Search Documents

By Arno C. Fieldner

From July 1, 1949, to July 1, 1950, the Bureau of Mines conducted the research and technologic work on coal and coal products that is summarized in this report. The research, described in this fifteenth of a series of resumes, is presented in more detail in publications (see footnote references) that appeared during the fiscal year, though in some cases research data are given that have not been published elsewhere. Results of research in the experimental coal mine, on explosives, and on gas and dust explosions will be found in Bureau of Mines Report of Investigations 4228, Annual Report of Research and Technologic Work on Explosives, Explosions, and Flames, Fiscal Year 1950. An over-all view of our coal, oil, end natural-gas reserves was presented, and the future possibilities for the, production of synthetic liquid fuels from coal were delineated.3/

Jan 1, 1951

By Donald P. Schlick

Respirable dust provisions of the Federal Coal Mine Health and Safety Act of 1969 are designed to protect the most important resource of the coal mining industry--its workers. The Act imposes two respirable dust standards of 3.0 milligrams per cubic meter of air after June 30, 1970; and 2.0 milligrams per cubic meter of air after December 30, 1972. Under Federal regulations, each operator is required to carry out a dust sampling program established by the Secretary of the Interior and the Secretary of Health, Education, and Welfare, This program features the sampling of "high risk" face workers to establish that the exposure of each miner is below the dust standard, Mining sect ions, continuously in compliance with the regulations, may sample at less frequent intervals. In addition to requiring the mining company to take respirable dust samples, the Bureau of Mines will perform in-depth dust inspections twice a year, as well as frequent "spot inspections." The Bureau has established a semiautomatic computerized operation capable of processing over 1 million samples per year. This facility will be linked to various Bureau offices by a telecommunications system to provide automatic data printouts within hours after samples have been weighed.

Jan 1, 1970

By D. Harrington

Coal mines and mining-, as well as metal and nonmetallic mines and min¬ing, are not inherently unsafe, although mining people think they are and would like to have everyone else think so. It is now being demonstrated that mines can be operated with essentially as much safety as any other major industrial enterprise; but most mining people, including workers as well as officials, have been slow to realize or admit this. In the past, and with most people even at present, the idea has prevailed that it is utterly impossible to operate a mine without accidents. Although, as in all other kinds of industrial activity, it is true that some injury is likely on occasion to occur to some workers and an extraordinary accident may occur to one or more persons under exceptional conditions, mines can be operated with few if any accidents if a reasonable amount of the right kind of precautionary effort is exerted and kept in effect.

Jan 1, 1934

By T. T. Read, F. C. Houghten

"The bad effects upon the health and output of miners that result when the ventilating current in a mine lacks sufficient cooling power have been described by Harrington and Sayers in a previous report (1)*** The normal temperature of the human body is about 98.5°F. and whenever work is done by the muscles, indeed even when sitting still, the normal bodily processes generate heat which must be given off, otherwise the body will become overheated and a number of bad effects will be produced. If it were possible to so enclose a man that he could continue to breathe and no heat could escape from his body he would die within a short time. In a series of experiments made at the Pittsburgh Station of the Bureau of McConnell and Houghton (2) found that a dry-bulb and a wet-bulb temperature of 112.5°F could he borne for only 35 minutes, even when the subject was at rest. A wet-bulb temperature of 100.4°F (dry-bulb 157°F) could only be tolerated for 45°F minute. Under such conditions the bodily temperature rises as much as 45°F above normal and the pulse is accelerated. Very uncomfortable sensations are felt when the pulse rate exceeds 135. The human body, like any other internal combustion engine, must be cooled in order to function properly.Under ordinary circumstances the air surroundings people is enough coder than themselves to permit this heat generated within the boiy to be river off with¬out difficulty. At higher temperatures, or when the rate of work, with its corresponding generation of heat is high, the body can not throw off heat fast enough, so it begins to sweat and the evaporation of the sweat cools the body. But the results of the experiments cited above indicate that in still air, even with the body at rent, it can not adjust its temperature when the air is above 90° wet- bulb. J. S. Haldane (4) says ""at a wet-bulb temperature of 60°F the actual amount of work done by the miner begins to fall off; as the wet bulb temperature rinse farther the work Bona gradually diminishes to the vanishing point. Then the temperatures indicated by the wet-bulb exceeds 85°F hard work in a mine seems hardly or the commercial working of a mine the wet-bulb thermometer should not in generaI, be allowed to rise above 80°F, unless perhaps where there it a good current."

Dec 1, 1923

By Frederick C. Trutt

Research performed on arcing faults and their interaction; with electrical insulating materials within coal.-mine power-system enclosures is described. This work was performed at The Pennsylvania State University from 1 December, 1976 through 30. November, 1977. Results presented are interim in nature and future research is planned to integrate the simulations which have been constructed, as well as to apply developed experimental procedures to the evaluation of electrical insulating materials for use in coal-mine enclosures. The thrust of this research has been divided into several primary areas. These include the development of a theoretical procedure for computation of three-phase and line-to-line arcing fault currents as a function of time, formulation of an arc model based upon thermal-arc plasma properties so that arc voltages and energies may be computed, development of a simulation for pressure and temperature rises when an arc interacts with an electrical insulating material within an enclosure, experimental evaluation of electrical insulating materials in terms of their tendency to support an arc as well as their potential contribution to enclosure pressure rises, and integration of the above research areas to form overall procedures for theoretical and experimental evaluation.

Jan 1, 1977

By D. S. Kingery

Owing to changes in State mining laws, the Maryland Bureau of Mines requires all mine foremen to have a thorough, practical knowledge of mine gases and the limitations and use of recognized gas-detecting devices. This requirement involves immediate training of second-grade mine foremen and aspirants to qualify them for certification under the new law. Cooperation of the Federal Bureau of Mines was requested, and a plan for training was discussed and adopted. The methods used in Maryland aroused unusual interest by participating individuals, and the final results were very satisfactory. Consequently, it is thought that this plan will be of interest and assistance to other organizations faced with the need for such training.

Jan 1, 1952

By John H. Weitz

Dolomite, heretofore regarded merely as a variety of commonplace limestone, has suddenly attained headline prominence, partly because of the increase in demand for dolomite refractories to line metallurgical furnaces now working at an unprecedented rate of activity, but chiefly because it has become an ore of the light-weight metal, magnesium, needed in vast quantities for the manufacture of war machines. A multitude of inquiries, chiefly from war agencies and prespective operators, for data not only on locations of dolomite deposits but on their size and quality, has made it necessary for the Bureau of Mines to assemble all information available on this important subject. From the Bureau's own records, published information, and correspondence, date on locutions, extent, thickness, accessibility, workability, and chemical composition of high-grade dolomite deposits throughout the United states were accumulated for presentation herein. The report includes about 1,000 tabulations of analyses and a map showing locations of the deposits. The uses of dolomite are discussed in Bureau of Mines Information Circular 7192, "Occurrences and Uses of Dolomite in the United-States," published in 1941. The cordial corporation of many State ecological surveys and various individuals who have contributed information is gratefully acknowledged.

Jan 1, 1942

By Carl H. Beal

The oil industry in the United States is further advanced than in any other country, because of American initiative and the development of industries dependent in some way on petroleum or its products. For this reason the output has constantly increased (fig. 1), and as a result this country has produced more than half of the total output of the world. Trw total past output of the world is approximately 7,000,000,000 barrels of 42 gallons each; of this the United States produced about 4,000,000,000 barrels, or about 57 per cent. The limit of production in this country is being approached, however, and although new fields undoubtedly await discovery, the yearly outpnt must inevitably decline, because the maintenance of a given output each year necessitates the drilling of an increasing number of wells. Such an increase becomes impossible after a certain point is reached, not only because of a lack of acreage to be drilled, but because of the great number of wells that will ultimately have to be drilled. According to figure 1, the daily production per well each year has increased during the last few years. However, this increase is abnormal, being caused by the new pools brought in. Although such a condition may continue for several years, the average production per well will finally begin to decrease on account of the lack of new pools to make up for the normal decline in production of the old ones.

Jan 1, 1919

By L. R. Herrmann

The research described in this report is the first phase of a comprehensive program for the development of a characterization for the structural properties of rock masses. The mathematical expression of the characterization is especial' tailored for use in conjunction with modern structural analysis procedures. The objective of the first phase of the project is to determine the feasibility of representing the structural properties of rock masses in terms of the analysis of an appropriate "representative volume" the results of this investigation are described in detail in the body of the report. The current state-of-the-art concerning the understanding and description of the fundamental mechanisms of rock behavior are determined from a survey of existing literature. The development of a representative volume that captures the most important of these mechanisms is described, In order not to unduly obscure the fundamental aspects of this development, the mathematical analysis of the representative volume is limited to plane strain conditions. A subroutine for the numerical evaluation of the proposed model (i.e., the analysis of the representative volume) is presented. The steps necessary for the incorporation of the subroutine directly into existing two-dimensional finite element structural analysis programs are described. Comparisons between the predictions of the proposed characterization and published results of simple laboratory tests are presented and discussed. Finally recommendations are given concerning suggested improvements of the model and the extension of it to the general three-dimensional case.

Jan 1, 1974

By R. A. Hatch

The United States depends mainly on foreign imports, principally India, for an adequate supply of sheet mica suitable for its many uses in the electrical and electronics industries. Sheet mica has, in fact, played an indispensable role in developing these industries,4/ and, in turn, the products of these industries (radio, radar, electric motors, and many others) have become indispensable to the military forces. Because or these conditions, sheet mica in its better qualities long has been classified as a strategic and critical material, and from this stems the wide-spread interest in substitute materials of which synthetic mica is one potential type. The United States Departments of the Navy and the Army entered into a cooperative agreement with the Bureau of Mines in 1947 to study ways and means of synthe-sizing and growing mica crystals. This is one of a series of reports5/ that describe the results of this program.

Jan 1, 1956

By D. G. Willard

The U.S. Department of Interior, Bureau of Mines has evaluated the potential resource and annual availability of cobalt from 27 deposits or districts in 11 market-economy countries. More than 95 pct of primary cobalt production from market-economy countries, mainly byproduct output from copper and nickel operations, was analyzed. Approximately 1,200,000 mt of cobalt is potentially recoverable at the demonstrated resource level. Very large additional resources exist, especially in laterite deposits, but are at the inferred level. The producing operations evaluated in this study are expected to produce about 19,000 mt of cobalt in 1989, significantly less than the available capacity of about 31,000 mt. More than 14,000 mt per year of cobalt is produced from copper-cobalt deposits in Zaire and Zambia, of which 11,000 mt can be produced at a copper price of $O.60jlb or less with a O-pct discounted cash-flow rate of return (DCFROR). Approximately 4,400 mt of cobalt is produced annually from nickel-cobalt deposits in six countries, of which about 1,800 mt (in Canada and Brazil) could be produced at a nickel price of $1.50jlb or less at a D-pct DCFROR. Approximately 200 mt per year of cobalt is produced from a cobalt mine in Morocco. Most of the evaluated nonproducing operations and prospects that could potentially produce cobalt as a principal product or byproduct would require a total cost (including a 15 pct-DCFROR) significantly exceeding January, 1989 market prices of the principal commodities. Principal-commodity dependence, transportation routes, cobalt toxicity, and other issues that could affect the availability of cobalt are addressed herein.

Jan 1, 1991

By R. J. Pokora

This Bureau of Mines report is an applications manual that can be used by the nonmetallic mining industry for guidance in installing noise control materials into crushing and screening plants. These noise control modifications were installed and successfully tested at three operating quarries. This report identifies the major noise sources that can be encountered in crushing and screening plants, and discusses the applicable noise control materials and techniques that a plant operator can utilize on a retrofit basis to reduce equipment noise.

Jan 1, 1984

By Fermont F. Clarke, Others, Paul Zinner

"INTRODUCTION The Edison mine comprises workings on two irregular spodumene-bearing pegmatite dikes which outcrop near the town of Keystone in the southern portion of the Black Hills of South Dakota. The Bureau of Mines conducted an investigation of the Edison mine as part of a comprehensive study of the lithium mineral-production possibilities in the Black Hills area. The work was undertaken during the Second World War, when the demand for certain lithium salts and compounds exceeded the then small productive capacity of the industry.During the course of the project, the Bureau of Mines completed 13 diamond core-drill holes, aggregating 2,114.5 feet of drilling. Twenty-six cannel samples were taken from the main Edison shaft, and 13 miscellaneous samples were obtained to permit analysis of the efficiency of phases of mining and sorting operations. Metallurgical tests were made by the Bureau of Mines to investigate the feasibility of beneficiating spodumere-bearing ores from the Edison mine. 3/"

Apr 1, 1948

By W. H. Frederic, A. C. Fieldner, W. A. Selvig

"Low-rank coals have a pronounced tendency to disintegrate or ""slack” when alternately dried, and wetted by exposure to the weather. The more readily a coal slacks the greater is its tendency to ignite spontaneously and the more care must be used in its shipment and storage. Lignite slacks very readily when exposed to the weather. Slacking trouble is also experienced in shipping and storing subbituminous coal, but not to the same extent as with lignite. As a rule, bituminous coals are only slightly affected by weathering and in general may be classified as nonslacking coals. The slacking tendency of subbituminous coal is one of the characteristics that is used to distinguish it from bituminous coal. An accelerated laboratory method of test was developed to measure such slacking tendencies. This method was applied to a number of coals, principally from the State of Washington, and the method and the results obtained are given herein.Helpful information concerning slacking tendencies of coal was received from Marius R. Campbell, senior geologist U. S. Geological Survey.Coals that slack readily contain relatively large amounts of moisture. When exposed to the weather such coals lore moisture rapidly. As the coal loses moisture at the surface there is a gradual drift of moisture from the interior of the piece to the surface. If the loss of moisture at the surface proceeds at a faster rate than it is replaced by moisture from the interior of the coal piece, there undoubtedly in greater shrinkage of the coal at the surface as tom-pared to the interior of the piece and stressed are generated in the surface coal.These stresses in the surface coal cause it to crack and disintegrate.Likewise, when the air-dried coal is wetted by rain, the exposed surface of the coal pieces gain moisture more rapidly than the interior of the piece, causing greater expansion in the surface coal and the coal breaks down further. As this process of air drying and wetting is continued when the coal is exposed to the weather, the slacking proceeds and the exposed lumps of coal may disintegrate completely."

Nov 1, 1930

By R. H. Church

As part of the research effort of investigating the effects of microwave energy upon the chemical and physical properties of different minerals and ores, the Bureau of Mines has conducted basic research into identifying those properties of minerals that are affected by microwave energy, namely, the dielectric constant and loss tangent. These properties were determined utilizing the theory of microwave propagation in a coaxial waveguide filled with a dielectric material and measuring the input impedance with an RF impedance analyzer that operates from 1 MHz to 1 GHz. By knowing the microwave frequency and filling the waveguide with a powdered mineral, the dielectric properties of the mineral sample were determined. From these dielectric properties, theoretical microwave heating characteristics of each mineral could be calculated. These same mineral samples were then irradiated by a 915 MHz 30 kW variable power microwave oven and dielectric heating studies were performed. A comparison of the theoretical heating characteristics and the results from actual dielectric heating studies was conducted to evaluate the dielectric property measurements on each mineral. This report presents the results of the Bureau's research in identifying the dielectric properties of low-loss minerals according to the mineralogical classification scheme along with their irradiation studies. Though far from complete, this study represents some of the more frequently encountered low-loss minerals.

Jan 1, 1988

By H. Kenworthy

Small batches of fluorspar flotation concentrates were made into nodules and pellets on a laboratory scale. Several of these were rated acceptable by laboratory evaluation methods. The most satisfactory pellets were produced by mixing fluorspar with about 12.5 percent of water, by weight, and 4 percent of organic binders. These binders) for the most part) originated from petroleum and wood-pulp industries. They were generally difficult to handle and were not easily incorporated with the fluorspars tested. Most of them seemed to have an aversion for damp fluorspar and had to be forcibly mixed with the fluorspar; which was then formed into pellets by pressure. Substitution of fuel oil in varying amounts in the binders enhanced the mixing and penetrating qualities of these binders but at the same tire tended to make the pellets more porous. Tall oils performed the same function to a lesser degree and usually decreased the water absorbency of the finished pellets. Heat-treating temperatures to set up these binders were moderate -about 5000 F. for 30 to 50 minutes was usually enough for both drying and heat treating. Nodules made with 1-1/2 to 2 percent of bentonite as a binder were easily mixed and formed. They required a high degree of heat (about 1,500° F.) to develop their strength and were quite water-absorbent when finished. Two fluorspars were examined for weight and fluorite loss after heat treatment at similar temperatures. Both showed a definite wej.ght and analytical loss of fluorite. Bentonite was used also as a binder to successfully nodulize finely ground oxides of iron, manganese, and nickel.

Jan 1, 1951

By Lowell B. Moon

The Stange and Byrnes Heirs manganese mines, adjoining properties in Bland and Giles Counties, Va., have produced at least 20,000 long tons of concentrates containing 8,000 long tons of manganese. They were selected as the site for a strategic-mineral development project because of the existence of geologic possibilities for extensions of the known ore body. In plan, the long dimension of the ore body parallels the axis of a major anticline. Localization apparently is due to longitudinal and transverse fracturing incident to two-way folding. That the manganese oxides were deposited by downward-moving solutions is suggested by the fact that mineable concentrations are confined to a coarse, porous sandstone under-lain by impervious silt and clay. Bureau of Mines project work began on January 15, 1941, and was completed on April 23. The work sampling the faces of the pit, bulldozer trenching, and churn drilling. Pit sampling consisted of 132 channel samples usually 5 feet long and taken at 20-foot intervals. Seventeen trenches aggregating some 4,500 feet in length were dug by the bulldozer. Trenches averaged 12.6 feet in width and 5 feet in depth. A total of 1,978 feet of churn drilling was done in 33 holes. In preparation for churn drilling it was necessary to construct roads to 21 of the 33 sites. A total of 2,867 linear feet of road averaging 13 feet in width was built.

Jan 1, 1950

By Ronald B. Stotelmeyer

This report summarizes studies of 28 National Forest roadless areas in Montana completed by the U.S. Bureau of Mines (USBM) in the period 1974-1993. It also briefly describes 20 areas for which field studies have not been conducted. All 48 of these roadless areas have been recommended for addition to the National Wilderness Preservation System or proposed as special management areas by the U.S. Forest Service (USFS) or the Montana congressional delegation. The Bureau studies indicate which parts of the roadless areas have a high likelihood for mineral-resource development. They also show where mineral production has occurred in the past and where abandoned mine workings (possible hazards) would be encountered. The number of mine and prospect workings found are a measure not only of surface disturbance, but of areas not wilderness in character. For the purposes of this report, mine refers to a property which produced (or is currently producing) a mineral commodity, a prospect is a property which has been explored but has no record of production.

Jan 1, 1994

By John C. Ferm

This report contains a summary of Phase I and complete results of Phase II portions of a study of geologic factors associated with roof falls in mines on the Pocahontas #3 coal seam in southern West Virginia and southwestern Virginia. Principal objectives of Phase I was the selection of five mines that best portrayed the spectrum of roof and mining conditions and Phase II consisted of a measurement and documentation program for each of the five mines. The documentation measurement program included reconnaissance mapping, detailed mapping, joint measurements and coring roof rock. 1.2 PHASE I RESULTS The results of Phase I consisted of the selection of the following five mines for detailed study: Virginia Pocahontas #3 (Island Creek Coal Company), Bishop (Consolidation Coal Company), Shannon Branch (Allied Chemical Company), Keystone II (Eastern Associated Coal Company) and Macalpine-East Gulf (Westmorelenad Coal Company). In addition, Phase I results, which were based on questionnaire data, indicated that the kind of rock in the roof --gray sandstone, crystallized sandstone, laminated sandstone and shale, grey shale, slickensided shale, and rider seams could be associated with good and bad top areas. Also presence of vertical separations, bolt length, entry and cross-cut width, length and torque on bolts and depth of overburden seemed to be related factors. These data provided a focus for the Phase II measurement program.

Jan 1, 1975

By R. P. Walters, M. J. Lynch, D. R. Flinn

The Bureau of Mines evaluated tthhee feasibility of substituting platinum- coated metals for bulk platinum shapes as a means for conserving platinum . Platinum coatings were prepared using four different methods of electrodeposition , then tested and evaluated . In order for platinum coatings to be useful in process environments , they must be thick , adherent , stress - free , and pore - free . The Bureau evaluated direct - current , current reversal , cathode shielding , and pulsed- current plating techniques for producing a pore-free platinum electrodeposit from a molten cyanide bath . Aqueous corrosion tests of Fe - 10Cr substrates coated with approximately 25 μm of platinum showed that pulse plating yielded the most corrosion- resistant and , hence , the most pore -free coatings . The morphology of coating cross sections was in all cases columnar . The average grain size of pulse -plated deposits was independent of thickness , while all other plating techniques produced grains that increased in size as the coatings became thicker . It is believed that the constant grain size in the pulse - plated deposits resulted from better mass transport during the electrodeposition .

Jan 1, 1965