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By J. B. Gayle

The Bureau of Mines sole-heated oven has been used for studying coal expansion for some 20 years. During the period before 1940 emphasis was placed on studies of the mechanism of coal expansion and the effects of variations in operating conditions on the results. Since 1940 emphasis has shifted to a survey of the expansion properties of various coking coals. Because additional information concerning a number of unsolved problems in connection with the earlier studies appeared highly desirable, this investigation of the use of sole-heated ovens for studying coal expansion was undertaken. The principal findings, in order of their discussion in the text, may be summarized as follows. 1. Expansion results for binary blends of coking coals exhibit nonadditive behavior, both positive and negative deviations from additive behavior being noted, depending on the particular coals tested. Additive behavior can be achieved, however, either by charging the blend components in separate layers (which indicates that the observed phenomena are not characteristic of the particular expansion oven used) or by testing relatively coarse sizes of coal (which suggests that the effects of crushing on the expansion properties of coking coals may be even more complex than is generally recognized).

Jan 1, 1959

By J. D. Sargent

Selenium might be described as a paradoxical element, being a metal or a nonmetal, a conductor or nonconductor, amorphous or crystalline, colorant or decolorant, and a hydrogenator or dehydrogenator. Selenium was discovered in 1817 by the Swedish chemist, Berzelius, while studying flue dust from the lead chambers of the sulfuric acid works at Gripsholm, Sweden.

Jan 1, 1954

By J. E. Tiffany, Z. C. Gaugler

"In presenting this list of permissible explosives and blasting devices, the Bureau of Mines desires to call attention to pages 20 and 25 outlining the conditions in use under which, and only under which, the explosive or blasting device is permissible.In view of a recent publication recounting trade practice favoring the use of a blasting device without stemming, particular emphasis is placed upon condition 4 on page 20 and condition 2 on page 25. An explosive or a blasting device enumerated in the permissible lists of this Bureau is not permissible in use unless it is properly confined with clay or other incombustible stemming.PERMISSIBLE EXPLOSIVES TESTED UNDER SCHEDULE 17CAn active list of permissible explosives was published in October 1938 as part of Bureau of Mines Report of Investigations 3421, under the title ""Active List of Permissible Explosives and. Blasting Devices Approved Prior to June 30, 1938."" This list included 191 brand names.Changes in the list that have been authorized to June 30, 1939, placed 56 additional brands of permissible explosives on the active permissible list as a result of tests, changes in brand names, or transfer from the inactive list. Fifty-seven permissible explosives were transferred from the active to the inactive list. The brand names of four explosives were rescinded curing the year. The present list contains 18G brand names. The brand names of the Permissible explosives placed on the active list are as follows:"

Sep 1, 1939

The Mine Safety and Health Administration (MSHA) defines an independent contractor as "any person, partnership, corporation, subsidiary of a corporation, firm, association or other organization that contracts to perform services or construction at a mine." Contractors that perform specific types of work are required to report the number of employees who perform work at coal mines and at noncoal mines.

Jan 1, 2004

1. In 2002, a total of 7,125 sand and gravel mining operations reported employment to the Mine Safety and Health Administration (MSHA). The largest percentage of all mining sectors1 was sand and gravel mines (49.1%). Sand and gravel mines are found throughout all 50 states.

Jan 1, 2004

By Ralph L. Rinehart, Wils L. Cooley

This paper summarizes recent experiments with grounding systems. Problems and potential hazards related to in-mine grounding systems are discussed. The monitoring of trailing cable ground conductors and testing of commercially available ground monitors are discussed.

Jan 1, 1975

By Joseph Chalmers

Stimulative methods of production, whereby the total recovery of oil from natural reservoirs is increased, have come into considerable prominence during the past 15 years. In many oil-producing areas properties considered ready for abandonment by ordinary producing methods have responded to some form of stimulation, and their economic lives have been extended. The stimulative method having widest application is the injection of air or gas into the reservoir formations through selected input wells and is commonly referred to as the "gas drive." As a result of the many successful "gas-drive" operations operators are depending more and more upon this method for increasing the ultimate recovery of oil from their properties. A number of factors influence the efficacy of different gases as propulsive agents in recovering oil from sands. Gases of high density and viscosity show a tendency toward a slightly higher efficiency than those of lower density and viscosity. The solubility of the gas in the oil also affects the efficiency of oil recovery. Not only does dissolved gas decrease the viscosity of the oil, but dissolved gas that expands from solution in the oil tends to increase the effectiveness of a "gas drive." Interfacial tension between the oil and the gas and its effect upon the recovery of oil by gas injection are factors of which little is known. Dr. A. G. Loomis expressed the opinion that interfacial tension probably plays a minor role in the recovery of oil, except under conditions that produce a gas-oil foam. In connection with the above physical properties that influence the action of a pressure medium, control of the injected volume of the pressure medium is perhaps the major factor. The rate of gas injection determines to a great extent the amount of slippage and the resulting efficiency of the operation. The importance of volume control is realized when one considers that frequently it is the only factor that is under complete control of the operator.

Jan 1, 1930

By William M. Nabors

As a part of a program to promote conservation and efficient utilization of petroleum resources, Bureau of Mines engineers are studying secondary oil-recovery projects in the United States. Published reports that set forth the pertinent facts of these operations help others to profit by the experience gained. This report presents the results of a study of secondary-recovery methods used in Kentucky by the Cumberland Petroleum Co. on its L. C. Bailey lease, Oil Springs pool, Magoffin County, Ky. This is believed to be the first water-flooding project in eastern Kentucky (fig. 1).

Jan 1, 1958

By R. E. Mussler

As part of an overall goal to develop technology that can maintain an adequate supply of minerals to meet national economic and strategic needs, the Bureau of Mines is evaluating a method for selectively extracting nickel and cobalt from low-grade domestic laterites. The method involves electrowinning to recover the metals in pure form; therefore, preliminary laboratory-scale electrowinning tests were conducted in both a nondiaphragm and a diaphragm cell to determine the effect of variables on energy efficiency under controlled conditions. Electrolytes were generally reagent-grade sulfate solutions that were prepared to simulate electrolyte that could be obtained by stripping nickel-and cobalt-rich solvent extraction reagents. Limited tests were conducted with electrolyte generated from laterite leach solutions. Electrical energy consumption in a nondiaphragm cell was 2.06 kwhr/lb Ni with the cell operated at 50° C, a cell feed of 90 g/l Ni, a pH of 3.5, an extraction of 3.2 g/l, and a cathode current density of 20 amp/ft2. The energy requirement decreased with increasing concentration and temperature, and increased with increasing. extraction and current density. At 50° C, energy consumption in the nondiaphragm cell was 21 pct greater than in the diaphragm cell, but it was only 5 pet greater at 65° C. For this reason and because of overall cost considerations, operation at 65° C with the nondiaphragm cell was preferred. Smooth sheets of cobalt were obtained by electrowinning in a nondiaphragm cell at selected temperatures from 50° to 85° C and with cobalt concentrations from 55 to 87 g/l. The energy consumption (1.48 kwhr/lb) was 22 pet lower with a cobalt concentration of 75 g/l and a cell temperature of 65° C than with a cobalt concentration of 55 g/l and a cell temperature of 50° C.

Jan 1, 1981

By Joseph Cervik

Gas occurs in coalbeds in an adsorbed and a free gas state. Adsorbed gas is stored in the micropore structure and its transport is governed by Fick's law. The free gas occurs in the fracture system and flows according to Darcy's law. These two modes of mass transport are interdependent. Production decline curves of coal-gas wells are of the constant percentage decline type and, thus, show no indications of flow characteristics peculiar to coal-gas reservoirs. The effectiveness of surface boreholes as a degasification scheme depends upon both good fracture permeability and a high fracture density. Conventional methods of reservoir engineering analysis are not applicable to coalbeds

May 1, 1969

By Ralph L. Brown

"IntroductionThe accumulation of gummy and resinous deposits in consumers' gas meters began to assume serious proportions about 1917. As the trouble developed and spread in the years following, it manifested itself in several ways, which ultimately began to the expressible in distinctly economic terms, more specifically in terms of costs; in 1922 an organized and fundamentally based investigation of this trouble was begun. In an earlier paper*** a short statement of the occurrence and costs of the deposition was given and at the same time an analysis of the problem, as well as well as a general plan of attack, was presented. That plan included two general phases, first, a chemical study of typical was 1 quarry or 2 cosinous content , mauformly consituents, rmln and selected subjects; and secondly, a comparative survey of plants affected and sufficient therewith, attention being paid to construction, operation, meter conditions and related data. In reporting progress in the axtual investigation, it was definitely set down that the basis of the gummy deposits was the unsaturated hydro consulting from the carburxtion of the water-gas with oil. That the presence of oily-gas condensate was closely associated with and largely"

Jul 1, 1923

By F. N. Kissell, C. D. Litton

This study ranks the factors impacting survival during a coal mine fire. It bas already been established that reducing time delays is the most important factor in saving lives. Consequently every event during afire is measured in terms d its duration, and the effectiveness d any action taken to improve survival is measured in terms d the time it saves. By ranking actions according to time saved these authors found that a comhination d actions was most effective. This combination was: • installing lifelines. • moderately decreasing air leakage and • decreasing the fire growth rate. Changing ventilation leakage alone was much less effective, as was altering the CO (carbon monoxide), sensor alarm threshold. These results confirm an earlier fault-tree study on escape from mine fires. The fault-tree study bad shown that, with the exception d delays, single factor changes have minimal impact. Significant reductions in fire fatalities only take place with multiple factor changes.

By Thomas J. Peters

In 1988, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 5,640-acre Soda Mountain Wilderness Study Area (OR-011-017), in order to evaluate its identified mineral resources. The study area is located in Jackson County, OR, about 30 miles south-east of Medford. The study area covers most of the south-facing slope of 6,071-ft Soda Mountain. Geologically, the area is underlain by Oligocene to Pliocene basaltic andesite flows and less extensive intrusive rocks of the western Cascade Mountains. In addition, there is a 3/4-mile-diameter area of kaolinized and silicified rhyolite tuff, which appears to have intruded the andesite, and is host to epithermal gold mineralization.

Jan 1, 1989

By H. V. Makar

Ferrous fractions recovered from urban refuse were tested by the U.S. Bureau of Mines, U.S. Department of the Interior, to assess their character, composition, and response to detinning. This research was conducted as part of the Bureau's efforts to conserve mineral resources through recycling. Results from laboratory and pilot tests established the technical feasibility of detinning scrap recovered from household refuse. Detinned products containing less than 0.03 percent residual tin were produced. Concentrations of other residual elements were determined and compared with those in existing commercial scrap and with proposed specifications. Studies were extended to include evaluations under commercial conditions. Preliminary tests on 5-1/2 short tons of ferrous fractions revealed the need for adequate shredding to assure optimum metal-caustic contact and minimize retention of tin-bearing rinse solution in the final baled product. The washed metal product contained 0.06 percent residual tin. Subsequent melt tests showed a yield of 91.4 percent. Based on these studies, full-scale commercial demonstrations showed that detinned bales equivalent to No. 1 bundle quality could be produced in carload quantities. Up to 5 pounds of tin per gross ton of scrap is con-currently recovered during the detinning process.

Jan 1, 1979

By C. M. K. Boldt

This report summarizes five separate Bureau of Mines contract studies on the use of aerial photogrammetry, satellite transmission of in situ instrumentation information, and satellite imagery to monitor and update mine waste embankment data. The equipment used, methods applied, results, recommendations, and cost analyses are presented along with a bibliography of related investigations.

Jan 1, 1987

By Paul S. Lewis

Bench-scale experiment~ by the Bureau of Mines showed the gross effect of retention times ranging from 0.1 to 14.5 minutes on the conversion of high-volatile C bituminous coal to liquids and gases. The uncatalyzed coal was hydrogenated at 400°, 450°, and 538° C. and 500, 1,000, and 2,000 p.s.i.g. The percent coal conversion increased rapidly during the initial 3 minutes and asymptotically approached a maximum within 7 minutes at all conditions. Reasonably good correlations of coal conversion with time, pressure, and temperature were obtained. Temperatures up to 900° C. and retention times of about 1 minute are recommended for future experiments with the objective of producing only gaseous hydrocarbons and partially devolatilized coal suitable for use as solid fuel. The reactor contained 13 semicircular ledges, and the retention time was controlled by the rotation of scrapers which swept the coal from ledge to ledge. Only coal feeds that did not adhere to the internal mechanism could be used.

Jan 1, 1961

By Charles L. Kimbell

The concept of data availability must be addressed, because there are perceptible changes from year to year, and the availability of accurately reported, precisely defined statistics and nonstatistical information provides the only sound basis for analytical studies required for government policy planning or industry market analysis. As the countries of Eastern Europe and the former U.S.S.R. undergo the transition from centrally planned economies to market economies, there has been a perceptible increase in information availability for rather obvious reasons. Any industrial operation seeking economic assistance from Government and/or private sources outside the country in which the facility is sited must provide some appraisal of its operations at the time it seeks assistance, as well as some information on previous performance to serve as tools in evaluating its potential under the proposed development scheme for which it seeks financial assistance. Additionally, there was growing governmental recognition that concealment of much of the national mineral production, trade, and consumption data for purposes of national military and/or economic security probably never was very successful, never was really necessary for most commodities, and certainly proved unnecessary with the end of the so-called cold war. Indeed, the long-term unwillingness to publish uniform statistical series of reliable,

Jan 1, 1993

By Michael D. Fenton

Detailed comprehensive assessment of the performance of Afghanistan's mineral industry during 1987 is virtually impossible, owing to the paucity of reliable published information. It was evident, however, that the level of civil disorder, now in its eighth year since the arrival of significant numbers of Soviet troops, was in actuality little removed from open civil war. Insurgents controlled substantial areas of the country and imperiled any industrial activity in many places. Assistance programs by the U.S.S.R. and other Eastern European nations were directed at developing the country's meager mineral industry, but the economy was generally viewed as chaotic. The inflation rate was somewhere between 20% and 30%; major food shortages contributed to the discontent of the population, and numerous villages were devastated by Soviet and Afghan Government campaigns to destroy the insurgents and cut their supply routes. Moreover, proposals by the Soviets and the Kabul Government aimed at reducing tensions with the rebels and scaling down the warfare seemingly were taken by the opposition as signs of weakening by the Soviet-backed Government, and rather than reducing aggressions, seemed to heighten insurrectionist activities. Efforts to entice the substantial number of Afghans who have fled to nearby areas of Pakistan and Iran to return to their country seemingly were failures, and indications near yearend that the Soviet Union might soon begin withdrawal of its occupation force of nearly 120,000 did little if any to reduce disorder.

Jan 1, 1989

Develop a training program to help mine workers effectively fight small fires in underground Goal mines. Training would enable miners to make rapid judgments on whether to attempt extinguishment, and how best to use the firefighting equipment on hand. Approach Fire reports were analyzed to define and delineate physical and behavioral variables which affect firefighting activities, and to determine effective procedures for extinguishing small fires. A course was then designed to train miners in such procedures. Finally, the course was reviewed by industry experts and administered to a group of miners to determine needed revisions and to validate the course. How It Works Analysis of fire data showed that six items should be emphasized in teaching proper fire response: 1. Alertness to fire potential. 2. Immediate power cutoff. 3. Internal, external communication. 4. Teamwork in fighting fires. 5. Role of ventilation and position of men inby the fresh air side. 6. Effective use of fire suppressant materials.

Jan 1, 1983

By C. C. Clark, R. R. Backer, J. D. Vickery

This report presents the results of tests conducted by the U.S. Bureau of Mines to determine the transport characteristics of highly concentrated paste backfill mixes made from dewatered total mine tailings. The slurry concentrations of the mixes were all above 78 pct by weight with slumps ranging from 6.4 to 16.5 cm (2.5 to 6.5in). Laboratory material property tests and full-scale pumping tests were conducted using pipe diameters of 102,128, and 154 mm (4, 5, and 6 in) and a positive-displacement pump. The results indicated that the tested backfill mixes can be successfully transported as a stiff paste and identified the influence of and the interaction among the various mix and system variables.

Jan 1, 1995