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By H. W. Wainwright

.1. The purification pilot plant and the equipment, solution, and gas cycle used for removing hydrogen sulfide and carbon dioxide are described. 2. As sulfur recovery is necessary in any large Fischer-Tropsch plant, pilot-plant runs were made at 300 p.s.i.g. to study the efficiency of tri-ethanolamine solutions in removing selectively hydrogen sulfide from gases containing varying amounts of carbon dioxide. 3. Aqueous solutions of TEA of 20, 30; 35, and 50 percent were investi¬gated. Data indicate that 30 to 35 percent is the optimum concentration if both selectivity and economy are considered. Slightly better selectivity is obtained with the.20 percent solution, but steam consumption is greater owing to the higher solution rates. Results from our pilot plant runs indicate that a 50 percent solution not only produces an acid gas of lower hydrogen sulfide content but also requires high solution rates to effect hydrogen sulfide purification. 4. Data from 37 runs using TEA are presented in tabular form. In addition, the data are correlated and presented in three sets of curves. By using these curves, it is possible to calculate the compositions of the purified and acid gases for various raw gas mixtures. 5. In cooperation with the Southern Natural Gas Co., investigations were carried out at 300 p.s.i.g. on the simultaneous removal of hydrogen sulfide and carbon dioxide, from gases using various concentrations of diethanolamine. 6. Data from 17 runs employing 20, 30, and 40 percent DEA are reported in both tabular and graphic form. 7. A comparison of the data from one DEA run made at 200 p.s.i.g. with those from the runs operating at 30O p.s.i.g. shows float the absorption capacity of the solution, and, hence, the steam requirements per gallon are about the sage for both pressures. .The only real advantage of the higher pressure is the additional volume of gas that can be treated. 8. The quantity of steam needed to reactivate fouled TEA and DEA solutions increased as the reactivator pressure was increased about 1,0 to 1.1 pounds of steam was required for each gallon of circulating solution when the reactivator was operated at 5 p.s.i.g. 9. A curve is included that shows the effect of the hydrogen sulfide con-centration in a lean 35 percent TEA solution on the hydrogen sulfide content of the purified gas and on steam consumption for reactivation. 10. Both TEA and DEA reduced the organic sulfur content of the raw synthesis gas considerably. Analyses of the lean amine solutions showed a gradual build up of sulfur compounds, indicating that the compounds formed by the amines and organic sulfur do not break down under the ordinary operating conditions of the reactivator. 11. Considerable operating difficulty was encountered in the pilot plant owing to foaming of the amine solutions. Laboratory experiments in which the effectiveness of certain antifoam agents was studied showed Alkaterge C to be most promising for the particular conditions studied.

Jan 1, 1952

By Fred P. Giese

Southeastern reserves of titanium ores are large, widespread, and ample for anticipated demand. The leading titanium industries are mining and beneficiating sand deposits, principally in Florida, and manufacturing titanium pigments. Most of the mineral output is consumed by the producers themselves. In 1962, 20 percent of the national pigment capacity was in the Southeast.

Jan 1, 1964

By Anthony E. Szczuka

The purpose of this design note is to document the data that has been received from manufacturers, coal companies, training centers, government agencies, etc., that pertains to the completion of the Concept Feasibility Study For Training Equipment Designed to Improve Coal Productivity. Revision A documents additional data that has been received. ACKNOWLEDGEMENTS We wish to express our appreciation to the companies, mines, government agencies, unions, and contractor agencies listed herein that furnished the documented data. In most cases, it was furnished willingly and free of charge. In the few cases where the data was purchased, MDEC IRAD funds were used.

Jan 1, 1976

By Paul C. McWilliams

The U.S. Bureau of Mines has, primarily through its contract program, used large-scale centrifuges to determine design criteria for tailing embankments. The centrifuge runs were made at two installations, the University of Cambridge, Cambridge, England and Sandia National Laboratories, Albuquerque, NM. The major problems considered were as follows: slope stability of embankments, modeling erosion and seepage, use of the phreatic surface level to ascertain the validity of centrifuge modeling, and the effects of compaction and weathering on a tailings embankment. This report summarizes the results of the four test series conducted at University of Cambridge and Sandia National Laboratories. A review of prior centrifuge applications to mining problems is included. Consideration is given to future centrifuge application to mining problems in both soil and rock mechanics.

Jan 1, 1989

By William W. Adams

A larger measure of safety attended the operation of the stone quarries and related plants in the United States during the calendar year 1935 than in any other year for which annual records are available for the industry. The accident rate, covering fatalities and nonfatal injuries that disabled an employee beyond the remainder of the day on which the accident occurred, was 38.19 per million man-hours of work performed. The nearest approach to this favorable record was in 1932 when the rate was 38.48. The rate for 1934 was 41.82; hence the record for 1935 was 9 percent better than that for 1934. Reports from operating companies showed that 51 men were killed by accidents in 1935 and 4,152 men were injured. (See table 37.) The industry employed 73,005 men and performed 110,033,341 man-hours of labor, an average of 1,507 hours of work per man. Measured in man-days, the total volume of labor was 14,623,303, or an average of 200 days of 7.52 hours per day for each man employed. These figures are not strictly comparable with similar figures for the preceding year, as the, coverage of the industry was more complete for 1935 than for 1934 because special facilities were available to the Bureau of Mines for conducting the 1935 canvass that were not available for the 1934 canvass. Reports covering identical plants that were active both in 1934 and 1935 indicate a reduction of about 7 percent in the number of men employed in 1935. This fact suggests that the apparent increase in the number of workers in 1935 is attributable chiefly, if not entirely, to the more complete coverage of operating plants in 1935. The plants from which this inference is drawn employed 21,799 men in 1934 compared with 20,248 in 1935.

Jan 1, 1937

By J. L. Holman

The Federal Bureau of Mines has conducted research to delineate factors affecting relative fabricability of electrowon and electrorefined copper. The Bureau's Rolla Metallurgy Research Center coordinated and participated in a statistical round-robin chemical analysis and performed impact tests on lead-doped copper specimens. In a series of round-robin analyses, cathode, bar, or rod from a domestic lot of electrorefined copper and electrowon copper from a domestic and a Peruvian source were analyzed for Pb, Fe, Bi, Se, Ag, O, S, Sb, and seven other elements. The electrowon cathode from both sources surpassed requirements for electrolytic cathode, although lead in the Peruvian lot exceeded specification for oxygen-free electronic grade. The least interlaboratory agreement was for oxygen analysis, Copper specimens, doped with up to ~300 ppm Pb and consisting of as-cast material (fine-grained or coarse-grained) and hot-rolled material, were impact-tested at temperatures to 871° C (1,600° F). Impact energy of fine-grained material dropped 26 pct with increased Pb up to 20 ppm and more gradually thereafter. Coarse-grained specimens fractured at lower energy with little dependence on lead. Hot rolling raised impact energy substantially. Grain structure is evidently as significant as lead in influencing workability. Some discussion is given of possible effects of oxygen, sulfur, and porosity.

Jan 1, 1978

By Philip K. Hopke

A systematic study of the mechanism of interaction of 218Po(RaA) armed by the decay of 222Rn with airborne particulate matter has been made. The rate of attachment of RaA to particles in the diameter range of 0.1 µm to 10.0 µm has been measured as a function of particle size, concentration, and composition, radon concentration, time of interaction, relative humidity and temperature. It was found that under the conditions in these experiments the attachment rate was proportional to the square of the particle diameter and varied with temperature and relative humidity. The composition of the particles apparently has no effect on the attachment. The variation in attachment rate was related to a sticking probability coefficient of approximately 0.02 that varies systematically with temperature and humidity. In addition, the rate of deposition of RaA on the wall of the attachment kinetics system was measured and also found to change with temperature and relative humidity.

Jan 1, 1980

By Kevin Connor

During 1986, the Government continued with efforts to ease the country's almost total reliance on coffee exports for trade revenues by allocating 45% of the Government's budget to commerce and industrial projects. The collapse in coffee prices in 1985 continued to exacerbate the country's growing trade deficit, weakened currency, and dwindling reserves of foreign exchange in 1986. Amoco Burundi Petroleum Corp., a subsidiary of Amoco International Oil Co., continued with plans to drill at least two exploration wells in Lake Tanganyika in 1987. Both offshore and onshore drilling exploration was planned by Amoco Burundi. Any oil or gas finds were expected to have substantial impact on the Burundian economy, as a major portion of the country's trade deficit was directly attributable to petroleum and gas imports.

Jan 1, 1988

By Richard H. Bares

This report describes the purpose and application of seventeen statistical and mathematical procedures used in a series of studies made in the project ?A Systems Approach to the Reclamation of Strip-Mined Areas in North Dakota". The objective is to help readers better understand the utility of these procedures.

Jan 1, 1982

INTRODUCTION The pager phones used in many underground coal mines are battery- operated, party-line telephones with provisions for loudspeaker paging. The system is two-wire, non-polarized, and is operated by self-contained batteries. Many of the individual units are certified as permissible. Requirements for installation are specified in state and federal regulations, such as in the Code of Federal Regulations, Title 30, Mineral Resources, Part 75. The major federal regulations that affect communication in coal mines are noted below, with a brief description of the subject matter in each of the relevant paragraphs. Refer to the cited paragraphs of Title 30 for explicit details of these regulations. (This brief description is for reference purposes only.) Minimum Requirements (paragraphs 75.1600, 75.17 13-2, and 75.1003-1) Approved telephone or two-way communication will be provided between the surface and each main shaft landing and each working section ; to the nearest medical assistance; and shall be protected from contact with trolley wires or trolley feeder wires. Installation Requirements (paragraphs 75.5 16-2, 75.52 1, and 77.508-1 ) Communication wires will be supported on insulated hangers, attached to messenger cables, or buried, to protect against mechanical damage ; installed opposite trolley wires; and insulated near power conductors . . . each cable will have lightning arresters within 100 feet of going below ground . . . and arresters will be provided wherever telephone wires enter a building. Wire and Cable Requirements (paragraphs 75.5 16-2, 75.5 17, and 75.52 1) Communication cable means two or more insulated conductors, covered by an additional abrasion-resistant covering; power wires and cables shall be adequately insulated and fully protected; and lightning arresters shall be connected to low-resistance grounds, more than 25 feet from neutral grounds.

Apr 1, 1975

The strippable reserves of bituminous coal and lignite in the United States were calculated in accordance with the prevailing conditions of seam thickness and depth of overburden in each of the several coal-producing areas of the Nation. Within defined limits of seam thickness and depth of overburden, it is estimated that there was a remaining strippable resource of 118 billion tons of raw bituminous coal and lignite as of January 1, 1968. Because of topography, natural and manmade features, and other limitations, only 45 billion tons of the resource are strippable reserves. Of this, 32 billion tons is considered low-sulfur (less than 1 percent), 4 billion tons is medium-sulfur (1 to 2 percent), and 9 billion tons is high-sulfur (over 2 percent) coal. Owing to a cleaning loss affecting that portion of strip coal that is mechanically cleaned, the 45 billion tons of strippable reserves are reduced to 39.6 billion tons of marketable coal. A brief discussion is given for each coal-producing State, summarizing past and present production, historical background, and outlook. Appendix A contains reserve data by State, county, seam, and sulfur content. Appendix B contains the general information and requirements necessary to comply with the current strip mining laws covering 20 States.

Jan 1, 1971

By John H. Johnson

Diesel tailpipe CO, C02, NO, and N02 concentrations by the Emissions Measurement Apparatus (EMA) were found to compare satisfactorily with simultaneous concentrations by instruments in the MSHA engine certification laboratory in Bruceton, Pa. The EMA was then applied to the measurement of LHD vehicle diesel tailpipe gases and smoke opacity in the White Pine and Brushy Creek Mines. A general experimental approach was developed by which instruments could be compared for the measurement of diesel exhaust pollutant concentrations in the 1/2 to 5TLV range. The concentrations are changed by varying engine speed, dynamometer load, and the portion of the exhaust which enters the dilution tunnel. Dräger detector tube diluted exhaust CO, CO2, NO, and NO2 measurements were compared with simultaneously taken portable instrument measurements. Diesel exhaust interference inaccuracies were separated from inaccuracies due to detector tube calibration by comparing the instrument readings with both actual detector tube readings and detector tube readings corrected by recalibration of the detector tubes alongside NBS traceable calibration gases. The detector tubes' accuracy was found to be only slightly affected by diesel exhaust interferences and it was concluded that most measure within certification limits established by the National Institute for Occupational Safety and Health. The effects of 2 exhaust system configurations on the pollutant concentrations in a dead-end heading were studied. Both of the configurations exhausted the gases near the roof, directing them toward the crosscut, and both improved the stratification of the air in the heading, due to the bouyancy of the hot exhaust gases. One of the configurations was a pair of Fume Diluters which diluted the exhaust with air by a 10:1 ratio, and the second system was simply a pair of exhaust pipes, bent to direct the exhaust similarly to the fume dilutors. By redirecting the exhaust, the concentration of C02 measured on the LHD vehicle was reduced by as much as 507, in dead-end headings up to 200 ft long. The Fume Diluters showed no improvement over the simple redesign of the exhaust system.

Jan 1, 1980

By H. P. Greenwald

Cooperation between the Bureau of Mines of the United States Department of the Interior and the Safety in Mines Research Board of Great Britain dates from 1924. It has been intimate and has involved exchange of personnel and. equipment as well as information. Correlation of divergent results obtained in large-scale tests of the explosibility3/ of coal dusts made in the respective countries was one of the first problems to be studied. The purpose of this paper is to show to what extent such correlation has been achieved. COMPARISON OF TEST METHODS The first research accomplished Jointly by the two organizations was a comparison of large-scale methods of determining the explosibility of coal dust. Large samples of coal were exchanged and subjected to test in the Bureau's Experimental coal mine and in the Board's steel gallery, 38 inches

Jan 1, 1939

By H. P. Greenwald

Cooperation between the Bureau of Mines of the United States Department of the Interior and the Safety in Mines Research Board of Great Britain dates from 1924. It has been intimate and has involved exchange of personnel and. equipment as well as information. Correlation of divergent results obtained in large-scale tests of the explosibility3/ of coal dusts made in the respective countries was one of the first problems to be studied. The purpose of this paper is to show to what extent such correlation has been achieved. COMPARISON OF TEST METHODS The first research accomplished Jointly by the two organizations was a comparison of large-scale methods of determining the explosibility of coal dust. Large samples of coal were exchanged and subjected to test in the Bureau's Experimental coal mine and in the Board's steel gallery, 38 inches

Jan 1, 1939

By E. L. Litchfield

The electrification of ammonium nitrate-fuel oil (AN-FO) blasting agents by pneumatic loaders is described and discussed. The consequences of the electrification are considered in light of the initiation requirements of electric blasting caps. It is recommended (1) that semiconductive loading tubing be utilized and (2) that the resistivity of the AN-FO be controlled; it is further recommended that the operator (3) test to assure continuity of the electric detonator legwire-bridgewire-legwire circuit prior to insertion of the cap into charge or borehole, (4) keep the legwires shunted but not otherwise connected to ground during loading of the blasting agent into the borehole, (5) assure that the borehole is discharged prior to hooking up the detonator leads, (6) assure that he is himself discharged prior to handling the detonator leads, and (7) assure that the blasting cap leads are never carried to the AN-FO loader. The basis and significance of these recommendations are explained.

Jan 1, 1968

By Thomas M. Barczak

Advancements in support technology have occurred to a large extent because of the demands of the mine operators. Shield supports are no exception. The most notable changes in shield technology in the past decade have been increases in shield capacity and life expectancy, which have increased by a factor of 4 and 7 respectively since the inception of the shield support 25 years ago. The purpose of this paper is to set goals for the future generations of longwall shields. These goals include: (1) 100,000 cycle life expectancy, (2) improved hydraulic diagnostic capability, (3) smart load control with adjustable setting pressure algorithms, (4) composite material design to reduce weight and increase shield width, (5) constant set leg cylinder design, (6) improved joint design to reduce wear and stress, (7) advancements in leg cylinder socket design, and (8) an instrumented shield to measure in-service structural component loading. These design issues will continue to push the envelope in longwall shield technology that has provided the safest and most productive mining system employed in the history of mining. In preparation for this, a historical examination of shield failures is made and recent trends in shield design are evaluated. Design practices to improve structural margins of current designs are also addressed.

The works recorded in this Test Report have been performed by Rade Roncar - Electrotechnical Institute of Zagreb, SFR Yugoslavia in collaboration with Bureau of Mines. The main objective of these investigations was to investigate the possibility of fabrication of thin-walled square enclosures of satisfactory safety factor in accordance with requirements of effective technical regulations. The results and the investigations can be divided in three main fields: - investigations of thin-walled enclosures with the view of determination of pressures causing technological deformations before performing tests in accordance with effective applicable regulations, - finding the safety factor by means of tests of metal-foam pressure vents, - comparison of enclosures with and without pretreatment by technological deformation.

Jan 1, 1987

By Joe Maher

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Jan 1, 1976

Sixteen papers concerned with the technology and utilization of low-rank fossil fuels are presented as the proceedings of the 1973 lignite symposium. This symposium, the seventh in a series of biennial meetings, was cosponsored by the Bureau of Mines and the University of North Dakota.

Jan 1, 1974

By Sheridan J. Rodgers

The quantity and behavior of gases in metal and nonmetal mines were monitored to provide background information on feasibility of incipient fire detection systems. Monitoring was conducted during working and nonworking periods at intake air, return air and working places. Gases generated during diesel operations and shot firing were of particular interest. Gases which were monitored were CU, C02, N0, N02 and S02: submicron particulate concentrations were monitored also. Commercially available instruments were used and included nondispersive infrared, electrochemical and chemiluminescent types. The ratios of the various gases generated during diesel operations and shot firing were similar to those expected from an incipient fire, with the exception of the C02/NOx ratio, which is sufficiently different to be considered for early fire warning. Samples taken near leaking bulkheads showed high C02 levels and low C0 levels, the reverse of anticipated behavior in coal mines.

Jan 1, 1976