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By Dale E. Wittmer

Nonoxide ceramic materials could substitute for high-temperature alloy steels containing imported critical and strategic materials such as cobalt, chromium, and nickel if their high-temperature properties can be improved. An important result of this substitution would be a reduction of the Nation&apos;s need for imports of critical and strategic materials. In this Bureau of Mines investigation, the primary objective was to produce high-purity u1trafine (particles <5 ~m equivalent spherical diameter (ESD)) alpha-silicon carbide (a-SiC) powders with improved high-temperature properties using the Bureau&apos;s patented turbo-milling process. A secondary objective was to determine the feasibility of using polymer mill construction materials as a means of eliminating metal contamination from the turbomill. U1trafine a-SiC powders with BET (Brunauer-Emmett-Te11er) surface areas from 30 to 35 m2/g (~0.06 ~m particle ESD) were produced in an all-polymer turbomi11. These high-purity powders (with I-pct Band I-pct C additions) hot-pressed to greater than 99 pct of their optimal density and exhibited properties commensurate with those of commercially available a-SiC. The most promising of the construction materials tested for the major wear surfaces of the turbomi11 was u1trahigh-mo1ecu1ar-weight (UHMW) polyethylene, a polymer thermoplastic.

Jan 1, 1984

By Geoffrey G. Huggins

Discussions are presented of the three phases of the noise reduction program on flight-type coal conveyors. The three phases are identification of noise sources, evaluation of potential noise reduction concepts, and implementation of noise reduction which is intended to reduce conveyor noise to less than 90 dB(A) in the underground mining environment. The major noise sources are impacts of the chain on the tail roller and on the top and bottom decks. A total noise reduction of 11 dB(A) was achieved by using techniques which are applicable to retrofit. These are a vibration isolated tail roller and an isolated wear strip on the return deck. A theoretical model of isolation provided by the isolated tail roller is developed. Appendices are presented which contain information on other potential concepts and additional data generated.

Jan 1, 1976

By Jonathan S. Kelly

Effective control of respirable dust is one of the most serious problems associated with longwall mining in the United States. This report describes the development and the underground evaluation of ventilated cutting drums, on a double ended ranging drum shearer. The ventilated drum uses high pressure (1,500 psi) water sprays to draw air (3,500 cfm) through 12 airmoving tubes mounted in the drum hub. The sprays draw dusty air from the face side of the drum, scrub the air, and discharge the clean air on the gob side of the drum against a deflector plate. During a three week underground evaluation, the cutting drums reduced shearer generated dust levels at the shearer operators position by 40%, at the shield operators downwind of the shearer by 55%, and at the tailgate by 55%. Cutting and loading performance of the drums were superior to the mine?s conventional drums. After the evaluation, the mine continued to use the ventilated drums to finish mining the panel. During this 3 month period, there were no mechanical or seal failures demonstrating excellent system reliability.

Jan 1, 1987

By H. R. Beard

The Bureau of Mines investigated the absorption of radium and thorium from waste uranium leach liquor by clays and other materials. This work was conducted in support of the Bureau&apos;s goal of minimizing the environmental conflicts, impacts, and occupational hazards associated with mining and milling operations. Tailing and soil samples from New Mexico were evaluated for their potential to absorb radium and thorium from tailing liquors. Absorption ranged from 0 to 97 pct for radium and 0 to 60 pct for thorium. Some samples that readily absorbed radium were contacted with various salt solutions that could be present in tailing solutions to determine whether desorption would be a potential problem. The desorption of radium ranged from 0 to 75 pct. An alpha spectrometric method was used to determine the radium and thorium concentrations in the solutions and solids.

Jan 1, 1980

By H. S. Auvil, J. T. McCartney, J. D. Davis

"INTRODUCTION It is now generally recognized that the small-scale laboratory dilatometer method of test does not give results of much utility in predicting the expansion (or contraction) of a coal in a coke oven. The carbonizing conditions in the laboratory test differ radically from those in the oven; in this test, the charge is heated through the coking range of temperature as a whole, whereas in the oven, coking proceeds by layers parallel to the oven walls as each succeeding portion of the charge goes through the plastic range of temperature and coke formation sets in. The paths of the gases and vapors and the pressures set up are different in the two methods. Furthermore, the rate of heating in the test usually is much more rapid than in the oven. H. Koppers 5/ was perhaps the first to adopt apparatus and procedure whereby the layer coking of the coke oven could be simulated closely however, the heating progressed from one side of the charge only; later he experimented with a small coke oven with a movable wall heated from both sides. It is not clear how well the results in the later oven correlated with those of the earlier small test oven, but in a comparatively recent Koppers publication a modification of the original small test oven heated from one side is recommended 6/ Altieri 7/ was perhaps the first to experiment with the Koppers type small test oven in the United States and Brown- has tested a large variety of coals in a rectangular test oven of his own design heated from the sole or floor. Subcommittee XV of American Society for Testing Materials Committee D-5 is now making a study of the various methods proposed for determination of expanding and plastic properties of coal with a view to standardization. 9/"

May 1, 1939

By R. S. Fowkes

Jetstream pressure distributions and coal cutting rates were determined for a number of nozzles and under different operating conditions. The jetstrearn pressure distribution data were fitted to an assumed curvilinear equation by the utilization of a numerical least-squares technique with the aid of a digital computer. Subsequent manipulation of the approximation equation showed that the total force of the jetstream, rather than its maximum pressure or total kinetic energy per unit Lime, was the most significant quantity affecting the coal cutting rate. A shorter method for assessing the ability of a nozzle to cut coal was found.

Jan 1, 1968

By R. R. Sayers

Carbon monoxide poisoning is one of the most widely distributed and most frequent causes of industrial accidents . Carbon monoxide gas is a product of incomplete combustion , and since it is without color , odor , or taste , its presence is frequently unsuspected in many places where it exists . It is an ever present danger about blast and coke furnaces , smelters , and foundries . It may be found in buildings having a leaky furnace or chimney , and in buildings where a gas stove is used without a proper flue connection , such as is often found in tenements , tailor shops , and boarding houses . Hospitals receive annually a great number of victims of poisoning , either by accident or in an attempt at suicide , from artificial illuminating gas . People may be affected by leaks wherever water gas is formed or used . The exhaust gases from gasoline motors under average running conditions usually contain 5 to 7 per cent carbon monoxide , and sometimes as much as 13 per cent ; deaths from running an automobile engine in a closed garage are not infrequent . A similar danger may arise in operating gasoline engines in launches without sufficient ventilation . The gas is formed also in stoker rooms , in gun turrets on battleships , in petroleum refineries , and by the Lablanc soda process in cement and brick plants . In underground mines carbon monoxide may appear as the result of shot firing , mine explosions , or mine fires , and in tunnels where automobiles , coal or oil - burning locomotives are operated . In spite of the common occurrence of carbon monoxide poisoning there appears to be no uniformly recognized treatment for a person overcome by carbon monoxide . In the rescue work of the United States Bureau of Mines , however , a method has been developed which has been supported by laboratory investigation , and has proved successful in practical experience , over a period of years . As outlined in this article , the method is useful in the hands of first -aid men as well as physicians .

Dec 1, 1921

By L. R. Burdick, J. F. Barkley

"The agglomerating index of coal is an index based upon the nature of the coke residue left when the standard volatile-matter determination of the well-known proximate analysis is made. In this determination a small amount of coal is heated in a container to about 950° C. (1,742° F.), at which temperature the volatile matter is driven off, leaving a coke formation. The coke residues for various coals are quite different in physical structure: and, for some time past, work has been done on studies of the nature of these residues in connection with the coking of coal. In 1934 Gilmore, Connell, and Nicolls proposed use of the agglomerating index for indicating the dividing line between noncaking coals and those having weakly caking properties. 4/ Its use was adopted in the standard classification of coals by rank as a requisite physical property index to differentiate semianthracite from low-volatile bituminous coal and also high-volatile ""C"" bituminous from subbituminous ""A"" coal, as shown in table 1, the standard coal classification adopted by the American Society for Testing Materials and the American Standards Association. 5./In studying the agglomerating properties of coals based on the coke residue the Bureau of Mines has adopted the notation given in table 2. Coals that in the volatile-matter determination give a coke residue either in the form of an agglomerate button that will support a 500-gram weight without pulverizing or a button that shows swelling or cell structure are considered to be agglomerating."

Nov 1, 1938

By N. S. Dalal, V. Castranova, X. Shi, W. Wrr, V. Vallyathan

"SUMMARY Data presented here indicate that freshly fractured silica exhibits surface characteristics and biologic reactivity distinct from aged silica, and on this basis we propose that these surface features may lead to enhanced manifestations of lung Injury. Grinding of silica produces ~10"" Si and SI-O (silicon-based) radicals per gram of dust on the particulate surface which are characterized by an electron spin resonance (ESR) spectrum centered around g = 2.0015. These silicon-based radicals react with aqueous media to produce OH radicals, which are demonstrable using a DMPO spin trap. The concentration of silicon-based radicals in silica decreases with aging in air and exhibits a half-life of ~30 h, whereas its ability to generate OH radicals in aqueous solution decreases with a half-life of ~20 h. However, on storage in aqueous media, the concentration of silicon-based radicals end the dust's ability to generate OH radicals decrease significantly within a few minutes. Freshly ground silica is also more biologically reactive than aged silica, because freshly crushed silica activates a greater respiratory burst In alveolar macrophages than aged silica, i.e., storage of ground dust in air decreases silica-Induced superoxide anion secretion, hydrogen peroxide release, and NBT reduction by 25%, 68%, and 43%, respectively. Furthermore, compared to aged silica, freshly ground silica exhibits a greater cytotoxic effect on cellular membrane Integrity, i.e., a 1.5-fold increase in LDH release from macrophages, a 36-fold increase in hemolytic activity, and a three-fold increase in the ability to induce lipid peroxidation. Because acute silicosis is frequently associated with occupations in which freshly fractured crystalline silica of respirable size is generated, the present study suggests that fracture-generated silicon-based radicals may play a significant role in the pathogenesis of this disease. AM REV RESPIR DIS 1955; 133:1213-1218IntroductionOccupational exposure to crystalline silica can be associated with either chronic or acute pulmonary disease. Chronic silicosis becomes manifest 20 to 40 years after first exposure and is characterized by development of concentric hyalinized nodular lesions in the lung with the de-velopment of dyspnea over a period of several decades. Acute silicosis, on the other hand, is manifested by a rapid on-set after exposure and is characterized by the accumulation of an amorphous granular lipoprotein exudate in the airspaces and rapid development of respiratory disability within a few years (1-3).Information is growing concerning the etiology of chronic silicosis. Studies sug-gest that several mechanisms may be in-volved in the development of fibrosis. Lung injury may result from silica-induced release of lysosomal enzymes from alveolar macrophages (4, 5). In ad-dition, silica-induced activation of su-peroxide anion and hydrogen peroxide release from alveolar macrophages may result in oxidant-induced damage to lung parenchyma (6). Silica exposure can also result in the release of mediators from alveolar macrophages which enhance the proliferation of fibroblasts and the syn-thesis of collagen by these pneumocytes (7, 8)."

Jan 1, 1988

By J. E. Fraley

This report describes the preliminary results of a Bureau program to develop and test an inexpensive grout for full-column support of roof bolts. Various inorganic grouts were tested in both cartridge and slurry form. Tests were also performed on methods of water packaging and on the effect of fillers on the grout strength. Results showed that some grouts had poor early strength and exceptional mid-to long-term strength. Laboratory tests have shown that rapid-setting inorganic grout could be an economical replacement for resin bolts if the short-term strength could be increased. Further development to improve its early strength would need to be tested in the laboratory and underground to prove its potential for the mining industry.

Jan 1, 1987

By Neal M. Miur

"INTRODUCTION The Mineral Ridge-Clay Lick fault system in Crittenden and Livingston Counties, Kentucky, is one of the larger and more important fault systems of the Western Kentucky Fluorspar district. Total production from it up to July 1945 (chiefly since 1900) was approximately 80,000 tons of fluorspar ore, 10,000 tons of which came from the Mineral Ridge Fluorspar Co. tract 1, which was being operated by the Mahoning Mining Co. of Rosiclare, Ill. The fluorspar ore carries lead and zinc that can be recovered by milling, and the Mahoning Co. planned to log-wash the ore at the mine and then mill it in its mill at Rosiclare, The Mineral Ridge Fluorspar Co. properties were examined by O. M. Bishop, an engineer of the, Bureau of Mines, in August 1942. During 1943 and 1314, developments on the properties were under observation by X. B. Starnes, of the Bureau, and it was decided to diamond-drill tracts 1 and 2, as indications seemed favorable for opening up additional fluorspar ore bodies. Drilling was begun March 12, 1945, and was completed July 2, 1945, during which time 12 holed were drilled on tract 1 of the Mahoning Co.'s leases for a total of 3,637.1 feet, and one hole 359 feet deep was drilled on tract 2 of the Jennings lease. The Mineral Ridge-Clay Lick fault system, 4 to 47 feet wide, was encountered in all holes at 126 to 265 feet."

Apr 1, 1947

By R. V. Ramani

"Exposure to respirable contaminants in mine atmospheres has long posed a serious hazard to miners. The control of these hazards, some of which can have sudden and catastrophic effects and some others, slow and long enduring consequences, has been a major concern for labor, management and government alike. This concern has manifested itself in four primary mechanisms of control -- (1) regulatory control through minimum standard setting by the passage of mine health and safety laws, (2) engineering control through design and operation of 'mines according to the best recommended practices, (3) medical control through periodic physical examinations, wearing personal protection devices, etc., and (4) legal and social control through workmen's compensation laws for occupation related health deterioration:-The respirable contaminants in mine atmo¬spheres are toxic and explosive gases, toxic and explosive dusts, diesel exhaust particu¬lates, radon progeny, etc. Perhaps the most important of all these and the most widely occurring in mine atmospheres is respirable dust, an inevitable product of fragmentation, a unit operation fundamental to all mining operations. In fact; the-most serious health hazard for workers in the mining and minerals processing industries is still the exposure to respirable dust, and solutions to the problem of respirable dust disease remain to be found.The 1969 Coal Mine Health and Safety Act and its provisions for the respirable dust standards in underground coal mines are briefly reviewed. An overview of the research accomplishments in meeting the standards is presented. The current state of knowledge on the effectiveness of the standards and the new and emerging problems are discussed. A brief summary of the research programs of the Generic Technology Center on Respirable Dust is presented.In general, underground mines are becoming increasingly safe. The mine atmospheric environment is definitely improving * Professor and Head, Department of Mineral Engineering,-The Pennsylvania State University, University Park, PA for the better. Significant progress has been made in lowering the dust levels in mines. It is generally agreed that mines are less dusty today than they were a decade ago. However, as long as the risks of occupation-related diseases are not completely eliminated, vigilance can hardly be relaxed, and the search for engineering solutions must be intensified."

Jan 1, 1988

By H. D. Baylor

This paper, describing the operations of the Louisville Cement Co. in quarrying limestone for the manufacture of quicklime, is one of a series being prepared for and published by the United States Bureau of Mines on stone quarries throughout the United States. Those papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating 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. ACKNOWLEDGMENTS The author acknowledges the assistance of J. H. Lemmon, plant superintendent, Charles Taylor, plant engineer, and F. H. Compton, chief engineer, of the Louisville Cement Co. in the compilation and preparation of this paper.

Jan 1, 1932

By R. E. Heithecker

[The separation of enormous quantities of water produced with the oil in some West Texas fields necessitated. the use of special equipment other than the regular lease tanks. Several methods Were used with varying degrees of success. They include, the water-trap, hay tank and gun barrel, gun barrel and settling tank, chemical, and electrical-dehydration methods. The water trap which has been used extensively in the Hendricks field, and in some instances has been installed in the Yates field separates the water&apos; and. oil under high pressure before tile liquid and gas pass through the flow ?bean. The first trap was constructed and installed by the Southern Crude Oil Purchasing Co. in July, 1928. By July, 1929, approximately 300 traps were in use.]

Jan 1, 1932

By R. R. Sayers

Although the attention of those interested in diseases peculiar to mining as teen focused recently on one duct disease - silicosis - other respiratory diseases may cause more suffering and economic loss. The increased incidence of these diseases usually is attributed to exposure to abnormal air conditions underground, such as sudden changes from high to low temperatures, excessive dust, and noxious gases. The principal respiratory diseases to which the mine is subject axe bronchitis, influenza and pneumonia, pulmonary tuberculosis, anthracosilicosis, and. silicosis. Although the mortality statistics in some of the tables included in this paper are old they have been corroborated by later, lees complete data Bronchitis Bronchitis is en inflammation of the bronchial tubes due, among other causes, to the inhalation of irritants such as dusts (organic and inorganic). Occupations that entail exposure to atmospheres polluted, by irritating gases carry with them the risk of bronchitis. According to Collie (1), it cannot be distinguished clinically from bronchitis occurring among the general population, and its association with tae inhalation of dust or gases usually is unrecognized.

Jan 1, 1941

By John P. Hager

This study investigated the formation of vapor complexes between aluminum chloride and the chlorides of iron, titanium, and silicon. For the A1-Fe-C1 system the proposed gaseous complex species is Al2Fe2C112(g), which is formed according to the reaction 2A1C13(s) + 2FeCl3(s) = Al2Fe2C112(g) The corresponding free energy expression was determined to be ?G° = 38091.49 - 71.45 ? T 400 < T < 600°K The vapor composition above AlC13 melts contaminated with FeC13 was calculated. In the Al-Ti-CI and Al-Si-Cl systems the proposed vapor complex species are Al2Ti2Cl14(g) and Al2Si2Cl14(g) respectively. Free energy expressions were estimated for the formation of the two complex species. Again, the vapor composition above AlCl3 melts contaiminated with TiCl4 or SiCl4 was determined. The results of this study were compared with previous studies on the three systems.

Jan 1, 1980

By E. P. Ferrero

Analyses of 38 crude oil samples from 25 fields in Algeria, Libya, and Nigeria are presented in this report. The 38 crude oils are listed alphabetically by country and field. Also shown are the geographic and geologic sources of the samples analyzed, the companies that supplied the samples, the general characteristics and analytical and computed data, and the production for the fields from which the samples were obtained.

Jan 1, 1966

By L. C. IlsLey

Cooperation between the United States Bureau of Mines and the Safety in Mines Research Board of Great Britain, continuous, since 1924, s made possible this and other papers on safety subjects. Grateful acknowledgment is made to representatives of the board for their assistance in arranging visits to several mine-safety stations, and to F. R. Wynne, Deputy Chief Inspector of Mines, for arranging visits to mines in Great Britain and certain other countries in Europe. During the summer of 1927 the writer had the privilege of visiting the mine-safety testing stations An Great Britain, Belgium, Germany, and France, in the order named. All of these countries have large coal mines, many of which are rated as gassy. Therefore, a the installation of electrical equipment is contemplated each of these countries is confronted with the same safety problem as is the United States that is, the development of electrical equipment that will not, ignite gassy atmospheres should they through neglect or accident surround the equipment. The means employed by these countries in safeguarding gassy mines should therefore be of general interest to safety engineers of American coal mines, and a brief survey is given for each of the four countries mentioned. The fourth or last of these surveys covers conditions in France.

Jan 1, 1929

By C. W. Davis

This is the first of a series of papers being; prepared as the work progresses in a study of the hydrometallurgy of manganese. The investigation is being made in an endeavor to make possible the utilization of lour-grade domestic manganese ores. The value of a hydrometallurgical process for manganese depends on the present and future uses for manganese products.

Jan 1, 1930

By Richard C. Barth

Fourteen field plots were established at active coal mines in the Northern Great Plains. A wedge was cut into spoil and backfilled with soil; soil depth ranged from 0 to 152 cm over a linear distance of 15 m. Perennial grasses were planted in each plot, and production was measured from 1978 to 1981. Based on spoil traits and biomass response patterns, plots were grouped into four types. Spoil for Type I plots was near neutral, slightly saline, nonsodic, and clay loam in texture. Perennial grasses reached maximum production with approximately 50 cm of soil depth. Spoil for Type II plots was characterized as sodic and fine textured; soil-depth requirements averaged 83 cm for maximum production. Spoil for Type III plots was characterized as strongly acid, and production increased throughout the soil depth range tested. Spoil for Type IV plots was similar to soil in chemical and physical traits; there was no production response to soil depth. Soil depth requirements were also dependent upon precipitation and species. In general, soil-depth requirements decreased in dry years and with use of introduced species. An appendix contains data evaluations on an individual plot basis.

Jan 1, 1982