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By C. R. Kuzell

This paper, describing the concentrator practice of the United Verde Copper Co., is one of a series being prepared by the Bureau of HISTORY The United Verde concentrator was constructed in accordance with recommendations based on certain novel reasons which were quite different from those usually justifying the expenditure of such an amount. Concentrator operations started in March, 1927, although the metallurgical staff had considered for several years the eventual addition of a concentrator department.

Jan 1, 1930

By R. E. Morgan

This publication presents abstracts of articles and investigations pertaining to the utilization of fly ash. The terms "fly ash" and "flue. ash," as' used in most of the papers, refer to the ash from pulverized-coal firing collected by electrostatic precipitators or mechanical collectors. Several investigators do not define the material on which they report beyond calling it fly ash, but they probably refer to the fine material resulting from burning pulverized coal. A few of the papers report on investigations involving not only the use of fly ash but boiler slag as well. These can be identified by the title of the articles. Bibliographical information and the abstracts are arranged according to the date the papers were published, with the most recent listed first. With the continually increasing use of pulverized-coal firing, profitable disposal of the fly ash is becoming a problem of greater importance to many utility and industrial companies. Also, in recent years, the public demand for cleaner air, and the more highly efficient fly-ash collectors available have resulted in the collection of a greater percentage of the fly ash produced. The solution to better utilization of fly ash has, therefore, been the object of research for some years.

Jan 1, 1952

By G. W. Weems

The Bureau of Mines used the Burnett method and apparatus to determine the compressibility factors for helium and carbon dioxide mixtures at 0°, 10°, 20°, 23°, and 35° C and to pressures of 900 psia. Tables of compressibility factors and approximations of the virial coefficients are presented for seven binary mixtures as well as for helium and carbon dioxide. The results compare favorably with existing data.

Jan 1, 1969

By Martin D. Conyac

Results of the minerals survey indicate low potential for the discovery of placer gold along Deck Creek aid for copper, silver, and gold in PreTertiary rocks within the boundaries of the Lake Fork RARE II area. Potential for oil, natural gas, coal, and geothermal resources is negligible. No evidence of economic mineral resources was found during the examination of the study area, and no assays of rock or placer samples taken from the urea showed economic mineral values. There are no producing or developing mines within the boundaries o of the lake Fork study area. SETTING Mining Districts The Lake Fork RARE II area is on the eastern fringe of the Cornucopia Mining District, which is centered about 6 mi west. It is also on the western edge of the Homestead district, centered about mi east.

Jan 1, 1983

By P. R. Tisot

Knowledge acquired from this research contributes to a better understanding of the physical structure of Green River oil shale and provides fundamental data and concepts that may serve to improve oil-shale technology. This study by the Bureau of Mines indicates that oil shale is a highly consolidated organic-inorganic system with no significant micropore structure, pore volume, or internal surface. This system is a form of physical structure that precludes rapid diffusion of either gases or liquids. The mineral matter consists essentially of nonspherical particles that tend to follow a log-normal size distribution. An excess of 99 weight-percent of these particles have equivalent spherical diameters of less than 44 microns--75 weight-percent are from 2 to 20 microns, and 15 weight-percent are less than 2 microns. The surface area (3 to 5 square meters per gram) of these mineral constituents is mainly external surface. The mineral constituents contain some micropore structure--pore radii ranging from 10 to 100 Angstrom--with the pore sizes randomly distributed. Distribution of the organic matter within the inorganic matrix is essentially interparticle and not intraparticle. The organic matter within the micropores of the mineral constituents is less than 4 percent of the total. Estimates made from surface area data suggest that perhaps only a small amount of the organic matter is bonded either physically or chemically to the mineral constituents.

Jan 1, 1963

By W. L. Dare

This information circular is one of a series the Bureau of Mines plans to publish describing the methods and costs of mining uranium on the Colorado Plateau. The Temple Mountain mining district is unique among the uranium-producing areas on the plateau. This relatively isolated mining district is in Emery County, Utah, on the eastern flank of the San Rafael Swell, about 35 miles southwest of the town of Green River. The district lies just within the eastern escarpment of the San Rafel Reef - a rampart of rugged and tilted sandstone cliffs that encircles the highly eroded core known as the Sinbad Country. The presence of petroleum matter found associated with the ore deposits, the occurrence of uranium in various formations, and the structural deformation caused by collapsed features have aroused a great deal of geologic interest. Mine development on Calyx Flat is distinctive, in that the ore deposits are worked through 36-inch calyx-drill holes.

Jan 1, 1957

By Gordon T. Austin

The combined production value of natural abrasives, which consist of tripoli, special silica stone, garnet, and emery, decreased in 1986. Shipments of processed tripoli increased slightly in quantity and 20% in value. Production of garnet, a common iron- aluminum-silicate mineral, decreased 12% in quantity and value. There was a 4% increase in the quantity and an 11% increase in the value of refined garnet shipped when compared with 1985 shipments, a new record high. Production of crude special silica stone decreased 7% in quantity and slightly in value, and shipments of finished special silica stone products decreased slightly in quantity and increased 229% in value. Production of emery, an impure aluminum oxide, increased 77% in quantity and increased 269% in value of product mined and shipped. [ ]

Jan 1, 1988

By Wallace W. Roepke

The Bureau of Mines studied the cutting characteristics of point-attack bits to reduce airborne respirable dust and energy during cutting. Linear cutting of two coal types using four bit types at three depths of cut with three space-depth ratios was performed with a modified horizontal milling machine using an optical particle-size monitor for respirable dust sampling. The cutting action of one bit on a rotary hardhead mining machine was mathematically analyzed and compared with the results of the linear cutting test. Airborne respirable dust per unit mass cut (specific dust) was found to be a monotonically increasing function of specific energy. Specific dust and energy decrease with increasing depth of cut. The amount of nonairborne respirable dust was 100 to 1,000 times greater than the airborne dust. The plumb-bob bit produced the most airborne respirable dust and the highest specific energy of the four bits tested. Rotary cutting was a greater dust producer and energy consumer than linear cutting because of the constantly changing depth of cut, space-depth ratio, and attack angle of the bit relative to the horizontal bedding planes. A new cutting technique is proposed to minimize the existing problems of the rotary cutting machines by providing greater production, reduced dust, and minimized methane ignition potential at the face.

Jan 1, 1976

By Andrew Cecala

The Bureau of Mines performed tests to compare the effectiveness of steam and of water sprays to reduce respirable dust levels at mineral processing plants. By applying 0.22 wt pct water vapor as steam to product material, a 64-pct respirable dust reduction was recorded. By applying the same amount of moisture with water sprays, only a 25-pct dust reduction was recorded. By increasing the moisture content up to0.5 pct using water sprays, the dust reduction was increased to 55 pet, which was still less than the dust reduction achieved by adding less than half that amount of water in the form of steam.

Jan 1, 1985

By Donald E. Redmon

This Bureau of Mines report reviews injury experience in the nonmetallic mineral industries (except stone and coal) for 1968-69. For each of the years, 23 tables summarize disabling work injuries by department, source of injury, extent of disability, part of body injured, and nature of injury. Correlative information on employment, worktime, and operating activity is also presented.

Jan 1, 1973

By Lloyd Williams

A vertical air shaft in the Birmingham, Ala., iron district was sunk with a circular cross section and lined with concrete at a relatively low cost to provide needed ventilation for an iron-ore mine. The method of sinking the shaft is described, and the costs are stated in mar-hours with a descriptive list of equipment and a statement on the size and use of temporary buildings. Preparation began May 2, 1955, and the shaft was completed at a depth of [680] feet by September 22, 1956. By October 1956, all temporary building and [aft]-sinking equipment had been removed. The total direct-labor cost for the operation, including preparation and dismantling, was 50,700 man-hours, or 30.2 man-hours per foot. Total rock and dirt removed amounted to 17,523 cubic yards (in place), and the shaft lining required 4,635 cubic yards of concrete to form a circular air shaft with an inside diameter of 16 feet.

Jan 1, 1960

By C. E. Jordan

The Bureau of Mines is conducting research into the pneumatic recovery of coarse mica and has used this method to produce mica concentrates that contain more than 90 percent mica. This research is being carried out pursuant to the Bureau's objective to develop technology that will help maintain an adequate supply of minerals and metals to meet national economic and strategic needs. Researchers used a Bureau-designed system of crushers, screens, and zig-zag air classifiers to concentrate coarse liberated mica particles from mica-bearing materials. This pneumatic system was used to concentrate four mica ores from Arizona, North Carolina, and South Dakota and three waste tailings from Alabama, Georgia, and South Dakota. Using these samples, it was demonstrated that plus 65-mesh size mica can be effectively recovered by the pneumatic method. Not only were the concentrates high in mica content; it was also demonstrated that this method can be used to recover up to 78 percent of the mica that was originally contained in the samples. Because it is a dry concentration method, the pneumatic beneficiation technique may be advantageous in areas where water resources are limited.

Jan 1, 1980

By B. J. Moore

This Bureau of Mines publication contains analyses and related source data for 276 natural gas samples from 23 States. All samples except four were collected during calendar year 1984. Those four samples were collected earlier, but releases granting permission to publish were not received until 1984. All samples were obtained and analyzed as part of Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. This survey has been conducted since 1917. The analyses published herein were made by the mass spectrometer and chromatograph. The results of these investigations are published annually to make the information available to the petroleum industry and the general public. Twenty-eight publications have presented the results of 13,957 gas analyses made prior to 1984. The first three bulletins (1-3)2 contain analyses and related source data on 5,218 gas samples collected from 1917 through 1960; these bulletins have been supplemented annually by information circulars (4-17, 19-24, 26-28) containing 8,453 analyses of samples collected since 1960.

Jan 1, 1985

By L. E. Schultze

The Bureau of Mines has devised techniques to recover lithium from geothermal brines as the chloride. More than 99 pct of the lithium was precipitated from a brine containing 170 mg/L Li by adding a solution of AICl3 and increasing the pH to 7.5 with lime slurry. The Li-Al precipitate was dissolved in HCl and sparged with gaseous HCI to recover the AlCl3; this resulted in a solution containing LiCl and CaCI2. The solution was evaporated at 1000 C to obtain a mixture of the chlorides from which 97 pct of the lithium was recovered and 90 pct of the calcium was rejected by leaching with tetrahydrofuran. The LiCl recovered by evaporation of the tetrahydrofuran was purified by dissolution in water and treatment with oxalic acid. The final LiCl solution contained 89 pct of the lithium originally present in the brine and had a purity of 99.9 pet.

Jan 1, 1984

By D. J. Dollhopf

The specific objective of this three year study is to investigate the means of reestablishing non-polluted hydrologic systems in areas where surface mining directly impacts shallow ground-water resources. The research area chosen for the study is located near Colstrip, Montana it a new mine site where chemical analysis of core samples from the overburden suggested that excessive concentrations of several elements would he encountered during the mining process. This report discusses local vegetation; soils; and regional geology, and hydrology. Stratigraphic cross sections and regression analyses were used to study the litho-chemical relationships in the overburden. Cross sections indicated Inimical material may be related to both rock tune and position within the overburden profile. In overburden zoness where clay content was high, there was a greater probability that Pb, Cu, Ni, and Mn concentrations would also be higher than average; similarly, the likelihood of overburden exceeding a suspect level became less as the sand content increased. Highest value, of conductance were usually found within a few meters of the surface. High concentrations of clay, nickel, and zinc were frequently found directly above and below the Rosebud coal. Regression analysis indicated overburden SAR was predictable with only a Na analysis. A strong relationship also existed in the overburden between conductance, Ca, and Mg.

Jan 1, 1977

By Francis E. Federspiel

Silver and gold are the principal metals in the study area; they occur in quartz veins or silicified portions of shear zones. In some deposits, lead, antimony, zinc, and molybdenum are associated with gold and silver. A uranium-bearing buried stream channel lies near the southern boundary. Since 1850, more than 300 lode claims and relocations have been recorded mainly in the southeast corner of the study area (fig. 1). Complete mine production records are not available; however Clark (1977, p. 28) reported less than $300,000 of gold and silver were produced, mainly from the Exchequer, IXL, and Pennsylvania Mines. Other mines in the area probably yielded are before 1900, but early records are not available.

Jan 1, 1981

By Frank C. Morris

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

Jan 1, 1957

By Elio Ferreira

This report describes the design, and development work performed to reduce the volume and weight of the miners caplamp battery, as well as a headpiece with a swivel mechanism containing a halogen bulb with two filaments. Work was also conducted in the development of a maintenance free battery. The design concept is based on non-sintered Ni-Cd technology, with an energy density of 22 Wh/lb. The cap lamp system developed has been approved by the Mine Safety and Health Administration (MSHA) and can be manufactured for mine use.

Jan 1, 1988

By George A. Morgan

The 53 countries that constituted Africa in 1989 accounted for a significant portion of total world output of a number of mineral commodities. Among the most significant minerals to be produced in Africa were andalusite, antimony, asbestos, bauxite, chromite, coal, cobalt, copper, diamond, fluorspar, gold, lithium minerals, manganese, phosphate, platinum-group metals, and the titanium minerals-ilmenite and rutile, vanadium, vermiculite, and zircon. Despite the underdevelopment of much of Africa, mineral raw materials played a very important part of the national economies of many of its countries. In terms of percent-age of export earnings, minerals accounted for more than 90% in some cases. In several countries with agrarian economies and little economic diversification such as Angola and Guinea, a single mining operation could represent an important source of foreign exchange. These latter operations tended to be the more easily mined surface deposits of diamond, gem stones, and precious metals. Mineral commodities for which Africa had a high percentage of world output were bauxite, 16%; chromite, 44.5%; cobalt, 76.5%; copper, 13.9%; diamond, 50.7%; gold, 32.9%; manganese, 27.1 %; phosphate, 22.1 %; platinum-group metals, 48%; uranium, 29.2%; vanadium, 54%; and vermiculite, 41 %. Several of these, chromite, cobalt, diamond, and manganese, were not produced in the United States.

Jan 1, 1992

By C. M. Frost

Two Federal Bureau of Mines recycle hydrogenation experiments to prepare catalytic cracking feed stock were made at 3,000 pounds pressure with crude shale oil retorted from Green River (Colo.) shale in the gas-combustion retort. The hydrogenated product from the first experiment, made at 784° F., was used for investigating the effects of nitrogen content on catalytic cracking yields and for determining the quality of the catalytically cracked gasoline. Hydrogenated product containing 0.14 percent or more of nitrogen produced less gasoline when cracked in a CAT "A" unit than was obtained from East Texas light gas oil cracked at the same conditions; product containing 0.10 percent or less nitrogen produced a quantity of cracked gasoline equal to that obtained from the East Texas light gas oil. The catalytically cracked gasoline had research octane numbers calculated to be approximately 95 clear and 103 with 3 ml. of tetraethyl lead. The principal product from the second experiment, made at 828° F., was a low nitrogen content gas oil which was used for investigating the yields of cracked products obtained when it was catalytically cracked to different degrees of conversion. Yields of cracked products, when plotted as functions of conversion, were essentially the same, within the experimental range of the data, as published yields from catalytic cracking of East Texas heavy gas oil; however, yields from cracking the shale-oil product did not display the sensitivity to change of cracking temperature that has been found for East Texas gas oil.

Jan 1, 1960