Search Documents

By David C. Scott

Between 1990 and 1991, the Bureau of Mines studied the mineral resources of the Kaibab National Forest to appraise the resources present and to determine the types of deposits, and their location. The study included a comprehensive literature search and a limited amount of field investigation of minerals and mining activity in and near the Forest. Small amounts of copper with lesser amounts of gold and silver have been produced from limestone-hosted, strata-bound deposits in the North Kaibab and Tusayan Ranger Districts. In addition to these small metallic deposits, volcanic cinders, pumice, flagstone, and sand and gravel have been quarried in the Chalendar and Williams Ranger Districts. At least ten uranium-mineralized breccia pipes have been identified in the Tusayan Ranger District, One of these, the Canyon pipe, contains a high-grade uranium ore body with associated silver, copper, lead, vanadium, and zinc. The mine permit for the Canyon pipe has been approved and the mine shaft head frame erected.

Jan 1, 1992

By W. P. Yant

A previous report of the Bureau of Mines dealt with the toxicity of dichlorodifluoromethane5, a new refrigerant that has a remarkably low toxicity. Continued research by the Prigidaire Corporation6 and toxicological experiments performed in the Laboratory of Applied Physiology of the University of Cincinnati7 revealed another organic fluoride, dichlorotetrafluoroethane, whose toxicity also appeared to be of a very low order and whose physical-and chemical properties make it suitable for refrigeration purposes. In addition to low toxicity, safety in its use is further enhanced by its physical properties, which permit the design of equipment that operates at comparatively low pressures and hence mitigates the dangers and problems of leakage. The investigation described in this report was performed by the Bureau of Mines at the request and with the cooperation of the Frigidaire Corporation.

Jan 1, 1932

By H. P. Rue

The Bureau of Mines has recently collected two samples of crude oil from wells in the Greasewood Flat area of northeastern Colorado. Sample 31310 was taken from the Continental Oil Co.'s well Briggs No. 1 which care in or September 27, 1931, with a maximum production of 940 barrels per day. Sample 31311 was taken from tie Reiter-Foster Oil Co. Is well Ida Johnson No. 1 which came in on August 24, 1931 with a maximum production of approximately 1000 barrels per day.

Jan 1, 1932

By T. E. Howard

The western phosphate field, comprising parts of Idaho, Montana, Wyoming, and Utah, contains one of the world's largest known reserves of phosphate rock. Although phosphate-rock deposits of good-grade have been known since before the turn of the century and production has been recorded since 1906, real development of this important field did not begin until immediately after World War II. Since then fertilizer-manufacturing facilities using western phosphate rock have been expanded, and three electric-furnace plants for producing elemental phosphorus have been installed, resulting in a rise in mine production from 323,955 long tons2/ in 1945 to 1,653,916 long tons3/ in 1953. Interest in the field is increasing, and it is reasonable to expect that the western phosphate industry will continue to expand. Before 1945 all western production was from underground mines. In that year the first strip mine in the field was started near Montpelier, Idaho,~ and in sub-sequent years a number of other open-pit mines were opened in southeast Idaho and western Wyoming. At present the major part of the production comes from surface mines. Underground mining has continued, and new underground mines have been opened in the field, but recent exploration by operating companies has been aimed primarily at developing additional deposits suitable for low-cost surface mining. Preliminary reserve estimates by the Federal Geological Survey5/ indicate that only a very small part of the total resource may be recovered by surface methods and that the industry eventually must depend largely on underground mining. Because one function of the Bureau of Mines is promoting the conservation and development of the Nation's mineral resources, it is appropriate that research be conducted to develop low-cost maximum-recovery underground mining methods applicable to western phosphate-rock deposits.

Jan 1, 1956

By Raymond Derzay

This publication is intended to be of value to the mineral industry in establishing and maintaining effective programs for preventing noise-induced hearing loss. Factors involved in this loss and the need for and the requirements of an effective hearing conservation program are discussed. The legal and legislative history of compensation for hearing loss is briefly reviewed. A review of statutes is not attempted since several States have recently modified) or are in the process of modifying their laws regarding permissible noise exposures) required hearing protection) and/or compensation for hearing loss. A review of other aspects of the problem of industrial noise in terms of medical, physiological) and psychological frames of reference is included. A hearing conservation program is described in detail. Appendixes detailing the names and addresses of a few equipment suppliers are included. References are provided for those who may wish to delve more deeply into the medical, technical, and scientific considerations of noise and its effect on man.

Jan 1, 1972

By M. E. Tyrrell

Magnesia spinel (MgO.Al203) recovered from dusting slags in the system MgO.Al203-2Ca0.SiO2 is in the form of single crystals most of which will pass 35-mash. This investigation was undertaken by the Bureau of Mines to evaluate the concentrates as a refractory raw material. Three specific types of refractory bricks were studied: (1) dense, (2) lightweight bubble, and (3) insulating. Test specimens ware fabricated 1 by dry pressing, fired to 1,675° C., and tested by procedures common to the industry. The concentrates produced a refractor, having satisfactory density and mechanical strength; however, spinal is sensitive to thermal shock and the possibility of producing a spall-resistant brick using aggregate of such small grain-size must be considered remote. Lightweight refractorias fabricated of spinel bubbles were the most promising of the types tested. They were 30 percent lighter in sight than the dense refractory, their mechanical strength was good, and definite superiority in thermal shock resistance was indicated.

Jan 1, 1962

By E. K. Stanek

This volume describes software developed for programmable calculators that is useful in the analysis and design of mine electrical power systems. The programs are equally useful for any industrial or commercial power system. All programs are written for both the HP-97 and the TI-59 programmable calculators. Listings of both versions of the twelve programs that were developed appear in the report. The programs that were developed can be broken into two groups. The first group encompasses design-oriented programs. The second group encompasses analysis programs. For each program the following items are provided: a description of the program's capabilities, the solution technique used, instructions on how to use the program, a worked out example with data and results and, finally, listings of the programs for the HP-97 and TI-59 programmable calculators. Typical problems that can be attacked with these programs include ground bed design, selection of contactor size, fuse size, relay settings, instantaneous overcurrent trip settings for trailing cables, allowable cyclic cable loading, short circuit analyses, prediction of transient voltages and others.

Jan 1, 1979

By H. C. Carpenter

Data are presented comparing results obtained with 17 different catalysts in hydrogenating crude shale oil to gasoline in single-pass operation. A method is described for predicting the maximum yield of gasoline obtainable at constant pressure for each catalyst from results of a limited number of experiments at different temperatures. Operating variables have considerable influence on yields and properties of products. With most of the catalysts, at operating temperatures below 890° F. liquid yield exceeded 100 volume-percent. Above this temperature the volume of liquid product decreased rapidly. Maximum gasoline production in most instances was achieved at a temperature higher than that at which the maximum volume of liquid product was produced.

Jan 1, 1959

By W. M. Dressel

The Federal Bureau of Mines has obtained data by differential thermal analysis of the various minerals that represent the nation's resources in manganese. These data are supported by X-ray diffraction analysis, chemical analysis, mineralography, and optical mineralogy, and provide fundamental information on the response of each mineral to thermal treatment in oxidizing, reducing, and neutral atmospheres. The information can be applied advantage¬ously in the identification of manganese minerals. Its greatest potential value, however, lies in the application of the quantitative data on the reaction temperatures, rates, and products to the more efficient extraction of manganese from U.S. ores. Thermal analysis curves are presented for certain manganese minerals, namely hausmannite, bixbyite, braunite, pyrolusite, lithiophorite, cryptomelane, hollandite, manganite, rhodochrosite, and rhodonite. The original minerals and the products of their thermal decomposition were identified by X-ray diffraction analysis, supplemented by chemical analysis and mineralogical identification.

Jan 1, 1961

By J. D. Davis

"Introduction.Sixty years ago, M. Berthelot found that ethylene could be selectively absorbed from gaseous mixtures by concentrated sulphuric acid, and that the compound formed by the chemical union of the gas and acid was readily decomposed by heating with water, yielding ethyl alcohol. Only within the last few years has there been any attempt to make use of this discovery technically.Bury*, working in England at the Skinningrove Iron Works and on a commercial scale, developed a technical method for converting, the ethylene of coke-oven as into alcohol. With a gas containing less than 3 per cent of ethylene, he obtained a yield of 1.6 gallons of alcohol per ton of coal carbonized.De Loisy** perfected a technical method for treatment of coke-oven as for alcohol. Evidently this work was carried out on a semi-commercial scale. His method is based on the use of catalytic agents for hastening the absorption of ethylene by sulphuric acid. He uses part of the spent acid for drying the gases and pact for the manufacture of ammonium sulphate. Excess acid is reconcentrated by waste heat. Others have worked on the problem, but so far there has been no large recovery of ethylene from coke-oven gases. The chief difficulty seems to lie in the low efficiency (about 50% of methods and tae relatively low concentrations of ethylene in the gases treated. Gas from Trent amalgam*** contains much larger percantages of ethylene than does coke-oven gas, as Will presently be shown, and if it should ever prove practIcal to treat industrial ;as for alcohol, this gas would offer attractive possibilities,* Bury, Ernest, Ethylene as Alcohol from Coke-Oven Gas: Gas Journal' Vol. 148, D. 30, 1919, pp. 718.** DC Loisy, M.E., Sur un procede' industrial de fabrication syntlotique de l'alcool et de l'ether a partir des gaz de distillation de la houil Comp Rend, vol. 170, Jan. 1920, p. 50-3.*** A paste consisting of approximately part oil such as that obtained as for cleaning coal. See Perrott. in cleaning coal, Chem 3 parts finely pulvarized coal and 1 final product in the Trent, process StJ, and Kinney, S.P. The use of oil Vol. 35 August 3, 1921, p, 183.. & Met."

Nov 1, 1922

By Frank C. Morris

It is generally recognized that the productivity and ultimate recovery of an oil well may be reduced as a result of reduction in permeability of the sand at the well bore by invasion of filtrates and clay particles from drilling fluids. As a means of determining whether a sand has been "damaged" from these sources, several investigators2 3 4 5/ have developed methods of analysis based on the rate of increase in bottom-hole pressure while a well is shut in. Because of growing recognition of the importance of completion practices as related to the quantity of oil that may be recovered from wells, the Bureau of Mines has studied completion practices in California and the Midcontinent area. Well-interference and pressure-buildup tests were completed Ear seven wells in the Scurry Reef field to determine the effective permeability in the reservoir.6/ Also, a study was made of the pressure-decline curves obtained from 35 water-input wells in 5 different production areas of northeastern Oklahoma and eastern Kansas.7/

Jan 1, 1957

By D. D. Southworth

In 1981, 1982, and 1983, the Bureau of Mines examined the potential for lode deposits of platinum-group metals (PGM) in the Goodnews Bay ultramafic complex, Alaska. The complex consists of the Red Mountain, Suzie Mountain, and Smalls River ultramafic bodies and displays concentric zoning of rock types similar to complexes in southeast Alaska, British Columbia, and the Ural Mountains in the U.S.S.R. Results of the study indicate that platinum is preferentially associated with chromite and magnetite in the dunite core of the complex, and palladium is preferentidlly associated with sulfide minerals in the outer clinopyroxene-rich zones. the most promising targets for PGM lode deposits are the chromite-rich dunite at the heads of Fox Gulch and Squirrel Creek and iron-nickel and iron copper sulfide-bearing magnetite clinopyroxenite and hornblende-rich rocks outward of the dunite core, also in the Fox Gulch-Squirrel Creek area. Significant placer reserves are present in the unmined, deeply buried placer ground in the lower Salmon River Valley, and also in tailings from previous dredging.

Jan 1, 2011

By Donald J. Ninteman

This Bureau of Mines publication is a literature study of the problem of spontaneous oxidation and combustion of sulfides in underground mines. It summarizes the present-day hazards, process mechanisms, and prevention and control techniques of this growing problem in underground mines. The iron sulfides generally have the greatest tendency to oxidize, particularly pyrrhotite. The presence of moisture and oxygen is essential for the oxidation reaction. Highly fractured sulfides, when found with timber or combustible refuse in slowly circulating air, pose the most serious fire hazard. Quenching with water is effective in quickly dealing with local hot spots, but ventilation at high flaw rates is the most effective and economical means for long-term prevention and control.

Jan 1, 1978

By J. B. Clemmer

This report summarizes the results of u laboratory study of the beneficiation of Arkansas bauxite by flotation. Although the investigation is not yet completed, a preliminary retort of the results on several typical bauxites is presented to show the merits rind limitations of flotation for the production of concentrates acceptable to the aluminum industry. It is

Jan 1, 1941

By M. B. Boyer, C. H. Herty, F. A. Hartgen, G. L. Frear

"DEFINITION OF VISCOSITYViscosity has been defined as the resistance experienced by one portion of a liquid moving over another portion, such as one molecular plane moving over an adjacent plane. A measure of viscosity is the force required to keep one plane in motion at Unit velocity, the other plane being considered stationary. Figure 1 illustrates the general idea that the surface friction between two adjacent areas will be greater the larger the molecules. Therefore it may be assumed that viscosity will be increased by molecular association or agglomeration, and likewise dissociation rill decrease viscosity. According to Maxwell (1)6 the unit of viscosity, the poise, is the tangential force per square centimeter of area of either of two horizontal planes 1 centimeter apart, one of which is fixed while the other moves with unit velocity, the space between being filled with viscous liquid of unit viscosity.The need for a satisfactory apparatus and experimental procedure for the determination of viscosity of high-melting materials at temperatures corresponding to those in pig-iron and steel making has been recognized during the past few decades. The condition of the slag during the smelting and refining periods in the iron- and steel-making processes exerts an important influence on the metal product obtained, this slag condition really meaning the state of viscosity or, vice versa, fluidity, which the slag attains under certain conditions."

Jun 1, 1934

By H. J. Heinen

The Bureau of Milts studied repetitive batch electrowinning of molybdenum from molybdic oxide ) to determine the effects upon the electrolyte life, purity of metal product , and overall cell performance. The electrolyte consisted of 54.0 weight-percent sodium tetraborate (Na2B407), 23.6 weight-percent sodium chloride (NaC1), 14.9 weight-percent sodium fluoride (NaF), and 7.5 weight-percent Mo03. The feed materials were pure and technical-grade Mo03. Electrolysis was conducted at l,000° C in a graphite cell in an atmosphere of air and carbon oxides. Electrolyte degradation did not occur during repetitive winning of molybdenum from pure Mo03 in an 8-day (5,400-ampere-hour) period of operation. Electrowon metal contained <0.1 percent total impurities. The electrode configuration is a key factor in the direct conversion of technical-grade Mo03 to metal by repetitive cyclic electrolysis. The best configuration found was a cathodic crucible and a central anode. Metal purity of 99.8 percent and a current efficiency of 91 percent were maintained until the combined impurity buildup the electrolyte reached 4.7 percent silicon, l.0 percent aluminum, and 0.6 percent iron. One pound of molybdenum was produced per 1.5 pounds of solvent salts employed. About 25 percent of the initial NaCl and NaF contents of the electrolyte were lost owing to volatilization and crucible penetration.

Jan 1, 1966

By S. A. Ferguson

Purpose: Marras et al. developed a technique to evaluate sincerity of effort during dynamic trunk motion performance. The validity and reliability of the technique have not been evaluated. Therefore, the objective of this study was to first determine whether or not a sincerity of effort measure correctly identified those giving a sincere effort in a blinded randomized control trial and second to quantify inter-rater and test-retest reliability. Methods: This article reports the findings of a two phase study. In phase one, the blinded evaluation, participants were randomly assigned to either a sincere or insincere performance condition. An examiner tested participants without knowledge of the participant&apos;s group membership. In the second phase, two examiners evaluated each participant twice to quantify inter-rater and test-retest reliability. Results: In the blinded phase the specificity was 100% and sensitivity was 90% for identifying sincere and insincere effort, respectively. Phase two results showed no significant difference in probability of sincere effort between raters or between testing sessions. Conclusion: A performance criterion that accurately identifies sincere vs insincere group membership during functional evaluations was identified. There were no significant differences between raters or between testing sessions. These findings indicate that this test is reliable and possesses good predictive validity in assessing sincerity of effort.

Jan 1, 2003

By E. R. Maize

This report is the third of a series on convergence of roof and floor in coal mines and subsidence of surface that accompanies it. The first papery dealt with extraction in a mechanized mine (Montour 10) having relatively short rib lines that retreat rapidly. The second 6/ dealt with extraction in a mine (Crucible) in which coal was loaded by hand and in which the rib lines were long and slow-moving. The present report deals with a mine (Gibson) in which conditions approximated those in the Crucible mine, except that the distance between room centers was considerably less and the pillars were narrower in consequence. Moreover, the average cover was less and the studies were made under the steep hillside of a stream valley compared with a gently rolling surface over the portions of the second mine studied. Gibson mine lies in the east-central part of Washington County, Pa., approximately midway between the Montour 10 and Crucible mines on a north-south line. A cooperative agreement covering the work was made with the Hillman Coal & Coke Co. through W. L. Affelder, vice president. This paper describes the methods used in the investigation, gives excerpts from the data obtained, and offers such generalisations as appear to be justified.

Jan 1, 1940

By Bill M. Stewart

Since 1974, a large amount of data has been developed concerning the physical properties and stability characteristics of waste generated by the mining and preparation of bituminous coal. However, very little information has been developed on the properties and characteristics of anthracite waste. During this Bureau of Mines research project, coarse anthracite breaker refuse from five sites in eastern Pennsylvania was sampled and the physical properties, which indicate stability characteristics, were determined in the laboratory. Coarse anthracite breaker refuse is quite similar to coarse bituminous refuse in chemical and mineralogical composition. However, the physical properties of the anthracite waste materials tested are different from those of coarse bituminous refuse. For the coarse anthracite breaker refuse tested, the average maximum laboratory density is 113.2 lb/ft3, the average angle of internal friction (direct shear) and average cohesion are 30.2° and 2.6 psi, respectively, and the average permeability (four sites) is 1.24 x 10-2 cm/sec. Stability analyses were conducted on six theoretical anthracite waste embankments. These analyses show the effects on minimum safety factors of geometry, phreatic surface level, and physical properties.

Jan 1, 1983

By O. Q. Leone

Excellent metal quality, with lower power requirement, is attained in electrorefining titanium by using internal heating of the fused-salt bath. An internal heater provides more effective heat utilization, simplifies structural components in cell design, and prolongs cell life by eliminating direct application of heat to the cell container. This Bureau of Mines report covers one phase of the research in progress at the Electrometallurgical Experiment Station at Boulder City, Nev., for improving the techniques and lowering the total power requirement for electro-refining titanium metal.

Jan 1, 1959