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By Wilbur I. Duvall

The borehole deformation gage and overcoring techniques developed by the Bureau of Mines form one of the primary methods of determining in situ rock stress. This report describes a least squares method of calculating the average rock stress components in the horizontal plane from more than three diametral deformation measurements in a vertical borehole. This least squares analysis provides a means of determining the multiple correlation coefficient, the variance, and the scatter for a set of deformation measurements. From this information, confidence limits can be calculated for the secondary horizontal principal stresses and their directions. The material presented in this report can be used as a guide to the development of least squares solutions for stress measurement techniques other than the borehole deformation method. Since the statistical information that results from the least squares method is extremely useful in the interpretation of results, it is recommended that a least squares analysis be used on stress measurement data whenever possible.

Jan 1, 1979

By Thomas J. Peters

The U.S. Bureau of Mines conducted a mineral investigation, and the U.S. Geological Survey did a geological appraisal of an east portion of the Bear-Marshall-Scapegoat-Swan (BMSS) RARE II area (No. A1485) to provide mineral resource information for land use planning. The Bureau of Mines' investigation consisted of a library and field search for all mineral properties and occurrences, and included a review of Teton County mining claim records. Those records showed two placer claims, the only mining-related activity known in the area. Six reconnaissance pan samples were taken in the vicinity of the two placer claims, the Lone Star and Spotted Horse, located on Hannan Gulch in 1900 and 1901. One sample contained a trace of gold, but there are no identified resources. However, the study area is in the Rocky Mountain Overthrust Belt, which is productive for oil and gas elsewhere. The entire study area is blanketed by oil and gas leases and is currently being explored.

Jan 1, 1983

By Charles L. Kimbell

While the statistical summary focuses on 1991 data, this update and outlook section draws on information available to the author as of the date of final preparation in early 1993. For all the press notoriety associated with the shift in the Near East crisis from the defensive posture of Desert Shield to the restoration of Kuwaiti sovereignty through Desert Storm, this was not the dominant event governing global economic thinking in 1991 and the first half and more of 1992. From the global perspective, the momentous political changes in the area that was the U.S.S.R. and in the smaller emerging transitional economy states of Eastern Europe will have even greater current and long-lasting effects on world mineral industry activities than the crisis in the Near East.

Jan 1, 1993

By Herbert H. Fields

The Bureau of Mines has been promoting health and safety in mining since its establishment in 1910. One area of research covers methane control in coalbeds; this report describes a multipurpose borehole used for both degasification and the production of commercial-quality gas. The multipurpose borehole was drilled into a barrier pillar, and seven horizontal degasification holes and one pressure point hole were drilled radially out from its perimeter. On January 28, 1974, after 505 days of degasification, a compressor was installed to the exhaust stack of the multipurpose borehole (1), and pipeline--quality gas was introduced into a commercial pipe-line. As of February 4, 1975, over 171 million cubic feet of gas had been purchased by the gas company. The in situ pressure at a depth of 200 feet into the coalbed and the average gas flow and water flow from the degasification holes as they were completed and closed off were 203 psig, 1,200,000 cfd, and 6.8 gpm, respectively. Twenty-four hours after the seven holes were connected through individual pipes to the atmosphere, the total gas and water flows and the in situ pressure dropped, respectively, to 971,000 cfd, 1.3 gpm, and 18 psig. Five hundred days later, the corresponding values were 620,000 cfd, 0.15 gpm, and 10.5 psig. Daily flows have been as high as 800,000 cfd, and as low as 360,000 cfd, during the last 500 days. On February 4, 1975, after 882 days of degasification, 576 million cubic feet of gas had been removed from the Pittsburgh coalbed; apparently a much larger area of virgin coal is being degasified than is defined by the holes. This study indicates that horizontal boreholes drilled into a coalbed from the bottom of any shaft will effectively remove gas from the Pittsburgh coalbed,

Jan 1, 1975

By John H. Perry

The Bureau of Mines has developed several techniques for draining methane from coalbeds in advance of mining. Drilling long horizontal holes from an underground location is one such technique, which was successfully demonstrated in the Pittsburgh and Sunnyside Coalbeds. The same technique has now been applied in the Mary Lee Coal bed at Jim Walter Resources, Inc.'s No. 4 Mine, Brookwood, Ala., where two holes were drilled horizontally--one to a depth of 1,010 feet (308 m) and the other to 540 feet (165 m). The 1,010-foot (308-m) hole proved successful in degasifying a portion of the Mary Lee Coalbed. The hole drained methane for 1 year, during which time the initial gas flow of 200,000 ft3/d (5,663 m3/d) declined to 65,000 ft3/d (1,840 m3/d). Total gas production was 40 x 106 ft3 (1.1 x 106 m3). The gas was of commercial quality, with 98 pct methane and a heat rating of 990 Btu/ft3 (36.89 Mj/m3). The methane emissions from the faces of the mine section advancing into the degasified zone were reduced by 60 pet. The 540-foot (165-m) hole was terminated prematurely when it became impossible to maintain an open hole. Because of caving, very little gas was drained through this hole.

Jan 1, 1982

By Roy C. Bartholomae

This U.S. Bureau of Mines study found that the performance of the active noise cancellation hearing protector in a reverberant field was mixed. The performance varied when the conditions changed from ideal to nonideal. The active noise cancellation (ANC) component provided substantial additional noise reduction from 125 to 500 Hz for all testing conditions (broadband noise or pure tones both with and without safety glasses). While the ANC under ideal conditions provided additional attenuation from 500 Hz and below, under nonideal pink noise conditions the ANC amplified noise below the 125-Hz third octave band. There was a middle band of frequencies at which the ANC amplified noise levels ranging from 630 to 4,000 Hz. The results for pure tones showed that attenuations were higher but that they followed the same general trend.

Jan 1, 2010

Control dust generated during overburden drilling at surface coal mines using either wet suppression or dry collection systems. Approach For the wet suppression systems, a range of water flow rates was tested over a number of holes. Each hole was drilled at a specific and constant flow rate. A recording flow meter was mounted in the water line near the control system pump. For the dry collection systems, each drill was tested with the front of the shroud set at different heights above the ground. Because of the irregularity of the ground surface, all height measurements were taken at the front of the shroud. Background Wet drilling systems consist of a water tank mounted on the drill from which water is pumped into the downhole air line. The water droplets in the bail air conglomerate dust particles as they travel up the the annular space of the drilled hole, thus controlling dust as the air bails the cuttings from the hole.

Jan 1, 1987

Develop a method for control of groundwater inflow to chronically "wet" sections of underground coal mines, in order to reduce groundwater interference with mining activity and to minimize acid mine drainage. Approach In eastern coal regions, groundwater stored in fracture zones in the rock mass can create a significant water problem for underground mining operations. Fracture stored inflow to mine workings impedes mine productivity since storage water sources usually release at the active face, creating the poor mining conditions typical of a "wet" section. Fracture water can also contribute to AMD problems when the water subsequently contacts sulfide minerals in the coal, The Bureau of Mines has developed a mine-dewatering method that eliminates many of the problems associated with mine water inflow by draining these fracture zones before the water can reach the developing face and interfere with mining activity. How it Works The dewatering method removes large volumes of the stored groundwater through high-capacity pumping from a minimal number of wells placed strategically on fracture traces (the surface expressions of fractured rock zones). These fracture traces are located through low-level aerial photographic and geologic investigation. As shown on the map, dewatering wells are sited precisely on fracture trace intersections in order to take advantage of the increased pumping capacity gained from these zones of high permeability. Once well drawdown indicates that the stored water is depleted,

Jan 1, 1983

The Bureau of Mines believes that all coal mines are potentially gassy; for the purpose of administration in the prevention of explosions and fires, the Bureau recommends: That any coal mine wherein methane or other combustible gas can be detected in amounts as much as 0.27 of 1 percent or more by frequent systematic searches shall be classified as a gassy mine. Permissible methane-indicating detectors such as are given in I.C. 7110 or subsequent lists of Bureau approved methane-indicating detectors, or conventional methods of sampling and analysis of required accuracy may be used. The concentration referred to in the decision is percent by volume.

Jan 1, 1941

By John C. Machisak

THE INJURY data and related employment experience of the coking industry in the United States for 1955 arc presented in this publication under the following general sections: (A) General Injury experience: Tables 1 to 9: Contain current and comparable data on operating statistics, number and classification of injuries, injury-frequency rates, and accident agencies involved in causing injuries. Data are tabulated for the industry as a whole, for each typo of oven: and for the States in which coke is produced.

Jan 1, 1958

By Charles L. Kimbell

In broadest overview, a substantial part of the world's mineral industry in 1990 registered small gains over its 1989 performance, but traditional statistical measures of mineral industry performance, namely global production, trade, and consumption levels, failed to mirror these gains. This was because of the sharp downturns in the mineral industry activity in the U.S.S.R. and the former centrally planned economy nations of eastern Europe. These downturns in this one geographic area had influences on almost all traditional statistical series, in some cases simply significantly reducing growth, in other cases providing for a global downturn, in almost all cases despite considerably brighter outlooks based on activities in other world areas. To be sure, the U.S.S.R. and eastern Europe were not the only places on the planet suffering problems of one type or another in 1990 that impacted on minerals industry activity, but with the acquisition of information presently available, it seemed almost assured that the difficulties of these economies in transition will be the most difficult of problems to resolve in the long run. It certainly appeared that the legacy of the half century or more of economic central planning will be a decade or more of very difficult adjustments, and a number of these will greatly affect not only the minerals industry of these transition countries, but also the rest of the globe's mineral industry as well.

Jan 1, 1993

By W. P. Yast, R. R. Slyers, J. H. Hildebrand

 The Bureau of Mines, in conducting investigations of atmospheres in mines and tunnels for the purposes of determining and combating hazards to the health and safety of workers, has from time to time closely cooperated with municipal, State and Federal agencies in safety work in engineering and ventilating probleme. Recently the writers have conducted experiments with animals and men breathing helium-oxygen mixtures under pressure. The object of this work was to determine whether helium-oxygen atmospheres can be utilized to advantage in place of normal air for caisson and diving work. In such work the permissible pressures and times of compression and decompression are limited by the physiological effects on man. The major effect is that the nitrogen, (which is the inert con- stituent of normal air and is absorbed by the body tissues and fluids in abnormal amounts when under pressure,) tends to form bubbles in the tissues on too rapid discompression from high pressures. The Bureau of Mines is interested in this problem on account of the pos- sibilities of mitigating caisson illness in tunnel construction and other engine eering operations requiring men to work in compressed air. In addition, the Navy Department is interested on account of the possibilities for extending the range of salvaging and marine engineering operations. The results of the experiments conducted by the writers lead to the following conclusions: Helium is without odor or taste and has physical properties which promise to be of interest physiologically and which have been found to have possibilities of creat practical use, especially in making a synthetic atmosphere that will re- duce the hazard of caisson disease. The substitution of helium for the nitrogen ordinarily present in the air we breathe has been found to result in an atmosphere which it as respirable as that provided by nature. The results obtained indicate that helium not only has the advantage of being less soluble than nitrogen, but

Feb 1, 1925

By D. E. Hirsch

The types of compounds present in aromatic concentrates derived from high-boiling petroleum distillates can be estimated from a gel permeation chromato-graphic (GPC) analysis by the use of tables developed from extensive GPC and mass-spectral analyses on fractions from four crude oils. For a fraction from the GPC analysis, the retention volume and the molecular weights (from mass spectrometer) suffice to indicate the types of compounds which predominate. The tables which show these qualitative analyses were developed through the use of pure compounds as well as the extensive analyses on Prudhoe Bay (Alaska), Gach Saran (Iran), Swan Hills (Canada), and Wilmington (California) crude oils. These tables provide a rapid method for determining which types of compounds are present in a GPC fraction before attempting to develop quantitative data.

Jan 1, 1974

By J. V. Batty, K. C. Dean, H. D. Snedden, W. J. Long

As a part of the investigation of strategic-mineral deposits in the United States under the Strategic Minerals Act, engineers of the Bureau of Mines examined and sampled numerous deposits of fluorite ore from Utah. From those deposits that warranted further investigation, samples were submitted to the Ore Dressing Section of the Salt Lake City Station for metallurgical testing. This paper gives data summarizing the results obtained from laboratory ore-dressing studies of the fluorite ores submitted. Test work was done on samples from four properties in the Washington Mining District, Beaver County; two properties in the Star Mining District, Beaver County; one property in the Wah Wah Mountains, Beaver County; and three properties in Tooele County, Utah. In general, the Washington District ores were found amenable to concentration by flotation for the production of acid-grade fluorspar. None of the other ores were beneficiated to acid-grade, but several were amenable to concentration for the production of metallurgical-grade fluorspar concentrates.

Dec 1, 1947

By J. V. Batty, K. C. Dean, H. D. Snedden, W. J. Long

As a part of the investigation of strategic-mineral deposits in the United States under the Strategic Minerals Act, engineers of the Bureau of Mines examined and sampled numerous deposits of fluorite ore from Utah. From those deposits that warranted further investigation, samples were submitted to the Ore Dressing Section of the Salt Lake City Station for metallurgical testing. This paper gives data summarizing the results obtained from laboratory ore-dressing studies of the fluorite ores submitted. Test work was done on samples from four properties in the Washington Mining District, Beaver County; two properties in the Star Mining District, Beaver County; one property in the Wah Wah Mountains, Beaver County; and three properties in Tooele County, Utah. In general, the Washington District ores were found amenable to concentration by flotation for the production of acid-grade fluorspar. None of the other ores were beneficiated to acid-grade, but several were amenable to concentration for the production of metallurgical-grade fluorspar concentrates.

Dec 1, 1947

By James R. Jones

"The General Leasing Law, which provides for the leasing of deposits of coal, oil, oil shale, gas, phosphate, and sodium in public lands, was approved February 25, 1920.One of the outstanding features of this legislation is the fact that it opens for prospecting and exploitation lands and deposits which have been withdrawn from public use, some of them for several years, pending enactment of legislation better fitted to control the mining and utilization of the particular mineral deposits referred to. These lands are not only made available to the public, but they are opened up under a system which defines better than was ever done in the pas the rights which may be acquired under it.The oil operator, for example, under this legislation will know definitely the extent of the rights he has acquired, as well as the legal conditions under which his expensive drilling and other work of exploration are to be conducted. No longer will he be harassed by the possibility that while he is spending his capital in drilling operations in an effort to make a discovery of oil, his legal rights be contested, in which event the superiority of his claim can only be upheld -- if at all -- after long and expensive litigation. By the same token the coal operator will now be free from the embarrassing restrictions of the old coal-land laws respecting the amount of such land which may be purchased by one person.At the same time that these advantages are being enjoyed by the operators, the public will be guarded against wasteful methods of drilling and mining the oil and gas, and coal deposits, and the other mineral substances enumerated in the act, to the end that these products of Nature, which can not be replaced, may be utilized with a minimum of loss."

Mar 1, 1920

By A. V. Petty

In accordance with its objective to maximize minerals recovery from secondary domestic resources, Bureau of Mines conducted research on recycling chrome refractory wastes. Since 20 pct of the U.S. demand for imported chromite is used in the production of refractories, primarily for the steel, copper, and glass industries, samples of used chrome-containing refractories from copper converter and reverberatory furnaces were investigated to determine their potential for recycling. The samples were beneficiated using a combination of wet magnetic separation, flotation, and leaching techniques, and the concentrates were reformed into briquets for refractory evaluation. Small refractory test specimens produced from the beneficiated concentrates gave modulus of rupture values at 1,350° C comparable to those of commercial mag-chrome brick of similar composition; however, grinding the waste refractories to at least minus 65-mesh was required in order to liberate the metallic copper. Most of the copper was easily recovered using conventional beneficiation techniques, but the finely ground chrome concentrate would require briquetting, calcining, and crushing to produce a coarse grain suitable for recycling into secondary mag-chrome refractories.

Jan 1, 1981

By John A. Davis, John Gross

This paper is one of a series giving the results of metallurgical tests conducted by: the Alaska station of the Federal Bureau of Iſines, on the recovery of gold from the black sands of placer clean-ups. The data given in this report were obtained from tests on a lot of black sand from a property located on St. Patrick Creek, Fairbanks mining district, Territory of Alaska. This property comprises the Sagan Fraction and adjoining bench claims, and is being operated by J. A. Lillie. The sand ad already been treated at the mine by amalgamation. A sample taken by Mr. Lillie and assayed at the station showed that the gold still remain ing amounted to ll cents per pound. As this gold content was sufficiently high to justify further treatment of the same, 770 pounds were shipped to the station for testing. The reader will note that the gold content is given in cents per pouni, rather than per ton. This is in conformity with practice in the district in valuing black sands, as the quantity obtained at any one time is small, much less than one ton. . The sand consisted principally of schist and quartz, with very little ilmenite and garnet; and no magnetite or sulphides. Most of the gold present as contaminated with quartz, as the free particles of gold had been removed by amalgamation at the mine.

Sep 1, 1920

By Oliver Bowles

"Waste Granite in the Barre, Vermont, District: Waste in the great granite center at Barre, Vermont, consists of three types of material, the rough blocks rejected at the quarries on account of imperfections, the chips or spalls resulting from trimming and dressing at the cutting plants, and the granular and pulverized material from the dust collectors. The waste piles at the quarries of are immense proportions and constitute a serious handicap to quarrying in that they cover up good rock deposits, and are also so large that waste disposal becomes more and more expensive. The problem of utilization of such waste material is a topic of keen interest to all granite producers.Barre is not situated on a water route, and thus transportation costs prohibit the shipment of waste blocks for rip rap or ballast. Crushing plants use a small amount of this material for road construction, but aside from this, the waste is practically valueless.Investigators of waste utilization problems are awaiting with interest further information concerning an enterprise undertaken at Montpelier, Vermont, to utilize crushed granite for the production of brick similar to sand-lime brick. Granules of granite are mixed with lime, moulded, and hardened under steam Pressure, The brick produced are said to be of excellent quality for structural Purposes.There seems to be no logical reason why waste granite could not be utilized for the manufacture of building stone, and paving blocks, for many of the defects which condemn a stone for monumental purposes are not at all detrimental for building or street paving. F or the most part, monumental stone workers are not particularly interested in other branches of the granite in-dustry, and a combination of industries such as that suggested"

Jan 1, 1920

By J. T. May

The Federal Bureau of Mines investigated the extraction of lithium from hectorite-type clay deposits found on the Nevada-Oregon border. Two clay samples were used in the investigation; one contained 0.36 pct Li and the second contained 0.64 pct Li. The purpose of this laboratory-scale research was to determine how these clays responded to different extraction techniques. Extraction techniques investigated were sulfuric acid leach, sulfuric acid bake-water leach, and roast-water leach procedures with cholorides, sulfates, carbonates, and combinations of these reagents. The processing characteristics of the clay samples showed significant variations, and no one technique was effective for both materials. Lithium extractions near 90 pct were achieved during these exploratory studies.

Jan 1, 1980