Search Documents

By J. W. Horne, W. L. Finley, A. D. Bauer, D. W. Gould

"The Bureau of Mines and the State of Colorado are cooperating in an investigation of the oil shales of Colorado. in this report the yields and the results of analyses of the oil and, gas produced from a number of oil-shale samples from the principal deposits of Colorado and other oil-shale States, are compared with samples from Scotland and Australia, where the oil-shale industry has had its greatest commercial development, and also with a sample from Brazil *here extensive oil-shale deposits are found shale samples were not selected as being representative of the different deposits, but they illustrate the wide variation in the nature of the organic matter of different oil shales.A further study is being made of the chemical composition of the shale, distribution of nitrogen and sulphur. in the products, temperatures at which organic matter decomposes, and the results will be presented in subsequent Papers, With complete data available on the chemical composition of the shales, it may be possible to explain some of the differences in the nature of the products from the various shales,Most of the work described herein was done under the supervision of M. J. Gavin. L. C. Karrick, formerly of .the Boulder laboratory, assisted in the work and gave many valuable suggestions."

May 1, 1924

By Henry M. Harris, John E. Kelley, Thomas D. Roberts

A penetrometer apparatus for measuring viscosity of glass at temperatures up to 1,450 ° C was developed for use in establishing the viscosity coefficients required for high- temperature forming of ceramic materials . The major advantage of the method is that it can be used with samples of almost any shape or size without the necessity of forming or measuring shapes to close dimensional tolerances . Also , it has proved accurate in the range of 106 to 109 poises , a gap between the normal limits of other methods . The device , which operates on a single penetrometer principle , was used to determine the absolute viscosity coefficient of substances in centimeter - gram- second units of poises instead of relative penetration - rate units as with other penetrometers . Penetration of the viscous sample was sensed with a linear , variable differential transformer . The output of this transformer was recorded versus time , and the penetration rate was used in calculating the viscosity coefficient . The general equation relating penetration rate and viscosity coefficient was found to be 11 = F ( ln L/a 0.72 ) 2 π UL · where is the viscosity coefficient in poises , F is the penetrator load in dynes , L is the penetration depth in centimeters, a is the penetrator radius in centimeters and U is the penetration rate in centimeters per second . The penetrometer was tested using a standard viscosity sample of sodalime - silica glass obtained from the National Bureau of Standards ( NBS ) . Values obtained at several temperatures all agreed within 10 percent with comparable data calculated from the Fulcher equation derived by NBS for this glass . Equivalent accuracy was obtained with other glasses used to evaluate the apparatus .

Jan 1, 1964

The panic bars (and associated linkages and electrical circuitry) that are defined in this document are a machine operator-actuated control for the emergency deenergization of the tram motors on self-propelled, electric and diesel face equipment; including haulage equipment such as shuttle cars. There are nine basic types of panic bars (and several variations) that are recommended in this document, but all of the panic bars arc characteristically of the 'fire door" type that is frequently encountered on outside exit doors of many public, and some commercial buildings. It is also the intent of the following panic bar designs that, when emergency brakes arc added to the face equipment machinery for which they arty required, that they be designed and hooked up so that actuation of the panic bar will result in automatic application of the emergency brakes (immediately following the deenergization of the tram motors). The following panic bar design requirements are a restatement of the proposed requirements defined in the Federal Register, requirements cited in "Guidelines for the Design and Installation of Devices for Deenergization of Self-Propelled Electric Face Equipment/Automatic Emergency Brakes" by C. E. Lester and J. D. Greenhalgh of MESA, and Bendix recommendations that were formulated as a result of discussions with personnel at the various machine manufacturers and underground coal mines that we surveyed, discussions with G. I. Judy (our consultant), etc:

Jan 1, 1974

By M. Shabbir

A study was made to determine the optimum conditions for precipitation of uranium from mill solutions using hydrogen peroxide. Precipitation tests were made on both synthetic and actual mill solutions. Parameters studied included amount of hydrogen peroxide, initial pH, reaction pH, time, and temperature. Also investigated was the effect of varied amounts of vanadium, molybdenum, and sulfate in the test solution on uranium precipitation and product quality. The optimum conditions for complete precipitation and high product quality were (1) the use of 150 percent of the stoichiometric requirement of hydrogen peroxide, (2) initial pH of 1.0, (3) reaction pH between 3.4 and 5.0, (4) 4 hours reaction time, and (5) ambient reaction temperature. The excess hydrogen peroxide requirement is partially dependent on the amount of impurities present in the feed solution. The hydrogen peroxide process appeared applicable to treatment of the several mill eluate and strip solutions tested. The experimental studies also indicated that the hydrogen peroxide technique gives substantially better product quality than that produced by ammonia precipitation.

Jan 1, 1974

By James V. Luxner

The airflow and methane distribution patterns developed in an equipment-free entry 6.5 feet high and 12 feet wide, ventilated by line brattice operated blowing to or exhausting from the face, were determined by the Bureau of Mines for varying conditions. Results of these studies show that blowing line brattice systems of face ventilation are more effective than comparable exhaust systems. The face ventilating efficiency of any line brattice system is dependent upon the method of ventilation, the face distance, the tight rib distance, the volume of air delivered to the end of the line brattice, and the volume of methane released at the face. Experimental results indicate that maximum face ventilation efficiency is achieved when the inby terminus of the line brattice is installed 5 feet from the face and at a distance less than one-third the entry width from the nearest rib. Analyses of data are based upon the ability of a face ventilation system to dilute methane in the immediate face area.

Jan 1, 1969

To improve the level of hearing protection by providing workers with an inexpensive, easy-to-use device to check earplug fit. Background Approximately 30 million workers are exposed to hazardous noise on the job, placing them at risk of permanent hearing loss, tinnitus, and other disorders. Although the preferred solution is to eliminate noise through engineering controls or to reduce noise exposure through administrative controls, hearing protectors are critical when noise is unavoidable. Studies of hearing protector users have shown that average protection values in the real world are much lower than the labeled noise reduction ratings determined in laboratories with trained and motivated subjects. Even worse, many hearing pro­tector users get virtually no protection at all because of poor fit. The studies also show that users have a harder time achieving adequate protection levels with earplugs than with earmuffs. It?s difficult for users to tell if earplugs are working well just by looking at them. A more accurate approach is to check how much they block or ?attenuate? noise. Earplugs vary in their attenuation characteristics, with most providing a maximum of 20?35 decibels of noise reduction when worn correctly. Any earplug that?s suitable for use in noisy settings will attenuate noise by at least 15 decibels. Personal fit testing is an effective way to help hearing protector users improve the fit and protection levels of the devices. However, existing fit-testing systems are expensive and unsuitable for use at many industrial worksites.

Dec 1, 2008

By Harry Freund

Gallic acid is a sensitive, stable, colorimetric reagent for the determination of tantalum in the range of 2 to 40 µg.Ta/ml. The method consists of the fusion of tantalum oxide with potassium pyrosulfate and solution of the cooled melt in satu-rated ammonium oxalate, followed by development of a yellow complex with an ethanolic solution of gallic acid. The tantalum-gallic acid complex absorbs over a broad region in the blue and near ultraviolet. Adverse effects due to interfering ions and solution conditions, such as oxalate concentration and pH, can be minimized by a suitable choice of wave length. A new and sensitive colorimetric method is provided that has been used successfully at the Northwest Electrodevelopment Laboratory of the Federal Bureau of Mines for determining minor amounts of tantalum.

Jan 1, 1956

Aid mine operators as well as mine inspectors in making quick but sufficiently accurate measurements of the rock dust content of coal/rock dust mixtures. The Problem Past research has shown that accumulations of volatile coal dust in underground coal mines can be rendered non-explosive by dilution with chemically inert rock dust (usually limestone). Consequently, rock dusting is required by law in U.S. underground coal mines. However, mine officials and inspectors have no quick and reliable means to determine whether enough rock dust has been applied to achieve a mixture that is in compliance with the law. Even the compliance tests used by the Mine Safety and Health Administration (MSHA) are slow and involved. MSHA assures that a mine has been rock dusted adequately by collecting samples from rock dusted areas of the mine and sending the samples to a laboratory for analyses of the inert-dust content. The analyses may not be completed for more than two weeks, during which time the mine in question might be inadequately protected against coal dust explosions. To solve this problem, the Bureau of Mines devised a quick, simple and reliable device that can immediately determine the rock-dust content of a mixture of coal and rock dust.

Jan 1, 1985

By Earl W. Waay

"Since the beginning of the petroleum industry in 1839, up to within two or three years ago, these has been a dearch of engineers who have had the fundamental technical training also sufficient practical experience so that they could compete with practical men. Need for Technical Investigations in Industry: As in the early stages of the mining industry, the petroleum industry has been rather slow in realizing the need for technical assistance and investigators in the development and production of oil lands. The rapid increase in consumption, however, during the past few years has accentuated this need more than anything else could have done. When it is realized that our production cannot longer keep pace with the demand, it is easily understood why it is imperative that be instituted which will tend to conserve and prolong the supply of oil from the fields now known. It is interesting to note from preliminary production figure given cut by the U. S. Geological Survey, for the year 1919, that the United States produced about 430,000,000 barrels, an increase of 22,000,000 or 6 per cent over 1918 production and also there was imported, chiefly from Mexico, a little over 52,000,000 barrels, making a total of 430,000,000 barrels, to satisfy the trade demand in the United States of which almost 6,000,000 barrels was exported. Stocks were not materially increased.Other significant facts regarding our petroleum industry, are that just recently the U. S. Shipping Board in soliciting bids for 24,000,000 barrels of fad oil to meet prospective needs, received bids for only 1,500,000 barrels at prizes ranging from 75 to 90 per cent higher than was paid last year. One large company on the Pacific Coast has stopped its export trade, and has notified consumers,of gas-engine distillate that they will no longer make deliveries of this product. This will materially affect the farmer, in many instances, through his use of the truck and tractor."

Apr 1, 1920

By Andrew B. Cecala

As deeper seams are continually mined, methane liberation will continue to increase and must be monitored effectively. To effectively monitor and develop appropriate control technology, methane-liberation patterns must be known. The Bureau of Mines recently completed a study to identify specific patterns of face methane liberation during long- wall mining. Both of the longwall faces surveyed had high methane liberation rates. At one longwall face, most of the methane was liberated during cutting of coal by the shearer mining machine. At the second face, a significant portion of methane was emitted from the face and floor. An effective methane-monitoring system would be different for each longwall panel because of the differences in how the gas is released along the face.

Jan 1, 1985

By Joseph A. DeCarlo

The annual survey of the oven-coke industry by the Bureau of Mines, United States Department of the Interior, described in this report shows that 79 plants were operating in 22 States December 31, 1956. On that date 15,923 serviceable ovens existed, with a maximum total annual coke capacity of 79,965,100 net tons, and 631 new ovens were under construction. Their annual coke capacity was 3,307,300 net tons. The number of serviceable ovens in existence relates only to those capable of producing coke and does not include (1) any ovens that were blanked off or retired permanently in batteries that were operating December 31, 1956, and (2) ovens that had been demolished and were being rebuilt on that date. For this reason, the number of ovens at furnace plants reported by the Bureau of Mines at the end of each calendar year differs from the number reported for the same group by the American Iron & Steel Institute, as the institute includes ovens being rebuilt.

Jan 1, 1958

By M. J. Ferrante

Relative enthalpies of high-purity disodium hexatitanate (Na2Ti6013) were measured at the Bureau of Mines to provide new thermodynamic data needed to advance the technology of materials. Measurements from 298.15 to 1,478 K were made by drop calorimetry with a copper block. Tabulated values are listed for the standard relative enthalpy, heat capacity, en-tropy, and Gibbs energy function between 298.15 and 1,500 K. Enthalpy data are also given in equation form and are combined with thermodynamic data from the literature to derive values of standard enthalpies of formation, Gibbs energies of formation, and logarithms of the equilibrium constants of formation. Similar calculations were made for the reaction of Na20 with Ti02.

Jan 1, 1986

By Warren E. Morrison

Demand for energy in the United States in 1965 was stimulated by the continuing expansion of the economy. A gain of 5.9 percent in gross national product for the year was accompanied by a 4.4-percent rise in energy consumption. Domestic energy resources met about 93 percent of the nation's requirements. The remaining 7 percent consisted of imported fuels, mainly of crude petroleum and residual fuel oil. The major fossil fuels-natural gas, crude petroleum, and coal, in that order-contributed 96 percent of all commerical energy utilized, with the balance of 4 percent being primary electricity from hydropower and nuclear power plants. Production was up for all of the major mineral energy resources in 1965, with the single exception of anthracite, output of which continued to decline. Bituminous coal output for the year was 512 million tons; marketed production of natural gas, 16,039 billion cubic feet; and crude petroleum output, 2,848 million barrels. Among the secondary products processed from primary energy resources, the most significant gains were in coal carbonized for coke which increased 6.7 percent to 95 million tons, and in the output of liquefied gases from natural gas which rose 4.8 percent to 11,257 million gallons (268 million barrels). Within the latter category, the off? take for petrochemical feedstocks continued to rise at a very rapid pace.

Jan 1, 1967

By K. C. Dean

A flotation method was developed by the Bureau of Mines for concentrating pollucite, a cesium-aluminum-silicate mineral that may contain from 20 to 40 percent cesium oxide. Separation of the pollucite from three typical ores was achieved by froth flotation of the associated micas, feldspars, and other gangue minerals, using sulfuric and hydrofluoric acids and a cationic-type collector. A low-tenor, 8 percent cesium ore from Maine was upgraded to 20 percent cesium with recovery of 87 percent of the cesium. Relatively high- grade ores from Canada and Southern Rhodesia were beneficiated at lower ratios of concentration to 28 and 29 percent cesium content respectively with recovery of over 92 percent of the cesium. In addition to concentrating the cesium content of ores, the method also effectively separates cesium from sodium, potassium, and lithium, and in certain ores from rubidium. This is accomplished by selective froth flotation of the alkali metal-bearing gangue minerals such as lepidolite, other micas, and feldspars. Since the alkali metals, especially potassium and rubidium, are difficult to separate chemically or thermally from cesium to prepare high- purity cesium products, separation by physical mans is important.

Jan 1, 1962

By Eugene T. Sheridan

The 25th annual survey of the peat industry by the Bureau of Mines, United States Department of the Interior, disclosed that 79 companies produced and sold peat from 81 operations in 21 States in 1958. Peat is a carbonaceous deposit, formed under water or in a water-saturated environment from plant material. It is the first stage in the development of coal and, when properly dried, can be used as fuel. Although 98 percent (estimated) of the total world production is used for energy purposes, the status of peat in the United States is somewhat unique in that none is used for fuel, and practically all is consumed as an agricultural product, chiefly for soil improvement purposes. The domestic peat industry has expanded rapidly since World War II, and production in 1958 was 327,813 net tons valued at $3,445,767. More than one-half million ton of peat was consumed in the United State in 1958, however, as 269,096 tons was imported.

Jan 1, 1959

By A. L. Engel

In the period of 1942-1945, medium-grade, oxidized, lead-silver ore was mined and shipped from the Diamond district near Eureka, Nev. An encouraging tonnage of low-grade ore was developed during these operations and partly blocked-out for future mining. If the low-grade ore could be treated profitably, further development of the district would result, and production of an important strategic metal might be increased. A representative sample of Diamond district ore was obtained through the Reno office of the Mining Division for the studies described in this report. The sample consisted of lumps and fines of a highly altered siliceous rock containing much earthy red hematite and some granular black hematite. Examination with the binocular microscope showed the lead carbonate mineral, cerussite, in seams and disseminated in the hematite. No zinc or silver minerals were identified, and no sulfide minerals were present. Analyses of the ore showed:

Jan 1, 1951

By J. A. Eisele

The Federal Bureau of Mines is engaged in a continuing program on the recovery of alumina from domestic source materials. Of the six processes being studied, current efforts focus on HCl leach of clays. A key step in the HCI process is the removal of iron from the aluminum chloride leach liquor. This was accomplished .by solvent extracting the iron with a tertiary amine in kerosine to which decanol was added as a phase modifier. In a mixer-settler operation, iron in the raffinate was reduced to <10 ppm in two extraction stages from a feed containing 1.4 gil Fe. Iron was stripped from the organic phase in three stages with dilute HCl.

Jan 1, 1976

By Raymond M. Stateham

Climatic conditions are compared with roof fall occurrence from April 1, 1972, to December 31, 1975, by the Bureau of Mines. These comparisons indicate that humidity has a strong influence on roof fall occurrence rates. Cubic regression techniques are used to develop best fit curves. Statistical analysis of these curves indicate that both are sinusoidal and exhibit positive correlation with each other. The sine waves have a period of 1 year with maximum and minimum inflection points in August and February.

Jan 1, 1978

By C. A. Komar

Renewed interest in the underground gasification of coal evolves from comprehensive studies of earth fracture systems that indicate that the movement of fluids can be controlled in the coalbed. In particular, directional property studies of natural microfissure occurrence, permeability, ultrasonic velocity, tensile strength, and orientation of intervals of inherent rock weakness, together with geologic structure setting and fracture trace analysis, can predict the gaseous flow paths in the coalbed. Having this information, the dominant direction in which gases generated and/or liberated by heat would move can be determined so that appropriate well patterns can be developed. Together with advances made in drilling technology that permit long horizontal holes to be drilled through the coal seams, tests can be conducted to determine whether directional control will permit devolatilization of the coalbed and gasification of the remaining hot coke in a systematic manner to produce a low-Btu gas suited for the generation of electricity.

Jan 1, 1973

By C. L. Klingman

The Bureau of Mines tested eight commercially available, activated charcoals experimentally to compare the following characteristics: capacity for adsorption of nitrogen at 77° K and 170 atmospheres&apos; pressure, surface area, carbon tetrachloride adsorption capacity, hardness, and density. The nitrogen adsorption test was devised to simulate plant conditions occurring in the final step of purification in Bureau helium faciliti.es. The remaining tests were patterned after empirical acceptance tests that are widely used throughout the adsorbent industry. Surface area and carbon tetrachloride adsorption correlated well with nitrogen adsorption. The samples with low density generally had better adsorption qualities than those of higher density. The carbon tetrachloride test appeared to be the most practical for selecting a charcoal to be purchased, but an attrition, or hardness test should also be run to be sure the charcoal will not crumble in use.

Jan 1, 1966