Search Documents

By James A. Browning

Conventional flame channelling operates continuously at over 120 db --flame-drill channelling at a maximum of 95 db. The latter process was developed under this program. Individual drill holes are spaced to leave narrow rock webs. Sound and dust passing from the hole are effectively treated by a muffler and water injection.

Jan 1, 1980

By W. F. Wyman, S. F. Ravitz

"INTRODUCTION By far the greater part of the high-grade manganese ore used in the United States is imported from overseas. During the early part of the recent World War importations of manganese ore were seriously threated, and it appeared that it would be necessary to utilize low-grade domestic ores to the fullest possible extent. Among the processes that appeared to offer the best possibilities for beneficating low-grade domestic oxide manganese ores, which ordinarily are net readily amenable concentration by ore-dressing methods, were those involving leaching with sulfur dioxide. The Bureau of Mines therefore investigated the amenability of a large number of such ores to sulfur dioxide leaching.Several sulfur dioxide processes for beneficiating low-grade oxide manganese ores have been proposed. 3/ One of these, based on a patent by Van Arsdale and Maier, 4/ was used recently in a plant constructed to treat 1,000 tons per day of 20-percent manganese ore from the Three Kids deposit near Las Vegas, Nev. 5/ In this process the ore slurry is leached with sulfur dioxide gas, the resulting solution is evaporated to crystallize the manganese sulfate, the crystals are decomposed thermally to produce high-grade manganese oxide and regenerate sulfur dioxide, and the manganese oxide product is nodulized. The Bureau of Mines has recently developed a process 6/ in which a suspension of the ore in calcium dithionate solution is leached with dilute S02 gas, the manganese is recovered from the resulting solution by a simple lime precipitation, and the precipitate is nodulized or sintered to form a high-grade manga¬nese oxide product."

Jun 1, 1947

By W. L. Falke

The Bureau of Mines has developed a system that permits the "soft" soldering of aluminum and aluminum alloys with standard tin-lead solders. The method employs application of a thin nickel-copper-alloy coating to the substrate, which enables the tin-lead solders to wet readily and spread over the areas to be joined. With conventional technology, aluminum and aluminum alloys are extremely difficult to solder because tenacious surface oxide films prevent wetting. With the Bureau-developed method, the aluminum substrate is mechanically or chemically cleaned to facilitate bonding to a minute layer of zinc that is subsequently applied with an electroless zincate solution. The nickel-copper-alloy (30 to 70 pct Ni) coating is then applied electrolytically over the zinc, using immersion cell or brush-coating techniques. Development of acetate electrolytes has permitted deposition of the proper alloy coatings. The coated areas can then be readily joined with conventional tin-lead solders and fluxes. The joints so formed are ductile, strong, and relatively corrosion resistant, and exhibit strengths equivalent to those formed on copper and brass when the same solders and fluxes are used. The method has also been employed to soft-solder magnesium alloys.

Jan 1, 1983

This report is a compilation of all information obtained in accordance with the requirements of contracts SO122076 and H0232056. A series of eight coal mines were visited to determine their communications usage and requirements. Presently available equipment was surveyed and evaluated to determine its applicability to the needs of the mines. The equipment studied includes that made by the following companies : Anaconda Telecommunications Division Andrew Antenna Bendix Communications Division Collins Radio Group of Rockwell International Executone Communication and Sound Systems Gau-tronics Mine Safety Appliances Company Motorola Communications and Electronics, Inc National Mine Service Company Plessey Communications Systems Corp Pye Electronics Limited Reach Electronics Set Com Corporation Sonex Incorporated Mine visits and in-depth interviews were made alt the following sites: Robena No. 4, Pennsylvania Greenwich Colliery Mines, Pennsylvania Somerset Coal Mine, Colorado Keystone No. 1, West Virginia Harris Mine No. 1, West Virginia Baldwin Underground No. 1 Mine, Illinois Lovilia No. 4 Coal Mine, Iowa Orient No. 3 Coal Mine, Illinois

Nov 15, 1974

By Lloyd A. Morley

This annual report details progress under USBM Grant G0155003 during the project period of January 1, 1977 through December 31, 1977. The report contains four principal chapters covering accomplishments in the mine electrical safety research areas of continuous monitoring, battery and battery-charging safety, and computer modeling. Highlights of the work are summarized in the last report chapter.

Jan 1, 1978

By James Gibbs

In order to provide an initial approach to the deposits of oil shale, nahcolite, and dawsonite in the central area or the Piceance Creek Basin in northwestern Colorado, the U.S.B.M. and associated contractor personnel drilled and cased a 96-inch ID shaft to a depth of 2,371 feet. The shaft was constructed using ?big hole? drilling techniques and succeeded in giving access to previously inaccessible deposits of the above minerals. This report documents the construction from its beginning in January 1977 to its completion in January 1978. Procedures used and problems encountered are discussed in detail.

Jan 1, 1978

By P. A. Lawless

The objective of the research performed A for the Bureau of Mines on this contract was to develop a portable instrument for the detection of carbon monoxide (CO) in a mine environment. The desired characteristics were sensitivity and specificity for CO with a stable calibration. The sensor of the instrument was to be of metal oxide composition, requiring low power for compatibility with the types of batteries presently used in personal equipment in mines. The solid state design was also desired for ruggedness and small size. A key design feature of the instrument was to be provided by adherence to the intrinsic safety design requirements for electrical equipments operated in potentially exposive mine atmosphere. The Research Triangle Institute has prior experience in developing a solid state oxygen sensor using a thin film of zinc-oxide (Ref. 1) and experience in fabricating thin film devices. Solid state sensors utilized by other workers (Refs. 2, 3, 4, 5, 6) have included metal and semiconductor films and crystals of materials like carbon and aluminum oxide for the measurement of water vapor in the air and have relied upon measuring resistance and capacitance changes in the sensor in response to adsorbed vapors or gases. Since the effect of carbon monoxide in changing the resistance of various materials such as molybdenum, platinum, and zinc oxide had been reported (Refs. 7, 8, 9, 10), the requirements appeared to be realisable, although it was recognized even at the inception of the work that specificity to carbon monoxide might require the incorporation of more than one sensor.

Jan 1, 1976

By C. R. Hubbard

The Bureau of Mines investigated the mineral resources of the Upper Missouri River Basin as a part of a comprehensive water and related land resources study by six Bureaus of the Department of the Interior, coordinated by the Department's Missouri River Basin Field Committee. The mineral resource study covers an area of about 18,000 square miles within the Great Plains physiographic province of central Montana. Exposed Formations in the plains are chiefly flat-lying Cretaceous sediments. Plutonic rocks crop out in the central parts of the mountain uplifts, with steeply tilted Paleozoic sediments exposed around the margins. Oil and gas have been produced from several fields in the study area; total value exceeds $45 million. Coal-bearing formations of Upper Jurassic and Cretaceous age cover approximately 45 percent of the study area. Total production of coal since 1880 has been between 40 and 50 million tons, exceeding $75 million in value. Total metal production has been about $52.5 million. Industrial mineral production from 1925 through 1960, is valued at $24 million.

Jan 1, 1964

By C. R. Hubbard

The Bureau of Mines investigated the mineral resources of the Upper Missouri River Basin as a part of a comprehensive water and related land resources study by six Bureaus of the Department of the Interior, coordinated by the Department?s Missouri River Basin Field Committee. The mineral resource study covers an area of about 18,000 square miles within the Great Plains physiographic province of central Montana. Exposed formations in the plains are chiefly flat-lying Cretaceous sediments. Plutonic rocks crop out in the central parts of the mountain uplifts, with steeply tilted Paleozoic sediments exposed around the margins. Oil and gas have been produced from several fields in the study area; total value exceeds $45 million. Coal-bearing formations of Upper Jurassic and Cretaceous age cover approximately 45 percent of the study area. Total production of coal since 1880 has been between 40 and 50 million tons, exceeding $75 million in value. Total metal production has been about $52.5 million. Industrial mineral production from 1925 through 1960, is valued at $24 million.

Jan 1, 1964

By W. W. Adams, T. D. Lawrence

"A. larger enrollment and a greater number of man-hours of employment by the enrolled companies were the outstanding features of the National Safety Competition of 1942, an annual safety contest conducted by the Bureau of Mines, United States Department of the Interior, for the promotion of safety among workers in the mines and quarries of the United States. The accident-frequency and accident-severity rates were somewhat higher than in 1941, but the frequency of accidents in relation to the number of man-hours worked was strikingly lower than in the earlier years of the 18-year period during which the contests have been conducted.Companies that enroll in the National Safety Competition compete for a bronze trophy known as the ""Sentinels of Safety."" Six of these trophies are provided by THE EXPLOSIVES ENGINEER annually for award by the Bureau of Mines. The trophies for 1942 wore won by an anthracite mine in Pennsylvania, a lignite mine in North Dakota, an underground metal mine in Tennessee, a limestone mine in Ohio, an open-cut metal mine in Minnesota, and a lime-:tone quarry in Pennsylvania. The trophies are presented to the companies for 1 year and are then transferred to the winners of the succeeding year's contest.The contest rules state that a mine or quarry must have at least 25 men employed underground or in the pit for at least 100 days, and the plant must be in operation 30,000 or more man-hours to be eligible for a trophy. The rank of mines and quarries is determined by accident-severity rates, or, in the case of accident-free records, by the number of man-hours worked."

Oct 1, 1943

By A. Erickson

The effectiveness of a loader-mounted fan on diesel vehicles combined with natural convection for ventilation of a dead heading (the patented Janelid system) was investigated experimentally. The results were obtained using CO2 as a tracer gas in a 1/4 scale model heading. Buoyant forces were scaled to establish similarity with full scale. For a loader moving in a typical load-haul-dump cycle, the loader-mounted fan reduced the tracer gas concentration by 26 percent compared with a reduction of 32 percent for a jet fan of four times the flow capacity.

Jan 1, 1981

By Bernard Porter, E. A. Brown

Electrical conductivities and densities of the LiF- UF , LiF- ThF4 , NaF - C1F4 , and NaF - ThF systems were measured as functions of composition and temperature . The specific conductance and density varied linearly with temperature . Molar and equivalent volumes , as well as heats of activation for conductance , were calculated from the experimental data . At 1,000 ° C , the molar volumes ranged from 16 to 40 cubic centimeters per mole and the specific conductance ranged from 9.8 to 2.5 per ohm- centimeter as the actinide metal fluoride concentration changed from 0 to 60 mole - percent . Heats of activation for conductance were 3 to 7 kcal per mole . The data are interpreted on the basis of a semilattice model for the melts .

Jan 1, 1964

By Eugene T. Sheridan

The process of converting coal into coke is known as carbonization. Essentially, carbonization is destructive distillation in which the volatile matter of coal is released when coal is heated above its decomposition temperature and passes through a plastic stage before solidifying and forming coke. The mechanics of coke formation are complex, and the specific properties of certain coals that allow them to "cake" or form coke are still unknown. Coke is a hard, cellular, carbonaceous mass, formed by heating coal in the absence of air. It is porous, irregular in size and shape, and is similar in appearance to wood charcoal. Coke, however, is denser, more porous, and more abrasive than charcoal.

Jan 1, 1965

By Marvin W. Wilson

The Federal Bureau of Mines has conducted laboratory experiments simulating underground gasification of coal to study the feasibility and mechanism of the process and determine the chemical and physical characteristics of a coal-bed during gasification. Laboratory and small-scale field experiments also were made to investigate the properties of coal and other factors affecting the electrolinking-carbonization method of preparing a path through a coalbed before gasification. Laboratory experiments simulating underground gasification of coal: Experiments with a laboratory retort indicated that bituminous-coal deposits could be gasified in place to produce a combustible gas.

Jan 1, 1960

By Eugene T. Sheridan

The process of converting coal into coke is known as carbonization. Essentially, carbonization is destructive distillation in which the volatile matter of coal is released when coal is he ted above its decomposition temperature and passes through a plastic stage before solidifying and forming coke. The mechanics of coke formation are complex, and the specific properties of certain coals that tallow them to "cake" or form coke are still unknown. Coke is a hard, cellular, carbonaceous mass, formed by heating coal in the absence of air. It is porous, irregular in size and shape, and is similar in appearance to wood charcoal. Coke, however, is denser, more porous, and more abrasive than charcoal.

Jan 1, 1965

In 2007, a total of 725 nonmetal mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 Nonmetal mines com-prised 4.9% of all m ining operations. ? Mines producing common clay comprised 25.4% (n=184) of all nonmetal mining operations. ? Nonmetal mining operations were located in all states and territories except Alaska, Delaware, Hawaii, Maine, New Hampshire, Rhode Island, Puerto Rico, and the U.S. Virgin Islands.

Aug 1, 2009

By Wallace W. Key

The California pesticide industry in 1962 consumed about 30,000 tons of clay, talc, limestone, diatomite, sulfur, and other minerals as fillers (carriers and diluents) in pesticide formulation. This was 10 percent of the U.S. filler requirement for pesticides. About two-thirds of the California total was supplied by a few local mineral producers; the remainder came mainly from Florida, Georgia, and Wyoming. The objectives of this report are to provide data on quantities, sources, specifications, and market conditions for minerals used as fillers by California pesticide formulators. The study disclosed that specifications for mineral fillers have become more rigid and formulators have become more numerous in recent years. During 1962 over 1,200 firms registered 16,000 pesticide products with the Bureau of Chemistry in California. Factors which will tend to diminish future need for mineral fillers include the trend toward greater use of organic sprays rather than dusts and further development of biological controls, such as the development of sterile insect strains.

Jan 1, 1965

By J. C. Duchon

The use of extended workdays or compressed workweeks (regular shift lengths exceeding 8 h) is attracting growing interest in many industries using continuous operations. While extended workdays promise increased worker satisfaction due to more days off, including weekends and holidays, there are legitimate concerns about the potential effects on the health and safety of such a schedule. The U.S. Bureau of Mines (USBM) conducted a study at a Canadian underground copper, lead, and zinc mining operation that was designed to study the safety and performance implications of extended workdays. Measures were taken before and after a change from the old 8-h continuous schedule to the new 12-h continuous schedule, including behavioral performance measures to analyze perceptual-motor changes, continuous heart-rate monitoring and aerobic capacity to measure physical fatigue, a variety of self-report questionnaires to measure perceived adaption and satisfaction with the new schedule, and pulmonary-respiratory measures to examine air contaminant exposure. Based upon the overall acceptance of the new schedule by the workers and lack of change in fatigue-sensitive behavioral and physiological performance measures, this study recommends that the mine retain the 12-h schedule. However, certain precautionary measures are suggested to insure the safety of the workers.

Jan 1, 2010

By Wallace W. Key

The California pesticide industry in 1962 consumed about 30,000 tons of clay, talc, limestone, diatomite, sulfur, and other minerals as fillers (carriers and diluents) in pesticide formulation. This was 10 percent of the U.S. filler requirement for pesticides. About two- thirds of the California total was supplied by a few local mineral producers; the remainder came mainly from Florida, Georgia, and Wyoming. The objectives of this report are to provide data on quantities, sources, specifications, and market conditions for minerals used as fillers by California pesticide formulators. The study disclosed that specifications for mineral fillers have become more rigid and formulators have become more numerous in recent years. During 1962 over 1,200 firms registered 16,000 pesticide products with the Bureau of Chemistry in California. Factors which will tend to diminish future need for mineral fillers include the trend toward greater use of organic sprays rather than dusts and further development of biological controls, such as the development of sterile insect strains.

Jan 1, 1965

By John E. McCullough

The purpose of this development program is to design and develop a known volume air sampling pump for use in measuring the amount of radio-active material in the atmosphere of an underground uranium mine. The principle nuclear radiation hazard to underground uranium mines comes from the mine atmosphere. Daughter products of 222-radon, namely 214-polonium, 214-lead, 214-bismuth and 214-polonium, are inhaled by the miner, resulting in a relatively high lung cancer rate among these workers.

Jan 1, 1976