Search Documents

By S. P. Kinney

During 1925, at Holt, Ala., the United States Bureau of Mines made a study of the composition of the gases at four elevations in the shaft of a furnace producing foundry iron. A report3 of the work was published in 1927. Some of the results of this investigation are shown in Figure 1. As indicated, the gas at the center of the shaft is low in CO2 content, while the gas in the vicinity of the wall is higher in CO2. The composition of the gases at the top and at the center of the stock column was not far different from the composition of the gas at the top of the bosh. The investigation indicated clearly that lean gas was channeling through the center of the column. More recently the study was enlarged in scope to include investigation of a furnace operating on Lake Superior ores in the Chicago district. A series of planes between the stock line and tuyères was surveyed. Means and apparatus were developed for obtaining, between the inwall and the center of the furnace, the gas composition, gas velocity, and temperature on each plane. A complete report4 of the investigation has recently been published.

Jan 1, 1929

By James W. Miller

An investigation was begun by the Bureau of Mines in 1948 to determine the preparation characteristics of American coals. Results of the investigation were planned to be reported on a county basis and from the data developed, to determine: (a) Which coals either as mined or after beneficiation by conventional preparation are chemically suitable under present standards for producing metallurgical coke; (b) Which coals require special and more intensive treatment in preparation than is now practiced; and (c) Which coals cannot be considered potential sources of metallurgical coke, regardless of preparation. This report is one in this county series that describes the preparation characteristics of the coals of Perry County, Ky.

Jan 1, 1956

During the period 1979 thru 1982. Multi Mineral Corporation conducted a mining research program at the United StAtes Department of the Interior's Bureau vi Mines Oil Shale Mining Environmental Research Facility in the Central Piceance Creek Basin, Rio Blanco County, Colorado. The program consisted of mining, environmental and geotechnical research data and. the results are described in this report.

Jan 1, 1983

By Khamis Y. Haramy

This U.S. Bureau of Mines report describes the use of Bureau-developed flat and cylindrical hydraulic borehole pressure cells. A brief description of the fabrication, installation, and pressurizing equipment is given and pressurizing procedures are discussed. Theories available on evaluation of data from the flat and cylindrical pressure cells and examples of data analysis and stress evaluation are also presented.

Jan 1, 1991

By R. S. Dean, John Gross

"In a preliminary report made a year ago it was shown that certain minerals when subjected to heating with water under high pressure and temperature were shattered upon the sudden release of that pressure. The main feature in which the results of this method differ from those of conventional grinding is in the differential effect obtained. The more metallic minerals, and hence the valuable minerals, are shattered more readily than are the gangue minerals. In other words, explosive shattering is unique among possible methods for comminuting an ore in that it wastes the least energy on the useless part of the ore. Explosive shattering, therefore, offers possibilities as a means for reducing grinding costs, arid it is this potential advantage of the process that makes it worthy of further experimental study. The first part of this paper is devoted to a study of the mechanism of the process; the, second part reports results obtained in toots on a selected list of ores to exhibit some of the advantages of explosive shattering."

Feb 1, 1933

By C. E. Wood

Because of the renewed importance of the strategic metal manganese the Bureau of Mines in conducting further research on pyrometallurgical methods of beneficiating manganiferous iron ores and low-grade manganese ores. Published data on the Pyrometallurgical of manganese ores have been reviewed by Joseph.5/ A method of treatment that has received less consideration than others is the matte smelting of manganese or the separation of manganese from the iron and the gangue in an ore b, formation of a matte, that consists principally of esulfide of manganese. A procedure of this type has been patented by Betts.6/ Lofquist7/ claims advantages for the production of a sulfide-oxide matte as a method of recovering manganese in alloys containing manganese and iron.

Jan 1, 1940

By Potts J. D.

Installation of a horizontal air-blocking shelf around the inside perimeter of the surface mining drill deck shroud is proposed to improve dust capture. Without the use of this shelf, a strong Coand? effect airflow pattern results in dust leakage to the environment, especially at the shroud-to-ground interface. Bailing air exits the drill hole and travels along the drill steel to the underside of the table, where it fans out across the bottom of the drill table and continues down the sides of the shroud. This dust-laden bailing air then strikes the ground and fans out under gaps between the shroud and the ground. The proposed shelf prevents dust-laden air from striking the ground by redirecting it toward the center of the enclosure, where it can be captured. Laboratory tests demonstrated that the shelf reduced dust levels outside of the shroud by 81% under operating conditions consisting of a 1.9:1 collector-to-bailing-airflow ratio and a 51-mm (2-in.) gap between the shroud and ground. The shelf was 152-mm (6-in.) wide and was located at a height equal to 2/3 the distance measured from the bottom of the shroud to the bottom of the drill table. The air-blocking shelf was also capable of overcoming the adverse impact of vertical leakage along the shroud seams as long as this leakage was confined to an area below the horizontal plane defined by the shelf location.

Jan 1, 2008

By J. D. Davis

"Introduction.Sixty years ago, M. Berthelot found that ethylene could be selectively absorbed from gaseous mixtures by concentrated sulphuric acid, and that the compound formed by the chemical union of the gas and acid was readily decomposed by heating with water, yielding ethyl alcohol. Only within the last few years has there been any attempt to make use of this discovery technically.Bury*, working in England at the Skinningrove Iron Works and on a commercial scale, developed a technical method for converting, the ethylene of coke-oven as into alcohol. With a gas containing less than 3 per cent of ethylene, he obtained a yield of 1.6 gallons of alcohol per ton of coal carbonized.De Loisy** perfected a technical method for treatment of coke-oven as for alcohol. Evidently this work was carried out on a semi-commercial scale. His method is based on the use of catalytic agents for hastening the absorption of ethylene by sulphuric acid. He uses part of the spent acid for drying the gases and pact for the manufacture of ammonium sulphate. Excess acid is reconcentrated by waste heat. Others have worked on the problem, but so far there has been no large recovery of ethylene from coke-oven gases. The chief difficulty seems to lie in the low efficiency (about 50% of methods and tae relatively low concentrations of ethylene in the gases treated. Gas from Trent amalgam*** contains much larger percantages of ethylene than does coke-oven gas, as Will presently be shown, and if it should ever prove practIcal to treat industrial ;as for alcohol, this gas would offer attractive possibilities,* Bury, Ernest, Ethylene as Alcohol from Coke-Oven Gas: Gas Journal' Vol. 148, D. 30, 1919, pp. 718.** DC Loisy, M.E., Sur un procede' industrial de fabrication syntlotique de l'alcool et de l'ether a partir des gaz de distillation de la houil Comp Rend, vol. 170, Jan. 1920, p. 50-3.*** A paste consisting of approximately part oil such as that obtained as for cleaning coal. See Perrott. in cleaning coal, Chem 3 parts finely pulvarized coal and 1 final product in the Trent, process StJ, and Kinney, S.P. The use of oil Vol. 35 August 3, 1921, p, 183.. & Met."

Nov 1, 1922

[ ]

Jan 1, 1981

By James J. Dawd

The investigation to evaluate the reserves of coking coal is being made by the Bureau of Mines in three parts: (1) To estimate known measured and indicated recoverable reserves of all coking coal; (2) to upgrade marginal coals through effective preparation; and (3) to study carbonizing properties of coals and coal blends not now widely used for metallurgical coke making. This is the ninth of a series of reports giving results of studies by counties under part (1) of the investigation. (See Appendix.) This report covers Raleigh County, W. Va., which comprises parts of Bald Knob, Eccles, Beckley, Meadow Creek, Mullens, Flattop, and Big Bend quadrangles. (See fig. 1.) A base map for each bed in each quadrangle was made to the scale 1 inch equals 1,200 feet. Maps of mines, location of drill holes, bed and total coal thickness, and outcrop of the bed were plotted on the maps. With all available data plotted, isopach lines were drawn to limit areas of known unmined reserves in beds 0 to 14 inches thick, 14 to 28 inches thick, 28 to 42 inches thick, and over 42 inches thick. These areas of coal reserves also were divided into measured" and "indicated" categories. All areas in each thickness range and in each category, mined-out areas. areas excluded from the estimate but which may contain reserves based only on geologic inference, and areas outside of the outcrop were measured by planimeter on the base maps, Estimates of total reserves 14 inches and more thick and maps for individual beds were prepared from these data.

Jan 1, 1952

By J. C. Edwards

The National Institute for Occupational Safety and Health (NIOSH) implemented a real-time neural network system which can discriminate mine fires from nuisance diesel emissions as part of an atmospheric mine monitoring system in NIOSH?s Safety Research Coal Mine. The real-time response of a neural network to fire sensor outputs was demonstrated for coal and belt combustion in the presence of diesel emissions. The fire sensors consisted of an optical path smoke sensor, a carbon monoxide (CO) sensor, and two types of metal oxide semiconductor (MOS) sensors. The real time neural network was trained with coal, wood, and belt fire experiments with and without diesel emissions background. The trained neural network successfully predicted mine fires with these combustibles in the smoldering stage prior to the onset of flames.

Jan 1, 2005

By Paul E. Bennett, James S. Browning, Thomas L. McVay

Continuous 1.0- to 1.5 - ton - per - hour pilot plant flotation tests were made to determine the technical and economic feasibility of recovering beryl from flotation tailing being produced at the spodumene concentrator of the Foote Mineral Company , Kings Mountain , N.C. Best results were obtained when using an acid circuit and amine - type cationic reagents to float a bulk beryl - feldspar concentrate and then selectively floating the beryl away from the feldspar , using a petroleum sulfonate collector . About 77 percent of the beryllium in the pilot plant feed was recovered in a concentrate containing 6.42 percent BeO . The capital cost of an integrated flotation plant capable of treating 500 dry tons of spodumene mill tailing per day for recovery of beryl and feldspar is estimated at $ 210,000 . Indicated direct operating costs for the plant were $ 1.52 per ton of dry spodumene flotation tailing treated . This approximated the value of beryl recovered , but potential profits of about the same magnitude lie in concurrent recovery of marketable spodumene and feldspar byproducts .

Jan 1, 1964

By Slavoljub D. Maksimovic

At some coal mines, methane gas is released during raise drilling. At the request of the Mine Safety and Health Administration (MSHA), U.S. Department of Labor, the Bureau of Mines conducted ventilation surveys at different raise drill sites to assess various methods of reducing methane concentration. The resulting data indicate that raise drill shaft cavities are ventilated by air compressors, vacuum pumps, auxiliary blower fans, and free intake air from the surface. The compressors, pumps, and fans operate simultaneously or separately. At the bottom of the shaft cavities, ventilation is controlled by regulators and airlocks. Methane is monitored, measured, and periodically sampled on the surface, at the bottom, and at different levels in the shaft cavities. Maximum concentration of 3.5 percent was measured in one shaft in West Virginia. Air velocity down the raise drill shafts is always very low, Maximum recorded air down the drill stem was 3,000 cfm, which can be increased by adding air compressors. The best way to ventilate shaft cavities is through the simultaneous use of air compressors and vacuum pumps. If the methane concentration cannot be reduced with additional compressors, then the inside diameter of the drill rod should be increased, or larger pilot hole drill bits should be used.

Jan 1, 1981

By Joe B. Rosenbaum

New applications and concepts of solvent extraction as a unit operation in extractive metallurgy have been developed in the last decade. Wider use is being made of established solvent extraction techniques in processing spent nuclear fuel elements and in winning columbium-tantalum, hafnium-zirconium, thorium, tungsten, uranium, and vanadium. Commercial application has been extended to recovery of beryllium, boron, bromine, copper, molybdenum, phosphorus, rare-earth metals, and rhenium. Systems in use and proposed typically extract metals or salts as anion, cation, or neutral species from aqueous media by reaction with a recycleable organic reagent.

Jan 1, 1971

By Frank G. Horino

The Bureau of Mines studied the uniaxial compressive strength of model rock pillars as a function of the angle and spacing of noncohesive planes of weakness. The model pillars were prepared from NX 2-l/8-inch diameter drill core of limestone, sandstone, and granite, and the planes of weakness were diamond saw cuts ground flat and smooth. The angle of the planes of weakness, measured from the horizontal, varied from zero to 57° in approximately 15° increments. When two planes of weakness were used, the thickness-to-diameter ratio of the wafer was 1/4, 1/2, and 1, Approximately 400 model pillars were tested in uniaxial compression. The results indicate that the uniaxial compressive strength of model pillars decreases rapidly as the angle of the plane of weakness increases from 30° to 57°, and that the spacing of these planes of weakness has only a minor effect on the strength. The effect of the number of horizontal planes of weakness, with a spacing of 1/4 and 1/2 of the diameter, upon the compressive strength of model pillars was also investigated. These results indicate that as the number of planes of weakness increases the compressive strength of the pillar decreases. Normalizing the data provides useful estimates of model pillar strengths for any rock type.

Jan 1, 1968

By Lon D. Santis

The Code of Federal Regulations Title 30, Parts 56, 57, 75, and 77 require that detonators and explosives be separated by four inches of hardwood or equivalents when transported together in mines. This standard was developed to protect the explosives from initiation by the more sensitive detonators. The research reported here is an attempt to quantify the fire protection offered by four inches of red oak and other materials. Boxes with a volume of 6.75 cubic feet were made from four-inch thick rough green oak (RGO), two-inch thick RGO plied, two-inch thick #1 common (dried) red oak plied, and a metal/plywood composite. These and boxes meeting the Institute of Makers of Explosives' (IME) Safety Library Publication No. 22 were tested in bonfires. The boxes were instrumented with thermocouples, filled with detonators, and placed over a kerosene fire imparting about 16 kilowatts per square meter heat flux for up to 3 hours. Tests showed that the wood boxes protected the detonators for over an hour with variations between the different trials. In the IME 22 container tests, detonators began exploding in as little as 17 minutes in one test and not for 2-/12 hours in another test. Detonators in the metal/plywood boxes began to explode in about 15 minutes but with minor alterations, were able to contain the detonators. The test results show that the exterior of an IME 22 container significantly affects its thermal properties. Defects in the form of cracks and the manner in which the container is closed have a significant effect on the performance of a detonator container in a fire.

By L. C. IlsLey

The Burrell methane indicator developed by Col. G. A. Burrell in 1915 was modified during 1918 to the " insulated type " Burrell indicator . Though this instrument has been used in mines since its first introduction , it was not formally approved as safe and efficient for use in gaseous mines until March , 1922. The indicator is built by the Mine Safety Appliances Co. , Pittsburgh , Pa . Approval No. 800 has been assigned to this company covering the device in the form approved . The principle of the Burrell indicator is fairly well known . It works on the same principle as the Haldane apparatus - measuring by means of a graduated scale , the contraction resulting from burning the methane content of an air and gas sample . A given aniount of the mine atmosphere to be tested for methane is taken into the indicator . This sample is then thoroughly shaken with the water in the indicator for one minute . The methane in the sample is now burned for two minutes by a heated platinum coil , which is energized by a small storage battery containing two Edison cells connected in series . After the glower or coil has burned for two minutes , it is disconnected from the battery , and the indicator is again shaken for The amount of contraction observed by reading the height the water rises in the U- tube of the indicator , which is calibrated to register the percentage of gas in the sample . The indicator as approved by the Bureau of Mines is equipped with an Edison M- 8 mine- lamp battery , and with a glass and scale graduated from zerɔ tɔ four per cent methane . The approval of a corbination service that is , an attachment for giving illumination from the same battery from which the platinum glower is operated has been withheld pending the development of a battery with larger capacity . - Under laboratory operating conditions , a single glower was capable of making at least 20 determinations if proper precautions were observed with respect to the use of freshly charged batteries . A battery should be allowed to stand off charge several hours before using in an indicator , as the peak voltage of a freshly charged Edison cell is abnormally high and is likely to send enough current through the glower to melt the platinum wire . Fifty-seven satisfactory operations were obtained from a completely charged battery . The point where the voltage of the cell fell below 2.3 volts with the glower attached was taken as the lower limit of successful operation . A voltage less than 2.3 does not permit the lower to burn at a temperature that will completely burn the gas in the air , thus giving a false indication .

Jun 1, 1922

By C. R. Summers, J. N. Murphy

In response to the Coal Mine Health and Safety Act of 1969, mandatory noise standards have been developed that specify time-noise limits of mine personnel exposure. Most affected by elevated noise levels is the pneumatic roof bolter operator, both in terms of levels near or in excess of 115 dbA and in terms of length of exposure. Therefore, the principal emphasis of this Bureau of Mines report is on pneumatic drill noise control. It is not the intent of this report to suggest any drill redesign; instead, methods are suggested to reduce the noise level by complementing existing machines. An integral muffler system and a separate muffler system were tested in an attempt to lower pneurnaric drill noise levels. Pneumatic drills, when new, operate at about 115 dbA when drilling in sandstone. Using the drill muffler systems, it was possible to decrease the noise level of a 115 -dbA s rope drill to approximately 100 dbA.

Jan 1, 1974

By Thomas M. Barczak

This U.S. Bureau of Mines report describes methods to enhance the capacity, stiffness, and timber utilization of wood crib supports. Since stiffer supports minimize strata deflections that contribute to roof instability, efforts to maximize crib stiffness while maintaining stability through a wide displacement range should be a design priority. The stiffness and capacity of conventional crib designs, employing alternating layers of wood timbers that are loaded perpendicular to the grain, can be increased by increasing the interlayer contact area or by using higher strength wood. Contact area can be increased by using wider timbers or employing more timbers per layer. Concepts that provide parallel-to-the-grain timber loading will provide substantial increases in crib stiffness and capacity. Two concepts that utilize this principle are examined: (1) an original South African design that constructs wood cribs from preformed layers (mats) of timber where short blocks are oriented vertically between horizontal slabs; and (2) a design that employs full lengths of timber placed vertically in the interior of a conventional crib structure. These designs also provide more efficient timber utilization by providing greater support capacity per volume of wood used in the crib construction.

Jan 1, 2010

By H. S. Caldwell

Molten zinc, condensed from zinc vapor, was used by the Federal Bureau of Mines to leach aluminum from an aluminum-silicon alloy made by carbothermic reduction of silicious aluminum ores. Zinc requirements were minimized by re-fluxing condensed zinc in a low-pressure, Soxhlet-type distillation unit. The minimum ratio of zinc used to aluminum in the crude alloy was approximately 2:1. When the system pressure was reduced from atmospheric pressure to 100 microns or less, the rate of aluminum extraction increased by a factor of 20. Leaching rates were much higher when the zinc vapor was condensed directly on the crude alloy than when molten zinc was passed over the alloy in the absence of appreciable zinc vapors. Observations indicated higher extraction efficiencies from crude alloys containing greater amounts of iron. Complete extraction was obtained with negligible loss of zinc. Assuming complete removal of zinc, the aluminum products will contain 1 to 6 percent silicon and about 0.5 percent iron plus titanium. The leached crude-alloy residue is a highly friable spongelike material containing about 80 percent silicon, several percent iron and titanium, with the remainder aluminum. This extraction method has been patented (Patent 2,810,637) and assigned to the Government. Research and development investigations are continuing at the College Park Metallurgy Research Center.

Jan 1, 1961