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By Russel Bohn

The purpose of this study was to evaluate the various techniques far mine roadway dust control. This evaluation included (a) the types of dust suppressants available, (b) the interaction of these products with the properties of the roadway surface, and (c) the costs and performance measures of the predominantly used dust suppressants. Over 30 products were identified having a wide range of effectiveness depending largely on the properties of the road base, subsurface, and wearing surface. The effectiveness of a dust suppressant was also found to depend on the application and maintenance procedures employed. As a result of this investigation five dust suppressants were identified s being predominant in the surface mining industry: Coherex, wetting agents, lignin sulfonate, water, and calcium chloride: An approximate cost-effectiveness analysis, limited by the lack of quantitative field performance data, showed that the five suppressants ranked in the order given above, with water being one of the least cost effective. This report also presents an analysis of applicable federal and state regulations.

Jan 1, 1981

By J. H. Jones

The original term of grant No. 1115174 was September 1980 through December 1983. An extended progress report, covering this time period, was forwarded to the Bureau of Hines in January 1984. The principal investigators were given a no-cost extension of their grant to cover the period January through December 1984. The report which follows covers this latter time period only.

Jan 1, 1985

By Larry A. Haas

Carbonyl sulfide (COS) was decomposed to sulfur and CO in a silent electrical discharge. A threshold of about 4 kv at 60 Hz was required to dissociate the gas in a laboratory ozonizer at 790 torr with electrode gaps between 1 and 5.5 mm. Above the threshold value, the reaction rate increased with increasing voltage with helium or nitrogen diluent. With the latter diluent, higher voltages had to be applied to obtain the same yield in the 4-to 12-kv range. The COS decomposition rate increased with COS concentration, but a saturation value was reached at about 10 pct COS. The reaction rate decreased at low linear gas velocities as obtained at lower gas flows, larger electrode gaps, or larger reactor volumes. Increasing gas temperature also decreased the decomposition rate. The presence of solid adsorbents such as quartz wool, bauxite, or charcoal had no significant effect on the reaction rate. The addition of S02 did not affect the COS decomposition rate, but small amounts of water decreased the reaction rate. Over 50 pct of the COS was decomposed at room temperature and atmospheric pressure in a l7-kv ozonizer using a gas containing 0.9 pct COS in helium flowing at a rate of 0.3 liter/min. The average current was less than 5 ma. This method has possible application in eliminating the toxic air pollutant, COS, which is generated in petroleum refineries and in processes involving reactions between sulfurous and carbonaceous materials. Carbon monoxide that is formed can be further oxidized to CO2 after the collection of elemental sulfur.

Jan 1, 1972

By J. H. Nixon

A three phase program evaluated commercial proximity warning devices, developed and designed a microprocessor-based electrostatic field measurement instrument, and utilized this instrument to investigate the electro-static fields about power lines. The Phase I program consisted of test and evaluation of these commercially available proximity devices. The evaluation results were reported in the Phase I report entitlted "Evaluation of Proximity Warning Devices II dated 22 February 1980. The Phase II program resulted in the design and development of a microprocessor-based Distributed Sensor A.C. Electrometer which measures the electrostatic field present at 17 discrete locations along a crane boom. Operator control of the measurement system allows simultaneous electric field measurements from 17 probes, print out of the electric fields measured, and data archiving on magnetic tape for post measurement analysis. Under the Phase III program, electro-static fields around a crane boom were measured by the instrument at 17 high voltage power lines of various voltages and geometries. The electric field data was processed and plotted versus boom distance from the power line. Analysis of the electric field data indicate that the distances at which a single sensor alarm will activate, vary by a factory of 3 to 1. This is due primarily to variations in boom orientation. The results also indicate that in the case of multiple power lines, a single electrostatic field sensor cannot reliably be used to determine the distance from a power line.

Jan 1, 1982

By J. C. Gerdeen

SAP-S information on the following element types are included in this appendix: Type 1. Three-Dimensional Truss and Bolt Element Type 4. Two-Dimensional Finite Elements Type 8. Variable-Number-Nodes Thick Shell and Three-Dimensional Elements Type 9. Two-Dimensional Joint Element (to be used with Type 4 elements) Type 10. Three-Dimensional Joint Element (to be used with Type 8 elements) Additional SAP4 elements, Types 2, 3, 5, 6, 7 and 12, are also contained in SAP-S and information on these elements is readily available in any SAP4 user's manual. These elements are as follows: Type 2. Three-Dimensional Beam Elements Type 3. Plane- Stress Membrane I-r .n Elements Type 5. Three-Dimensional Solid Elements (8 Node: Brick) Type 6. Plate and Shell Elements (Quadrilateral) Type 7. Boundary Elements Type 12. Three-Dimensional Straight or Curved Pipe Elements

Jan 1, 1976

By James C. Barker

The U. S. Bureau of Mines made a reconnaissance In the western Crazy Mountains for cobalt and associated metals as part of the Alaska-wide critical and strategic metals program. The area, located about 75 miles north of Fairbanks in central Alaska, is underlain by complexly faulted, predominantly clastic sedimentary rocks bordering the Tintina Fault system. Above background metal concentrations were found to occur in altered fault zones, tectonic breccias, soils, and ground water seeps and precipitates that either cut or are derived from the faulted clastic sedimentary rocks. Up to 0.115 pct cobalt and more than 2.0 pct zinc were detected in soil samples. Spring precipitates contained up to 1.3 pct zinc, 0.037 pct tungsten, and other metals. Some localities lacked cobalt but contained anomalous amounts of copper, lead, zinc, silver, and other metals. No outcropping of primary metallic minerals was located because of Colluvium and vegetation cover and extensive deep leaching. Therefore, whether the metal values encountered are due to primary deposits with economic development potential or are the results of concentration by ground water from low-grade sources is unknown. The presence of cobalt, nickel and zinc, and the identification of minor tin and tungsten indicate that further investigation is warranted.

Jan 1, 1983

By R. Demont, A. Pranesh, S. Rakheja

Ethical concerns of in-vivo procedures and poor repeatability of non-invasive techniques have been major limitations in estimating vibration-induced spine loads through experiments. The biodynamic models of seated human body exposed to whole-body vibration (WBV) have evolved for defining the frequency-weightings, enhancement of human responses to WBV, and developing anthropodynamic manikins for seating assessment activities. The widely reported mechanical-equivalent models, solely based on through- or to-the-body biodynamic response functions, do not seem to resemble the biomechanical structure and do not yield information on the dynamic loading and deflections of segments of concern, namely the spine. On the other hand, biomechanical models with representative anatomical structure and anthropometry are being attempted to simulate segmental movements and the coupling effects, using Finite elements (FE) or multi-body dynamics (MBD) formalisms, which could provide important insights into the inter-vertebral forces [1]. While the FE models pose considerable complexities primarily related to characteristics of the bio-material properties, the MBD technique with discrete rigid bodies offers the flexibility to create multi-segment models with relative ease and lower computational cost. In this study, a preliminary multibody dynamic model of a seated human body exposed to WBV along the vertical direction is formulated using MSC/ADAMS software. The model validity is demonstrated by comparing selected responses with the available measured data. Methods The seated human is represented by nine rigid body segments, including: head, neck, thoracic and lumbar torso, pelvis, hands and thighs, as shown in Fig. 1. The rigid bodies are coupled through different rotational and translational joints, some of which are force elements to allow vertical translations and sagittal–plane rotations of the segments. The measurements of transmission of vertical vibration through-the-body generally require subjects to voluntarily maintain a vertical head position to reduce head-accelerometer orientation errors. The head–neck–shoulder joint is thus considered to be rigid. The shoulders are assumed to be rigidly attached to the thoracic segment. The torso is made up of three (upper, middle and lower) segments connected by visco-elastic revolute and translational joints to permit relative pitch and vertical motions. The forces and torques generated by the joints are derived assuming linear stiffness and damping properties, which were identified from published studies. The pelvis is connected to the rigid seat by similar elements representing the visco-elastic properties of the buttock tissues. The two thighs are rigidly connected to the pelvis, while the segment masses are chosen from the anthropometric data for the 50th percentile male subject. The initial model parameters for the joints were obtained from [2]. The model was analyzed to determine the force-motion relationship at the buttock-seat interface expressed in terms of

Jan 6, 2006

By John L. Thames

The benefits of water harvesting as an alternative to conventional reclamation were demonstrated on the Peabody Coal mines in Northeast Arizona. The project produced food crops for four years, and demonstrated that a catchment/crop area ratio of about 2.5:1 was sufficient to obtain sufficient water from the 11 inch annual precipitation to produce garden and fruit varieties in quantities equal to or exceeding national production averages. The economic returns exceeded those of the conventional practice of returning the mine area to rangeland by at least ten fold. Subsidence of the regraded spoil was the only major problem in maintaining the system. Although, water harvesting systems have the potential of providing high economic returns and greater social benefits, as demonstrated by this project they are presently at variance with the strip mining regulation.

Jan 1, 1984

By J. M. Pugliese

The Bureau of Mines, in support of its overall goal of helping to meet future U.S. demand for minerals, undertook this study to aid the quarry entrepreneur and/or operator in developing quarries near urban areas. In response to increased environmental concerns, the quarry operator often must take steps beyond those required in the last decade toward gaining permits for quarrying near metropolitan areas. Following the steps suggested in this report should increase the chances to obtain the permits to open and develop a quarry. Each task and question in the general plan flow diagrams are described in detail, with the flow diagrams aimed at the goal of acquiring the necessary permits. The appendixes include (1) types of projects for which Environmental Impact Statements (EIS's) may be prepared and Federal agencies responsible for preparing them, (2) State contacts for information regarding environmental impact assessment requirements and mining and mineral land reclamation laws, (3) a checklist of environmental inventory factors, (4) a tabulation of different regulations that affect mining in Michigan and the number of townships and counties that have each of the listed regulations, and (5) environmental logic associated with site selection. A central recommendation is that the quarry entrepreneur and/or operator coordinate plans at the beginning with local government officials (such as township supervisors and/or city and county planning board members), State and Federal officials, and public groups that will be affected.

Jan 1, 1979

By Samuel M. Bryant

The purpose of this study was to develop procedures to measure Bingham flow properties for mine tailings and to use these to predict the possible consequences of a hypothetical tailings flow failure at the Tenmile Tailings Pond at Climax, Colorado. The consequences of such a failure were found to be minimal, and the failure itself highly; unlikely. Values of Ty (Bingham yield shear strength) and np (plastic viscosity) were measured for 10 materials using results obtained from vaned coaxial viscometer tests and triaxial tests.

Jan 1, 1983

By Travis Q. Lyday

Mineral production in Fiji, a group of 322 volcanic islands and atolls of Melanesia in the southern Pacific Ocean, continued to be dominated by gold. However, the Fijian mineral sector remained a minor factor as a source of export earnings, Government revenues, and employment, generating only 1% of the gross domestic product (GDP), estimated as $1.2 billion.2 The largest and most important mining operation was the Vatukoula gold mine on the north side of Viti Levu, the main island. The Vatukoula Mine has been in prduction since 1932, producing about 3.8 million troy ounces of gold and 1.3 million troy ounces of silver to date. In April 1983, the large Australian mining firm, Western Mining Corp. (WMC), assumed operation of the mine in a joint venture with Emperor Gold Mining Co. Ltd., which operated the mine previously. The WMC takeover of the mine management was expected to bring in additional capital and technological expertise in order to modernize operations, increasing both efficiency and output. During the year, rate of recovery was only about 75% of the gold contained in the ore and only 40% of the contained silver. Mining at the Vatukoula Mine was done using bath opencut and underground methods, with about 60% of the ore mined attributed to the underground operations.

Jan 1, 1985

By Sheridan J. Rodgers

The quantity and behavior of gases in metal and nonmetal mines were monitored to provide background information on feasibility of incipient fire detection systems. Monitoring was conducted during working and nonworking periods at intake air, return air and working places. Gases generated during diesel operations and shot firing were of particular interest. Gases which were monitored were CU, C02, N0, N02 and S02: submicron particulate concentrations were monitored also. Commercially available instruments were used and included nondispersive infrared, electrochemical and chemiluminescent types. The ratios of the various gases generated during diesel operations and shot firing were similar to those expected from an incipient fire, with the exception of the C02/NOx ratio, which is sufficiently different to be considered for early fire warning. Samples taken near leaking bulkheads showed high C02 levels and low C0 levels, the reverse of anticipated behavior in coal mines.

Jan 1, 1976

By D. K. Steele

An 18-in-diam column water elutriator was designed, tested, and operated by the Bureau of Mines for recovering nonferrous mixed metals from automobile shredder rejects. The waver elutriator separated metals from nonmetals contained in shredded nonmagnetic rejects. The unit was constructed and integrated into a local automobile shredding operation. Nonmagnetic rejects from the automobile shredder were fed onto the surface of a column of rising water. Dense materials fell through the rising water and were collected as a sink product at the bottom of the column; medium-density materials were removed as an intermediate product in a water flow through a discharge port located between the overflow and sink; and light materials were immediately carried out in the overflowing water at the top of the column as a float product. Nearly 99 pct of the mixed metals were recovered from the nonmagnetic rejects as a 70-pct-metal concentrate. Other operating conditions yielded a 93.7-pct-pure-metal product resulting in a 93.1-pct metal recovery. Float rejects are combustibles, light plastics, foam rubber, and minimal amounts of coated and uncoated copper wire. The middling discharge contained mainly medium-density rubber, plastics, glass, rock, coated and uncoated copper wire, and frequently some thin-sheet stainless steel and wrought aluminum. Maximum metal recovery in the operating program was achieved using a water velocity of 52 fpm (650 gpm). Maximum purity was obtained with a velocity of 88 fpm (1,100 gpm). .Water was recycled through a 12,000-gal baffled clarifying tank. Entrainment water losses with the float and middling rejects averaged 50 gpt of reject feed. Records maintained by the shredder operator show a 34-pct increase in nonmagnetic metals recovery during a 1-yr operation of the water elutriator as compared to recoveries from a previously used air classification system.

Jan 1, 1983

By Wilbur L. Webb

An electrically powered methane sampling system for application on mining machines was designed, fabricated and laboratory tested. The system will sequentially draw sample air at a controlled rate from up to three machine positions across the mine face and deliver the air to either an approved methane monitor, methanometer or flame safety lamp. The prime considerations in the design were to provide an intrinsically safe, water and dust resistant control box and an explosion-proof power box capable of being operated from the various mining power sources. The power box contains an internal battery that provides operating power prior to mining machine start-up and alter machine shut-down. The internal battery is recharged automatically when mining machine power is available.

Jan 1, 1977

By S. R. Crane

One Bureau of Mines goal is to minimize the undesirable environmental impacts associated with industrial plants emitting waste gases containing S02. To help meet this goal, a regenerable flue gas desulfurization process was developed. This process, known as the citrate process, uses a buffered weak acid solution to absorb S02 from the waste gas. The absorbed S02 is reacted with H2S to precipitate elemental sulfur and regenerate the solution for recycle. The H2S feedstock for the process, if not otherwise available, may be produced by reacting two-thirds of the recovered elemental sulfur with natural gas and steam. Laboratory investigations and pilot plant operations were conducted by the Bureau to determine if H2S from the natural gas, sulfur, and steam reaction was suitable for the citrate process. The laboratory investigations, in which an H2S generator was integrated with other citrate process operations, provided a basis for design and operation of the pilot plant. The objective of the pilot plant was primarily to provide H2S for the citrate pro-cess pilot plant at the Bunker Hill Co. lead smelter in Kellogg, Idaho. The design capacity of the pilot plant was 0.4 to 1.25 tons of H2S per day. The operation demonstrated that (1) a 77-to 79-dry-volume-percent H2S product could be produced from pilot-plant product sulfur, natural gas, and steam; (2) the product R2S regenerated the SO2-loaded citrate solution; and (3) under certain conditions over 95 percent of the natural gas could be converted to H2S.

Jan 1, 1981

By H. G. Hammon

Uranium miners have been shown to develop lung cancer in direct proportion to the time of exposure in the mine and the concentration of radioactivity (cumulative working level).1 Radon gas is continually evolved from the uranium ore, but because of its shoe half-life, 3.82 days, it is soon decomposed into particulate daughter products, which along with the dust in the mine, become deposited in the miners' lungs. At present, massive ventilation is the only effective method of reducing the radioactivity concentration in the mines. However, the Bureau of Mines is evaluating the possibility of using coatings on the mine wall that will have sufficiently low permeability to radon that the gas will decompose into the particulate daughter products before it can permeate the coating. Permanently trapped in the coating, the daughter products would be prevented from dispersing in the mine atmosphere. Lawrence Livermore Laboratory was asked to aid in this investigation. The direct determination of radon permeability is more difficult than that of the other noble gases because of the short half-life of the gas and radioactive contamination of the apparatus. We felt that it should be possible to estimate radon permeation coefficients from other noble gas permeation coefficients. It was noted that the log of the diffusion constants for helium, neon, argon, and krypton, as reported by Meares2,3 plotted to a straight line-against the square of-the gas molecularddia meter. The log of the permeation coefficients also plotted to a straight line against the square of the gas molecular diameter. Thus, by determining the permeation coefficients of such gases as argon and krypton through various films and coatings, it appeared likely that radon permeation coefficients could be estimated. In addition we felt it should be possible to find some relationship between polymer structure and he noble gas permeation coefficient that would aid in the selection of coatings materials as radon barriers.

Jan 1, 1975

By Philip Thompson

The Bureau of Mines investigated a selective flocculation-flotation technique to remove insoluble slimes from low-grade potash ore in a continous 45-kilogram-per-hour (100-pound-per-hour) process investigation unit (PIU). This research is part of the Bureau's program to improve resource recovery from low-grade ores. Results showed that 84 percent of the insoluble slimes were removed from an ore containing 5.5 percent water-insolubles and 14 percent K20 using a Bureau-developed, cationic flocculant-glycol ester-diesel oil reagent. Subsequent potash flotation recovered 75 percent of the potash in a cleaner concentrate assaying 56 percent K20. Concentrate leaching upgraded the product to market specifications of 60 percent K2O. An economic evaluation by the Bureau suggested that the rate of return on investment, after taxes, should be about 20 percent for such an enterprise.

Jan 1, 1980

By J. J. Demeter

Experiments were conducted in 2- and 4-inch-diameter standpipes to evaluate the effectiveness of standpipes as pressure seals. During the experiments, these standpipes conveyed Alan-Wood magnetite (60 to 230 U.S. standard sieve mesh) by gravity flow from one vessel to another of relatively higher pressure. The information obtained has been helpful in a Federal Bureau of Mines investigation of how to make either synthesis gas or hydrogen by a modified steam-iron process employing a continuous recycling stream of granular iron-iron oxide at temperatures of 600° to 900° C. In this process the mixture of granular material flows by gravity from a reduction vessel at low pressures to an oxidation vessel at higher pressures. Data from the 2- and 4-inch-diameter standpipes indicate that it would be practical to use a standpipe as a pressure seal between the reductor and oxidizer. Investigators found that, by gravity flow, the standpipe could convey the Alan-Wood magnetite against pressure gradients up to 1.07 pounds per square inch per foot of column height.

Jan 1, 1961

By Shih-Chi Chang

[An exploratory research is done on untreated coal 1v- using&apos; x-ray crnctinn techniques. Comparison is made on diffraction data before And pct Pr n-tiAne is pressurized (n the coal samples. Although, only ? qualificative -1; t s obtained, the FoIIowing Statement r :&apos; n untreated teal seem- There are other materials in cost. They are accumilated in !e ,r rc r, cin? the microseoric layered structure of coal. 7"P partial graph r :r a&apos; o., «&apos; the i&apos;pr1 cart o ! in cna1 assumes varclor, r,rie&apos;,r: r in&apos;is. R nr ?-&apos;c,.r1&apos;ed I n coal is helm ;n the micrornre s&apos;??ste^ o&apos; c, .:l an&apos; t rr i, ,o <.~i:&apos;epee of Ion(4inc to carton h« x-ray tit If raction me.:SUr&apos;rientq. :t?e me r &apos; nP in r^icropores assumes no structure themselves at room tempera¬FLre. ;inally, some of the other materials in coal are in the form of }vrlrited crystallites and they have anisotropic pro&apos;th hnt&apos;1? in the lavers.]

Jan 1, 2012

By L. C. IlsLey

"The use of trailing cables on cutting machines, loading machines, and similar electrically operated apparatus is recognized as a necessary adjunct to the economical operation of such units. On the other hand, such cables because of their liability to failure from being run over by cars, locomotives, and other track-operated equipment offer one of the greatest hazards - indeed, probably the worst hazard - met with in the operation and maintenance of permissible equipment. Therefore, the Bureau of Mines is seeking ways of making the use of trailing cables less hazardous.Recently the bureau conducted an extensive investigation of both concentric and duplex rubber-sheathed trailing cables at the Pittsburgh Experiment Station. The results of this investigation were published in two reports.3 4In a larger part of portable motor operations in mines a double-conductor cable can be used. The investigation already mentioned indicated that it is feasible to construct a 2-conductor cable that will stand considerable abuse, such as being run over by loaded cars or light-weight locomotives without producing dangerous arcing in the cable either from grounds or short circuits. There are conditions where more than two conductors are necessary, and in such instances it will probably be necessary to use a cable less resistant to this kind of abuse.Schedule 2C, covering the tests of electric motored equipment, was approved February, 1930. This schedule provides for performance tests on trailing cables as follows;Trailing Cable Performance: The following performance test, optional with the manufacturer, is established for determining the suitability of trailing cables for use on permissible equipment. Trailing cables that pass this test will be especially recommended for this service.The cable will be placed across the two rails of a track and a 4-wheeled 7-ton car will be run over it 50 times. The speed of the car shall be approximately 3-1/2 miles per hour and potential shall be applied to the cable during tests. The cable will be shifted in position after each passage of the car thus giving 100 places over which two wheels have passed. To warrant special recommendation of the Bureau, a cable must neither become short-circuited nor grounded either to the rails or wheels in more than 10 per cent of the 100 places.The Bureau of Mines is prepared to conduct tests as outlined in the foregoing paragraphs to determine the suitability of trailing cables for use on permissible equipment. Application for such tests should be made to the Director, Bureau of Mines, Washington, D. C. Each application should be accompanied by a check for $25.00, made payable to the Treasurer of the United States, to cover the expense of conducting the test on a given size and make of cable."

Apr 1, 1930