Search Documents

By Frederick Bloetscher

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

Jan 1, 1977

By H. B. Hill

The discovery of the Oklahoma City field and its rapid development into one of the major oil-producing districts is an outstanding epoch in the history of the petroleum industry not only of Oklahoma but also of the United States. The relatively great depth to which the wells were drilled and the large initial production of high-gravity oil are of special significance. The field has boon under proration almost from the time that its development began, and many new production problems have developed out of the changed conditions of operation. The discovery well was first tested in December 1928 at a depth of 6,402 feet, with an initial production of 4,847 barrels of 38,5.° A.P.I. gravity oil, and several months later was, completed at a depth of 6,624 feet, The large initial production, the high pressure, and the large gas volume in the different horizons of the discovery well suggested the potential possibilities of gas and oil, production in formations of Pennsylvanian and pre-Pennsylvanian age.

Jan 1, 1933

By Jack L. Henry, Davis E. Traut, L. R. Penner

The Bureau of Mines conducted solvent extraction batch tests to evaluate the usefulness of neodecanoic acid ( NDA) for extracting Co 3+ from ammoniacal leach liquors high in ammonium sulfate . This work is an outgrowth of previous Bureau research in which technology was devised for the recovery of cobalt , nickel , and byproduct copper from domestic laterites . The previously devised technology uses an oxidative ammoniacal sulfate leach to treat the laterite , and nickel and copper are then recovered from the leach solution by solvent extraction and electrowinning . This report deals with the subsequent solvent extraction of cobalt from the nickel - copper raffinate solution . The results showed that about 70 pct of the contained Co 3+ can be extracted batchwise at pH 8 using NDA ( a 10 - carbon - chain highly branched carboxylic acid ) . However , NDA had a solubility of approximately 0.6 to 0.8 g / L in aqueous raffinate following extraction , and this high solubility makes it impractical for use with alkaline solutions that are low in cobalt . In addition , the extracted cobalt species ( predominately cobaltic hexammine ) is not amenable to the electrolytic recovery of cobalt metal because of its extreme stability . This fundamental prob-

Jan 1, 1965

By Charles A. Sorrell

This Bureau of Mines publication reviews the structural characteristics of crystalline phases and phase equilibria data for the system NaC1-KC1-AlC13-NaF-KF-AlF3, which encompasses a large number of molten salt fluxes currently used in aluminum recycling. Its purpose is to provide guidelines for research into the relationships between molten salt compositions and their physical properties, notably vapor pressures, densities, surface tensions, and viscosities, knowledge of which is essential to maximizing fluxing efficiencies and metal recovery and minimizing hazardous emissions and disposal problems. In addition, this report describes experimental determinations of sub-solidus compatibility relationships in the system, which is of the quaternary reciprocal type, containing 12 different stable 4-phase assemblages in the solid state. The compatibility diagram serves to define the important compositional planes across which important changes in properties are likely to occur.

Jan 1, 1986

By F. G. Schwartz

This circular presents the results of a survey of research on jet fuel thermal stability jointly sponsored by the National Petroleum Refiners Association (NPRA), Tulsa, Okla., and the Bureau of Mines. The development of supersonic planes has led to many problems that did not exist in the operation of subsonic aircraft. One of the most important of these is rapid deterioration of the fuel at the high temperatures to which it is subjected. At higher speeds, aerodynamic heating of the airframe imposes severe thermal problems, and conventional techniques of rejecting the heat to the atmosphere become impractical. The fuel is the only material present in sufficient bulk to be used as a heat sink. Thus, the fuel is subjected to aerodynamic heating and also is used to dissipate heat from lubricating oil, hydraulic fluid, electronic equipment, wheel wells, and cabin air. Consequently, the fuels may have to withstand both moderate temperatures for sustained periods in the fuel tanks and higher temperatures for brief periods during transfer from the tanks to the combustion chamber. Because of high temperatures, insoluble residue or gum may form in the fuel and contribute to heat exchanger fouling and to clogging of the fuel manifolds, nozzles, control systems, and other components of the fuel system.

Jan 1, 1962

By A. L. Engel

In previous reports5/ of ore-testing studies, tests made by established methods on typical ores selected as representative of certain mining districts have been described in considerable detail. In addition to established test procedures, such as screen analysis, chemical analysis, microscopical examination of ores and products, sink-and- float separation, gravity concentration, flotation, ,and magnetic separation with or without roasting, it was sometimes necessary to apply other methods, such as leaching, in instances where physical separations were not feasible.

Jan 1, 1940

By A. L. Engel

In previous reports5/ of ore-testing studies, teats made by established methods on typical ores selected as representative of certain mining districts have been described in considerable detail. In addition to established test procedures, such as screen analysis, Chemical analyses, microscopical examination of ores and products, sink-and-float separation, gravity concentration, floatation, and magnetic separation with or without roasting, it was sometimes necessary to apply other methods, such as leaching, in instances where physical separations were not feasible.

Jan 1, 1940

By V. H. Gottschalk, John Grodd, R. S. Dean

"Elemantary ConsiderationsAlthough magnetiem was first discovered in and derives its name from an oxide of iron found in magnesia and called lodestone its pracical uses date from the discoveries of Faraday concerning its relation to the electric current. We may therefore start our discussion of magnetic properties with Faraday's law for relation between induced electromotive force and the change in a magnetic where e is the electromotive force induced in an electric circuit by a unit rate of change of magnetic flux N, H is the intensity of the magnetic field, S is the area enclosed by the circuit, and i an angle between H and the normal to dS. In the simplest case we could use this law to measure the strength of a magnetic field by passing it at a measured rate through a coil of copper wire and determining the,electromotive force. As a matter of practical convenience, it will be simpler to nee the total quantity of electricity produced by a change of magnetic field. For this purpose we may let i denote the strength of the electric current induced by the change of magnetic field in time in a circuit of area a and resistance R. Then the total electric quantity. Q is given. by"

Mar 1, 1934

By Robert J. Evans

Reclamation costs were estimated for 20 coal surface mining operations in the Appalachian and Midwestern Coal Supply Districts (these two districts were divided into three multi-State regions). The cost data were obtained through onsite observations, interviews with mining company personnel, and the authors' cost estimating procedures. The cost data are presented in terms of dollars per acre, dollars per ton of coal produced, and dollars per cubic yard of overburden moved during backfilling. The reclamation process is divided-into three cost categories: Premining planning, backfilling, and revegetation. The average total reclamation costs for the three regions are $2.77 per ton of coal produced and $8,168 per acre. As the result of comparisons of reclamation costs by region, by mining method, by slope, and by size of operation, the most important reclamation cost difference is between area mining methods ($1.73 per ton) and contour mining methods ($3.81 per ton). The Federal Bureau of Mines conducted this study to determine as accurately as possible the actual costs involved with the reclamation of coal surface mined land done in conjunction with active mining operations.

Jan 1, 1975

By Timothy M. Barton

The U.S. Bureau of Mines is conducting research to assess the effectiveness of different chain pillar designs in maintaining gate entry stability. A particular concern is ground control for deep-cover 1ongwalls located at depths in excess of 1,000 ft. The study described in this report was performed in two experimental sections in one longwall headgate section which contained three different pillar designs. Two of the designs used conventional abutment pillars, while the third was a total-yielding pillar system. Both of the test areas were located under 1,800 ft of cover. The purpose of this study was to evaluate the effectiveness of these three pillar designs for gate road stability. As the longwall mined passed the test areas, Bureau engineers monitored entry convergence, roof sag, and changes in roof quality. The study indicated that the all-yield system performed nearly as well as the better of the two abutment pillar systems; but all of the three designs would have failed to provide acceptable stability for second panel mining without considerable artificial support.

Jan 1, 1989

By Charles A. Seitz

This Bureau of Mines report describes a chromatographic method for analyzing impurities in helium that utilizes a helium carrier gas contain-ing 25 to 30 ppm Ne. An example of the effect of trace amounts of nitrogen, methane, and moisture on the detector's response is shown. The added neon in the carrier does away with irregularities of the analysis which were experienced when the carrier contained up to 3 ppm Ne. The addition of 25 to 30 ppm Ne causes a loss of sensitivity, but the re-maining sensitivity is adequate for routine analyses. The high-neon carrier allows positive and more linear responses for eight impurities: neon, hydrogen, argon, oxygen, nitrogen, methane, carbon dioxide, and ethane. Neon concentration levels of 0.02 to 125 ppm in helium carrier gases were studied. The high-neon carrier has been in successful rou-tine use in Bureau of Mines helium facilities since October 1981.

Jan 1, 1985

By Norma R. Golumsic

Gasoline and other liquid fuels may be obtained from coal by direct and indirect hydrogenation.3/ The direct process, usually termed the coal-hydro-genation or the Bergius process, was patented in Germany by F. Bergius in 1914 and developed to a commercial stage by the inventor and I. G. Farben-industrie. From a chemical point of view, the coal-hydrogenation process consists of adding hydrogen to the complex coal molecules and removing oxygen so that its chemical constitution is changed to that of petroleum, whereupon the coal substance liquefies, yielding an aromatic crude oil. In the indirect-hydrogenation process, known as the Fischer-Tropsch process (invented by Franz Fischer and Hans Tropsch in Germany), coal, lignite, or natural gas is first converted to water gas, a mixture of carbon monoxide and hydrogen. This mixture of gases, in proper proportion and after suitable purification, is then passed over a solid catalyst at relatively low pressures (1 to 20 atmospheres) and temperatures ranging from 180° to 260° C. The products obtained are gasoline, Diesel oil, liquefiable gases, and paraffin wax.

Jan 1, 1946

By Jimmie C. Rosenbruch

The Federal Bureau of Mines evaluated the prospects for using geothermal energy to generate electricity for mines in remote areas. Given the development of a geothermal resource for this purpose, the subsidiary uses of space heating and agriculture were then examined to see if other industries might be viable given a cheap source of heat energy. Sites investigated were located in three areas of Alaska: Kobuk in the northwest, Unalaska in the southwest, and Stikine River in the southeast. Each site was relatively close to mineral deposits whose prospects for development would be enhanced with cheap power.

Jan 1, 1975

Objective: On-the-job training (OJT) is a common means of training workers. By definition, it seems relatively simple. However, to be effective, training must go beyond the simple process of following an experienced worker around the workplace— sometimes called the "follow Joe" method. NIOSH researchers spoke with human resources personnel, safety and health specialists, supervisors, experienced miners, and new miners and found that OJT was of high interest, but was rarely part of a formal or standardized program. Various training methods have evolved to ensure that a trainee will absorb the information presented rather than simply emulate what the instructor is teaching. These methods have been brought together into a published guide for developing an effective formalized OJT program. The guide (Information Circular (IC) 9479) is called "Coaching Skills for On-the-Job Trainers." It contains materials and suggestions for your company or mine to conduct a 1-day workshop for teaching OJT trainers how to be better coaches to less experienced workers. The guide was created by the NIOSH Pittsburgh Research Laboratory and a safety professional from a private mining company.

Feb 1, 2006

By J. E. Fraley

This report describes the preliminary results of a Bureau program to develop and test an inexpensive grout for full-column support of roof bolts. Various inorganic grouts were tested in both cartridge and slurry form. Tests were also performed on methods of water packaging and on the effect of fillers on the grout strength. Results showed that some grouts had poor early strength and exceptional mid-to long-term strength. Laboratory tests have shown that rapid-setting inorganic grout could be an economical replacement for resin bolts if the short-term strength could be increased. Further development to improve its early strength would need to be tested in the laboratory and underground to prove its potential for the mining industry.

Jan 1, 1987

By C. M. Palencia

The Bureau of Mines evaluated the potential availability of molybdenum resources from 88 mines and deposits that account for more than 90 pct of the demonstrated resource base in market economy countries (MEC's). For each property, tonnage-cost relationships were developed that indicate the molybdenum potentially available at different average production costs, including a 15-pct rate of return on invested capital. From the 23 MEC primary deposits, 2.5 billion 1b Mo was determined to be potentially available at a price of $411b, rising to 4.7 billion 1b Mo at $8/lb. Copper price-molybdenum tonnage relationships were developed for those mines and deposits from which molybdenum can be recovered as a byproduct of copper production. This analysis showed that another 3.4 billion lb Mo is potentially available based on a copper price of $0.7511b, rising to 4.3 billion lb Mo at $l.00/lb. The United States has been the world's largest molybdenum supplier since 1924. Its remaining resources are sufficient to meet the domestic demand of 57 million lb/yr Mo (averaged for a 10-yr period) through the end of the century. Production from primary domestic mines was suspended during most of 1983 because of oversupply of materials. A major concern is the cheap molybdenum byproducts from foreign copper operations in which employment and the need for hard currency override economics in meeting production goals.

Jan 1, 1985

By Jay W. Hawkins

Under an approved remining program, mine operators can remine abandoned coal mines without assuming legal responsibility for treatment of the previously degraded water, as long as the discharging waters are not further degraded and other regulatory requirements are satisfied. A U.S. Bureau of Mines review of 105 remining permits in Pennsylvania indicates that remining results in substantial reclamation of abandoned mine lands, utilization of significant quantities of coal, and reduction of contaminant loads (acidity and iron) from degraded mine drainage discharges. Normality tests performed on the water quality and flow data indicate generally nonnormal distributions and extreme right-skewness, tending toward lower values. The water quality of underground coal mines was observed to be more highly degraded in terms of acidity, iron, and sulfate than that of surface coal mines. The optimum baseline sampling scenario is 12 months in duration at a frequency of one sample per month. Analysis of water quality and flow rates before and after remining indicates that a majority of the mines exhibited either no change or a significant decrease in pollution rate because of remining. The discharge flow rate was the dominant controlling factor when the post-remining contaminant load was significantly better or worse than the baseline (pre-remining) load.

Jan 1, 2010

By Michael R. Norland

Surface and subsurface stabilization of mining-related wastes through revegetation depends upon the physical, chemical, and biological condition of the waste following mining. Mining disturbances can significantly alter the soil physical, chemical, and biological characteristics of a site, reducing or eliminating mycorrhizal fungi from the soil. Mycorrhizae are economically and ecologically important because they can alleviate environmental stresses caused by lack of proper soil condition and because they are vital to stabilization of mining waste by increasing plant survival and biomass through increased nutrient and water uptake. This report discusses some of the ecological factors that may affect mycorrhizae-plant associations on mining-related wastes and provides general information on mycorrhizae inoculation technology.

Jan 1, 1993

By H. D. Hess

This report describes in detail a unique occurrence of fersmite, (Ca, Ce, Na) (Cb, Ti, Fe, Al)2 (0, OH, F)6, which occurs as small anhedral inclusions and intergrowths with a tantalum-free columbite found in the metamorphic complexes of Ravalli County, Mont. Chemical and crystallographic data along with the physical and optical properties agree in general with those given in the original description of fersmite from the Ural Mountains of Russia. X-ray diffraction data not given in the original description and more specific optical data have been determined. The Montana fersmite, now established as the second occurrence of this rare calcium-columbate mineral, was discovered during a routine Bureau of Mines mineralogical examination of a prospector's sample.

Jan 1, 1960

By K. K. Kelly

METALLURGICAL thermochemistry of titanium is a broad subject and (if data were available) could include a wide variety of topics. The present report is restricted to extractive metallurgy and to substances and reactions that bear upon the magnesium, sodium, and hydrogen-reduction processes employing titanium tetrachloride. The aim has been to present enough data so that the reader not only can check: the calculations for the reactions discussed but also can conduct related calculations if he so desires, without recourse to other compilations of data. The subject matter divides naturally into two parts-the selection of the data to be adopted and the application of these data to pertinent metallurgical reactions.

Jan 1, 1959