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By Donna D. Harbuck

The Bureau of Mines has investigated a process to produce titanium powder directly from titanium salts. If successful, such a process could lower the cost and increase the use of titanium. In this study, K2TiF6, K2TiF3, and TiF3 were reduced with potassium in the temperature range of 650° to 750° C. Under certain conditions, titanium powder 1.6 to 3.3 microns in size was produced. After leaching the product with a 0.1M HCl solution, powder impurities as low as 0.04 pct potassium and 0.28 pct fluorine were obtained. However, oxygen levels of over 1 pct and the frequent formation of insoluble byproducts demonstrate the need for further research to make the powder suitable for powder metallurgy applications.

Jan 1, 2011

By E. E. Maust

The literature on the activation of sphalerite for flotation by short¬chain xanthates leaves unanswered the question of whether a compact surface film of activator sulfide is necessary or merely sufficient for high flotation recoveries. Studies by Guarnaschelli and Plaksin indicate that xanthate adsorption and flotation of sphalerite are increased with increasing hole/ electron ratio. These results, and the known acceptorlike behavior of many heavy-metal impurities in zinc sulfide, suggest that activation may result from a traditional semiconductor doping effect at the surface. Using the theory of chemisorption states on ionic crystals as developed by Levine and Mark, the Bureau of Mines has carried out A calculation to estimate the surface-state energies of various metals when they are substituted at zinc sites on (110) sphalerite surfaces. Based on a simple Madelung-Born treatment of ionic solids, the calculation indicates that many of the metals known to activate sphalerite for subsequent flotation have lower surface-state energies than nonactivators. The results of these calculations are discussed from the standpoint of consistency with the proposed activation mechanism and observed flotation results. The satisfactory agreement obtained is taken to be support for the proposed mechanism, and further elaboration of a surface-doping model is attempted.

Jan 1, 1976

In 2007, a total of 7,199 sand and gravel mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 ? Sand and gravel mines were the largest mining sector, comprising 48.4% of all mining operations. ? Sand and gravel mines were found throughout all 50 states and Puerto Rico.

Aug 1, 2009

By Thomas J. Peters

The Danskin/South Fork Boise River study area is 40 air km southeast of Boise, Idaho. The 16,000-hectare, two-segment area is mainly underlain by Cretaceous-age granodiorite and an aplitic and pegmatitic complex of the Idaho batholith, Miocene-age rhyolitic tuffs and lavas, and late Tertiary-age basalt flows. No mineral resources were identified in the study area. One mine, The Flat Creek mine, which produced several ounces of gold and silver, was found in the study area. It is geologically similar to deposits in the Neal mining district, adjacent to the northwest corner of the area; gold mineralization occurs along east-northeast-trending faults and associated quartz veins, which dip moderately to steeply southeast, and within adjacent Cretaceous granitic rock. Samples indicate the Flat Creek deposit is not rich enough to mine underground, and near surface, open-pit-mineable deposit areas could not be identified. However, exploration is warranted there and also in the 7-km interval to mines in the Neal district, and for extensions of those mines. No evidence of geothermal activity was observed, although there are hot springs in the vicinity. Some alluvial (placer) samples from the interior of the study area contained free gold, but no substantial gravel deposits were seen.

Jan 1, 1993

By Thomas Varley

"The literature on flotation of oxidized ores except for patents (especially for reagents) is very sparse. The Bureau of Mines in 1936, published a circular on the subject, by Ralston and Allen. The treatment of oxides by flotation was then in its infancy, but several of the most important mining companies in the Western United States and Mexico are now operating flotation plants for treating oxidized ores. The purpose of this present circular is to review the progress made and bring the subject up to date. One of the writers of the 1916 report (Mr. Allen) has been associated with some of the most important mining companies who have put into practical operation the process of flotation of oxidized ores; among these companies are the Shhttuck Arizona Copper Co., Bisbee, Arizona (now the Shattuck Denn Co.) and the San Francisco Mines of Mexico, Ltd., San Francisco Del Oro, Chihuahua, Mexico. His experience and other sources of information have been freely drawn on in pre-paring this paper. Mr. Ralston, assistant chief metallurgist of the Bureau of Mines, contributed many valuable suggestions and criticisms.Sulphidizing Reagents for Oxidize Ores.The various reagents and methods that might possibly be used for sulphidizing were summarized by Ralston and Allen as follows:""Sulphidizing (1) by the use of hydrogen sulphide on either the dry or the wet crushed ore, (2) by the use of solutions of the various sulphides and sulpho-compounds of sodium, (3) by the use of solutions of the various sulphides and sulpho-compounds of calcium, (4) by the use of sulphur vapor, (5) by the use of a sulphureted oil, (6) with colloidal sulphur."

Jun 1, 1927

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 instructions2 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; 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, 1971

During 1990-1999, a total of 458 fires occurred in all coal mining categories; 157 of those fires caused 164 injuries and 2 fatalities. The greatest number of fues and fire injuries occurred at surface mines, whch also had the highest risk rate values. A total of 66 fuefighting interventions were required. Of these, there were 25 mine rescue team interventions in underground mines, including 5 mobile equipment firefighting interventions, and 41 fire brigade and fire department interventions at all surface operations, including 19 mobile equipment interventions. In all, 50 fires destroyed or heavily damaged equipment (including 16 pieces of mobile equipment) because of failure of other firefighting methods, late fire detection, undetected fires, or fire size. A total of 1 14 fires were detected late by smoke, and 42 fires were not detected.

By Thomas J. Peters

In 1978, the U.S. Bureau of Mines and the U.S. Geological Survey completed a joint mineral survey of the Chemise Mountain and King Range study areas as mandated by the Federal Land Policy and Management Act of 1916, Public Law 94-579. The U.S. Bureau of Mines examined all identified mineral prospects and deposits; the results of these examinations are included in this report. The U.S. Geological Survey studied the regional geology, geochemistry, and geophysics; the results of these studies are available in USGS Map MF-1196. No mineral resources were identified in either the Chemise Mountain or King Range study areas; however, a high-grade silver and base-metal occurrence, and minor manganese resources were identified in between the two study areas, within the King Range Conservation Area. The only mining activity in either area was a placer gold prospect on Honeydew creek in the northeastern part of the King Range study area. Three samples from this prospect contained no gold. The Chemise Mountain and King Range study areas are in a mountainous region along the coast of northern California, 230 road miles north of San Francisco, and 70 miles south of Eureka by way of U.S. Highway 101, through Garberville and Redway. The Chemise Mountain study area consists of 3,941 acres; it includes the 2,598-ft Chemise Mountain, and the cliff-lined seacoast southeast of Shelter Cove. a resort and fishing village. The King Range study area consists of 39.764 acres northwest of Shelter Cove, and includes the northwest-trending King Range with elevations above 4,000 ft. The Chemise and King Range study areas are underlain by deep-water marine sandstones, shales, and minor pillow basalts of the Late Cretaceous and early Tertiary Franciscan Subduction Complex. Mineral production was 1,650 tons of manganese ore within a manganiferous bed overlying pillow basalt at the Queen Peak mine southeast of the King Range study area. However, no significant manganese resources were found in the Queen Peak area. The Point Delgada area, directly south of the King Range study area, has prospects with high grade copper, lead. silver, and zinc. Exposures are inadequate to estimate resources; however, the metals may be associated with Franciscan volcanism (volcanogenic). The Chemise and King Range study areas may contain similar economic silver-rich, base-metal deposits.

Jan 1, 1992

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

By H. D. Kline

Manganese ores have been mined in the Batesville district since 1849. Although not continuous over the intervening years, production had totaled approximately 432,000 tons of manganese ore and ferruginous manganese ore to the end of 1953. The ores occur in deposits, essentially low in manganese content, distributed over an east-west belt 24 miles long and 4 to 8 miles wide, the core of which is about 6 miles north of Batesville, Independence County. Although the reserves of high-grade ores in the district are comparatively small, the large deposits of subgrade ores and low-grade manganiferous material comprise potential sources of supply of manganese that may have increasing future importance. The manganese occurs as primary oxide and carbonate minerals in relatively flat-lying limestone and shale formations in which they were originally deposited and as oxides in residual clays resulting from decomposition of the shale and lime-stone. Most of the deposits underlie from a few to over a hundred feet of sedimentary chert, but many occur in the residual clays on exposed slopes of chert-covered hills.

Jan 1, 1956

By Eric E. Ungar

Some fundamental facts regarding noise are summarized. Guidelines for reducing plant noise are indicated, and simple means are discussed for determining, whether quieting of specific equipment items will reduce plant noise significantly. Design and installation recommendations are made for quieting chutes by means of dams, impact cushioning pads, impact shields, and damping materials, and for quieting; screens by means of resilient decks, lined screen bottoms, drive mechanism enclosures, and side plate additions. A brief account is appended of the wear and productivity performance of resilient materials observed in three cleaning plants.

Jan 1, 1976

By Mackenzie Burnett

A high efficiency ejector has been developed which solves the abrasion problem associated with remote pneumatic stowing. The system can also produce cemented fills. The ejector is capable of moving the fill material over 70 ft from the injection point and filling the mine opening to the roof level for a distance of about 30 ft in all directions from the borehole. This system operates by the transfer of momentum from a supersonic air stream to the fill material. The momentum transfer results in a horizontal stream of fill material and air at a velocity of about 100 fps. The ejector fits on the bottom end of a 3 in diameter vertical pipe. Fill material is fed into the ejector at a controlled rate through a hopper mounted over the borehole. High pressure air used to operate the ejector is fed through a second 3 in diameter pipe. This system has the additional feature of mixing water in the air stream which increases the potential momentum of the air stream. Where necessary, cement can be added to the gravel to create a cemented fill. The design parameters and test results for four versions of the ejector are presented in this report.

Jan 1, 1991

By Richard A. Winters

In 1987, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 34,680-acre Lime Canyon Wilderness Study Area (NV-050-231) to evaluate its identified mineral resources. The Wilderness Study Area is in Clark County, NV, about 30 air miles southwest of Mesquite, NV. The area studied contains an estimated 44 million tons of indicated subeconomic resources of gypsum, an inferred subeconimic resource of limestone and dolomite, and occurrences of gold, copper, uranium, and zeolite. The Wilderness Study Area is underlain chiefly by carbonate rocks with lesser amounts of sandstone and shale. Metamorphic, granitic, and volcanic rocks also crop out within the area. Large portions of the area are overlain by alluvium. The Wilderness Study Area is within the Gold Butte mining district. Several gold mines with past production are nearby to the south of the Wilderness Study Area; one mine is reported in operation on a small scale. Several silver-bearing copper and zinc mines with past production are nearby to the east of the Wilderness Study Area

Jan 1, 1988

By Harry R. Nicholls

Preliminary tests on presplitting rock in the presence of an in situ static stress field were undertaken to study the influence of a horizontal static stress field on the creation of a vertical presplit fracture plane. These tests indicated that it is easier to fracture the rock parallel to the in situ maximum compressive stress than in other directions. Instrumented shots indicate that the interaction of stress waves generated by the detonating charges is probably responsible for starting tensile fractures between shotholes and that expanding gases may propagate these initial cracks by a wedging action. The hole spacing for presplitting appears to be equal to the half wavelength of the stress wave. However, wider hole spacing appears feasible if the initial fracture is started by closer hole spacing.

Jan 1, 1966

By P. J. Coleman

Research in the field of mining safety and health in the United States plays an important part in protecting the lives of miners. The National Institute for Occupational Safety and Health (NIOSH) Mining Program conducts surveillance, studies and developmental work aimed at improving the safety and health of miners. With recent reviews of the Mining Program by the National Academy of Sciences and the Mining Program response (NIOSH, 2008), the importance of setting goals, conducting high quality engineering and scientific research and evaluating the outputs, outcomes, relevance and impacts of these projects has been reemphasized. Surveillance of reported injuries is a first step in deciding on research directions and in designing specific projects. Groups of injuries often share features and attributes that suggest common causes and may respond to similar preventive efforts. Identifying groups of injuries also serves to prioritize intervention efforts. The Mine Safety and Health Administration (MSHA) Accident and Injury database (MSHA, 2008) provides individual case reports of mining injuries, illnesses and certain no-injury accidents (events such as roof falls that stop mine production or miners? activities for more than one hour). This database is an indispensable resource for researchers and stakeholders needing information on the statistics of these events. From an epidemiological perspective, research projects target groups of miners at risk due to specific patterns of work, equipment, mine settings and the management of safety and health in their mines. Incidence rates are provided by the MSHA data for selected variables, such as surface/underground location, standard industrial classification and state. While incidence rates are the preferred measure for all variables, denominators are not typically available; for example, to more clearly under-stand the data about injury by occupational type, it would be necessary to conduct demographic surveys. A current survey of the demographics of the mining industry should be complete by 2010, which will allow incidence rates to be developed for a number of variables such as age, occupation and experience. This survey will provide the first update of its kind since the first survey was conducted in 1985.

Jan 1, 2010

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 S. J. Pearce

The need for a simple, very sensitive, and accurate method for the determination of benzene in blood and urine vas evident throughout a recent study of chronic benzene (C6H6) poisoning conducted cooperatively by the United States Bureau of Mines, The Barrett Company, and the producers of benzene. A combustion method which will be described in a later publication, and a previously described/ adaptation of Smyth's method were developed and used during that investigation. The adaptation of Smyth's method gave satisfactory results when dealing with exposure conditions that produced chronic poisoning in a comparatively few days, but it was time-consuming; and lacked the accuracy necessary for a study of the absorption, distribution, and fate of benzene in the body during exposure to threshold concentrations of benzene vapor in air. The combustion procedure was satisfactory from the standpoint of sensitivity but was cumbersome, intricate, time-consuming, and required the use of special and somewhat expensive Physical and chemical apparatus. Following the termination of this study of chronic poisoning, possibilities ides for developing better methods occurred, and these have been investigated by the Bureau of Mines with the aid of Relief Works Division personnel microcolorimetric method for the determination of benzene in air has been described recently.6/ The present report deals rich the adaptation of this new colorimetric method to the determination

Jan 1, 1936

By Wm. F. Netzeband

The purpose of this paper is to present to the operators, in other districts a detailed description of the ruining method used and the results obtained to exploiting one of the zinc-lead deposits of the Kansas-Oklahoma-Missouri district. No. 1. mine is located in the heart of the town of Picher in the extreme northeast corner of Oklahoma. HISTORY The first prospect drilling was done at No. 1 mine late in-1914, and shaft sinking was started early in 1915. Sufficient ore was developed to start construction of the mill in April, 1016, Production begin in August, 1916, and the mine s been producing, except for short periods, to the present time. The property was originally a 40-acre tract, but additional properties have been consolidated with the original one until the mine now covers 200 acres.

Jan 1, 1929

By J. S. Gomer

The U.S. Bureau of Mines conducted Cu exchange tests for six common clays under simulated in situ leaching conditions. Regression equations were obtained from the data expressing the Cu exchange capacity as a function of Cu concentration, pH, and temperature. Using these equations, an analysis was made of the impact each clay could have on overall Cu recovery. The results suggest that Ca and Na montmorillonite clays could have a major impact on Cu recovery and that attapulgite and illite clays could have a smaller, but still significant, impact. Kaolinite and ripidolite clays pose little threat to loss of Cu from in situ leaching solutions.

Jan 1, 2010

By J. S. McNabb

"A search for manganese ore by core-drill exploration was carried out by the Bureau of Mines in the Philipsburg mining district in Granite County, Mont., in 1939 and 1940. This work was based on detailed studies of the manganese ore bodies of the district previously made by the Geological Survey.In 1949 further search for manganese in the district was deemed advisable. Diamond drilling was begun the following year as a joint program by the Geological Survey and the Bureau of Mines with the primary purposes of probing ore-leasing structures and extending the limits of known ore bodies. A secondary objective was to test a geologic theory based on a new conception of manganese-ore localization. The exploration targets were designated and the drilling results interpreted by the Geological Survey, and the Bureau of Mines was responsible for the drilling, sampling, and core handling. Improved drilling equipment and methods were utilized in an effort to obtain better core recoveries than resulted from the earlier drilling campaign.The Philipsburg mining district, Granite County, Mont., is 27 miles south of Drurrnnond, about 45 miles airline northwest of Butte, and 1 mile east of Philipsburg. During the course of the investigation patented lode-mining claims owned by the American Machine & Metals, Inc., the Contact Mines, Inc., and the Moorlight Mining Co. were diamond drilled.The district has been an important source of domestic manganese dioxide ore since local recognition of the mineral's importance during World War I. Peak annual output in 1918 of about 127,000 tons of manganese ore was utilized principally by the steel industry. A small but relatively steady output has persisted to the present to satisfy demands by battery manufacturers for battery-grade manganese dioxide.The known manganese deposits of the district are in sedimentary rocks of Paleozoic age. These rocks lie along a north-trending anticline traversed by a series of east-west tension veins. The east flank of the anticline terminates at a steep-dipping fault contact against a small granodiorite batholith.Replacement deposits of manganese oxides and carbonates occur locally in or closely associated with tension veins cutting calcareous rocks, or adjacent to the intrusive. Rhodochrosite has been a common accessory mineral in deposits valuable chiefly for lead, zinc, and silver. Some of the replacement deposits characteristically are irr2gular in outline, whereas others have fairly regular walls marking the limits of favorable beds."

Dec 1, 1955