Search Documents

Control shearer-generated airborne respirable dust on longwall mining sections. Approach Previous Bureau studies have shown that using high-pressure water can have a significant impact on the amount of airborne dust released into the face airflow while cleaning and controlling the airflow in the immediate cutting zone. The basic concept to improve the drum water spray system was to utilize high-pressure (1,200 psi) inward-facing drum sprays to improve the dust knockdown efficiency of the spray system and confine the dust to the face area. This system would minimize the exposure of the shearer operator through dust avoidance and decrease face dust levels by suppressing the amount of respirable dust that becomes airborne. System Design In-mine tests were designed to provide information that would permit evaluation of the operation with different spray orientations and water spray pressures. This was achieved by comparison with a conventional baseline wet-cutting system consisting of 26 low-pressure bit sprays, located on the hit blocks to provide pick-point flushing. Total drum water flow was 60 gpm and was maintained continuously throughout all tests. The high-pressure inward-facing drum water spray system consisted of sprays located in each bit block, oriented 15° and 30° toward the face. The inward-facing water spray system was operated at either 800 or 1,200 psi.

Jan 1, 1989

By Charles L. Kimbell

The final 26 tables of this chapter, tables 14-39, extend and expand the statistical series on production that was started in the 1963 edition of the "Area Reports: International" volume of the "Minerals Yearbook" and that was subsequently updated and expanded in the 1965 and 1967-88 editions. In this year's edition, for the first time, a column has been added to each of these tables providing a 5 year average for 1985-89, inclusive. This should provide a clearer picture more rapidly of the role of each major producer over the 5-year period. The listing order of major producers, however, continues to be, as in past years, in descending order of rank in the year of review, 1989. With the inclusion of silver and uranium oxide in the 1988 edition of this chapter, this group of tables now includes each of the crude minerals that ranked from 1st to 19th in 1983 in terms of value of their output (as well as four others of lesser rank). These 23 crude mineral commodities accounted for 93% of the estimated value of world crude mineral of world crude mineral production in 1983. In addition, world output of five key down-stream products-aluminum, steel, cement, nitrogen in ammonia, and refined oil are included because of their significance as products.

Jan 1, 1992

Major activities of the Bureau of Mines Explosives Research Center during fiscal year 1965 (July 1, 1964, to June 30, 1965) are reviewed briefly. Part 1 summarizes significant accomplishments of the projects that were active during the report period. Part 2 presents short abstracts of the publications that appeared in the Bureau series and in other media during fiscal year 1965. Publications issued after June 30, 1965 are noted where pertinent in footnotes but are not abstracted. ACKNOWLEDGMENTS The Bureau of Mines gratefully acknowledges the support given through cooperative agreements by the following organizations to investigations con¬ducted by the Explosives Research Center during fiscal year 1965: Dow Chemical Company Manufacturing Chemists' Association Monsanto Chemical Company The Sulphur Institute

Jan 1, 1966

By J. S. Webb

This is one of a series of papers dealing with mining methods, practice, and costs be¬ing published by the United States Bureau of Mires. In this paper a description of the mining practice in vogue at the Braden unit of the Kennecott Copper Corporation is undertaken. PRODUCTION At present (1931) the entire production of ore is being obtained from the Teniente mine. The miring method in use is an adaptation of block undercutting which has been a development of the stoping and pillar caving experience obtained at this property. Improvements in mining practice are constantly being made.

Jan 1, 1932

By Christopher Mark, Robert J. Tuchman

This proceedings volume contains papers presented at technology transfer seminars sponsored by the National Institute for Occupational Safety and Health (NIOSH) on New Technology for Ground Control in Retreat Mining. The seminars were conducted at five locations: Uniontown, PA (March 26, 1997), Norton, VA (April 8, 1997), Pikeville, KY (April 10, 1997), Charleston, WV (April 17, 1997), and Evansville, IN (April 22, 1997). The papers presented here describe several new, highly practical technologies developed by the NIOSH Pittsburgh and Spokane Research Centers3 to improve safety during pillar retreat operations. Two central issues are addressed: pillar design and mobile roof supports (MRS's). Proper pillar sizing is essential for safe pillar extraction. The Analysis of Retreat Mining Pillar Stability (ARMPS) program and its large data base of actual mining case histories are presented. LAMODEL, a second computer program, can be used for analysis of multiple-seam and other complex mining situations. Other papers address pillar design to avoid massive pillar collapses and the proper role of coal strength testing. MRS's have greatly improved safety where they are used for pillar line support. We studied the application of MRS's at 20 mines throughout the Eastern United States. Conclusions regarding the most effective section layouts, cut sequences, and support placements are reported. Field and laboratory tests of MRS's are also described.

Jan 1, 1997

By Francis E. Federspiel

A mineral purvey of the Granite Chief RARE II area (A5-261), covering about 23,400 acres (9,470 ha) of Tahoe National Forest and the Like Tahoe Management Unit, was conducted by the U.S. Bureau of Mines and the U.S. Geological Survey in 1979 and 1980 (fig. 1). The investigation by the Bureau of Mines indicates that the area has a low potential for mineral resources. Samples taken from prospect pits and favorable outcrops indicate no minable quantities of precious or base metals. Placer deposits are too small and low grade to be considered a resource.

Jan 1, 1981

By J. Wade Watkins, Joseph W. Horne, Arthur Matzick

"A successful procedure for the recovery of a valuable product from weathered tank-bottom settlings has been developed in the laboratories of the Bureau of lines and used in a field pilot plant. These heavy emulsion settlings, generally regarded by the industry as waste material, have usually been drained into open pits or storage ponds and eventually destroyed.Laboratory examination of the waste material shows it to consist essentially of a ""water-in-oil"" emulsion containing a considerable volume of congealed ""paraffin."" This paraffin is mainly high-melting-point wax; known in the industry as microcrystalline wax, for which there is an increasing demand.Because of the physical properties of this wax, the tank-bottom settlings are not responsive to conventional methods used for demulsifying ordinary crude-oil emulsions.The work upon which this report is based was conducted by the Bureau of Mines in cooperation with -the Kansas State. Board of Health and with special cooperative agreements-with the Cities Service Oil Co, Bartlesville, Okla., and the Bareco Oil Co,. Barnsdall, Okla. The studies were made under the general supervision of R. A. Cattell, chief engineer, Petroleum and Natural-Gas Division, Bureau of Mines, Washington; D. C., and H. C. Fowler, supervising engineer, Petroleum Experiment Station, Bureau of Mines, Bartlesville, Okla., and under the direct supervision of Ludwig Schmidt, senior petroleum engineer, Bureau of Mines, Bartlesville, Okla.Gratefully acknowledged are the assistance and cooperation given by the Cities Service Oil Co. of Oklahoma and especially by M. J. Kirwan, manager of production, and by Q. E. Beecher, general superintendent of production, Bartlesville, Okla., and to members of their staff at Oil Hill, Kans.The assistance and suggestions of V. R. Oakley, general superintendent, E. R. Wiles, director of research, L. G. Willis, field engineer in charge crude-oil supply, and Gerald DeWalt, chief chemist, and his staff of the Bareco Oil Co., Barnsdall, Okla., were of much value in the laboratory and recovery work."

Mar 1, 1946

By Richard L. Rains

In 1992, the Bureau of Mines evaluated mineral resources of the 34,043-hectare Caribou City and 41,943-hectare Stump Creek study areas in southeastern Idaho. No resources were delineated. The areas had been proposed for wilderness. Rocks underlying the study area are part of the Idaho-Wyoming Thrust Belt. At Caribou Mountain they have been intruded by diorite-monzodiorite. Where the intrusive rocks contact calcareous members of the thrust belt, skarn bodies have formed that host metal deposits. Gold, both placer and lode, occurs in the Caribou City area, and salt occurs in the Stump Creek area. Production records show 73.5 kg (2,363 ounces) of placer gold were produced; however, field studies indicate more than 2,000 kg (67,000 ounces) probably were recovered. Minor amounts of lode gold, silver, and copper were recovered from the hard rock mines. Production of salt from the Stump Creek study area in the 1860's was used by emigrants on the Oregon trail and also shipped to various mining districts for use in silver recovery. Oil and gas were drilled for, but all holes are plugged and abandoned. There are no current leases. Examined workings consisted of 25 adits, 3 shafts, 50 prospect pits, and extensive placer workings all in the northern tip of the Caribou City area, Current BLM records show 168 placer and 146 lode claims; 14 claims are patented.

Jan 1, 1993

By David R. Peterson

This user's manual covers a set of 5 computer codes which were generated during development of a simulation of deep ocean mining operational economics. Table 1.1 provides a summary of these codes, and a more thorough description of each follows, In addition to the descriptions in this user's manual, internal documentation is provided throughout each code, except for the very simple ones, for ease of understanding or possible modification. The two major codes are MINER, which performs the deep ocean mining system operational simulation, and MSWEEP, which calculates the sweep and feed efficiencies for a set of collector paths generated by MINER. The standard operating procedure is to input the system and operating parameters to MINER, which computes a set of collector paths automatically and stores the information in the fife PATH.DAT. MSWEEP subsequently retrieves the collector path data in PATH.DAT, and uses it to calculate sweep and feed efficiency. Separating MINER and MSWEEP allows parmetric execution of MSWEEP without recomputing the collector paths with MINER. PIPEST, RESP, and OBSTCL are special-purpose codes described in more detail in the following documentation.

Jan 1, 1979

By B. G. H. Thomas, W. P. Yant, A. C. Fieldner, R. R. Sayers, W. J. McConnell

"One of the outstanding problems confronting automotive engineers in attempting to construct motors of greater economy is that of eliminating the ""knock"" from the operation of the engine. Recent investigations of this detonation or knock in internal-combustion engines, especially of the high-compression type, have demonstrated that it can be eliminated or reduced by decreasing the reaction velocity of combustion by adding small quantities of certain compounds to the gasoline, This makes it possible to use engines of a higher compression ratio, thereby greatly increasing the mileage per gallon of gasoline consumed. The savings in fuel reserves from increasing the proportion of crude oil marketable as motor fuel and in permitting the designing of more efficient engines are obvious.Ethyl gasoline, one of the widely used anti-knock fuels, is ordinary motor gasoline to which has been added 3 c.c. of tetraethyl lead and 2 c.c. of a halogen carrier, as ethylene dibromide or trichiorethylene, or approximately 0.06 per cent of the lead compound and 0.04 per cent of ethylene dibromide by volume. Ethyl gasoline should not be confused with ethyl fluid, which is a mixture of concentrated tetraethyl lead and ethylene dibromide in the prowler proportions for mixing with gasoline, but is not a motor fuel and is not sold to the public. Also tetraethyl lead is not a motor fuel, and likewise is act sold to the public."

Dec 1, 1924

By Richard C. Moore

The U.S. Bureau of Mines contracted a study to estimate what effects the underground mining of thick coal seams in the western United Slates would have on the surrounding water resources. Potential coal fields in the western United States where this type of mining might occur were identified. The foreign literature was searched for studies of effects on hydrology from thick seam underground coal mining. Based on the limited information obtained from the foreign literature, estimates of the effects of this type of mining on the ground and surface water in the western states were made.

Jan 1, 1980

By W. P. Yant

Canister-type gas masks Pave become an essential part of the equipment of many industries, not only for use in .emergencies, but also in performing normal operations of industrial processes and procedures, particularly where ventilation is not practically or economically feasible. They are also used widely for enhancing safety of operations which previous to the development of gas masks had been performed in harmful atmospheres. Since the inception of industrial gas masks the Bureau of Mines has been actively engaged in endeavoring to increase the efficiency and safety of these devices, and this bureau bas become a source of advice to manufacturers in producing devices of good quality and to industry in the proper selection and use of these devices. In order to give first-hand information and keep current with the demands and needs of industry it is necessary to perform investigations from time to time. This report deals with tests of certain types of commercial gas-mask canisters for protection against mercury vapor.

Jan 1, 1932

By George Watkin Evans

The United States Geological Survey has estimated 1 that the State of Washington contains 11,412,000,000 tons of bituminous coal and 52,442,000,000 tons of subbituminous coal, in beds more than 14 inches thick. As the present rate of production is about 4,000,000 tons a year, Washington apparently contains coal enough to supply Pacific coast markets for many years. The character of the coal beds of Washington renders the production of clean coal very difficult, and a considerable proportion of the output is washed before it is marketed. In 1915 Washington ranked fifth among the States in the amount of coal washed, though only twentieth in total output. In that year 37.9 per cent of the coal produced in the State was treated in surface cleaning plants. On account of extensive folding and faulting of the coal measures, mining in Washington presents many difficulties; therefore a description of the methods employed at some of the mines may be useful in planning operations in other regions, and is presented in this bulletin. The coals of Washington differ in quality, ranging from true lignites in Cowlitz County in the southern part of the State to anthracites in the Mount Baker district of Whatcom County, in the north~ rn part. Most of the output consists of subbituminous and bituminous coals, the latter including both coking and noncoking varieties. Analyses of the coals of the State and descriptions of the beds from which the samples were taken have been printed in publications of the United States Bureau of Mines.2 Details of coal beds and analyses of the coals of King, Kittitas, and Pierce Counties have also been published by the Washington Geological Survey; 3 and most of the coal beds of the State are described in some detail in a bulletin of the United States Geological Survey.4 In 1918 mining was in progress at 72 mines in the State 4a; 46 of these mines each employed more than 10 men underground. These mines were distributed as follows: Thurston County, 1; Lewis County, 7; Kittitas County, 14; King County, 16; Pierce County, 6; Skagit County, 1; and Whatcom County, 1. During that year a total of 5,847 men were employed, 4,172 underground and 1,675 on the surface. The average number of days worked in the State was 275, and the average yearly output per man was 706 tons. Coke is made only in Pierce County by four companies, which have a total of 341 beehive ovens. In 1918 they produced 93,699 tons of coke. Up to 1919 mining machines were little used in the State. In 1917 only 6.61 per cent of the coal :produced was undercut by machines. In that year 58.95 per cent of the coal was mined by hand, and 34.44 per cent was shot off the solid. The explosives used were as follows: Black powder, 36.6 per cent; dynamite, 38.l per cent; and permissible, 25.3 per cent. The State of Washington is divided naturally into two parts by the Cascade Mountains which extend north and south somewhat west of the middle of the State. The coal areas east of the range will hereafter be referred to as eastern Washington-though nearly all of it is west of the middle of the State-and that on the west side as western Washington. The geographical distribution of the coal fields is shown in Plate I. Exploration of the State has not been exhaustive enough to preclude the possibility of discovering, besides the foregoing, other districts that contain deposits of coal in commercial quantities.

Jan 1, 1924

By L. A. Morley

Volume III of the final report examines the indication versus interruption procedures used on motion-drive power equipment, with emphasis on surface excavators. The report begins with a review of the electromechanical acid conversion used with the Ward-Leonard control system. Protection criteria for the drive-system components are then discussed. Fault sources and fault calculations for both the ac supply source and dc power loop are introduced to assist in discussing indication and interruption procedures. The subject is then expanded to examine the dynamic process of the machine and determine the effects of fault current and position of the machine to allow for an orderly shutdown. With this analysis, possible indication an interruption procedures are given for the four-quadrant duty cycle of excavators. The report concludes by introducing other mining operations that utilize similar motion-drive systems and also static (solid-state) drives and recommends further research in these areas, as well as a more detailed examination of the dynamic fault analysis for excavators.

Jan 1, 1982

By Robert H. Merrill

Measurement of the deformation of a borehole in rock subjected to a change in applied stress can be used to calculate the magnitude and direction of the applied stress, provided a satisfactory deformation-applied stress relationship exists , In this investigation by the Bureau of Mines the deformation of a bore- hole in a rock model subjected to a known applied stress was compared with the theoretical deformation of a hole in an elastic, isotropic plate and was found to be in good agreement. Hence, this relationship can be used to calculate the applied stress on a borehole from borehole deformation measurements.

Jan 1, 1961

By H. E. Peterson, W. L. Anderson

"INTRODUCTION The great demand for tungsten incident to the war has led to the exploration of a large number of low-grade tungsten deposits. To properly evaluate the low-grade deposits it is essential to have available a dependable method of analysis applicable to all types of low-grade tungsten ores. Results reported on the tungsten content of the ores have often varied quite widely and have led to confusion. The Bureau of Mines has been requested by Government lending agencies and by companies interested in the production of tungsten to publish a general method for the determination of tungsten in low-grade ores. To meet this need, the Bureau of Mines is herein submitting two methods for analysis that have been proved on a large number of tungsten-bearing ores various types in the Bureau of Mines laboratory in Salt Lake City. Also, a third method was developed that requires no cinchonine and has proved to be applicable on most tungsten ores. The cinchonine method is the generally accepted for analysis of tungsten ores. Very reliable results can be obtained by this method if certain precautions are taken, as outlined in this report."

May 1, 1943

This appendix contains the list of equipment selected for the capitol cost estimate, with the respective quotations from their vendors/manufacturers. A vendor response report along with a separate equipment and motor list has been included in the first part of this appendix.

Jan 1, 1979

By H. Leitch

In laboratory experiments, the Bureau of Mines investigated melting, quenching, and sulfuric acid leaching of alumina from mixtures of albite and anorthite, and from anorthosites containing 26 to 32 percent alumina. Variations in pouring temperature, quenching and leaching conditions, were studied with respect to the extraction of alumina and impurities. Virtually all of the alumina was dissolved by leaching melted and quenched California anorthosite in boiling 16-percent sulfuric acid solutions for 15 to 30 minutes. The leach solutions were readily separable from the solid residue by conventional thickening and filtration techniques. Only 2 to 5 grams of SiO2, Fe2O3, or CaO dissolved per 100 grams of alumina. The quantity of SiOz in solution varied inversely with the duration of the leach and with the concentration of the H2SO4 solution used. Melted and quenched Wyoming and Minnesota anorthosites with SiO2:CaO weight ratios of 4.3 and 3.2, respectively, were less amenable to sulfuric acid leaching than California anorthosite with an SiO2:CaO weight ratio of 5.3. However, excellent results were obtained on the Wyoming and Minnesota anorthosites by the addition of SiO2 to these materials before melting, in quantities sufficient to adjust the SiO2:CaO weight ratios of the furnace charges to between 4 and 6.

Jan 1, 1966

This report presents depth and producing rate statistics pertaining to oil reservoirs (or fields) in each of the 14 States that produced more than 20 million bbl of oil during 1965. The combined oil production was about 2.6 billion bbl, or 96 pct of the U.S. total. Data are presented for each of the 14 States, each Texas Railroad Commission district, and four geographical areas of Louisiana. About 8 pct of the total oil produced in the 14 States was from depths of lees than 2,000 ft, 24 pct from 2,000 to 4,000 ft, 22 pct from 4,000 to 6,000 ft, 16 pct from 6,000 to 8,000 ft, and 30 pct from 8,000 ft and deeper. The average production per well in the 14 States ranged from 4.4 bopd for wells less than 2,000 ft deep to 57.6 bopd for wells 8,000 it and deeper. Data indicate that 9.5 pct of the 460,968 wells produced more than 1.2 billion bbl or 46.6 pct of the total oil. Oil production from reservoirs (or fields) not undergoing stimulative recovery operations, such as steam, air, gas, or water injection, wee about 1.1 billion bbl or 42.1 pct of the total.

Jan 1, 1967

By Frank L. Hess

"New England" and "granite" if not synonymous are at least associated terms. Where there are granites that are not deeply eroded there are usually pegmatites, the most erratic of rocks, and of them New England has a full portion. Many of the New England pegmatites contain the rare alkalis - lithium, rubidium, and cesium. however, the same in homogeneity of the earth's crust that has made the New England pegmatites unusual, in that so many of them contain the rare alkalis, has likewise made the distribution of the rare-alkali minerals sporadic even in those pegmatites, and most contain only enough to furnish collectors with more or less ornamental and uncommon minerals. New England has long had numberless collectors of minerals, and the mineralogists of its various schools have published many papers on the pegmatitic minerals, including those of the rare alkalis, but none of the papers have dealt with estimates of quantities. In this paper we have tried to place the emphasis on quantity rather than on mineralogy.

Jan 1, 1943