Search Documents

By George R. Schottler

The Bureau of Mines investigated the distribution of uranium and various methods of ore sampling in a uranium deposit typical of those in the Morrison Formation sandstone of the Ambrosia Lake area, Grants mining district, north-western New Mexico. Chemical and radiometric assays of diamond-drill core samples are compared in detail by statistical techniques, and the assay data are correlated with the stratigraphy of the deposit. Conclusions applicable to ore-reserve estimation in geologically similar uranium deposits are drawn.

Jan 1, 1971

By William A. Vogely

STRIKES in the steel and copper industries adversely affected production in the minerals industry in 1959. Because of an excellent first half of the year and rapid recovery of production after the steel settlement, most statistical indicators were higher than the recession-recovery year 1958. Domestic production of metals declined by 9 percent, but nonmetals (except fuels) increased by 8 percent. Ferrous-metal mine production was down 8 percent, and base-metal mine production was off 11 percent. Employment was high during the first half of the year, but averaged lower than in 1958. Stocks continued to decline as a whole, but crude metal ore stocks actually increased. The indexes of stocks at yearend were still high as compared with 1955. Prices were firm throughout the year. A new index of average unit mine value is presented for the first time in this review; it showed a very slight decline in average mine realization for 1959. The percentage share of supply from imports increased in some commodities, due in large part to the shutdown of domestic iron, steel, and copper industries.

Jan 1, 1960

By John C. Franklin

The Bureau of Mines conducted extensive laboratory and limited field tests to determine whether a polymeric material could effectively reduce the emanation rate of radon gas from uranium ore. In the laboratory 46 different single-coat materials and 14 two-coat applications were tested. The laboratory tests showed that up to 100 percent of the radon gas could be sealed into the rock. Materials tested in the laboratory were polyesters, furan resins, epoxies, latices, and totally inorganic coatings. From the laboratory work six different materials were selected for field testing. The first test was single-coat materials in five static chambers; the second test used two-coat applications in an open chamber. Both tests were conducted in the Dakota mine at Grants, N. Mex. During the second test, the amanation rate of radon gas was reduced up to 62 percent.

Jan 1, 1975

By Wesley A. Grosh

The Allah Cooper mine, in Louisa County, Va., formerly was a producer of lead and zinc. It was believed that the critical shortage of leach and zinc and the fact that some ore had been produced at this mine justified exploration of it. A preliminary examination was made on April 30, 1943, by J. E. Hill, a Bureau of Mines Engineer. Diamond drilling was done on the property from November 30 to December 18, 1943, to determine whether the sulfide body extended to depth. One hole drilled to a depth of 650 feet and located so as to cut the Allah Cooper ore shoot about 150 feet below the lowest known mine workings failed to disclose sulfide vein at that depth.

Jan 1, 1949

By Linda L. Chasko, Charles P. Lazzara, Ronald S. (deceased) Conti, William J. Wiehagen

Fire has long been a concern for underground mine workers. A mine fire can occur at any time and can result in a partial or total evacuation of mine personnel and the loss of lives. Fires can grow rapidly. Time is the critical element. Prompt detection, timely and accurate warnings to those potentially affected, and a proficient response by underground miners can have a tremendous impact on the social and economic consequence of a small underground fire. Fire preparedness and response have components of technology and people. These components can work synergistically to reduce the time it takes to bring the system back in balance. This report deals with the preparedness of miners to respond to underground mine fires. It is intended to aid the mining industry in understanding the various roles of emergency responders and the training techniques used to increase their skill levels. The report also presents a technology overview to assist in effective response to mine fires.

Jan 12, 2005

By W. E. Robinson

Sixty samples, selected from a 2,300-foot core of the Green River Formation in Colorado, were studied to ascertain differences in the structure of the organic material present in the oil shale samples. Emphasis was placed upon relating differences in the aromatic content of the insoluble kerogen and the alkane content of the extractable material obtained from the selected samples. The methods used in determining these differences consisted of fractionation of the soluble material, carbon and hydrogen analysis, volatile material determination, carbon residue determination, oxidation rate determination, and infrared analysis. In general, it was concluded that the organic material in this core does vary in chemical structure and that same of these variations resulted from factors related to depth of burial. Other observed changes in structure of the organic material were not depth-dependent and resulted from other factors such as source material variations, biological alterations, or ecological differences.

Jan 1, 1971

By Charles Anema

The Mancarried and Helicopter Receivers were developed under the contract I for trapped miner location. This program was a five phase program with 15 mancarried and 5 helicopter production receivers delivered under Phase IV and equipment documentation required under Phase V.

Jan 11, 1976

By D. B. Dow

This report on methods employed for dehydrating oil-field emulsions, is the second of a series prepared as a result of a study of oil-field emulsions recently completed by the writer. The first paper2 dealt with the factors responsible for the formation of emulsions. A third paper will discuss the physical chemistry involved in the formation and resolution of such emulsions. In the early development of the oil fields of Pennsylvania, no emulsion troubles of any consequence were encountered, nor to any serious extent in the oil fields of other Eastern States: However, with the development of fields west of the Mississippi in Oklahoma, Kansas, Texas and California, where heavier oils of different characteristics were found, the problem of dealing with cut oil soon became of great importance.

Jan 1, 1925

By W. A. Calhoun

The purpose of this investigation was to develop a procedure for removing excess iron from representative samples of bauxite ore from the Quapaw deposit of American Cyanamid Co., Saline County, Ark., in order to produce a beneficiated ore suitable for use in the alum industry, At the request of the sponsoring company, the samples were reduction-roasted at 800° C. and then magnetically separated. Although some rejection of iron was effected under these conditions, the general results were not satisfactory, A much more successful procedure, from the standpoints of both rejection of iron and recovery of alumina, consisted of a short (l5-minute), low-temperature (400° C.) oxidizing roast, followed by a 2-minute interval in a hydrogen atmosphere, then cooling to room temperature, and, finally, high-intensity magnetic separation to remove the iron.

Jan 1, 1957

By Dennis R. Dolinar, Eric R. Bauer

Skin failures of roof and rib in underground coal mines continue to be a significant safety hazard for mineworkers. Skin failures do not usually involve failure of the support systems, but result from rock or coal spalling from between the support elements. For instance, in 1997 more than 800 miners were injured by roof and rib falls, of which 98% were the result of skin failures [Bauer et al. 1999]. Also, nearly 80% of the roof and rib failure injuries occurred at or near the working faces in development sections. The face area is a zone where the potential for skin failure accidents and injuries and for roof and rib failures is high because of mining activity, ground readjustment due to changing stress conditions, and the higher exposure of mine workers. In addition, failures occur where the roof and rib are unsupported. This paper reviews the roof and rib accident statistics resulting from skin failure, and highlights the incidences by type, numbers and percentage, in-mine location, supported and unsupported roof, and worker activity at the time of injury. Also discussed are the causes of roof and rib skin failures, current and improved support methods and materials for skin surface control, and machine design modifications for improved roof bolter operator protection. It also reviews the historical literature on skin failures and control methods.

Jan 10, 2000

By L. W. Higley

Particulates generated in electric furnace (EF) steelmaking constitute approximately 1 to 2 pct of the charge. This flue dust is a rich source of zinc (values are substantially higher than in ore), but although there are several processes for recovering the metal, none are considered economic in the United States. This report reviews extraction technology and presents results of Bureau of Mines reduction-volatilization tests on pelletized EF dusts which achieved high recoveries of zinc. The data are sufficiently encouraging to warrant consideration of EF dusts as raw material for primary zinc smelters.

Jan 1, 1977

By Robert P. Vinson

A sequential sampler, based on the Archimedes screw, has been developed by the Bureau of Mines. Its initial purpose was to collect air samples during tracer gas studies in underground mines. However, the basic concept can be applied to other sampling needs, including sampling of liquids. A prototype was built and successfully tested in the Bureau's Experimental Mine at Bruceton, Pa. The simple design makes the sampler inherently durable and low in cost.

Jan 1, 1976

By G. M. Molinda, J. P. Ulery

Since 1970, abnormally high methane emissions have been observed in eastern sections of the Federal No. 2 Mine operating in the Pittsburgh Coalbed in northern West Virginia. The nature and volume of these emissions indicate a source other than the coalbed. An investigation was undertaken to delineate probable methane sources. Gas well information and stratigraphic correlation of corehole data indicates that a sandstone directly above the main coalbed is an additional source of methane emissions. The sandstone body appears to be an ancient stream channel, infilled with fine-grained sand and organic matter. Coalification of the organic matter produced methane as a byproduct. Additional methane presumably migrated into the sandstone unit from the subjacent coalbeds. The methane became trapped in the porous clasticunit by the surrounding impermeable strata. Mine development near this unit creates a significant pressure gradient, triggering abnormal methane emissions into the mine along naturally occurring fractures. Pre-development methane drainage of the sandstone could be accomplished by completing vertical boreholes along its trend.

Jan 1, 1984

By R. L. Anderson

Mechanical cleaning of bituminous coal in the United States was begun about 1875, with plants in western Pennsylvania and Illinois. The United States Geological Survey began to record the quantity of washed bituminous coal in 1906; and the series was carried forward to 1923, except that no data were collected, for 1922. This statistical work was transferred to the Bureau of Mines in 1925, and the collection of data on mechanical cleaning was resumed in 1927. Data collected before 1927 include only the coal that was washed at the mines and do not include that cleaned by pneumatic methods at the mines and that cleaned at central washeries operated by consumers.2/ The total bituminous coal washed in 1906 was less than 10 million net tons. In 1927, the first year for which complete figures are available for all types of mechanical cleaning, 28 million net tons of bituminous coal were cleaned in the United States.

Jan 1, 1951

Large quantities of combustible materials are often found in underground metal and nonmetal mines, with support timber predominating. Wood lagging and timber, wires and cables, brattice cloth, hose, paper products, cardboard cartons, and wooden containers are additional combustible materials commonly found in underground storage areas. Shorted or overloaded electrical cables, worn sockets and plugs, spontaneous combustion, careless smoking, and welding and cutting are common fire ignition sources. Inexpensive, reliable fire detection and suppression systems are available to provide early warning and to extinguish fires that originate in underground storage areas.

Jan 1, 2011

By Edward L. McHugh

Digital camera and computer technologies can be used to monitor mine slopes and provide real-time warning of rock falls. NIOSH researchers assembled a surveillance system using low-cost video cameras and computer software from the security industry to test its effectiveness. The system is designed to signal an alarm when motion is detected and to record images of the scene. Masking can restrict motion detection to specific areas within the camera view; sensitivity is adjustable. The time-stamped images provide a record that can help reconstruct and quantify an event. Video motion detection can augment standard monitoring methods to increase safety in surface mines.

By Harold L. Rhodes

Vapor-liquid equilibria data for 65-34-1 and 25-27-48 mole percent helium-nitrogen-methane mixtures are presented for 12 temperatures from 76.5° to 164° K and pressures from 100 to 1,200 psia. These data were obtained in a windowed phase equilibria cell equipped with a vapor recirculating pump. Isobaric and isothermal K-values are plotted for both mixtures. Two isometric plots are included.

Jan 1, 1972

Although haulage truck collisions account for only a small percentage of haulage accidents, the likelihood of severe injury, or even death is very high when such a collision does occur. Most rear-end collisions also result in considerable equipment damage, creating a need for expensive repairs. To improve collision protection, some southwestern surface mines have, for several years, been fabricating and using extended bumpers. In cooperation with these mines, the Bureau of Mines has worked to improve this technology by evaluating the structural requiremnts of extended bumpers. How Extended Bumpers Help The Bureau found that when one large rear-dump haulage truck collides with the rear of another an extended bumper protects the driver of the vehicle that is struck by dissipating the impact energy into the rear tires and pushing the whole vehicle forward. An extended bumper also prevents the box on the truck that is hit from penetrating the cab of the other truck-a typical and serious collision hazard. A further advantage derives from the wide design of the extended bumper which helps prevent damage to truck ladders, thereby minimizing any entry or exit problems. Extended bumpers also provide safe work platforms at the front of large haulage vehicles.

Jan 1, 1984

By E. D. Gardner

"The Bureau of Mines has studied blasting practices in metal mines of the Southwest. The investigation of blasting drift rounds showed among other results, that cut-holes in ground difficult to break could be chambered to advantage under some conditions.In open--cut mines, chambering nearly all holes before blasting is the common practice. Two or more free faces are generally maintained in this type of work, and the amount of explosive necessary to break any bench or bank can usually be estimated from the yardage to be moved. However, in blasting drift or tunnel rounds only one free face is available before the cut-holes are shot, and the quantity of explosive required is generally ascertained best by trial.In addition to being the most difficult to break, the cut-holes are the most important of a drift round. When the cut-holes ""break bottom"" less work is required of the other holes, and a full break of the round is generally obtained. In ground difficult to blast, extra care and expense are justified to insure that the cut-holes ""break bottom.""At many mines the work is so organized that all blasting is done at the end of the shift, and a decided advantage would have to be gained to make chambering of the cut-holes economical. Also, in many mines blasting during the shift would not be practical. One or two holes could probably be drilled during the time necessary to do the chambering. However, under certain special conditions, such as in small operations or those where ""leasers"" or contractors are working, drill holes could be chambered should there be an advantage in doing so. Moreover, in some mines it might be practical to chamber the cut-holes at the lunch hour. In ordinary rounds the cut-holes are generally drilled by noon. It would not be necessary to tear down the drill or remove tools from the face to do this work of chambering."

Feb 1, 1928

By R. L. Montgomery

Electronegativities of the rare-earth elements were calculated from heats of formation. The values obtained from different compounds varied widely. The postulates of Pauling's electronegativity theory were interpreted for bonds that are primarily ionic; the study showed that many compounds obey rules of the form expected. Revised electronegativity values are given for the more electropositive elements, including the rare-earth metals (which are near magnesium in electronegativity). Estimates of un-known heats of formation are made from electronegativities and are compared with other estimates. INTRODUCTION Calculation of the electronegativities of the rare-earth elements is interesting to show how these metals stand relative to the other metals and to each other, and also possibly to systematize the thermochemical data on them.

Jan 1, 1960