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By R. Van A. Mills

[In previous contributions** the writer has called attention to important relations that faulting bears to the migration and accumulation of oil end gas. It has been pointed that favorably situated parts of oil and gas bearing, sands have been enriched by migration art segregation incident to faulting. The escape of water through natural passages such. as fault fissures has induced wide spread hydraulic currents through the beds toward these, points, of diminished pressure and these water currents, plus buoyancy hove contributed largely toward the migration of oil to favorable rock entrapments in the vicinity of the faults.*** The propulsive force of expanding gas has been one of the contributing causes for the hydraulic currents. Paradoxical as it may seem, the escape of gas with entrained oil through fissures has been on important factor In the migration, and accumulation of oil in many faulted areas. Compressed gas is the propulsive force by which oil generally moves to producing wells. It is also one of the propulsive forces by which oil has moved with or even ahead of water under conditions: of differential pressure brought about by faulting.]

Jan 1, 1922

This chapter summarizes data on crude mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Included also are tables that show the principal mineral commodities exported from and imported into the United States and that compare world and U.S. mineral production. The detailed data from which these tables were derived are contained in the individual commodity chapters of volume I and in the State chapters of volume n of this edition of the Minerals Yearbook. Although crude mineral production may be measured at any of several stages of extraction and processing, the stage of measurement used in this chapter is what is normally termed "mine output!' It usually refers to minerals or ores in the form in which they are first extracted from the ground, but customarily includes the production of auxiliary processing at or near the mines.

Jan 1, 1979

By Donald M. Hausen

Diamond-bit performance and cost data accumulated by the Bureau of Mines in core-drilling schists reveal significant trends of economic interest. Low-quality, small-size drill bort were the most economical. The percentage of core recovery, type and size of bit, and bit matrix are also correlated with bit performance and costs. Detailed analyses of the factors affecting diamond-bit performances and costs are assessed in the tables, graphs, and discussion.

Jan 1, 1956

By F. N. Kissell, R. J. Bielicki

The Bureau of Mines found sulfur hexafluoride (SF6), released from a lecture bottle, to be an ideal gaseous tracer for studying mine ventilation systems. Air samples were collected in glass syringes and analyzed by electron-capture gas chromatography. In these studies, the lower limit of detection was about 1 part per billion by volume (ppb) of SF6 per part of air. Experiments conducted in a Pennsylvania limestone mine showed this technique useful in evaluating the effectiveness of auxiliary fans, measuring low flow velocities, probing the air circulating near a working face region where ventilation appeared to be poor, and estimating volumetric flow rates in airways of large cross-sectional area and having low flow velocities. This technique was also used in a western vein-type metal mine to measure the amount of return air being recirculated into the intake air due to leakage through old stoped areas.

Jan 1, 1974

Develop a method for recovering phosphate from a wide variety of complex western phosphate materials, including low-grade ores, tailings, and unused fines. Approach A flotation technique is used for this broad type of extraction. The method includes depression of phosphate minerals and anionic flotation of carbonate minerals, followed by cationic flotation of silicate minerals. How It Works A slurry is prepared for flotation by sizing to remove a low-grade, high-impurity slime fraction. Depending on the material, further sizing and/or grinding steps may be used to produce a size concentrate or to remove gangue. The flotation feed is conditioned with H2SiF6 and a fatty acid emulsion. The H2SiF6 is absorbed chemically to the phosphate mineral surface, making it strongly attracted to water and preventing adsorption of the fatty acid. Under these conditions, the fatty acid is a selective collector for carbonate minerals, which are removed as a froth product. Next, the silicates are floated with an amine reagent added directly to the slurry without additional pulp preparation.

Jan 1, 1982

Detect hazards associated with abandoned mine openings through the use of integrated geophysical technology. Background Many abandoned mines in the U.S. present hazards to the public. The first step in abatement of these hazards usually requires locating the abandoned workings. Recent Colorado legislation resulted in a concerted effort aimed at mitigating the hazards associated with abandoned mine workings. The Colorado Department of Natural Resources-Mine Land Reclamation Division (CDNRMLRD) is responsible for locating and backfilling abandoned mine openings such as shafts, adits and collapsed features. Many shafts and adits can be located by inspection, other openings give little or no surface expression and must be located by drilling, or through the use of geophysical methods. A common method used for locating underground mine workings is to drill throughout the suspected area. However, it is prohibitively expensive to drill holes at the spacing needed to detect backlilled shafts and small voids associated with caving and/or chimneying. It may also be dangerous to move heavy equipment over shallow mined-out workings. Geophysical investigations that employ only a single method have had mixed success in detecting hazardous abandoned mine land cavities.

Jan 1, 1991

By S. J. Hussey

A jig tailing with gold content ranging from 0.33 to 0.43 oz/ton was leached in weak cyanide solution with extractions of up to 97 pct in 24 hours. By countercurrent batch leaching studies and laboratory pilot plant operation, minus 10- plus 20-mesh and minus 6- plus 16-mesh coconut carbon were loaded to 700 oz/ton of Au. Minor silver in the ore reported in the carbon in amounts of up to 100 oz/ton. Gold adsorption rate data and an equilibrium adsorption curve for minus 10- plus 20-mesh carbon at ambient temperatures were developed and used in the successful application of a cascade design theory. The work was performed as a part of the overall Bureau of Mines research effort to help maintain an adequate domestic supply of metals by making improvements in mineral-processing technology.

Jan 1, 1979

By Stephen C. Tadolini, Thomas M. Barczak

Western mines have had limited choices for standing support. Wood cribs were often too soft and unstable. The introduction of the Can support in the early 1990’s provided a very effective alternative and remains the dominant form of tailgate support. Water-filled prestressing cells are now used to cap the Can and preload it to provide an active roof load. The Cluster Prop, consisting of three timber wedge props bundled together, provides more capacity than an equivalent sized Can support and improves transport efficiency. However, the Cluster Prop is less stable and does not maintain a consistent load throughout its loading profile. Pumpable roof supports are another alternative support, but they have not been proven in high deformation environments. Alternative supports are also being used in longwall recovery operations. These include the Rocprop and Omni Prop, which are extendable support systems. They also provide active roof loading which can be beneficial in these applications. Specialty supports, such as the Sand Prop and Spider Prop, have also been introduced into western longwall operations. This paper compares the performance characteristics of these various support systems.

By A. Visnapuu

The Bureau of Mines investigated carbonyl processing techniques for the recovery of the critical metals Ni, Co, Mn, and Cr from domestic primary and secondary sources. In most cases, the source materials require reductive precarbonylation treatment to metallize the contained Fe, Ni, and Co compounds to render them reactive with CO. The critical metals were recovered either by direct conversion to the respective carbonyls or as upgraded products by carbonyl removal of an undesirable metal. Best metal-to-metal carbonyl conversion was under CO pressure, from 80 atm upward, and at 1400 C. Carbonylation was accelerated by the addition of HzS in small quantities. CO pressure, temperature, promoter and pretreatment trends, and other factors enhancing metal carbonyl formation are presented.

Jan 1, 1987

By D. R. Douslin

This report describes an inclined-piston pressure gage that operates from a zero-pressure datum level. The gage is adaptable to accurate vapor-pressure measurements in the low and intermediate pressure range, 0.01 to 40 mm (mercury). Residual friction in the oil-lubricated piston-cylinder combination is eliminated by a unique oscillatory method that is free of end thrust on the piston and allows the full sensitivity of the gage to be realized. The axial component of the weight-to-area ratio of the piston is determined by measuring the angle of inclination with a goniometer that can be read to 1 sec. Accuracy of the gage proper is estimated to range from 0.001 to 0.012 mm from lower to upper pressure limits. Its highest practical sensitivity is about 0.0005 mm. As a test, the vapor pressures of ice and water were measured in the range -30° to +20° C.

Jan 1, 1963

By Stephen D. Smith

This chapter summarizes data on crude nonfuel mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Also included are tables that show the principal nonfuel mineral commodities exported from and imported into the United States and that compare world and U.S. mineral production. The detailed data from which these tables were derived are contained in the individual commodity chapters of Volume I and in the State chapters of Volume II of this edition of the Minerals Yearbook. Although crude mineral production may he measured at any of several stages of extraction and processing, the stage of measurement used in this chapter is what is normally termed "mine output." It usually refers to minerals or ores in the form in which they are first extracted from the ground, but customarily includes the output from auxiliary processing at or near the mines.

Jan 1, 1989

By F. Chase, D. Pappas

Pillar recovery has been associated with nearly one third of roof fall fatalities in underground coal mines during the past decade. Safe pillar recovery requires global stability and local stability. Global stability is addressed primarily through pillar design. The local stability risk factors include cut sequence, the final pillar stump, supplemental supports (timbers vs. Mobile Roof Supports (MRS)), roof bolting, and many others. The National Institute for Occupational Safety and Health (NIOSH) has evaluated each of these factors through field research and analysis of accident statistics. The paper discusses design methods and technologies that have been transferred to the mining community and implemented.

By Thomas A. Gray, Lynn M. Crayne, Michael A. Trevits, Phil Glogowski

Mine seals can be remotely constructed in underground coal mines, through vertical boreholes, when direct access to a fire is impossible or considered to be too dangerous. This method has great merit because boreholes can be drilled to specific mine areas and seals can be positioned close to a fire zone. The technology however, can be largely ineffective if the constructed seals do not provide effective barriers to airflow or cannot be used to impound water and other inert materials. Unfortunately, no viable alternatives exist to sealing the entire mine at the ground surface. Full-scale remote mine seal construction research is being conducted at the National Institute for Occupational Safety and Health’s (NIOSH) Lake Lynn Laboratory (LLL). Under this effort, Howard Concrete Pumping Company and GAI Consultants, Inc. have joined forces to evaluate a potentially significant improvement to the current state-of-the-art. This paper will cover development of novel technology for remote mine seal construction, evaluation of the materials used, construction practice, and follow-up testing.

By W. L. Hunter

Eleven steelmaking heats are described in this Bureau of Mines report in which acid practice was used to produce carbon steel from pre reduced iron ore pellets. Furnace slags obtained with no flux addition to the charge became quite viscous as they cooled, which precluded pressure casting from a ladle. Lime was added to the furnace charge at two levels to eight of the heats to modify slag characteristics in the furnace, and to the ladle in two heats to further modify the ladle slag cover. Selected ingots from nine heats were successfully rolled on a commercial mill to produce No. 10 reinforcing bar.

Jan 1, 1974

Improve the safety, reliability and overall effectiveness of mine stench warning systems and to provide a means of remote control stench injector operation. Approach Industrial gas odorants were analyzed for their suitability for use in mine stench warning systems. A prototype stench injector capable of precise flowrate control was designed, fabricated, and tested using the odorant chosen as having the most favorable properties. Based on the results of the field tests, a second generation injector was developed. The second generation unit features optional remote control operation, and in addition, is simpler to refill and is less expensive than the original injector. A complete second generation system, consisting of two manually operated injectors and one remote controlled injector was in-mine tested through actual mine fire drills. How It Works Ethyl mercaptan mixed with Freon is the predominant stench agent used in the U.S. underground metal and nonmetal mines. However ethyl mercaptan's toxicity,

Jan 1, 1982

By Howard E. Parkinson

The mine pager phone to public telephone interconnect system permits mine paging telephones to be interconnected with the public phone system, thereby providing emergency and off-hours communications. The system, a push-to-talk, push-to-listen system, is compatible with any mine paging system utilizing dc voltage on the line to enable paging. A tone generator of the proper frequency enables an outside caller to page over mine pager system loudspeakers. A caller inside the mine can make an outgoing call to a preselected, preprogramed number with the use of a proper frequency tone generator. The system includes an automatic hangup timer that restricts the time off-line due to a wrong number or incorrect hangup to 20 seconds and 6 minutes, respectively.

Jan 1, 1974

By T. O. Llewellyn

The Bureau of Mines conducted laboratory batch beneficiation tests on a waste granite sludge from New Hampshire to determine the feasibility of recovering a reusable silicon carbide product. The granite sludge responded to attrition scrubbing, desliming, and flotation in either alkaline or acid circuits using fatty acid as a collector. Recovery of over 80 percent of the contained silicon carbide at grades of up to 96 percent SiC was obtained.

Jan 1, 1975

By Ann G. Kim

Methane in coal constitutes a serious hazard during mining. Draining the methane from large blocks of coal in advance of mining is an effective method of improving the safety and efficiency of coal mining. Because of the similarity of the two gases, drained methane can be recovered and added to pipeline supplies of natural gas. To effectively apply advance drainage techniques and recover drained gas, a gross estimate of the methane content of coal is necessary. Using data from previous investigations, the virgin reserves of the Pittsburgh coal in the central and southwestern parts of Washington County, Pa., are estimated at over 1.5 billion tons, with a methane content of 50 to 100 fts/ton. The Pittsburgh bed in this area of approximately 265 mi2 contains over 130 billion ft3 of methane.

Jan 1, 1974

By Clete R. Stephan, Mark J. Schultz, William A. Slivensky, Eric S. Weiss, Kenneth W. Jackson

he Pittsburgh Research Center (PRC)~ and the Mine Safety and Health Administration (MSHA) are participating in a research program to evaluate the strength characteristics and air leakage resistance of seals and water trap designs for use in underground coal mines. This program is being conducted at PRC's Lake Lynn Laboratory near Fairchance, Fayette County, PA. Seals designed with a 40-cm-thick polymer (polyurethane) and aggregate core between two dry-stacked (no mortar) concrete block walls (coated on out by sides) withstood a 138-kPa pressure pulse while maintaining acceptable air leakage rates. Similar seal designs utilizing a 97-cm-thick, 91-kg/m7-density, polymer-only core did not survive; however, a 5 1 -cm-thick, 203-kg/mi-density, polymer-only core seal successfully withstood the explosion pressures. Evaluations of cellular concrete seal designs have shown that a two-pour slurry injection technique did not adversely affect the strength of the 1.2-m-thick seals when subjected to a 138-kPa pressure pulse. Two seal designs utilizing low-density cementitious block have also been evaluated with successful results. In addition to seal strength tests, various 15- and 30-cm-diam U-shaped water trap pipes and a water trough design were evaluated under explosion conditions and were shown to be inadequate when evaluated under worst-case conditions. Simple modifications to the various water trap designs were successfu1 in preventing the passage of explosion flame through the trap.

Jan 4, 1996

By Ted C. Briggs

Equations for the elastic pressure distortion of the volumes of a Burnett compressibility apparatus are developed and presented in this report for volumes under internal and external applied pressures. An experimental method for the determination of the external pressure distortion coefficients is presented. Young?s modulus and the internal-pressure distortion coefficients are computed from the experimentally determined external-pressure distortion coefficients. The temperature dependence of the pressure distortion coefficients and of Young's modulus is evaluated for the temperature range 0° to 80° C.

Jan 1, 1968