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By Dean C. Holt

This work was done to appraise the potential of titanium minerals in known titanium- bearing placer deposits and potential titanium- bearing placer areas in western Montana . Reconnaissance studies were made of more than 225 stream areas . Churn drilling and other placer exploration techniques were used in sampling eight deposits . The sampling results indicate that areas containing more than 10 pounds of ilmenite and other titanium- bearing black - sand minerals per cubic yard occur in the Bitterroot , Upper Clark Fork , and Jefferson River drainages . The chief source for the constituents of the black sands appears to be the Idaho batholith , and the highest black - sand concentrations are generally found near the source . Sample testing methods include gravity and magnetic separation and visual microscopic as well as chemical and radiometric analyses on deposits sampled in detail .

Jan 1, 1964

By Nicholas Kyriazi, John P. Shubilla

A joint effort by the U.S. Bureau of Mines (USBM) and the US. Mine Safety and Health Administration (MSHA) was undertaken to determine how well self-contained self-rescuers (SCSR's), deployed in accordance with Federal regulations (30 CFR 75.1714), held up in the underground environment with regard to both physical damage and aging. This report presents findings regarding laboratory-tested SCSR's in the fourth phase of testing from 1989 to 1993. The SCSRYs were tested on human subjects and on a breathing and metabolic simulator (BMS). These results indicate that most of the apparatus, if they pass their inspection criteria, perform as expected except units with manufacturing defects. However, when the apparatus are carried in and out of the mine daily and stored at the working section, they may suffer abuse. Physical signs of abuse, unless extremely obvious, are frequently not detected by the miners or mine operators. In addition, some apparatus collected for this study had not been returned to the manufacturer in a recall effort for correction of a manufacturing defect. In both cases, the apparatus would have presented problems in emergency use. Recommendations include improved training in inspection procedures and better enforcement of recall notices.

Jan 1, 1994

By E. K. Stanek

This report contains results of two major efforts related to electrical transients on mine electrical power systems. The first area concerns the use of digital computers to model mine electrical power systems and predict transients or duplicate field recordings of transients. Two existing general purpose circuit analysis programs were used. The first was the TRW Engineering System Simulator or TESS. The second was Electronic Circuit Analysis Program or ECAP. TESS proved to be superior to ECAP in several important characteristics, including system size limitations and modeling nonlinear elements. The second major topic covered in this report is the evaluation of commercially available surge suppression devices. These devices were found to be quite acceptable and guidelines for the selection and placement of surge suppressors were included. The final important item is a listing of the worst-case transients, from a design point of view, for ac and de utilization systems and ac distribution systems.

Jan 1, 1979

By Denise A. Herzog

The U.S. Bureau of Mines conducted a study of cyanide leach technology used in Alaska's mineral industry from 1987 through 1990. Literature and cost data were obtained for mines in the contiguous United States, Canada, and Alaska that use cyanide to recover gold and silver. The data was compiled in an effort to evaluate the economics and conditions associated with cyanide use in Alaska. This report discusses heap leaching methodology and evaluates a "typical" heap leach operation in Nevada and compares the results of the Nevada operation to an analogous hypothetical mine in Interior Alaska. Five daily tonnage rates were analyzed for both the Nevada and the Alaska operations to evaluate the spectrum of economic possibilities. The discounted cash flow rate of return (DCFROR) for each production rate was then evaluated in terms of recoverable metal value (RMV). The Nevada RMV for each production rate was then compared with its Alaskan counterpart, and the results averaged. The Alaskan production costs are an average of 1.71 times greater than costs associated with mining in Nevada at a 0% DCFROR. At 15% DCFROR, costs in Alaska are 2.01 times greater than those in Nevada. Costs are higher in Alaska because of the shorter leaching season, increased labor and transportation costs, and heavier precipitation and vegetation.

Jan 1, 1991

By W. D. Ludemann, E. A. Loria, E. A. Rowe

The isothermal recrystallization of electrorefined vanadium has been studied as a function of annealing time , temperature , and prior deformation . Specimens were cold- rolled from 30- to 75 - percent reduction in thickness , then annealed from 700 ° to 1,200 ° C at time periods ranging from 1 minute to 96 hours . The course of recrystallization was followed by means of hardness , metallographic , and X- ray techniques , and a recrystallization diagram was constructed . Interpretation of the data indicated that there was around 50- percent softening due to recovery ( first stage of softening) before recrystallization began . The defining of recrystallization limits with respect to the amount of deformation was precisely established for electrorefined vanadium . More than 30- percent reduction was necessary for recrystallization to occur at 850 ° C. With 60- percent reduction , it was initiated at 750 ° C and completed at 950° C. The activation energy for recrystallization , as derived from the data , was 95,300 cal per mole for 60 - percent reduction and annealing at 750 ° to 900 ° C. Recrystallization by the mechanism of nucleation and growth was the principal process during the second stage of softening . minor part of the second stage of softening took place as strain- induced boundary migration , which was observed in specimens reduced 30 percent , bent in L- shape , and annealed at 950 ° C. Grain size decreased significantly only with the largest reductions and annealing between 750 ° and 950 ° C. Grain growth was expressed by the empirical relation D = KKtt"" ,, the exponent being the same at 60- percent reduction and annealing from 750 ° to 900 ° C. Accordingly , the activation energy for grain growth was 75,000 cal per mole .

Jan 1, 1964

By W. J. Fullerton

This paper is one of a series being prepared by the U. S. Bureau of Mines describing mining and milling methods and costs at cement-plant quarries throughout the United States, end deals directly with methods and costs at the quarry and mill of the North American Cement Corporation at Catskill, N. Y. The process of manufacturing cement is described only as far as the final grinding of the raw materials. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent local operating expenditures only and not total production costs. It is recognized that publication of total production costs may in many instances cause embarrassment to individual producers, as well as to the industry as a Whole. On the other hand, operating costs are essential to the technical discussion and study of methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding; of the scone of the cost tabulations may ensue.

Jan 1, 1931

By David Schlain

The galvanic corrosion properties of titanium and zirconium were investigated by the Bureau of Mines. The dissimilar metals involved in these experiments included magnesium, magnesium alloy FS1, aluminum alloys, zinc, steel, tin, lead, copper, Monel, nickel, and several stainless steels. Couples were immersed in synthetic ocean water, tap water, 5-percent ammonium sulfate solution, 5-1/2-percent sodium chloride solution, sodium hydroxide solution, 0.1 N hydrochloric acid, and various concentrations of sulfuric acid.

Jan 1, 1956

By M. C. Irani

This Bureau of Mines survey of methane emissions indicates that total daily emissions have declined from 227 MM ft3 in 1971 to 214.7 MM ft3 in 1973. The highest average daily emissions in million cubic feet per day observed in U.S. bituminous coal mines were, in decreasing order, Monongalia County, W. Va., 40.7; Marion County, W. Va., 23.1; Buchanan County, Va., 22.1; Washington County, Pa. , 12.4; Greene County, Pa. , 11.7; McDowell County, W. Va. , 11.4; Cambria County, Pa., 9.8; Jefferson County, Ala., 9.5; Wyoming County, W. Va., 6.0; Marshall County, W. Va., 4.8; and Indiana County, Pa., 4.8.

Jan 1, 1974

By Albert W. Deurbrouck

This report describes the preparation characteristics of the Pittsburgh and Upper Freeport coalbeds in Hancock , Brooke , Ohio , and Marshall Counties , W. Va . Over 4.5 million tons of coal was produced in these four counties in 1962. Most of this production came from the Pittsburgh coalbed . Twelve coal samples were collected for this study , 11 from the Pittsburgh bed and 1 from the Lower Freeport bed . Two of these samples could be upgraded to produce metallurgical - grade coal . The sulfur content of the Pittsburgh- bed coals was generally excessive --as high as 4.9 percent in the raw coal and 3.19 percent in the float 1.30 specific gravity fraction . The rank of the coals in this area ranges from high-volatile A to high-volatile B bituminous .

Jan 1, 1964

By G. W. Birge

Fifteen coal samples, representing the Winifrede, Chilton, Alma, No. 2 Gas, Powellton, Eagle, Douglas, Sewell, Beckley, Pocahontas No.4, and Pocahontas No.3 beds in Wyoming County, and five samples, representing the Fire Creek, Pocahontas No.6, and Pocahontas No.3 beds in Mercer County, W. Va., were carbonized at 9000 C by the Bureau of Mines-American Gas Association (BM-AGA) method, and yields of products and physical properties of cokes were determined. Expansion characteristics of the majority of samples were determined in the Bureau of Mines sole-heated oven. Chemical analyses and agglutinating values were determined for all coals. The coals were mostly strongly coking and low in ash and sulfur content. Dry, mineral-matter-free fixed-carbon content of the Wyoming County coals ranged from 63.0 to 83.4 percent. The Mercer County samples were all low volatile in rank. Yields of carbonization products were generally in accord with yields from similar rank coals of the Appalachian region. Because of their expanding tendencies, most of the medium-and low-volatile coals would require blending with lower rank coal for normal coke production.

Jan 1, 1965

By Clarence O. Babcock

This report describes the results of Bureau of Mines laboratory and preliminary field tests on a rock bolt of helical shape. The flexible construction allows the bolt to maintain a more stable load level than is possible with a straight bolt. Bolt load changes resulting from anchor slippage, blasting shock, or changes in mine geometry with mining advance are minimized. Preliminary field tests were performed at the Kaiser Steel York Canyon mine where the load changes of straight and helical bolts were measured using a vibrating-wire load gage. The field tests were performed to establish the viability of the concept of a helical bolt. The practical usefulness in terms of performance and economics remains to be shown. The change in bolt load for the flexible bolts was one-third that for the straight bolts. There were no malfunctions of the gage, and the bolts maintained a more uniform load than the straight bolts used as controls.

Jan 1, 1978

By Larry G. Stolarczyk

This report deals with the creation of an efficient method to determine if command, control, communication and monitoring (3cm) equipment in coal, metal and non-metal mines is susceptible to Radio Frequency Interference (RFI) from the Medium Frequency (MF) radio communications system. A qualitative and quantitative RFI test plan was developed for in-mine and laboratory evaluation of the equipment. The laboratory testing was accomplished using the TEM Test Chamber. Detailed information on the Test Plan and the TEM Test Chamber is included. During in-mine testing of the MF System some underground equipment malfunctioned when the transmitter's radiating antenna was in close proximity. Electromagnetic Compatibility (EMC) testing was done on three levels; Component (circuit or box), subsystems and system. Nine tables are included which show the results of testing various equipment for RFI.

Jan 1, 1986

By D. A. Paice

A power supply to operate fluorescent or mercury vapor lamps from 300 volt dc coal mine trolley wires has been developed for the Bureau of Mines. A high frequency regulated inverter unit incorporates ballasts for a mix of lamp loads up to 650 watts. For 600 volt trolley systems an additional power converter unit was developed to step down the dc voltage to 300 volts for the inverter unit. Both units have operated in a working coal mine for over 12 months without need for servicing. The lamp load in these tests included two 100 watt mercury vapor head lamps and six 75 watt fluorescent lamps.

Jan 1, 1979

By Thomas J. Peters

The Danskin/South Fork Boise River study area is 40 air km southeast of Boise, Idaho. The 16,000-hectare, two-segment area is mainly underlain by Cretaceous-age granodiorite and an aplitic and pegmatitic complex of the Idaho batholith, Miocene-age rhyolitic tuffs and lavas, and late Tertiary-age basalt flows. No mineral resources were identified in the study area. One mine, The Flat Creek mine, which produced several ounces of gold and silver, was found in the study area. It is geologically similar to deposits in the Neal mining district, adjacent to the northwest corner of the area; gold mineralization occurs along east-northeast-trending faults and associated quartz veins, which dip moderately to steeply southeast, and within adjacent Cretaceous granitic rock. Samples indicate the Flat Creek deposit is not rich enough to mine underground, and near surface, open-pit-mineable deposit areas could not be identified. However, exploration is warranted there and also in the 7-km interval to mines in the Neal district, and for extensions of those mines. No evidence of geothermal activity was observed, although there are hot springs in the vicinity. Some alluvial (placer) samples from the interior of the study area contained free gold, but no substantial gravel deposits were seen.

Jan 1, 1993

By Robert W. Freedman, Robert L. Craft, William G. Humphrey

As part of a continuing effort to reduce the weight and bulk of equipment that mining personnel must carry underground, the Bureau of Mines and the Mining Enforcement and Safety Administration (MESA) investigated accurate and convenient gas samplers for use by mine inspectors in sampling mine atmospheres. The samplers are septum-stoppered glass vials commonly used for routine blood sampling. These lightweight, compact samplers yield results comparable with those obtained with conventional bottle samplers of 250-ml nominal capacity.

Jan 1, 1975

By D. E. Wolfson

This report presents 900° C BM-AGA carbonization and related data for coals from the principal beds of Nicholas, Randolph, and Webster Counties, W. Va. Thirty-three samples from nine coal beds in three counties were car-bonized at 900° C in the l8-inch-diameter BM-AGA retort, data from which have been correlated with industrial production. Host of the samples were chemically suitable for metallurgical use, and their coking properties were satisfactory. Except for four of the Lower Kit-tanning samples, the ranges of constituents in the coal seams were 1.8 to 9.0 percent ash and 0.4 to 1.1 percent sulfur, values within the range of accept-ability for metallurgical coals. Coke strength indexes were normal for Appalachian coals of similar rank, and the tumbler stability indexes of the coke ranged from 35 to 57.

Jan 1, 1969

By Carl R. Peterson

This report describes the development and testing of a prototype tunneling machine. Principal efforts were aimed at testing of the fragmentation subsystem of a continuous drill and blast hard rock excavation machine suitable for use in underground mining and tunneling applications. The concept utilizes a unique self -shielding spiral blasting pattern that permits efficient performance with relatively small single shots, while at the same time directing major blast fragments at right angles to the tunnel axis. A major accomplishement was the development of a remote controlled, loading and initiation system in which explosive slurry and a detonator are Simultaneously placed (pumped) into the blasthole via a loading hose. The special electric long-delay detonator is inductively ignited upon emplacement, and the machine remains at the face during the blast.

Jan 1, 1976

By Ned Baker

This report describes the development, construction and testing of a hydrogen-fueled underground mining vehicle. A hydrogen burning engine and a hydride fuel system, both previously developed, were installed on a modified utility vehicle, together with the necessary controls. In tests and in actual use, the vehicle performance in terms of speed, acceleration, and gradeability exceeded that of the standard, unmodified vehicle.

Jan 1, 1985

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 D. B. Taliaferro

Information regarding the pores or voids in reservoir rocks is vitally important in the scientific extraction of petroleum from natural underground reservoirs, and petroleum technologists concerned, with subsurface, conditions have devised various methods that give reasonably accurate information as to the porosities of oil and gas-bearing sands.5/ In this, work, several investigators have made use of the experience of the ceramic and other industries. The method of determining the effective porosity of oil sands described in this report falls within the general classification of gas-expansion methods. It was devised and developed at the United States Bureau of Mines Petroleum Experiment Station, Bartlesville, Okla., as a part of the research dealing with fluid and energy relations in reservoirs and improved oil-recovery methods. The apparatus and procedure are well adapted to the requirements of the Bureau, and the following detailed description has been prepared so that others may make use of the information. A tabulation at the end of the report gives the results of several hundred porosity determinations for oil sands in fields of 11 States.

Jan 1, 1937