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By Albert L. Toenges

The development of Alaska depends on the existence of an adequate fuel supply in the Territory. The need to investigate coal deposits was recognized as early as 1911, when the first investigations were conducted in Alaska by engineers of the Bureau of Mines. Conditions existing in the Bering River and Matanuska coal fields, as found by Dr. Robert A. Holmes, former Director of the Bureau of Mines, are described by the Honorable W. L. Fisher, former Secretary of the Interior./ Following Dr. Holmes' investigation, a party of Bureau of Mines engi¬neers headed by R. Y. Williams visited the Bering River field in 1912 in cooperation with the Navy Department. A detailed examination was made of the Bering River field, and 855 tons of coal were mined from three prospects on Trout Creek. This bulk sample was delivered to the Navy for steaming and other tests. A description of the work of the field party and results of tests of the coal by the Navy Department and the Bureau of Mines has been published.

Jan 1, 1949

By Edward F. Divers

Tills U.S. Bureau of Mines report briefly evaluates the advantages and disadvantages of basic dust control techniques presently used by U.S. coal preparation and mineral processing plants. These include ventilation, baghouse-type collectors, wet scrubbers, electrostatic precipitators, source control, sprays, good housekeeping, and personal protection devices. Two specific problems in these types of operations are also considered: dust collector system duct clogging, and control room dust control. Information provided in this report results from dust control research projects conducted by the Bureau at various coal preparation and mineral processing plants over the past decade to reduce workers' dust exposure. These studies indicate that plant ventilation systems normally provide the most cost effective method for dust control. Baghouses and scrubbers were also effective in specific applications, and examples of each are given. In extreme dust conditions, personal protection devices, such as respirators or the dust helmet, can also be highly cost effective.

Jan 1, 1990

By F. F. Aplan, J. A. Gutierrez-Rodriguez

"Contact-angle and flotation techniques were used to evaluate the influence of oxygen - both that inherent in the coal and that introduced by ambient temperature, aqueous oxidation - on a wide range of coal ranks. Oxidation was found to decrease the hydrophobicity and floatability of coal; with the effect being minor for coals of high rank but becoming increasingly important as the rank of coal is reduced. As an approximation, oxidation makes a coal behave as if it were one of lower rank. Frother only flotation' of coal· correlates with the captive-bubble contact angle whereas when oil is used as a collector, the flotation appears to follow the pattern shown by the water sessile drop on a fresh, un-reagentized coal surface. Coal recovery lost through oxidation may often be recovered by use of a variety of collectors, of which No. 2 foe! oil is among the best of those reagents tested. A simple alkali-extraction test may be used to estimate the influence of oxidation on coal preparation processes and use.INTRODUCTIONThe hydrophobicity of coal is not only a function of its rank but also of the extent of oxidation of the coal during and subsequent to its formation. Weathering and oxidation processes may proceed in-situ for coal deposits that outcrop near the earth's surface, or the oxidation of the coal particles may occur during mining, stockpiling or processing. Such oxidation, whether it affects the bulk-coal sample or on1y a thin outer layer on the coal surface, can dramatically influence the wettability of the particle and hence such processes as flotation, filtration, flocculation and dispersion.Many of the studies made on the oxidation of coals ·were designed to study its effect on flotation, coking or pyrolysis. The. present study 'is directed exclusively toward the effect of oxidation on the hydrophobicity and floatability of the coal. One of the first studies of the effect of oxidation on coal flotation was that of Sun [l] who found that as oxidation proceeds, coal becomes progressively more hydrophilic. Low-temperature oxidation (100-150°C for 250 h) generally lowered the coal floatability with an oily collector only slightly, but more extensive oxidation (200- 3500 C for 250 h) reduced coal floatability seriously. Sun also found that cationic amines were effective collectors for the oxidized coal which infers that oxidation makes the coal more negative in solution. He attributed the loss of floatability to be due to the accumulation of water-insoluble oxidation products at the coal surface. Gayle et al. [2] found that oxidation adversely affected coal flotation when an aliphatic-alcohol frother was used, though a small amount of oxidation appeared to improve the floatability of some coals using a kerosene-pine oil, collector-frother mixture in pilot-plant testing. Prolonged oxidation adversely affected the flotation recovery of the coals tested, the effect being more pronounced when an alcoholic-type frother only was used. They also noted that the reduction in floatability of lower rank bituminous coals was more affected by oxidation than was that of higher rank bituminous coals."

Jan 1, 1989

By Harry R. Nicholls

A simple economical method has been developed for determining the in situ longitudinal and shear velocities in rock from which its elastic constants can be calculated. By detonating small charges of high explosives in shallow drill holes near a free surface, both longitudinal and shear waves were generated simultaneously. Accelerometers and velocity gages mounted to the rock surface were used to record the arrival time for both waves over travel path lengths from 50 to 450 feet, Measurements were made in two rock types. From the arrival time measurements, the longitudinal and shear wave velocities were calculated. From these velocities and the density of the rock, the elastic constants were calculated. The dynamic elastic constants of drill core samples of the two rock types were determined in the laboratory by the resonant-frequency method, The lab- oratory and in situ elastic constants are compared and significant differences noted. In general, there is less spread in the in situ data than in the laboratory data, and Poisson's ratio does not fall outside the theoretical limits for the in situ data as is often the case for laboratory-determined elastic constants.

Jan 1, 1961

By By Staff

"These proceedings consist of papers presented at a Bureau of Mines Technology Transfer Seminar on postdisaster survival and rescue research. Several seminars are held each year to bring the latest results of Bureau research to the attention of the mining industry as quickly as possible.INTRODUCTIONThe postdisaster research program is directed toward research and development of technology and equipment that increases the chances of a miner surviving or being rescued after an underground mine disaster. A disaster is an accident of major proportions, and it may result in the entrapment of miners whose normal egress from the mine is cut off. This often necessitates a rescue operation and a means of keeping the trapped miners alive while they await rescue. The Bureau is currently pursuing research to develop the technology that will enhance the ability of miners to survive such an occurrence. The research is divided into two basic problem areas, survival and rescue. Both areas are concerned with the inability of miners and rescue teams to cope with the postaisaster environment, such as toxic gases, unstable roof conditions, water flooding, and lack of oxygen. In addition, research is also conducted to find ways of locating and quickly reaching trapped miners. Most of the research conducted by the Bureau has been directed toward the postdisaster problems associated with coal mines. However, most of the research results are also applicable to noncoal mines as well.The papers presented in these proceedings address some of the recent research conducted by the Bureau of Mines that has been directed toward the postdisaster problems outlined above. The topics covered range from an overview of the technology developed for oxygen selfrescuers to training programs for mine rescue. Any questions or comments pertaining to this research are encouraged and appreciated. Open file report (OFR) references in the proceedings listed as available from NTIS may be obtained from the National Technical Information Service, Springfield, Va. 22161, and are also available for reference at Bureau of Mines facilities in Denver, Colo., Twin Cities, Minn., l3ruceton and Pittsburgh, Pa., and Spokane, Wash.; the Department of Energy facility in Morgantown, W. Va.; the National Mine Health and Safety Academy, Beckley, W. Va., and the National Library of Natural Resources, U.S. Department of the Interior, Washington, D.C."

Jan 1, 1982

By J. S. Browning

The purpose of this Bureau of Mines project was to develop a method for recovering kyanite and sillimanite from the present zircon-mill tailing of the Jacksonville and Starke, Fla., plants of Humphreys Gold Corp. The kyanite and sillimanite in the ore are not being exploited at present, but procedures for recovering the two minerals were worked out by the Bureau in the interest of conserving natural resources. The current zircon-mill tailing of the Starke plant contains up to 20 percent of a mixture of kyanite and sillimanite. A similar product of the Jacksonville plant contains up to 15 percent kyanite and sillimanite. The average annual production of the tailing now being stockpiled contains several thousand tons of the two minerals. Laboratory batch-flotation tests were made on the materials to determine the feasibility of flotation methods for recovering high-grade concentrates. Various reagents were employed under different conditions to determine the optimum conditions for flotation of kyanite and sillimanite and retardation of the gangue materials. The results of the preliminary flotation tests were encouraging enough to warrant more comprehensive testing of a larger sample of the ore in the laboratory pilot plant.

Jan 1, 1956

By X. Shi, K. S. Kaspnak

"The generation of free radicals from reactions of nickel (Il)-thiol complexes with molecular oxygen and model lipid hydroperoxides was investigated by electron spin resonance (ESR) utilizing 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap. Incubation of nickel (II) [Ni(II)) with cysteine in an aerobic environment generated hydroxyl (·OH) radical, which then reacted with cysteine to generate a carbon-centered alkyl ( · R) radical. Radical generation was inhibited under a nitrogen atmosphere. Model lipid hydroperoxides, cumene hydroperoxide, and I-butyl hydroperoxide enhanced the yield of these radicals and also generated an alkoxyl (·OR) radical. Radical yield decreased by approximately half under a nitrogen atmosphere. Although histidine did not cause radical formation in the reaction between Ni(II) and cumene hydroperoxide under aerobic conditions, the addition of histidine to a mixture containing Ni(ll), cysteine, and cumene hydroperoxide under the same experimental conditions increased the yield of · R radical but lowered the yield of ·OR and ·OH radical adducts. It thus appears that histidine caused the ·OH attack to be more site-specific. Similar results were obtained utilizing 1-butyl hydroperoxide. Penicillamine or N-acetylcysteine yielded similar results except that under aerobic conditions, reaction between Ni(ll) and N-acetylcysteine without hydroperoxide did not generate a significant concentration of free radicals. Under the same experimental conditions, cystine did not generate any detectable free radicals, suggesting an important role of the -SH group in Ni(II)-mediated free radical generation. The results indicate that free radical generation from the reaction of Ni(Il)-thiol complexes and molecular oxygen, and/or lipid hydroperoxides, may play an important role in the mechanism(s) of Ni(II) toxicity and carcinogenesis. INTRODUCTIONWhile nickel is a well-recognized carcinogen [l, 2]. the underlying biochemical mechanisms remain unclear (3, 4). Recent studies suggest that these mechanisms may involve oxidative DNA damage through free radicals, especially the hydroxyl (•OH) radical [5-13]. The mechanisms of nickel carcinogenicity and toxicity may also involve lipid peroxidation [14-21]. Unlike ferrous ion [Fe(II)], the Ni(II) cation itself does not directly react with 02, H2O2, or lipid hydroperoxides to generate free radicals [12, 21]. However, it has been reported that Ni(II) complexes with certain synthetic oligopeptides, e.g., tetraglycine or glycylglycylhistidine, make Ni(II) reactive with 02. This reaction results in transitory formation of Ni(III) and degradation of the organic ligand via free radical reactions [22]. Such Ni(II)-peptide complexes are also capable of reacting with H2O2 to produce oxygen free radicals [11, 12]. Although the cellular environ¬ment may not contain these particular peptide ligands that are known to render Ni(II) redox active in vitro, it does contain a variety of oligopeptides that are capable of forming Ni(II) complexes at physiological pH, and thus may facilitate Ni(II) redox activity in vivo. These oligopeptides include glutathione (y-L glutamylycysteinylglycine), carnosine (homocarnosine (y aminobutyryl-L-histidine), and anserine ( B-alany1-3-methyl-L-histidine)."

Nov 1, 1995

By Michael J. Friedel

As part of an investigation aimed at mitigating the hazards caused by abandoned mine openings, the Bureau of Mines conducted a series of electromagnetic surveys in the Galena, KS, area of the Tri-State mining district. The application of monostatic ground-penetrating radar (OPR) and inductive electromagnetic methods for detecting and delineating hazardous mine openings and attendant features was demonstrated to be feasible for shallow mine workings (i.e., less than 35 ft) occurring below flat-lying areas. Accurate determinations of depth to a mine roof appeared to be limited to roughly 20 ft using the GPR method. Features such as mine voids, fractures, and zones of subsidence were located beneath the Mainstreet (State Highway 26) site using the GPR system. Both the GPR and inductive electromagnetic techniques satisfactorily located mine openings and pillars at the Hell's Half Acre site. Geophysical interpretations were supported by exploratory drilling and mine maps.

Jan 1, 1990

1. Alford, N.G. quantity, of timber used in soft-coal mines and how much will be needed for the future. Gives a table of estimated increase in mine timber consumption in the future. A.I.M.E. Separate. 1336-C 1924. 2 Clark, B.M. The forest and the mine. Rept. Conference of Wood-Using Industries, Harrisburg, Pennsylvania. Apr. 13-14, 1921, pp. 58-62. Describes experience of a Pennsylvania mining company in depletion of timber supply and conservation methods adopted.

Jan 1, 1925

By R. Blickensderfer

An impact wear testing machine was devised by the Bureau of Mines that simulates the repeated impact conditions encountered in large milling and grinding operations where breakage and spalling are problems. The apparatus provides data on materials that may help in the design of alloys with improved resistance to deformation, spalling, and breakage. The test blocks are 2 in thick by 6 in by 8 in. Impacts are produced by dropping 3-in-diam balls weighing 4 lb from a height of 10 ft. Tests were run until breakage occurred or to a total of 100,000 impacts. Four types of failures of the test block were observed: (1) cold flow of the bulk material by plastic deformation, (2) flaking of the surface in the impact region, (3) spalling of the block to form a crater in the region of impact, and (4) breakage of the test block into two or more major pieces. The effects of composition, heat treatment, microstructure, and hardness on types of failure are discussed.

Jan 1, 1983

By H. H. Schrenk

There are several well-recognized procedures for controlling exposure to hazardous atmospheres in industry. They include (a) substitution of less toxic material, (b) enclosure of processes, (c) wet methods, (d) local exhaust, (e) general ventilation, and (f) use of respiratory protective devices. In addition to their employment as a control measure in occupational exposures, respiratory protective devices also are essential in emergencies that may arise from failure or improper use of other control equipment. Respiratory protective devices usually are employed to supplement other methods of control, as temporary expedients, or when other methods are not readily applicable or practicable. It seems reasonable to assume, however, that where respirators are used consideration has been given to the factors involved and that the devices can provide satisfactory protection if used properly. Their use should not be arrived at simply by a process of elimination of other methods that are more difficult to apply.

Jan 1, 1943

By L. F. Willmott

The production operation of a Kerpely gas producer at Louisiana, Mo., is described. This unit, originally designed for airblown operation was modified to permit using oxygen in the blast in place of air. The first runs J for test purposes, were made in June 1950. After this, seven production runs were made and these are the subject of this report. Total gasification time was 245 days. In each run, Nut or Pea coke or mixtures of both at a rate varying from 1,700 to 2,300 pounds per hour was converted with oxygen and saturated steam to produce synthesis gas - primarily carbon monoxide and hydrogen -approximating a predetermined rate of 80,000 to 95,000 cu. ft. per hour and a predetermined hydrogen-carbon monoxide ratio, The requirements per 1,000 std. cu. ft. of (CO + H2) were 21.6 to 30 pounds of coke, 213 to 267 std. cu. ft. of oxygen, and 3L4 to 47.B pounds of steam.

Jan 1, 1955

By Marting J. Gavin

The twentieth century has often been spoken of as the age of petroleum, and from many viewpoints it can be justly considered so. Certainly the petroleum industry is one of enormous importance to this country, industrially, financially, and economically. The United States, however, at present producing over 60 per cent of the world's total output of petroleum, is not producing petroleum at a sufficient rate to provide for its own domestic, consumption. For several years this country has been importing increasing quantities of crude and partly refined oils from Mexico, and has been drawing heavily on domestic stocks of petroleum. Production in the United States is increasing, but it is not increasing at the same average rate as domestic consumption, nor is it probable that in the future domestic production will increase sufficiently to satisfy the demands of domestic consumption, but on the contrary, in the opinion of those best qualified to know, the peak in the curve of domestic production of crude petroleum will be reached in a comparatively few years, whereas the consumption of petroleum and its product will increase at a continually growing rate. This country, then, must turn, and as the increasing imports from Mexico indicate, is turning to other sources than the crude petroleum, produced in this country to make up the deficit between domestic production and domestic consumption of petroleum and its products,

Jun 1, 1920

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of Colombia has been prepared from the best available information in Washington, but is released subject to correction and amplification; if necessary, by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State. SYNOPSIS OF LAW Minerals in Colombia belong to the owner of the soil unless otherwise provided in the law. The following lands and deposits, however, are described as fiscal property of the State: Class 1. The public lands, mines, and salines which belong to the individual States (now Departments) prier to the adoption of the present constitution (1886).

Jan 1, 1929

By Mark I. Copeland

Bureau of Mines researchers investigated the combined effect of copper and tin additions on the mechanical properties of hot-rolled steels. Wrought steels containing 0.2 wt-pct C and up to 0.2 and 1.0 wt-pct Sn and Cu, respectively, were made and evaluated by conducting tensile and impact tests and electron-beam microprobe and electron microscopy examination. Tin additions did not significantly affect the tensile properties of steel at different copper contents in the hot-rolled condition. Tin lowered the copper content at which strengthening by copper precipitation normally starts, 0.8 wt-pct, and decreased the strength of steel aged at 1,022° F (550° C). The most adverse effect of tin was lowering the notch toughness of steels at most copper contents.

Jan 1, 1976

By Leslie H. Sharp, Martin J. Gavin

Those of the oil-shale operators in this country who are sincerely attempting to make a real industry out of oil-shale developments, are anxious to obtain fundamental data on the retorting of oil-shale; particularly as regards the effect of certain variable factors in the process of retorting on the quantity and quality of products yielded from oil shales when they are subjected to destructive distillation. From careful examination of a con siderable number of suggested processes for treating oil shales and the con flicting ideas on which they are designed, it seems probable that accurate information of a fundamental nature is highly essential to the successful establishment of an oil-shale industry in this country. . Accordingly, the United States Bureau of Mines, in cooperation with the State of Colorado, is undertaking to furnish some definite and impartial information of this type through investigations now under way at the University of Colorado, Boulder, Colo. A retort for the distillation of oil from oil shale has been designed and installed, together with the necessary auxiliary equipment for controlling and determining variable factors of distillation, and for recovering and de termining the quantity and quality of the products yielded from the shales. The retort is of such a nature that conditions of retorting can be accurately . and completely controlled, and varied at will. It is not designed as a com mercial retort, but only for research purposes. A testing laboratory with equipment necessary for the examination of the shales, physically and chemic ally, and the products yielded by them, has also been fitted up . The material used in the investigations is oil shale obtained from the DeBeque, Colorado, shale field. It yields on distillation in the Bureau of Mines testing apparatus, about 42 gallons of oil to the ton, and is there fore a fairly representative sample of the shales that probably will be first worked in Colorado. The shale used will be as uniform as possible in character and oil yield and will all be obtained from the same seam at the same point, in order to avoid the introduction of unnecessary variable factors in the tests and to render results strictly comparable •

Jul 1, 1920

By John D. Bardill

This report covers magnetic surveys in the Dannemora arca , which was part of a general survey of magnetite deposits in New York started in 1943 . The objective of these surveys was to afford a basis for the selection of exploration projects .

Jan 1, 1947

By Arthur L. Murray

"During recent months much criticism as to the efficiency of mine labor has been heard from various, sections of the country. No doubt much of this criticism has been well founded. The present lack of efficiency and of stability is due primarily to a spirit of restlessness and partial irresponsibility engendered during the transition from war conditions to peace time conditions. This spirit or unrest not only among the laboring classes but in every branch of the human family following a period of intense nervous tension in a nation appears to be a natural sequence of war and beyond the control of man. This condition will gradually disappear, and the majority of our people will again assume their natural order of living, but labor will for a considerable period be sensitive to these influences, whether they be exerted for good or for evil. Employers of labor should take cognizance of this fact and bend every effort towards the development of measures that promote efficiency and permanence of the working force.Labor efficiency depends upon many and varied factors. Some of these factors as applied to mine labor are briefly enumerated in the following paragraph:Selection and Placement of Manpower:In the selection of men the two main considerations are physical ability and adaptability. The laws of mechanics should be applied in the selection of men as in the selection of machinery. If a machine is required for a certain class of work, the type of machine known to be mechanically fit for such work is selected. Likewise, men should be selected with regard to their physical and temperamental fitness for the kind of work expected of them."

Apr 1, 1920

By Albert L. Toenges, Theodore R. Jolley

"The development of Alaska depends on the existence of an adequate fuel supply in the Territory. The need to investigate coal deposits was recognized as early as 1911, when the first investigations were conducted in Alaska by engineers of the Bureau of Mines.Conditions existing in the Bering River and Matanuska coal fields, as found by Dr. Robert A. Holmes, former Director of the Bureau of Mines, are described by the Honorable W. L. Fisher, former Secretary of the Interior.4/Following Dr. Holmes' investigation, a party of Bureau of Mines engineers headed by R. Y. Williams visited the Bering River field in 1912 in cooperation with the Navy Department. A detailed examination was made of the Bering River field, and 855 tons of coal were mined from three prospects on Trout Creek. This bulk sample was delivered to the Navy for steaming and other tests. A description of the work of the field party and results of tests of the coal by the Navy Department and the Bureau of Mines has been published.During 1920 to 1922, the comparative steaming properties of Alaska bituminous coal, lignite, and wood were determined by the Bureau of Mines.6/In the early 1920's, the Bureau of Mines established a coal laboratory at Anchorage, where Alaska coals were analyzed. Subsequently, this laboratory was transferred to the Alaska Railroad and was used by the railroad for coal and other tests.Since 1910, the Bureau of Mines has made analyses of coal from Alaska, and the results of these analyses have been published.7/ The coal analyzed was obtained from mines, tipples, delivered lots, and face samples of coal deposits, and these samples were obtained in the field by engineers of the Bureau of Mines and geologists of the U. S. Geological Survey.Because of the shortage of petroleum and petroleum products in Alaska during the war, low-temperature carbonization assays of coals from the Broad Pass, Forty-Mile, Matanuska, and Nenana fields were made by the Bureau of Mines, and the results were published.Coal beds in the Matanuska field contain interbedded impurities in the form of shale, clay, and bone. The coal should be cleaned mechanically to obtain a satisfactory fuel. A coal-preparation study of bituminous coal from the Eska and Evan Jones mines was made by engineers of the Bureau of Mines, and the results were published.9/Coal production in Alaska is less than the requirements, and coal is imported to make up the deficiency. The cost of this imported coal is high. Greater production is necessary to supply coal for Army installations, industry, and homes. At present, there is only one bituminous coal mine (Evan Jones) in Alaska. The output of this mine is used at Fort Richardson, Anchorage, and by the Alaska Railroad. The economic life of this mine is limited (reported to be 3 years), and its closing, because of accidents or exhaustion, will cause great hardship to the inhabitants of Alaska. There is need to develop new, modern mines for the production of bituminous coal in the Matanuska field."

May 1, 1949

By Fred N. Kissell

Air recirculation caused by dust scrubbers at coal mine working faces was examined by the Federal Bureau of Mines with regard to the potential hazards caused by a possible buildup of methane gas. A theoretical analysis indicated that there was no apriori way to predict the effect of scrubber recirculation on methane concentration levels. Experiments conducted in a full-scale model of a working face area indicated that methane levels were dependent to a great extent on the location of the scrubber exhaust, but that the scrubber recirculation did not substantially increase the methane concentration above those levels that would have prevailed were the scrubber not in operation. An analysis of two underground scrubber trials showed that the scrubbers had no significant effect on methane levels, and a review of explosions attributed to recirculation showed that these were characterized by a lack of fresh air as well as recirculation. It was concluded that high methane levels are due more to a lack of fresh air than to recirculation.

Jan 1, 1975