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By Stephen A. Swan

This Bureau of Mines report discusses research to analyze and evaluate extended bumper systems in order to determine the degree of protection provided to equipment operators in the event of rear-end collisions be-tween off-road rear-dump haulage trucks. The basic characteristics of rear-end collisions were determined, and a detailed analysis of the col-lision dynamics was performed to identify the magnitude and direction of impact loads, the amount of energy that must be absorbed during impact, and the major factors that affect the outcome of a collision. Separate bumper designs were developed to facilitate attachment to four 170-st-capacity haulage truck frame types.

Jan 1, 1987

By R. B. Stotelmeyer

Mineral resources, or a potential for their discovery, occur at 34 localities in the Glacier Peak Wilderness and adjacent areas of the north Cascade Range of Washington (see plate). Eighteen of the mineral deposits are in the established Wilderness, four are in or partly in contiguous RARE II (Roadless Area Review and Evaluation) lands recommended by the Forest Service for addition to the Wilderness (A, D and G6031.), three are in adjacent RARE II lands excluded from wilderness consideration, and nine are in nearby roaded areas excluded from the RARE II inventory. Mineral commodities that might be produced from the Wilderness and recommended additions are gold, silver, copper, lead, zinc, molybdenum, arsenic, cadmium, tungsten, cobalt, limestone (marble), pumice, and volcanic cinders. Mineral production from adjacent lands might include most of these commodities, plus antimony, decorative stone, pyrite, silica, and garnet.

Jan 1, 1982

By Thomas V. Falkie

The purpose of this work was to investigate the rate at which coal is delivered from the underground working face by gathering arm type loaders as employed on continuous mining machines, to identify the factors -- geometrical, geological, mechanical, or procedural which affect the delivery rate, and to develop quantitative rate descriptive equations for the loading function. The mathematical techniques employed were factor analysis and multiple linear regression. It was determined that the coal-cutting function of the continuous mining machine is the factor that primarily influences the loading function. The geometrical factors -- the dimensions of the work area in relation to the dimensions of the mining machine - were the factors of secondary influence. Fifty-five percent of the experimental variation in the loading function was explained in terms of the six most prominent independent variables. It is expected that this work will be useful in operations-research studies as applied to underground coal mining, and with refinement will enable mine planners to select equipment based on the operating characteristics of the equipment and the mining conditions.

Jan 1, 1972

By Lulie H. Crump

Salient information on reserves, production, and consumption of fuels and energy by State is summarized in this Bureau of Mines publication. Reserve and production data are shown for each of the fossil fuels (coal, crude oil, natural gas liquids, and natural gas) and for uranium. The consumption data of each of the major consuming sectors (household-commercial, industrial, transportation, electric power, and miscellaneous) are broken down by energy source (coal, petroleum, natural gas, hydropower, and nuclear). In addition, total energy consumption in the Nation in 1973 is compared with consumption in 1972 and 1974 (preliminary data).

Jan 1, 1976

By John M. Popovich

Disposing of coal mine waste at the surface has been and continues to be a problem which has yet to be resolved within the coal mining industry. A possible solution to this problem is to return the refuse back into the operating underground mine generating the waste material. It is believed that the approach described will provide an inexpensive and pratical solution to the problem. The designed system is installed and operable at the Millers Cove Energy Company, Inc. property in Lee County, Virginia. This system limits surfact facilities to a minimum size. It incorporates state-of-the-art hydraulic transport and backfilling technology and equipment to systematically backfill areas within the active mine. It maximized the benefits of reducing treatment of coal wasts while it minimizes environmental impacts on groundwater. The system approaches the problem in a manner to maximize benefits and minimize risks. The cost of returning coal waste back underground at the Millers Cove site is estimated at $0.67 per ton of marketable coal (1982 dollars), which is slightly higher than their surface disposal cost of $0.61 per ton of marketable mat (1982 dollars). The underground disposal costs do not include cost savings that should be realized within the preparation plant and treatment facilities at the surface. Preliminary tests of the system were conducted at the surface; funding restrictions prevented an in-mine trial. Efforts should continue to demonstrate the feasibility of solving the problem of refuse disposal. The installed system and plant at Millers Cove should provide the opportunity to test an underground disposal operation. This report contains guidelines to pursue this opportunity.

Jan 1, 1986

By Michael S. Miller

In 1987 and 1988, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 3,100-acre Borah Peak Wilderness Study Area (10-047-004) and a 708-acre parcel adjacent to the north in order to evaluate their identified mineral resources. The study area is located in Custer County, ID, about 18 mi northwest from MacKay. The study area lies along the western foothills of the Lost River Range and is underlain by quartzite, sandstone, shale, argillite, dolostone, and limestone. The Lost River fault, a major active fault, lies along the length of the study area. Large alluvial fans spread out from valleys originating east of the study area.

Jan 1, 1989

By George A. Savanick

This paper reviews advances in the art of borehole (slurry) mining made by the Bureau of Mines from 1974 to 1980. The design of a proto-type borehole-mining tool (BMT) developed by the Bureau of Mines is pre-sented along with production data, reclamation data, and an application of the BMT to the mining of coal, uraniferous sandstone, oil sands, and phosphate ore. The BMT was first used near Wilkeson, WA, where steeply pitching metallurgical coal was mined at 8 st/h from a depth of 25 to 75 ft. Next, 940 st of uraniferous sandstone was mined at 8 st/h from a depth of 75 to 100 ft in Natrona County, WY. One thousand short tons of oil sands was mined in Kern County, CA, at the rate of 14 st/h from a depth of 110 to 150 ft in 1979. Most recently, 1,700 st of phosphate ore was produced at 25 st/h from deep (230-to 250-ft) deposits in St. Johns County, FL. Progressive improvements were made in the borehole mining technique. These include the use of the hydrostatic head of a water-filled borehole for roof support, and the development of methods to survey and backfill mined-out cavities.

Jan 1, 1987

By Julius Roth

Flyrock is the source of most of the injuries and property damage in a majority of blasting accidents in surface mines. A quantitative correlation between shot conditions and maximum flyrock range can be used to define a "blasting area" in which no personnel or equipment should be present during a shot. The approach used was to develop a model that correlates shot conditions and initial flyrock velocities and permits computation of flyrock range from ballistic trajectories. The Gurney formula for velocity of explosively-propelled plates or fragments was adapted to explosively-propelled flyrock from vertical rock faces or from bench tops. The modified Gurney formula was then "calibrated" with measured flyrock velocities from mining and explosives literature. Charts were then developed for possible field use which give maximum flyrock range as function of shot conditions. The model indicates that for flyrock from vertical faces, borehole diameter, minimum burden and height of explosive column define maximum flyrock range for a given explosive, shot in a given rock. For flyrock originating from bench tops, flyrock range appears to be controlled by the distance of the top of the explosive column to the borehole collar, by total explosive load per borehole and, to a lesser extent, by borehole diameter.

Jan 1, 1979

By J. L. Thompson

The U.S. Bureau of Mines conducted a water-jet-studies program using a single-bit, in-seam test unit to determine effects of a moderately high-pressure (up to 10,000 psi) water-jet-assisted cutting system on rock weakening. The in-seam test unit was used to obtain cutting force data in tangential, normal, and side force directions. Conical continuous miner and radial longwall miner bits were used to penetrate test samples of coalcrete, Berea sandstone, and Indiana limestone with unconfined compressive strengths of 4,600, 8,000 and 10,000 psi, respectively. Depth of cut in the coalcrete tests was 1 in, with 2-in cut spacing (2:1 ratio). Because of cutting equipment and instrumentation limitations, the Berea sandstone and Indiana lime-stone were cut using a 0.5-in depth of cut and 2-in spacing (4;1 ratio). Bit velocity was maintained at 25 ft/min for both bits. Each specimen and bit type was tested using 0.3-, 0.6-, 0.8-, and 1.0-mm-diam nozzles and water-jet pressures of 2,500, 5,000, 7,500, and 10,000 psig. Water-jet-assisted cutting decreased average resultant conical and radiallongwall bit cutting forces 6.4 and 8.4 pct in coalcrete, 5.5 and 1.4 pct in Berea sandstone, and 2.0 and 5.5 pct in Indiana limestone. Slight reductions of power requirements resulting from water-jet assist were ascertained during these experiments.

Jan 1, 1989

By A. J. Farstad

Recent advances in microcomputer technology have opened the way for systems which can track the location of underground mining personnel from the surface. A computerized system has been designed which is capable of not only tracking the location of the miner but also of monitoring underground parameters, communicating between work stations and sounding alarms when underground conditions are judged to be unsafe. For the system described herein, the locations of the underground personnel are detected by a network of underground terminals which routinely emit RF pulses to interrogate miniature transponders worn by the miners. Each transponder is uniquely programmed to delay its response in such a way that the RF terminal can identify the individual transponders by the time slots in which the responding pulses are received. The underground terminals are then interrogated by the host computer on the surface which keeps a running account on underground mine conditions and personnel. The underground portion of the system is designed to operate even during mine emergencies, deriving its power from rechargeable battery supplies which are float charged during normal operation. Nine mines were visited on this program and the industry reaction to the system was generally favorable. By slanting the system design for daily use in the mine, the chance of its acceptance by the industry is enhanced. Furthermore its likelihood of being operational in the event of an emergency is significantly increased.

Jan 1, 1981

By William C. Hood

A leaching column technique that produces effluent similar in quality to coal mine drainage in the Eastern Interior Basin has been developed. The columns are charged with 1000 grams of crushed overburden and cycled through the leaching process once a week for twelve weeks. Inter-relationships among the important chemical constituents are very similar to those present in actual mine drainage waters, but the overall concentrations of ion are more dilute in the leachates. Multiplying the leachate concentrations by a factor of 4.5 gives values similar to mine waters. Available data suggests that each of the leaching cycles represents about three years of natural weathering, so that the leaching technique can predict the evolution of the mire drainage water over a time span of nearly 40 years. Use of the leaching technique with drill core samples should provide a method of approximating mine drainage quality in advance of mining and should be quite useful in identifying potentially toxic units in the overburden. However, the results should he considered to be a 'worst case' situation because the technique' does not consider the effects of reclamation.

Jan 1, 1984

By George T. Faust

The petrographer engaged in examining the products resulting from the beneficiation of ores and rock minerals is constantly required to develop new means and methods of assaying microscopically the results of such operations. From time to time investigators have published descriptions of apparatus that have aided in solving problems in processes f physical separation. Thus, in 191.9, Coghill and Bonardi 31 published a paper covering the application of the binocular microscope and camera lucida to the microscopic analysis of pulverized ores. Similar work has been published by Schneiderhohn 4/, Schwartz 5/, and Head and his associates6/, 7/, 8/. The present paper goes further and considers application of the polarizing comparison-microscope to problems directly concerned with mineral dressing where it is desirable to compare analogous products, and in addition it suggests new uses in various related fields. This work was conducted under the cooperative agreements of the Southern Experiment Station of the Federal Bureau of Mines and. the University of Alabama.

Jan 1, 1940

By H. C. Fuller

Rhodonite, a manganese silicate, occurs as an important component of extensive veins in the San Juan district of Colorado. Recent work by the Bureau of Mines has demonstrated that typical ores of the area can be upgraded to about 30-percent manganese content. Because of their siliceous nature, such concentrates require further processing to convert the manganese into more usable forms. The investigation described in this report demonstrates the technical feasibility of producing silicomanganese from a rhodonitic concentrate by electric smelting methods. The rhodonitic concentrate used in the smelting research was prepared by dry high-intensity magnetic separation of ore from the Silver Queen vein. The concentrate contained 29 percent manganese, 2 percent iron, and 41 percent silica. The principal minerals in the concentrate were 35 percent rhodonite, 30 percent rhodochrosite, and 25 percent quartz and chalcedony. Limestone was used as the flux and coal was used as the reductant. These minerals were crushed and screened to minus 1/2-inch plus la-mesh size.

Jan 1, 1962

By Stephen C. Tadolini, Raymond A. Mazzoni

The International Ground Control Conference in Mining has always provided an open forum for the publication, presentation, discussion, and often heated debate on roof bolting systems mostly with attention to how, when, and why they work. During the last 24 Conferences at least 170 papers have been presented by International Experts on these “simple” devices that range in length from 30-inches to 20 ft and from 5/8 to 2 inches in diameter. Roof bolts are primarily mechanically anchored, glued, cemented, or driven. Bolts are placed vertically, angled, or tied together with special fixtures (trusses and slings). They have been termed active, passive, stick-slip, and several other descriptive acronyms or mining slang expressions. This retrospective paper will present the changes in bolt types and usage, point out some of the biggest myths and hail the most significant advances (according to the authors’ opinions of course).

By George A. Morgan

The successful expansion of crude oil production begun in late 1977, led to promising development of the nonfuel minerals sector. Although actual production of nonfuel minerals was limited both in variety and in percentage of output on a world scale, the potential for expansion with a rapidly developing infrastructure was significant. The energy base was expanding with construction of two new hydroelectric powerplants in addition to the existing plant near Edea. The Song Loulou plant will have a 240-megawatt capacity, and a hydroelectric plant under construction in the northern part of the country by mainland China will have 72 megawatts of installed capacity. Inflation of between 15% and 20% resulted in a real gross domestic product (GDP) of $2.8 billion2 in fiscal year 1980 (July 31 to June 1), up 6% from that of the previous fiscal year. Petroleum became the leading export item in terms of value, surpassing coffee and cocoa exports. Mineral exports as a whole increased eightfold in value, mainly because of oil sales. Oil exports also caused a reduction in the trade deficit by nearly one-third, and the Government expected its 1980-81 budget to be balanced at $1.17 billion. The Port of Douala accounted for about 8 million tons of cargo, or 93% of total maritime traffic for Cameroon. Expansion plans for the port call for an initial increase to 5 million tons, and a cargo handling capacity of 7.5 million tons in 1985 and 10 million tons by 1990. The Port of Victoria will gain importance with the startup of an oil refinery. The country's third seaport at Kribi was used solely for timber shipments, and capacity at the Port was to triple by 1981. The Government operated its own shipping line with six oceangoing freighters. France was the dominant trading partner, accounting for 25%

Jan 1, 1982

By W. C. Babcock

This report covers Phase V of .a continuing program to apply a new liquid membrane process called coupled transport to the recovery pf metals from hydrometallurgical leach solutions. During this phase of the program, a membrane system of moderate scale was constructed and field-tested at the Exxon Highlands Mine and Mill Co. site near Douglas, Wyoming. The test unit contained four hollow-fiber membrane modules, each with 100 ft2 of membrane area. In the field tests, about 1000 gallons per day of leach solution was processed. The unit was operated on the leach solution for about 50 days. Leach solution entering the unit contained 100 ppm uranium. This concentration was reduced to about 5 ppm by coupled-transport treatment, and the uranium was concentrated to about 2 wt% as a uranyl carbonate product. Under these conditions, a transmembrane uranium flux of about 2.5 lb/ft2-year was obtained. An economic analysis showed that the cost of recovering uranium from this leach solution via coupled trans-port is about $1.20/lb. At higher concentrations of uranium in the leach solution this cost is reduced. For example, at 1000 ppm the cost of uranium recovery is about $0.30/lb.

Jan 1, 1983

By Roy C. Bartholomae

This Bureau of Mines report presents the results of a laboratory investigation of coal cutting mechanics and noise. These experiments were performed using linear cutting apparatus that operates over a broad cutting speed range. The influence of several coal cutting parameters on the noise, force, productivity, and specific energy associated with linear cuts was ascertained. Some basic theoretical aspects of coal cutting mechanics and noise generation are discussed, and the results of the laboratory experiments are used to formulate analytical models of the coal cutting forces and noise. The analytical model for coal cutting noise is then generalized to account for the more important effects of rotary cutting. Based on the generalized model, an estimate of the sound pressure level at an operator's position is made for a typical continuous mining machine. It is concluded that by employing linear rather than rotary cuts, using deeper depths of cut, slower cutting speeds, and more efficient cutting tools, it is possible to reduce the level of coal cutting noise, as well as provide benefits to other important areas of health and safety in underground mining.

Jan 1, 1983

By Mark S. Sanders

Six underground coal mine shuttle cars (three high seam and three low seam) were used to assess visibility using the concept of visual attention locations (VALs) and an improved human eye reference measurement instrument (HERMI Mark II). Each machine was assessed in the inby and outby direction of travel with no canopy and with the canopy in its highest, and lowest position. In addition, the illumination level at each VAL was determined. Results showed that the most important variable determining visibility was operator eye position. When this variable is controlled, the addition of a canopy has no effect on visibility. Further, with eye position controlled, there is no difference in visibility between high and low seam machines. The visibility and illumination assessments found blind spots in the operator's field of view located on the opposite side of the car from the operator and ahead of the machine. Suggestions for reducing the blind spots were made. The report also included a procedure manual for using HERMI and the system of VALs to assess visibility from underground shuttle cars, continuous miners, and scoops.

Jan 1, 1983

By Paul C. Hyndman

No minerals have been produced from the McGraw Creek RARE II area. During the 1982 U.S. Bureau of Mines study, there were no active mines in the area. Limestone occurrences (fig. 1, no. 2), four copper prospects (fig. 1, no. 1, 4, 5, 6), and a prospect with no significant mineral values (fig. 1, no. 3) were examined. A moderate potential for high-calcium limestone resources was estimated between ocurrences within the study area near McGraw and Spring Creeks (fig. 1, no. 2). There is low potential for copper resources at the Argenta Prospect (fig. 1., no. 1) in the study area, and the McDougall Prospect adjacent to the area.

Jan 1, 1983

By L. E. Cardwell

This publication contains routine analyses and related source data for 475 natural gas samples from 17 States and two foreign countries. Of this total, 454 samples were collected during calendar year 1971. The remaining 21 samples were collected during previous years, but releases granting permission to publish the analyses were not received until 1971. All samples were collected as part of a continuous survey of the free world for occurrences of helium in natural gas. This survey has been conducted in the United States by the Bureau of Mines since 1917. In late 1965, the survey was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4863 and 576.4 Thirteen previous publications have presented the results of 9,427 gas analyses prior to 1971. The first three, Bulletins 486,5 576,6 and 617,7 contain analyses and related source data on 5,218 gas samples collected from

Jan 1, 1972