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By Edwin E. Maust

In response to the ever- increasing demand for high temperature materials, the Bureau of Mines instituted a program for the study and development of superrefractories, One of the major tools obtained for use in this research was an image furnace of the double-paraboloidal mirror type. Although extensive theoretical analyses of solar furnace performance may be found in the literature, comparable detailed information on the double-paraboloidal-mirror image furnace has been nonexistent. This report presents an analysis based on an investigation undertaken to ascertain the limitations and characteristics of the furnace so that it can be used most effectively. The quantitative determination of the energy available at the image, the control of this energy by mans of a 60-inch iris diaphragm, and its variation with position and time relative to the heat source used have all been dealt with in detail. The quantitative results were obtained using a specially designed waterflow calorimeter and these measurements, in conjunction with the theoretical analysis, are used to present a fairly complete description of the furnace and its capabilities.

Jan 1, 1962

By M. W. Von Bernewitz

The Bureau of Mines receives frequent requests for information on the treatment of mercury ores, but as its own and almost all other publications on mercury are out of print, the Bureau has prepared this circular on the metal for the prospector and operator of small mines and plants. Mercury, commonly though improperly termed ?quicksilver?, is the only common metal that is liquid at ordinary temperatures. Mercury is used in the amalgamation of gold and silver, in power boilers, explosives, friction-less bearings, laboratory apparatus, lamps, medicine, paint, rectifiers, and for ?silvering.? The last mentioned is being superseded by silvering with silver. The use of mercury boilers may increase when they are thoroughly understood, but amalgamation is -being replaced to some extent by the use of corduroy and other collecting mediums, such as jigs and flotation cells.

Jan 1, 1937

By Thomas P. Mucho, Dennis R. Dolinar, Anthony T. Iannacchione

The Chestnut Ridge Anticline is a prominent structure in southwestern Pennsylvania, USA. This structure has brought two economically valuable limestone formations to the surface, where they are easily accessible to room-and-pillar mining. Nine active crushed stone quarries, an underground research facility, and one industrial facility currently operate along the linear trend that represents the axis of the anticline. The National Institute for Occupational Safety and Health (NIOSH) has identified significant variation in levels of horizontal stress within relatively short distances at shallow overburdens along the anticline. At one quarry, the horizontal stress is high enough to shear strata with a modulus of approximately 77 Gpa. Conversely, zones of extension were observed in parts of another quarry, indicating very low horizontal stress conditions. This study found that high levels of horizontal stress are to be expected in this very stiff rock formation and that local geologic and topographic structures are capable of altering the magnitude and possibly the orientation of the horizontal stress field.

By S. R. Borrowman

This investigation by the Bureau of Mines was undertaken to develop information on the extractive metallurgy of thorite ores because potential ore bodies of this mineral have been found recently in Colorado, Idaho, and Montana. Basic information on thorite ore treatment that would be useful in appraising the potential of these and other domestic thorium resources was developed. The work was done mainly on thorite ore containing 3.87 percent ThO2 from the Powderhorn district, Colo., and on a composite sample containing 0.52 percent ThO2 from the Wet Mountains district, Colo. Limited tests of d corroborative nature subsequently were made on a sample containing 2.30 percent ThO2 from the Lemhi Pass area on the Idaho-Montana border.

Jan 1, 1962

By C. C. Anderson

"While conducting investigations in connection with the helium program of the Bureau of Mines, the Cryogenic Laboratory has improved an apparatus for the rapid and accurate determination of the helium content of natural gas and gaseous mixtures derived from that source. The separation of helium is effected by the use of activated coconut charcoal which, when cooled to liquid-air temperatures, absorbs the nitrogen and other constituents of the gas, leaving the helium in a. spectroscopically pure state. This absorptive property of activated charcoal was discovered- by Dewar3/ in 1875. Several years later, while conducting their original researches on helium in natural gas, Cady and McFarland employed the charcoal method for the absorption and removal of the common constituents of natural gas and constructed an efficient apparatus in which this operation could be effected.4/ Shortly after initiating the government's helium activities during the World War period, the Bureau of Mines adopted, with Minor modifications, the Cady and McFarland apparatus and method of analysis. Seibel.5./ described this modified apparatus and method of procedure as part of a publication on helium-bearing natural gas. Subsequently, the Bureau's apparatus for helium analysis has been simplified and improved to facilitate more rapid and positive operation. The apparatus and method of procedure now being used by the Bureau of Mines Cryogenic Laboratory arc described in this paper.The personnel of the Bureau of Mines Cryogenic Laboratory has improved and brought the helium apparatus described herein to its present state of perfection. The writer's contributions have been-of minor importance, and he wishes to give the various members and former members of the laboratory staff full credit for the improvements they have made. He also desires to express his appreciation for suggestions and criticisms offered during the preparation of this paper to the following members of the Petroleum and Natural Gas Division, Bureau of Mines, which now includes the Amarillo Helium Plant and Cryogenic Laboratory: H. A. Cattell, chief engineer; C. W. Seibel, supervising engineer of the Amarillo Helium Plant; W. M. Deaton, chemist-in-charge of the Cryogenic Laboratory; and H. S. Kennedy.The quantitative determination of helium in a gaseous mixture is accomplished by the removal of the other constituents from the sample, either by chemical or physical Means, leaving only the helium which can be measured directly. Chemical methods, when applied to natural gas, require the burning of the hydrocarbons in oxygen, the, absorption of the resulting carbon dioxide in a caustic solution, the removal of the excess oxygen in a suitable solution such as an alkaline pyrogallate, and the elimination of nitrogen by sparking or by combination with hot calcium or magnesium.. Such procedures are very slow and tedious compared with the physical method which employs the absorptive property of activated charcoal to effect the separation of the other constituents from the helium."

Jun 1, 1934

By Oliver C. Ralston

The nonmetallic minerals work of the Bureau of Mines started with the organization of the Mineral Technology Division in 1912. A special experiment station devoted to the mining, preparation, and processing of nonmetallic minerals was established in 1923 at New Brunswick, N. J., and concentration problems on nonmetallic minerals of all kinds also were studied at the Mississippi Valley Experiment Station at Rolla, Mo. In July 1936 the Nonmetals Division was organized, and in May 1937 the Nonmetallic Minerals Experiment Station at New Brunswick, N. J., was moved to and made a part of the new Eastern Experiment Station at College Park, Md. At present the Nonmetals Division operates at three points: The Eastern Experiment Station, College Park, Md., which is headquarters for the division chief; the Southern Experiment Station, Tuscaloosa, Ala.; and the Northwest Experiment Station, Seattle, Wash., where coal washing and preparation studies are included with those on nonmetallic minerals. Sand, gravel, and aggregate work is carried on by the Mining Division, as sand and gravel preparation are intimately associated with mining methods. The Economics Branch of the Bureau of Mines also prepares occasional papers on nonmetallic technologic subjects in connection with the presentation of statistics on a particular industry and reviews of the mineral industry in foreign countries for use in the monthly publication, "Mineral Trade Notes."

Jan 1, 1937

This Bureau of Mines publication consists of an overview of the mine waste management research currently being conducted by the Bureau. The following papers, given at a Technology Transfer Workshop, emphasize the increasing importance of research related to the safety and environmental considerations of mine waste disposal In recent years. Current work related to legislation passed in the last 10 years and their subsequent standards includes the development of adequate monitoring systems, development of stability and seepage prediction and control techniques, control of runoff water, and control of leaching solutions. Selected topics are included here that cover coal mine waste disposal, embankment slope stability monitoring, flow failures of mine tailings impoundments, and controlled burnout of abandoned coal mine fires. The projects described provide a current documentation of problems being addressed.

Jan 1, 1981

[This Bureau of Mines report presents results of a survey of underground mining equipment and of two demonstration programs showing the feasibility If quieting; a load-haul-dump (LHD) machine and a personnel vehicle. Typical noise levels are presented for the major machine types used in underground mines, along with estimates of the noise overexposure of miners who operate or work near these machines. General principles of noise control are explained, and the application of these principles is illustrated in the description of modifications made to the LHD machine and the personnel vehicle. The noise control package installed On the persona of vehicle lowered its noise level by 14 dBA after 4 months of operation, and inspection of the LHD machine after 2 1/2 years of operation with the modifications showed its noise level 7 dBA lower than that of the unmodified machine. Noise dosimeter measurements indicated that both machines were in compliance with Federal noise regulations for a typical shift.]

Jan 1, 1980

By D. R. Dollnar

At a mine in central PA, high horizontal stresses have caused long running roof falls resulting in hazardous conditions for the miners and the premature abandonment of panels. Because of these conditions, the mine requested assistance of the National Institute for Occupational Safety and Health (NIOSH) in utilizing the 'advance and relieve method to mitigate the affects of horizontal stress on the mine roof. "Advance and relieve" mining involves the removal of a pillar or a portion of a pillar during development, thereby creating a cave along one side of the panel. Following cave development, the horizontal stress is relieved over the workings adjacent to the cave in the active panel. The mine has used this system in three panels with a significant reduction in stress damage and no large roof falls.

Jan 1, 2002

By H. M. Lawrence

"Florida, the State that supplied 82 per cent of the phosphate rock sold in the United. States in 19284, has two producing areas - the hard-rock and the land pebble districts. Production of the hard-rock field, decreasing importance in recent years, is now confined to mines near Dunnellon, in Marion and. Citrus Counties. The land-pebble district, with a production of almost 80 per coat of the nation's requirements, is located, in Polk and Hillsborough Counties. In the land-pebble area the phosphate deposits - probably Pliocene in age, derived by marine action from underlying, older, phosphate-bearing formations - consist of beds of phosphate matrix, covered by practically barren sands and clays. The overburden, ranging in thickness up to 45 feet, is removed by hydraulic methods or by drag-line excavators. The matrix, ordinarily less than 25 feet in thickness, is mined by hydraulicking and is pumped to adjacent washing plants for beneficiation. The dried product of the washing plants is the Florida pebble rock that is sold in foreign as well as domestic markets.The beneficiation of phosphate ores in the land-pebble district of Florida has been largely limited in the past to the recovery of the coarser pebbles. By washing and screening the crude matrix a separation is effected at about 20 mesh (0.033 inch). The coarser material is the phosphate-rock product of the plant and the finer material is discarded. The amenability of the washer- rejects to treatment by other processes is being investigated. Of methods that may have some application to the treatment of the low-grade phosphatic sands that comprise the greater portion of the washer-rejects, gravity concentration has received some study.Laboratory experiments to determine the amenability of phosphate sands to gravity methods of concentration were first performed in October, 1927. Later, in the winter of 1928-1929, a further series of teats was made,. In these later tests phosphatic sands were concentrated by hydraulic classification, and. also by hydraulic classification followed by tabling. In these experiments concentrates with an analysis above the minimum grade of commercial phosphate rock (66 per cent bone phosphate of lime - B.P.L.) obtained. The recovery of the phosphate varied but was promising enough to warrant further study. A more comprehensive investigation was therefore outlined. This paper presents the results obtained from an investigation, of classification and tabling of phosphatic sands recently completed by the United States Bureau of Mines Su cooperation with certain Florida phosphate companies, the Missouri School of Mines and Metallurgy, and the University of Alabama."

Jul 1, 1930

By C. Ogasawara

This document describes the direction and progress of the Bureau of Mines Oil Shale Mining Environmental Research Program as of January 31, 1979. It is aimed at focusing the Bureau's role in environmental research supporting oil shale development with respect to the activities of other involved government agencies and private industry. Environmental considerations in oil shale extraction, such as ecological disturbances, health and safety hazards, waste management, and socioeconomic impacts, are discussed along with the type of research known to be planned by organizations to ameliorate these problems.

Jan 1, 1979

By Frank B. Fulkerson

Aluminum production in the Pacific Northwest has a new potential for expansion and increased stability of operation. This new potential results from greater availability of power; lower freight rates on alumina and aluminum; good market prospects for the metal, including western aluminum market expansion following a decline in defense requirements in the 1950's; and possibility of developing bauxite deposits in the Pacific Basin as well as other mineral resources. INTRODUCTION This is a report of a special study by the Bureau of Mines of the primary aluminum industry of the Pacific Northwest. It outlines developments relative to the United States as a whole.

Jan 1, 1962

This three-part report provides the results of an industrial engineering study that assessed the safety and efficiency of underground ore handling in U.S. metal mines. One of the primary findings of the study was the improvement needed in controlling muck size in the are handling stream. Oversize ore is causing much additional labor, creating work stoppages, and is a principal cause of accidents in metal mines. The specific objectives of the Present Systems Study were to determine and evaluate the productivity of existing ore handling systems in a representative group of underground metal mines, to relate the available historical accident record statistics of these selected mines to the specific operations in the overall ore handling operations, and to highlight the potential areas of improvement for each mine on the basis of productivity and associated hazardous index for each operation.

Jan 1, 1974

By R. S. Dean

[During t!~c past f isc.~l y~:-.r the Xetzllvz-gicd 3ivi oion has made im- portant contribution-, don,- tlie lines rlictnteil by the Bureau policy of con- servation of domestic rnker~l rcsoul-ces throui;h use. During t!~c past f isc.~l y~:-.r the Xetzllvz-gicd 3ivi oion has made im- portant contribution-, don,- tlie lines rlictnteil by the Bureau policy of con- servation of domestic rnker~l rcsoul-ces throui;h use.]

Jan 1, 1940

This report includes a short history of uranium and its uses, mineralogy of common uranium minerals, and information on the use of electronic prospecting equipment and tests for detecting the presence of uranium. Details are given on geologically favorable areas and formations and practical methods of prospecting. Some information is given on the staking of claims, what lands are open to prospecting, and methods of securing mining rights. A forecast of the economic outlook for uranium is included. Appendixes give sources of additional information and a list of libraries where unclassified Atomic Energy Commission reports may be consulted. Because the increasing use of uranium by industry has revived interest in prospecting and exploration for this element, the Bureau of Mines has issued this report, which brings up to date and expands the subject matter of a hand- book on uranium exploration and production published in 1956.l

Jan 1, 1968

By Kenneth Eilerts, Vincent Smith

"INTRODUCTION Knowledge of the Phase relations of fluids produced from combination wells 4/ at the pressures and temperatures characteristic of production from natural reservoirs is essential to efficient recovery and refining practice. An accurate sample of the fluid from such wells may be prepared by mixing (in the proportions of the measured gas:liquid ratio) gas and liquid taken from the separator conditions of steady flow; and physical properties of the sample, at significant pressures and temperatures, may be determined with suitable laboratory apparatus for use in the solution of engineering problems. The results of study of sample so obtained and of mixtures of gas and liquid from the separator combined in other proportions are presented in this report. Attention was given in the study to the relationship between the physical properties of what may be regarded as the constituent materials - the gas and liquid taken from the separator - and the properties of mixtures of these constituents. Data obtained for the complete range of mixture Proportions are expected to provide a reference scale for the study of other combination-well fluids produced at different liquid:gas ratios."

Apr 1, 1942

By J. E. Allison

As part of a Bureau of Mines research program to conserve critical and strategic metals, an aqueous electrodeposition method for preparing stainless-steel-type coatings was studied. Chromium powder (averaging 3 J1.m diam) was suspended in a ferrous-nickelous sulfate electroplating bath and occluded in the electrodeposited Fe-Ni alloy matrix. Subsequent heat treatment of the resulting composite coating formed the ternary alloy. The occlusion process was affected by the quantity of Cr powder suspended in the electrolyte and by the microstructure and composition of the electrodeposited matrix. Coatings containing up to 21 wt pct Cr were deposited from an electrolyte containing 20 vol pct suspended Cr powder. Heat treatment at 1,100° C for 8 h homogenized the composite coating. Deposition of 44Fe36Ni20Cr alloy coatings (250 J1.m thick) on AISI 1020 carbon steel rods, followed by heat treatment, provided complete protection of the carbon steel during exposure to a boiling 65-pct-HN03 solution. Corrosion rates of 0.6±OA mm/yr for the coating in the boiling HN03 approximate that of 304 stainless steel. Practically shaped electroforms have been prepared by the coating method.

Jan 1, 1989

By R. L. Rough

Photoelastic, wire resistance, and borehole-deformation gages were used to measure the in situ strains when an outcropping Black Hand Sandstone Formation in Hocking State Forest, Hocking County, Ohio, was overcored to stress-relieve the surrounding sandstone. Strains transmitted to the photo-elastic gage did not produce isochromatic patterns suitable for quantitative analysis. Strain readings from the wire resistance gage indicated tensile-strain loading during overcoring; readings from the strain-gage bridges in the borehole-deformation gage indicated compressive-strain relaxation during overcoring. The magnitude and orientation of the computed stress fields obtained from both gages were comparable when the corresponding tensile and compressive elastic moduli were applied. Stresses computed from deformation and resistance gages at depths to 5 feet showed the maximum stresses to range from 1.042 to 2.121 times greater than the minimum stresses. The bearings of principal stresses calculated from the deformation gage readings varied between N 61° E and N 83° E; the wire resistance strain gage bearing computations varied between N 68° E and N 82° E. Measurements of in situ strain in sandstone were shown to have promise but to require further development in field technique that could likely be achieved through experience.

Jan 1, 1971

By J. E. Fraley

Full-column anchored resin bolts were first used in underground mines in 1972. These bolts appear to improve support in many roof bolt applications, as indicated by the use of about 30 million resin bolts in 1980. In the mid-1970's, Bureau of Mines in-vestigators began looking for a substitute for resin because of its short supply and rapidly increasing price. The investigators selected accelerated gypsum plaster (CaSO. ·1/2H20), which becomes gypsum (CaSO.· 2H20) when mixed with water. Gypsum makes an effective alternate grout material because it hardens quickly, is readily available, and is inexpensive in comparison with other cementitious materials. The Bureau received a patent (U.s. patent 4,096,944) for a system combining water capsules (wax-encapsulated water) with plaster into cartridges resembling resin cartridges. This report presents the results of tests conducted by the Bureau on the plaster, the water capsules, and their combined use in cartridges. The tests were designed to determine how the gypsum-plaster water capsule bolting system performs and what happens in the hole while the bolt is being inserted through the cartridge. The test results indicate that water capsule plaster cartridges are a workable alternative to resin cartridges under normal or dry conditions.

Jan 1, 1987

By Todd M. Ruff

This report summarizes ongoing research at the National Institute for Occupational Safety and Health, Spokane Research Laboratory, in which collision warning systems for surface mining dump trucks are being evaluated. Common accidents involve these large trucks running over smaller vehicles or pedestrian workers. Collision warning systems currently use one of several methods, including radar, radio-frequency-signal detection, or ultrasonic signals, to detect and warn of the presence of an object or person in the blind spots of the mining equipment. Most available systems have not been tested on large off-highway dump trucks. This report evaluates several systems on two sizes of trucks, a 50-ton-capacity truck commonly used in quarries and construction and a 240-ton-capacity truck commonly used in open-pit mines. Tests were conducted to determine false alarm rates, alarm effectiveness, and reliable detection zones for a person and a pickup truck. The results indicate that radar and radio-frequency identification systems show promise for this application and that several of the improved systems are ready for extensive field tests. However, challenges still exist in applying these technologies to large trucks.

Jan 11, 2000