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By Lewis C. Karrick

This paper is based on data obtained in the course of the oil - shale investigations of the U. S. Bureau of Mines , conducted in cooperation with the State of Utah . The amount and quality of oil that can be produced from any shale may be made to vary to an important degree by changing the temperature relations existing in the shale charge during destructive distillation . The rate at which the oil is formed from the shale is affected by the rate of heat supply , and therefore by the temperature of the shale during its thermal de composition . The quality of the oil formed may be controlled by altering the temperature of the shale , and therefore , the rate of formation of the oil . Variations in the yield and quality of shale oils may be caused by inherent properties of the retort used , but in any event the properties of the crude oil and yield are very largely the result of the extent to which the thermal de composition has progressed . Recognition of these principles will aid in explaining to a large degree the reasons for the wide variations in oils produced from the same shales by different " processes " . These principles also may be applied in the operation of different types of retorts in order that crude oils of a type most profitable to the operator may be produced . The Bureau of Mines has conducted an extended series of tests in the dee structive distillation of oil shales , in order to determine the wide variations that may be effected in the quality and yield of shale oil by changing the rate and temperature at which the oil is formed . These tests furnished interesting information on the four related points : yield of oil , quality of oil , temperatures required to distill shales , and time required for distillation .

Mar 1, 1923

By John C. Machisak

THIS CHAPTER reports employment data and injury experience in the metal, nonmetal, quarrying, sand and gravel, and slag (iron blast furnace) industries of the United States in 1959. Each industry is treated separately, and no attempt has been made to combine data to show an overall total for this group of mineral industries. The slag canvass is included for the first time (data on employment and injuries were not collected before 1958), and, like other canvasses included in this chapter, data are voluntary. Employment and injury experience for all mineral industries can be found in volume III. The employment and injury information in this chapter came from reports submitted to the Bureau of Mines before May 31, 1960; therefore, figures are preliminary and subject to revision. Voluntary reports submitted by operators have contributed substantially to safety promotion since 1911, when the Federal Bureau of Mines started collecting employment and injury facts.

Jan 1, 1960

By W. E. Wallace, C. A. Hill, M. J. Keane

"Diesel exhaust particulate material from exhaust pipe scrapings of two trucks, diluted automobile diesel exhaust particulate material collected on filters, and two oil shale ores were prepared for the Ames mutagenrcity assay by dichloromethane OOP ex¬traction, by dispersion into 0.85% saline, or by dispersion into dipalmitoyl lecithin (DPL) emulsion in saline. Salmonella typhimunum TA98 was used to detect frameshift mutagens in the samples. Samples of diesel soot gave positive mutagenic responses with both DCM extraction and DPL dispersion, with the DPL dispersion giving higher results in some cases. The results suggest that possible mutagens associated with inhaled particles may be dispersed or solubilized into the phospholipid component of pulmonary surfactant and become active in such a phase.INTRODUCTIONThe Ames Salmonella/microsome assay (Ames et al., 1975) has been shown to be a useful test for detecting genotoxic properties of various agents. Hundreds of specific chemicals have been screened (McCann et al., 1975), and the test has been applied for many types of environmental samples. Airborne mutagenic agents, for example, have been found in urban air (Chrisp and Fisher, 1980; Hughes et al., 1980; Ro· senkranz et al., 1978), in diesel engine exhausts (Huisingh et al., 1978), and in the by-products of coal combustion processes (Chrisp et al., 1978).Samples of airborne particles are typically collected on membrane filters, and undergo a rigorous extraction procedure with organic solvents and/or ultrasonic agitation (Clark and Hobbs, 1980). Often extracts are transferred to another solvent that is compatible with the assay system. These extraction procedures, while efficient from an analytical perspective, are not physiologically plausible. The questions that present themselves are whether a demonstrated mutagen can be taken up in vivo and whether the process is quantitatively or qualitatively different from the above laboratory procedure (Wallace et al., 1984).When a particle of respirable size is inhaled to the alveolar region of the lung, its first physiological contact is with pulmonary surfactant that lines the inner surfaces of the alveoli. This surfactant is an aqueous fluid containing proteins, phospholipids, and other components (R. J. King, 1982). The principal phospholipid constituent is L·alpha-phosphatidylcholine, beta,gamma-dipalmitoyl, or dipalmitoyl lecithin (OPL) (l. C. King et al., 1981)."

Jan 1, 1989

By Charles W. Huggins

The Bureau of Mines investigated palygorskite, a natural asbestiform material, to accumulate knowledge that might serve as a foundation for future synthesis of a similar material. Unit cell, chemical analysis, DTA, TGA, optical constants, and electron microscopy data were obtained. Selected palygorskite samples of bettor than 97-percent purity were used to obtain this information. Chemical analysis revealed the following formula: (OH2)4 (OH)2 Ca0.01Fe0.02K0 .c3Mg2.10A12.00Si7.93020.3.91 H2O. The optical constants for sodium light are a = 1.522; S = 1.530; ?=1.533; biaxially (-). The following orthorhomibic unit cell constants were determined: ao = 12.690 A, Z = 2, bo = 17.857 A, Dx = 2.327. co = 5.207 A, Identical diffraction patterns resulted from the three palygorskite samples that were studied. X-ray, chemical, DTA, TGA, and optical data were compared with literature values for similar fibrous materials. X-ray diffraction lines were indexed. Several electron micrographs were made to compare the structures of palygorskite and attapulgite with that of chrysotile. The micrographs revealed extremely short laths for attapulgite, very long flexible laths for palygorskite, and tubular structure for chrysotile.

Jan 1, 1962

By M. D. Schlesinger

Mercury exists in coal at very low levels; the structure of coal, the vapor pressure of mercury, and its almost universal occurrence introduce unusual problems into the analytical methods. Round-robin analyses by several laboratories, each using its own techniques, indicate that the average mercury content of coal is about 0.2 part per million. Some western coals are as low as 0.05 ppm.

Jan 1, 1971

By Harry E. Tuff

"This paper is based data obtained by the Bureau of Mines from some of the principal mine operators in Pennsylvania, in the course of a study conducted in cooperation with the U. S. Forest Service, with regard to economies that might be effected in the selection storage, and preparations of timber particularly treatment with preservative to prolong its life.The Pennsylvania anthracite region, considered as a single mining district is by far the largest user of mine timber of any mining district, either coal or metal, in the United States, and the bituminous districts of Pennsylvania rank second. The present annual consumption of mine timber by the coal-mining industry of Pennsylvania probably exceeds 100,000,000 cubic feet annually.In 1919, Pennsylvania produced, in round figures, 145,300,000 tons of bituminous coal, 86,200,000 tons of anthracite, and 5,400,000 tons of iron ores. If it be assumed that the bituminous coal mines required 0.33 cubic feet, anthracite mines 0.7, and iron mines 0.9 cubic feet per ton mined the timber requirements were bituminous. 47,950,000; anthracite, 60,340,000; iron mines, 4,860,000 or a total of over 113,000,000 cubic feet.The average cost of round mine timber in the anthracite region in 1905, was, according to the U. S. Forest Service, 6.6 cents per cubic foot, and $15.00 per 1000 board feet for sawed timber. The present cost Las advanced to 27.5 cents per cubic foot for round timber, delivered to the mine, of which cost 57.4, represents freight charges."

Nov 1, 1923

By James V. Luxner

The airflow and methane distribution patterns developed in an equipment-free entry 6.5 feet high and 12 feet wide, ventilated by line brattice operated blowing to or exhausting from the face, were determined by the Bureau of Mines for varying conditions. Results of these studies show that blowing line brattice systems of face ventilation are more effective than comparable exhaust systems. The face ventilating efficiency of any line brattice system is dependent upon the method of ventilation, the face distance, the tight rib distance, the volume of air delivered to the end of the line brattice, and the volume of methane released at the face. Experimental results indicate that maximum face ventilation efficiency is achieved when the inby terminus of the line brattice is installed 5 feet from the face and at a distance less than one-third the entry width from the nearest rib. Analyses of data are based upon the ability of a face ventilation system to dilute methane in the immediate face area.

Jan 1, 1969

By L. E. Dalverny

This Bureau of Mines report describes the deployment, 5-month operation, and lessons gained from a continuous gas monitoring system using sampling-tube bundles at an underground mine fire in West Virginia. Research information gained indicates the utility of relating certain gas concentration ratios to events during fire development, mine reventilation, and mine recovery. In addition to monitoring the quality of remote fly ash seals, the system provided timely warning of dangerous gas concentrations which developed during surface and underground recovery activities. An evaluation of system components is supplemented by recommendations for improvements.

Jan 1, 1975

By W. G. Bradley

THIS PAPER describing the quarrying, mining, and crushing of gypsum at the Blue Diamond mine, 11 miles from Arden, Nev., on the Union Pacific Railway, is one of a series on gypsum mining being prepared for and published by the Bureau of Mines. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total costs. It is recognized that publication of total production costs might in some instances cause embarrassment to individual producers as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue.

Jan 1, 1932

By Murray Jacobson

The respirable dust standard in the Federal Coal Mine Health and Safety Act of 1969 is designed to prevent disability and death from coal workers' pneumoconiosis. Beginning June 30, 1970, the operators of coal mines were required to maintain the average concentration of respirable dust in the active workings at or below 3.0 milligrams of dust per cubic meter of air. The standard is reduced to 2.0 milligrams per cubic meter after Dec. 30, 1972. This paper presents the equipment and procedures used by the coal mine operators in implementing the respirable dust sampling program established by the Secretary of the Interior and the Secretary of Health, Education, and Welfare and shows the effect of the law, during the first year, on the reduction of dust levels in selected mines. The system employed by the Bureau of Mines for analyzing and processing the dust samples is also presented.

Jan 1, 1971

By H. B. Freaman, C. L. Colburn, C. M. Bouton

"The mine telephone has been perfected to such an extent that it is giving satisfaction in most mines were the wiring is well insulated. Very often the telephone cannot be depended upon on account of falls of rock, grounding due to worn insulation or extreme dampness. In the event of a disaster it frequently happens that the mine telephone system is put out of commission by the agency that causes the disaster, at the time when it is most urgently needed. On this account the mining industry is interested in any kind of telephone system that can be counted upon in an emergency. Many requests have been received by the Bureau of Mines to devise means of utilizing wireless methods for this purpose.The results of some preliminary experiments conducted by the writers at the Bureau of Mines experimental mine at Bruceton, Pennsylvania, in the ordinary sending and receiving of radio waves through earth strata are described below. The experiments were made in cooperation with the Westinghouse Electric end Manufacturing Co., which assigned to this work three of its radio engineers, C. A, Boddie, E. C. Douglas, and F. D. Fessler,The preliminary experiments consisted first in receiving signals from without the mine by means of a receiver located inside the mina, and second, both sending and receiving messages underground through the strata. It was found that with a receiving instrument set at a point 100 feet underground, signals from KDKA station, of the Westinghouse Electric and Manufacturing Co. East Pittsburgh, Pa., could be heard distinctly. Station KDKA is at a distance of about 18 miles from the experimental mine. About 50 feet from the receiving station used in this test was a 6-inch bore-hole from the surface, lined with iron pipe and containing electric light wires which extended therefrom through-out the mine. The presence of these wires evidently assisted greatly in the reception, for when the receiving set was carried to another point in the mine removed from wires and tracks the signals were barely audible through 50 feet of cover. The fact that signals were detected, however, even though faintly, is sufficient evidence of transmission through the ground to encourage further experimenting.In sending waves underground the Westinghouse 20-watt B.T. model T.F. transmitter was used in such a manner as to send out continuous waves of 200 to 300 meters length."

Oct 1, 1922

By M. J. Dailey

This paper is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. The property of the Silver King Coalition Mines Co. is situated in the western past of the Park City mining district, Utah, about 1 ½ miles southwest of the town of Park City, The elevation at the collar of the main shaft is 8,137 feet above sea-level.

Jan 1, 1930

By C. W. JEFFERS

During the past few years the use of mechanical equipment for the loading and transportation of coal at the working face has rapidly increased . Many mining officials are of the opinion that mechanical methods have tended to reduce the hazards of mining, and a number of statements have been made to this effect . Little actual data upon which to base conclusions in regard to the relative safety of various methods of mining have been made available . While it may be possible that these systems of mechanical mining are inherently less hazardous , obvious dangers should not be disregarded in the belief that the mere act of installing mechanical loading equipment automatically brings about better accident records . The same rules and regulations , modified to meet the new regime must be applied with the same discipline as heretofore . By diligent study and application there is reason to believe that new methods of concentrated mining can be utilized with at least a possibility of increased accident performance . With the idea of preventing accidents by taking available precautions against their occurrence , attention should be directed to the dangers that exist where room and face conveyors are in operation . Due to the cost pressure prevalent in the mining industry at the present time mechanical means are often used in an attempt to decrease cost of production. The management , after having spent considerable sums of money for new equipment , is expected by stockholders and investors to show results by increasing tonnage and reducing operating costs . Consequently the operating officials apply the same pressure to local mine officials to obtain results . The natural reaction of the superintendent and mine foreman is to secure the maximum production from the new method , and unfortunately safety is frequently , if not generally , sacrificed to this end . In many instances , operators of new types of mechanical loaders are difficult to secure and after being obtained are difficult to hold , especially if the new equipment is more or less in the experimental stage . The tendency is to handle the machine operators with " gloved hands " and to permit many unsafe practices which ordinarily would not be allowed, in order to keep from antagonizing them and losing their services . Although these unsafe practices become habitual and even uneconomical , conditions thus established are difficult , sometimes impossible , to change .

Jul 1, 1930

By D. A. Paice, A. B. Shimp

Illegitimate loads on a mine dc power distribution system can be detected by measuring a superimposed ac current. To implement such a scheme, a 10-volt, 3-kHz voltage is applied at each dc power substation. By this means, the mine dc power distribution network, consisting of a feeder and trolley wires with a grounded rail return, is caused to serve also as a 3-kHz ac distribution network.

Jan 1, 1975

By H. H. Schrenk

The safe use of a refrigerant or any substance depends on knowledge of its pertinent properties and conditions of use; therefore some of the properties of refrigerants that are related to life, fire, and explosion hazards are discussed herein. These data serve as a basis for suggested control measures in the use· of refrigerants. The properties of refrigerants may be broadly classified into three main groups: (1) Those important for refrigeration, (2) those significant from the standpoint of confining the refrigerant, and (3) those that become important if the refrigerant escapes from the :machine or container. The first group of properties, such as latent heat of vaporization, specific heat of vapor, specific heat of liquid, etc., is not considered to be directly related to safety and is not discussed here. The second group, those properties important in confining the refrigerants, has particular significance because· it relates to "built-in" safety. This group is emphasized because it is believed the soundest procedure in designing equipment is to give due consideration .to both the health and safety hazards likely to be associated with the equipment. Furthermore, the toxicity, fire, and explosion hazards are controlled as long as the refrigerant is confined. Some properties of this group are (1) stability, (2) corrosiveness, (3) boiling point, (4) pressure developed in the system, (5) warning odor or irritation, and (6) ease of detection. The third group includes such properties as toxicity (of compound and decomposition products), irritating action, and explosibility.

Feb 1, 1942

By Thomas E. Popplewell

This paper is one of a series being prepared for and published by the United States Bureau of Mines describing the mining and treatment methods and costs obtained in sand and gravel plants throughout the United States. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total costs. It is recognized that publication of total costs might in many instances cause embarrassment to individual operators as well as to the industry as a whole. On the other hand operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue.

Jan 1, 1932

By D. Harrington

An explosive may be defined as a substance (usually a mixture) that has the property of yielding, readily to combustion or oxidation upon application of flame or shock, the combustion or oxidation process being rapid and accompanied by formation of such relatively large quantities of gases that much violence and pressure are produced; these, in turn, react against their surroundings and cause what is termed an explosion. By their very nature their action is destructive and disruptive of adjunct materials; hence, all explosives axe potentially hazardous and every type of explosive, irrespective of its relative safety, should be handled, .stored, and used with utmost care at all times and under all conditions. It should always be remembered that any explosive can be rude safe only in certain of its features and under certain conditions and circumstance. If these facts (and they certainly are facts) are always kept in mind, most of the modern types of explosives can be utilized advantageously in our industrial life and with a considerable degree of safety. That commercial explosives can be handled. safely is borne out in part by the fact that in the past 15 years at least 3,000,000,000 pounds of the commercial explosive dynamite have been transported by railroads in the United State, without injury to any person, insofar as available records indicate.

Jan 1, 1939

By Alton B. Cook

Equipment has been designed and fabricated for study of the vaporization of oil during gas-cycling operations, A sand-packed steel tube, which can be rotated to minimize gravity drainage, is used as a model oil reservoir. A minute windowed cell at the discharge end of the tube through which the liquid-gas interface may be observed, makes possible the separate removal of produced free gas and gas-saturated oil. The operation of the model oil reservoir, and auxiliary equipment, are described by use of a schmatic flow diagram. Details of the specially designed equipment are illustrated by isometric and pictorial drawings, and a description of the experimental procedure is given.

Jan 1, 1959

By K. O. Bennington

The thermodynamic properties of pollucite [(Cs0.650Na0.185Rb0.028)(AlSi2) (05.8630H0.137)?0.19H201 were determined by the Bureau of Mines in collaboration with the Argonne National Laboratory. The standard enthalpy of formation determined by hydrofluoric acid calorimetry is ?Hf°298 = -3,098.52 ±3.63 kJ mol-1. The standard enthalpy of formation from the oxides is ?H298 (from oxides) = -209.50 ±2.38 kJ mol-1. Low-temperature heat capacities were determined by adiabatic calorimetry from 5.0 to 306.1 K. The derived standard entropy is S°298 = 207.24 ±0.43 J mol-1k-1. Enthalpy increments above 300 K were measured by copper-block drop calorimetry from 349 to 674 K. Various experimental data were combined with other data from the literature to calculate the Gibbs energies of formation and equilibrium constants of formation over the temperature range of measurements. Standard enthalpies of formation and Gibbs energies of formation are given as functions of temperature. The Gibbs energy of formation is ?Gf°298 = -2,919.9 W mol-1

Jan 1, 1983

By L. O. Bacon

This Bureau of Mines report summarizes the results of laboratory work in the design of instrumentation for obtaining the dynamic tensile strength of rock at minimum loading. Minimum loading is defined as the lowest tensile loading by pulse reflection to cause fracturing. The instrumentation for obtaining dynamic tensile strengths of rock cores evolved into the use of a compressed-air pellet gun to impact one end of a rock core, suspended by wires, at increasing increments of air pressure. Maximum strain was measured on most or all of the impacts, and the strain at fracture of the core was obtained by extrapolating the pellet velocity-strain curve to the pellet velocity at fracture. Stress at tensile fracture was obtained from the maximum s train, and the dynamic Young's modulus was calculated from the rod velocity by using simple rod theory.

Jan 1, 1962