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By Michael F. Dunn

Since crushing of rock to a smaller size is an integral part of almost any mining and quarrying operation, a study was carried out to identify and develop improved techniques for alleviating a major cause of accidents and work stoppages arising when an oversize luck or boulder lodges in the throat of the crusher. The configurations and operations of various crusher types is described, sources of boulders in the mining operation, and a detailed review is made of mining, quarrying, and construction regulations for all states, Canada, and the Federal Government for applicable provisions. Representative mines were visited and other operations contacted for their boulder handling techniques where it was found that blasting techniques used included mudcapping, bombs, and blockholing, often done very crudely and inefficiently with poor practices and various mechanical systems were used such is hooks of, overhead cranes, impact hammers, and grapplers. Safety analyses of all methods pointed out the hazards associated with blasting in the open and the dangers of entering a crusher. Boulder blasting can be done in a safer fashion if a planned step-by-step procedure is followed, and inherently safer blasting products such as exploding bridge wire blasting caps and improved blockholing techniques. In general, though, the installation of a suitable mechanical system such as an impact breaker will prove safer and cost effective even in a smaller mine or quarry.

Jan 1, 1981

By Janine Pierce, Robert Larson, Christine Raasch

The vibration and impact environment for crew members on locomotives has been investigated in a series of studies conducted by Exponent Failure Analysis Associates (Exponent) beginning in 1990. Locomotive cab vibration and impact levels were measured on a variety of locomotive models operating over many different track sections across the Union Pacific, Burlington Northern Santa Fe, CSX, Norfolk Southern, and CONRAIL systems. The comfort and health implications of exposure to the measured locomotive vibration levels were evaluated by comparison with the human vibration exposure boundaries given in the International Standards Organization (ISO) standard 2631-1:1997, the British Standard 6841:1987, European Union (EU) Directive 2002/44/EC, measurements made by Exponent on various commercial and recreational vehicles, and vibration exposure measurement data found in the literature. Methods Initially, vibration levels experienced by locomotive crews were measured and recorded at incremental speeds covering the range of normal train operation. In 2003, a method of measuring the vibration exposure continuously by means of a digital recorder was developed, allowing the vibration level over the entire run or crew shift to be analyzed. For each seating location measured, acceleration was recorded on the seat surface beneath the ischial tuberosities (pelvis) of the seated crew member and on the cab floor directly under the seat. At each of the locations, triaxial accelerometers were used to measure the vibration along the longitudinal, lateral, and vertical axes. Since the vibration environment varies throughout the route, and locomotive vibration levels have been found to be primarily speed dependent, a speed sensor was used to continuously measure the speed of the train. To evaluate the recorded vibrations levels, the data was divided into two-minute segments, which were each processed per the 1997 ISO standard for weighted RMS vibration levels and Vibration Dose Values (VDV). Additionally, PSDs and 1/3 Octave RMS values were calculated to determine the frequency content of the vibration. For each two-minute segment, the average speed of the locomotive was calculated to allow for correlation with the recorded vibration exposure values. The resulting exposure values for the entire run were calculated by combining the data from all of the two-minute segments. Since introducing the continuous method of recording acceleration, 23 seating locations have been recorded on 11 locomotives traveling 11 different routes across various parts of the United States. One of the routes was a shift of ‘yard work’, traveling back and forth in a rail yard coupling train cars together. Results A guide to interpreting weighted acceleration values with respect to health is given in Annex B of the 1997 ISO standard. A health guidance caution zone is defined to indicate the

Jan 6, 2006

The coal-bearing strata of Oklahoma occur in the eastern part of the state over an area of 14,500 square miles, 20.7 percent of the state's total area. Commercially valuable deposits of bituminous coal cover about 8,000 square miles in seams ranging from ten inches to five feet thick. Estimated reserves in Oklahoma are 1.6 billion tons, representing 0.3 percent of U.S. coal reserves. The vast majority of coal mined in Oklahoma used in a single power plant within the state. Oklahoma gained primacy when its regulatory program was conditionally approved January 19, 1981. Authority for the state to administer the Abandoned Mine Land program was granted January21,1982. On April 30,1984, the Office of Surface Mining substituted direct federal enforcement of the inspection and enforcement portions of the Oklahoma program. This substituted enforcement was based upon a finding by OSM that Oklahoma had not operated the inspection and enforcement portions of its program effectively. As of January 1, 1986, Oklahoma inspection and enforcement authority was reinstated. Full program authority was granted to Oklahoma on January 14, 1986.

Jan 1, 1992

By J. F. McIlwain

Cobalt-base hardfacing alloys used for wear resistance consist almost entirely of metals largely imported into the United States. As part of an overall research program to help alleviate this foreign dependency, the Bureau of Mines has been investigating an iron-base alloy system as a potential replacement for cobalt-base alloys for some uses. To ascertain the melting ranges, thermal analyses were made of cast heats of alloys containing, in weight percent, 59-61 Fe, 16-19 Cr, 8-9 Ni, 1 Mn, 1 W, 1 Mo, 0.5 Cb, 0.6 Si, 0.3 C, and 0-12 stoichiometric TiB2. Powder alloys within this range of composition, prepared by mechanical alloying, were sized and applied to mild steel test coupons by nontrans-ferred-arc plasma spraying. The resulting thin coatings were >95 pet dense, with bond strengths of 35 MPa and hardness of 400 to 840 DPH. Abrasive and adhesive wear test data were compared to those of a plasma-sprayed cobalt-base alloy. A range of boride contents resulting in most promising properties was determined for further research.

Jan 1, 1985

By Stephen W. Lambert

The Bureau of Mines examined the wellbore of a vertical gas drainage well in the Mary Lee coalbed to determine the results of specific completion procedures in coal. A jet-slotting tool was used to cut four vertical slots through the casing about 1 ft below the coalbed. Even though stimulation treatment pressure was excessive, hydraulically induced channels were contained entirely within the target coal zone. Sand-filled, induced channels were horizontal, inclined, and vertical, and were propagated in directions similar to bedding planes, rock joint, and coal cleat directions measured in the mine. Variable gas flow rates, recorded during the productive life of the well, were attributed to chronic downhole pump malfunction and the slotted casing below the production zone.

Jan 1, 1978

By T. M. Barczak

The term "resultant load vector" is defined as the representation of the forces applied to a longwall roof support element by strata activity through a single, quantifiable measure of support resistance. The relatively complex kinematics of the shield structure prohibits determination of support resistance simply from the summation of leg forces. In the research reported in this Bureau of Mines study, the mechanics of the shield structure were evaluated, and a technique was developed whereby the resultant shield loading could be determined by instrumenting supports with pressure transducers and strain gauges to measure leg, canopy capsule, and lemniscate link forces. This technique has been laboratory tested in the Bureau's Mine Roof Simulator. Functional relationships among variables were assessed, and confidence intervals were established for prediction of the resultant load vector parameters. Resultant load measurements were taken on five instrumented shields on an active longwall face in Colorado. Results were analyzed and found to be consistent with shield mechanics and anticipated roof behavior. Benefits to be derived from this research, future efforts, and long-range goals are discussed.

Jan 1, 1986

Coal mining in Indiana is limited to the south-western portion of the state, with coal currently being recovered in 19 counties. The coal-producing area of the state covers approximately 6,500 square miles. Although most of the coal in Indiana is recovered by surface mining methods, a small percentage is recovered through underground mining. To date, 40 percent of the known coal reserves have been removed. Indiana has about 33 billion tons of identified coal reserves, of which approximately 17 billion tons are recoverable using current technology. Of this recoverable coal, about 15 billion tons are recoverable by underground mining and 2 billion tons are recoverable by surface mining methods. The State of Indiana has regulated the environmental impacts of coal mining since 1941. Indiana was the second state in the nation to pass legislation requiring mined land reclamation. Its SMCRA regulatory program was approved July 29,1982, and its Abandoned Mine Land Program was approved July 29, 1982.

Jan 1, 1992

By Ann G. Kim

The U.S. Bureau of Mines applied its mine fire diagnostic method to an abandoned anthracite mine fire site in Carbondale, Lackawanna County, P A. The technique to locate fires in abandoned coal mines and coal refuse piles includes the determination of hydrocarbon concentrations in mine gases, the imposition of an underground gas flow direction, and use of a surface mapping method, to define heated and cold zones in underground coal strata. The heated zones at Carbondale were characterized by elevated methane concentrations. The results of 25 communication tests were analyzed to define 2 large (approximately 100 by 250 ft) and 5 small, isolated heated zones. An approximate correlation existed between the location of the heated zones and areas of anomalous snow melt. The correlation between the results of the diagnostic? test and subsurface temperatures was not significant.

Jan 1, 2010

By William P. Harris

The Lincoln Terminal System is described as a device with the capability to deliver technical information, monitor student performance, and assure learning in industrial training. An experimental unit, the LTS-3S, was constructed and delivered to the Bureau of Mines with appropriate lesson material for a test of feasibility and acceptability of this form of training in the mining environment. Operations were conducted at two mine maintenance schools. The overall results were that (1) there was a substantial improvement between tests before and after self-training on the LTS, (2) students found this an acceptable way to learn, and (3) reaction by training personnel and supervisors was favorable toward the feasibility and advantages of using the LTS in the mining environment. Transfer of the LTS to industry depends on availability of reliable units and adequate lesson material. The requirements for authors of training materials were established based on advice from mine training experts, formal analysis of lesson development procedures, and experience from efforts in lesson development at Lincoln Laboratory-It was concluded that experienced mine training instructors were best qualified to proceed effectively and economically to format instructional material for the LTS, if supported by well-designed facilities and services. Discussion with mining experts confirmed the desirability of generating training materials and delivering instruction at distributed locations to meet local training needs and in direct support of industrial operations.

Jan 1, 1975

By J. A. Herdlick

Under authority of the Strategic Materials Act of June 1939, the Federal Bureau of Mines, in cooperation with the Geological Survey, began a broad program of investigation of the strategically important chromite deposits in Sweetgrass, Stillwater, and Carbon Counties, Mont. Extensive occurrences of chromite along the Stillwater Complex in Stillwater County were investigated. The two principal deposits, The Mouat-Sampson and Benbow mines, ultimately were developed and placed in production by the Federal Government. As a part of this general development program, the Carbon County chromite deposits near Red Lodge were examined by Bureau of Mines engineers in 1940, and by the Geological Survey .1-1 1942. The district was examined earlier by Schafer, and the Four Chromes area is mentioned briefly by Westgate. Although the Red Ledge deposits were considered to be of minor importance as compared to those of the Stillwater Complex, several of the ore bodies were adaptable to open-pit mining' methods, and one large deposit on Line Creek Plateau was readily accessible to the Red Lodge-Cooke highway. In 1941, the U. 3. Vanadium Corp. began mining crude lump-chrome ore from the deposit on Line Creek Plateau to supplement national stockpiles, which were being depleted by the rearmament program and the disruption of chrome-ore imports by the European war. Access roads gore constricted to Hellroaring Plateau, and the mining operations were extended to that area. A gravity concentrator with a capacity of 200 tons per day was built and operated at Red Lodge to beneficiate lower-grade ore from the district.

Jan 1, 1948

By R. G. Meara, O&apos

[P.F? bmit e-ninirq ir.3.l r;tq: in the Znited State :; was u~irlyortant p~ior to the Torld ;Jar, ?-.lt with the c~r,sxti~rl of imports d11rln.c thr World 'Jar tke Rmericnn mar~factu~er:. of 1itkopone mcl Sayiun c;~oai?als forced tile tl~veloor?.ent of domertic bar,i$e dqosit9. Pr%~~,n-ily bcca-lse of tho increasing dc.n;;nl'i for lit,hupone3 by the pr?i:~t, Tlocr-covcrin~;, ,md rt1tbe.r indl~stries, ~3c.vs1o~:rnc2t of cto~entic de~onits has cr~ntim~ed to c-cpand. 13 1914, the salnr! oC doxegtic c~l~.dt? t,m-it~ ;u~cr-~nteii. to 52,91? tons, in 1237 ???,1!.1 tons nmre so1.d; thc 12:t~r rcyrprcntcd 77 .E;T pmccnt of the tot,:rl, dr??;ectic and imortcd., haritd US~C in the Cnited State? di7rinz t,hat :.vXr. C,f +he total 193,3:& ton? coy.1~-ed in the United 4 Steter ir. 135, 3E.X percent v;as usec? as groi.z.ld ~rai.te? , "0.3 percent arr lithopone, and 17 .:A ].ercc?t in the rnx 11fact,ure of b;~riim chs:nicals ]

Jan 1, 1938

By R. G. Meara, O&apos

[P.F? bmit e-ninirq ir.3.l r;tq: in the Znited State :; was u~irlyortant p~ior to the Torld ;Jar, ?-.lt with the c~r,sxti~rl of imports d11rln.c thr World 'Jar tke Rmericnn mar~factu~er:. of 1itkopone mcl Sayiun c;~oai?als forced tile tl~veloor?.ent of domertic bar,i$e dqosit9. Pr%~~,n-ily bcca-lse of tho increasing dc.n;;nl'i for lit,hupone3 by the pr?i:~t, Tlocr-covcrin~;, ,md rt1tbe.r indl~stries, ~3c.vs1o~:rnc2t of cto~entic de~onits has cr~ntim~ed to c-cpand. 13 1914, the salnr! oC doxegtic c~l~.dt? t,m-it~ ;u~cr-~nteii. to 52,91? tons, in 1237 ???,1!.1 tons nmre so1.d; thc 12:t~r rcyrprcntcd 77 .E;T pmccnt of the tot,:rl, dr??;ectic and imortcd., haritd US~C in the Cnited State? di7rinz t,hat :.vXr. C,f +he total 193,3:& ton? coy.1~-ed in the United 4 Steter ir. 135, 3E.X percent v;as usec? as groi.z.ld ~rai.te? , "0.3 percent arr lithopone, and 17 .:A ].ercc?t in the rnx 11fact,ure of b;~riim chs:nicals . ]

Jan 1, 1938

By L. E. Cardwell

This publication contains routine analyses and related source data for 390 natural gas samples from 22 States and five foreign countries. Of this total, 385 samples were collected during calendar year 1969. The remaining five analyses are of samples collected during previous years, but releases granting permission to publish the results were not received until 1969. All samples were collected as part of a continuous survey of the free world for occurrences of helium in natural gas. This survey has been conducted in the United States by the Bureau of Mines since 1917. In late 1965, the survey was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus which are described in Bureau of Mines Bulletins 4863 and 576.4 Eleven previous publications have presented the results of 8,660 gas analyses made by the Bureau of Mines Helium Activity prior to 1969. The first three, Bulletins 486,6 576,6 and 617,7 contain analyses and related source

Jan 1, 1970

By Allen D. Look

Uninterrupted shaft operations are an important economic factor in mine operation, and good shaft support is an important aid in preventing accidents and interruptions. More permanent supports can cut the hazards, costs, and delay incident to replacement of conventional timbers, especially where subject to decay. Installation of prestressed, precast concrete shaft supports in 100 feet of shaft at the Banner mine, Lordsburg, N. Mex., nave a satisfactory permanent installation in a section of shaft that had given trouble with conventional timbering. Use of rock bolts supporting gunited wire netting around the rock walls of the shaft prevented sloughing. No attempt was made in this paper to arrive at comparative costs of installation of various types of support. However, it was indicated that use of a lighter weight aggregate would be desirable in further use if prestressed precast members as placed in the Banner mine.

Jan 1, 1957

By Charles B. Carpenter

In general terminology, the West Texas Permian Basin companies the area south of the Texas Panhandle and west of the Bend Arch or Central Basin region. It is outlined more definitely by geologists however, as that area underlain by the south half of the Permian Salt Basin4/ and includes Scurry, Mitchell, Sterling, Howard, Glasscock, Reagan, Crockett, Upton, Midland, Martin, Gaines, Andrews, rotor, Crane, Pecos, Ward, Winkler, and Loving Counties in Texas, and.. Lea and Eddy Counties in New Mexico. The oil fields of the area, of which more than 70 have been discovered, are shown in fire 1. Approximately 4,200 producing oil wells have been drilled in these fields. Oil has been produced from limestones and dolomites of Permian age in most of the fields in the West Texas Permian Basin. Some of the fields produced oil from sandstone beds above the limestone, and in two fields production has been found below the limestone in formations of Ordovician age.

Jan 1, 1936

By Charles B. Carpenter

In general terminology, the West Texas Permian Basin comprises the area south of the Texas Panhandle and west of the Bend Arch or Central Basin region. It is outlined mere definitely by geologists, however, as that area underlain by the south half of the Permian Salt Basin4/ and includes Scurry, Mitchell, Sterling, Howard, Glasscock, Reagan, Crockett, Upton, Midland, Martin, Gaines, Andrews, Ector, Crane, Pecos, Ward, Winkler, and Loving Counties in Texas, and Lea and Eddy Counties in New Mexico. The oil fields of the area, of which more than 70 have been discovered, are shown in fire 1. Approximately 4,200 producing oil wells have been drilled in these fields. Oil has been produced from limestones and dolomites of Permian age in most of the fields in the West Texas Permian Basin. Some of the fields produced oil from sandstone beds above the limestone, and in two fields production has been found below the limestone in formations of Ordovician age.

Jan 1, 1936

By Wilbur A. Haley

One of the purposes of the investigation was to determine and report on how coal augers are used to mine bituminous coal that is near outcrops and may not be mined otherwise by any other present-day method. Such increased overall recovery results in the conservation of coal resources. Other reasons for the investigation were to determine and report the production rates of such operations and the types of equipment used. Auger mining of coal as a means of coal recovery supplementary to strip mining has been introduced and developed since World War II. This type of coal mining has grown rapidly, and bituminous-coal production by auger mining has been estimated at 6,000,000 tons in 1955. Mines were selected for study to give reasonably representative information on auger mining in different types and thicknesses of coal beds in different geographic areas and on different types and sizes of equipment operated under various conditions. This report is based on field studies of 8 auger-miming operations in Pennsylvania, West Virginia, and Ohio and in 5 different coal beds. Operations were observed in active strip mines, in strip mines reopened for auger mining, and along benched coal-bed outcrops. At the time of this study, no augers were reported to be operating in underground mines. The diameters of holes drilled ranged from 26 to 52 inches, and the lengths of holes ranged up to 208 feet. At some operations auger holes often penetrated abandoned underground mine workings.

Jan 1, 1957

By W. D. Mcmillan

"Magnetic surveys made by the Missouri Bureau of Geology and Mines in 931 and 1932 disclosed a large positive anomaly about a mile south of Bourbon, Mo. 3/ Electrical resistivity measurements made by the Division of Geophysical Exploration of the Bureau of Mines in the winter of 1942-43 indicated that the source of this anomaly was in the pre-Cambrian rhyolite at a depth of more than 1,400 feet. 4/In order to determine the character of the material that caused the magnetic anomaly, which might be either a body of magnetite or a large intrusive of basic rock, the Bureau of Mines drilled four holes to depths of 1,800 to 2,300 feet. Magnetite in rhyolite porphyry was encountered at 1,600 to 2,000 feet, and this is doubtless the main source of the magnetic anomaly, although it is possible that additional iron ore exists at greater depth.Hole 1 was apparently located southeast of the source of the anomaly and encountered only small stringers of magnetite. Hole 2 penetrated four mineralized zones having a total thickness of 125.7 feet and an average weighted content of 43.52 percent iron and 31.62 percent silica. These zones were tested again by a deflection hole, 2A, which gave nearly identical indications. Hole 3, 500 feet north of hole 2, penetrated 58 foot of mineralized rhyolito containing an average 43.4 percent iron.Metallurgical tests showed that the silica in the ore is tightly locked with the magnetite. After grinding to minus 100 mesh, a 66 percent iron con¬centrate with 7 percent silica was obtained by flotation."

Oct 1, 1946

By M. L. Skow

Large tonnages of the manganese ores found in Aroostook County, Maine, are refractory to conventional mineral-dressing techniques and to the common chemical- extraction procedures. The Maple Mountain-Hovey Mountain ores are typical of this type. Because the most promising method of recovering the manganese from these ores has been a chloridizing roast in which the ground ore is in contact with gaseous hydrogen chloride, preliminary batch tests were made with a fluidized bed. On the basis of these tests, it was concluded that fluidization, with careful control of operating conditions, could be employed for this cloridization and warrants further study. Selective volatilization of the iron at 600° C. was unsuccessful. An operating temperature of approximately 950° C. was necessary for a practicable rate of volatilization of manganese chloride. Hydrogen chloride contents of 10 to 100 percent of the fluidized gas gave essentially equivalent manganese recoveries with an 80- minute retention time, For shorter periods reaction was more complete with the higher hydrogen chloride concentrations. At the 80-minute retention period the lower hydrogen chloride concentrations volatilized somewhat less iron and also improved the physical operation of the process. Fluidization gave results superior to comparable tests on chloridization in a fixed bed.

Jan 1, 1956

By J. J. Dowd

1. The Pittsburgh bed is the most important bed in Marshall County, and virtually the entire production of coal in the county comes from this bed. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 tons per acre-foot of coal in place, were estimated at 3,158 million short tons as of January I, 1954. Of this total, 3,071 million short tons is in beds 28 inches and more thick. Areas in each bed except the Pittsburgh were omitted from the estimate because available data relative to the bed characteristics are too meager to make an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1956