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By J. P. McGee

The Bureau of Mines is doing research and development work on a coal-fired gas turbine plant initially developed by the Locomotive Development Committee, (LDC) of Bituminous Coal Research, Inc. The Bureau is redesigning the turbine blading and some of the auxiliary equipment, and is reerecting, the plant at the Morgantown (W. Va.) Coal Research Center. The present goal is a 1,500-hour run at virtually the same operating conditions used by the LDC in their final 1,100-hour test with the turbine. This will allow the Bureau to properly evaluate the new blade design. Erosion of the turbine blades (particularly the roots) by ash in the hot gases from the combustion of coal was the most serious problem in extended operation in earlier experimental work. New blades made of Stellite6 are being fabricated for the stator and rotor, and armored wear strips of titanium carbide will be inserted in the blades at the areas of probable maximum ash velocity and concentration. The trailing edges of the rotor and stator blades are being thickened and thinned, respectively, to induce the ash to travel to the casing and prevent it from returning to the base of the rotor blades. The first stage rotor and second stage stator blades are being removed to provide an annular space for maximum quantities of coal ash to centrifuge to the casing. Additional blades will be added to most of the rows in the stator to stop secondary flow of dust-laden gas toward the rotor. A contract has been awarded for fabrication of the new blades. The 1,500-hour run will be started as soon as the new blades are installed.

Jan 1, 1962

By William L. Crentz

In a Nation-wide appraisal of coking-coal reserves and of the practicability of upgrading marginal deposits to metallurgical standards, this study of the preparation characteristics of the coals in Cambria County, Pa. , was undertaken. Over 90 percent of the coal remaining in Cambria Comity is found in the Upper Freeport, Lower Freeport, Upper Kittanning, and Lower Kittanning beds. The Middle Kittanning bed, although mined on a commercial scale in the past, is not an important bed now, as most of the remaining reserves are too thin to be mined over wide areas. For many years, Cambria County has been an important source of coal for industrial and metallurgical purposes. The) principal production comes from the Lower Kittanning bed, which accounts for almost .60 percent of the Cambria County coal output. Table 1 shows the county's coal production, by beds, during 1948.

Jan 1, 1950

By Ross. C. Barkley

A computer program has been written to simulate ground vibrations induced by multiple-hole surface blasts. The program is an inexpensive and relatively easy to use tool for predicting the principal blast vibration characteristics that determine damage and annoyance potential: peak particle velocity, frequency content and pulse duration. The program generates a complete ground motion history by superposing, at any surface position, the vibrations induced by each individual explosives charge. It requires specification of (hence allows accounting for) the blast geometry, initiation sequence (including random delays), position with respect to blast, pulse characteristics induced by each charge, and propagation laws. A methodology is outlined to determine the necessary variables either on the basis of site investigations (e.g. velocity, attenuation, pulse), or by backcalculation from measured blast vibration records. The latter procedure has been applied to blasts from two coal strip mines. Main difficulties are backcalculating individual pulses, propagation (especially dispersion) parameters and delays. A normal distribution of delays, based on published results, has been shown to influence the results and the response of a single degree of freedom structure significantly. Broadening of the wave types included and additional verifications with field results are required.

Jan 1, 1983

By W. T. Wertman

A research program to aid development of better petroleum-recovery technology is in progress at the Appalachian Experiment Station, Bureau of Mines, Morgantown, W. Va. The work is part of the overall effort of the Federal Bureau of Mines to effect true conservation of the Nation's natural resources. Knowledge of the magnitude of the interstitial water content of oil-bearing formations is important to petroleum-reservoir engineers because of the influence of water on fluid flow during oil production and because of the significance of water volume in oil-reserve evaluation. Such information on Appalachian oil-bearing formations is needed to aid in planning secondary oil-recovery projects. Generally, the interstitial water content of oil sands can be estimated by one or more of the following methods: Analysis of cores obtained with oil-base drilling fluid, electric logging, restored-state or capillary-pressure tests, centrifuge tests, evaporation tests, or mercury-injection tests.

Jan 1, 1959

By D. Harrington

Educational campaigns conducted by the manufacturers of explosives, the Bureau of Mines, mining companies, and safety organizations have contributed greatly in reducing accidents caused by explosives arid blasting. Despite these campaigns and the dissemination of information, accidents from explosives and blasting continue to be the direct cause of scores of fatalities and hundreds of nonfatal accidents annually, not only in the mineral industry but essentially wherever explosives are used. The experience of many mining companies and other users of explosives has proved that accidents from explosives can be prevented or averted by the proper training of employees in the handling and using of explosives and by the enforcement of definite rules and instructions for their use. Unfortunately, throughout the years numerous false impressions and ideas have grown up and around the use of explosives. Many of these can be traced back to the manner in which the users of explosives were originally taught, if instructed at all; and as with many types of misinformation in nearly all walks of life, those false ideas are decidedly persistent and being so cause much damage. Many if not most of the users of explosives gained their knowledge of explosives and blasting by watching others and more or less "absorbing" the procedures and thrones of the other fellow, who acted unconsciously as teacher or instructor. A study of explosives accidents reveals the results of such "teachings" when the causes of the accidents are determined, and as might be expected the results very often are far from good. One of the most persistently erroneous impressions or ideas is concerned with the burning rate of safety fuse. Many men with

Jan 1, 1944

By Ronald M. Hays

The Duluth Gabbro Complex in Northeastern Minnesota possibly contains a significant domestic copper resource and the nation's largest nickel resource. Exploration has discovered large low-grade copper-nickel (Cu-Ni) deposits between Hoyt Lakes and the Boundary Waters Canoe Area (BWCA). The mining and processing of Cu-Ni will have environmental, economic, and social impacts. The purpose of this study is to relate major environmental, economic, and social considerations to various aspects of Cu-Ni extraction. An open pit and two underground (block caving and open stoping with backfilling) models were developed to generate information on the impact of Cu-Ni extraction. Important considerations having environmental, economic, and social impacts (luring various aspects of Cu-Ni extraction are identified and defined. These aspects are exploration, development, mining, beneficiating, smelting, transportation, and termination of operations. Considerations are grouped into the general categories of site, industrial, energy, climatic, resource, water, air emission, waste disposal, employee, tax and royalty, transportation, and community considerations. Cu-Ni extraction in Northeastern Minnesota presents major environmental, economic, and social risks. Decisions are required on trade-offs between adverse and beneficial impacts. The approach used in this study assists in assessing environmental, economic, and social impacts. It will aid in the examination of potential and projected short-term and long-term advantages and disadvantages and will aid in the development of Minnesota's Cu-Ni resource for the maximum benefit to society.

Jan 1, 1974

By Laurence G. Trudell

Geology and oil-yield data are presented for a 58-square-mile area encompassing the U.S. Department of the Interior oil-shale leasing program tracts in the western Washakie Basin, Sweetwater County, Wyo. Lithology and oil yields of samples from three Bureau of Mines coreholes are evaluated and correlated with Kinney Rim surface sections measured and sampled by the U.S. Geological Survey. Minable sections of oil shale averaging up to 25 gallons of oil per ton crop out on Kinney Rim in the Laney Member of the Green River Formation. Thick oil-shale sections in the Laney Member that average 15 gallons per ton represent 155 million barrels of oil in place per square mile. In the lower part of the Green River Formation the Tipton Shale Member contains a 20-to 40-foot section averaging 15 gallons per ton. Beds of high-volatile C bituminous coal up to 6 feet thick are present in intertongued parts of the lower Green River Formation and upper Wasatch Formation.

Jan 1, 1973

By Robert Stefanko

The following tables contain the average, maximum and minimum power parameter levels for several mining machines. Power factor is listed only for defined transducer output regions. The reasons for the undefined areas are provided in the Instrumentation Chapter. Several maximum voltage drops are included, and are computed from the no load line-to-line voltage: Again, the drops are from measurements at the low side of the load center. The machines are: Continuous Miners; F6A Alpine 76AM Jeffrey (d-c) 8CM Joy 8CM (10CM) Joy 9CM-2AH Joy loam Joy CU-43-2H Joy 2 each CM26H Lee-Norse CM28E Lee-Norse Shuttle Cars; 18SC Joy 48S Torkar (a-c) 2 - 10SC Joys input to rectifier 2 - 16SC Joys input to rectifier

Jan 1, 1973

Effective control of respirable dust is one of the most serious problems associated with longwall mining in the United States. This report describes the development and laboratory testing of dust collectors for use on double drum shearers. Systems tested included: ? High Capacity Flooded Bed Scrubber ? Water Powered Extraction Cowls ? Water Powered Extraction Drums ? Water Powered spot Scrubbers. The systems were tested using tracer gas in a full-scale model of a longwall shearer face. This report provides a detailed description of the test facility, test methods, and system test results.

Jan 1, 1982

By Frank M. Vodoklys

This is the final report on Contract H0220049 covering the period from 27 April 1972 to 30 April 1974. The objective of the contract was to develop and evaluate materials and methods to achieve post explosion identification of explosives reliably and economically through the use of phosphor coded grains incorporated into the explosive during its manufacture. A coding system of two spotting phosphors and seven coding phosphors was successfully developed during the execution of the contract. The ability of the coded grains to survive detonation in many different types of explosives was demonstrated and the complete code was extracted from a single 100 micron post-explosion fragment. A method was established for testing grain strength to correlate with field test results and an optical system was designed for extracting the code from the grains. Also in fulfillment of the contract requirements a laboratory method for manufacturing the coded grains was established and ten one-pound samples, each with a different code, were fabricated. Finally, a method was developed for applying a coating of polyethylene to the grains to prevent sensitization of the tagged explosives and the ten one-pound samples were coated and delivered to the Bureau of Mines.

Jan 1, 1974

By W. R. Byrnes

This project was initiated on October 1, 1980 and will be completed on December 31, 1983. The project was Initially approved and funded by the Office of Surface Mining and subsequently was moved to the jurisdiction of the Bureau of Mines. It was administered through the Indiana Mining and Mineral Resources Research Institute. The research was done to assess reforestation success and ultimate productivity for areas reclaimed under the Surface Mining Control and Reclamation Act of 1977 (P.L. 95-87). The Permanent Regulatory Program for implementation of P.L. 95-87 Includes provisions for revegetation that require seeding of ground cover plants to control erosion until permanent vegetation such as tree species Is established, and restoration of mined land to its original or better productivity. Much of the land to be surface-mined presently supports forest cover and it is anticipated that reconstructed minesoils will exhibit high productive potential for hardwood tree species. Hence, information was needed on compatibility of ground cover and tree seedlings when established concurrently as well as on revegetation success under postmining versus premining conditions.

Jan 1, 1983

By James L. Ash

This report contains the results of a technical and economic evaluation of conceptual systems for the underground mining, rubblization, and in situ retorting of deep oil shale deposits. Study efforts were first directed towards evaluation of the applicable geology, associated minerals, rock mechanics, in situ retorting, access mining, ventilation, rubblization, safety, and environmental impact factors. Conceptual systems were synthesized and then evaluated against these factors from both a technical and limited economic viewpoint. The results of these evaluations were then analyzed and, based upon this analysis, the following two systems were selected for further study: System II: Room and Pillar-Vertical Drill and Blast System IV: Tunnel Boring-Horizontal Ring Drill and Blast Due to the large number of variables to be considered, a computer program was developed and utilized to provide data for the cost trade-off studies and economic analysis. Results of the early computer runs indicated the value of the tool available? in the computer program and led to an extension in the contract to determine the sensitivity of the systems to several of the more apparent significant variables. These results in turn led to a refinement in the design assumptions and a better understanding of the technical and economic options available to an owner-operator of a Vertical Modified In Situ Shale Oil Extraction System. This report is submitted in fulfillment of the requirements of Contract Number 50241073 by Fenix & Scisson, Inc. to the Denver Mining Research Center, United States Department of the Interior, Bureau of Mines. Work was completed as of November, 1976.

Jan 1, 1976

As a result of early experiments in underground mine illumination, the Bureau of Hines recognized the need for additional experience with the underground lighting of coal mines having low seam thicknesses. There was already experience with tile illumination of coal mines having higher coal seams, and this contract with Ocean Energy Inc. (OEI) was undertaken to contribute to the "low coal" experience. For the purpose of this contract, a "low coal? mine is defined as one having less than 45 inches of overall headroom in the working places. As a practical limit, 26 inches was the minimum coal seam thickness to be encountered in this program. In one instance, the maximum coal seam thickness was eight to ten feet, however, this particular work was at the direction of the Technical Project Officer (TPO) by virtue of the unique type of lighting arrangement that was to be evaluated which would be useful for low coal. At the outset of the contract, three major tasks were established. The first two tasks involved the installation of permissible fluorescent lighting equipment at two low coal mines. The intention was to illuminate mining sections in each case consisting of one or more machines. The third task was to illuminate a variety or mining equipment including a longwall. For the purpose of this report, the fol-owing identifies the particular installations associated with each task.

Jan 1, 1976

By G. S. Beaumont

This report presents a programme of work to demonstrate the use of a surface-based centralised computer control system for the remote monitoring and control of underground conveyors in a US coal mine. The system selected for demonstration was the 'Dynalink' Micro MINOS system which is manufactured by Hawker Siddeley Dynamics Engineering Limited. The site selected was Barnes S Tucker Lancashire No. 20 Mine located near Carrolltown, Cambria County, Pennsylvania. The system concept, operating and application software was designed and developed by the. British National Coal Board. The report describes the selection of the site, specification of the system requirements, commissioning, operation and evaluation of the system under typical US mine operating conditions. Experience with the system, based primarily on the system reliability and performance of conveyor control, was favourable. Mine management personnel felt that the system had successfully achieved its objectives and were keen to expand monitoring and control to other activities.

Jan 1, 1986

By Joseph A. Conway

This paper is one of a series dealing with the mining and crushing methods and costs of the nonmetallic industries, prepared under the sponsorship of and in cooperation with the U. S. Bureau of Mines,. The quarrying methods described in this paper are those used at the Monocacy trap rock quarry which annually produces from 450,000 to 500,000 tons of crushed stone. This property is located 3 miles east of Birdsboro at Monacacy, Pa., and is one of the three quarries operated by the John T. Dyer Quarry Co. Throughout the paper an effort is made to explain the various methods used and the cost of operation.

Jan 1, 1931

By William H. Pomroy

The Bureau of Mines, through a 4-year program of combined in-house and contract research, has developed the necessary hardware and software technology to provide rugged, reliable automatic fire protection for surface mining mobile equipment. One element of this program was a continuing effort to help foster rapid mining industry acceptance of the technology by keeping end user costs reasonable. This report is an analysis of the economic impact of surface mining mobile equipment fires and the cost benefit of utilizing automatic fire protection systems to abate these losses.

Jan 1, 1982

By Eric E. Cather

A mineral survey of the Fisher Gulch RARE II area (A5299), Trinity County, California was conducted by the U.S. Bureau of Mines and U.S. Geological Survey. The Bureau of Mines was responsible for detailed examination of mines, prospects, and mineralized zones; the Geological Survey conducted geological, geochemical, and geophysical studies of the area. The area is underlain by the Salmon Hornblende Schist. Tonalite stocks 1.5 mi (2.8 km) to the east and northeast of the area intrude the schist and are closely associated with the nearby nines (Cox, 1967). The mines have quartz veins containing sulfides and gold in shears trending east to north past in the schist and tonalite (Hotz, 1972). Strewn and terrace gravel s occupy most of the drainages, many have yielded substantial quantities of gold.

Jan 1, 1981

By James M. Spear

Sample results suggest the only mineral resources in the study areas are placer gold deposits along the South Fork Kern River in the Woodpecker RARE II unit (fig. 1). These deposits, in Rockhouse Basin, total 4.5 Figure 1.--NEAR HERE. million cu yds (3.4 million cu m) of indicated subeconomic gold resources in four deposits of "older" gravel. Gold value in samples averages $0.36 per cu yd ($0.47 par cu m) and is as much as $4.44 per cu yd 1/. Cost of mining the gravel and recovering the placer gold is estimated to be more than $2 per cu yd ($2.62 per cu m) for a deposit of this size and type. Additional inferred subeconomic placer gold resources with similar grade probably occur in four other deposits of "older" gravel on which no mining claims were located. Placer gold occurrences on upper Trout Creek contain gold worth as much as $4.50 per cu yd ($5.88 per cu m) 1/. Average grade is much lower, and only about 1,000 cu yds remain (760 cu m). These occurrences do not constitute a resource, but may attract hobbyists not dependent upon making a profit.

Jan 1, 1982

By N. S. Dalal, A. H. Hoffman, X. Shi, D. E. Banks, J. K. H. Ma, Y. Rojanasakul

Excessive production of reactive oxygen radicals by alveolar macrophages is proposed to play an important role in oxidative lung injury. A major product of oxygen radical formation is the highly reactive hydroxyl radical (•OH) generated via a biologic Fenton reaction. In addition to its known ability to induce lipid peroxidation, recent studies have suggested that the •OH may exert its cytotoxic effect through the alteration of [Ca2+], homeostasis. To test this potential mechanism as well as to investigate the relationship between •OH and Ca" overloading in cytotoxic injury, isolated rat alveolar macrophages were exposed to externally generated radical system, H2O2 (0.01 to 1 mM) and Fe (1 mM) and their [Ca2+] levels and cell injury were monitored using quantitative fluorescence microscopy with the aid of the specific Ca" indicator, Fura-2, and membrane integrity indicator, propidium iodide. Electron spin resonance measurements using the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) confirmed the production of the .OH radical by this system. Upon the addition of the radicals, the macrophages displayed a rapid initial rise in [Ca2+] which was followed by a slower but more pronounced [Ca2+], elevation that reached a level 3 to 5 times higher than the basal level. This process preceded cell death as evident by nuclear propidium iodide fluorescence. Depletion of extracellular Ca" inhibited both the [Ca2+], response and cell injury. Preincubation of the cells with the Ca" channel blocker verapamil or .0H radical scavenger mannitol similarly inhibited the [Ca2+], rise and loss of viability. Firefly luciferase assay of cellular ATP content demonstrated that the alterations in [Ca2+], following .0H treatment preceded the depletion of ATP. Changes in membrane potential caused by Na* substitution with K* had no significant effect on either the unstimulated or stimulated [Ca"], levels. Taken together, these measurements indicate that .OH-induced injury in alveolar macrophages is associated with the alteration in [Ca2+], homeostasis. The mechanism of •OH-induced [Ca2+] loading is not due to nonspecific membrane damage or energy depletion, but mainly due to an increase in Ca2+ influx through Ca2+ selective channels. This Ca2+ over-load state as well as energy depletion caused by the oxidant may activate certain cellular degradative processes leading to cell injury and death.

Nov 1, 1995

By Marcel Vanpee

Eight extinguishing powders KCI, were tested on five types of diffusion flames. The effect of flame temperature on the inhibition efficiency was investigated by varying the oxygen index of the flame supporting atmosphere. Inn addition a spectrographic investigation of powder flame dissociation products was carried out on the methane/air/ABC (NH4H2PO4) flame. Dissociation products for this flame included P0, PH, NH, and Na. It is concluded that the main factor to be considered in the efficiency of tie powder is the flame temperature Purple K (KHC03) was typically inefficient in low temperature flames and very efficient in high temperature flames. On the other hand, ABC (NH4H2PO4) was found to lose its efficiency at high temperature but to be quite efficient in the low temperature flames. The effect of temperature is offered as an explanation of the poor efficiency of Purple K (KHC03), against coal dust explosions as contrasted to the high efficiency of phosphate salts against coal dust explosions.

Jan 1, 1982