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By Felix du Breuil

Contract H0177044 included three objectives; (1) consolidate, maintain, and distribute information on STE approved lighting systems; (2) develop and present one-day seminars on underground mine lighting; (3) determine direct labor and hardware costs associated with the installation of mine illumination systems. All objectives were completed with results as follows: Task I - A file containing 1350 Statements of Test and Evaluation (STE) for all types of underground equipment was developed and publicized throughout the coal fields, A total of 40 requests for STE information was received and processed. Task II and III - A series of 50 seminars was scheduled and presented to 942 attendees throughout the coal fields. The seminars were well received and attendees indicated the information presented would be helpful in bringing their equipment into compliance. Holding a series of seminars in the coal fields, instead of a few in population centers, was favored by attendees. Task IV - Installation cost data obtained on 415 lighting systems indicate that the factors which most affect installation costs are higher hardware cost for DC powered systems and slightly higher manpower requirements for systems installed underground. Based on these data, the total cost to industry of retrofitting existing underground equipment could range up to $50 million.

Jan 1, 1979

By James H. Aase

Shales from 10 locations in Michigan were sampled, tested, and evaluated to determine their suitability as raw materials for producing lightweight aggregate by rotary-kiln methods. Sampling procedures and the geology of the shale units tested are discussed. Preliminary testing in a muffle furnace preceded extensive testing in a l6-inch by 14-foot rotary-kiln. Rotary-kiln products from these shales ranged in weight from 35.5 to 61.2 pounds per cubic foot (pcf). Concrete test specimens made pith selected aggregates were evaluated to determine the qualities of the concrete. Compressive strengths of the concrete ranged from 2,830 to 4,240 psi after 28 days of curing. Unit weight of the concrete ranged from 94.8 to 101.5 pcf. Lightweight aggregate suitable for use in structural concrete meeting ASTM standards was produced by the rotary-kiln method using shale samples from two locations.

Jan 1, 1967

By P. R. Jones

A computer program was written for the design of a shell and tube heat exchanger on a price optimum basis for the following conditions: (1) Triangular pitch; (2) single or multiple pass; (3) heating or cooling; (4) no change in phase; and (5) inside pumping costs immaterial. Price optimum design was obtained for four standard tube sizes and standard pitch. The inside pressure drop was fixed and outside pressure drop was computed for the optimum baffle spacing and when the baffle spacing equaled the shell diameter. Standard shells whose areas equaled or exceeded the required area were also listed. The program was made adaptable to various fluids and to various tube sizes and pitch by reading in many of the required data such as physical properties of the fluids, tube data, and standard shell data in tabular form.

Jan 1, 1968

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

C THRM 1 C CALCULATION OF MINE HEAD LOSSES FROM ALTIMETER SURVEY DATA TURN 2 C PENNSYLVANIA STATE UNIVERSITY - MINERAL ENGINEERING DEPARTMENT THRM 3 C THRM 4 C THRM 5 C THIS PROGRAM CALCULATES PRESSURE LOSSES USING THERMODYNAMIC RELATION- THRM 6 C SHIPS BASED ON POLYTROPIC FLOW BETWEEN STATIONS. FOR REFERENCE SEE THRM 7 C "A NEW TREATMENT OF MINE BAROMETER SURVEYS" BY M. J. MCPHERSON IN THRM 8 C 'THE MINING ENGINEER' NO. 109, VOL. 129, P 23. THRM 9 C THRM 10 C THRM 11 C THRM 12 C IDENTIFICATION OF ARRAYS THRM 13 C NOTE THE PROGRAM HAS BEEN DIMENTIONED FOR FOURTY (40) DATA POINTS THRM 14 C BASEC(6;2) BASE INSTRUMENT TEMPERATURE CORRECTIONS THRM 15 C TRAVC(6,2) TRAVERSE INSTRUMENT TEMPERATURE CORRECTIONS THRM 16 C BASER(I) BASE INSTRUMENT READING THRM 17 C TRAVR(I) TRAVERSE INSTRUMENT READING THRM 18 C TDRY(I) DRY BULB TEMPERATURE AT TRAVERSE STATION THRM 19 C TWET(I) WET BULB TEMPERATURE AT TRAVERSE STATION THRM 20 C ELEV(I) ELEVATION AT TRAVERSE STATION THRM 21 C VEL(I) AIR VELOCITY AT TRAVERSE STATION THRM 22 C TBDRY(I) DRY BULD TEMPERATURE AT BASE STATION THRM 23 C BASC(I) BASE READING CORRECTED FOR INSTRUMENT TEMPERATURE THRM 24 C TRAV(I) TRAVERSE READING CORRECTED FOR INSTRUMENT TEMPERATURE THRM 25 C BBASE(I) TEMPERATURE CORRECTED BASE READING IN BAROMETRIC THRM 26 C PRESSURE THRM 27 C BTRAV(I) TEMPERATURE CORRECTED TRAVERSE READING IN BAROMETRIC THRM 28 C PRESSURE THRM 29 C BTRAVS(I) BAROMETRIC TRAVERSE READING CORRECTED FOR ATMOSPHERIC THRM 30 C CHANGES THRM 31 C RELHUM(I) RELATIVE HUMIDITY THRM 32 C ASW(I) AIR SPECIFIC WEIGHT TURN 33 C R(I) GAS CONSTANT FOR MOIST AIR THRM 34 C STPRES(I) STATIC PRESSURE CHANCE BETWEEN STATIONS (I) AND (1-1) THRM 35 C TOPRES(I) TOTAL PRESSURE CHANCE BETWEEN STATIONS (I) AND (I-1) TURN 36

Jan 1, 1977

By John A. Johnson

For the purpose of comparing the amounts of dust produced by various mining operations, samples of atmospheric dust were collected during a complete cycle of drilling, blasting and mucking at or near the face of the Bureau's Mount Weather testing adit while the efficiency of several types of stemming in metal-mine blasting was being investigated. ACKNOWLEDGMENTS All gas samples were analyzed in the laboratory of the Bureau of Mines Gas Section at Pittsburgh, Pa.

Jan 1, 1939

By A. E. Raddatz

In an attempt to develop technology to use domestic resources in place of imported bauxita, the Bureau of Mines investigated sulfurous acid leaching to extract alumina from kaolin. The process consists of leaching the calcined kaolin with a 30 wt-pct S02 solution at 60° C and 160 psig for 17 hours, fil¬tering the leach slurry, precipitating monobasic aluminum sulfite from the filtrate at 110° C and 60 psig, a& decomposing the sulfite in the spent liq¬uor at 150° C and 55 psig to produce crude alumina. Purification of the crude alumina was accomplished using a modified Bayer process. Results from closed-circuit tests employing the sulfurous acid process showed that overall extraction of alumina from kaolin was 67 pct. Production of 1 ton of alumina would require 3.6 tons of calcined kaolin, 0.7 ton of sul¬fur dioxide, and 8.4 tons of water. After purification by a modified Bayer process, the alumina product contained the following; impurities, expressed in weight-percent: Fa203, 0.009; S, 3.6; Si02, 0.07; Ti02, 0.002; K20, 0.017; and P205, 0.03.

Jan 1, 1981

By Stanley C. Rhoads

The Bureau of Mines investigated the complete ternary system K2 HfF6¬K2ZrF6-l.25 weight-percent HF at 40° C. In addition, solubility curves have been established at 25°, 30°, 500, 60°, and 70° C. These solubility data implemented a study of hafnium enrichment in feed solutions for liquid-liquid extraction processes.. Selected K2HfF6-K2 ZrF6-1.25 weight-percent HF mixtures were equilibrated in a constant temperature bath. Compositions of the equilibrated solutions and wet residues were established from combined hafnium and zirconium oxide and total fluorine analyses. All solubility curves were essentially parallel on triangular coordinates. At 40° C, the solid phase of the K2HfF6-K2ZrF6-1.25 percent HF system is a series of solid solution hydrates with K2HfF6-H20 and K2ZrF6.3H2O segments existing at the respective extremes. Since this system contains K2HfF6-H20 and K2ZrF6.3H20 segments, it is not ideal for simple separation of high-purity K2HfF6 from K2HfF6-K2ZrF6 mixtures by recrystallization. However, it would be useful for producing hafnium-enriched feed solutions from zircon concentrates for liquid-liquid extraction of hafnium from zirconium.

Jan 1, 1973

By W. W. Adams

Lower accident rates were the outstanding feature. of the second annual sand and gravel safety competition conducted in 1930 by the United States Bureau of Mines in cooperation with the National Sand and' Gravel Association. Both the frequency and, severity rates for accidents were greatly reduced as compared with those shown by the first year's contest, that for 1929. Three times as many plants were enrolled, and the number of man-hours of work represented was more than doubled. Seventy-six sand-and-gravel plants, situated in 20 States, participated in the Competition, as compared with 26 plants, located in 13 States, in the year before. The number of man-hours of employment, which indicated the amount of exposure to occupational hazards, was 4,915,592, an increase of more than 100 per cent over the previous year's total of 2,259,572 hours. The frequency of accidents declined from 74.4 per million hours for all plants enrolled in the first year's contest to 42.7 per million man-hours for all plants enrolled in 1930. The accident-severity rate was reduced from 9.7 days of disability per thousand man-hours of exposure in 1929 to 5.9 days of disability per thousand man-hours of exposure in 1930. The actual number of accidents reported for 1930 by 76 plants included four deaths and 206 injuries whereas the 26 plants that were enrolled in 1929 reported three fatalities and 165 injuries. Under the rules of the contest all "lost-time" injuries are reported--that is, all injuries that disable an employee for more than the remainder of the day on which the accident occurred. If the employee is physically able to resume his work on the day following the accident, the injury is not classed as a lost-time injury. The contest covered accidents and man-hours worked by all employees at the plant who were employed by the same company, and included work up to the point of delivery of the material directly to consumer or to independent agency of transportation--in other words, to point of relinquishment of control of the material by the producer.

Jan 1, 1931

By D. E. Van Dillen

Seven configurations for panel entries of a longwall coal mine are compared and ranked according to structural stability. These entry configurations are analyzed using three-dimensional finite element modeling The models include large dimensions to minimize boundary effects, elastoplastic constitutive relations, and simulated excavation and construction of support systems. The stability criteria are formulated in a quantitative manner to facilitate the ranking of the entry configurations. These criteria are based on the expected volume of caved rock in the entry openings. The stability ranking is applied to the entry excavation phase, the headgate phase, and the tailate phase of the entry life cycle. Parametric variations are applied using two-dimensional finite element models to determine the sensitivity to changes in mining and design parameters.

Jan 1, 1981

By E. H. Illsley

This bibliography is the first report of a Bureau of Mines research project on thermoelectric materials. Interest in such research has increased because of recent success in the design of commercial products, including generators and refrigerators, using the principles of thermoelectricity. This success made possible by the discovery of semiconductors that have much higher [effincies] than the metals and alloys formerly studied. Thermoelectricity is a term that includes a large number of phenomena relating heat to electrical energy. However, the moat important applications arise from two effects discovered by Seebeck in 1822 and by Peltier in 1834. When pieces of two unlike materials are joined at their two ends to form a continuous circuit, both of these effects may be observed. If the two junctions are maintained at different temperatures, an electromotive force known as the Seebeck voltage is generated. If, on the other hand, a current is made to flow through the circuit, the junctions of the materials will be found to differ in temperature. This phenomenon is called the Peltier effect.

Jan 1, 1959

By John S. Ball

[A system of analysis for sulfur groups in petroleum distillates has been developed as one phase of the Bureau-of Mines investigation of the more economic utilization of the so-called "black oils" of Wyoming. This problem is being studied by the Bureau of Mines under a cooperative agreement with the University of Wyoming at the Bureau's Petroleum Experiment Station , Laramie, Wyo. Wyoming black oils have high sulfur and asphalt content and usually yield only small percentages of straight-run gasoline. A more detailed description of the properties of black oils has been given in a previous publication (3)3/. The preparation and properties of asphalts from those oils have been described (1, 2), and the effect of thermal cracking and the use of ordinary methods of treating wore discussed in one Bureau publication (4), Although these studies gave considerable insight into the properties and characteristics of black- oils; it was thought t that a more fundamental attack would assist-materially in, the problem of sulfur removal.]

Jan 1, 1941

By John S. Ball

[A system of analysis for sulfur groups in petroleum distillates has been developed as one phase of the Bureau-of Nines investigation of the more economic utilization of the so-called "black oils" of Wyoming,. This problem is being studied by the Bureau of Nines under a cooperative agreement with the University of Wyoming at the Bureau's Petroleum Experiment Station, Laramie, Wyo. Wyoming black oils have high sulfur and asphalt content and usually yield only small percentages of straight-run gasoline. A more detailed description of the properties of black oilshas been given in a previous publication (3)3/. The preparation and properties of asphalts from those oils have been described (1, 2), end the effect of thermal cracking and the use of ordinary methods of treating wore discussed in one Bureau publication (4), Although these studies gave considerable insight into the properties and characteristics of black oil, it was thought t that a more fundamental attack would assist materially in the problem of sulfur removal.]

Jan 1, 1941

By W. H. Ode, W. A. Selvig

Briefly, this swelling test consists in heating 1 gram of pulverized coal in a silica crucible over a gas flame under prescribed conditions to form a coke button which is compared in size and shape with a series of standard profiles numbered 1 to 9. These profiles are intended to cover the size and shape of buttons obtained from coals covering a wide range in plastic properties. The number of the standard profile with which the maximum cross-sectional area of the button most nearly corresponds is recorded as the swelling index. Although the swelling test showed poor relationships with the various tests that were used for measuring expansion or contraction of coal during carbonization, it gave indications of having value in measuring free-swelling and coking properties of coals when burned on fuel tests. An opportunity to investigate this occurred when an engineering company reported pronounced differences in burning characteristics on grates of various shipments of Pocahontas coal. Some of these coals gave trouble by swelling excessively and clogging the grate. Samples were obtained, and it was found that the troublesome coals gave radically higher free-swelling numbers than did the coals that performed satisfactorily. Also, it was found that the free-swelling index test gave better differentiation between coals than could be obtained from the coke buttons from the standard volatile-matter test or iron agglutination-value results. The results of the free-swelling test were confirmed by the Subcommittee on Plasticity and Swelling, Coal, a special group of the Subcommittee, under the chairmanship of R.A. Shuman, worked along with the test method. Estberg, Limacher, and Shuman of the Battelle Memorial Institute investigated the various factors affecting the test and found that the swelling index was a good indication of the suitability of coal for performance on residential-type stokers from the swelling characteristics of the coal. Data were presented that also showed that the index was helpful in the selection of coal for industrial underfeed stokers.

Feb 1, 1948

By John M. Devine

The severe corrosion of equipment that is caused by the presence of hydrogen sulphide in oil and gas has been described in detail by several authors. Such corrosion, termed "low-temperature hydrogen sulphide corrosion", presents a somewhat different problem from the "high-temperature hydrogen sulphide corrosion" that is encountered in refinery operation and which has been described by various-investigators of refinery corrosion.

Jan 1, 1932

By Richard A. Winters

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied 49,875 acres of the 54,833-acre Big Jacks Creek Wilderness Study Area (ID-111-7C) in order to evaluate the mineral resources. The study area is located in Owyhee County, ID, about 15 miles southwest from Bruneau, ID. No mining districts are in the study area, but part of one placer claim, located in 1924, extended into it. The northern portion of the area was covered by oil and gas lease applications; all were cancelled prior to 1985. No economic concentrations of minerals were found in the study area. INTRODUCTION This report describes the USBM (U.S. Bureau of Mines) portion of a cooperative study with the USGS (U.S. Geological Survey) to evaluate mineral resources and potential of the Big Jacks Creek study area at the request of the BLM (U.S. Bureau of Land Management). The USBM examines individual mines, prospects, claims, and mineralized zones, and evaluates identified mineral and energy resources. The USGS evaluates potential for undiscovered resources based on areal geological, geochemical, and geophysical surveys. Results of the investigations will be used to help determine the suitability of the study area for inclusion into the National Wilderness Preservation System. Although the immediate goal of this and other USBM mineral surveys is to provide data for the President, Congress, government agencies, and the public for land-use decisions, the long-term objective is to ensure the Nation has an adequate and dependable supply of minerals at a reasonable cost.

Jan 1, 1986

By A. Renton Amell

The rate of dissolution of U02 was measured in acid solutions similar to those used for in situ leaching, with S04 of 10-1.82 to 10-4 M, Fe(III) of 10-2 to 10-4 M and pH's of 1.1 to 2.3. The dependence of dissolution rate on pH was small and inconsistent, probably reflecting the combined effects of a very weakly polar oxidizing complex, probably FeSO4+, and a nearly neutral U02 surface. Differences in the state of the U02 surface may explain this variability as well as contrasts between these results and results reported in other work. Changing either S04 or Fe(III) concentrations significantly affects dissolution rates. Increasing low sulfate concentrations in solutions containing 10 2 M Fe(III) at pH 2 results in formation of FeSO4+. In such solutions, rates increased with (S04)/(Fe(III)) up to 1:30, thereby indicating that the oxidation of U02 by FeSO4 is more rapid than by Fe3+. However, the dissolution rate decreased at higher (SO4)/ (Fe(III)), due either to sorption of SO42- on the UO2 surface or to formation of other less reactive sulfate complexes such as Fe(S04)2 or FeHSO4+ However, Fe(III) concentration is the dominant factor in determining solution rates. The rate was directly proportional to ferric iron concentration, indicating that the rate-determining step of the dissolution reaction is a single-electron oxidation by a ferric complex. Dissolution rates were lower in solutions of 0.1 and 1.0% H202 (0.029 and 0.29 M) than at similar concentrations of ferric iron because of formation of an insoluble surface coating of uranium peroxide, UO4?4H20. This phase may limit the value of hydrogen peroxide as an oxidant in lixiviants, not only by its very low solubility, but perhaps also by filling pores and reducing permeability in the ore body.

Jan 1, 1978

By William M. Schafer

Forage plots were established on agricultural lands contaminated by acid mining waste. The acid produced through oxidation of pyrite and other sulfides caused elevated solubility and plant availability of copper, zinc, and arsenic which killed vegetation and polluted surface and groundwater. Soil amendments including agricultural lime (CaCO3), hydrated lime (Ca(OH)2), phosphorus, and organic matter were used to reduce the toxicity of metals. Several acid-tolerant grasses were used to vegetate the amended soils. Various soil extraction techniques were used to see which best correlated with vegetation performance. The extractions corresponded to three "forms" of metals in soil including soluble (water-saturation extract); plant-available/weakly adsorbed (DTPA extract); and total (HNO3/H202 extract). Of the extractants tested the DTPA levels appeared to correlate best with metal levels in plant tissue. The DTPA soil extractant serves as a useful tool in predicting potential phytotoxicity of mine waste materials.

Jan 1, 1989

By Roy T. Sorensen

As part of its mission to maintain an adequate supply of minerals to meet national needs and maximize mineral production from domestic sources, the Bureau of Mines is investigating the recovery of alumina by hydrochloric acid leaching of kaolinitic clay. Most iron impurities are leached from the clay along with the alumina and must be removed before or during crystallization to aluminum chloride hexahydrate. The thermal decomposition step then provides an alumina product of acceptable iron analysis. Miniplant studies of a Bureau-developed solvent extraction technique, using a tertiary amine in kerosene diluent, have demonstrated that the iron content in aluminum chloride leach liquors can be reduced to levels of less than 0.007 wt-pct (7 ppm), expressed as Fe203. Entrained and dissolved organic matter in the purified pregnant leach liquor from the solvent extraction circuit can be reduced to less than 2 ppm by using a fabric-packed coalescer and subsequent activated carbon treatment. Investigators discovered that a steady buildup of zinc accumulated in the solvent phase within the extraction circuit, proportional to the amount of leach liquor treated. The solvent phase zinc analysis increased by 0.01 wt-pct ZnO for each 1,000 gal of pregnant leach liquor purified.

Jan 1, 1981

By C. B. Davison

One goal of the Bureau of Mines is to conserve the Nation's mineral resources by developing improved performance materials. Consistent with this goal, the Bureau conducted studies on the formation of undesirable cristobalite in seven different fire clays used as refractories. The studies employed scanning electron micrography, chemical and X-ray analyses, and pyrometric cone equivalent determinations to examine the sample clays and determine the effect of thermal history and stablilizing additives on the amount of cristobalite in various calcines. This research has indicated that as fire clay calcining temperatures increased from 1390° to 1,490° C there was a gradual decrease in the percent of cristobalite present in the calcines and a progressive development of mullite crystallization. No cristobalite was found in fire clays calcined above 1,550° C, but cristobalite reappeared when the calcines were reheated to temperatures between 1,400° and 1,500° C. The research also revealed that additions of lithium fluoride (LiF) prevented formation of cristobalite in fire clay calcines.

Jan 1, 1979

By Abdurrahman Cetinbas

The periphery of longwall panels in the Pocahontas No.3 coalbed is characterized by a zone of reduced permeability that inhibits the natural drainage of methane. A residual gas pressure of 105 psig was measured after 1 year in an isolated block of coal measuring 340 by 1,100 feet. The buildup of gas pressure within such large blocks causes methane problems during plowing operations. However, natural drainage holes drilled during development have been found to reduce the gas content of the coal in this coalbed by over 90 percent. The effect of water infusion on dust during plowing operations was investigated using existing methane drainage holes. These holes were cleaned of debris and a pipe was grouted into the hole for water infusion of the panel. Both total and respirable dust levels were reduced by 40 to 79 percent. Water infusion of the panel proved more effective than did the use of a plow-mounted spray system.

Jan 1, 1974