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By Robert H. Peters

Groundfall accidents have been the leading cause of fatalities in the underground coal mining industry for many years. Statistics from the Mine Safety and Health Administration (MSHA) indicate that approximately half of the victims of these fatal accidents were in an area where no devices had been installed to support the mine roof. This report was prepared by the U.S. Bureau of Mines to provide guidance to operators of underground mines concerning the use of techniques that may help to keep miners from going under unsupported mine roof. The report is divided into two major sections. The first section reviews the findings from several areas of empirical research pertaining to strategies for convincing employees to avoid unsafe acts and/or adopt self-protective behaviors. The strategies are (1) incentives and feedback, (2) disciplinary actions, (3) training (primarily fear communications and behavioral modeling), and (4) nondirective techniques. This literature review has a broad focus and should be helpful in making decisions about how to encourage a wide variety of types of self-protective behaviors. The second major section of the report presents an analysis of each strategy's potential for keeping miners away from unsupported roof.

Jan 1, 1991

By Robert W. Waytulonis

The mining regulations of all 50 States were reviewed by the Bureau of Mines, and those parts pertaining to the use of internal combustion (IC) engines (particularly diesel engines) in underground mines or confined spaces were extracted. Also extracted were subjects associated with the use of IC engines; for example, storage and handling of flammable liquids, maintenance, and ventilation requirements. As the laws now stand, 29 States have specific regulations that affect the operation of diesel engines in underground coal and/or metal and nonmetal mines. The other States have no regulations because either they have no mining activities or they defer to Federal regulations. Six states have regulations expressly prohibiting the use of diesels in underground coal mines. Specific contacts (addresses and phone numbers) precede each State's regulations to facilitate inquiries about regulation revisions and interpretation.

Jan 1, 1981

By A. T. Iannacchione

The Bureau of Mines established geologic factors affecting the mining of the Lower Kittanning coalbed to aid in coalbed minability studies and examined the occurrence of "wants" (places where coal is missing) and types of unstable roof rock strata. Trends established from mapping, including prediction of areas of high methane emissions, were extrapolated to unmined areas. 'Wants' in the coalbed are of two types: Erosional and depositional. Erosional features occur where north-south-trending sand-filled channels cut into the coalbed. Variations in depositional environments have caused the coalbed to "split" into several thinner units. Slickensides, commonly indicative of unstable roof, are adjacent to and on the underside of sandstone channels; they were caused by differential compaction and by soft sediment sliding along the contact between the sandstone and adjacent shale. The frequency of unstable roof also increases where the interval between the Middle and Lower Kittanning coalbed is less than 30 feet. The zones of weakness at the contacts above and below the Middle Kittanning coalbed are the controlling factors for unstable roof in these strata. Methane emissions from the coalbed are controlled primarily by depth, fracture permeability, and rank of coal. Local geologic factors are coalbed thickness, associated rock strata, structure, and proximity to outcrop.

Jan 1, 1979

By Loren R. Anderson

This Volume documents the use of the Cone Penetrometer data analysis computer programs VERT and HORZ. The programs are interactive in that they prompt the user for input data and allow correction and modification to be made. The programs read data from the results of cone penetrometer soundings and convert the data to values of tan ø. Mean, standard deviation, skew, kurtosis, linear trends and autocorralation are computed by the programs.

Jan 1, 1982

By Raja V. Ramani

The recognition that surface mining need not be viewed as a permanent dedication of the land but rather as a temporary non-renewable use in a series of land uses has caused greater emphasis on the re-use of surface-mined lands. In an effort to develop a procedure for evaluating postmining land use potentials, specific mines in various regions of the U.S. have been studied to determine the extent of current mined-land planning and to discover characteristics that are regional in nature. As part of this investigation, the Indian Head Mine, which is located in Mercer County, North Dakota, has been studied. The Indian Head Mine is presently operated by The North American Coal Corporation -Western Division and has been in operation since 1917 under various ownership. The status of current reclamation and postmining land use planning was reviewed. In addition, the relationship between mine planning and public planning in an area impacted by energy development was investigated. Finally, key factors affecting site potential realization for western surface mines have been identified.

Jan 1, 1983

By John C. Cook

This was a study to identify and evaluate known technologies employing electromagnetic resonance phenomena in solid minerals for their identification and assaying, particularly assay logging of exploratory boreholes. A comprehensive literature search and study revealed some little known NMR (nuclear magnetic resonance) techniques developed by Professor G. J. Béné's group at the University of Geneva, Switzerland. These are suitable for use in weak, inhomogeneous magnetic fields. Laboratory NMR tests of numerous U.S. ore minerals showed good identifying signals from phosphates, fluorspar, bauxite, oil shale, and spodumene (lithium) ores, but not from the copper, lead, antimony or manganese ores tested. Use of EPR "signatures" for such ores is suggested. A conceptual design for an NMR assay logging system is proposed.

Jan 1, 1978

By Gene Asai

The Bureau of Mines investigated the caustic extraction of alumina and soda from retorted dawsonite-bearing oil shale, as part of a program to devise technology for treating alternative domestic sources of alumina for the production of aluminum metal. Colorado oil shale yielding 13 pct oil (35 gal/ton) and containing 12 wt-pct dawsonite (representing about 4 pct extractable alumina) was retorted to obtain oil-free (spent) shale Spent shale was leached with dilute NaOH to determine the effect of particle size, retorting temperature, leaching variables, and storage conditions on extraction of alumina and soda and dissolution of impurities. Maximum alumina and soda extractions were obtained by promptly leaching minus 28-mesh spent shale, obtained by retorting raw shale at about 5000 C, with 0.5N NaOH. Under these conditions, dissolution of impurities such as Ca, Fe, Ti, and P was low. Leaching tests were made on spent shale stored for periods of up to 30 days at 0° to 42° C and at 0 to 100 pct relative humidity (RH). These tests indicated that significant reductions in alumina extraction would occur if spent shale were stored in ambient Colorado air under naturally fluctuating temperature and humidity.

Jan 1, 1983

By Marvin L. Whisman

This report describes the preparation of tritium-labeled organic compounds to be used by the Federal Bureau of Mines in studying the role of certain gasoline constituents in gum-forming mechanisms. The gasoline constituents that have been investigated boil within a range of approximately 90 to 230° C. and can be classified as paraffins. naphthenes, olefins, diolefins, monocyclic aromatics, polycyclic aromatics, and organic sulfur, nitrogen,: and oxygen compounds. The technique of Wilzbach has been applied to more than 50 samples. Purification techniques have been developed that accomplish rapid and effective purification as well as removal of labile tritium in a one-step operation. Data are presented to show the rate of exchange between tritium and hydrogen that can be expected for a variety of compounds common to a full-boiling-range gasoline. These values should be useful to other investigators using tracer programs involving tritium labeled compounds.

Jan 1, 1961

The panic bars (and associated linkages and electrical circuitry) that are defined in this document are a machine operator-actuated control for the emergency deenergization of the tram motors on self-propelled, electric and diesel face equipment; including haulage equipment such as shuttle cars. There are nine basic types of panic bars (and several variations) that are recommended in this document, but all of the panic bars are characteristically of the ?fire door? type that is frequently encountered on outside exit doors of many public and some commercial buildings. It is also the intent of the following panic bar designs that, when emergency brakes are added to the face equipment machinery for which they are required, that they be designed and hooked up so that actuation of the panic bar will result in automatic application of the emergency brakes (immediately following the deenergization of the tram motors). The following panic bar design requirements are a restatement of the proposed requirements defined in the Federal Register, requirements cited in "Guidelines for the Design and Installation of Devices for Deenergization of Self -Propelled Electric Face Equipment/Automatic Emergency Brake s II by C. E. Lester and J. D. Greenhalgh of MESA, and Bendix recommendations that were formulated as a result of discussions with personnel at the various machine manufacturers and underground coal mines that we surveyed, discussions with G. L. Judy (our consultant), etc:

Jan 1, 1974

By Clarence Hall, J. J. Rutledge

Many of the fatal accidents in coal mines have resulted from the Explosives used in Use of explosives for breaking down the coal. These accidents have resulted both from the use of explo- sives that were not suitable and from the careless or improper use of suitable explosives. Investigation has shown that one of the commonest causes of dis- astrous explosions in the coal mines in this country has been a blown- out shot of black blasting powder or dynamite. The dangers that attend the use of these explosives were perceived several years ago, and in consequence the attention of powder manufacturers was directed to the production of explosives that would be less liable to ignite inflammable gas or dust. The manufacturers have been so successful in their efforts that it is now possible to obtain explosives which yield much shorter and quicker flames than black blasting powder or dynamite, and hence are much less dangerous to use in fiery or dusty coal mines. of explosives. To find out which of the many grades of short-flame explosives Government tests have the qualities that render an explosive most effective and least dangerous for mining coal, the United States Government established a testing station at Pitts- burgh, Pa., in 1908. This station is now under the charge of the Federal Bureau of Mines. Before the station was opened a state- ment of the requirements that the explosives in question would have to satisfy was drawn up and sent to manufacturers. A number of these sent explosives to be tested, and on May 15, 1909, a list of the explosives that had passed the tests was published. Since that date other brands of explosives have been tested and three more lists have been issued. The latest list, published in Miners' Cir- cular 2, Bureau of Mines, contained the names of no less than 71 explosives that had passed the tests prior to January 1, 1911.

Jan 1, 1912

By John T. Neubert

Between 1988 and 1990, the U.S. Bureau of Mines studied the mineral resources of San Juan National Forest to appraise and determine types and locations of deposits that could be mined economically now and in the foreseeable future. The study included a comprehensive field examination and literature search. Substantial amounts of lead, zinc, copper, gold, and silver have been mined from within the Forest in the La Plata, Rico, Silverton, and Dunton areas. At least one buried 200 million ton stockwork molybdenum deposit occurs in the Rico area. Similar size porphyry copper deposits occur at the surface and about 1,700 feet below the surface in the Bedrock Creek area of the La Plata district. Numerous smaller base-and precious-metal and uranium deposits have been prospected and mined throughout the Forest. Coal, oil, and gas have been or are currently being produced in the western and southern parts of the Forest. Carbon dioxide occurs in the western part of the Forest. Strategic elements occurring within the Forest include platinum, palladium, cadmium, gallium, indium, bismuth, and tellurium; however none of these elements is economically recoverable at present. Several geothermal areas are scattered across the eastern two-thirds of the Forest. Industrial minerals within the Forest include sand and gravel, limestone, and decorative stone.

Jan 1, 1992

By Constantine C. Popoff

This report reviews and analyzes, by a simple analytical and logical reasoning, the conventional methods of reserve computations of mineral deposits described in various domestic and foreign publications. It brings together, formulates, and evaluates the principles underlying interpretation of exploration data; and ties such principles to the proposed classification of methods. The material is discussed in sufficient detail to allow general application.

Jan 1, 1966

By M. R. Yenchek

The U.S. Bureau of Mines designed and constructed sensitive and coordination-free ground-fault relays (GFR's) for use on mine power systems. First, a list of GFR attributes for mine ac utilization applications was compiled. These practical guidelines specified design, construction, transient immunity, reliability, and operating criteria. The time-current characteristics of the ac and dc units, subsequently fabricated, were designed to be below the human electrocution threshold. The significant and highly variable capacitance of high-voltage distribution cables was found to preclude the sensing of ground currents in the milliampere range. However, the coordination-free system developed for high-voltage distribution should enhance safety by significantly decreasing response time to ground faults. Implementation of the sensitive GFR technology in the mining industry has the potential to eliminate the majority of injuries and nearly all the deaths resulting from contact with energized components.

Jan 1, 1990

By Irving Wender

The oxo reaction consists of catalytic conversion of olefins by reacting the olefins with CO and H2 (water gas) to aldehydes that contain one more carbon atom than the starting olefin. The aldehydes are then generally reduced with hydrogen to primary alcohols in a second stage. The two-stage process is called the oxo process. The word "oxo" is derived from the German "oxierung" (ketonization); thus the exact English equivalent of "oxo" is "keto". The oxo process may be applied to nearly all olefins. A wide range of pressures and temperatures may be used in both stages. The pressure range usually employed is 150 to 200 atmosheres. The temperature in the first stage is usually about 140° C. and in the second or hydrogenation stage about 180° C. Although a standard Fischer-Tropsch catalyst may be used for both steps, cheaper catalysts have been utilized to effect hydrogenation of the aldehydes. Most of the information for this, report on the oxo process was gathered from Technical Oil Mission microfilms. T.O.M. Reels 14, 55, and 134 were especially valuable. T.O.M. Report 6 by H. M. Weir was very helpful. Information on the oxo process is scattered throughout documents captured in enemy territory, and the present report does not include all the available data. Some of the information was procured by personal interview. Where, in the body of this report, certain investigators are quoted, the source of the statement is either personal interview or the T.O.M. reports.

Jan 1, 1948

By N. S. Dalal, X. Shi

"Electron spin resonance (ESR) measurements on solutions and isolated powders provide direct evidence for the involvement of Cr(V) species in the reduction of Cr(VI) by NAD(P)H. ESR analysis of an isolated Cr(V)NAD( P)H solid yields 6 11 = 1.9831 and 6.i. = 1.9772, indicating that the unpaired electron occupies the d22 orbital of the Cr(V) ion, with square-pyramidal geometry. Addition of hydrogen peroxide (H2 0 2 ) to the N AD(P)HCr( VI) reaction mixtures suppresses the Cr(V) species and generates hydroxyl (""OH) radicals. The ""OH radicals were detected via ESR spin trapping, employing 5,5-dimethyl-1-pyrroline-N-oxide and a-(4-pyridyl-1- oxide)-N-tert-butylnitrone as spin traps. The dependence of Cr(V) and ""OH radical formation on the H20 2 and Cr(VI) concentrations indicates that the Cr(V) species react with H20 2 to generate the ""OH radicals. Similar results were obtained by using various diols (arabinose, cellobiose, FAD, fructose, glyceraldehyde, ribose, and tartaric acid), a-hydroxycarboxylic acids, and glutathione. Investigations with superoxide dismutase showed no significant participation of 02 in the generation of OH radicals. These results thus indicate that the Cr(V) complexes, produced in the reduction of Cr(VI) by cellular reductants, react with H20 2 to generate ""OH radicals, which might be the initiators of the primary events in the Cr(VI) cytotoxicity.In this paper we report an electron spin resonance (ESR)3 spectroscopic detection of Cr(V) species in the reduction of potassium dichromate, henceforth called Cr(VI), by NAD(P)H and other diols. Also reported here is the detection of the hydroxyl (""OH) radical in the reaction between hydrogen peroxide (H2O 2) and a variety of Cr(V) complexes. This work was undertaken because while the reduction of Cr(VI) to lower oxidation states has been suggested as a key step m the mechanism of Cr(VI) toxicity, mutagenicity, and DNA alteration, the details are not yet clear (1-5).Earlier studies on the mechanism of Cr(VI) reduction in cellular systems include those on the reduction of chromate by microsomes (6-8), rat liver DT-diaphorase (9), and aldehyde oxidase (10). All these studies imply that Cr(VI) can be reduced to Cr(Ill) by cellular constituents. Regarding the mechanism of Cr(Vl) carcinogenicity, Jennette postulated that Cr(V) is the ultimate carcinogenic form of chromium compounds (8). This conclusion has led to many further investigations of the formation of Cr(V) in the reduction of Cr(VI) under biologically relevant conditions (11-33). More recently, however, Kawanishi and co-workers (34) have investigated the mechanism of DNA cleavage induced by Cr(VI) in the presence of H20 2 and have argued that it is not Cr(V) itself that is carcinogenic, but it is the reactive oxygenated species (02, 10 2 , ""OH) (produced by the decomposition of the Crv(02) ¾ - ion) that cause the DNA alteration."

Jan 1, 1990

By J. V. Batty

In the course of the investigation of manganese mineral occurrences in the United States, Bureau of Mines examining engineers collected several lots of ore from the Black Rock, Kramer, and. Morgan-Cromar properties, Tooele and Juab Counties, Utah. Extensive laboratory tests were made to determine the amenability of the ores to standard ore-dressing methods of concentration. The Black Rock claims 1 and 2 are 42 miles northwest of Jericho, Tooele County, Utah. A. J. Huber of Salt Lake City and Ross Rydalch of Tooele, Utah, are the owners. The deposit-is reported to be a definite manganese fissure vein in quartzite along which considerable shearing and cross fracturing have occurred. Laboratory work was conducted on a 2-ton sample of run-of-mine ore procured by a Bureau of Mines examining engineer and two smaller, higher-grade samples submitted by the owners as a result of later development. The Kramer deposit is described as a bed of manganese oxides in quartz. The property is being worked by L. E. Kramer, Tooele, Utah, and is 41 miles northwest of Jericho) Tooele County, Utah, approximately 1 mile north of the Tooele-Juab County line. A 1-ton run-of-mine sample was submitted for testing by the examining engineer.

Jan 1, 1952

By J. L. Reuss

The Bureau of Mines investigated the technical feasibility of smelting copper concentrates containing chalcocite (Cu2S) and native copper using nonpyritic sulfur-bearing materials to aid matte formation. The procedure consisted of combining various proportions of commercial chalcocite concentrate, smelter slag, fluxes, and matte-forming constituents to produce charges of comparable compositions. The mixtures were charged in fire-clay crucibles and smelted in an induction furnace at 1,300° C. The research proved that either sulfur or gypsum can replace pyrite as a matte-forming material, and that gypsum produces an exceptionally high-grade copper matte. The addition of small quantities of metallic iron to the nonpyritic smelting charge furthers the removal of sulfur, improves the recovery of copper, and makes it possible to utilize gypsum as the exclusive flux and matte-forming ingredient, thereby eliminating the necessity of adding limestone.

Jan 1, 1968

By R. J. Kuczynski

The U.S. Bureau of Mines operated a 2,000-g (4.4-lb) batch process development unit for recovering platinum-group metals (PGM) from automobile catalysts. Virgin monolith, used pellet, and used monolith catalyst samples were tested. Leaching twice with 1-pct sodium cyanide (NaCN) solution at 1600 C for 1 h dissolved more than 95 pct of the PGM from virgin catalysts and more than 90 pct from used pellet catalysts. More than 85 pct of the PGM was dissolved from used monolith catalysts when a third autoclave step was added. Solid PGM concentrates containing more than 99.8 pct of the dissolved PGM and analyzing greater than 70 pct PGM were recovered by heating the pregnant leach solutions from virgin catalysts to 2500 C and used catalyst to 2750 C for 1 h. The solution after heating contained less than 0.2 ppm. total cyanide. The virgin residues passed the EPA Extraction Procedure Toxicity Test (EP Tox Test), the EPA Toxicity Characteristic Leaching Procedure (TCLP), and the California Waste Extraction Test (WET) for all elements except Ba. Adding sodium sulfate (Na2S04) to the virgin leach residues reduced the amount of Ba dissolved to an acceptable level. The used leach residues passed the EP Tox Test for all elements but failed the WET and TCLP for Pb.

Jan 1, 2010

By M. J. Kovalik

Lower Sunnyside seam coal from Utah was blended with various proportions of char and high-temperature coke to improve the quality of the coke obtained from carbonizing this coal. The Hanson 5-pound carbonizer was used as a "screening test" for the larger scale Bureau of Mines-American Gas Association (BM-AGA) tests, which were correlated with industrial production. Eighteen carbonization tests were made in the BM-AGA 13-inch retort, with a coal charge of about 90 pounds; the cokes were evaluated by the standard ASTM tumbler test. Carbonization of blends containing char and coke breeze yielded less fissured and blockier cokes of significantly higher ASTM I-inch tumbler indices as compared with the value for the straight Sunnyside coal. It was found that the simultaneous addition of char and coke breeze yielded stronger cokes than that obtained by the addition of either one of these additives. Addition of a small proportion of Pocahontas No. 3 or Sewell coal to an optimum blend improved the resulting coke strength further.

Jan 1, 1969

By D. R. Mathews

Electrorefined vanadium was evaluated with respect to tensile properties and the effects of interstitial contaminants in the temperature range of 77° to 273° K. The yield strength of 18,500 psi and hardness of 63 diamond pyra-mid hardness (DPH) of electrorefined vanadium are approximately equal to that of iodide crystal bar vanadium. The ductile-brittle transition temperature was found to be below 77° K, but with 0.175 weight-percent oxygen or 0.10 weight-percent nitrogen, it increased to between 123° and 190° K. With carbon content up to 0.11 weight-percent, the transition temperature remained below 77° K. The yield strength of the interstitial-containing alloys can be expressed by: au = 7.5 + 480 (pct N) + 290 (pct 0) + 280 (pct C), where au is the upper yield stress in 1,000 psi at 273° K. Profuse deformation twinning occurred in the alloys tested at 77° K. However, twinning could be suppressed by dissolved oxygen or nitrogen in excess of 0.15 and 0.086 weight-percent, respectively. Carbon, even though present in excess of the solubility limit, did not affect twinning.

Jan 1, 1965