Search Documents

By Hanns J. Billmayer

This report, which covers the period from June 15, 1974 to May 30, 1975, describes the work performed in compliance with the requirements of Contract No. H0242065 and modifications 1, 2, and 3 thereto. The purpose of the original contract was to equip the second shuttle car in the Jewell Ridge No. 12 mine, section 6R, with a refined design canopy and seats. In addition, several refinements and improvements were to be designed and installed at the same location on the cutter and the loader. However, during October 1974 in response to a request from the Technical Project Officer, the contract was modified to eliminate all of the cutter and loader tasks and substitute the design, fabrication, and installation of an improved canopy on the no. 2 roof drill in the above mentioned section of the Jewell Ridge No. 12 mine.

Jan 1, 1975

By L. J. Froisland

The U.S. Bureau of Reclamation requested U.S. Bureau of Mines (USBM) assistance in developing design data for moving lead-zinc-gold tailings from their current location without disrupting the existing chemically stable conditions. This report presents results of USBM work in determining (1) the minimum required time to air dry the tailings to approximately 20 pet moisture under various drying conditions both in the laboratory and in the field, (2) the degree of oxidation or reduction that occurs during drying, (3) the effect of lime or cement addition before drying, and (4) the likely equilibrium conditions of the dried tailings after deposition at the new location. The limited number of tests performed by the USBM in the available time frame established trends in oxidation levels but did not provide absolute statistical validity of data values. All data from drying and oxidation testing are included in appendices to this report.

Jan 1, 2010

By Michael Rieber

Among the principal gathering/distribution systems for coal is over-the-road trucking. Where alternative trunk line modes such as barge or rail links are weak or nonexistent, trucks may, particularly for relatively short line hauls, act as substitutes. Their major application, however, appears to be in connection with smaller mines or coal users particularly where terrain problems are significant. Truck use has increased as rail lines have been abandoned or suffered neglect. For example, in 1956 about 38 percent of the coal transported in eastern Kentucky and about 8 percent of the coal moved in western Kentucky went by truck. By 1975, the percentages were almost 77 percent and 26 percent, respectively [4,U-11]. While rail route .limitations and deterioration played a part in the change, increased emphasis on road building, particularly during the 1950's and 1960's, and improved truck load capacity and efficiency were also important.

Jan 1, 1977

By R. D. Eash

The purpose of this research contract was to develop and test a Saran latex modified portland cement concrete lagging to be used as a replacement for wood lagging. The scope of work performed was divided into four phases: Phase I - Engineering Criteria; Phase-! I1 - Design Study; Phase III - Fabrication of Lagging; and Phase IV - Prototype Demonstration Project. Each phase of work was completed and is described in detail in this report. The prototype latex modified concrete lagging developed in this program weighed 52 pounds. When tested in flexure, it supported center point loading of 4500 pounds and under 1/4 point loading it supported loadings of 7000 pounds. Deflections at maximum loading ranged from 1/2 to 1 inch. Maximum deflections exceed 2 inches. The lagging does not exhibit catastrophic failure. Two hundred and twenty of the LMC lagging were produced and shipped to the Bunker Hill Company in Kellogg, Idaho for installation in their mine at the 17 level. The lagging are performing satisfactory after 22 months exposure in the mine.

Jan 1, 1980

By H. C. Fuller, J. H. Jacobs

"Manganese ore from Metals Reserve stock piles at Deming, N. Mex., Cushman, Ark., and Philipsburg, Mont., were processed in the Bureau of Mines pilot plant at Boulder City, Nev., to determine their suitability for the production of electrolytic manganese. Manganese was produced successfully from all of the ores.The ores, crushed and ground to minus 33-mesh, were roasted in a Skinner furnace to reduce the manganese and were then leached with spent electrolyte, from the cells, containing sulfuric acid. Acid-leach extractions of 96 percent on Deming, 89 percent on Cushman, and 97.5 percent on Philipsburg ores were obtained. Neutralization of leaches with ammonia results in the highest manganese extraction; but Cushman and Deming leaches could not be neutralized with ammonia, because the amount required was more than enough to maintain the proper ammonium sulfate concentration. A combination of ammonia and calcine was used. However, ammonia was satisfactory for neutralization of Philipsburg leaches. Sulfuric acid needed for make-up was as follows: Deming, 0.380 pound per pound of manganese extracted when neutralized with ammonia and calcine; Cashman, 0.402 pound per pound of manganese extracted when neutralized with ammonia and calcine; Philipsburg, 0.594 round per pound of manganese extracted when neutralized with ammonia alone.All of the leach slurries settled well enough to be separated and washed in countercurrent thickeners.Impurities were precipitated with hydrogen sulfide and removed by filtration. Cushman ore solution contained only- small amounts of impurities and required 0.055 gram of hydrogen sulfide per liter of solution for purification. Deming and Philipsburg solutions contained large amounts of zinc and required 0.55 and 0.65 gram of hydrogen sulfide per liter of solution, respectively.Electrodeposition was satisfactory on all three ores and current efficiencies of 62 to 66 were obtained.A process for the production of electrolytic manganese has been developed by the Bureau of Mines, first on a laboratory scale4/ and then on a semicommercial pilot-plant scale.5/ At first the- pilot plant operated on ore from the Three Kids mine near Las Vegas, Nev., to determine the practical features of the process on ore of this type. Since completing the work on this ore, the pilot plant has been used for processing other domestic ores to obtain engineering data and other economic information regarding the amenability of such ores to the process."

Sep 1, 1946

By Travis Q. Lyday

During 1983, Ecuador's gross domestic product (GDP) decreased by a reported 3.3% in real terms, the second consecutive decline in the economy after more than a decade of growth generated mainly by petroleum export revenues. The slowdown was due, in part, to the effects of the world recession, lower foreign demand for oil, depressed world oil prices, and reduced demand and prices for Ecuador's traditional agricultural exports. Inflation accelerated to an estimated 55% annual rate. The sucre was devalued in March, for the second time in less than a 12-month period, by 27% after remaining unchanged during the previous decade. In addition, continuous adjustments were made every weekday, effectively devaluing the sucre another 30% by yearend. Ecuador's production of crude petroleum increased almost 12% in 1983 compared with that of 1982. Average daily production was 237,100 barrels per day (bbl/d), up from 211,300 bbl/d in 1982.

Jan 1, 1985

By D. V. Keller

Black lung disease, or paeumocomosis, is a serious health hazard for workers working in a coal mine. Though the exact cause of black lung disease is not known, it is certain that prolonged inhalation of fine coal particles, ever present in the mines, does give rise to black lung disease. For a long time, it also has been known that limestone applied to coal dust mine surfaces tends to hold down coal dust thus preventing it from refloating in the air of the coal mines. Since the humidity in the mines may be generally high, this also might be an important factor in the particular substrate system behavior. Fine solid particles stick to other particles and surfaces very indiscriminately. The term adhesion is used for the phenomenon of attachment of particles to surfaces whereas cohesion is used for the phenomenon of attachment of particles to each other. The measurement of the force of adhesion of coal particles to coal substrates presents a great problem, especially in the case of particles in the size range of a few microns. These micron sized particles are at the limit of the resolution of the optical microscope and therefore an electron microscope has to be used for this purpose. The forces of adhesion between these particles and substrate may be very strong and can exceed the weight of the particle by four to five orders of magnitude.

Jan 1, 1973

By E. J. HOFFMAN, J. c. W. FRAZER

The apparatus and methods described in the following pages were devised and used by the writers in connection with certain investiga- tions of the technologic branch of the United States Geological Sur- vey, especially those bearing on the improvement of furnace condi- tions and on efficiency in the use of fuel. The Bureau of Mines, which has charge of such analyses and tests of fuels as were formerly made by the technologic branch of the Sur- vey, is using the same apparatus and methods in connection with similar investigations that are being carried on at the testing plant of the bureau at Pittsburg, Pa. The furnace conditions prevailing both in small plants and in large industrial establishments in this country are frequently far from satisfactory. If such conditions are to be improved, they must be more thoroughly understood, and means must be found to insure complete combustion of the fuel, and yet to permit operation with such an excess of air as will result in the greatest efficiency. In this work the services of the chemist are indispensable. A very important problem is the determination of the small percentage of unburned combustible matter that escapes from the furnace in the flue gases. Under ordinary circumstances so little as 0.1 per cent of unburned combustible matter in a furnace gas is equivalent to about 1 per cent of the fuel used; and for the determination of such small percentages of gas more accurate and refined methods are required than have ordinarily been available heretofore. It is the purpose of this paper to describe some apparatus and methods which have proved satisfactory to those engaged in the chemical work of the investigations mentioned. While these methods and apparatus have been designed more particularly with regard to analysis of furnace gases, their use is by no means limited to that purpose. The reader will readily see their applicability to other uses in which the sampling and analysis of gases are involved.

Jan 1, 1911

By Robert Stefanko

Test procedures for evaluating underground coal mine trailing cable splices are formulated. The tests are utilized to evaluate several trailing cable splices. The laboratory results are compared with actual field observations and experience. The results are utilized to define quantitatively the generalized terms of the 1969 Health and Safety Act. Recommended specifications and procedures for testing by MESA Department of Approval and Testing personnel are included. Failure points in splices are detailed and presented for use by a MESA training program and manufacturers attempting to improve product quality.

Jan 1, 1974

By Don Conrad, Tom Friend, Bill Wiehagen, Lynn Rethi

On-the-job training (OJT) is a very common method of teaching job skills. Much of the training is done by experienced workers. This paper discusses small investments that can help improve the effectiveness of OJT. Effective OJT involves some structure and planning in the transfer of responsibility for task performance from the trainer to the novice. Assisting the OJT trainer could involve helping develop up-to-date job analyses and offering strategies for teaching and evaluating job skills. The scope of this paper addresses (1) organizational considerations supporting structured OJT, (2) general strategies for structuring OJT, (3) a typical approach for conducting OJT, (4) characteristics and duties of OJT trainers, and (5) limitations of OJT as a teaching method. Health, safety, and operational skills can be connected through training. Haul truck operator training is used to illustrate some of the concepts discussed in this paper.

Jan 1, 2002

By Joseph M. Pugliese

This work was done by the Bureau of Mines to provide quarry operators with an uncomplicated, first-approximation method for designing blast patterns, considering geologic structure, and to show the valid use of the technique by comparing drill and blast pattern dimensions used in the quarry with those determined by the presented method. The author visited 12 limestone and dolomite quarries in Ohio (Adam, Crawford, and Highland Counties), Wisconsin (Milwaukee, Racine, and Waukesha Counties), and Minnesota (Fillmore, Olmsted, and Wabasha Counties); observed the blasting practices; studied the major geologic features; and after discussion with the quarry managers, foremen, and blasters, compared the quarry blasting patterns with those as calculated by the empirical formulas (after R. L. Ash), with geologic structural considerations. When geologic structure such as bedding, jointing, folding, and caves, as well as explosive properties and field performance characteristics are accounted for in a manner suggested by the research, the presented empirical formulas may be used as a good first approximation. The included steps in planning a blast design and generalized blast patterns should be of help to the quarry operator. Design changes are recommended for those quarries where problems are occurring.

Jan 1, 1972

By S. D. Cramer

Corrosion research is being conducted by the Federal Bureau of Mines to determine suitable construction materials for geothermal resource recovery plants. As part of this research, the corrosion resistance of 31 iron-nickel-, aluminum-, copper-, titanium-, and molybdenum-base alloys was characterized and evaluated in laboratory corrosion studies in low-and high-salinity geobrines representative of those found in the Imperial Valley, Calif. General, crevice, pitting, weld, and stress corrosion were measured at 105° and 232° C in deaerated brines and brines containing dissolved 02, C02, and CH4 General corrosion rates in deaerated brines at 105° and 232° C were usually below 5 mpy for the alloys tested except carbon steel, the low-alloy steels, Monel 400, 70-30 cupronickel, and the aluminum-base alloys. Dissolving carbon dioxide and methane in the brines at 2320 did not markedly alter these results. However, the introduction of oxygen, which can enter the brine during process operations, seriously degraded the corrosion resistance of many alloys by increasing the incidence of stress corrosion cracking, crevice corrosion and, except for the titanium-base alloys, pitting. In deaerated brine at 2320 C, the general corrosion rates for carbon steel and the low-alloy steels were relatively unaffected by pH in the range of 6.1 to 3.0. However, general corrosion rates increased sharply below pH 3.0. In deaerated brine at 232° C, welds in several iron-, nickel-, and titanium-base alloys corroded at rates comparable to the general corrosion rates of the alloys, but the addition of oxygen to the brine increased corrosion rates for welds in Inconel 625 and E-Brite 26-1. Alloys exhibiting good corrosion resistance in the deaerated Salton Sea KGRA-type brine at 232° C were E-Brite 26-1, Inconel 625, Hastelloy S, Hastelloy G, Hastelloy C-276, TiCode-12, Ti-0.2Pd, Ti-2Ni, Ti-1.7W, and TZM. The alloys most resistant to corrosion in oxygenated Salton Sea KGRA-type brine at 232° C were the titanium-base alloys. These alloys appear the most suitable for use in the construction of geothermal resource recovery plants. Carbon steel and the low-alloy steels are unsatisfactory for high-temperature, high-salinity brines and alternative low-cost materials with improved corrosion resistance should be sought.

Jan 1, 1980

By Martin Hertzberg

The concept of limit burning velocities is being used to formulate a quantitative theory of flammability limits. Competing and complicating processes dissipate power from a combustion wave and quench propagation at some characteristically low limit velocity. Two earlier reports dealt with process (a), natural convection (RI 8127); and with process (b), conductive-convective wall losses (RI 8469). This report considers process (c), radiative losses, and process (d), selective diffusional demixing. The limit burning velocity for radiative losses is [(SU)c ~ e cp] It is normally not a significant process for premixed gas flames; however, for laminar flame propagation in a gravity-free environment, it is the only loss process present. Accordingly, limit velocities at zero gravity should be much lower than on earth, and premixed gases should be flammable over wider composition ranges. For highly emissive dusts, soot, or ash-forming flames, radiative losses are significant even under normal gravity conditions. Selective diffusional demixing is a complication that manifests itself in the form of cellular flame structures and wide gaps in composition between upward and downward propagation limits. It induces a burning velocity shift (?Su)d, causing the flame to behave as though it were richer or leaner than its initial composition, depending on whether the fuel or the oxidizer mole¬cule has the higher diffusivity. A simple pertubation analysis shows that the process generates stable cellular flames whenever [dsu] > 0, where ci is the concentration of the reactant with the higher diffusivity. The same analysis indicates that at the opposite stoichiometry, where [dcu] < 0, laminar structures are stabilized. A simple formula for the diameter of cellular flames is derived, which predicts that dcell should vary inversely with the product of the diffusivity difference Di -DJ, and the burning velocity slope [dc ]. Those predictions are in good agreement with the available data. Buoyancy forces for upward propagation induce flame front curvature, and hence buoyancy and selective diffusion are mutually supportive in upward propagation. Thus large gaps in composition between upward and downward limits are present in those composition domains where cellular flames are stable.

Jan 1, 1981

By R. H. Thompson

Preliminary safe distances for blasting wiring from typical electromagnetic sources are presented. The distances are for underground coal mines and electromagnetic sources in the frequency range below 10 MHz. The distances are based on measurements performed at 3 locations in each of 3 coal mines. The measurement apparatus, measurement procedure, measurement results and the rationale used in the calculation of the safe distances are all described. The safe distances presented are dependent on the measurement results and their interpretation. More measurements are clearly necessary to establish the validity of the suggested distances.

Jan 1, 1985

By Roy C. Bartholomae

This Bureau of Mines report presents the results of a laboratory investigation of coal cutting mechanics and noise. These experiments were performed using linear cutting apparatus that operates over a broad cutting speed range. The influence of several coal cutting parameters on the noise, force, productivity, and specific energy associated with linear cuts was ascertained. Some basic theoretical aspects of coal cutting mechanics and noise generation are discussed, and the results of the laboratory experiments are used to formulate analytical models of the coal cutting forces and noise. The analytical model for coal cutting noise is then generalized to account for the more important effects of rotary cutting. Based on the generalized model, an estimate of the sound pressure level at an operator&apos;s position is made for a typical continuous mining machine. It is concluded that by employing linear rather than rotary cuts, using deeper depths of cut, slower cutting speeds, and more efficient cutting tools, it is possible to reduce the level of coal cutting noise, as well as provide benefits to other important areas of health and safety in underground mining.

Jan 1, 1983

By P. D. Lohn

The objective of this program was to develop nozzle designs to maximize the effective cutting length of a water jet. The results of the theoretical program directly support the Bureau of Mines Borehole Mining Program and their experimental program to improve the rock cutting capability of water jets. The borehole geometry requires turning the flow by 90 degrees and accelerating through the nozzle within a restricted length. Several suggestions for turning the flow are offered. The borehole space limitations constrain nozzle length, to the extent that a standard 13-degree tapered nozzle (6-1/2 degrees half angle) is too long to fit in the borehole, at production flow conditions. The design technique developed is computationally economical and enables examination of a large number of shapes and flow conditions. The nozzle design is based on design criteria of minimization of boundary layer thickness at the nozzle exit and minimization of the possibility of separation and cavitation. Six flow conditions, including pressures to 4500 psi and flow rates to 400 gpm, were examined, Best shapes were determined for all flow conditions. The best shape for a borehole reining application consists of an initial 4th degree polynominal (quartic) at the entrance followed by a straight section with a twenty degree (half-angle) taper at the exit.

Jan 1, 1976

By Robert T. Mann

This paper is one of a series being prepared for and published by the United States Bureau of Mines on the quarrying, crushing, and grinding of limestone for cement manufacture. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total coats. It is recognized that publication of total costs might in many instances cause embarrassment to individual producers, as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of J. B. Thoenen, mining engineer of the Bureau of Mines, in the preparation of this paper.

Jan 1, 1933

By Laurance L. Oden

The Bureau of Mines is developing nickel catalysts for converting synthesis gas derived from coal to synthetic natural gas. The present report describes the relationship between the composition of aluminum-nickel alloys in the composition range NiAl3 to Ni2Al3 equilibrated at 840° C and the properties of catalysts obtained from them. Methanation activity was determined in the temperature range of 300° to 360° C in a flowing gas stream containing 1 pct CO, 8 pct H2, and the remainder He. One part per million of H2S was added to the gas stream at 400° C to evaluate the susceptibility of catalysts to sulfur poisoning. The total surface area was measured by the adsorption of nitrogen at liquid nitrogen temperature, and the active surface area was measured by the adsorption of hydrogen at room temperature. Total surface area and active surface area were found to increase with increasing proportion of aluminum-saturated Ni2Al3 in the precursor alloy, but methanation activity and resistance to poisoning by H2S were nearly constant. However, the methanation activity of the catalyst prepared from stoichiometric Ni2Al3 was less than half that of the other catalysts.

Jan 1, 1978

By Ben E. Lindsly

The study of "bottom-hole samples follows in natural sequence the study of samples obtained under high pressures at the well heads of flowing wells. The principal object of this phase of gas-solubility research, started actively in January, 1930, was to gain a more accurate knowledge of the physical and chemical characteristics of the oil-gas mixtures that exist in natural reservoirs.. In possession of actual data regarding the condition of the oil; the quantity of gas liberated from solution upon dimunition of pressure; and the relative volumetric proportions of gas to oil at various pressures throughout the flow string in a well, it should be possible to predict, with a fair degree of accuracy, That physical changes these mixtures would undergo throughout the life of a pool. Such information not only is important in designing flow strings in flowing Tells but is important also in solving problems relating to pumping efficiency and the power required for pumping. Although certain fundamental data were obtained in the study of samples taken at the well head, "bottom-hole" samples are more representative of subsurface mixtures of oil and gas because they are obtained at reservoir temperatures, and before the oil has had the opportunity of intermingling with extraneous gas; that is, gas which either was not in solution originally, or which was liberated from solution at higher pressure, and later became mixed with the original undissolved gas.

Jan 1, 1933

By Frank M. Vodoklys

This is the final report on Contract H0220049 covering the period from 27 April 1972 to 30 April 1974. The objective of the contract was to develop and evaluate materials and methods to achieve post explosion identification of explosives reliably and economically through the use of phosphor coded grains incorporated into the explosive during its manufacture. A coding system of two spotting phosphors and seven coding phosphors was successfully developed during the execution of the contract. The ability of the coded grains to survive detonation in many different types of explosives was demonstrated and the complete code was extracted from a single 100 micron post-explosion fragment. A method was established for testing grain strength to correlate with field test results and an optical system was designed for extracting the code from the grains. Also in fulfillment of the contract requirements a laboratory method for manufacturing the coded grains was established and ten one-pound samples, each with a different code, were fabricated. Finally, a method was developed for applying a coating of polyethylene to the grains to prevent sensitization of the tagged explosives and the ten one-pound samples were coated and delivered to the Bureau of Mines.

Jan 1, 1974