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By William J. Kemnitzer

This study was made to show the growth of petroleum coking and to determine trends and characteristics of marketing and utilization of coke on the West Coast, comparing these data with those of the United States as a whole. An earlier Bureau of Mines economic survey of petroleum coke was made in 1930 before the widespread use of coking processes. Data, derived from published and unpublished literature as well as from interviews with industry representatives, show a marked increase in the production of petroleum coke since the end of World War II. This increase resulted from the need of refiners to upgrade heavy residuums for which the demand was diminishing. Increasing coke production as well as significant market shifts away from California-produced coke have created excessive stocks of petroleum coke on the West Coast. The causes of these market shifts were based mainly on (1) economic factors and (2) certain undesirable qualities of some of the petroleum coke produced in California.

Jan 1, 1965

By Gordon Bath

During the summer of 1946, the Division of Geophysical Exploration of the U.S. Bureau of Mines established several primary magnetic base stations near important iron-producing districts in Minnesota, Michigan, and Wisconsin. Stations were located in groups of four to six in six separate base-station areas, and each position was marked with a concrete monument. Differences in magnetic intensity between stations in these areas, as well as the difference between each area and a magnetic datum at the magnetic observatory of the Coast and Geologic Survey at Cheltenham, Md., were measured with a modified Askania magnetometer. Measurements also were made with a Hotchkiss superdip to study the usefulness of the stations for the calibration of instruments of this type. The work was planned and supervised by F. W. Lee, chief of the Division of Geophysical Exploration, and Edward F. Fitzhugh, Jr., chief of the Minneapolis Division of the Bureau of Mines. Special mention is due Harold B. Ewoldt, Bureau of Mines engineer, for his assistance in the field work, especially in locating and establishing monuments. Special mention also is due Clyde L. Holmberg, of the Bureau of Mines, for the magnetic measurements made with the Hotchkiss superdip. Helpful suggestions were received in the field from H. L. James, of the U. S. Geological Survey. Acknowledgment is made of the cooperation of Stephen Royce, Irving E. Beckwith, Arthur Johnson, and Josiah Royce of Pickands, Mather & Co., and A. E. Matson, of Butler Bros. The U. S. Coast and Geodetic Survey furnished daily magnetograms from the Cheltenham Magnetic Observatory as well as calibration equipment and values of absolute magnetic intensity. Short-term forecasts of ionospheric conditions were obtained from the National Bureau of Standards.

Jan 1, 1951

By David D. Walker

The purpose of the investigation was to describe and appraise tungsten deposits in Montana . The work supplements previous investigations made by Pattee ( 10 ) and Walker ( 17 ) in selected areas of the State . Scheelite deposits in tactite are the most numerous and most important economically , having accounted for nearly all of the State's tungsten production . Of the 64 deposits examined during the current study , 50 contained scheelite , 11 hubnerite , 2 wolframite , and 1 ferberite . The State's major tungsten production has been from scheelite deposits in Beaverhead County . The report lists , by counties , the type and grade of each deposit . The more important occurrences are accompanied by geological and assay maps .

Jan 1, 1963

By H. B. Hill

The Salt Flat field, formerly called the Joe Bruner field, is located northeast of the town of Luling in Caldwell County, Tex. This field, which is a fault structure, approximately parallels and is about 5 miles east of the Old Luling field. The proved area is approximately 1,280 acres, on which 332 producing wells (September, 1930) have been drilled. The majority of the wells are producing from the Edwards limestone at an average total depth of 2,700 feet. A few wells are producing from the Austin chalk or from other formations above the Edwards limestone. The Wilcox formation is exposed, and the fault trace in places is scarcely evident. The strike of the structure is approximately N. 20 to 45° The displacement of the fault is probably 200 to 500 feet. The discovery well was completed in the Austin chalk by the Lutex Oil Co. during April, 1928. In October, 1926, the Sun Oil Co. completed the discovery well in the Edwards pay. This well was an important discovery, as it indicated the potential oil possibilities of the Edwards limestone in echelon fault structures. The discovery led to the development of the third fault field in the Edwards limestone and opened up a large area for future prospecting.

Jan 1, 1931

By O. C. Blade

This report on the properties of aviation gasolines and aviation jet fuels produced in the United States during 1955 was made under a co-operative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. Analytical data are presented for 116 samples of aviation gasoline and for 38 samples of aviation jet fuel. The analyses were made on samples typical of the manufacturers' 1955 production in their laboratories and the results submitted to the Bureau of Mines for compilation. The products of 20 manufacturers of aviation gasolines and of 16 producers of aviation jet fuels are represented.

Jan 1, 1956

For 11 years, under authorization of the Synthetic Liquid Fuels Act of April 5, 1944 (30 U.S.C. 321-325), and amendments, the Bureau of Mines has carried on an extensive research and development program to establish methods for producing oil from coal and from oil shale. This act was passed by the 78th Congress primarily because of the stress of wartime demands for liquid fuels to supply our armed forces during World War II. The act was progressively extended by the 80th and 81st Congresses, as later peace-time demand for oil and oil products continued to increase.

Jan 1, 1956

By G. W. Jones

In a previous report results were given and a method outlined whereby from a knowledge of the composition of the natural gas and of the inflammability limits of the individual constituents composing the natural gas, the limits of inflammability of natural gas and air mixtures could be closely calculated. This method is based on the application of Le Chatelier's law as modified by Coward, Carpenter and Payman, to apply to a mixture of any number of combustible gases. This law must not be used indiscriminately, because many exceptions have been found. For example, when ethylene, acetylene, hydrogen sulphide, or chlorinated hydrocarbons are present the law may not hold. For a discussion of the rally exceptions which have been found, reference should be made to a report by Coward and Jones. Before this method can be used the inflammable limits of the individual constituents must be known. Also, the composition of the complex combustible mixture, and representative mixtures besides, must be tested both experimentally and by calculation to prove whether Le Chatelier's law may be applied.

Jan 1, 1933

By Cecil Q. Cupps

Results are presented of a comprehensive study of the characteristics of the original oil in the Weber sandstone reservoir, Rangely oil field, Colorado. Through the medium of subsurface sampling, adequately representative samples of the original reservoir oil were obtained from many parts of the reservoir over a period of 5 years concurrent with active development of the reservoir. Data of differential gas liberation, pressure-viscosity, and. pressure-volume-temperature relationships are shown for 12 subsurface oil samples. Data also are given of reservoir pressure and. temperature, composition of liberated or solution Gas, composition of 22 produced-gas samples, and Hempel analyses of crude-oil samples from 18 wells. The characteristics or physical properties of the 12 subsurface oil samples, as determined by laboratory analyses, were correlated with elevation of the top of the Weber sandstone. These relationships of oil characteristics to elevation in the reservoir show that only the oil in contact with the initial gas cap was gas-saturated at the existing pressure and temperature. The characteristics of the original reservoir oil were marked by an appreciable decrease of saturation pressure and solution gas-oil ratio and increase of viscosity and density with depth below the gas-oil contact. The composition of solution gas and of' produced was also was found to vary with elevation of the oil in the reservoir.

Jan 1, 1951

By F. A. Penning

A number of highly instrumented free fall tests were performed on an arrestment system for a man cage in a vertical shaft. Tests were conducted in the U.S. Bureau of Mines free fall test tower at the Colorado School of Mines. A single tooth safety dog was used to stop on 4x6-in. Keruing (Phillipine mahogany) wet and dry wood guides. The safety dog had a penetration depth of 1 in., an adjustable width from 1-1/2 to 2-1/4 in., and a tooth angle of 80 deg. Twenty-seven free fall tests were performed covering a range in weights from 3-1/2 to 10-1/2 tons, hoisting velocities from 850 to 1350 feet per minute. Average g loads were measured from a low of 0.6 to a high of 3.4. The electronic instrumentation included piezoelectric and seismic mass accelerometers, strain gages on structural and mechanical elements, load cells in the guides, and distance measuring. Computer analysis was used to correlate with experimental measurements used to calculate stress. A statistical analysis gave no indication that the velocity or area affected the wood crushing stress. The instrumentation revealed a chatter occurring during the stop as shown by the accelerometers, strain gages, and load cells. Additional work is required to analyze this newly discovered phenomenon. The chatter imposes loads much higher than the average g load.

Jan 1, 1980

By Efrem R. Reeves

Noise-induced hearing loss (NIHL) is the most common occupational illness in the United States, with 30 million workers exposed to excessive noise levels [NIOSH 1996] every day. Of particular concern is the mining industry; which has the highest prevalence of hazardous noise exposure of any major industry sector [Tak et al. 2009] and is second only to the railroad industry in prevalence of work-ers reporting hearing difficulty [Tak and Calvert 2008]. This document is for operators, safety personnel, and mechanics in the mining industry who are not specialists in noise control engineering or acoustics. Evaluations of successful and unsuccessful attempts at controlling noise on several large, underground metal mining machines are detailed to illustrate the basic principles of noise control. Once personnel understand the guidelines and principles of noise control, they will be able to ¦evaluate the extent of a noise problem; ¦determine the best approach to the problem; and ¦apply the most appropriate solution. Because of the insidious nature of NIHL, it can go unnoticed until a considerable loss of hearing has occurred. In some cases, diagnosis is delayed because an exposed individual claims to have become accustomed to the noise. In reality, that person may have already suffered irreversible hearing loss. Humans can hear sounds in the frequency range from about 20 to 20,000 Hertz (Hz). Within this range, NIHL usually begins in the frequency region around 4,000?6,000 Hz, the upper levels of the speech region. The first noticeable symp-toms include difficulty understanding higher pitched voices, such as the voices of females and children, and difficulty understanding certain consonant sounds, which are primarily high frequency in nature. The extent of NIHL varies depending on the level and duration of noise exposure and on an individual?s susceptibility; despite having similar noise exposure, individuals can experience differing degrees of hearing loss, or none at all. NIHL is almost always preventable. To reduce or eliminate the possibility of NIHL, an individual?s noise environment must be analyzed and appropriate action taken to reduce noise exposure.

Dec 1, 2009

By E. Chin

The countries of Asia and the Pacific have large resources of diverse minerals. Australia and China have extensive mineralization that are commercially being exploited. The major minerals in Australia with known reserves adequate for both domestic demand and export markets include bauxite, clays, copper, diamond, gold, iron ore, lead, manganese, mineral sands (titanium minerals), nickel, salt, silver, tin, uranium, and zinc. China is the world leader in proven reserves of antimony, barite, magnesite, molybdenum, rare earths, titanium (ilmenite), tungsten, and vanadium. It also has about 55 billion tons of iron ore, albeit with an average grade of only 30 % to 35 % elemental iron content. With the exception of chromium and copper, China has significant resources of a wide array of minerals and metals, based on its production and/or export capability for these commodities. Additionally, India has significant resources of bauxite and mineral sands; Indonesia, bauxite, copper, nickel, and tin; Malaysia, tin and associated titanium; Mongolia, copper, fluorspar, and lead-zinc; New Caledonia, nickel; New Zealand, gold and iron sand; North Korea, magnesite; Papua New Guinea, copper, gold and mineral sands; Philippines, copper, chromite, and gold; and Sri Lanka, gemstones. Moreover, there appears to be extensive mineralization III Burma (Myanmar), Cambodia, Laos, Thailand, and Vietnam, but they have yet to be definitively delineated.

Jan 1, 1994

By Peter N. Gabby

A mineral purvey of 40,000 acres of the 42,213-acre Little Humboldt River Wilderness Study Area was conducted by the U.S. Bureau of Mines in 1985 at the request of the U.S. Bureau of Land Management. There are no identified mineral resources but anomalous gold, silver, mercury, and arsenic concentrations were found. The study area is located in Elko County, NV, in the Owyhee Upland geomorphic subprovince. It is underlain by mid- to late-Miocene-age rhyolite, basalt, tuff, vitric ash, and tuffaceous siltstone. On the south side and partly within the study area, a mining company recently (January 1986) located 125 contiguous claims over an area of hydrothermally-altered volcanic rocks that have anomalous surface concentrations of gold, mercury, arsenic, and silver. Anomalous gold-silver concentrations in altered rocks were encountered at several other widely scattered localities in the study area. These elevated metal concentrations and associated hydrothermal alteration indicate gold resources may be present in the study area. A 20-ft-thick bed of diatomaceous earth, which contains 60 to 85 percent diatoms, crops out 0.3 mi north of the study area. Elsewhere, three samples of altered volcanic tuff taken within the study area contain from 46 to 70 percent zeolite (clinoptilolite). The diatomaceous earth and zeolite sampled are not of sufficient quality to compete with materials presently being marketed. There has been no mineral production from the study area, but a caved adit, about 25 ft long, and six prospect pits were found.

Jan 1, 1987

Maps To Accompany Bulletin 418

Jan 1, 1941

By J. J. Hoeppner

Lignite samples were collected so as to be widely representative of the extensive deposits in the western north-central area. These were carbonized at temperatures ranging from 450° to 550° C., according, to a standardized procedure. In general, product yields varied; extremes obtained on selected samples show char recoveries on the moisture- and ash-free basis as 56.7 percent for slack lignite or "leonardite" to 80.8 percent for a concentrate of the fusain component from a typical face sample; normal lignite samples averaged approximately 70 percent. Tar-plus-light-oil yields ranged from 3.3 percent for the fusain concentrate to 11.0 percent for a normal sample, averaging approximately 8 percent; gas recoveries varied more widely both in yield and in composition, ranging, from 10.0 percent to 27.7 percent, the latter being from leonardite and quite high in carbon dioxide. Sampling was conducted with the view of representing, as nearly as possible, all beds delineated by Brant (2);4/ many are necessarily missing since collection was confined largely to worked deposits. Data presented in this report indicate a general uniformity of North-Central lignite in respect to low-temperature carbonization, with a few possible exceptions of a local nature. When processed according to the indicated conditions, maximum tar yield may be realized with minimum loss of recoverable heating value of the original coal. Natural weathering of lignite, however, does affect tar yield adversely and should be held to a practical minimum in any commercial operation.

Jan 1, 1956

By G. H. Keith

Oxygen and nitrogen cause strain aging in electrorefined vanadium, as evidenced by maxima in yield and tensile strengths and by Snoek internal friction peaks. Alloys containing up to 0.22 percent oxygen and 0.11 percent nitrogen were investigated. Tensile strengths of oxygen-and nitrogen-containing alloys were 66,000 and 68,000 psi at 300° to 400° C, compared with 53,000 and 62,000 psi, respectively, at room temperature. Total elongation decreases to about 7 percent at the temperature of maximum strength. At 600° C, strain aging is not evident. Based on interstitial contents calculated from internal friction measurement, the increases in strength caused by nitrogen and oxygen were 440,000 psi per weight-percent nitrogen and 260,000 psi per weight-percent oxygen. Application of the Schoeck and Seeger treatment to the Snoek effect in these systems results in a calculated lattice distortion of 0.24 and 0.15 caused by the presence of an interstitial nitrogen or oxygen atom, respectively. Alloys containing boron or carbon were also investigated. Both elements refine the grain size but have no other effect because of their low solubility in vanadium.

Jan 1, 1969

By K. R. Dorman

To develop the potential of precast concrete sets as a support medium in underground mines, a three-piece precast concrete drift set was designed for a small opening and tested to destruction in an underground straining frame. Thirty-six tests were made with three sizes of members using three different loading conditions. In addition, 14 members were tested individually in the laboratory. Test results are compared with theoretical calculations. A cost comparison shows the use of concrete sets would be advantageous where conventional wooden timber requires excessive replacement.

Jan 1, 1968

By Peter G. Chamberlain

The surge in gold and silver prices during the 1970's attracted many new mining operators and has rekindled interest among experienced ones. With its low capital investment requirements and fast payout, leaching has attracted many operators--particularly those with small or low- grade deposits. Although in certain situations leaching offers many advantages over conventional mining methods, many operators are uncertain how these relatively new techniques should be implemented. Consequently the Bureau of Mines has prepared this circular to disseminate information on gold and silver leaching practices, techniques, and problem. Engineering data gathered from 26 operations indicate that most ores are leached in heaps following crushing and distribution on pads. Metal values are recovered from cyanide leach solutions using either zinc precipitation or charcoal adsorption. Potential problems that my hamper on block development of a leaching operation are poor percolation characteristics of the ore, calcium salt buildup, low temperatures, and solution losses. An extensive bibliography on gold and silver leaching is appended.

Jan 1, 1984

Papers presented at a U.S. Bureau of Mines (USBM) technology transfer seminar describe the causes of violent material failure in U.S. mines, measurement techniques for monitoring events that result in violent failure, and mitigation techniques for controlling failure. Specific factors contributing to violent failure are identified on the basis of geotechnical monitoring in 16 U.S. hard-rock and coal mines and on statistical analyses of 172 coal bump events. New monitoring and analysis techniques developed as tools for assessing violent failure; geotomographic methods that provide new capabilities for the study of material failure and stress changes over large areas; and seismic methods for determining source locations, calculating energy release, and determining source mechanisms are described. Fair correlations have been established among seismic parameters, elastic stresses, face support load, and violent events. USBM studies have identified the advantages using both yielding and stable pillars for coal bump control. A computer program has been developed as an aid for selecting room-and-pillar layouts. The practical aspects of implementing a destressing program is outlined for coal mines, while the importance of mine orientation and timely support installation in controlling buckling-type failure is identified for hard-rock mines.

Jan 1, 1995

By I. F. Avery

The productive capacity of natural-gasoline and cycling plants in the United States on January 1, 1958, was 48.8 million gallons per day, according to the Bureau of Mines biennial survey. This represented an increase of 2.4 million gallons per day during the 2-year period since the last survey. In the previous 2-year period, capacity had increased 7.5 million gallons per day. The major increase in operating capacity occurred in Texas and New Mexico. In New Mexico, capacity increased 43 percent. The total number of plants decreased from 600 on January 1, 1956, to 584 on January 1, 1958. The number of operating plants decreased from 571 to 558. Five new plants were completed in Colorado, increasing the number of operating plants from 7 to 12.

Jan 1, 1958

By R. Clark Lantz, Charles Stanley, David E. Hinton

Morphometric examination of lung alterations following exposure to toxic and pathogenic substances is invaluable in detecting subtle changes which might otherwise be overlooked. Results, from evaluation of initial structural alterations, support and guide subsequent nonmorphological techniques and, when coupled appropriately, can lead to a better understanding of the pathogenesis of a disease. Morphometry is a technique which can be used to determine, quantitatively, the site, extent, development, and progression of a disease state. Determination of the extent of tissue and cellular involvement in the response to inhalation of silica has been performed in order to gain a better understanding of the development of fibrosis following inhalation of this toxicant. In addition, since silica has been postulated as one of the important pathogenic minerals in coal mine dust' it is important to understand the lung tissue response to silica prior to evaluating the effects of inhaled coal mine dusts. Male Syrian golden hamsters were placed in Hazelton 1000 inhalation chambers and were exposed to either filtered air (controls, n = 24) or filtered air plus 30 mg!m3 silica (Min-U-Si110,95%ofparticles < 5 um,n =24)for16hours per day, five days per week, for two weeks. Animals were returned to the animal quarters prior to subsequent tissue processing at 1, 4, and 12 weeks following exposure. This schedule was designed to allow time for the development of fibrosis. Lungs were fixed by intratracheal perfusion of ½ strength Karnovsky's fixative at a pressure of 20 cm H20 and tissues were taken for embedment and analysis at the light level. Determination of site, extent, and development of alterations was performed using a multitiered approach. Changes in large structures (airways, blood vessels) was determined prior to evaluation of changes at the septal tissue level. Data will be presented outlining the progression of changes. Results indicate the usefulness of morphometric analysis of lungs following inhalation of toxic substances in quantitatively defining the structural alterations.

Mar 1, 1989