm ° C2.

Jan 1, 1967

By F. E. Griffith

Cost data are given for five methods of secondary backfilling of strip mines previously partially backfilled. The operations were conducted in north-central Pennsylvania; an average of 600 linear feet of highwall were backfilled in each trial. Major obstacles and the relative merits of the methods are discussed.

Jan 1, 1966

By R. Barany

The heats of the glass-crystal transformation of nepheline (Na0.7794K0.2206AlSiO4) and wollastonite (CaSiO3) and the heat of formation of nepheline at 298.15° K were determined by solution calorimetry. For the glass-crystal transformations, the heat values were -9.0 ± 0.3 kcal/mole for nepheline and -8.1 ± 0.2 kcal/mole for wollastonite. The heat of formation of nepheline was -34.8 ± 0.6 kcal/mole from the oxides and -501.0 ± 0.5 kcal/mole from the elements.

Jan 1, 1966

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

By McHenry Mosier

This paper describes come mechanical raid electrical signal systems in common use in Metal-mine shafts, together with several distinctive systems that indicate or control the origin of the signal. The latter systems remove the hazard of the movement of the cage from one level in response to signals from another. Previous publications of the Bureau of Mines have covered several meritorious installations One of the best signal systems for deep shafts is at the Homestake mine4/. A successful installation of an induction system in the Lake Superior mining region permits signaling as well as telephoning from cages at rest or in motion5/. El Potosi mine uses a variation of the three-wire electric system6/. A mine in Utah has developed a system of the double trolly-wire type, in which the cage attendant may signal from a moving cage7/. At present no system of the sine-shaft signaling employing radio is available.

Jan 1, 1939

By W. E. Young

This paper describes operations of the Chief Consolidated Mining Co. at the Chief mine in the Tintic district, Juab County, Utah, where the outstanding problem is water control; the unique pumping methods employed are featured in this report. The ore bodies in this district occur as long, narrow shoots along fault fissures, usually in the Bluebell dolomite of Ordovician age. Oxide ores predominate above the 1800 level, which is also the natural water level. Sulfide ores containing lead, zinc, silver, and gold extend below the 1800 level. The mine is developed by vertical shafts and winzes, from which drifts are driven to the ore bodies. In the lower levels of the mine these drifts extend long distances from the shafts or winzes because of the relatively low dip of the ore shoots. The mine has been worked to the 2800 level and the 18-411 winze extends to the 3080 level.

Jan 1, 1958

By Irving Hartmann

Modern mechanized mining with high-speed machines, multiple-entry systems, multiple blasting, high-velocity air currents, and rapid haulage has brought many economic benefits and has on the whole enhanced safety in the coal-mining industry. It has, however, also introduced some added hazards, the control of which requires concerted effort and ingenuity. Mechanized mining has greatly increased the production and dissemination of fine coal seam or in mine entries. Use of high-speed machines has increased the probability of formation of incendive sparks, which are produced by frictional contact between moving metals and certain mineral substances in the coal seam or in the adjoining rock strata. In gassy seams rapid extraction of coal has increased the rate of gas evolution. These facts have made more urgent the need of preventing the ignition of coal dust and the development of widespread mine explosions. The ignition hazard can be controlled best by eliminating all potential igniting sources and by careful attention to ventilation designed to prevent accumulation of gas capable of triggering a coal-dust explosion. Frictional spark ignition by mining machines and suggested safeguards are discussed in a recent publication. Extensive research and long experience have shown conclusively that the propagation of coal-dust flames can be arrested and the development of widespread explosions prevented by properly applied, generalized rock dusting.

Jan 1, 1956

By Frank E. Cash, Max S. Petersen

"INTRODUCTION Explosives have been used in ever—increasing amounts since gunpowder was invented. For hundreds of years only low explosives of the deflagrating type were used, and they were fired by means of a flame or hot object. Ben¬jamin Franklin first ignited gunpowder from a distance in 1751 by means of an electrostatic spark. Further efforts to develop a satisfactory electrical method to ignite explosives from greater distances were overshadowed by the invention of safety fuse in 1831, as this offered a relatively simple and inexpensive means of firing explosives.The discovery and introduction of high explosives of the detonating type and the invention of the fulmitate of mercury blasting cap about the middle of the nineteenth century provided the needed impetus for inventors to develop means of firing the cap by electricity. The original high-tension igniter, following Benjamin Franklin's experiment in which the detonating compound was ignited by a spark, was discarded in favor of a low-tension igniter, in which the detonating compound was ignited by a heated wire. The past 2 decades have seen considerable improvement in the design and construction of electric detonators to make them safer and more efficient, yet in spite of the improvement it is estimated that less than 50 percent of the explosives used in industry today are ignited or detonated electrically. The trend, however, is toward the use of electric methods. In recent years numerous-mining companies have introduced electric blasting exclusively at their mines as a means of improving safety and efficiency."

Sep 1, 1946

By A. C. Fieldner

"Purpose and Nature of Tests:The rapidly increasing use of motor vehicles and trucks in the United States is creating an entirely new problem in the proper ventilation of tunnels, subways and other confined spaces through which such machines must pass. This problem has become of immediate importance because a tunnel 3,000 ft. long is being designed to pass under the Hudson River between New York City and New Jersey. Another tunnel at Pittsburgh 5,700 ft. long through the South Hills, is already under construction, and a third tunnel, 6,000 ft. between Boston and Past Boston is proposed. It is probably that other tunnels will be started in various parts of the United States in the near future.The ventilation of such tunnels is a serious matter, on account of the poisonous nature of automobile exhaust gases. It not uncommon to read about finding a man dead in his garage. Generally this happens on a cold, winter morning, after he has been running the engine with the doors and windows closed."

Mar 1, 1920

By Th. G. Sahama

This paper contains some new heat-of-solution measurements of geikielite (MgTiO3), limonite (FeTiO3), fayalite (Fe2SiO4), and a natural forsterite in mixed acid (HF +HCl) and gives the results of a thermodynamic attack on the problem of stability of geikielite in rocks.

Jan 1, 1949

By Alan G. Mayton

The Bureau of Mines conducted a study to (1) determine from laboratory tests the feasibility of a photographic method for determining reflec-tances that may be applied to measuring in-mine mineral reflectances and (2) formulate a procedure for collecting and analyzing the data. The method uses a 35-mm camera with automatic flash and a gray-scale re-flectance standard to collect on film the reflectivity data in under-ground mineral mines. After the film is processed, the data on the photographic prints are analyzed in the laboratory with a photometer. Test results show the photographic method can provide values of reflec-tance to within ±5 pet of full scale (full scale = 100 pet). The method's usefulness for determining reflectivity values, within similar limits of absolute percent error at the lower end of the scale, however, has not been completely resolved by the study and consequently warrants further investigation. The method offers an acceptable means for collecting and analyzing reflectivity data for reflectivities at the higher end of the scale, i.e., 50 pet or above; it should be used with caution when reflectivity values are below 50 pet. Four films were evaluated; all gave relatively satisfactory results.

Jan 1, 1987

By Sidney Katell

Several systems have been proposed for the production of synthetic crude oil from oil shale. An economic analysis of one proposed system is presented in this paper. An oil shale complex to produce 100,000 barrels per calendar day of semirefined crude oil will require a capital investment of $426,216,400. This investment includes mining, retorting, intermediate pipelining, and partial refining. A selling price of $3.74 per barrel of product will be necessary to maintain a discounted cash-flow rate of 12 percent.

Jan 1, 1971

By J. A. Lamonica

The Bureau of Mines studied two types of approved coal mine dust personal samplers to determine the effect of decreasing the amplitude of airflow velocity fluctuations on cyclone performance. Results indicate that more dust is collected when pulsation free flow is used. Velocity fluctuations were reduced by means of a pulsation damper; damper efficiency of about 85 percent was needed to reduce the fluctuations to an acceptable level. The data were obtained employing both pulsating and non-pulsating flow. A comparison was made of (1) the masses of respirable coal dust as determined by weighing and of (2) the particle size distributions as determined by an electronic counter. An empirical relationship is given between the ratio of masses collected using pulsating and nonpulsating flow (M') and the ratio of the maximum air velocity to the minimum air velocity (V') as measured in the cyclone entrance channel.

Jan 1, 1972

By S. H. Katz

Artisans and laborers in mineral industries where the air is dusty with particles of reel: are subject to a peculiar pulmonary disease known as miners' phthisis or stone cutters' consumption. In granite cutters the disease is specifically designated as granite pneumoconiosis. Very fine particles of the harder rocks are especially injurious when inhaled into the lungs. It is estimated particles about one micron (1/23000 part of an inch in diameter) are most injurious, because larger particles are more readily removed by the cilia and,wet surfaces of the respiratory passages before reaching the lungs, while smaller particles either do not readily lodge or are more easily eliminated. Silica, of which quartz and flint are composed, and which forms a large part of granite, is one of the hardest of the common rock-forming materials. It is also very insoluble when silica lodges in the lungs elimination is difficult. Rock constituents of granite other than silica are probably injurious but in a lesser degree, and this is also probably true of limestone and the softer rocks. Ultimately a worker who daily inhales much granite dust has considerable deposited in his lungs. If he continues at his trade the lung tissue becomes harder and less elastic, he finds himself short winded, and in extreme cases death may come either directly or indirectly as a result of lung failure.

Feb 1, 1921

By Edward P. Barrett

This investigation was a part of the Bureau of Mines program for the production of critical and essential materials needed for the war. The Boykin Committee for investigating the steel shortage aided in obtaining an appropriation to be expended by the Bureau of Mines in studying the utilization of North Dakota lignite in the manufacture of hydrogen that could be used in the production of sponge iron from the low-grade iron ores of Minnesota. This investigation was conducted by the Bureau of Mines to determine the workability of the proposed shaft-furnace process and its possible use in connection with an experimental plant for the gasification of lignite operated by the Coal Division of the Bureau of Mines at Grand Forks, N. Dak.

Jan 1, 1948

By A. Wahab Khair, N. P. Reddy

"Abstract. This paper attempts to characterize coal breakage due to the action of a continuous miner. Coal blocks with an approximate dimension of 45.7 cm x 38.1 cm x 15.2 cm (18 in. x 15 in. x 6 in.) were first subjected to confining pressures equivalent to in-situ conditions. Then the blocks were cut along the face/butt cleat direction by the cutting head of a specially designed unique automated rotary coal cutting simulator (ARCCS), simulating the action of the continuous miner in underground coal mining. During the tests under a particular set of in-sit and operating parameters a number of other para¬meters such as 1) penetration of bit into coal, 2) penetration resistance (thrust and cutting pressures), 3) rotating velocity of cutting head, and 4) acoustic emission activity in the coal block were monitored. After each cutting cycle the fractured surfaces were photographed and a velocity survey was conducted by using a sonic technique. At the end of each experiment, the coal fragments were collected in bags using a vacuum cleaner. These fragments were then sieved for size distribution analysis.INTRODUCTIONThe Federal Coal Mine Health and Safety Act of 1969 was enacted to emphasize to coal operators that the airborne respirable dust should not exceed 2 mg/m3, thus reducing the incidence of coal workers pneumoconiosis.Dust control techniques such as conventional water sprays and dust collectors are only partially effective and require additional equipment expenditures. A more authentic approach would be to reduce respirable dust at the source the continuous mining machine cutting head, where the fragmentation process occurs. Improving the fragmentation process by characterizing the coal breakage will not only reduce respirable dust at the face, but it will also decrease the amount of respirable dust that is liberated during the secondary handling.Fragmentation of coal can be expressed as a function of three major groups of parameters; namely, 1) coal properties, 2) in-situ conditions and 3) operating parameters. This paper deals with the characterization of coal breakage along both face/butt cleat direction as a function of machine operating parameters such as rate of advance, angle of attack, bit configuration, bit lacing (spacing and pattern) and bit speed at various equivalent in-situ pressures."

Mar 1, 1989

By A. H. Warner

Sphalerite crystals occur sparingly in minor faults and pockets in a coarsely crystalline dolomite on the Brown-Tipton farm near Greenville in Greene County, Tenn. After several visits by U. S. Bureau of Mines engineers and U.S. Geological Survey geologists, a survey was r: the in the fall of 1944. Upon their recommendations, trenches on the Brown farm under Bureau of Mines supervision. In each case, the bed most favorable for zinc deposition was exposed. In the finished trench bottoms no zinc minerals are visible.

Jan 1, 1950

By E. D. Gardner

"A fire hazard exists in nearly all mines. Progressive mining companies recognize this danger and take all possible precautions to prevent any conflagrations, but in spite of such safety measures, mine fires do occasionally occur and endanger life and property. In order to be prepared for such an emergency, miners are trained in the use of self-contained breathing apparatus and the necessary fire-fighting equipment is kept on hand. Men trained to wear breathing apparatus can penetrate workings full of poisonous fumes, but in order to successfully combat fumes or to rescue miners, the rescue crews must be trained in fire-fighting operations and know how to proceed with a minimum loss of time when they get to the scene of action.In order to perfect fire-fighting plans and to train men of the Globe-Miami district under conditions approximating those found at an actual mine fire, mine-reseue maneuvers were held at Globe, Arizona, on October 17-20, inclusive. The work was done under the direction of Orr Woodburn, director, and his associates of the Globe-Miami District Mine Rescue and First Aid Association. He was assisted by Albert Tallon, safety engineer, and Herbert Finnegan of the Old Dominion Co.; Herbert Hodson, safety engineer for the Inspiration Consolidated Copper Co.; A. 3. Martinson and J. M. Harrington of Car One, and F. D. Gardner of the Southwest Station, Bureau of Mines. Invitations were issued to mining men likely to be interested and representatives of mining companies from other districts were present and observed the work.The Globe-Miami District Mine Rescue and First Aid Association is maintained by the mining companies in the district and each company contributes to the organization's support in proportion to the total number of men on the pay roll. A central station*, between Globe and Miami, has been established and a truck with 10 sets of 2-hour self-contained breathing apparatus and the necessary accessories is always in readiness to respond to a call to any of the mines in the district. Besides being in readiness for emergency work, the station employees train men in the use of mine-rescue apparatus and in first-aid to the injured at the mines of the association. The Globe-Miami Mine Rescue organization has been developed to high point of, efficiency under Mr. Woodburn's direction and is one of the best in the country. The three largest mines of the district such maintain a crew of 15 men trained in the use of breathing apparatus, and other mines keep crews of 5 men each."

May 1, 1923

By M. A. Schellhardt

"INTRODUCTION The augmented demands for natural gas in many parts of the United States as a result of war have increased the need for information regarding the producing characteristics of natural-gas and gas-condensate-type wells capable of delivering large volumes of gas, as such information is important to the formulation of conservative and efficient operative and recovery practices.,For many years, the capacity of natural-gas wells to produce gas has received studied consideration by Bureau of Mines' engineers, and three reports 3/ on gaging gas-well capacities have been published. In Report of Investigations 2929, Pierce and Rawlins point out that for accurate gaging, the actual pressures at the face of the sand in the well and the relationship between such pressures and the rates of flow of gas through the sand must be determined. Their report describes a method of attacking the problem of determining the actual pressures at the sand by means of observations of pressures and volumes at the wellhead.In Report of Investigations 2930, Pierce and Rawlins explain how the fundamental relation"

Aug 1, 1944