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By Charlie Wyche

Principal mineral products in the Dominion of Fiji were gold, silver, pit and quarry construction materials, and cement. In the years 1978-79, the combined total value of these commodities accounted for some $15 million,2 or 85% of the total mineral output. Production of cement, sand and gravel, and quarry products increased substantially, but gold and silver output from Fiji's only operating metal mine continued the down-ward trend of recent years. Mineral exploration by several international mining companies as well as by local prospectors was being carried out over much of Fiji, and a number of interesting prospects were discovered. One of these, a medium-size porphyry-copper prospect in the Namosi area of Viti Levu, W88 at a mining feasibility study stage. At Mount Kasi on Vanua Levu, an extensive program of geological sampling and mapping W88 being conducted, and surface sampling and drilling W88 taking place at some base metal prospects in the south-central parts of Viti Levu. Also, high gold values in surface samples were reported at Vuda in western Viti Levu.

Jan 1, 1981

By Robert W. Gordon

This report describes the results and conclusions of the further development of a lightweight probe drill for use in anthracite mines. Improvements to the drill previously developed under Contract H0282044 were made and tested at an Eastern Pennsylvania mine. These improvements were: 1. Better hole cleaning due to the development of an air-water mist flushing system. 2. The application of roof drill bits to allow drilling through rock seams and lenses. 3. The development of a quick coupling drill system which reduced total steel change time. 4. Adaptation of a swivel to the drill anchoring system which greatly reduced set-up time between holes. With these improvements the probe drill demonstrated its ability to drill the required 11 holes in one shift. It also gained miner acceptance as a viable underground working tool. The probe drill proved to meet all of the design requirements of portability, low weight drilling controllability, structural integrity and reliability. In addition to its ability to drill the required probe pattern, the probe drill has the capability of drilling long holes. By drilling several holes over 80 feet deep the probe drill has demonstrated a potential for use in robbing pillars and for methane drainage.

Jan 1, 1981

Lower workers' dust exposures during bag stacking while ergonomically improving the bag stacking process. Approach Install a new pallet loading dust control system which uses a push-pull ventilation technique along with a hydraulic lift table to control the pallet loading height throughout the entire loading cycle. How It Works A low-volume, high-velocity blower system operating at approximately at 120 cfm blows a stream of air over the top layer of bags on the pallet. The blower system is composed of two 3-inch air jets (approximately 1,200-ft/min velocity) directed toward an exhaust system on the opposite side of the pallet. As these air jets travel across the pallet, they en-train dust generated during bag stacking. The dust laden air is then captured by the exhaust ventilation system which draws approximately 2,500 cfm through an exhaust hood on the opposite side of the pallet.

Jan 1, 1989

By Charles A. Kumbe

"INTRODUCTION The Sullivan Mine was examined by Thomas L. Chapman, an engineer of the Bureau of Mines, in March 1943. Samples taken from the few mineralized exposures justified further investigation of the property. To determine whether extensive exploration of the property would be warranted, the Bureau did a small amount of trenching and underground work during April 1943, 3/ under Bureau project 1462.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its, primary objective the, more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratary project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurigical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests.The investigations of the and Metallurgical Branches of the Bureau, as reported in this paper, were supervised by J. Hedges, district engineer for Arizona, and S. R. Zimmerly, regional engineer for the Western Region, respectively."

Feb 1, 1947

By Jon I. Voltz

The U.S. Bureau of Mines has conducted fundamental coal fragmentation studies to evaluate the effects of impact energy and direction of bedding planes on dust generation, size distribution, and impact-output energy relationships. Product size distributions were obtained for the fragmented samples by screening to minus 150 mesh. The minus lS0-mesh fines were analyzed with a light scattering photometer with a measurement range of 176 to 1.9 /.tm. Increased input energy produced a significant increase in the weight of plus 3/8-in material for impact perpendicular to the bedding planes. No significant trend was observed for parallel impact. Impact direction had little influence on dust size distribution, and input versus output energy relationships. As expected, total airborne dust measured at time of impact and percent particulates below 11 /.tm in size generally increased with increased input energy for both directions of impact. Energy used for sample fragmentation increased with increased energy input.

Jan 1, 1989

By David C. McHuron

The U. S. Bureau of Mines in their continuing research into sealants, selected MBAssociates to design, build, and test equipment and evaluate sealant as to its effectiveness is shale degradation. There were 20,050 sq.ft. of coal mine roof sprayed with a mine sealant and as a result, it has been estimated that the sealant coated roof has from 50% to 95% less roof falls than that roof which was not coated with sealant.

Jan 1, 1980

By d&apos, Kathleen J. Amico

THIS SUMMARY is shown in volumes I and III of this series on mineral production in the United States (including Alaska and Hawaii), its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, and on the principal minerals imported into and exported from the United States. For further details on production, see the several commodity and area chapters. A summary table comparing world and U.S. mineral production also is included. [ ]

Jan 1, 1960

By d&apos, Kathleen J. Amico

THIS SUMMARY is shown in volumes I and III of this series on mineral production in the United States (including Alaska and Hawaii), its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, and on the principal minerals imported into and exported from the United States. For further details on production, see the several commodity and area chapters. A summary table comparing world and U.S. mineral production also is included. [ ]

Jan 1, 1960

Provide an environmentally compatible means of producing lead from galena concentrates that replaces the current high-temperature pyrometallurgical primary lead smelting process and supplies pure lead metal within present and proposed Environmental Protection Agency (FPA) and Occupational Safety and Health Administration (OSHA) lead emission standards. Approach The U.S. Bureau of Mines developed an energy efficient and pollution-free leach-electrowinning method for use in recovering pure lead metal and byproducts from lead sulfide concentrates.

Jan 1, 1989

By William J. Campbell

The Federal Bureau of Mines provided five test materials--amosite, short-and long-fiber chrysotile, crocidolite, and nonfibrous tremo1ite--to the National Institute of Environmental Health Sciences (NIEHS) for studies on the biological effects of orally ingested asbestos-related materials. An inter-agency agreement between the Bureau and NIEHS made possible this program to characterize these test materials. The Bureau in turn received support through contracts with the Ontario Research Foundation for the milling of amosite and crocidolite, and with the University of Maryland for microscopic measurements. The five test materials, which were supplied in quantities of 960 to 1,200 pounds each, were characterized by chemical-instrumental analysis for elemental composition, surface area, density, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, mineralogy, and particle size analyses. Particle size distributions were emphasized because of the current theories relating adverse biological effects to length-width characteristics of durable elongated particles.

Jan 1, 1980

By Wils L. Cooley, Herman W. Hill

'The electrical behavior of ground beds is often quite different from what would be expected based on experience with electric circuits. An explanation for this unique behavior is given, through means of an analogy, which should promote intuitive understanding of ground beds. The nonmathematical development of the text is complemented by an extensive appendix which describes the details of ground bed calculations. This work was supported by U.S. Bureau of Mines contract G0144138.

Jan 1, 1979

By K. K. Kershner

The purpose of this investigation was to develop methods on a laboratory scale for recovering tin from metallurgical slime, Tin chlorides were volatilized using mixtures of hydrogen chloride and reducing gases, such as hydrogen, carbon monoxide, hydrogen sulfide, ethane, propane, and butane. Optimum conditions were found to be n mixture of 3:1 of hydrogen and hydrogen chloride at 475° C. Over 95 percent of the tin was volatilized as chlorides. Low temperatures and relatively rapid rates of reaction are distinct advantages of the chloride volatilization process. Research is being continued with various slimes and will be extended to tin ores, where the method offers interesting economic possibilities in comparison with current tin-smelting practice.

Jan 1, 1957

By Andrew D. O. O’Brien, Linda J. McWilliams, Joe L. Howell, Douglas E. Pollock, Jeanne A. Zimmer, Andrew B. Cecala

A quick, safe, and effective method has been developed that allows workers to clean their dust laden work clothing periodically throughout the day. For the mining industry, this technique is much more effective than the current federally approved method of using a vacuuming system. This newly designed method is relatively inexpensive and can be easily installed at any operation to allow workers to clean their clothing without contaminating the worker, the work environment. or co-workers to elevated respirable dust levels. This clothes cleaning process uses an air spray manifold to blow dust from a worker's clothing in an enclosed booth, which combines the dust for capture and removal by a baghouse dust collector. Since the air exhausted by the dust collector causes the booth to be under negative pressure. no measurable quantities of dust were ever measure escaping from the booth to contaminate the work environment and/or other workers. The worker performing the cleaning process is required to wear a half-mask fit- tested respirator with an N 100 filter, hearing protection, and full seal goggles. Dust samples taken inside the respirator of test personnel performing the clothes cleaning process showed very minimal to no respirable dust. This clothes cleaning process was performed in less than 20 seconds and was significantly y cleaner than either the Federally approved method of vacuuming, or the most common method or using a single compressed air hose. It was also determined during this research that polyester-cotton blend coveralls clean more effectively than coveralls which are 100 percent cotton. The newly designed clothes cleaning process has potential application to any industry where workers' clothing becomes contaminated with most any type of dust or product.

By Jack R. Woodyard

Bonding angles, promotion energies, and relative atomic sizes can be estimated through the solution of a set of algebraic equations generated from simple atomic models, and quantum mechanical parameters such as bond strength can be estimated from simple, hydrogenic form-wave functions. The precepts of The Engel-Brewer Theory are melded with the "Crystal Approximation Model" to produce atomic-structure models making these predictions, The two-valence-electron case is presented in this report. For the candidate atoms Be, Mg, Ca, Sr, and Ba the calculated promotion energies agreed within a few percent of their experimental values. These atomic parameters determine the possible crystal structure of the candidate atoms when alloyed. This is part of the effort at the U.S. Bureau of Mines to develop methods for alloy design in response to requirements for new high-performance alloys that conserve critical or rare materials.

Jan 1, 2010

By E. L. Rawlins

A previous report4 has explained that pipe lines for the transmission of natural gas should be buried to minimize temperature fluctuations because when excessive the latter decrease accuracy in measuring gas volume and increase leakage of gas due to expansion and contraction in the pipe joints. These effects are governed by the rapidity of the temperature fluctuations and by the total variation over a period of time. The temperature of gas flowing through a pipe line depends to a large extent, upon the temperature of the ground adjacent to the pipe; hence, fluctuation of the ground temperatures at various depths determines the economic depth at which pipe lines should be buried. Scope and Purpose of Report This report covers a record of the daily atmospheric temperature fluctuations at Bartlesville, Okla., for 12 months and a-similar concurrent record of the temperature variation 1, 2, 3, and 4 feet below the surface of the ground.

Jan 1, 1928

By J. G. Stuart, A. W. Cipkins, R. H. Thompson

Preliminary safe distances for blasting wiring from typical electromagnetic sources are presented. The distances are for underground coal mines and electromagnetic sources in the frequency range below 10 MHz. The distances are based on measurements performed at 3 locations in each of 3 coal mines. The measurement apparatus, measurement procedure, measurement results and the rationale used in the calculation of the safe distances are all described. The safe distances presented are dependent on the measurement results and their interpretation. More measurements are clearly necessary to establish the validity of the suggested distances.

Jan 1, 1985

By Gwendolyn D. Hood

The U.S. Bureau of Mines developed a dewatering technique for treating wastewater that was tested on waste slurry from a commercial tile company in Alabama. Raw wastewater samples were pretreated with 10 Ib calcium chloride and 10 lb Wyoming bentonite per 1,000 gal of slurry. After pretreatment, polyethylene oxide (PEO) at dosages varying from 0.05 to 0.20 lb per 1,000 gal was mixed with the waste slurry, forming strong, tough floes that were separated from the clarified water using a trammel. The flocculated slurry was dewatered to a consistency that could be handled for subsequent disposal in a landfill. The clarified water quality was equivalent to that of the company's present treatment system.

Jan 1, 2010

By W. H. Lewis

This Bureau of Mines report and its companion report (Information Circular 9073) have been prepared as a complete reference on underground coal mine lighting. This report discusses system design criteria and procedures, data and specifications to aid in selection of suitable mine lighting hardware, and guidelines for system installation and maintenance. Topics include light measuring techniques and instruments, illumination regulations for underground coal mine environments and equipment, lamps and ballasts, available mine lighting hardware, design and evaluation of coal mine illumination systems, and installation and maintenance of a mine lighting system.

Jan 1, 1986

By D. L. Sawyer

Aqueous C12-02 leaching procedures developed by the Bureau of Mines to produce zinc chloride from zinc sulfide bulk concentrates were effective in extracting 99 pct of the zinc and 97 pet of the silver contained in samples of massive seafloor sulfides from the southern Juan de Fuca Ridge. Zinc sulfide (sphalerite and wurtzite) mineralization comprised 55 and 88 pct of two specimens provided by the U.S. Geological Survey for this study. Minor occurrences of galena, chalcopyrite, and other minerals in the sulfides permitted the recovery of pregnant liquors that were low in metal values other than zinc, which were successfully purified by a two-step cementation procedure using zinc dust.

Jan 1, 1983

By J. M. Singer

The objective of this investigation was to determine minimum air velocities and entrainment rates for coal and rock dust dispersion in wind tunnel experiments under conditions that simulate dispersion from surfaces in coal mines where airflows are induced by weak gas explosions. Dust deposits were bed-or ridge-shaped; particle sizes were 6 to 80 microns (cohesive deposits) or 100 to 150 microns (free-flowing deposits); and wind tunnels were 7.62 cm wide by 5.08 cm high by 300 cm long, and 2.4 m wide by 1.5 m high by 215 m long. The investigation showed that minimum air velocities (directed at mid-height) of separate, layered, or mixed piles of coal dust and rock dust were within the range 5 to 30 m/sec, independent of size of wind tunnel. This finding considerably facilitates scaling of data to mine-size passageways. Free-flowing deposits dispersed relatively slowly by single-particle detachment; cohesive dusts dispersed faster by the breaking and lifting of large clumps along weak failure flames; particle dispersion occurred in flight. Layered or mixed deposits of coal and rock dust did not disperse selectively. Semiempirical expressions were derived relating minimum air velocities and dispersion rates to dust-pile geometry, cohesion, porosity, and bulk density.

Jan 1, 1972