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By John Millhiser, Stephen J. Kravits

The U.S. Bureau of Mines preproduction Wireless Survey System (WSS) and its performance during an in-mine test are discussed in this report. The WSS was developed to reduce downhole surveying time in order to increase the efficiency of drilling long horizontal methane drainage boreholes in coal. Borehole survey data are electromagnetically transmitted from the WSS7s downhole guidance probe, via the drill rod, to the uph'ole subsystem in less than 1 min per survey transmission, regardless of borehole depth. The WSS7s in-mine test consisted of providing borehole survey data during the directional drilling of a 2,538-ft horizontal methane drainage borehole in the Pittsburgh Coalbed. By considering available drilling time, which does not include hydraulic drill downtime and the time spent traveling portal to portal, 24 shifts were needed to complete the borehole. Of the available drilling time during the tcst, 50 pct of the time was spent drilling and 50 pct surveying and maintaining the WSS to keep it operational. Previous Bureau experience indicates drilling efficiency was increased 108 pct because of the WSS, in comparison with using a commercially available wire-run directional survey instrument at 10-ft intervals.

Jan 1, 1990

By E. R. Rodriguez

Improved practice resulting from recent changes in the method of supplying compressed air and in pneumatic drilling equipment used in secondary drilling and in development work at the Morenci mine of the Phelps Dodge Corp., has resulted in improved safety conditions, as well as in a reduced cost per foot of drilling. A large stationary compressor installed outside the mining area and the compressed-air pipelines in the mine were replaced by portable compressor units. A self-propelled, self-contained drilling unit was obtained for drilling large footages where short moves were involved. Large wagon-drill units were replaced by faster and lighter drill machines and conventional bits by carbide insert bits. The safe practices employed in air drilling and in the related blasting and scaling operations have contributed to an excellent safety record at this mine. The complete sets of instructions listed in the company codes of safe practice aid materially in training employees.

Jan 1, 1956

By V. R. Miller

The Bureau of Mines has developed a technique to separate and recover the three major components, Pb, Zn, and Cd, from lead smelter flue dust. This research was conducted as part of the Bureau's effort to reduce environmental conflicts and occupational hazards associated with mineral-processing operations and to recover valuable constituents in emissions and effluents. The laboratory process utilizes sulfation roasting of the flue dust followed by water leaching to extract over 95 pct of the cadmium and zinc. Ninety-nine percent of the cadmium was recovered from solution by cementing with zinc dust, and zinc was electrowon from the resulting solution after purification. Zinc electrolysis was carried out in a 1-liter cell at 35° C with a cathode-current density of 8 A/dm2 in a solution containing 65 g/l Zn++ and 180 g/l H2S04, Current efficiencies of 80 pct were obtained. The leached residue consisted largely of PbS04, which was converted to PbC03 and leached with H2SiF6 to produce PbSiF6 electrolyte. Ninety-five percent of the lead contained in the residue was converted to electrolyte. Lead was electrowon from solutions containing 70 gil Pb++ and 90 g/l H2SiF6 using a lead cathode, Pb02-coated titanium anodes at 28° C, and a current density of 1.6 A/dm2. Current efficiencies approaching 92 pct were obtained. Accessory minerals such as cobalt and nickel were separated into purification residues and liquor.

Jan 1, 1982

By Lisa Steiner, Robin Burgess-Limerick

Working with or near underground coal mining equipment is hazardous because of the multiple sources of energy and adverse environmental conditions. Of the 4169 injuries reported to Coal Services during the three years to June 2005,447 were associated with continuous miners, 232 with LHD (load-haul- dump) vehicles, 140 with shuttle cars, and 140 with personnel transport - a total of 959, or 23% of all injuries reported during the period. An analysis of the injury narratives accompanying these injury claims highlights a number of opportunities for controlling injury risks. Using the frequency of reported injuries for the prioritisation of risk control strategies has limitations because of the tendency to underestimate the importance of relatively uncommon but potentially high consequence events. Injury reports also underestimate the contribution of risk factors such as whole body vibration, which have a long-term cumulative contribution to an elevated risk of injury. However, taking these limitations into consideration, the results of the injury narrative analysis suggests the following hazards as the highest priority for elimination or control: • handling continuous miner cable • strain while bolting • slipping off continuous miner platform • inadvertent or incorrect operation of bolting controls, and operation of controls while a person is in a position of danger • hitting potholes or other roadway abnormality • collisions while driving underground vehicles

In laboratory tests using reconstructed soil columns, rubber latex showed good sealing efficiency when applied at a rate equivalent to 4000-5000 pounds per acre. Results of field testing, however, were inconclusive. The ideal situation in which latex would coagulate in a narrow zone two to three feet below the surface by reacting with acidic or metallic constituents of the soil was not attained. Rather, the latex was deposited progressively as it passed through the soil (most of it remained in the top foot), the rate of deposition being dependent on soil structure and composition as well as on properties of the latex such as particle size and emulsion stability. Latex stability appears to be a more critical property than latex particle size in controlling penetration. Addition of excess anionic or nonionic surfactants to latex improved its penetration into the soil. A styrene-butadiene (SBR) rubber latex of 2400 Å average particle size with high mechanical stability gave the best balance of penetrating ability and sealing capacity in laboratory tests and this was confirmed in tests on a 5 x 5 foot test plot at Lanse, Pennsylvania. This latex was subsequently applied to three one-quarter-acre plots at Lanse by sprinkler irrigation, and compared to adjacent areas that were sprinkled with water only. Soil moisture measurements did not enable us to judge the effectiveness of the seal because differences between sampling positions were greater than differences between treated and untreated sections, but permeability tests showed that water flow was much slower (90-99% reduction) within the top ten inches of soil in the latex- treated sections. This sealing effectiveness was reduced after wintering. There was no deleterious effect on the vegetation as a result of sprinkling the areas with latex. A laboratory study conducted in a 5 x 5 x 5 foot box containing uniform reconstructed soil from a New Jersey source suggests that latex penetration into the soil in the field occurs mainly through natural macro openings and not through the capillaries of the soil structure. Dilute solutions of ammonium hydroxide or sodium carbonate (with no latex present) were found to seal effectively in laboratory soil columns as well as in field applications. However, since these chemicals are water soluble, the seal is temporary. Raw material costs of latex at the application rates used in the field testing are in the order of $1000 per acre. Equipment and operating

Jan 1, 1972

By Charles L. Kusik

As part of an effort to establish processes that could be exploited in case of adverse changes in international chromium production and trading patterns, this study was sponsored by the Federal Emergency Management Agency (formerly the Federal Preparedness Agency) through the Bureau of Mines, to experimentally determine the feasibility of recovering chromium from critical scrap metals containing significant quantities of this element. Based on a conceptual pyrometallurgical chromium recovery flowsheet developed at Arthur D. Little, Inc., the experimental program described in this report demonstrated key process steps for the recovery of chromium as ferrochromium in a batch process. The process involves oxidation of chromium into a slag phase, subsequent separation of the slag phase from the remaining metal, followed by reduction of chromium from the slag phase to produce ferrochromium.

Jan 1, 1981

By G. H. Hopkins

Like most industries, the refining industry has in recent years been confronted with the problem of a decreased martin of profit, due both to a general lowering of prices and to rising costs. This has resulted in accelerating a program of increased efficiency an evidenced by improved methods and the installation of equipment designed to affect a number of economies hitherto regarded as unimportant. Perhaps the most important of these has been that of fuel economy for, as is not often realized, a refinery consumes about one-tenth as much fuel as it produces. A recently completed canvas., made by the Bureau of Mines for the purpose of determining the trend of fuel consumption at refineries in the United States, showed the following outstanding points, (1) a decrease in the use of oil for fuel in 1926 of approximately 4,000,000 barrels as compared with 1925; (2) a small decrease in the use of coal; (3) a material increase in the use of gas, both natural gas and refinery gas; and (4) a considerable increase in the use of petroleum coke.

Jan 1, 1927

By J. B. Gayle

Numerous investigators have studied the addition of inert4 substances to coking blends. Generally, the results have yielded trends applicable only to the particular coals and inerts studied. Recently, somewhat more general results were obtained for cokes produced from blends containing added inerts, using the sole-heated oven. The present investigation represents an extension of this work to include a wider range of inerts and to determine the applicability of the various conclusions to cokes produced with the Tuscaloosa oven. The results indicated that an increase in dry-coal charge density of 1 pound per cubic foot (p.c.f.) caused a corresponding change in the hardness (1/4-inch tumbler index) of Tuscaloosa oven cokes of 0.9 percentage points. This value compares favorably with the value of 0.7 determined previously for the sole-heated oven and Bureau of Mines-American Gas Association (BM-AGA) retort.

Jan 1, 1961

By David E. Van Dillen

This volume is a task-by-task review of work performed in modernizing the BMINES finite element code. Much of the discussion is accomplished by cross reference to the user?s guide, which is Volume I of this two-volume report. The computer program described in this report provides for the static, three-dimensional, linear and nonlinear analysis of structural and geologic systems by the finite element method. The nonlinear material properties currently available in the code include isotropic, anisotropic, variable modulus, plastic, viscoelastic, and viscoplastic. Load application capabilities include gravity loading, surface tractions, and initial stresses. The element library includes rods, beams, plane and axisymmetric quadrilateral elements, three-dimensional brick elements, thick shell elements, and plane, axisymmetric, and three-dimensional joint elements. Special features include the ability to simulate excavation and construction sequences by means of element activity. An automatic mesh generator is included in order to simplify input preparation.

Jan 1, 1981

By N. A. C. Smith

One of the most important considerations in any manufacturing industry is the production of stable material, that is, material which will not change in quality before it reaches the consumer. The manufacturer of gasoline, the refiner of crude petroleum, is handicapped in this respect by the varying nature of his raw material, but as far as it is commercially practicable, he has endeavored to improve his product, and in most cases he has been eminently successful. It sometimes happens, however, that a gasoline that is apparently normal when first made, will In time deposit small quantities of a gummy substance. The present Investigation was undertaken in the hope that it would throw some light on these gums and indicate how their formation might be prevented.

Jan 1, 1922

By Carla A. Kertis

Because coalbed discontinuities often pose serious economic and safety problems in underground coal mines, criteria were documented for the recognition and prediction of discontinuities in advance of mining. Pennsylvanian strata in Indiana and Armstrong Counties, PA, were deposited as part of fluvio-deltaic complexes with channel-phase sandstones as the predominant type of coalbed discontinuity. Coalbed isopach maps constructed for this study delineated numerous want areas (areas of no coal) with elongate to linear geometries. A comparison of coalbed isopach and corresponding sandstone isolith maps of the study area revealed many examples of a thick-sandstone, thin-subjacent-coalbed relationship. Nearly 60 pct of the want areas in the study area were found to lie subjacent to thick (> 20 ft [6 m]) sandstone accumulations. In addition to erosion of the coalbed, channels may contribute to coalbed splitting, coalbed thinning over paleotopographic highs, abnormal coalbed thick- nesses, and deterioration of coal quality. If these features are considered, then approximately 80 pct of all interruptions in the economic coalbeds in this area result from channel activity. By using the criteria developed in this study and described in this Bureau of Mines report, the occurrence of coalbed discontinuities may be predicted and anticipated in advance of mining.

Jan 1, 1985

By D. G. Kesterke

The electrolytic reduction of uranium dioxide to molten uranium in fluoride baths at approximately 1,200° C was demonstrated. Electrolyte constituents were BaF2, UF4, and either MgF2 or LiF. Preliminary laboratory-scale experiments were made in which the uranium oxide was added continuously for 3 to 5 hours to the cell during electrolysis. Over 1,000 grams of metal of 99-8 percent purity was made in some tests, Major impurities were aluminum, barium, iron, silicon, carbon, and oxygen. The effects of cell design, geometry, and bath composition were investigated. Electrode arrangement was the most important factor in cell performance.

Jan 1, 1963

By J. E. Hamak

This publication contains analyses and related source data for 165 natural gas samples from 21 States and 1 foreign country. Of the total samples, 155 were collected during calendar year 1988. The remainder were collected earlier, but releases granting permission to publish were not received until 1988. All samples were obtained and analyzed as part of U.S. Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. This survey has been conducted since 1917. The analyses published herein were made by mass spectrometer and chromatograph.

Jan 1, 1989

By W. H. Lewis

This Bureau of Mines report and its companion report (Information Circular 9074) have been prepared as a complete reference on underground coal mine lighting. This report discusses the fundamentals of light and its interrelationship with the visual process. The purpose of the report is to insure an understanding of the numerous complex and interrelated factors that must be considered to design and implement a mine lighting system that will satisfy human needs for good vision and comfort. Topics include history, objectives, and technical considerations of coal mine lighting; light physics; light and vision relationships; and disability and discomfort glare.

Jan 1, 1986

By A. R. Taylor

The Bureau of Mines has determined the heat capacity and enthalpy values for beryllium sulfate (BeS04) throughout the temperature ranges of 10° to 300° K in an adiabatic calorimeter, and 350° to 860° K in a Bunsen-type ice calorimter, The heat-capacity data were extrapolated to 0° K, and smooth values of heat capacity, entropy, enthalpy function, and free-energy function were reported at 10-degree intervals between 0° and 300° K. The method of least squares was used to fit the enthalpy data with an algebraic equation. The equation also was used to calculate values of heat capacity, entropy, enthalpy function, and free-energy function at 50-degree intervals between 300° and 900° K.

Jan 1, 1963

By John H. Soulé

"INTRODUCTION The property of the Silver Spot Mines Co. is in the Boston Hill area within and adjacent to the southwest corner of Silver City, N. Mex. The area was visited by Bureau of Mines engineers 3/ in 1941 and 1942 during the investigation of possible sources of manganese. The area was visited again in November 1944 4/ to study the possibilities of geophysical exploration of the manganiferous-iron deposits. This geophysical work was performed in 1945 5/, confirmed the existence of known deposits of manganiferous-iron ores, and indicated the probable extent and situation of others.The Silver Spot property was churn-drilled from 1926 to 1929 during exploration for manganiferous-iron ores. The sludges from a number of the holes indicated low-grade lead-zinc mineralization. Lead and zinc minerals also were found on the dumps of some of the old shafts when the property was visited by D. H. Mullen, an engineer of the Bureau of Mines late in 1946. A diamond-drilling project was proposed. It was started in April 1947 with the intention of investigating the best of the known ore indications as shown by the old churn-drill holes and thus gathering new data upon which to base future work. Only one hole was drilled before the project was terminated because of lack of funds and time."

Mar 1, 1948

By Carla A. Kertis, Alan A. Campoli, Claude A. Goode

This Bureau of Mines study was conducted to obtain a better understanding of the coal mine bump problem and its effect on underground coal mining in the Eastern United States. To accomplish this, information was collected on the geologic conditions, mining techniques, and engineering parameters at five bump-prone mines. Two geologic conditions have been found to cause the occurrence of bumps in the Eastern United States: (1) relatively thick overburden and (2) extremely rigid strata occurring immediately above and below the mine coalbed. Additionally, the probability of bump occurrence is increased by certain mining practices that concentrate stresses during retreat mining, in areas where geologic conditions are conducive to bumps. Mining plans that permit the development of pillar line points or long roof spans that project over gob areas should be avoided because these features may contribute to the occurrence of bumps.

Jan 1, 1987

By Donald P. Tuchman, Robert P. Vinson, Steven J. Page

Researchers at the National Institute for Occupational Safety and Health (NIOSH) have long used stationary tapered element oscillating microbalances (TEOMs®) in laboratory settings. They have served to assess the mass concentration of laboratory-generated particulates in experimental , dust chambers and they provide a reference method for comparison with other particulate- measuring instruments. Current NIOSH research is focused on further adapting TEOM technology as a wearable personal dust monitor (PDM) for coal mining occupations. This investigation's goal is to help identify, quantify, and provide means for resolving certain TEOM- related error. The present research investigated bias caused by thermal effects on filter assemblies. New filters used in the PDM for 8 h tests show an average positive bias of 25.5 pg, while similar tests of equivalent filters used in two 1400A model TEOMs show an average positive bias of 34.3 µg. The derived bias values allow correction of previously collected biased data. Also, pre- heating the filters for 24 h at 46° C shows significant bias reduction, with PDM pre-heated filters subsequently averaging -3.3 µg and 1400A TEOM filters averaging 5.9 µg. On a single-point comparison to gravimetric sampling, a 25.5 µg bias is only significant at low mass loadings. At 2.5 mg, this bias represents a negligible 1 % of the mass measurement. If ordinary linear regression is used, the bias is still insignificant. However, if the more valid weighted linear regression is used, it gives more weight to the smaller dependent variable values, which are more impacted by the bias. Consequently, what is 1% bias on a single high-mass value can translate into a larger bias percentage at high-mass values when performing a weighted regression on data that include a large number of low-mass values.

By John P. Gooch

The Bureau of Mines wrote a computer program which calculates the saturation curves and condensation characteristics of gaseous mixtures consisting of binary organic vapor and air. The program employs an algorithm which assumes an equilibrium mechanism for condensation, and the degree of fractionation obtained is predicted on the basis of relative volatility. The program incorporates a feature which allows the user to examine the fractionation resulting from condensation as a function of the size of the temperature increments over which condensation is assumed to occur. If a single. temperature interval between the dewpoint of the mixture and the outlet temperature of the condenser is assumed for the calculation, the results obtained will be those resulting from a single equilibrium condensation. If the condensation is assumed to occur over a number of temperature increments, the results obtained will approach those predicted by the Rayleigh equation as the magnitude of the temperature increments approaches zero. The results from calculations performed on vapor mixtures from organic heavy liquid solutions used in beneficiating potash and brucite ores are presented. The liquids are solutions of dibromomethane in trichloroethylene or perchloroethylene. The results show the degree of liquid recovery which is possible by cooling mixtures of organic vapor in air. Compositions of the vapor range from 10 to 95 percent air, and assumed condenser exit temperatures range from 110° to 50° F.

Jan 1, 1971

By Robert L. Marovelli

The thermal conductivities of six rocks were measured by the transient line source method over the temperature range of -850 to 1,500° F. Close-fitting ceramic probes were used in 0.065-inch-diameter holes drilled through 5-to 6-inch-thick rock specimens. Taconite, granite, quartzite, and basalt were used in the tests. The method yields absolute data and is applicable to both laboratory and in situ measurements.

Jan 1, 1965