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By W. J. Huff, G. W. Jones, I. Spolan, R. E. Kennedy

"INTRODUCTION Information on the exploeibility and ease of ignition of acetylene is important in connection with investigations by the Bureau of Mines and others seeking the causes of explosions in medium-pressure acetylene generators.A previous report 6/ gave preliminary results of an investigation made by this Bureau to determine the causes of these explosions. This report indicated the need of amending Federal specifications for ""1/4 by 1/12"" carbide to reduce the amount of fine sizes permitted under the specifications then in force. Tests described in the above report showed that certain sizes of carbide may, under certain conditions, attain excessively high temperatures when acetylene-water vapor mixtures are passed through carbides for extended periods.Federal specifications P-0-101, Amendment 5, June 28, 1944, are now in effect. These latest specifications permit a maximum of 7 percent of ""1/4 by 1/12"" carbide by weight to pass through a 0.0661-inch sieve and a maximum of 2 percent to pass through a 0.0555-inch sieve. Experience has shown that these specifications have insured a safer size range of carbide for medium-pressure acetylene generators.Although the improvement in the size range of the carbides has aided in the prevention of explosions, there have been explosions in which the carbide used at the time of the explosion met the latest Federal specifications."

Sep 1, 1945

By T. J. Batchler, T. M. Barczak

The Code of Federal Regulations (CFR) requires that the transverse load capacity of stoppings be equal to or greater than traditionally accepted in mine controls, which for block stoppings is generally accepted as 39 psf as referenced in the preamble to the CFR standard. This measure is based on physical testing of a freestanding wall in accordance with ASTM E 72 specifications, where our past research has shown that the dominant parameter is the tensile strength of the sealant. A new protocol based on rigid arch loading of the structure is proposed to determine the true transverse load capacity of block stoppings. Arching is achieved by the restraint of the stopping against the mine roof and floor, whereby compressive forces are developed within the wall. A laboratory procedure using the NIOSH Mine Roof Simulator (MRS) to simulate rigid arching of block stoppings was developed and results verified through full-scale in-mine tests. The rigid arch tests have demonstrated transverse load capacities more than an order of magnitude higher than the ASTM E 72 evaluation method from which the 39-psf requirement is derived. More importantly, the rigid arch tests have shown that the load capability is dependent on the physical properties of the block and geometric properties of the wall and not the sealant.

By C. H. Riggs, Kenneth H. Johnston

The application of modern secondary-recovery methods has made possible the the extraction of more than 13 million barrels of crude petroleum from the eastern part of the Delaware-Childers field Nowata County, Okla., over and above the production that might have :been expected by continuing primary production methods, including the use of vacuum. Foremost among the secondary-recovery methods used in this foil was the repressuring of the Bartlesville sand with air and gas through injection wells spaced on sym-metrical patterns. Between 1925 and 1945, about 51 billion cubic feet of air and gas were injected into the producing formation, and the total recovery was increased from, 25 million to about 40 million barrels of oil. To produce as much as possible of the 28 million barrels of recoverable oil remaining in the sand will require the initiation of systematic water-flooding projects on many properties and the continuation of air and gas injection on others.

Dec 1, 1946

By Z. T. Bieniawski, Benjamín Celada

After emphasizing the importance of quantitative rock mass classifications in mining, originally directed to selection of rock support measures, but subsequently to estimates of rock mass properties such as rock mass strength and rock mass modulus of deformation, current attention calls for a classification specifically for rock mass excavability by tunnel boring machines (TBMs), which are used extensively in tunneling as well as in the mining industry. This paper introduces the Rock Mass Excavability (RME) index for predicting excavability of rock masses by TBMs using a quantification of machine performance and rock mass conditions. The RME index is based on five input parameters aimed at relating rock mass behavior and machine characteristics: (1) uniaxial compressive strength of the rock material, (2) drillability/abrasivity, (3) rock mass jointing at mine drift face, (4) standup time of the excavation, and (5) groundwater inflow. Development of the RME index entailed the collection of extensive data from more than 28 km of tunnels and some 400 case records from projects in Spain involving double-shield TBMs. In the process, a number of statistical correlations have been established between RME and such output parameters as degree of machine utilization, advance and penetration rates, thrust and torque of the cutterhead, and the specific energy of excavation. It was found that the RME index provides a particularly significant correlation for predicting the average rate of advance (m/day). In essence, the RME index is a classification system that features interaction of rock mass conditions with boring machine characteristics for use in the early stages of a project. It should be noted that the RME index does not replace the Rock Mass Rating (RMR) or Q-systems as used in mining and tunneling; indeed, one of the RME input parameters, standup time, is determined from the RMR. However, the approach presented introduces a specialized tool relevant to excavating tunnels and drifts. Possible applications to hard-rock mining are explored.

Jan 5, 2007

By P. Yant, R. R. Sayers, R. D. Lieitch

"PURPOSE OF INVESTIGATIONOf more than 300 bituminous mines examined by Crichton 5 and his assistants in connection with litigation in Indian Creek Valley, Payette County, Pa., only four were found to have alkaline water. That work and many observations from of the authors have shown the general prevalence or acid drainage from bituminous coal mines. In connection with investigations pertinent to coal-mine drainage that are being conducted by the United States Bureau of Mines, it was noted with considerable interest therefore, that a mine in the Thick Freeport bed about 20 miles north of Pittsburgh had no acid water in the workings, As it was thought that this condition might be common to all mines,this condition in this bed most of them were visited, samples of the outflow and from different parts of the mine inside were examined, and such general information as was available was gathered.ACKNOWLEDGMENTSThe authors acknowledge with thanks the courteous assistance of mine officials in connection with collecting the data for this paper, and of the analytical and coal laboratories of the Bureau of Mines for analyses."

Nov 1, 1932

By Andrew M. Leszcykowski

In 1984, personnel from the U.S. Bureau of Mines examined 41,550 acres of the North Fork Owyhee River Wilderness Study Area for mineral resources. This study area, in southwestern Idaho, is underlain by tuffs and basalt of Tertiary age. There are no known mines, claims, or prospects in or near the area. The northeast and southwest corners of the area are covered by oil and gas leases or lease applications, but no known exploration has been conducted. On Nickel Creek and Pleasant Valley Tables, in the southern part of the area, thin flows of vesicular, moss-covered basalt occur that are suitable for use as decorative building stone. The stone available for exploitation crops out over several square miles. However, more suitable material, outside the study area, is closer to potential markets.

Jan 1, 1986

By E. P. Carman

1. CARMAN, EVERETT P., OPPERMAN, MARTHA, NISHIYANA, SALLY, AND RACOOSIN, LEE. Bibliography of Bureau of Mines Investigations of Coal and Its Products, 1945 to 1950. B. 528, 1954, 60 pp. 40 cents. 2. ROSE, HAROLD J. Industry-Sponsored Coal Research in the United States. Chap. in Proceedings: Fifth International Conference of Directors of Mine Safety Research. B. 489, 1950, pp. 9-12. $1.25. Minerals Yearbook 3. STRINER, HERBERT E., CARMAN, E. P., AND GOODING, RICHARD M. Review of the Mineral-Fuel Industries in 1952. Minerals Yearbook 1952, Fuels, vol. 2 (pub. 1954), pp. 1-28.

Jan 1, 1958

By George S. Rice

"""To prevent the propagation of mine explosions, the Bureau of Mines, Department of Commerce, recommends rock-dusting all coal mines, except anthracite mines, in every part, whether in damp or dry condition. It also recom¬mends that rock-dust barriers be used to sectionalize the mine as additional defense; but these should not be regarded as a substitute for generalized rock-dusting."" (Mine safety decision, No. 5, April 7, 1927.)The purposes of this circular are to present concisely the requirements for effective rock-dusting of coal mines in order to prevent propagation of mine explosions, and to point out the principal related facts on explosibility of coal dusts and mixed coal-mine dusts, as determined by extensive testing in the Experimental Mine of the Bureau of Mines. study of these principal facts on coal-dust explosibility in conjunction with the recommendations for rock-dusting, should help to make clear to mine operators and others concerned the necessity for systematic rock-dusting in all coal mines except anthracite mines, and the futility of inadequate or sporadic rock dusting.The descriptions of nearly 1000 explosion tests in the Experimental Mine are available in a forth-coming bulletin2 and in earlier publications.3For detailed specifications as to the kind of rock-dust, amount to use, where to be applied, and method of sampling and testing, the reader is referred to Bureau of Mines Serial 26064, and American Engineering Standard Committee ""Recommended American Practice for Rock-Dusting Coal Mines"" quoted in Bureau of Mines Information Circular No. 60305.Summary of Specifications for Rock-Dusting1. Mines to be rock-dustedAll coal mines, except anthracite mines, should be rock-dusted.2. Extent of rock-dustingAll open accessible parts of a coal mine should be rock-dusted, including slopes, entries, cross,-cuts, and rooms, headings and pillar workings to within at least 50 feet of the face.3 Amount of rock-dustingAfter cleaning up the coal dust as thoroughly as practicable, sufficient rock-dust should be used to have the mixture of remaining coal-dust plus the rock-dust in any zone contain 65 per cent or more of inert or noncombustible matter. First dusting may require 3 pounds to 5 pounds per linear foot of passageway.4. When to rock-dust In any zone or section (made by dividing the mine for rock-dusting purposes) when the incombustible content falls to 55 per cent, that section should be re-rock-dusted so as to bring the incombustible content well above 65 per cent."

Jun 1, 1927

By Frank D. McGuirk

Underground coal mining is traditionally hazardous. Although many danger-prone human activities are now performed by mechanized equipment, this mechanization has itself brought new dangers to the underground mining industry, and the loss of life and limb has caused increased concern for mine safety. The 1969 Federal Coal Mine Health and Safety Act has precipitated a great deal of safety-related research on the part of the Government, industry, and private agencies. Much of this safety research has been focused on the new and varied man-machine interfaces caused by increased mechanization. Recent projects in this area have dealt with standardized controls, emergency shutdown capabilities (panic bars, strike plates, self-centering controls, "dead man" controls), and machine operator protective devices (fully enclosed cabs, canopies, side rails). There was a need for integration of the findings of current and past projects to move rapidly toward the smooth, orderly implementation of standardized operator work station designs for underground mining equipment.

Jan 1, 1975

Determine the advantages and operational limitations of water-let-assisted cutting used with mining equipment. Approach The Bureau of Mines con-ducted a research study to evaluate water-Jet-assisted cutting both in the laboratory and in underground mines. Earlier research on water-jet-assist was limited to laboratory studies where bit speeds and penetration depths were very low and large cutting force reductions were reported. For the past years, research by the Bureau of Mines and others has been concerned with the application of water-jet-assisted cutting under more realistic mining conditions. Study Results Water-jet-assisted cutting employs a mechanical cut-ting bit combined with a moderate to high-pressure water jet directed just in front of the bit tip to assist in the cutting process. Recent Bureau findings show that the addition of the water jet to the cutting bit can improve cutting in harder materials, significantly reduce respirable dust and bit wear, and increase product size. Some of these findings are presented as follows.

Jan 1, 1987

By W. A. Calhoun

"INTRODUCTION A letter from S. D. Strauss, vice president of Metals Reserve Company, Washington, D.C., dated May 22, 1945, to the chief of the Metallurgical Branch, Bureau of Mines, in Washington; includes the following: Because of the present critical shortage that exists in the supply of corundum required by certain industries in war production, the Reconstruction Finance Corporation, Mr. W. C. Keeley, Vice Chairman for Metals and Minerals, War Production Board, has recommended that the Reconstruction Finance Corporation though Metals Reserve Company, proceed with preliminary mill testing of the corundum ore in Gallatin County, Montana, and that the results of that testing be transmitted to the War Production Board. If the results of the testing work are considered satisfactory, Metals Reserve Company will then provide for the actual mining and milling of the ore for the production of corundum concentrates.Pursuant to the above stated recommendation by the War Production Board, Metals Reserve Company desires to make -use of the facilities of the Bureau of Mines testing plant at Rolla, Missouri, for conducting sink and float and other concentration tests on representative samples of the Montana corundum ore. Two, and possibly three samples of ore are to be tested which will have an aggregate weight of approximately 50 tons."

Dec 1, 1947

By Thomas J. Peters

In 1979 and 1980, the U.S. Bureau of Mines and U.S. Geological Survey conducted a mineral survey of the 15,600 acre (6,310 ha) Freel Peak RARE II area (No. 5271) in the Lake Tahoe Management Unit. This study by the Bureau of Mines indicates that potential for economic mineral resources in the area is slight. The only mineralized structures in the area consists of two quartz veins. One quartz vein, at the Mountain Top Mine (fig. 1), located by Fred Denner in 1932, is estimated to contain 2,000 tons (1,800 t) of silver and copper-bearing resources. Chip samples from the vein averaged 0.61 oz silver per ton (20.91 g/t), and 1.59 percent copper. The narrow vein is not economically mineable. The other quartz vein is poorly exposed and contains traces of molybdenum. A second reported molybdenum occurrence could not be substantiated.

Jan 1, 1982

By J. R. Thoenen

Occurrences of titanium, zircon, and other heavy minerals are widespread in Florida. Deposits concentrated as "heavy sands" by wave and wind action have been mined an or near Atlantic coastal beaches since 1916. An important inland concentration at Trail Ridge; .believed, to have formed along an ancient share line, was disclosed by preliminary investigations (1947) by the Bureau of Mines. This report describes investigations to determine the extent and grade of "heavy-sand" concentrations in other inland stabilized dune areas in the central and northeastern parts of the peninsular region of the State (fig. 1). Portions of the central highlands south of Trail Ridge and terraces and dunes in the coastal lowlands region, east and northeast of the ridge were investigated. Holes were drilled in 10 areas (see table 1 and fig. 2) along State and County roads and on private property. They were spaced 250 to 2,000 feet. apart to obtain a cross-sectional picture of "heavy-sand" content in the dune areas. These sections were generally placed in east-west directions normal to the general trend Of the peninsula to intercept one or more of the ancient shore lines in the various areas (figs. 3 to 13, incl.). A total of 433 drive piped and 333 jet holes were drilled, and 7,293 bulk and core samples were taken. Intermediate holes were placed at closer intervals when field analysis indicated 1 percent or more of heavy minerals present. All of the holes drilled and the analysis of samples that contain 1 percent or more of heavy minerals are listed in table 2. Profiles (figs. 14 to 20, inclusive) show the more favorable concentrations, which are irregular in outline and erratic in mineral content. The highest concentrations averaged 1.0 to more than 2.0 percent heavy-mineral content, but a few individual hole samples exceeded 3.0 percent in grade.

Jan 1, 1949

By D. K. Denton, J. M. Girard, D. F. Scott, T. J. Williams

Personnel from the Spokane Research Laboratory, National Institute for Occupational Safety and Health, examined an underground pillar at the Homestake Mine, Lead, SD. Investigations involved strain relief and seismic tomography studies in the mine, and ultrasonic velocity measurements on pillar core in the laboratory. Measured octahedral normal stress was 37 MPa (5,366 psi); seismic P-wave velocities averaged 5.2 km/s (17,060 ft/s); and ultrasonic velocities at a pressure of 39.6 MPa (5,750 psi) averaged 6.3 km/s (20,669 ft/s). The difference between in-mine and laboratory velocities is attributed to the attenuation of seismic energy by mine fractures larger and more numerous than those in the samples of core measured in the laboratory. Using these results, researchers hypothesize that pillar rocks have the ability to withstand stress an order of magnitude greater than they currently sustain.

By E. E. Harton

Bureau of Mines Information Circular 16, Bibliography of Investment and Operating Costs for Chemical and Petroleum Plants, was published in October 1949 as an aid in making estimates of investment and operating costs of processes for manufacturing synthetic liquid fuels. Development of such processes by the Bureau of Mines was authorized by Public Law 290, 78th Congress. This bibliography included refer¬ences to and abstracts of publications appearing from 1930 to September 1948 on all processes in general use in the petroleum refining and chemical industries. Publications in this field have been numerous since compilation of the above bibliography, and the present report was prepared to cover the field from September 1948 through June 1952.3/

Jan 1, 1955

By Charles H. Simmons

Two versions of a VF transceiver to aid in location of trapped miners has been developed and tested. The belt worn model was produced in both transmitter and transceiver configurations. In addition, a quantity of the belt worn models were fabricated using aluminum wire instead of copper in order to reduce unit weight. Ten prototypes of a battery cap model VF transceiver were also fabricated demonstrating further unit size and weight reduction while maintaining electrical performance. Samples of- both versions were tested environmentally and the test data is included in this report. While both versions of the VF transceiver are similar electrically, and are constructed using convential manufacturing techniques, the battery cap model realizes a lower total weight, smaller volume and production cost than the belt worn version. Operationally, the battery cap model assures that the VF transceiver will always be with the miner.

Jan 1, 1981

By Elaine T. Cullen

Miners, like many skilled blue-collar workers, are not traditional learners. They have not always been successful in classroom-type settings, preferring to learn on the job in a hands-on environment. U.S. law requires that miners have a minimum of 8 hours of safety training annually, plus 40 hours for underground miners and 24 hours for surface miners when they enter the industry. However, miners rarely view this training time positively. In fact, it has been called “safety jail” by many, who regard it as a time to get a little extra sleep While mining has become far safer in the past 100 years, it is still a dangerous occupation. The Office for Mine Safety and Health Research, a part of the National Institute for Occupational Safety and Health (NIOSH), has funded a project for the past 4 years to address this challenge. The purpose of the research was to find a way to develop effective safety training for these people. Miners are born story tellers. They share “near miss” stories, stories about master miners they have known, and stories about how things used to be. These stories not only pass along information about what will happen if a miner fails to respect the mining environment, they also instruct listeners in the culture of mining and the values that it embraces. Stories, it seems, are a way to get safety messages across to miners, especially inexperienced ones, and using older, wiser miners in these stories is an obvious choice. This paper will discuss how a series of training videos was developed, how “master miners” and story lines were chosen, and how the resulting videos have been received in the mining industry.

By Douglas F. Scott

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied an 11,980-acre part of the 33,300-acre High Rock Canyon Wilderness Study Area, CA-020-913B, in order to evaluate its identified mineral resources. No mineral resources were identified during this study, and no significant amounts of gold, silver, mercury, gem-grade opal, or placer gold are present. The study area is located in Washoe County, NV, about 53 miles southeast of Cedarville, CA. No mining districts or mineral production are known, and no oil and gas leases are in the area. No current claims are in the area; however, six placer claims were located in 1911 in High Rock Canyon near its confluence with Mahogany Creek.

Jan 1, 1987

By F. J. Wiebel

"INTRODUCTION As a result of a general survey of the iron-ore deposits of Califor¬nia, the Bessemer was one shown to offer possibilities of developing com¬mercial ore reserves. Surveying and exploring were done at the request of Congress for an investigation of raw materials for the production of steel.A wartime steel plant has been established at Fontana, San Bernardino County, and a backlog of iron-ore reserve for the maintenance of permanent steel industry on the West Coast will be of National benefit in the postwar period.W. D. McMillan, a mining engineer the Bureau of Mines, examined the property in May 1942, and it was reexamined by D. W. Butner, also of the Bureau, in October 1943. Geophysical work was done by the Bureau in 1944, and the property was explored by diamond drilling from April to August 1944 and February to SeptemberACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contri¬bution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, under the direction of Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, under the direction of R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests."

May 1, 1947

By E. R. Maize

[he scconG rcport of :his st?rI.org 8cdt with o3servatioi:s of conver- gence of roof an4 floor at t!x*re: ?.cc.-.tioris iri til~ ClVucible mine of kke Cru- cib1.o Fuel Co. Data on sl:'ociacnce ?.rd Lztcrcl mwe:~cnt cf the surface were .:lven for two of these areas, a-12 it was mentioned that ~lr~~ilar data were being obtained on a ?art of Pe:sc:rlvtzr.ia Fii~l?trr.y FE:, ~i!lic;l pcser: over the third area. 'I'hie hichw~ :LEO FasseE over t!lc ITenncoli::. :.line of the Bnckeye Coal Co. 9 milcs to ';he so-lth, cnd at P. l~tcr C'..att: ~.nr?r.,cc?r:cntS *.rere mnd.e to make similar observati on3 there. This y: pr mrnmri:.c n Czto obtnino? at those two locetionn,]

Jan 1, 1941