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By L. L. Oden

The purpose of this research was to develop a method to remove copper and tin from the magnetic fraction of incinerated municipal refuse, as recovered by the Bureau of Mines pilot plant in College Park, Md. Copper, present in the scrap in a metallic form bonded to ferrous objects, was amenable to leaching in cupric ammonium carbonate solution. Copper levels in small 5-to 10-lb lots of treated scrap were reduced from the initial level, 0.5 to 0.6 pct, to 0.1 to 0.2 pct. Larger lots of scrap (100 lb) were treated less effectively because of poor contact of solution and scrap. Oxidation in the air or in aerated aqueous solution was applied to liberate tin from the dilute solid solution present on the surface of incinerated tinplate. Shredding of air-oxidized scrap or caustic leaching of scrap oxidized in solution reduced tin levels from the initial 0.25-pct level to about 0.1 pct.

Jan 1, 1973

By James P. Bennett

To improve construction materials for emerging chemical and metallurgical technologies, the Bureau of Mines is investigating the acid resistance of ceramic materials. In the study described here, eight commercial ceramic materials comprising two red shale, two fire clay, a silica, a silicon carbide, a carbon, and a high-alumina brick were evaluated. Samples were exposed to 20 wt-pct HC1 at 50° C for 110 days. The test apparatus designed to evaluate the materials is described. Changes in chemical and mineralogical composition, cold crushing strength, volume, and weight, and leach rates of AI, Ca, Fe, K, Mg, Na, Si, and Ti ions were monitored. In general, the statistically significant physical property changes that occurred were small. In many cases, no changes were detected.

Jan 1, 1982

By C. Stephan, E. Weiss, J. Trackemas, M. Sapko

The National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory (PRL), in collaboration with the Mine Safety and Health Administration (MSHA), the mining industry and seal manufacturers, conducted a series of full-scale experiments within the underground experimental mine at PRL's Lake Lynn Laboratory. The purpose of the experiments was to evaluate the explosion-resistant characteristics of several new seal designs for rapid deployment during mine emergencies. These seals can be deployed in less than 12 hours and are capable of withstanding explosion overpressures in excess of 140 kPa (20psi). These novel seal designs use available mine materials, do not require conventional rib hitching and, most importantly, can substantially reduce exposure time for coal miners during sealing and mine recovery operations.

By F. Garcia, J. Cervik

The cross-measure borehole technique has been shown by the Bureau of Mines to be an effective method of controlling methane liberated by fracturing the roof strata in longwall gobs where overburden is less than 750 ft (229 m). Boreholes are drilled into roof strata before mining operations affect the roof strata. Longwall mining fractures the roof strata and releases methane from source beds. Surface exhausters or vacuum pumps are used to draw the gas to the surface through an underground pipeline and vertical exhaust hole. The captured methane is thus prevented from entering the mine's ventilation system. About 71 pct of the methane produced by longwall mining in the Lower Kittanning Coalbed was captured by the cross-measure boreholes. Borehole spacing is an important factor affecting the performance of the technique. Interference tests and measurements of methane flows in return air indicate borehole spacing in the Lower Kittanning Coalbed should be limited to about 200 ft (61 m) except on the first 600 ft (183 m) of the longwall, where spacing should be reduced to about 100 ft (30 m) to capture the large quantities of methane released when the first large roof fall occurs. Comparisons between measured and calculated gas pressure differentials on boreholes indicate borehole length can be reduced from 280 to 140 ft (85 to 43 m), which reduces drilling costs significantly. Additional experimentation is necessary to verify the calculations.

Jan 1, 1985

By Maria I. De Rosa

The U.S. Bureau of Mines conducted a study to determine if correlations exist between the chlorine or nitrogen contents of materials and the hydrogen chloride (HCI) or hydrogen cyanide (HCN) concentrations evolved during the thermal decomposition of these materials. Hydrogen chloride, hydrogen cyanide, and carbon monoxide (CO) were found to be the primary toxic gases evolved during the combustion process. The experiments were carried out in a 20-L furnace with 1-g samples. The furnace temperature, rising from ambient, was set at 1,000 °C with an airflow of 10 L/min. The variables measured were the gas loads (milligrams per gram) of HCI, HCN, CO, and CO2 (carbon dioxide); CO and CO2 concentrations as a function of time were also measured. Other variables included the average concentrations of submicrometer smoke particles and particles' average diameter, mass of particulates, sample and furnace temperatures, and sample weight loss. The data indicate that there are significant correlations between the percentage of chlorine or nitrogen contained in the original samples and the HC1 or HCN concentrations evolved during the combustion of the materials. These correlations may be used to predict and evaluate a material's toxic hazard during combustion.

Jan 1, 2010

By G. W. Elger

The Bureau of Mines conducted laboratory and larger scale studies on samples of domestic perovskite and ilmenite ore concentrates to devise a procedure for recovering TiC from these ores. From the concentrates, mixtures of titanium and calcium carbides were produced. The carbides were then ground and reacted with water. This reaction decomposed the CaC2 to acetylene and hydrated lime and simultaneously liberated the TiC. Using a combination of elutriation and gravity-separation techniques to separate the hydrated lime, approximately 93 pct of the titanium was subsequently recovered as purified carbide containing 54 to 70 pct titanium with CaO content as low as 0,6 pct. This combination of techniques can be used to separate more than 90 pct of the CaO from the TiC. Therefore, this carbiding procedure is a viable method for treating titaniferous materials, including perovskite, that contain more than 20 pct CaO. Tests made in a static-bed reactor showed that for the reaction of TiC with elemental chlorine to produce titanium tetrachloride (TiCI4), a temperature of at least 940° F is desirable to achieve a suitable extraction of titanium in a laboratory chlorination reactor. In fluidized-bed tests at 840° F, 98 pct of the titanium contained in TiC was extracted.

Jan 1, 1980

By Thomas V. Falkie, R. Venkataramani

1. Summary This investigation is concerned with description of the loading function at the underground coal face, and the identification of varia¬bles - geological, geometric, mechanical, and operational - that affect the loading function. The immediate objective of this work was to provide information for operations-research studies as applied to underground coal mining, and the broad objective was to provide guide¬lines for planning and equipment selection in underground coal mining. The loading function was expressed as -a statistically-developed linear mathematical model. Originally, fifteen independent variables were considered which potentially could have influenced the loading function. These variables were constructed on the basis of measurable or estima¬ble geometric and geological properties at the working face, mechanical characteristics of the mining machine, and certain operational proce¬dures of mining. The original model explained 64.0 percent of the experimental variation. The final condensed model explained 54.1 percent of the experimental variation in terms of only five indepen¬dent variables, namely: 1. Ratio: width of cut/total width of cutter 2. Ratio: height of cut/diameter of cutter 3. Total horsepower of cutter-drive motors 4. Rotation speed (RPM) of cutter 5,. A subjective estimate of machine quality and operator skill Certain limitations were found to exist in the evaluation of the variables. Principle among these limitations was the impossibility of precise measurement of tonnage loaded in certain instances.

Jan 1, 1972

"In sum, significant benefits to mine worker health have resulted and should continue to result from the synergistic scientific, engineering, and medical research in respirable dust. As always, an important objective is the rapid dissemination of the results of this research to industry. Video tapes and the Technology News series published by the United States Bureau of Mines (USBM) have been a very effective means of technology transfer. Individual no-cost subscriptions to the Technological News series are available from the Bureau of Mines, Branch of Technology Transfer, 2401 E St., N.W. Washington, DC, 20241.Two respirable dust conferences have been jointly sponsored by the Center, USBM, NIOSH, and MSHA. The proceedings from these conferences are titled:1. Coal Mine Dust Conference held in Morgantown, West Virginia on October 8-10, 1984 and2. Respirable Dust in the Mineral Industries: Health Effects, Characterization and Control held in University Park, Pa. on October 14-16, 1986.Copies of the proceedings from the first conference are available from the National Technical Information Service (NTIS):National Technical Information Service5285 Port Royal RoadSpringfield, VA 22161NTIS # PB86-169380Telephone Number: (703)487-4650Copies of the second conference proceedings, ISBN: 0-936712-76-7 (publication #3010), are available from ACGIH by writing toWilliam D. KelleyExecutive Director, A.C.G.I.H.6500 Glenway Avenue, Building D-FCincinnati, Ohio 45211Telephone Number: (513)661-7881During the period 1984-1987 more than sixty-four (64) papers and publications have been produced by the Center researchers. These publications have appeared in scientific journals and have been presented at national and international symposiums and meetings. A list of these papers, organized by topical headings, has been included in this publication.The generic center maintains a reference center that serves as a clearinghouse for technical information for the generic area and supplies reports on generic center accomplishments."

Nov 1, 1988

By R. C. Buehl

Pilot-plant tests have been in progress at the Bureau of Mines, Pittsburgh, Pa., on the recovery of manganese from open-hearth slag.3/4/5/ In the process, 1 the slag is first reduced in a blast furnace to make a high-phosphorus spiegeleisen containing 12 to 22 percent manganese. A slag containing 55 to 60 percent manganese is made from this spiegel by oxidation in a basic-lined converter. The metal from this blowing operation contains about 3 percent phosphorus, 1 percent manganese, and less than 1 percent carbon. Economic efficiency in the manganese-recovery process requires that this metal be converted into steel. Because of its high phosphorus content the metal is suitable for blowing in a basic-lined converter. In most of the tests described in this report, metal of this composition was used as the starting material in a 1-ton, side-blown, basic-lined converter. Although basic-lined converters are not used for steel production in the United states, in Europe a considerable portion of the steel is made in them. Open hearths largely have replaced converters for steelmaking in the United States; mainly because open-hearth steels have better physical properties than converter steels because of lower nitrogen and phosphorus contents. However, by improving converter design and operating technique during the past 15 years, metallurgists have found that low-nitrogen steels with physical properties equal to open-hearth steels can be produced in converters.6/ Tests at Jones & Laughlin steel Corp. with side-blown, acid-lined converters of 3 and 22 tons capacity showed that steel with a low nitrogen content comparable to that of open hearths operating on scrap charges could be made by surface blowing.7/

Jan 1, 1955

By J. Douglas Causey

In 1986 and 1987, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied 73,010 acres of the 76,480-acre Lower Owyhee Canyon Wilderness Study Area (OR-003-110) in order to evaluate its identified mineral resources. The study area is in Malheur County, OR, about 8 miles north of Rome. There are approximately 7.7 million tons of subeconomic zeolite (heulandite and/or clinoptilolite) resources with ammonia ion exchange capacities as high as 1.75 milliequivalents per gram in the Chalk Basin-Lambert Rocks area. The bed is 25 ft thick with less than 100 feet of overburden. This resource probably will not be mined in the foreseeable future.

Jan 1, 1989

By T. E. Green, E. F. Spano, W. J. Campbell

A combined ion - exchange X- ray spectrographic method was developed and evaluated for determining trace amounts of cobalt and nickel in high - purity tungsten and tungsten trioxide . The sensitivity for both cobalt and nickel is in the range from 0.2 to 0.5 μg ( 0.04 to 0.1 ppm , based on 5 gram samples ) . Accuracy at the 5 to 20 μg level is ±10 percent of the amount present . Approximately 16 hours elapsed time is required for analysis

Jan 1, 1963

By D. J. Bauer

Solvent extraction techniques were used to determine the extraction sequence of yttrium and the rare-earth elements in an amine solvent extraction system. Single-stage extraction with Primene 81-R resulted in separation factors of 3.8 between yttrium and dysprosium and 25 between yttrium and cerium. Yttrium was concentrated in the aqueous phase. EDTA and DTPA, as aqueous phase counterextractants, enhance separation factors in mine-rare-earth sulfate systems. Yttrium separation from heavy rare-earth elements exhibits marked sensitivity to the position of yttrium in the selectivity scale of the rare-earth elements with the sequestrants. Yttrium-ytterbium separation is more effective with EDTA, whereas yttrium-dysprosium separation is more effectively increased with DTPA.

Jan 1, 1963

By Richard A. Thomas, Isaac A. Zlochower, Gregory M. Green, Kenneth L. Cashdollar, Martin Hertzberg

This paper reports the results of flammability studies for methane, propane. hydrogen, and deuterium gases in air conducted by the Pittsburgh Research Laboratory. Knowledge of the explosion hazards of these gases is important to the coal mining industry and to other industries that produce or use flammable gases. The experimental research was conducted in 20 L and 120 L closed explosion chambers under both quiescent and turbulent conditions, using both electric spark and pyrotechnic ignition sources. The data reported here generally confirm the data of previous investigators, but they are more comprehensive than those reported previously. The results illustrate the complications associated with buoyancy, turbulence, selective diffusion, and ignitor strength versus chamber size. Although the lower flammable limits (LFLs) are well defined for methane (CH,) and Propane (CA), the LFLs for hydrogen (HZ) and its heavier isotope deuterium (D2) are much more dependent on the limit criterion chosen. A similar behavior is observed for the upper flammable limit of propane. The data presented include lower and upper flammable limits, maximum pressures, and maximum rates of pressure rise. The rates of pressure rise, even when normalized by the cube root of the chamber volume (V 1/3), are shown to be sensitive to chamber size.

By R. V. Ramani, V. T. Burgos, J. A. McClay

This report was prepared by The Pennsylvania State University under USBM Contract No. G0111808. The contract was initiated under the Coal Mine Health and Safety Program. It was administered under the technical direction of DMSE, with Mr. G. R. Schottler acting as the technical project officer. Mr. J. A. Herlckes was the contract administrator for the Bureau of Mines. This report is a summary of the work recently completed as part of this contract during the period June, 1971 to September, 1974. Thls report was submitted by the authors on February 13, 1975.

Jan 1, 1975

By M. R. Geer

The widespread adoption during the past decade of the dense-medium process for cleaning coal increases the need for technologic studies of the process. Such studies provide information that will insure maximum usefulness of this process in its present form and may well lead to substantial improvements in design and opera¬tion. The Bureau of Mines has published the results of cleaning trials on a wide variety of coals in two dense-medium pilot plants5/ and reported the recovery of coal from waste by dense-medium treatment.6./ The present report deals with the viscosity of magnetite dense medium, an important subject about which virtually nothing has been published. Specifically, the report concerns methods for measuring viscosity, the influence of various medium contaminants on viscosity, the effect of viscosity on cleaning results, and the influence of viscosity on consumption of medium. Cleaning trials on four coals of varied density composition in a pilot plant, using mediums of different viscosities, showed a steady reduction in cleaning efficiency with increasing viscosity in every instance. However, the behavior of each coal in a viscous medium was distinctly individual. With one, an increase of only 1 centipoise in viscosity caused a reduction in recovery efficiency of 7.7 percent, whereas the same increase in viscosity with another reduced recovery efficiency only 2.7 percent.

Jan 1, 1957

By David R. Hanson

Transient electrical noise events pose serious problems for data acquisition systems used in monitoring acoustic emissions in laboratory and field environments. The U.S. Bureau of Mines has designed and constructed a trigger discriminator circuit for use in ultrasonic acoustic emission studies. Designed for use with signals in the frequency range of 50 to 400 kHz, the instrument examines .incoming signals for frequency content, amplitude, simultaneity, threshold crossings, and number of channels above threshold. If preselected criteria on these properties are met, a plus 5-V pulse is output that may be used to trigger a data acquisition system, allowing rejection of noise events that do not possess useful information. The system was designed for four input channels, but may be expanded to more channels with minimal design changes.

Jan 1, 1995

By M. Hayashi

The Bureau of Mines conducted laboratory studies on low-grade vanadiferous silicates from the Pumpkin Buttes and Nine Mile Lake deposits of Wyoming to examine techniques for extracting vanadium and uranium. Recovery from low-grade sources such as these could contribute to future vanadium production and reduce reliance on vanadium imports. The Pumpkin Buttes samples contained 0.03 to 0.04 pct V205 and 0.06 to 0.12 pct U308; the Nine Mile Lake samples contained 0.02 to 1.0 pct V205 and 0.06 to 0.19 pct U308" Leaching the Pumpkin Buttes samples for 18 h at 800 C with addition of 200 lb/ton H2S04 resulted in recoverey of 80 pct of the vanadium contained in the samples. The Nine Mile Lake samples were readily leached, yielding 78 to 94 pct of the vanadium after 3 h at 800 C with addition of 100 lb/ton H2S04, A solvent extraction procedure was used to selectively recover urani-um from Pumpkin Buttes and Nine Mile Lake leach solutions and to recover vanadium from the raffinates. In batch shakeout tests, Alamine 336 recovered over 95 pct of the uranium from leach solution adjusted to pH 1. Di-2-ethylhexyl phosphoric acid and Cyanex 272 recovered vanadium from the uranium raffinate after reduction and adjustment to pH 2; vanadium extractions of up to 96 pet and 92 pct, respectively, were achieved.

Jan 1, 1985

By E. J. Ostrowski, P. L. Woolf, J. P. Morris, Norwood B. Melcher

By injecting natural gas through auxiliary tuyeres into the smelting zone of the Bureau of Mines ' experimental blast furnace in January 1959 , the investigators succeeded in reducing the coke consumption by approximately one - third that of the base period . This caused a 30 - percent increase in pig iron production with no increase in wind rate . The maximum gas addition in these experiments was 4,665 cubic feet per ton of metal produced . Sharp reduction in gas consumption occurred when high hot blast and high wind rates were used , although the gas injection rate in percent of air blown remained constant . As the heat energy produced by burning natural gas to carbon monoxide and hydrogen is much less than burning coke to carbon monoxide , greater blast temperatures were required during the test runs . The gases produced from the methane were , however , more effective reductants ; so it was possible to increase the production rate while reducing the total heat requirements per ton of metal produced . During a base period with an all - sinter burden , before introduction of natural gas , a coke rate of 1,484 pounds per net ton of pig iron was attained , using an average blast temperature of 1,518 ° F. Gas was introduced gradually over a two -week period until an average 7 percent of the air blown was reached . During this period , the wind rate was adjusted downward to maintain a constant flow of gas in the bosh . The production rate of the furnace remained relatively constant . The quality of pig iron, however , improved as the sulfur load on the furnace was reduced as a result of the substitution of gas for coke . Blast temperatures were increased during this period from 1,518 ° F. to 1,939 ° F. , when the maximum gas addition was reached .

Jul 1, 1960

By D. S. DeLong, A. Giza, D. G. Fraser, V. A. Robinson, T. B. Whitmoyer, J. E. Sneckenberger

"A cotton dust animal exposure system has been modified to incorporate a microcomputer feedback loop to monitor particle concentrations. The loop's major components are a minature real-time aerosol monitor (miniram) to estimate concentrations and a microcomputer to read the miniram's data and to control a stepper motor that adjusts the amount of dilutant air mixing with respirable cotton dust. Ninety minute trials of this system indicate that the standard deviation of particle concentrations is within 0.68 Mg/m3 of the average concentration, insuring a near constant concentration of respirable dust throughout the exposure.INTRODUCTION Previous workWeyel et al. (1984) have determined that respirable cotton dust can be shaken from bulk cotton samples using acoustical energy. The particle generator designed to utilize this fact operates like a commercially available sonic sifter, but on a much larger scale.While this generator successfully resuspended trapped respirable cotton dust, the generator output concentration decreased exponentially with time. This disadvantage was solved by Frazer et al. (1986) by operating the generator with a sinusoidal voltage near the minimum resonance frequency of the generator. This adjustment enabled the generator to produce respirable cotton dust for six hours or longer.Frazer et al. (1987) utilized the modified acoustical generator to produce a cotton dust animal exposure system. The cotton dust concentrations were estimated by a miniram, a light scattering aerosol Monitor. The system operator used the miniram values to adjust the system's parameters to maintain the desired concentration level.PurposeThe objective of this study was to introduce a computerized feedback loop to the operator controlled cotton dust animal exposure system. The miniram's estimates were analyzed by a microcomputer to determine what adjustments in the flow of dilutant air were necessary to maintain the desired cotton dust concentration. These modifications were intended to improve system performance and ease the system operator's work burden."

Jan 1, 1988

By P. L. Woolf, J. P. Morris, E. Foerster, G. R. Zellars

Measurements of vapor pressure can be used to determine the thermodynamic activities of the components of metallic solutions . The determination of activity by this method requires accurate values for the vapor pressure of the pure component and for its partial pressure above the alloy solution . This investigation was conducted to measure the vapor pressure of liquid manganese for use in future studies of the activity of manganese in various liquid alloys . In related investigations in the Bureau's Pyrometallurgy Laboratory , vapor pressures of copper , iron and nickel have been measured and activit 4 5 6 have been determined in the iron- copper and iron- nickel systems . Difficulties were experienced with manganese which were not encountered in the previous investigations . Manganese oxidizes readily and greater care was needed to maintain an oxygen- and moisture - free atmosphere in the furnace . In addition , liquid manganese wet the refractories and there was a tendency to foam and splash on introduction of the carrier gas . Because of these difficulties several variations in the experimental procedure were studied . These were first tested with silver which has a vapor pressure of the same order of magnitude as manganese but is relatively inert at high temperatures . Although no significant changes in the original procedure resulted from this work, considerable data were obtained for silver and have been included in this report . Bauer and BBrruunnnneerr7/ have reported the only extensive investigation of the vapor pressure of liquid manganese . However , their results are not consistent with the data obtained by McCabe and Hudson for solid manganese . Measurements of the vapor pressure of silver have been reported by McCabe and Birchenal1,2/ Schadel and Birchenall , 10/ Harteck , 11 / Fischer , 12/ and von Wartenberg.13 / Generally , these investigators conducted their measurements at lower temperatures than were used in this study .

Jul 1, 1960