Search Documents

By C. O. Hawk

Distillable oils derived from coal were desulfurized and hydrogenated at 2,500 psig in a two-step vapor-phase catalytic operation to give a product rich in saturated cyclic hydrocarbons. The first step was mainly a desulfurization at 400 C, the second a saturation at 300 C. One of the oils used as feed stock was from low-temperature carbonization of a bituminous coal, the other was from the liquid-phase hydrogenation of coal in the Bureau's pilot plant. The product from the saturation step was distilled to remove the light ends and high-boiling residue and to recover a fraction having acceptable properties with respect to heating value, density, freezing point, viscosity, and boiling range according to specifications suggested by the Air Force for ultra-high-speed aircraft fuel. Quantities of the fuel fraction available were too small for the thermal stability test approved by the Air Force. The experiments, performed on laboratory scale, comprised mostly a study of the effect of varying the oil feed rate (at constant oil-to-hydrogen ratio) on the yield of the desired fuel fraction. The yield of the fuel fraction made from low-temperature carbonization oil was a little more than 1 percent of the weight of coal carbonized; that from coal-hydrogenation oil was about 12 percent of the weight of coal hydrogenated. A few attempts to do both desulfurization and saturation in one operation with sulfur resistant catalysts, developed for vapor-phase hydrogenation or hydroforming, were unsuccessful. By leaving the low-boiling ends in both feed stocks to desulfurization, another product was obtained: a low-sulfur aromatic cut boiling below 200 C. This material would be suitable as a solvent or a chemical raw material.

Jan 1, 1965

By Stephen C. Tadolini, Thomas M. Barczak, Paul McKelvey

A new generation of hydraulic mine support prestressing devices has been developed. These thin-walled steel shells are machine-welded and can be inflated with water or any liquid to provide prestressing for a wide variety of roof support products ranging from Can supports to props and cable bolts. With an expansion capability of several inches, depending on the geometry and size of the unit, they can also establish roof contact eliminating the need for wooden wedges or crib blocks that are commonly employed with several standing roof support products. Capable of withstanding pressures from 1,000 to 6,000 psi, these cells are able to transfer roof loading into the support structure without rupturing. A recent development has been the addition of an inexpensive yield valve that provides control of the maximum pressure and load development on the support. This paper examines the performance capabilities of these inflatable prestressing units and the impact they have on the performance of various support systems, including an evaluation of the overall stiffness of the support system and the load control during yielding of the prestressing unit. Recommendations are made regarding the design requirements of the prestressing unit to optimize the support performance. A summary of mine applications using this technology is provided with general comments regarding their impact on ground control.

Through a contract, the Bureau of Mines has funded the development of an Automated Breathing Metabolic Simulator (ABMS). The ABMS simulates man in all of the breathing and metabolic parameters for monitoring support and resuscitation equipment. For the first time, complete breathing and metabolic simulation are incorporated in the same device. Breathing rate, breathing depth, breath velocity contour, oxygen uptake, and carbon dioxide release are all variable over wide ranges, simulating conditions from sleep to hard work with respiratory exchange ratios covering the range of hypoventilation to hyperventilation. In addition, all of these parameters are remotely controlled to facilitate the use of the device in hostile test environments. The exhaled breath is also at body temperature and completely saturated. The simulation in faith¬ful to the extent of having a variable functional residual capacity and an anatomical dead space equivalent to that of humans. The ABMS will be used as a stand-in for humans in test and validation of respiratory equipment, permitting more extensive and safer evaluation in hazardous environments where human testing would have to be limited. In addition, it will greatly reduce the cost of prolonged testing in cases where simulation chambers with human subjects require three shifts of crews, including standby physicians. Perhaps most importantly, it will provide a calculated and reproducible test and validation facility. The ABMS is under complete computer control. Through a typewriter terminal the test sequence can be input into the computer which will then automatically adjust the ABMS to simulate any desired sequence of metabolic activities for time durations up to 15 hours. The computer also monitors the test procedures and provides test results printout.

Jan 1, 1973

By Lloyd Williams

1. This investigation shows that the Poplar Creek is the most important bed in Scott County from a production standpoint. Although the Poplar Creek bed contains the largest reserve, the Big Mary has a larger recoverable reserve. Estimates of reserves also have been made for the Pewee, Red Ash, Windrock, Upper Pioneer, Jellico, and White Oak beds. 2. Known measured and indicated reserves of coal, based on a minimum bed thickness of 14 inches and on 1,800 short tons per acre-foot of coal in place, are estimated to be 143 million tons as of January 1, 1954. Of this total, 74 million tons is in beds 28 inches and more thick. Areas in each bed were omitted from the estimate because available data relative to the bed characteristics are too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1956

By A. B. Hooker

Gassy mines require daily inspections with methane detectors to test for the presence of methane. Although in many manes it may be sufficient to know that there is no methane present or that its percentage is below a certain amount, it is desirable and often necessary to determine definitely the percentage of methane at the working faces and in the various air currents. The Bureau of Mines recognizes two general types of portable methane detectors, namely; 1. Methane detectors by which the presence of methane may be detected and its approximate percentage estimated.

Jan 1, 1929

By E. C. Lane

This paper is the second report of the results of the United States Bureau of Mines twenty-third semiannual survey of motor fuel marketed in the United States. The first paper, reporting data relating to gravity, vapor pressure, and distillation range of the samples, was published as Report of Investigations 31293. A third and concluding paper giving the results of other tests will be published as soon as these tests have been completed. The present paper deals with the data of the twenty-third semiannual survey presented in accordance with the revised specifications for United States Government motor gasoline. The sample numbers used are identical with those used in Report of Investigations 3129, with additional data included for copper strip corrosion (method 530.22),4 and sulphur content by the lamp method. Three hundred and twelve samples were collected and analyzed in this survey. Two hundred and seven samples were competitive-price gasolines and one hundred and five samples were premium-price motor fuels.

Jan 1, 1931

By R. W. Van Dolah, N. E. Hanna, F. C. Gibson

Measures that were taken to eliminate noise resulting from explosives work at the Bureau of Mines facility at Bruceton , Pa . , are described . A method for monitoring sound transmission characteristics of the atmosphere and control of the explosives testing is presented as a noise control measure that offered partial relief during the period in which the modifications were made . Design details of the replacement gallery , used for permissibility testing of explosives , and the modifications of four types of bombproofs are given . Operation of the closed facilities are completely satisfactory , and the noise problem has been entirely eliminated .

Jan 1, 1964

By A. R. Mumford

During the course of an investigation conducted by the fuel section of the Bureau of Mines , on a hand- fired return- tubular boiler plant , it was found that the average cost of fuel to produce 1,000 lb. of steam was $ 0.5287 . Tests conducted after some simple changes had been made in the furnaces , and in the control of the boilers , showed the previous high cost of fuel per 1,000 lb. of steam could be reduced to the reasonable figure of $0.3540 , or the equivalent of over 30 per cent saving in fuel cost .

Mar 1, 1923

By Andrew W. Berg

The Bureau of Mines Mineral Industry Location System (MILS) is part of the computerized Minerals Availability System (MAS), a comprehensive data base of known mineral deposits. MILS, the location subsystem of MAS, has become widely used by the minerals industry and organizations with land-use planning and land management responsibilities. Information on more than 135,000 mineral locations and processing plants in the United States is contained in the data base. This information includes the name, location, mineral commodity, type of operation, bibliography, and cross-references for each property or prospect. Computer-drawn map overlays at various scales showing clustered MILS locations and computer printouts keyed to those overlays are available for inspection and reproduction at the Bureau's Field Operations Centers at Juneau, Alaska, Denver, Colo., Pittsburgh, Pa., and Spokane, Wash.

Jan 1, 1979

By R. V. Lundquist, H. Leitch

The solubility characteristics of three calcium aluminates , 12Ca0 · 7A120½ 3Ca0 A1203 , and 4Ca0 A12 03 Fe2O3 , were determined in water and in solutions of NaOH and Na₂ CO₂ to more clearly define their role in relation to the recovery of aluminum by the lime sinter and the lime - soda sinter processes . The calcium aluminates were prepared by sintering stoichiometric mixtures of CaCO3 , Al2O3 3H20, and Fe 0 at 1,375 ° C. The rates and extent of aluminum extractions were determined . The aluminum extractions from the aluminates were dependent on the presence of carbonate ions in the leach solutions , temperature , time , leach solution composition , and solid - liquid ratio of the slurry . The aluminum extracted from the calcium aluminates in water and in NaOH solutions varied from 4.6 to 22.9 percent . Virtually , complete extraction could generally be obtained for 12Ca0.7A120 and 4Ca0.A12 03 • Fe₂ 03 ; in one instance it was obtained for 3Ca0.A1203 , when an excess of carbonate ions was present over that required for the conversion of all of the calcium in the aluminates into CaCO3 . In some cases of poor aluminum recoveries , extractions could be improved by regrinding and releaching the solid residues .

Jan 1, 1964

By H. F. Yancey

This report, dealing with the separation of coal from its associated impurities by means of a pulsater-type jig, continues the series of reports that have been issued by the Bureau of Mines, in which detailed study has been made of the efficiency and mechanism of separating coal and impurities in various coal-cleaning appliances. The previous reports have dealt with the piston jig, coal-washing table, pneumatic table, and Baum-type jig. Such studies of the separation accomplished by any form of concentration device are essential and necessarily preliminary to any intelligent attempt to improve the performance of such equipment Object and Plan The pulsator-type jig was developed recently by G. A. Vissac. Although two articles(2) describing plants using this typo of cleaning unit appeared in 1936, both dealt principally with plant design and layout rather than with plant performance The object of the stork described in this report was to determine the efficiency of the separation made by the pulsator jig on a sized feed, the specific gravity at which the separation between coal and impurity was effected, and the influence of the specific-gravity composition of the coal on the character of the separation made.

Jan 1, 1938

By H. F. Yancey

This report, dealing with the separation of coal from its associated impurities by means of a pulsator-type jig, continues the series of reports that have been issued by the Bureau of Mines, in which detailed study has been made of the efficiency and mechanism of separating coal and impurities in various coal-cleaning appliances. The previous reports have dealt with the piston jig, coal-washing table, pneumatic table, and Baum-type jig.5/ Such studies of the separation accomplished by any form of concentration device are essential and necessarily preliminary to any intelligent attempt to improve the performance of such equipment Object and Plan The pulsator-type jig was developed recently by G. A. Vissac. Although two articles(2) describing plants using this type of cleaning unit appeared in 1936, both dealt principally with plant design and layout rather than with plant performance The object of the stork described in this report was to determine the efficiency of the separation made by the pulsator jig on a sized feed, the specific gravity at which the separation between coal and impurity was effected, and the influence of the specific-gravity composition of the coal on the character of the separation made.

Jan 1, 1938

By A. Livingston

This paper on mining practice at the Fresnillo silver mines is one of a series being prepared by the Bureau of Mines on mining practices, methods, and costs in the various mining districts of North America. Two classes of ore are produced at Fresnillo. A low-grade oxidized silver ore; end a complex-base sulphide are containing gold, silver, lead, zinc, and copper. This paper is confined to a discussion of operations relating to the production of oxidized silver ores. To date, more than 10 Million tons of this ore rave been mined. The present (June, 1931) daily production is 2,000 tons of ore, and approximately 600 men are employed in the mining operations.

Jan 1, 1932

By Frederick Bloetscher

An improved parachute-type stopping for changing the course of mine ventilation air during mine emergencies has been developed by Goodyear Aerospace Corporation for The Bureau of Mines. The stopping can be quickly deployed by one man from a single attachment point and provides excellent stopping performance with the flow in the design direction. Adding pin and foam attachments between its skirt and the passage-way surfaces improves its performance with flow in the design direction and maintains the stopping with zero or reverse air flows. Stopping performance results for a range of airway sizes including 7.5 X 10 ft simulated airway with pressure differentials of up to 3.0 inches of water are presented. Predicted performance values for this stopping design for larger passageways are also presented.

Jan 1, 1977

By W. W. Roepke

The linear cutting system, developed by the U.S. Bureau of Mines, uses geometric principles developed by Cardan to produce a nearly constant cut depth. The new system has been extensively tested in a synthetic material under laboratory conditions to verify mechanical capability and to identify operational characteristics. Comparisons between 15-rpm linear cutting and 50-rpm rotary cutting systems show significant improvement in respirable dust entrainment, product size distribution, and energy usage. Respirable dust is reduced by as much as 90 pct. Recovered product showed a 67-pct reduction in -0.32-cm (-1/8-in) material and a 200-pct increase in +5.08 cm (+2 in) material. Average power was reduced by 66 pct for the linear cutting. Because the bit cutting paths differ between linear and rotary cutting, it was necessary to compare the two at the same cut depths and bit types. These comparisons show that low revolution per minute rotary cutting entrains about the same amount of respirable dust as the linear cutting system, but the average shaft torque may be 55 to 130 pct greater for the rotary system.

Jan 1, 2010

By Phillip N. Yasnowsky

"In this Bureau of Mines report, the Federal income tax treatment of mineral exploration and development expenditures is summarized, and changes in the tax treatment of these expenditures since 1951 are detailed and analyzed. Although no attempt is made to establish causal relationships, major tax changes favorable to exploration and development activities did occur in 1951 and 1966 when the Nation was engaged in military actions and the economy was expanding. More recent changes have been unfavorable to exploration and development and were parts of major tax reform efforts. INTRODUCTIONThis Bureau of Mines report discusses the Federal tax law provisions relating to mineral exploration and development expenditures. These provisions, contained mainly in sections 616 and 617 of the Internal Revenue Code of 1954 (Title 26 of the U.S. Code), apply specifically to minerals (other than oil and gas), and thus are of interest to the Bureau of Mines.Bureau of Mines involvement in this subject stems from the legislative mandate in the 1913 amendments to the Organic Act of 1910 (the Act creating the Bureau) to conduct economic investigations of the mineral industries. Congressional concern with the financial conditions in the economic and mineral industries was expressed more recently in the Mining and Minerals Policy Act of 1970 and in the National Materials and Minerals Policy, Research, and Development Act of 1980. The General Accounting Office recommended in 1976 that the Department of the Interior ""identify and evaluate laws and agency programs that affect maintaining and developing a sound and stable domestic mining and minerals industry"" (17, p. iii). 2Taxes, a source of revenue to governments, are a cost to private firms. Thus, taxes directly affect private sector profits, and unique tax provisions are designed to encourage (or discourage) activities such as agriculture, construction, or mining. Even the international competitiveness of the domestic mineral industries may be affected by taxes because many minerals are traded in world markets."

Jan 1, 1985

By McElroy. G. E.

"INTRODUCTION The ventilation of development faces in mines for diluting gas or dust concentrations and, in hot mines for providing air-motion cooling effect, by fan pipe units discharging high-velocity streams of air close to the face, is an important phase of mine ventilation. The effectiveness of such units depends largely on the air-flow distribution between the pipe discharge and the face, a subject on which little definite information is available. A study of the air flow from grills into rooms 3/ has provided some basic data, but under conditions no different from mine fan-pipe installations in development ends that the data are of doubtful application to mine installations, owing to differences in air-flow conditions.The purpose of this report is to present and discuss the results of an initial series of tests of a general investigation designed to yield definite laws and design data for the discharge of fan-pipe lines in mines. This series was planned to yield preliminary data on the effects of velocity of discharge, size and shape of pipe, and adjacent walls on the air-flow distribution. Tents were made on 10-inch pine with seven different end conditions and one change of wall condition. Changes in size and shape of discharge wore made by short transformation pieces directly at the discharge end, with the result that effects due to contraction and expansion of the flow, which proved to be of much greater importance than was expected, totally obscured any normal effects due to size and shape. The results of this series of tests, therefore, relate to 10-inch pipe with various discharge designs and are so reported."

Aug 1, 1940

By Gregory J. Chekan

The Bureau of Mines, in an effort to improve planning and development in coal mining, is investigating strata interactions associated with mining of multiple coalbeds. Two common interactions that occur between adjacent coalbeds are subsidence and pillar load transfer. The study described involves underground observations and measurements conducted at two Pennsylvania mines, each affected by one of these interactions. At the mine affected by subsidence, measurements show that undermining had little effect on upper mine pillar stability, but had a more severe effect on the development and maintenance of entries. Roof-to-floor measurements recorded over four times more convergence in entries developed over gob as compared with entries developed over support pillars in the lower mine. At the mine affected by pillar load transfer, Initial in situ measurements have shown the existence of a pressure arch in the lower workings. Prior research has shown that arch interaction between two adjacent openings can create stress concentrations in the in-nerburden. Underground measurements and results obtained from both mine sites correlate with theoretical and photoelastic multiple-seam models, and eventually these field data will serve to refine model accuracy. Further study of multiple-seam interaction mechanisms will lead to improved mine planning, increased resource conservation, and a safer working environment.

Jan 1, 1986

By H. B. Humphrey, F. E. Cash

The Southern Appalachian coal field extends southward across Tennessee in a belt about 50 miles wide between the eastern and middle sections of the State. The earliest record of the production of coal in Tennessee is for 1840, and the first inspection laws were passed in 1881. In 1887, a second act of the legislature created the office of Chief Inspector, but little was done until 1891 when a new act was passed giving to the Department of Mines added duties and powers. Since that time, except for the years 1915 to 1918, com¬ prehensive annual reports have been published. Data for the tables given in this paper are taken from these annual reports, from those of the Southern Appalachian Coal Operators' Association, and from the publications of the United States Bureau of Mines, which has main¬ tained a station at Jellico, Tenn., since 1911. Complete figures for 1930 are not available yet and they are not included in the averages. The State Department of Mines, the operating companies, and the United States Bureau of Mines cooperate in accident-prevention work. It is the purpose of this report to present in uniform tables the available statistics in regard to fatal accidents in Tennessee and in the coal mines of the United States, in order that the progress in mine safety in Tennessee may be compared with that of the country as a whole, and the present period may be compared with various periods of the past, to indicate the main points of attack in the reduction of accidents.

Sep 1, 1931

The realization that there is a limit to our supply of domestic mineral and fuel resources, which have been taken for granted until recently, has stimulated the need for conservation and optimum utilization of the Nation's minerals, metals, and fuels-resources critical to our national economy. The mission of the Bureau of Mines is to develop new technology, improve existing technology, and disseminate information related to mineral resources and industries. Fulfilling the mission is necessary to insure a continuing, adequate supply of minerals and alternative supplies of energy from reliable sources at the lowest possible cost to society and the environment. Established in 1910, the Bureau of Mines under the Department of the Interior is the Federal Government's primary research arm in the mineral field. Since the transfer of the fossil fuels portion of the energy research program to the newly organized Energy Research and Development Administration (ERDA) in fiscal year 1975, Bureau research has been concentrated on increasing mineral production, decreasing energy usage through more efficient processing, and decreasing material losses caused by corrosion. Concurrently, research is being addressed to improved coal-preparation techniques, especially to expanding utilization of low-grade coals and coals difficult to beneficiate, which are essential for reducing the need for petroleum and natural gas supplies and for redirecting our energy consumption. Fluctuations in the availability of foreign sources of minerals, metals, and fuels due to political and economic variability among nations have necessitated intensified investigation into coal mining, uranium-ore processing, and geothermal energy sources-three alternatives that can help to alleviate the dependence of the United States on foreign sources of energy.

Jan 1, 1975