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By J. W. Horne, W. B. Shirey

"INTRODUCTION The United States Bureau of Mines in cooperation with the State of Colorado at the University of Colorado has conducted experiments to determine the amount and composition of the noncondensable gases evolved when crude shale oil is distilled under pressure.Hydrogen sulphide is one of the components found in the complex mixture of gases produced by the distillation of shale oil under pressure. This paper deals with the apparatus and method used in determining the amount of hydrogen sulphide evolved in the laboratory experimental cracking stills.The study required a complete extraction of all the hydrogen sulphide from the gas stream after it left the water-cooled distillate condensers and before the as stream entered the charcoal absorber for removing the light naphtha. In devising the method it was necessary to take into account a constant variation of velocity, pressure, and percentage of sulphide in the total gas stream coming from the still.Ordinarily, the quantitative determination of hydrogen sulphide in Gas is made by analyzing small samples taken at regular intervals. This estimation can be accomplished by use of the Bunte gas burette as modified by Tutriler,4 or by a similar method. In the industries where the flow of as is constant end of uniform composition, this practice is sufficiently accurate for plant control. For experimental work where many variables have to be taken into consideration, as in the case at hand, these methods are not applicable."

Oct 1, 1931

By A. B. Cecala

The Bureau of Mines has developed a pallet loading dust control system designed to lower the dust exposure of workers during the bag stacking process at mineral processing facilities. The system makes bag stacking much easier because the pallet height remains constant throughout the entire bag stacking cycle through the use of a hydraulic lift table. The system uses a push-pull ventilation technique to capture the dust generated during bag stacking. A low-volume, high-velocity blower system operating at approximately 150 cfm blows a stream of air over the top layer of bags on the pallet. The blower system is composed of two 3-in air jets (approximately 1,200-ftjmin velocity) directed toward an exhaust system on the opposite side of the pallet. As these air jets travel across the pallet, they entrain the dust generated during bag stacking. The exhaust ventilation system pulls approximately 2,500 cfm of air and dust through the exhaust hood. This exhaust air can then be dumped into a baghouse ventilation system, or filtered before being discharged outside the mill. During a laboratory evaluation, a 70-pct dust reduction was recorded for the bag stacker. The system was then evaluated in an actual working environment. The first field evaluation was performed at a silica sand operation in which one worker performed the entire loading and bag stacking process. This worker's dust exposure was lowered 76 pet when using the new pallet loading system. The second field evaluation showed only moderate dust reduction, but this was mainly attributed to an overriding problem associated with background dust and the cleanliness of the bags. From both the ergonomic and production standpoint, the system was well received by both the workforce and plant management.

Jan 1, 1988

By L. B. Berger

Each winter brings its toll of deaths and serious accidents from the deadly gas, carbon monoxide. Newspapers carry warnings to the public of the dangers of this gas, and frequent now items retort the finding of persons dead or unconscious from the effects of carbon monoxide, yet these accidents continue. Either those warnings are not read, or they are unheeded by people who feel that "It can't happen to me." It can happen to you - carbon monoxide is no respecter of persons, as evidenced by items appearing daily in newspapers all over the country. Carbon monoxide has been a threat to human safety as long as man has used fire to keep himself warm and to cook his food. The burning of any fuel that contains carbon may produce carbon monoxide. This is true of solid fuels such as coal, coke, and wood; of liquid fuels such as oil, gasoline, and kerosene, and of gaseous fuels such as natural or manufactured gas. In the process of combustion the carbon in the fuel unites the chemically with tat oxygen of the air to form carbon dioxide (CO2), however, if the supply of air is not adequate, combustion is incomplete and carbon monoxide (CO) will be formed.

Jan 1, 1943

By G. L. Bloomsburg

This report describes work which was done to apply an existing finite element computer program UNSAT2 to the unsteady, unsaturated flow of water through waste shale piles. The work was done in three phases: 1. Verification of program through comparison with existing data. 2. Verification of program through simulation of flow from field seepage ponds at Rifle, Colorado. Considerable laboratory work was done in this phase to obtain capillary pressure-saturation-relative permeability data and hydraulic conductivity values for retorted shale. 3. Application of program to flow due to natural rainfall in a section through the Piceance Basin in Colorado, and a typical waste shale pile.

Jan 1, 1978

By Jerry J. Gray

Transportation charges for mineral commodity movements in western Oregon and western Washington were determined mainly by a stratified random sample canvass of producers. Total 1965 mineral production value for this area was $53.3 million; the cost or charge to move this production from the mine to the consumer or to the point of consumption was determined to be an additional $38.7 million. Thirty seven companies were contacted as a sample out of a total population of 349; the statistically expanded sample production value deviated 3.6 percent from that obtained by the Bureau's annual canvass. The agreement between the sample results and the canvass totals demonstrated the effectiveness of the sampling method for obtaining data with a predesigned level of accuracy. For comparison, the north-central Idaho and western Montana area was studied, A random sample experiment was designed, but because of the dominance of a few major companies, a random sample technique would have required more visits to producers than if only the larger firms were contacted. Eighty-four percent of the 1966 mineral value ($198.6 million) was accounted for by interviewing 27 firms out of a total population of 199. Total transportation costs or charges for the area were $26.7 million. The significant difference observed between the relationship of minerals production value and transport charges between the two areas investigated can be attributed to the difference in the minerals produced. The western Oregon and western Washington region is a nonmetals-producing area as opposed to the predominance of metals production in the Idaho-Montana region.

Jan 1, 1968

By K. O. Bennington

The thermodynamic properties of hedenbergite, of composition [(Ca0,9516) (Mg0,0583Fe2+0.7134 Fe3+0.0934 Mn0,1366) (Si206)], were experimentally determined at the Bureau of Mines. The standard enthalpy of formation determined by hydrofluoric acid solution calorimetry is AHf298 = -680.96±0.855 kcal/mol. The standard enthalpy of formation from the oxides is AR-96 = -24.55±0.485 kcal/mol. Low-temperature heat capacities were determined by adiabatic calorimetry from 12.3 to 300.1 K. The derived standard entropy is S-98 - 41.218±0.148 cal/mol-K. High-temperature heat capacities were measured with a differential scanning calorim¬eter from 397 to 1,147 K. These experimentally determined data were combined with data from the literature to calculate the Gibbs energies of formation and equilibrium constants of formation over the temperature range of measurements. Standard enthalpies of formation are given as a function of temperature. The standard Gibbs energy of formation at 298.15 K is AGf298 = -641.90±0.86 kcal/mol.

Jan 1, 1984

By Errol D. Sehnke

This U.S. Bureau of Mines report provides detailed information on worldwide bauxite production capacity by mine and country, including bauxite substitute materials in countries of the former Soviet Union, The information was compiled from a variety of domestic and international sources and was based on information available to the Bureau through December 31, 1994. Capacity data represent announced installed and planned capacities and do not necessarily reflect a U.S. Bureau of Mines judgment of actual mine operating levels or timing of planned expansions. The year-end capacity is the ?in place? capacity or estimated production capacity, whichever is larger.

Jan 1, 1994

"One of the functions of the United States Bureau of Mines is to investigate the ability of electrical mining equipment to operate in a gassy mine without danger of igniting explosive atmospheres. To accomplish this purpose, tests are made in which mixtures of gas and air are ignited in the equipment while it is surrounded by explosive atmospheres of the same composition. In such tests, records of pressures developed by the internal ex-plosions are obtained and observations are made of any flames, sparks, or smoke which may issue from bearings and joints. Occasionally the explosion pressures in a mining machine rheostat or a compartment of some other machine reach a value which is judged to be excessive or abnormal.A number of factors are known to influence the explosion pressures, and both German and. British investigators have irate extensive research on their effects. Much of this work had been done with artificial compartment which certain conditions could c held, constant while others were being varied. The U. S. Bureau of Mines has not made any research on a scale to compare with that of the British or German investigators; however, special studies have been necessary from time to time to determine the cause and remedy for high pressures obtained in the routine test of some piece of mining machinery. Thus it has been possible to verify some of tee theories established on a purely experimental oasis by practical tests of machines as actually built for mine use.Some of the factors determined the pressure that will result when an explosive mixture in a compartment or connected compartment is ignited are: (1) The volume of explosive mixture ignited, (2) the percentage of as in the mixture, (3) the amount of coal-dust in the compartment or compartments, (4) the degree of movement or turbulence of the mixture at the time of ignition, (6) tightness of the joints and bearings, (6) the size of opening between, compartments, (7) the distance between the point of ignition and openings, and (8) the cooling, effect of surfaces and of material inclosed in the compartments."

Dec 1, 1929

By R. H. Sprute

The Bureau of Mines conducted a feasibility study and designed an operational system for consolidating waste coal sludge in a 110-acre pond by applying direct current between buried and floating electrodes. Consolidation would reduce the sludge to half its present volume, there-by extending the working life of the pond as well as creating a safe, stable impoundment. The project was conducted by the Bureau under an agreement with the Washington Irrigation and Development Co. (WIDCO), located near Centralia, WA. Part 1 of this report, published as Report of Investigation 8666 in 1982, covers the results of laboratory tests at the Bureau's Spokane Research Center and of a small-scale field test at WIDeO's coal preparation plant. Test results show the process is efficient and cost-effective when power is applied at low current density. Part 2 (this paper) describes a detailed design for an electrokinetic system to dewater WIDCO's 110-acre pond with a 27.4-acre electrode array. Densification of the inactive sludge pond will require 3.6 yr of treatment for a total cost of $1,450,000. The study and design are site specific, but design procedures and analyses are sufficiently detailed to serve as a guide for applying the process to any sludge pond.

Jan 1, 1988

By C. H. Elder

A 5-hole pattern was drilled from the surface at a site near Oak Grove, Jefferson County, Ala., to degasify the gassy Mary Lee coal bed in advance of mining. Gas and water production was monitored for 1 year, 4 months to allow gas flow to stabilize fully. A thickened water stimulation treatment was designed and applied in one hole of the pattern to evaluate this degasification technique for the Mary Lee coalbed. A gas production rate of 70,000 fts/day after stimulation treatment indicates that the use of vertical boreholes coupled with hydraulic fracturing in advance of mining the Mary Lee coalbed would provide for more rapid degasification and could provide a possible source of natural gas.

Jan 1, 1974

By G. M. Molinda

The U.S. Bureau of Mines conducted an investigation to determine the nature and frequency of coal mine roof failure beneath valleys. A mechanism for this failure and suggestions for controlling this problem are presented. Hazardous roof conditions identified in some mines were positively correlated with mining activities beneath stream valleys. Mine maps with overlays of unstable roof and locations of stream valleys show that 52 pct of the instances of all unstable roof in the surveyed mines occurred directly beneath the bottom-most part of the valley. The survey also showed that broad, flat-bottomed valleys were more likely to be sites of hazardous roof than narrow-bottomed valleys. Evidence of valley stress relief was found beneath several valleys in the form of bedding plane faults and low-angle thrust faults. This type of failure, previously believed to be only a shallow phenomena, was found at mining depths as great as 300 ft. In situ, horizontal stress measurements beneath a valley and the adjacent hillsides, confirmed valley stress relief. Numerical analysis of 13 valleys overlying one mine property showed the effect of the valley excavation on horizontal and vertical stress.

Jan 1, 2010

By Robert C. Dyni

This report details the investigation of multiple-seam longwall subsidence conducted by the U.S. Bureau of Mines from 1978 to 1989. A field investigation monitored ground surface movements over four upper-seam longwall panels and six lower-seam panels. The characteristics of the subsidence occurring as a result of mining these panels are examined; in particular, the angle of draw, subsidence development, total magnitude and areal extent, and critical width are evaluated and discussed. Comparisons are also made between the characteristics of multiple-seam longwall subsidence and single-seam longwall subsidence that occurred at the same site.

Jan 1, 1991

By Paul W. McGann

THE MINERAL INDUSTRIES had a near-record year in 1950, as rising industrial activity in general, greatly accentuated by the outbreak of hostilities in Korea in midyear, called forth increasing supplies of mineral fuels and raw materials. The aggregate value of mineral production was second only to that in 1948, and the aggregate physical volume was exceeded only in 1948 and 1947. Lower coal production accounted for the failure to surpass these earlier years. Growth of production was fairly constant throughout the year, especially for crude petroleum; its physical output for the year as a whole exceeded that of 1949 by 7 percent. According to Federal Reserve Board indexes, other relative gains were 16 percent for coal, 9 percent for fuels in general, and 17 percent for metals. The increase for mining in general was of the order of 10 percent. This was not quite as large as the general increase in industrial production but clearly reflected the total-industrial trend (see fig. 1).

Jan 1, 1953

Major activities of the Bureau of Mines Explosives Research Center during fiscal year 1965 (July 1, 1964, to June 30, 1965) are reviewed briefly. Part 1 summarizes significant accomplishments of the projects that were active during the report period. Part 2 presents short abstracts of the publications that appeared in the Bureau series and in other media during fiscal year 1965. Publications issued after June 30, 1965 are noted where pertinent in footnotes but are not abstracted. ACKNOWLEDGMENTS The Bureau of Mines gratefully acknowledges the support given through cooperative agreements by the following organizations to investigations con¬ducted by the Explosives Research Center during fiscal year 1965: Dow Chemical Company Manufacturing Chemists' Association Monsanto Chemical Company The Sulphur Institute

Jan 1, 1966

By P. D. Tracy, M. W. Von Bernewitz

"IntroductionA study of 256 coal-mine explosions, which occurred during the period 1909-1924 killed 4113 men and injured 570 others, reveals the fact that there are the critical times of day when explosions are most likely to occur, and when corresponding care should be exercised to guard against disaster. Of these 256 explosions, 83 straight as explosions, 89 were straight coal-dust explosions, and 81 were mixed gas and dust explosions, while three were undetermined.It has been determined from the times given in these reports (in several cases no times were given,that the critical period in the morning ranges between 6 and 9 o'clock when 83 explosions took place with a peal. at 7;30 o'clock. Of these 55 were straight gas explosions, the remainder being either coal dust or mixed gas and coal dust explosions. The critical period in the afternoon or early ranges between 3 and 7 o'clock, when 113 explosions took place, with a peak at 6 o'clock. Of these, 87 wore straight coal-dust explosions the remainder being neither gas or mixed gas and coal-dust explosions. Between these morning and evening periods is one which might be called the noon period - that is, from 11m to 7. p. m. - when 26 explosions occurred while some of these were normal type of explosions - that is, as to causes - others were of unusual cause and character, and. are discussed later. A number of explosions (29 in all) took place during mid-afternoon, late at night, and early in the morning - that is, after midnight."

Sep 1, 1924

By V. E. Erwin, W. W. Adams

"Production of explosives for industrial use in,the United States during 1934 continued the upward trend begun in 1933 from the low-level output of 1932, and the output in 1934 was only slightly less than in 1931.Reports to the United Stated Bureau of Mines from companies engaged in the manufacture of industrial explosives showed that the quantity of explosives manufactured in the United States and sold during 1934 for use within the various States was 314,767,922 pounds - 23 percent more than in 1931.Production during 1934 included 39,207,845 pounds of permissible explosives 5 206,625,027 pounds of high explosives other than permissibles, and,68,935,050 pounds of black blasting powder of which 37,192,700 pounds were in granular form and 31,742,350 pounds in pellet form. These figures represent an increase over 1933 of 15.6 percent for permissible explosives, 30.9 percent for other high explosive, and 7.4 percent for black powder.Coal-mining operations were the chief consumers of permissible explosives; 99 percent of the total output in 1934 was used, in coal mines. The proportion used by bituminous mines was 59 percent and by anthracite mines 40 percent. Coal mining was likewise the principal consumer of black blasting powder, taking 88 percent of the total sales during 1934; of this proportion, bituminous mines received 78 percent and anthracite mines between 9 and 10 percent. Consumers of high explosives other than permissibles were more varied; the reports showed that 11 percent of the total quantity sold was for coal mining, 22 percent for metal mining, 17 percent for quarrying and nonmetallic-mineral mining, 46 percent for railway and other construction work, and 4 percent for all other purposes."

Oct 1, 1935

By Spencee L. Willett

In 1984, at the request of the Bureau of Land Management, the U.S. Bureau of Mines conducted mineral surveys of the 20,508-acre Blue Lakes (NV-020-600) and 5,142-acre Alder Creek (NV-020-600D) Wilderness Study Areas (WSAs) in northwestern Humboldt County, Nevada. The WSAs are part of an upthrown, north-south trending fault block associated with the Basin and Range province. Both areas are predominantly underlain by the Cretaceous Duffer Peak pluton which intrudes Triassic metasediments and Jurassic plutonic rocks to the east and Permian Happy Creek volcanics to the south. In the Alder Creek WSA and in the southwest portion of the Blue Lakes WSA, Duffer Peak granodiorite and Happy Creek volcanics are overlain by Tertiary basalt. No active mines exist within the Blue Lakes WSA; but, several prospects, claims, and mineralized outcrops are in the south and northeast portions. No mineral resources were identified but samples from discontinuous, vein-type deposits contained anomalous amounts of gold, silver, copper, lead, zinc, molybdenum, antimony, and uranium. Very fine, residual gold was detected in nine alluvial samples collected from a small deposit in the southwest corner of the WSA; average gold value was $3.58 per cubic yard (at $350/ounce). Two mines, several prospects, and mineralized outcrops adjacent to the Blue Lakes WSA contain mineralized, irregular structures which do not appear to extend into the Blue Lakes study area.

Jan 1, 1986

By Ludwig Schmidt

Steel tanks often corrode rapidly in oil fields where the gas produced with crude petroleum contains an appreciable quantity of hydrogen sulphide. In many instances working tanks have been discarded after only six months of service because of failure induced by corrosion. Aluminum has been used for some time in the fabrication of certain equipment incidental to the handling of oils containing hydrogen sulphide gas in solution, and has exhibited no serious corrosive action. These uses indicated that aluminum tanks might be equally effective in counteracting hydrogen sulphide corrosion. Consequently, in the spring of 1928, an all-aluminum stock tank of 500 barrels capacity and a "composite" tank of equal capacity, having a steel bottom and bottom ring and an aluminum top and top ring, were placed in service on the State-Lassiter lease of the Gulf Production Co. in Crane County, Tex. These tanks were under observation for one year, the test being sponsored by the Gulf Production Co., the Aluminum Co. of America, rind the Parkersburg Ric and Real Co. The results of this preliminary test sustained the belief that aluminum is highly resistant to hydrogen sulphide gas and likewise indicated the type or grade of aluminum which could be most economically used for lease tankage. However, in this preliminary test the Wake were not subjected to contact with the large quantities of highly concentrated brines such as often are associated and produced with crude oil. Therefore, it was suggested by representatives of .the Aluminum Co. that additional tests be made to include production conditions in which large quantities of brine would be handled, for past experience had shown that aluminum often is susceptible to the corrosive action of brines.

Jan 1, 1931

By Ludwig Schmidt

[Steel tanks often corrode rapidly in oil fields where the gas produced with crude petroleum contains an appreciable quantity of hydrogen sulphide. In many instances working tanks have been discarded after only six months of service because of failure induced by corrosion. Aluminum has been used for some time in the fabrication of certain equipment incidental to the handling of oils containing hydrogen sulphide L; as in solution, and has exhibited no serious corrosive action. These uses indicated that aluminum tanks might be equally effective in counteracting hydrogen sulphide corrosion. Consequently, in the spring of 1928, an all-aluminum stock tank of 500 carrels capacity and a "composite" tank of equal capacity, having a steel bottom and bottom ring and an aluminum top and top ring, were placed in service on the State-Lassiter lease of the Gulf Production Co. in Crane County, Tex. These tanks were under observation for one year, the test being sponsored by the Gulf Production Co., the Aluminum Co. of America, and the Parkersburg Rig and Real Co. The results of this preliminary test sustained the belief that aluminum is highly resistant to hydrogen sulphide gas and likewise indicated the type or grade of aluminum which could be most economically used for lease tankage. However, in this preliminary test the tanks were not subjected to contact with the large quantities of highly concentrated brines such as often are associated and produced with crude oil. Therefore, it was suggested by representatives of the Aluminum Co. that additional tests be made to include production conditions in which large quantities of brine would be handled, for pact experience had known that aluminum often is susceptible to the corrosive action of brines.]

Jan 1, 1931

By Michael S. Miller

In 1985, at the request of the Bureau of Land Management, the Bureau of Mines studied a 50,57U-acre portion of the 90,345-acre Twin Peaks Wilderness Study Area (CA-020-619A) in order to evaluate its identified resources. The area studied is located about 45 miles northeast of Susanville, CA, in Lassen County, CA, and Washoe County, NV. The area is underlain by Tertiary volcanic, volcaniclastic, and intrusive rocks. Quaternary stream, lake, and landslide deposits overlie the older rock. There are no mines or mining claims in the study area. One mineral resource, pozzolan, was identified. Mining claims, inactive in 1985, have been staked adjacent to or near the northwest corner of, and also southeast of, the study area. Examination and sampling of 17 mineralized sites, delineated mostly by prior geochemical surveys, showed at least 30 million tons of subeconomic pozzolan resources and small or low-grade occurrences of gold, silver, copper, lead, zinc, nickel, molybdenum, zeolites and clay.

Jan 1, 1986