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Determine the extent to which remote-sensing techniques, primarily lineament analysis, can be used to identify geologic structures that may affect the location and migration of subsidence over abandoned underground coal mines in the Colorado Springs, CO, area. Compile data using a geographic information system (GIS) to allow efficient and reproducible comparisons and analyses. Background The basis for evaluating abandoned mine land (AML) sites with remote-sensing techniques comes from past and ongoing Bureau ground control research using remote-sensing data to identify potential hazards caused by geologic structures (faults, joints, etc.) above active underground coal mines. Research showed that lineament (linear feature) analysis of Landsat Multispectral Scanner (MSS) images could indicate locations of fractures and fracture trends that had varying, but significant, impacts on the stability of mine openings. Such geologic structures should be identifiable over abandoned mines as well. If fractures are present, even if they arc not faults, they should represent areas of potential instability over these mines and, therefore, should tend to localize subsidence when it occurs, particularly for deep and moderately deep portions of mines.

Jan 1, 1992

By S. D. Maksimovic

The Bureau of Mines evaluated the hydraulic stimulation of a gob-degasification borehole to determine if this procedure would aid in degasifying a longwall panel. The stimulated borehole did not degasify the longwall panel as expected either before or after mining of the panel started. It reduced the underground methane emission only 11 pct, considerably less than the reductions effected by two unstimulated boreholes in the same panel. Some probable reasons for the reduced methane flow from the hydraulically stimulated borehole are very low reservoir gas pressure, location of hydraulically stimulated zones within the grouted casing, a casing break caused by lateral shifting, possible vertical movement of rock strata during caving, grouting of a 4-inch pipe blocking three stimulated zones, plasticity of shales, and possible hole damage by swelling of water-sensitive minerals. The borehole was also located between two second-mined areas, which may have allowed partial degasification of the overburden and the coalbed in advance of mining. Finally, a period of 3 months is probably not long enough for the borehole to degasify the overburden before mining.

Jan 1, 1977

By W. P. Yant

The hazard to health from contamination of air by a noxious gas depends not only on the potential harmful response attending exposure., but also on the warning properties, which in effect may be termed the "accompanying warning response," This warning may be manifested as an odor, taste, irritation of the eyes, nose, or throat, or perhaps headache, vertigo,, or nausea. These manifestations may be painful and even slightly harmful, but to a much lesser degree than the primary injury of exposure. The warning response mitigates hazards directly in proportion to the degree of intolerability which -accompanies injurious exposure, and accordingly its absence augments hazards. This accounts for the fact that the actual health hazards from a nonodorous or non-irritating gas or vapor of comparatively low toxicity sometimes equal or exceed the hazard from a considerably more toxic substance, but one which possesses a marked odor or produces eye, nose, or throat irritation in advance of harmful exposure. When a substance lacks the properties for giving warning, it is often possible to impart them by the addition of a small amount of another substance which has an exceedingly high warning intensity. The vapors of this substance, commonly termed a "warning agent" or "tracer gas," escape and mingle with the gas or vapor which lacks warning properties and thereby apprises persons of the latter's presence. The amount of the warning agent added is that which will give adequate warning in advance of serious physiological harm from the dangerous gas or vapor.

Jan 1, 1930

By Jeran Paul W., Michael A. Trevits

Subsidence data gathered by the U.S. Bureau of Mines over a series of longwall panels in the Pittsburgh Coalbed were studied to obtain insight as to the role of time in the subsidence process. It was found that subsidence began essentially with undermining and was completed within 1 year. The progress of the subsidence was dependent upon location above the panel. Subsidence in the central area of the subsidence trough, where subsidence is the greatest, was about 90 pct complete by the time the face had progressed a distance equal to one overburden thickness beyond a particular surface point. For a point over the rib of the longwall panel, the subsidence was only about 60 pct complete at this time. Data from three other sites in the northern Appalachian Coal Basin were analyzed to determine if an anomaly or the true characteristics of the subsidence process had been observed. All sites behaved similarly in the central portion of the subsidence trough. However, the subsidence of points over and adjacent to the ribs of the longwall panels was site specific. The fact that movement across the width of the panel was not uniform should be taken into account in assessing damages or the potential for damages resulting from mining-induced subsidence.

Jan 1, 1995

By T. E. Sterner

A laboratory investigation was conducted to determine the applicability of the thermal oil-recovery method as a means of increasing ultimate oil recovery in the Appalachian region. The primary objective was to establish self-sustained combustion in consolidated and unconsolidated sand test assemblies saturated with various amounts of Pennsylvania Grade crude oil and synthetic brine. Tests using blocks of sandstone were unsuccessful because of sealing problems and fracturing of the rock due to thermal stresses. A combustion wave of about 700° F was propagated through the sand-oil-water packs in the linear tube tests. The high air flux used resulted in high oil consumption and rapid movement of the combustion wave through the tubes. Analytical tests on the sand pack showed that sufficient fuel was deposited during the linear tube experiments for a self-sustained combustion wave.

Jan 1, 1967

By S. W. Lambert

In this Bureau of Mines investigation, production was monitored for 1 year at over 30 coalbed gas-drainage boreholes located in Alabama, Pennsylvania, and West Virginia. Results indicate that the quality of data gathered from such wells can be improved greatly if potential problems are anticipated and prevented in the early stages of well production. Major water-monitoring problems include solids buildup, freezing, the presence of gas in surface waterlines, and improper pumping interval settings. Such problems may be avoided by incorporating in the original well design waterline filters, sand screens, separator tanks, and systems to automatically control pumping intervals. Problems related to measurement of coalbed gas flow include large quantities of water vapor contained in the gas, especially during winter months; freezing and subsequent obstruction of flow; sudden, uncontrolled release of gas pressure; and solids buildup in metering equipment. The installation of commercially available items, such as filters, separators, and insulation, and the thoughtful application of a basic knowledge of coalbed gas reservoir characteristics will prevent most production-monitoring problems.

Jan 1, 1978

By F. N. Kissell, H. K. Sacks

This study examines the accuracy of area sampling for measuring the dust exposure of mining machine operators in coal mines. The specific objective of this research was to find locations where an area sampler might work better than earlier studies have indicated. The results show that fixed-location area sampling cannot accurately predict the dust exposure of a machine operator, even when the best fixed location is sought, the fixed location is quite close to the operator and the bias due to the dust concentration gradient is corrected. Industrial hygienists have known for many years that area sampling is unsuitable for measuring air contaminant exposures in the workplace. Near contaminant sources, the dilution air and the contaminants are not evenly mixed. Therefore, when workers are near contaminant sources, exposure measurements must be taken from the worker's breathing zone to be accurate

By P. L. Loyselle, B. D. Comilsen, D. H. Carlson, J. H. Johnson

"In-mine airborne particulate samples have been successfully collected and the relative amounts of diesel and coal determined using the Laser Raman Quantitative Analysis (LRQA) method. This method allows analysis of filters which have been collected by a method similar to that used to determine the airborne respirable dust concentration in us underground coal mines. Samples were taken near the feeder-breaker, on haulage vehicles, and in the returns. Sampling methodologies were developed for coal-only and diesel-only particulate reference samples with sufficient filter loading for the LRQA method. A statistical analysis of reproducibility has been carried out. Samples have been collected simultaneously at two locations using the LRQA and the size-selective sampling methods. Good agreement between the two methods has been found.INTRODUCTIONThe goal of this research has been to develop the Laser Raman Quantitative Analysis (LRQA) method to measure the composition of respirable particulate, i.e. the fractions of coal and of diesel particulate, in the mine ambient air. In earlier Bureau of Mines sponsored research, we successfully demonstrated that the LRQA method could be used to measure the fraction of Diesel Particulate Matter (DPM) in coal/diesel particulate mixtures which were prepared in the laboratory.(I) 'The immediate objective was to test and refine this LRQA method on samples collected in a diesel underground coal mine.Specific objectives required to meet this goal include:I) Develop in-mine sample collection methods which will insure sufficient particulate loading on filters for LRQA. ,2) Develop methodology for in-mine collection of reference samples (""coal-only"" and ""diesel-only"" filters) which arc required for quantitative LRQA. 3) Analyze precision and accuracy of the LRQA method. 4) Compare composition measurements with another analytical method, i.e. the University of Minnesota/Bureau of Mines size selective sampling Micro-Orifice Uniform Deposit Impactor (MOUDI) method.An advantage of the LRQA method is that it allows analysis of filters which have been collected by a method similar to that used to determine the respirable dust concentration in US underground coal mines. No new sampling instruments and techniques are required. Transfer of sample from collection substrate to analysis substrate is not necessary. Furthermore, other analyses can be made on the same sample since the technique is nondestructive."

Jan 1, 1988

By Oliver Bowles

From the most remote periods of civilization stone has been used to perpetuate the memory of individuals or to immortalize their noble achievements. Ancient memorials ranged from simple piles of stone (cairns), or single markers, to great obelisks and pyramids or magnificent mausoleums. The Taj Mahal at Agra, India, built of white marble by Shah Jehan in memory of the Empress Mumtaz Mahal, is one of the most beautiful and costly memorials ever built. It was erected between 1632 and 1650 at an estimated cost of $50,000,000 or more and is today an object of unusual interest for travelers. Other magnificent memorials both ancient and modern are to be found in many lands. No sharp line can be drawn between buildings and monuments, because the larger types of memorials such as the Bok Singing Tower, Lincoln and Jefferson Memorials, and mausoleums of various types have features in common with buildings. However, great care must be exercised in selecting a site for a quarry that will produce acceptable monumental stone because appearance as well as quality is of prime importance. The deposit must be of uniform texture and attractive color and must be notably free of knots, hairlines, impurities, incipient seams, or other defects. Many memorials are of polished stone, and spots or streaks that might be virtually Invisible on a natural rock face will appear distinctly on a polished surface. Hence, stone to be polished must be selected with unusual care. However, less flawless stone may be used for hammered surfaces.

Jan 1, 1955

By P. C. Good

The work reported here was undertaken by the Federal Bureau of Mines to investigate new methods of preparing high-purity metal. Tungsten hexachloride was prepared by direct chlorination of scrap tungsten metal and by treating tungstic oxide with carbon and chlorine. The resulting tungsten hexachloride was purified by distillation and reduced win: sodium, magnesium, or hydrogen. The metal prepared by these techniques was at very high purity after arc melting but of variable quality prior to arc meIting. Metal recovery ranged from about 40 to 90 percent of theoretical values, It was found possible to deposit a smooth, dense coating of high-purity tungsten on the inside of a heated tube by vapor-phase reduction of tungsten hexachloride at reduced pressure.

Jan 1, 1961

By Raymond B. Ladoo

The Bureau of Mines frequently receives requests for information on the mining , preparation and marketing of epsomite or Epsom salt , and in order to answer such inquiries the following information has been compiled . While it is probable that few people have considered epsonate as a mineral product , it will be noted that it should be so regarded and its production forms an important industry .

Mar 1, 1922

By C. N. Schuette

"The production of silica and magnesia crucibles in the induction furnace was attempted and achieved in the laboratory of the Pacific Experiment Station of the United States Bureau of Mines. This work was undertaken at the request of other stations for laboratory crucibles of a certain specified wall thickness and capacity.The essential new parts of this work are the development of a technique for the high-frequency furnace production of silica crucibles of greater wall thickness than could be readily fabricated from commercial fused silica, and for heavy-walled magnesia. crucibles of great density and mechanical strength. A considerable bode of patent literature on the Production of fused silica ware in resistor-type furnaces was examined, but it furnished no significant help for the present problem. Similarly sintered magnesia refractories are often made for technical purposes, but for use at temperatures of 2000o C. or over, the material must be sintered at higher temperatures than can be attained by combustion firing, and the very great shrinkage encountered at these temperatures requires special methods. Small crucibles. of magnesia fused in the electric arc have been made by Tritton and Hansen,3 but the practical size of such containers is very limited.Many different methods of making crucibles in the induction furnace were tried before satisfactory results were obtained. The following description covers only the most satisfactory method, which produced crucibles of excellent quality in a reasonable time and with a moderate expenditure of power and materials."

Oct 1, 1929

By N. B. Greninger

The U.S. Bureau of Mines conducted explosion tests on various full-scale cementitious bulkheads used in abandoned mine areas to evaluate the ability of the bulkheads to withstand gas explosion over-pressures of 20 psig. Tests were performed on 120-ft2 solid-concrete-block seals of varying thicknesses and designs. Of the seven solid-concrete-block seals tested, only the standard-type seal, having a 16-in thickness, keyed at the floor and ribs, all joints mortared, wedged at the roof, and a center pilaster, maintained its integrity when subjected to a 20-psig pressure wave. After being subjected to repeated explosions, the standard seal only showed a small hairline crack and had an air leakage of 87 ft3/min at a pressure differential of 1 in H2O. Tests were performed on cementitious foam seals of varying thicknesses and compressive strengths. Explosion tests have shown that 200-psi strength, 4-and 8-ft-thick seals can withstand a 20-psig pressure wave. At a pressure differential of 1 in H20, no air leakage was detected through the 200-psi, 8-ft-thick foam seal.

Jan 1, 2010

By Peter N. Gabby

A mineral survey of 8,300 acres of the 24,980-acre Burnt Creek Wilderness Study Area (ID 45-12), was conducted by the U.S. Bureau of Mines in 1985 at the request of the Bureau of Land Management. The study area is located in Custer County, ID, 90 miles northwest of Idaho Falls. No mines, claims, or prospects are in the study area. The northern half of the study area and adjacent lands to the north, northeast, and east are or were recently under oil and gas lease, Basalt and latite-andesite of the Challis Volcanics predominate in the study area. Several hundred feet east of the study area is a quarry in talus of Mississippian-age limestone that was used for sized 100-pound rock fill in the Old Dry Creek Reservoir dam. Two samples, one taken at the quarry and the other at a limestone outcrop on East Fork Burnt Creek, have CaC03 content in the range of 90 to 95 percent, and is suitable as the limestone component of Portland cement, However, limestone outside the study area could supply foreseeable demand. Lead- silver mineralization has been observed in Paleozoic carbonate rocks elsewhere in the Lost River Range, but these rocks do not occur in the study area.

Jan 1, 1986

By H. A. Watson

Fluorine-containing polymers are comparatively new materials that exhibit very desirable characteristics not usually found in non-fluorine containing polymers. Among these characteristics are heat and flame resistance, desirable electrical properties, and chemical inertness. Polytetrafluoroethylene and polymonochlorotrifluoroethylene are examples of such polymers commercially available. In practical applications it is reasonable to expect thermal position of these materials if they are subject to high enough temperatures. The temperatures at which thermal decomposition takes place and the nature of the gaseous products of decomposition are considered pertinent data in intelligent use of these materials. The purpose of the tests discussed herein was to determine: (1) The temperatures at which gases were produced when small specimens of the two polymers were located and (2) determine the identity of the major constituents of gaseous products.

Jan 1, 1950

By Thomas Fraser

The Convertol process, recently developed in western Germany, is a new method of cleaning and dewatering coal-washery slurries. It is a modified bulk-oil process, in which a very small quantity of heavy oil is dispersed over the surfaces of the coal particles, followed by a screen centrifuge operation in which the water and dirt (clay, shale, and pyrite particles) are thrown out through the screen perforations and the clean coal particles are retained on the screen and discharged as a dewatered, clean coal product of 8- to l0-percent surface moisture. It is reported, also, that the process oil, all of which is retained in the clean-coal product, adds to the coking power of the coal and facilitates the production of briquets, reducing the proportions of binding material required.

Jan 1, 1953

By R. L. Schmidt

Research conducted over the past 20 years in France, Great Britain, and the United States on the use of the large-hole burn cut has established cer¬tain advantages for this system. Advantages include longer pull and more complete fragmentation from blast rounds. However, research is needed to establish a set of parameters for optimum performance. As part of the Bureau of Mines Advancing Mining Technology for Marginal Resources program, the Twin Cities Mining Research Center, Twin Cities, Minn., acquired a horizontal rotary drill capable of boring holes up to 24 in. in diameter. This was used for a series of underground experiments at White Pine mine, White Pine, Mich., during 1973. Exceptional results were obtained with a 12-1/4-in void hole that yielded up to 18 ft of pull in a 10- by 20-ft drift, Fragmentation was excellent, and the compactness of the muck pile facilitated loading.

Jan 1, 1975

By F. L. Wideman

SPURRED by demands of a buoyant economy for mineral products, output from mines in the United States established a new record. Removal of waste material, necessary for the extraction of economic minerals, kept pace with mine production. Earth moving by these two activities exceeded 3 billion tons, an increase of 5 percent over that of 1963. Crude materials from which metal or nonmetal products were derived accounted for 75 percent of the total. The remainder, mostly worthless, was classified as waste. Changes in the minerals industry result from many causes. Technological trends and labor productivity are among several significant and interrelated indexes that assist in the analysis of the changes. Therefore, a. study of productivity is helpful in measuring technological growth in mining. Concepts of productivity tend to vary with the purpose for which the term is used; frequently, productivity is expressed in terms of units of output per unit of labor, such as tons of ore per man-hour or man-shift. Comparisons of levels of productivity for a group of products are usually made using composites of output. Data for all metal and nonmetal mines except gold, silver, mercury, platinum metals group, and sand and grave were used to compile the composite for determining productivity for 1960-64. Copper ore, iron ore, and phosphate rock are mined mainly by surface methods, but characteristics of the deposits and differences in processing the crude material affect production of the commodities. Therefore, productivity data for these selected segments of the minerals industry reflect the influence of physical conditions on the exploitation of them.

Jan 1, 1965

By Ralph L. Windrow

This paper is one of a series being prepared for and published by the United States Bureau of Mines describing methods and costs of mining and preparing sand and gravel for market at various plants throughout the United States. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total costs. It is recognized that publication of total costs might in many instances cause embarrassment to individual producers as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. The Clowdy plant, with which this paper deals, is located 7 miles west of Dallas, Tex., and has a rail connection with the Texas and Pacific Railway. In addition to the rail outlet there is a paved road over which materials produced at this plant can be moved into Dallas by truck.

Jan 1, 1932

Heavy liquids have come into use in ore-dressing investigations, as they make possible the separation of an ore into its specific-gravity components. A paper containing a general dissertation on heavy liquids has been written by John D. Sullivan,4 and the practical application of heavy liquids is explained by Box and Crabtree5. Some heavy liquids become discolored after continued use, and the lack of transparency impairs their value. Since they are fairly expensive, reclaiming is desirable. This paper briefly discusses the preparation and care of some of the more common heavy liquids.

Jan 1, 1928