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By Arne Landsberg

A study of the chlorination kinetics of germanium, silicon, iron, tungsten, molybdenum, columbium, and tantalum has been made to determine the effects of temperature, chlorine concentration, geometric surface area and gamma radiation. The reaction products were volatile at the temperatures used this making it possible to follow the reaction rates by weight loss of the solid. Chlorination rates of germanium, silicon, and iron were found to be directly proportional to chlorine concentration while the rates for tungsten, molybdenum, columbium, and tantalum were proportional to the 0.5 to 0.6 power of chlorine concentration. A good correlation of reaction rate and geometric surface areas was not obtained because the true surface area of the samples could not be measured. Intense gamma radiation had no effect on reaction rates. The Arrhenius activation energies determined over the temperatures used are as follows: Germanium, 27 kcal/mole (233°-241° C); silicon 33 kcaL/mole (375°-517° C); iron, cold rolled, 20 kcal/mGle (259°-325° C) annealed, 21 kcal/mole (293°-337° C); tungsten, 43 kcal/mole (617-776° C); molybdenum, 37 kcal/mole (445°-4910 C); columbium) 34 kcal/mole (229°?255° C); and tantalum, 29 kcal/mole (370°-449° C).

Jan 1, 1965

By G. E. McElroy

This report discusses the construction and use of an all-pressure psychrometric chart in which the requirements of simplicity of appearance and absolute accuracy have been waived, to a certain extent, to provide for the rapid determination of psychrometric data and for the rapid solution of air-conditioning problems of major interest to the mining industry. Many mines in which air-conditioning problems are important are situated at elevations far above sea level and embrace great differences in elevation - in excess of 8,000 feet in certain mines - throughout their airflow circuits. Under these conditions, the effects of variations in the pressure of the atmosphere upon the physical properties of the mixture of air and water vapor of which it is composed are considerable and should be taken into account in the solution of problems. The simple types of psychrometric charts in common use, such as the Carrier, Bulkeley, Hill, and Goff (American Society of Heating and Ventilating Engineers Guide), are not generally suitable, in that they are drawn for a single barometric pressure - 29.92 inches mercury.

Dec 1, 1947

By A. N. Fried

With the growing importance of fluid injection in recent years, the petroleum industry has been investigating and field- testing a variety of new methods designed to modify the physical properties of reservoir oil to improve the efficiency of gas and water injection. These procedures include condensing-gas drive, LPG (liquefied petroleum gas) injection, alcohol-slug process, high-pressure-gas displacement, detergent-solution flooding, and in situ combustion (30, 37).3 A new and different method to increase the effectiveness of gas and water injection has been tested by the Bureau of Mines, Consideration of both fundamental and practical factors that operate to limit the oil recovery attain- able by conventional oil-displacement mechanisms led to the concept of a displacement mechanism called the foam-drive method. This report describes the experimental study that tested this concept in the laboratory.

Jan 1, 1961

By N. A. C. Smith, A. C. Fieldner, R. R. Sayers

Gases and vapors given off by petroleum and its products have long been recognized as somewhat injurious, when inhaled in high enough concentrations. The petroleum industry has recognized these effects and has tried to minimize the possibility of employees encountering dangerous concentrations of the vapors. Petroleum gases and vapors have not, however, been considered as actively poisonous, in the sense that hydrocyanic (prussic) acid and phosgene are poisonous; men have been exposed to them repeatedly, and for long periods, without any marked ill effects. Light Mexican crude oil when first introduced into the United States for refining was handled in much the same way as was customary with other apparently similar crudes; but experience soon showed that some toxic substance escaped from the crude during production and transportation and in most of the refinery operations. After a preliminary investigation several of the larger companies decided that the gases from the petroleum were the source of trouble, and therefore took precautions, wherever possible, to protect the men from exposure to these gases. With the increasing use of Mexican crude, this problem has become important. The present report covers the work done on the subject by the Bureau of Mines and the Public Health Service under a cooperative agreement with the American Petroleum Institute.

Jan 1, 1925

By Paul M. Tyler

The outstanding trend in the graphite market is the fast-growing demand for cheaper qualities of graphite and the declining consumption of the more expensive varieties. The manufacture of graphite, crucibles for melting metals was one of the earliest applications of the-mineral and for many years constituted by far the leading source of demand. In later, years, however; and more especially since the Great War, the increasing demand for high-grade steel ingots and castings instead of enlarging crucible sales has permanently curtailed the domestic demand for crucibles because it has hastened the introduction of electric, oil or gas fired furnaces to replace the older types requiring pots to hold the metal during melting. While there has been a substantial increase in the use of graphite for miscellaneous refractories the total consumption for such purposes is too small to offset the shrinkage in demand for crucible making, and though it consumes the better and hence more expensive grades of crystalline flake graphite, it does not call so insistently for the still costlier Ceylon grades.

Jan 1, 1929

This report describes the new Bureau of Mines Core Repository System (CORES) and presents the methods for selecting, processing, and storing physical samples and descriptive data for future reference by earth scientists. The system preserves splits of chip samples and longitudinally sliced segments of core. A records retrieval system provides for storage of data on microfilm and magnetic tapes and uses the keysort parameters of location and commodity for the identification of data.

Jan 1, 1978

By Robert Lee Stahl

Comprehensive field tests were made by the Federal Bureau of Hines at the Conda open pit mine near Soda Springs, Idaho, to determine whether surface geophysical techniques could be used to detect and delineate faults in phosphate deposits. The tests included seismic refraction, magnetometry, electrical resistivity, and airborne photography. Of the several geophysical techniques tested in the field, horizontal resistivity profiling was the most effective method for diagnosing faults. The method is quick, inexpensive, accurate, and can be easily used by mining company personnel to detect and delineate faults.

Jan 1, 1975

By David C. Oyler, Hakan Gurgenli, Gregory M. Molinda

Historically, miners have known that roof rocks originally composed largely of mud were prone to slaking and deterioration when exposed to water and humidity. Mine Safety and Health Administration (MSHA) records show that roof falls are more prevalent in summer and late fall. Field data shows higher bolt loads and increased room convergence in summer months. Laboratory data shows that very high internal pressures can be generated by significant strain in clay-rich rocks. In summer months humidities ranging from 70-100% can cause rock strains up to 7%, and rock pressures of 14,000 psi, more than enough to break apart weak shales and fireclays. The National Institute for Occupational Safety and Health (NIOSH) conducted wet/dry immersion cycling of clay-rich rocks. Results show that the rocks most prone to moisture deterioration are fireclays, claystones, and sandy shales, all of which have disrupted bedding. Of the 7 mudrocks with a weatherability index above 40%, none showed consistent fissile bedding. Black shales were surprisingly resistant to wet/dry water immersion cycling. Generally, mixed rocks (stackrock), typically susceptible to horizontal stress, are more resistant to moisture-deterioration. Mine roof rocks tested with moisture sensitivity ratings above 50% (moisture sensitivity index ranges from 0-100 with 100 being the most sensitive) all came from mines which had roof skin problems and used supplemental support to prevent rock fall injuries. Some roof rocks showed lateral variability of moisture sensitivity values, suggesting the need for more samples in highly varying roof rocks. Swelling strains of mudrocks showed that almost all of the swelling occurred in the first 24 hours after immersion. The wet/dry immersion cycling test used provides an accurate, quick and inexpensive method for estimating the moisture sensitivity of mudrocks. With this information mine operators can begin to anticipate hazardous ground and prepare appropriate roof support.

By J. D. Davis

THE CARBONIZING properties of Chilton-bed coal from Lorado No. 5 mine, HE Logan County, W. Va., were determined by Bureau of Mines-American Gas Association tests at 600°, 700°, 800°, 900°, and 1,000° C. and by expansion tests. Chemical analyses, agglutinating and plasticity tests, and low- and high-temperature assays also were included in the investigation. Blends with low-volatile Pocahontas No. 3 coal were carbonized at. 900° C. The Chilton coal bed lies in the Kanawha, or Upper Pottsville formation of the Pennsylvanian system; the estimated original reserves are nearly 3.2 billion tons. The bed was 39/1 to 57 inches thick in the Lorado No. 5 mine, and the coal was 38 to 57 inches thick. The carbonization sample contained 62.6 percent fixed carbon on the dry, mineral-matter-free, basis, and the heating value on the moist, mineral-matter-free basis was 15,190 B. t. u. per pound; it therefore ranks as high-volatile A bituminous. It contained 1.8 percent moisture, 35.2 percent volatile matter, 57.9 percent fixed carbon, 5.1 percent ash, and 0.7 percent sulfur, as carbonized. The sulfur was largely organic, and the ash softened at 2,630° F. The agglutinating value determined on a silicon carbide-coal mixture of 15:1 was 6.8. In the Gieseler test the coal softened at 327° C., fused at 407° C., attained a maximum fluidity of 5,730 dial divisions per minute at 435° C., and solidified at 487° C. Maximum resistance in the Davis plastometer was 45.5 pound-inches.

Jan 1, 1951

By Lawrence W. Scott

The performance of RETIMET metal foam as a flame arrester on explosion-proof enclosures was investigated by the U.S. Bureau of Mines both in laboratory tests and at the U.S. Mine Safety and Health Administration's (MSHA's) Approval and Certification Center, Triadelphia, WV. The objective of this research was to develop a permissible pressure vent for use on lightweight, vented, explosion-proof enclosures. In laboratory tests, four grades of RETIMET, a stainless steel foam material, were evaluated: (1) 45 NC-7, (2) 45 NC-13, (3) 80 NC-7, and (4) 80 NC-13. Explosive gas mixtures were prepared by a dynamic flow system. Ignition was by a low-voltage arc. Each grade of RETIMET metal foam successfully arrested the flame front in all methane-air tests. To evaluate RETIMET metal foam on large, commercial size enclosures,a multi compartmented enclosure was designed and tested in MSHA's explosion gallery in Triadelphia, WV. Extensive explosion testing revealed that a minimum vent-area-to-enclosure-volume ratio of 11.33 in2/ft3 is required to keep internal pressure rises below 3 psig. The RETIMET metal foam functioned satisfactorily in all tests as evidenced by the absence of external ignitions.

Jan 1, 2010

By Charles M. Keenan

THIS PUELICATION lists and provides brief accounts of the major disasters not classified as explosions of gas or dust that have occurred in the cod mines of the United States from the earliest times to the present. Together with an earlier publication of the Bureau2 it provides information on all the known major coal-he disasters (disasters causing five or more deaths) in this Nation's history. Sources of each account are given individually. In each account the actual words of the original publication are used unchanged, but sentences or paragraphs referring to details that are not significant have been omitted. In those few cases where conflicting data were reported in different publications the selected version is the one that appears most logical and which in general is in agreement with most of the other accounts.

Jan 1, 1963

By R. O. Dannenberg

The Bureau of Mines conducted laboratory investigations with the objective of developing an alternative process for recovering cobalt and copper from complex sulfide concentrates. Processes currently used depend largely upon precipitation techniques to remove impurities and recover cobalt from sulfate liquors prepared by oxidative pressure leaching of the sulfide concentrates. The Bureau conducted bench-scale research on a process for treating cobaltite concentrates, comprising (1) oxidative pressure leaching, (2) jarosite precipitation followed by H202 oxidation and pH control to remove iron and arsenic, (3) copper solvent extraction with a mixed hydroxyoxime-amine extractant, (4) copper electrowinning from recirculating acidic strip liquor, (5) selective cobalt extraction from copper solvent extraction raffinate with a phosphinic acid extractant, and (6) electrowinning of cobalt from a recirculating weak acid strip liquor. Overall cobalt and copper recoveries were 91.7 and 84.1 pct, respectively. Electrowon products assayed 99.8 pct Co and 99.89 pct Cu.

Jan 1, 1987

In 1987 Wyoming became the largest coal producing state in the country. The state is known for its extensive coal resources and extremely thick coal seams. Wyoming's coal reserves total about 69.3 billion tons, or 14.2 percent of the U.S. coal reserve. Coal seams range generally from 10 to 80 feet in thickness, although one seam is 220 feet thick. The coal-bearing areas of Wyoming underlie approximately 41 percent of the state's total land area. Wyoming's coal ranges from lignite to high volatile bituminous. Most of the coal produced is subbituminous from the Powder River coal region near Gillette. The presence of coal in Wyoming was discovered before 1834 on the Belle Fourche River. The state's first mine opened in Carbon County in 1865, and with the completion of the trans- continental railroad, the demand for coal increased. Currently approximately 80 percent of Wyoming's coal production is shipped out-of-state to meet the growing demand for low- sulfur coal to fuel electric generating plants. Wyoming received conditional regulatory approval November 26, 1980. Its Abandoned Mine Land Program was approved February 14, 1983.

Jan 1, 1992

By Alden H. Emery, J. J. Forbes

"IntroductionThe data contained in this paper were collected during the course of an investigation which covered 15 representative coal mines in 6 coal-mining States. The purpose of the investigation was to determine by atmospheric sampling how much dust was raised into the air during the various operations of coal mining, such as undercutting with machines, loading coal by hand, and transporting it from the working face to the surface. The data thus obtained were considered from two angles - namely, the possible physiological effect of inhalation and the explosion hazard of the dust. No attempt will be mode to discuss the former factor in this paper.CONDITIONS OF MININGThe mines in which this investigation was conducted were considered representative, and it is believed that the results obtained will suffice for the average dustiness encountered in most coal mines. .All of the coal mined was bituminous, from beds 30 to 120 inches thick. Only the ordinary room-and-pillar system of mining was employed. Daily production ranged from approximately 700 to 1500 tons and the men employed from 150 to 450. Coal was undercut by short-wall mining machines in all mines, with the exception of one in which pick mining was employed. Loading at the face was done by miners; none of the mines used mechanical loaders. Electric drills, both for brushing roof and for shooting coal, were commonly used although some roof work was done with jack-hammers and a. little of both with augers. Coal was hauled by motor, mule, or rope power in end-gate cars with capacities ranging from 1600 to 3600 pounds. With few exceptions, coal was won at the face by dry methods - that is to say, no water was employed fox wetting down the dust either during undercutting, loading, or transportation."

Feb 1, 1927

By Lance R. Barron

Over the past decade, the U.S. Bureau of Mines (USBM) has studied longwall gate road stability at four mines in the Book Cliffs and Wasatch Plateau Coalfields of Utah. These operations are characterized by multiple-seam mining, abruptly varying cover depths to 914 m (3;000 ft), and massive rigid, sandstone units in the main roof or floor. Such conditions encourage severe bumping, roof instability, and occasional floor heave problems.' Various gate road configurations have been employed to alleviate' these problems. Although the mines have comparable basic conditions, the lithologies and qualities of the immediate roof, floor; and seam ate different in each mine and often vary in a single mine. Gate road systems that mitigate hazards in one mine may prove inappropriate in another or for different areas of the same mine. This report relates the geology of the coalfields; describes the location, geologic setting, specific mining conditions, operating history, and the USBM field study and results or conclusions for each mine; summarizes the relative performance of the gate road systems; and emphasizes the need for site-specific geotechnical data to evaluate gate road conditions and performance.

Jan 1, 1994

By R. G. Burdick

The problems presented by old mine workings affect both present day mining and land development. An automated method of locating these old mines from the surface using electrical resistivity techniques was de-veloped earlier under a Bureau of Mines contract. Subsequent Bureau research has refined the techniques and expanded the area of study to a variety of geologic provinces. During this research, six mining areas in the United States were in-vestigated with the Bureau's automated resistivity method. This report describes the mining areas involved and the results of the resistivity investigations, which showed a high rate of success in detecting old mines. It also describes the field measurement techniques and data analysis procedures.

Jan 1, 1986

The Minerals Data Source Directory is a compilation of descriptive information on the availability, content, and location of minerals data in the Federal Government. It is intended to assist Government personnel and the general public in locating and acquiring minerals information. Included in the Directory are descriptions of data bases, publications, information systems, and information offices containing data pertaining to ail aspects of mineral production, consumption, trade, and related information. These mineral data sources include the Federal agencies such as the Department of the Interior's Bureau of Mines and Geological Survey whose major mission is the collection and dissemination of mineral information. Also included are agencies such as the Departments of Agriculture, Commerce, Labor, State, Transportation, and Treasury, the Central Intelligence Agency, the Environ- mental Protection Agency, the Federal Reserve System, the interstate Commerce Commission, and the Securities and Exchange Commission, whose primary mission is the collection of data in nonmineral subject areas, but in which the mineral industry is a component.

Jan 1, 1983

Unfortunate occurrences resulting in injuries, loss of life, and destruction of property by explosion, fire, and other mishaps during shaft sinking in the past few years have focused the attention of the Bureau of Mines on the need for safety standards for such operations. Several States have some rules and regulations applicable to local conditions, and several Bureau publications (including some now out of print) cover the hazards that may be encountered in shaft sinking. Certain requirements of the Federal Mine Safety Code and Federal Coal Mine Safety Act may be applied, but there are no definite, uniform standards that will guide those desiring to sink a shaft safely and bring about uniform safety inspections.

Jan 1, 1957

By Renpei Yoda

An investigation was conducted to develop columbium alloys with e1evated-temperature strengths higher than those exhibited by more common commercial columbium alloys, and attention was given to improving the oxidation resistance and ease of fabrication. Additions of carbon, aluminum, and chromium were made to some columbium-base alloys, and their effects on workability, recrystallization, oxidation resistance, and mechanical properties at elevated temperatures were explored. The additions were made to take advantage of (1) solid solution strengthening, and (2) precipitation hardening. Three alloys displayed good high-temperature properties with relatively good oxidation resistance at 1,000° C, and tensile strengths from 26,000 to 32,200 psi at 1,400° C. When the properties of these alloys were compared with those of commercial alloys, B-66 and FS-85 (1),4 the outcome was favor-able for the alloys studied in this investigation.

Jan 1, 1967

By M. R. Geer, H. F. Yancey

"INTRODUCTION Throughout the history of coal washing, the jig has been one of the most important coal-cleaning appliances. In 1935 34.7 percent of the 45,361,021 tons of clean coal produced was the product of jigging. 4/ Previous to 1928, most of the jigs used in the United States were of the piston type, with which sufficient mobility to allow stratification in bed is imparted by the reciprocating up-and-down movement of a piston in the water compartment adjacent to the screen compartment. In 1928, the Baum type of jig was introduces in this country and has since come into wide spread use. In this type, water pulsations are imparted by application and release of compressed air to the water compartment. All prior studies of the mechanism of seperating cleared coal from impurity by piston-type jigs. 5/ The same laws of settling, of course, apply to both types, piston or Baum, but the character of the separation with the Baum type may be modified more easily because of the flexibility with which air may be handled, as distinguished from the fixed action of eccentrics commonly used in piston jigs. Since no detailed studies are available to show the performance, that is, the character of the separation between coal and impurity, of the Baum type the Bureau of Mines undertook the investigation recorded in this report."

Jan 1, 1938