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By Robert S. Warfield

The Federal Bureau of mines and U.S. Geological Survey conducted exploratory investigations and geologic mapping in the Wishbone Hill district of the Matanuska coalfield almost continuously from 1942 through 1958. These investigations delineated reserves of high-volatile bituminous coal necessary to supply the rapidly expanding military and civilian requirements in the Anchorage area. This report describes the program conducted by the Bureau of Mines from 1949 through 1958, and briefly summarizes previous investigations, the results of which have already been published. The coal-bearing structure on both the north and south limbs of the prominent Wishbone Hill syncline was explored by 8,719 feet of churn drilling and 25,460 feet of diamond-core drilling. A total of 33 holes were drilled ranging in depth from 60 to 2,114 feet. To supplement the drilling operations, bulldozer and dragline trenching were undertaken at key locations; about 25,000 cubic yards of dragline trench were excavated in the vicinity of the old Premier mine.

Jan 1, 1962

By John C. Machisak

Employment and related injury experience of the coking industry in the United States for 1957 contained in this publication is summarized under three general sections: (A) General injury experience: Tables 1 to 9: Current and comparable statistics on operating data, number, frequency, and degree of severity of injuries and major accident agencies involved in the cause of Injuries. Data are presented for the industry as a whole, for each type of oven, and for the States in which coke was produced.

Jan 1, 1959

By R. M. Santmyers

Of the sand and miscellaneous silica produced in the United States , ordinary sand and gravel are , of course , the most important, at least as regards volume of output . The building- construction industry absorbs approximately 75 per cent of the total value of all quartz and silica , as shown in Table 2 of Quartz and Silica, Part I, under "General summary . " Because of their unusual physical properties tripoli and diatomite find extremely wide uses in industry, and as the commercial deposits of these ninerals , especially tripoli , are scattered, large quantities enter into interstate commerce . Whereas ordinary sand and gravel are bulky commodities , these specialties have a fairly high unit value and hence can be transported relatively long distances .

Aug 1, 1931

Kroemer(1-3) and Kroemer et al.(4) define the isoinertial technique of strength assessment as one in which mass properties of an object are held constant, as in lifting a given weight over a predetermined distance. Several strength assessment procedures possess this characteristic. Most commonly associated with the term is a specific test developed to provide a relatively quick assessment of a subject's maximal lifting capacity using a modified weight-lifting device.(1,5) The classic psychophysical methodology of assessing maximum acceptable weights of lift is also considered an isoinertial technique under this definition.(6) While the definition provided by Kroemer(1) and Kroemer et al.(4) has been most widely accepted in the literature, some have applied the term "isoinertial" to techniques that differ somewhat from the preceding definition, such as in a description of the Isotechnologies B-200 strength testing device.(7) Rather than lifting a constant mass the B-200 applies a constant force against which the subject performs an exertion. The isoinertial tests described here apply to situations in which the mass to be moved by a musculoskeletal effort is set to a constant. Is Isoinertial Testing Psychophysical or Is Psychophysical Testing Isoinertial? As various types of strength tests have evolved over the past few decades, some unfortunate developments in terminology have arisen to describe and classify different strength assessment procedures. This is particularly evident in sorting out various tests that have been labeled "isoinertial." One example was cited earlier. Another problem that has evolved is that the term "isoinertial strength" has two connotations. The first is the conceptual definition: isoinertial strength tests include any strength test in which a constant mass is handled. In practice, however, the term is often used to denote a specific strength test in which subjects' maximal lifting capacity is determined using a machine and a constant mass is lifted.(1,5) Partially as a result of this dual connotation, the literature contains references to both "isoinertial strength test" as a psychophysical variant(8) and the psychophysical method as an "isoinertial strength test" (4,9) To lay the framework for the next two chapters, the authors will briefly discuss some operational definitions of tests of isoinertial and psychophysical strength. In stating that the isoinertial strength test is a variant of the psychophysical method, Ayoub and Mital(8) refer to the specific strength test developed by Kroemer(1) and McDaniel et al.(5) Clearly, this isoinertial protocol has many similarities to the psychophysical method: both are dynamic; weight is adjusted in both; and both measure the load a subject is willing to endure under specified circumstances. However, while both deal with lifting and adjusting loads, there are significant differences between the psychophysical (isoinertial) technique and the Kroemer-McDaniel (isoinertial) protocol in their procedures and the use of the data collected in these tests. For our purposes, we designate the

Jan 1, 1998

By C. C. Popoff

The development of glass-making industries in the Pacific Northwest as well as other industries that use pure silica has been retarded by lack of local supplies of low-cost raw material. Several quartz deposits along the Skagit River constitute the only known source of relatively pure silica within the range of cheap transportation to the Seattle industrial area. Although some silica has been mined from these deposits, very little information regarding their size, grade, and other physical characteristics has been available to the general public. As a part of its program of investigation of the mineral resources of the Pacific Northwest, the Bureau of Mines assigned the writer to examine the Skagit River silica deposits in October 1946. This report presents the factual data obtained from an examination of the so-called Stoner, Bacon Creek, and Pressentin deposits. These deposits are the largest and most easily accessible known to exist in the area. The deposits are near Marblemount, which is on State Highway 17A. They are within 1 mile to 1-1/2 miles of the Skagit. River Railway, which provides transportation to Seattle, a distance of 130 miles. None of the deposits has been developed thoroughly. The Stoner deposit, however, has been developed by a quarry about, 5,0 feet square and has been exposed by hydraulic removal of the overburden throughout a distance of 180 feet along the hanging wall of the vein

Jan 1, 1949

By T. A. Lang

Concepts and equations have been developed to quantitatively determine the stability of a rock bolted coal mine roof as a structural (beam-arch) member consisting of reinforced rock units. The equations take into account: rock bolt tension, length, spacing, and orientation; size of opening, strength and physical properties of the rock; and loads from distressed rock, and were critically reviewed using sensitivity analyses and the results available from relevant previous analytical and physical model investigations. It is concluded that they can essentially be validated by using small scale physical models and the full size mine entry model at the USBM Spokane Research Center. However, a comprehensive research program, including analytical and laboratory investigations and field trials in typical mines, will be required to define and validate criteria and standards for using the equations as a basis for a rational design code for rock reinforcement installations to replace the semi-empirical rules now being used. For example, these studies have shown that the practice of installing vertical roof bolts with a uniform spacing equal to the bolt length is inherently unsafe and that the spacing should be reduced near the walls to prevent shear failure of the roof strata. The development of such a rational design code would provide enhanced safety in coal mining operations and warrants a high priority in the Bureau's ground control research program.

Jan 1, 1981

By Geoffrey C. Huggins

Diagnostic: tests were performed on a production ST-5A Load-Haul-Dump machine manufactured by Wagner Mining Machinery Company to evaluate and rank order noise sources. The diagnostic evaluation indicated that the major noise sources were the transmission, the engine, and the cooling fan. This phase was followed by implementation of recommended noise control treatments, which included vibration isolation of the transmission, a transmission enclosure, an engine enclosure, and modifications of the inlet to the cooling fan. The final step in the program was an underground operational period which began on 31 August 1976 at the National Gypsum Mine in Shoals, Indiana. The noise control treatments successfully reduced the LHD operator noise exposure by 7 dB(A), thus increasing its allowable operation time by a factor of 2.7. Actual measurements made underground using noise dosimeters have indicated that, during, a typical shift, the noise control treatments have reduced the fractional exposure to an allowable level. The report discusses the mechanical aspects of the LHD, its noise sources, the treatments applied, the final levels achieved, and field experience with the noise-controlled machine.

Jan 1, 1977

By Michael R. Yenchek

The U.S. Bureau of Mines investigated the performance of portable power cables under transient conditions. This research had a twofold purpose: (1) to define the thermal characteristics of electrically overloaded trailing cables, and (2) to conceptualize electrical protection for cables that allows maximum cable efficiency without diminishing electrical safety in underground mines. Several tasks were undertaken in support of these goals during the 3-year research effort. Overload tests ranging from 2 to 12 times rated ampacity were conducted in the Bureau's Mine Electrical Laboratory. Two thermal models of energized type G-GC trailing cables were constructed, one based on thermodynamic theory and the other using empirical data from previous Bureau load tests. The empirical model was then incorporated into an interactive computer program that can assist designers and approvers of mining machines in selecting the appropriate size trailing cable. This program can be the basis for a cable protection system that ensures that cables are not the source of fires, ignitions, burns, or explosions underground.

Jan 1, 2010

By Parry. V. F., W. S. Landers

"INTRODUCTION Approximately 1,250,000 tons of 2-1/2-inch and 1-1/2-inch slack, representing over half of the output from 40 to 50 mines, is produced in the Denver region each year. Part of this slack is made by crushing lump, and some of it is rescreened to make pea and modified pea sizes measuring 1-1/2 inches by 2-1/2 inches and 3/4-inch by 1-1/2 inches, round-hole. Modified pea is popular as domestic stoker fuel. Approximately 900,000 tons of slack 0 by 2-1/2 inches, 0 by 1-1/ 2 inches, and 0 by 3/4-inch in size are consumed by industrial plants, the principal consumers being a large power plant and the beet-sugar industry. The power plant uses annually 250,000 to 275,000 tons of pulverized fuel and can pulverize slack of any size, while the sugar factories consume about the same quantity of coal in stokers. The sugar factories store about 110,000 tons of 2-1/2-inch slack under water from January to October, and burn the remainder of their consumption directly during the campaign season from October to December. For this purpose, sugar-factory power plants can use any size of slack, which is recrushed to pass a 3/4- or 1/2-inch screen before burning on chain-grate stokers. About one-third of the 2-1/ 2- inch slack produced in the field is used in smaller industrial plants that employ stokers.Certain factors affect the utilization of 2-1/2-inch slack in the Denver region. The increasing production of hydroelectric power has reduced the consumption of coal at power plants slightly. If more hydropower is generated, the trend of consumption of slack might be downward, unless industrial activity offsets this greater output. Rapid increase in number of domestic stokers during recent years has necessitated preparation of greater quantities of stoker coal, with the result that more lump is crushed, and preparation facilities are changed. At present about 19 percent of the coal produced is crushed to meet the constant demand for industrial fuel as well as the increasing but variable demand for the small domestic stoker sizes. The quantity crushed has increased 12 percent during the last 6 years. These factors are shifting constantly. The trend toward the use of clean and smaller sizes for domestic stokers gives a slack having a larger proportion of fines. In future, even greater quantities of small stoker coal probably will be prepared, and the resulting greater quantities of small slack will have to be used for industrial purposes."

Aug 1, 1942

By A. T. Iannacchione

Roof-rock instability in advancing sections of underground coal mines is a major contributing factor to accidents resulting in fatalities and injuries. Such roof-rock conditions can also result in loss of production due to additional cleanup time and increased amounts of reject material. The Bureau of Mines is investigating fundamental geologic factors affecting coal mine roof-rock instability in order to develop techniques to predict zones of potential unstable roof-rock. Two distinct directional trends of unstable shale roof-rock in a mine working the Upper Kittanning Coalbed are delineated: one trend is associated with the sandstone-shale transition zone, the other with a fault system. The unstable shale roof-rock associated with the transition zone, a consequence of differential compaction, is comprised of slickensided roof-rock. Whereas, the unstable shale roof-rock associated with the fault system, a consequence of structural deformation of the strata, is comprised of fault planes. These faults, small in comparison to the sandstone-shale transition zone, are difficult to delineate with a standard drilling program. Trends of the transition zone associated with the sedimentary facies change are projected into unmined portions of the coalbed with the aid of exploration core data.

Jan 1, 1981

As part of the Phase I study activity, a questionnaire was sent to a representative sampling of mining companies to obtain information on the uses, use conditions, personnel policies and other user concerns associated with front-end loaders. On-site visits to several of the mining companies were also parried out and the questionnaire was used during these visits as well. Five major areas were dealt with in the user questionnaire. These included: 1) Front-End Loader Critique - An open-ended form was employed to permit the mining companies to describe the particular things they liked and disliked about front-end loaders, in general, and/ or specific models in particular. 2) Usage - A form indicating the functions performed by front-end loaders and the numbers, makes and models of front-end loaders being used by mining companies. 3) Environment - A form where the user indicated the various types of conditions encountered in their use of front-end loaders. 4) Personnel - A form for describing factors pertaining to the qualifications of front-end loader operators. 5) Miscellaneous and Comments - A form permitting the user to comment on his feelings toward standardization of front-end loader operator stations.

Jan 1, 1973

By S. M. Shelton, W. A. Calhoun

"INTRODUCTION Discovery and development of a southwestern Arkansas quicksilver district are recent history. In July 1930 4/, a specimen was discovered near the Little Missouri River in sec. 1, T. 7S. R. 26 W., which was identified as cinnabar. In the summer of 1931, Leo Yount began prospecting for cinnabar near the Little Missouri River. In the fall of that year he operated a small three-tube retort near the present Parker Hill mines and produced several flasks of quicksilver. Yount optioned a considerable block of ground containing the best showings in the Little Missouri River area, and on February 19, 1932, he and W. C. McBride, Inc., of St. Louis, Mo., formed the Southwestern Quicksilver Co., which was the largest producer in the district until operations ceased in September 1934.The Southwestern Quicksilver Co. installed a rotary furnace on Parker Hill in April 1932, which treated ore from the three principal mines Gap Ridge, Parker Hill, and Parnell Hill. In 1934 production was entirely from the Gap Ridge and Parker Hill mines. Nothing was done at Parnell Hill except a little small-scale work on a share basis.Mercury Producers, Inc., later took an option on the holdings of the Southwestern Quicksilver Co. and in June 1935 began operations. The company produced considerable quicksilver before the lease and option were surrendered in the summer of 1936. Most of the work of Mercury Producers, Inc., was on Parnell Hill, but some work was done on Parker Hill and at the Bell prospect on ground not controlled by the Southwestern Quicksilver Co."

Mar 1, 1942

By Tracy. L. D.

"Since the introduction of pulverized coal as a substitute fuel for natural gas in the various types of heating furnaces used, in steel mills, a number of fires and explosions have occurred, resulting in the loss of life and property.As one of the primary functions of the Bureau of Mines is to conduct investigations in the utilization of mineral substances with a view to increasing safety in the use thereof, it was deemed advisable to investigate the hazards involved in the industrial use of pulverized coal and, if possible, to devise methods of preventing future accidents arising therefrom. The knowledge of the explosive qualities of coal dust which the Bureau has gained in studies affecting dust explosions in coal mines was of material assistance in these investigations.Several plants were visited in which either fires or explosions had occurred, and data obtained as to the probable cause of the accidents.There was found to exist, among some of those employed about the furnaces, a lack of knowledge of the explosive and inflammable qualities of powdered coal.A small stream of pulverized coal leaking down from a defective joint in a coal transport line did not attract much attention, whereas, had a leak in a natural gas line occurred -wider similar circumstances, no doubt it would have had immediate attention.As a matter of fact, if by any means the duet cloud should come in contact with an open flame or hot metal, the effects would be as disastrous as if it had been gas.This is exceedingly well illustrated by an accident which came to the writer's attention. In the system used at this particular plant, the pulverized coal is transported to the furnace through compressed-air lines. The fuel is fed from a storage bin to a blowing tank in quantities as desired, after which compressed air is admitted and the powdered coal blown to the furnaces. At the time of the accident some repairs were being made to the tank, and it was supposed that the air pressure had been entirely released as the pressure gage stood at zero. There was, however, one or two pounds air pressure remaining and when one of the connections was taken off, a cloud of dust was blown across the room, 30 or 40 feet towards the drier furnace where it came in contact with some live coals. Immediately the entire room was filled with flame which rolled back and forth over a specs 50 feet or so in length."

Apr 1, 1921

By W. W. Adams

"The results of the fourth annual safety contest, 'mown as the National Safety Competition, contacted by the United States Bureau of Mines are herein announced. A bronze trophy, ‘Sentinels of Safety’, the gift of the Explosives Engineer magazine, has been awarded to the leading mine in each of the five groups into which the mines and quarries that participated in the contest were arranged. These five groups were: anthracite mines, bituminous coal mines, metal mines, nonmetallic-mineral mines, and carries and open-pit mines. The leading plant in each group was the mine whose employee lost the smallest number of days from accidents in proportion to the total number of man hours worked. Where two or more mines operated without a lost-time accident, the winner was adjudged to be the plant which operated the largest number of man hours during the year.The contest was based upon reports of accidents and exposure sent by the competing companies to the Bureau of Mines. Records of the five leading companies in each group were made known to a Committee of Award, consisting of the following seven members: H. Poster Bain, Secretary of the American Institute of Mining and Metallurgical Engineers; James F. Callbreath, Secretary of the American Mining Congress; W. H. Cameron, Managing Director of the National Safety Council; H. L. Gandy, Secretary of the National Coal Association; A. T. Goldbeck, Director of the Engineering Bureau of the National Crushed Stone Association; William Green, President of the American Federation of Labor; and A. J. R. Curtis, Assistant to the General Manager of the Portland Cement Association. Members of the committee voted for the winning company in each group in accordance with the rules governing the contest.. A majority vote prevailed."

May 1, 1929

By H. W. Kilau

The Bureau of Mines evaluated synthetic fluorspars as substitutes for natural fluorspar in basic oxygen steelmaking using a high-temperature rotational viscometer and a quarter-ton basic oxygen furnace (BOF). Consider-able variation in stability and BOF slag fluidizing properties were found when using the initial synthetic products, but improved synthesis methods produced synthetic fluorspars that were generally comparable to natural fluorspar in laboratory testing. Trials in the furnace showed the synthetic products to be operationally the equivalent of natural fluorspar. Higher sulfur and phosphorus contents in some of the synthetic materials did not adversely affect the steel chemistry. Analyses of wet scrubber samples showed evidence that the pelletized synthetic fluorspars experienced greater physical and chemical disintegration than did natural fluorspar. It was also found that operation of a BOF without fluorspar is possible when making low-carbon steels because iron oxide is intrinsically generated as the slag fluidizer.

Jan 1, 1981

By Wilton Johnson

Native asphalt was produced in 1981 by five companies in three States, Alabama, Texas, and Utah. Texas was the leading State in production of native asphalt. Total production increased in 1981 to 1.26 million tons, while value increased 10.5% to $27.7 million. Bituminous limestone, used primarily for street and road repair, was produced by Whites Uvalde Mines and Uvalde Rock Asphalt Co., both in Uvalde County, Tex., and Southern Stone Co., Colbert County, Ala. Gilsonite was produced by American Gilsonite Co., Uinta County, Utah, and Ziegler Chemical and Mineral Corp., Weber County, Utah. This material was used for purposes other than road repair.

Jan 1, 1982

By Boyd Guthrie

Methods of distilling topped crude oils and distillates under vacuum, accompanied by good fractionation, have taken a place of major importance in the refining industry. In the refining of petroleum products it is generally desirable to produce a distillate of good quality, and this objective is attained by fractionation of a high degree. The laboratory and commercial practice have proved that by varying the amount of fractionation the quality of the distillate can be changed, and refiners are cognizant of the advantages of good fractionation. Distillation under high vacuum, however, is a relatively new practice in petroleum refining, and only during the last few years has there been an indication that this method may become a general practice in the industry. Vacuum distillation offers many advantages over older methods of distilling petroleum products. Vacuum combined with steam distillation, for example, is replacing straight-steam distillation because the quality of the products of vacuum and steam distillation surpasses that of those produced by straight-steam distillation. Although the injection of varying amounts of steam in a vacuum unit is common practice, the amount of steam used is becoming loss as the vacuum within the unit is increased. This report describes the construction of a visible-action laboratory batch still and fractionating column and gives certain data pertaining to the operation of the apparatus under vacuum for the production of lubricating distillates. The apparatus was designed and built to produce lubricating distillates under as nearly ideal conditions as possible, in order that a subsequent study of the characteristics of the distillates could be made. For example, a study could be made of the distillates obtained up to the point of cracking of the charge if a topped crude were charged to the still; if the still was used as a rerun unit for lubricating distillates a study of nearly the entire charge could be made. Only topped crude has been charged to the still so far, and therefore this paper is limited to the results obtained from the distillation of such a charge. The results so far obtained indicate that such an apparatus is valuable in a study of different crude petroleums as sources of lubricating distillates.

Jan 1, 1932

By P. Nicholls

[This paper sets forth the burning characteristics of coke used as a domestic fuel as shown by work of the U. S. Bureau of Mines and others. Coke is a truly smokeless solid fuel and is held in high regard for this quality. Ways are being found for making commercial coke from a wider range of cools than heretofore, and tale use of coke for domestic heating is increasing. ACKNOWLEDGMENTS The experimental work reported in this paper was conducted at the Pittsburgh Experiment Station of the U. S. Bureau of Mines cinder the authority of O. P. Hood, chief mechanical engineer; M. L. Orr, assistant feels engineer, and W. M. Brewer, junior fuels engineer, assisted by Charles Schramm cooperated in making the tests.]

Jan 1, 1929

By Donna L. Anderson

This information circular documents the status of a laser-based guidance system to track and control the tramming maneuvers of a continuous mining machine. The work is part of a multiple project effort at the U.S. Bureau of Mines to develop technology for computer-assisted mining systems. The system includes stationary offboard laser-scanning sensors that report the angular coordinates of retroreflective targets on the mining machine. A microcomputer system processes the angular coordinates, determines position and heading, handles requests for data, and controls tram maneuvers of a continuous mining machine. This report describes the hardware for the sensor and computer systems and the software algorithms for continuous miner position and heading determination, closed-loop tramming, and data request handling. Improvements made to the system since previous documentation include the rewriting of the software on a stand-alone real-time microcomputer system, the implementation of real-time programming techniques, the use of a new version of the laser sensor, and the design and development of explosion-proof enclosures for the lasers and corresponding power supply.

Jan 1, 1991

By W. N. Marchant

The Bureau of Mines performed chemical research to elaborate details of sulfur chemistry pertaining to the citrate flue gas desulfurization process in which sulfur dioxide (SO2), absorbed (as bisulfite ion) in a buffered sodium citrate solution, is reduced by hydrogen sulfide (H2S) according to the overall reaction 2H2S + HSO3 + H+ ? 3S + 3H20. The rate-limiting step in the process was shown to be the reduction by H2S of thiosulfate (S2031-) that is formed as an intermediate. Pseudo first-order kinetic measurements were made at room temperature to retard the reaction sufficiently that adequate analysis was possible. These measurements showed the rates of the following net processes to be -d [S02]/dt (pH 4.5) = (0.409±0.050)min-1 [S02]; d [S2032-]/dt (pH 4.5) = (0.199±0.017)min-1 [S02]; -d [S2032-]/dt (pH 4.0) = (0.0437±0.0265)min-1 [S2032-]~1; -dH2S/dt (pH 3.9) = (21.6±3.0) mmoles/min-atm [H2S]g1.4, where [H2S]g is the partial pressure of H2S in the gas phase, in atmospheres, and the rate describes the consumption of H2S, in millimoles per minute; d[S]/dt (pH 4.0) = (38.0±3.4)min-1 [H2S]1, where [H2S] is the concentration of H2S in solution. Hydrogen ion consumption during the slow phase of regeneration was shown to occur at (2.1±0.5) times he rate of thiosulfate consumption, which is interpreted as evidence for the following as the rate-limiting reaction: 2H2S + S2032- + 2H+ ? 4S + 3H20 A scheme consisting of five sequential general reactions is proposed to account for sulfur formation.

Jan 1, 1981