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By G. F. Friel

A series of experiments in the U.S. Bureau of Mines Safety Research Coal Mine at the Pittsburgh Research Center evaluated the effects of crosscuts on the travel time of carbon monoxide (CO) along an entry to improve the accuracy of a mine-fire locator program. Three entries, ten single crosscuts, and three double crosscuts were instrumented with CO sensors. One-percent CO in nitrogen was released and monitored as it traveled the entries. In addition to dispersion of CO at the front of the CO wave, CO was entrained from the entry into the crosscuts. It was determined for an entry and single-crosscut configuration that the measured travel time for a concentration change of 5 ppm was 27% greater than the predicted time based upon entry volume only, but 13% less than the predicted time based upon entry and crosscut volumes. For an entry and double-crosscut configuration, the measured travel time for the same concentration change was 25% greater than the predicted time based upon entry volume only, but 10% less than the predicted time based upon entry and crosscut volumes. An effective dispersion coefficient for CO dispersion along one of the entries was estimated to be 1.5 m2/ s.

Jan 1, 2010

By Lindsay D. Norman

Computer models for simulating the construction and for calculating the properties of particulate solids in two- and three-dimensional systems (coverings of circles and packings of spheres, respectively) were developed. By simulating the physical process of constructing circle coverings and sphere packings, in which the circles or spheres were randomly selected from many different distributions of sizes, physically realizable loose random assemblies were simulated whose physical and geometrical properties were predictable with the computer. Many of these properties, such as the number of contacts, are extremely-difficult to measure accurately, or considerable ingenuity is required in their determination. All of these properties were easily and accurately calculated by the computer models for many different coverings and packings constructed from equal, discrete, uniform, and log-normal distributions of particles. In addition to the loose random assemblies, dense random covering and packing constructions were simulated whose properties are ideal upper limits for those of the loose random coverings and packings. The properties of the dense random coverings and packings, heretofore only obtainable by theoretical analysis, were also simply obtained. The statistical geometry of loose random coverings and packings was studied, and several new interpretations of the area-covering or space-filling requirements in these systems were made. In two dimensions, it was found that the properties of all loose random coverings are predictable by taking suitably weighted averages of the corresponding properties of just four kinds of polygons whose edges are defined by connecting the centers of mutually tangent circles in the covering. The distributions of these polygons that permit area-covering were determined, and empirical equations for predicting the density, average coordination number, and average pore area in loose and dense random coverings were formulated. The properties of loose packings were determined by performing a simplicial division of the computer-simulated assemblies to produce a unique set of minimum volume, space-filling tetrahedra whose edges connected the sphere centers in each packing. A simple empirical equation was formulated that permits the calculation of the average number of contacts in any sphere packing, random or regular. Some of the statistical geometrical properties of the simplicial tetrahedra in the computer-simulated packings were analyzed. The tetrahedron edge length distributions in all the loose random packings were nearly identical when the edges were presented in terms of sphere diameters, regardless of the sphere population in the packing. Moreover, the gap lengths in the loose packings were to an excellent approximation representable by a uniform distribution of sizes. The distributions of spheres in tetrahedra resulting from the simplicial division of the loose random packings also existed in the tetrahedra in dense random packings. These observations were employed in developing a unique method for predicting the geometrical properties of loose random packings without simulating the assembled packing. Instead, the space-filling simplicial graph could be predicted for any given density of packing of any sphere population. The cumulative packing properties of these tetrahedra were shown to be nearly identical to those calculated by all loose random packing simulations attempted in this investigation. The simplicial tetrahedra completely describe a packing and can therefore be used to predict all properties of interest.

Jan 1, 1971

By Galen H. Clevenger, MARTINUS H. CARON

Although there are exceptions, oxidized silver ores containing the higher oxides of manganese are generally refractory to hydrometallurgical methods of treatment. When these ores are of high enough grade they can be smelted; indeed, some rather low-grade ores of this type have been smelted at a profit because of their fluxing value. In the past, when these ores could not be smelted, they either were not treated or were treated at low efficiency, generally by cyanidation. The need for thorough investigation of the problem was therefore evident for some time before the writers began their research. The problem of treating manganese-silver ores seems to have been recognized first about 35 years ago by C. W. Goodale in applying pan amalgamation at Tombstone, Ariz. He attributed the low extraction of silver to the fouling of the mercury by manganese rather than to the presence of a refractory compound of manganese and·silver. Although definite knowledge as to the cause of the poor extraction of silver was lacking, a more or less effective preliminary treatment, that is, a chloridizing roast, was applied. E. M. Hamilton, in 1909, was perhaps the first to define clearly the problem as it affects the cyanidation of silver ores and to suggest possible methods of preliminary treatment. Most of the work done in the interval between the appearance of Hamilton's paper and the assumption of the investigation by the authors was in the nature of routine tests covering suggestions already made rather than of research directed to a fundamental study of the problem. No practical application has so far been made of any of these proposed processes. The investigation described in this bulletin has proved that there s a refractory compound of manganese and silver-probably a manganite- insoluble in cyanide solution and other common solvents for silver. Although this compound has not been isolated from natural ores, it has been made synthetically, and shows all the characteristics of the natural product. Furthermore the authors have shown definitely that heating in air a relatively small amount of a silver compound with a large excess of silica (in the proportions ordinarily occurring in a commercial silver ore) renders

Jan 1, 1925

By A. C. Smith

The U.S. Bureau of Mines conducted a study to evaluate the effect of underground mining conditions on the activation of automatic sprinkler heads. Sprinklers were exposed to liquid fuel fires in a rectangular tunnel at airflows of 0, 45, 90, 150, and 250 m/min to determine the effect of ventilation and fire size on the time to activation. As the airflows were increased, the time to activate the sprinklers for a given fire size increased. Also, as the fire size increased, the activation time decreased. Temperature profiles of the tunnel showed that the maximum temperature near the roof was shifted downstream as the airflow increased. Experiments to determine the effect of rated activation temperature and response time index (RTI) value on activation time showed that the time to activate increased with increasing activation temperature, and decreased with decreasing RTI value. Exposure to the mine environment showed little effect on the activation times in large-scale experiments, and no significant effect in laboratory experiments. The results showed that airflow can have a significant effect on the activation times of automatic sprinklers. This needs to be considered in the design of effective sprinkler suppression systems for ventilated areas.

Jan 1, 2010

By C. P. Mishra

The Bureau of Mines performed a study of the availability of cobalt from market economy countries. The study entailed the detailed analysis of 97 deposits which contain 3.9 billion lb of cobalt at the demonstrated level; in 94 of the deposits cobalt is recovered as a byproduct, and in 3 it is considered the primary product. Since 97 pet of all recoverable cobalt is derived as a byproduct from copper and nickel deposits, the report focused on these two sources. At an assumed market price of $0.89flb for copper, $3.45/lb for nickel, $475/tr 021 for platinum, and $7/lb for cobalt, 1,330 million lb of cobalt at the demonstrated level are potentially available. This total includes 1,105 million lb of cobalt from copper properties, 190 million lb from nickel, 29 million lb from platinum, and 6 million lb from primary cobalt. This analysis indicates that the production cost for 589 million lb of cobalt can be totally covered by the revenues obtained from the other metals produced. The impacts of increases in capital investment and energy costs are also discussed.

Jan 1, 1985

By W. O. Vanderburg

The leasing or tribute system has been an important factor in the development of our metal-mining industry, particularly in the gold and silver mines of the Western States. It has received its widest application in. the early history of many camps and in the last stages of many mines. The system is especially adapted to mining where the ore's occur in narrow veins or are erratically distributed in small bunches or pockets so that selective mining, hand sorting, screening, or hand cobbing is required to produce shipping or milling-grade ore. The leasing system is also applicable to the development of prospects where the owners are unable or unwilling to assume the risks of searching for ore. The virtue of the system lies in the opportunity it affords miners with little capital to get started; at the same time, it rives owners an opportunity to have their property developed at small cost.

Jan 1, 1934

By J. L. Eakin, J. P. Powell

"The increased costs of exploration and drilling of new oil fields and the continued success of water flooding in nearly depleted oil fields have created a demand for information on the results obtained from individual projects. The Bureau of Mines has published several reports concerning water-flood activity in the Midcontinent area and at the request of the industry has continued to collect and disseminate this information. This report was written in response to these requests. It describes in detail the water-flooding projects in Anderson, Franklin, Linn, and Miami Counties, Kans., and includes methods of water treating and the results obtained. The production histories of each county and many water-flood projects are shown graphically from the date of the first development. Maps of most of the major projects, showing their status as of January 1, 1953 are presented also.The practice of injecting water to stimulate oil production was legalized in Kansas in 1935, and the first water-flooding project authorized in this four-county area was initiated by the Texas Co. in December 1935 in Linn County. Forty-nine projects2/ initiated in the area to January 1953 are estimated to have recovered approximately 10 million barrels of oil that would not have been produced by methods used previously. About 7,900 productive acres had been, or are, flooded by these projects, and approximately 136 million barrels of water had been injected.These four counties in the eastern Kansas shallow production area3/ were an important factor in the early history of the Kansas oil and gas industry. This position has been maintained from the very beginning through the early period of vacuum and air injection and into the era of water flooding. The location of the area and the relative position of the four counties and water-flooding areas in each are shown in figure 1.The first drilling for oil in this area in 1860 resulted from investigations of the existence, and use by the Indians, of so-called tar or oil springs. The first wells drilled were nonproductive, and the impending Civil War caused the search for oil to be discontinued. In 1884 a few shallow oil wells were drilled near Paola, and completion of several gas wells near that city led to subsequent drilling of an oil well, which was completed in June 1885, having an initial flow of 10 barrels of oil daily.In 1904 the original Paola gas field became a good oil-producing field. In 1905 the Rantoul field in Franklin and Miami Counties was opened; and drilling activity spread throughout the adjoining area, resulting in development of several shallow oil pools in Linn and Anderson Counties. The first ""shoestring"" pool in eastern Kansas to produce oil was probably the Paola or Pressonville shoestring, which was discovered in 1917. The rate of oil production from the area declined until 1919, when the Centerville shoestring pool was discovered. Discovery of the Colony gas field in 1921 was followed within a few months by drilling of the Garnett and Garnett and bush City shoestring pools. The Schermerhorn pool (now part of the Centerville field) s discovered in 1927, and the Kincaid shoestring pool was first drilled in 1931. The oil-production histories of the individual counties are discussed separately."

Jun 1, 1953

By W. E. Robinson

Oil-shale kerogen was processed into oil and oil products before the first oil well was completed by Drake in 1859. However, because of economic and other advantages, natural petroleum has been the principal source of liquid fuels and lubricants since 1859 and is a convenient root of many [organic] chemicals in common use today. In recent years the difference has narrowed between the cost of producing liquid fuels from well petroleum and other sources. This narrowing of cost difference has resulted both from the increased cost of finding new sources of petroleum in the United States and the experimental demonstration of lowered costs for synthetic liquid fuels by the Federal Bureau of Mines and by industry. Available petroleum resources of this country are being reduced and eventually may be inadequate to meet the demand. Alternate means of assuring an adequate supply of liquid fuels for this country include the development of processes for utilizing other carbonaceous materials such as oil shale and coal.

Jan 1, 1960

By Ernest W. Loya

The Bureau of Mines has developed a computer program for calculating the composition of gravimetric primary standard gas mixtures. The Fortran IV program applies corrections due to buoyancy variations of the cylinder and inaccuracies of the balance weights. The program also determines the statistical error due to the sensitivity and precision of the balance and applies the analytical error of the weighed gases.

Jan 1, 1985

By B. J. CROSS., Henry Kreisinger, John Blizard, C. E. Augustine

This bulletin presents the results of 36 tests made on a 468-horsepower Edge Moor boiler fired with pulverized coal at the Oneida Street Station of the Milwaukee Electric Railway & Light Co., Milwaukee, Wis. The tests were made by the fuel section of the United States Bureau of Mines in cooperation with the research department of the Combustion Engineering Corporation. Illinois coal was used as fuel; the furnace, burners, and feeders were designed by the Locomotive Pulverized Fuel Co. The object of the tests was to determine what over-all boiler efficiency could he obtained with pulverized coal under various conditions of furnace operation and with coal of different fineness and moisture content. The investigation was thorough. The pulverized coal, as it was supplied to the furnace, was weighed in specially designed tanks placed on platform scales. Twenty-nine of the tests were of 24 hours duration, three of 16 to 18 hours, and four of 12 hours. All tests are reported excepting two-8 and 20-which had to be stopped abruptly, No.8 because a motor actuating the coal-feed screw burned out and No. 20 because of trouble with the feed pump. Tests 1 to 27, inclusive, were made with round burners and tests 28 to 3Rwith spreading burners. In the first nine tests a large excess of air was supplied in an effort to prevent the ash fusing at the bottom of the furnace. In tests 10 to 16 the supply of excess air was reduced in order to get a high efficiency, regardless of the slagging of ash at the furnace bottom. Tests 17 to 27 were made with a water screen about 10 inches above the bottom of the furnace, to make possible the burning of coal with a small supply of excess air without the ash fusing at the bottom of the furnace. Tests 28,29, and 30 were made without the water screen and with a small supply of excess air, and tests 31 to 38 with a water screen around the walls near the bottom of the furnace. Tests 32, 33, 34, and 35 were run with coarser coal than that used ordinarily at the plant. Tests 36,37, and 38 were made with undried coal.

Jan 1, 1923

By Ralph H. Espach

In the spring of 1943, when it was evident that the Tensleep sandstone in the Elk Basin field, Wyoming and Montana, held a large reserve of petroleum, Bureau of Mines engineers obtained samples of oil from the bottom of nine wells and analyzed them for such physical characteristics as the volumes of gas in solution, saturation pressures or bubble points, shrinkage in volume caused by the release of gas from solution, expansion of the oil with decrease in pressure, and other related properties. The composition of the gas in solution in the oil was studied. The pressures and temperatures existing in the reservoir and the productivity characteristics of the oil wells were determined. The data obtained indicate that the oil in the Tensleep reservoir of the Elk Basin field has unusually varying physical characteristics, such as a saturation pressure of 1,250 pounds per square inch absolute and 490 cubic feet of gas in solution in a barrel of oil at the crest of the structure, and a saturation pressure of 530 pounds per square inch absolute and 134 cubic feet of gas in solution in a barrel of oil low on the flanks. The hydrogen sulfide content of the 6a r; in solution in the oil varies from 18 percent for oil on the crest to 5 percent for oil low on the flanks of the structure. Of even greater significance is the fact that these and other variable characteristics of the reservoir oil are related to the position of oil in the structure. Many geologists and petroleum engineers have considered all the oil in a petroleum reservoir to have uniform physical characteristics and that equilibrium conditions prevailed in all underground accumulations of oil and gas. That such is not always so is borne out by the results of the study made by the writers.

Jan 1, 1951

By S. Kraemer

Consumption of plastics has been growing in both the U.S. and world markets since the mid-1930s. This growth is due to plastics being used to make new products and as a replacement material for existing products. This paper develops an understanding of the replacement process by looking at the use of plastic, specifically PVC, in the construction pipe industry. History details the growth of the plastics industry and a discussion of the material selection process indicates the advantages and disadvantages of plastic pipe. Analysis shows that the use of plastic, as an alternative material for pipe, is having a significant effect on the cast iron, copper, clay, and steel industries. For the purpose of understanding the replacement process, three example residential systems were examined with a lifecycle cost analysis being performed. PVC was the material of choice in 1988 for all systems. Even though disposal cost was the one area where PVC was not the most cost effective, disposal costs were not sufficient to offset the overall advantage of using PVC on an economic basis. That plastic competes effectively with other materials, in terms of material properties and cost, indicates that further work should be performed to understand the impact plastics have on other material markets.

Jan 1, 1991

By Carl R. Peterson

This report describes the development and testing of a prototype tunneling machine. Principal efforts were aimed at testing of the fragmentation subsystem of a continuous drill and blast hard rock excavation machine suitable for use in underground mining and tunneling applications. The concept utilizes a unique self -shielding spiral blasting pattern that permits efficient performance with relatively small single shots, while at the same time directing major blast fragments at right angles to the tunnel axis. A major accomplishement was the development of a remote controlled, loading and initiation system in which explosive slurry and a detonator are Simultaneously placed (pumped) into the blasthole via a loading hose. The special electric long-delay detonator is inductively ignited upon emplacement, and the machine remains at the face during the blast.

Jan 1, 1976

By Fredrick L. Johnson

In 1986, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied 25,640 acres of the 29,680-acre Devil?s Garden Lava Bed, 21,040 acres of the 28,660-acre Squaw Ridge Lava Bed, and 9,100 acres of the 12,600-acre Four Craters Lava Bed Wilderness Study Areas (OR-D01-D02, OR-001-003, and OR-001-022, respectively) in order to evaluate their identified mineral resources. The study areas are located in Lake County, OR, about 50 air miles southeast of Bend. No mineral resources were identified in the three study areas. The areas are almost entirely underlain by recent lava flows. Cinder cones occur in each of the areas; however, the best cinder occurrences are in the Four Craters Lava Bed study area. Slab lava, of facing stone quality, is scattered throughout the Devil?s Garden Lava Bed study area, and to a lesser extent, in the Squaw Ridge Lava Bed study area.

Jan 1, 1987

By Michael S. Miller

The U.S. Bureau of Mines (USBM) conducted mineral investigations in the 1,227,000-acre Emigrant Trail study area of Nevada during 1992. During the USBM investigation of 25 areas of development interest, 190 mineral localities were identified and 260 rock and 50 alluvial samples were taken. At least 0.5 million troy ounces of gold, 2.3 million troy ounces of silver, 3.3 million pounds of copper, 10.9 million pounds of lead, 2.4 million pounds of zinc, 500 tons of alunite, 40,000 tons of sulfur, 9,000 pounds of mercury, and 21,000 pounds of tin have been mined from the area and vicinity. Adjacent to the study area, gold is being mined at large, open-pit gold mines, the Hog Ranch and Hycroft Resources, Inc., Sulphur mines, and new production is planned at the Rosebud LAC/Equinox. Hog Ranch mine is nearing depletion, but resources of more than 0.5 million troy ounces of gold and about 5 million ounces of silver are estimated for the Rosebud LAC/Equinox project and more than 0.4 million ounces of gold for the Hycroft Resources, Inc., Sulphur mine. Significant investigations are occurring at SP Ridge and other sites near Scossa and at the Dan claims in the Southern Calico Mountains. Precious opal, placer gold, and geothermal energy resources occur in the study area and vicinity.

Jan 1, 1993

By Jr. Denton

This U.S. Bureau of Mines report presents the documentation for HEAPREC, a methodology for calculating reclamation performance bonds for cyanide heap leach operations. HEAPREC is a template developed for use with Lotus 1-2-33 release 2.01 or newer software. The report is presented in step-by-step "user's manual" format. Appendices contain detailed background and reference material on performance bonding, cyanide detoxification regulation, cyanide detoxification methods, general mine reclamation procedures, and an example bond calculation.

Jan 1, 1992

By Robert J. Evans

The Bureau of Mines is sponsoring a variety of long-term, high-risk research to advance state-of-the-art technology in U.S. underground coal mining. This report reviews the status of many Bureau projects that support fundamental underground coal mining operations; the project areas include cutting coal from the solid (extraction), hauling coal from the face (transport), and activities that sustain daily operations (logistics). Innovative equipment and technology have been developed, with these major objectives: to significantly improve coal mine productivity, to further advance coal recovery and personal safety within the mining industry, and to reduce the time needed to develop longwall panels. The majority of the prototype equipment covered in this report either has undergone or will undergo comprehensive evaluation at Bureau surface test facilities so that performance and reliability can be improved before the equipment is tested and evaluated in a working section underground.

Jan 1, 1988

By E. C. Pattee

A mobile spectroscopic laboratory was completed by the Bureau of Mines in 195 to provide a rapid, inexpensive means of field testing samples for beryl¬lium and other associated metals of possible commercial importance. Spectro-copes have been used in laboratories for many years in various types of research and routine analyses, but this spectroscope is probably the first mobile unit. The laboratory provides for spectroscopic, radioactivity, fluorescent, and limited chemical tests of samples. The unit has been a valuable reconnaissance tool. It has been used to search for beryllium, cesium, columbium, tantalum, rubidium, and lithium in Idaho, Washington, and Montana. Several very low grade deposits of these elements were found, and occurrences of other important elements were identified; however, none are of economic importance. The spectroscope permits the detection of elements by analysis of visible light produced when elements in a small powdered sample are volatilized in an electric arc., A total of 70 elements can be detected; 29 can be detected at or below 0.01 percent, Electric power for the arc is supplied by a gasoline motor-driven generator, Equipment is housed in an aluminum van, mounted on a 4-wheel-drive vehicle for easy maneuverability on mountain roads, A trailer with crushing, pulverizing, and splitting equipment permits the reduction of samples to a small representative pulp.

Jan 1, 1963

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions4/ issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous .sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1958

By Graham W. Marks, Clyde A. Bridger

"INTRODUCTION An electrolytic process for the preparation of metallic cobalt has been developed recently in the Bureau of Mines Experimental Station at Boulder City, Nev. Chemical analysis shows this cobalt to contain impurities in small percentages, chief of which is nickel. It is desirable to be able to determine these impurities spectrographically. This report is concerned with a procedure for the spectrochemical determination of nickel in cobalt.Previous spectrographic work on cobalt was done by Breckpot and Mevis,/ who used the method of homologous pairs of lines. However, it was felt that a more detailed investigation was needed, employing the method of internal standards.ACKNOWLEDGMENTWe are indebted to B. G. Knickerbockor and his staff at the Boulder City, Nev., station of the Federal Bureau of Mines for their cooperation, and particularly to Richard W. Lewis and Robert G. Sanderson, who prepared nickel-free electrolytic cobalt for us."

Feb 1, 1948