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By W. A. Cole

The sulfur shortage that existed during the Korean conflict stimulated interest in coal measures as possible sources of sulfur. One of the areas brought to the attention of the Bureau of Mines was in Marion County, Iowa, where comparatively high-sulfur coals and other marcasite-bearing strata were known to occur. A Bureau of Mines engineer inspected the marcasite occurrence on December 4, 1954; this prompted further work on the Iowa coals and associated formations as a source of iron sulfides. An investigation of the Iowa high-sulfur coals was undertaken including core drilling, field reconnaissance, and compilation of data pertinent to consideration of the following: 1. Upgrading Iowa coal by mechanical cleaning and the feasibility of recovering sulfur from coal brasses. 2. Possibility of processing the high-sulfur coals by adaptation of methods employed in processing industrial gases to produce sulfur and sulfur products. 3. Possibility of finding concentrations of iron sulfides in associated rock formations in sufficient quantity for economical recovery.

Jan 1, 1957

By John Durkin

Information on vertical magnetic noise in the voice frequency band, both within and above coal mines, is needed for the evaluation of through-the-earth baseband electromagnetic communications at mines where horizontal loop antennas are used. This report discusses the theory of the source of electromagnetic noise, the propagation of this noise to an observation point above a mine, and its interaction with the local earth conductivity structure, which gives rise to vertical magnetic noise. The relationship of surface noise to underground noise is also discussed. Bureau of Mines investigators made surface and underground vertical magnetic noise measurements at a number of coal mines located through- out the United States. These data were modeled through regression analysis to characterize expected noise levels. The results are presented, including results in one-third octaves for use in evaluating the expected performance of through-the-earth communication systems by articulation-index studies.

By F. L. Wideman

SPURRED by demands of a buoyant economy for mineral products, output from mines in the United States established a new record. Removal of waste material, necessary for the extraction of economic minerals, kept pace with mine production. Earth moving by these two activities exceeded 3 billion tons, an increase of 5 percent over that of 1963. Crude materials from which metal or nonmetal products were derived accounted for 75 percent of the total. The remainder, mostly worthless, was classified as waste. Changes in the minerals industry result from many causes. Technological trends and labor productivity are among several significant and interrelated indexes that assist in the analysis of the changes. Therefore, a. study of productivity is helpful in measuring technological growth in mining. Concepts of productivity tend to vary with the purpose for which the term is used; frequently, productivity is expressed in terms of units of output per unit of labor, such as tons of ore per man-hour or man-shift. Comparisons of levels of productivity for a group of products are usually made using composites of output. Data for all metal and nonmetal mines except gold, silver, mercury, platinum metals group, and sand and grave were used to compile the composite for determining productivity for 1960-64. Copper ore, iron ore, and phosphate rock are mined mainly by surface methods, but characteristics of the deposits and differences in processing the crude material affect production of the commodities. Therefore, productivity data for these selected segments of the minerals industry reflect the influence of physical conditions on the exploitation of them.

Jan 1, 1965

By Rose L. Ballard

This chapter summarizes data on crude nonfuel mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Included also 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 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 output from auxiliary processing at or near the mines. Because of inadequacies in the statistics available, some series deviate from the foregoing definition. For gold, silver, copper, lead, zinc, and tin, the quantities are recorded on a mine basis (as the recoverable content of ore sold or treated). However, the values assigned to these quantities are based on the average selling price of refined metal, not the mine value. Mercury is measured as recovered metal and valued at the average New York price for the metal.

Jan 1, 1981

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 Alan R. Buehler

The Bureau of Mines conducted a mineral investigation of the 32,270-hectare Cache Peak study area in 1992; the area had been proposed as wilderness. Bureau personnel examined and sampled prospect workings; 50 rock and placer samples were taken during the investigation. The study area is centered about 25 km southeast of Challis, Idaho, in the Challis National Forest. According to May, 1993, Bureau of Land Management mining claim records there were no current mining claims located inside the study area. Up to 100 claims may have been located in the study area in the past. Gold, silver, copper, lead, zinc: Significant analyses, poor exposure precludes resource estimate. Limestone: More than I billion tonnes may be chemically suitable for a variety of uses, markets too distant to favor mining. Dolomite: More than 1 billion tonnes may be chemically suitable for producing magnesium metal, markets too distant to favor mining. Sand and Gravel: Several million m3, but markets and transportation costs do not favor mining. Chalcedonic nodules: Two localities in the study area may be of interest to hobbyists who cut and polish stone. There is no reported past production from the study area.

Jan 1, 1993

By Robert G. Yewen, Ronald S. Conti

Underground mines rely on alarm systems, such as stench gas, audible or visual alarms, pager phones, telephones, and messengers to warn miners of a fire or other emergency. These systems are often slow, unreliable, and limited in mine coverage. This report describes the evaluation of a wireless signaling and warning system for underground mines. This system is applicable to both coal and noncoal mines. The work was conducted by the National Institute for Occupational Safety and Health in cooperation with TeleMagnetic Signalling Systems (TSS) under Cooperative3Research and Development Agreement No. BOM-CRDA-6200-0119. A TSS wireless ultra-low-frequency electromagnetic signaling system was installed at the Experimental Mine at Lake Lynn Laboratory near Fairchance, Fayette County, PA. A commercial smoke sensor was interfaced to a remote portable transmitter, and the alarm of the sensor was used to trigger the central evacuation and paging transmitter system during experimental mine fires. The underground/surface receivers flashed cap lamps and activated remote devices, such as strobe lights, within 30 to 40 s after the encoded signal was received. Evaluation results showed full-mine coverage of the electromagnetic field and that the encoded signal was received at the farthest point underground and on the surface perimeter.

Jan 5, 1997

By D. E. Seizinger

Analytical methods for oxygenates in exhaust gases were studied, and emissions of these compounds from automotive engines were measured with and without an oxidation catalyst in the exhaust system. Hydrocarbons, simple mixtures of hydrocarbons, and a single gasoline were used as fuels. With the more complex gasoline, successful analysis was possible only with exhaust from the catalytic system which preferentially converted and thus removed interfering hydrocarbon species. However, it was shown that an estimate of the oxygenate yield from gasoline used in a noncatalytic system can be synthesized from data obtained with simple fuels. Such synthesized data were used for comparison of noncatalytic with catalytic systems. Compared with those of previous studies, results of this work indicate that the action of the catalyst introduced no new oxygenates and reduced both the carbonyl and the total of oxygenates. It is concluded that the compositional character and class distribution of oxygenates in exhaust from catalytic systems may differ significantly from the composition and distribution for oxygenates not subjected to catalytic conversion. The findings also support previous estimates that noncarbonyls may constitute a significant fraction of exhaust oxygenates and may warrant attention in procedures for measurement of the oxygenates.

Jan 1, 1973

By Allen D. Look, J. Howard Bird

"INTRODUCTION The Phelps-Dodge Corp. New Cornelia Branch open-pit copper mine operated without a fatality in the drilling and blasting department from December 13, 1937, to April 1, 1947, and continuing.Between the dates named the explosives crews had a total of 746,520 man-hours of exposure and handled 12,000 tons of explosives, over 770,000 detonators, 2,300,000 feet of fuse, and 7,700,000 feet of Primacord in loading holes to break 116,780,000 tons of material.It is the purpose of this paper to record the procautions taken to insure safe handling of explosives at this operation where safety is definitely a matter of forethought rather than chance.GENERAL INFORMATIONThe New Cornelia Branch open-pit mine operates on a large, low-grade, disseminated-copper deposit about one-half mile south of Ajo, Ariz. The pit is approximately oval; the ore body being some 4,800 feet long and 2,750 feet wide. Ore is mined with electric shovels loading into railroad cars. All benches in- the pit are 40 feet in height except two, which are 60 feet high.The New Cornelia ore body differs from most porphyry-copper deposits in being hard and siliceous. In common with the other low-grade porphyry-copper deposits, continued operation is possible only with economical handling of large tonnages. This has necessitated a great deal of study in the evolution of a safe and efficient method of handling the large quantities of explosives needed in breaking this hard-rock material."

Feb 1, 1948

By John C. Edwards

The Bureau of Mines has developed a time-dependent droplet vaporization model (in the absence of forced convection) that can be applied to the vaporization of liquid Halon 1301 droplets (vapor pressure at 300 K = 14 atm) sprayed from an extinguisher. It was found that rapid surface vaporization quickly lowers the droplets' surface temperature very near to the boiling temperature, and the vaporization becomes diffusion controlled. Although the lifetime of the droplet is proportional to the square of the initial radius of the droplet, the elapsed time prior to complete droplet vaporization is not proportional to the square of the droplet radius, as an equilibrium model would indicate.

Jan 1, 1982

By Allen D. Look, Stanley M. Walker, Van Fleet. Leonard A.

"INTRODUCTION The hazards to be encountered in temporarily or permanently abandoned underground mines, quarries, and open pits are numerous, and hardly a year goes by without several reported cases of fatal or serious injuries occurring to unwary people who enter these old mines. Persons visiting mining areas for the first time, tourists, and young people, especially, proceeding in the spirit of adventure common to youth or to the venturesome have suffered many such accidents during exploration trips. The possibility of salvaging salable or usable equipment prompts men and boys to go into old mines, some through ignorance of the attendant hazards, but some jeopardize their lives hopeful of gain (in some cases pitifully small), thinking the hazards are not dangerous and that they can ""get away with it.""Persons fall into unprotected holes, some seek shelter from storms under high banks, and quarries and open pits are often chosen as places for recreation, picnics, swimming, etc; all such uses of these places are likely to be hazardous and to lead to accidents, frequently fatal.These hazards are known to men in the mining profession, and the danger to the public is realized by most of them. A solution to the problem has been sought at many mining meetings, and it is recognized that complete prevention of entry into old mine workings and surface mining areas is the ideal solution, but this, unfortunately, is not always practical; better education of the public, particularly children, should help to reduce the number of such accidents and will be effective in direct proportion to the extent and vividness of such education."

Aug 1, 1948

By Rose L. Ballard

This chapter summarizes data on crude nonfuel mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Included also are the 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 be measured at any of several stages of extraction and processing, the stage of measurement used in this chapter is what is ordinarily 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, 1982

By John L. Ellenberger

The Bureau of Mines investigated the occurrence of slickensides in mine roof in the Pittsburgh coalbed in a portion of the Valley Camp No.3 mine in southwestern Pennsylvania to improve the potential for prediction of slicken-sided zones and determine the orientations of the most prominent slickensided planes. Two distinct types of slickensides were identified; those which were associated with clay veins observed in the coalbed (genetic), and those which were unrelated to any visible structure (nongenetic). The study draws three conclusions: (1) Nongenetic slickensides are not the result of tectonic forces, (2) both genetic and nongenetic slickensides tend to dip at an angle of 30°, and (3) genetic slickensides tend to be alined parallel to the trend of the clay vein and usually dip toward the center of the clay vein. A schematic roof bolting plan is presented that may provide improved roof support where slickensides are present. Roof stability could be improved by supplemental bolting in the direction normal to the plane of slickensides.

Jan 1, 1979

By Guy A. Johnson

This Bureau of Mines report summarizes the results of efforts to develop reasonably priced, reliable mine shaft fire and smoke protection hardware for metal and nonmetal mines. The hardware was incorporated into a viable prototype system that would minimize fire and smoke hazards. The design of the system had to be sufficiently flexible to be utilized in a wide variety of metal and nonmetal mine shaft and shaft station configurations. As a result of long-term, rugged field tests, an improved (second generation) system was developed. The hardware is now commercially available.

Jan 1, 1978

By W. W. Weller

This report provides low-temperature heat-capacity data and entropies at 298.15° K. for magnesium metavanadate (MgV206) and magnesium pyrovanadate (Mg2V207). The work completes low-temperature measurements planned for alkaline-earth vanadates; an earlier report dealt with calcium vanadates.4 No similar data for these compounds have been published previously. Free energy of formation values at 298.15° K. were derived by combination of the present entropy values with heat of formation data. MATERIALS The materials used in the measurements were portions of the samples described in a previous Bureau of Mines publication by King, Koehler and Adami.5 Methods of preparation, chemical analyses, and X-ray examinations are covered in this paper. The indicated purity of the samples was 99.9 pct.

Jan 1, 1962

The Bahamas Oil Refining Co. (BORCO) refinery in Freeport continued to operate at less than half its full 500,000-barrel-per-day capacity. Although owned through subsidiaries by the Carey Energy Corp (65%) and Standard Oil Co. of California (35%), BORCO is ineligible for participation in the Crude Oil Entitlements Program granted to companies operating within the United States proper or its territories. Like some other Caribbean refineries, BORCO has suffered a loss of normal market outlet due to the wt advantage afforded U.S. refineries by the Entitlements Program. Saudi Arabia, Nigeria, and Libya are the major suppliers of crude for the refinery. Its principal products, motor spirits, aviation fuel, distillate fuels, and residual fuel oils, were marketed in the United States and Puerto Rim. The Government-owned Bahamas Development Corp. and Burmah Oil Co. Ltd., held discussions pertaining to a renegotiation of Burmah Oil's management contract for the Grand Bahama Oil Transshipment terminal. The desired contract modifications were not made public but financial problems have plagued the terminal and its operation since construction started in 1972.

Jan 1, 1981

By M. L. Whisman

Several commercial processes for reclaiming used lubricating oil were duplicated on a laboratory bench scale. Laboratory tests were selected and in some instances modified to determine the physical properties of each oil produced. In addition, the hydrocarbon composition of some samples was determined using a liquid chromatographic technique, and compared with the composition of new oil in order to determine the severity of the re-refining technique. Selected samples of reprocessed oil were reformulated with an additive package for further estimates of quality as determined by wear, corrosion, foaming, and oxidation stability tests. Additionally, several samples of commercially re-refined oil and new oil were obtained and physical properties were determined for comparative studies.

Jan 1, 1974

By David A. Monaghan, Kenneth R. Maser, Adi R. Gurdar, D. Randolph Berry

9. Remote Sealing System Sensitivity 9. 1 Introduction In the previous sections a description of the overall system has been presented along with detailed descriptions of the equipment and techniques employed with the preliminary probing system, the seal em¬placement system and the seal checking system. In addition, the use of these subsystems in a specific mine application has been described in considerable detail. A broad range of parameters of interest was specified in the contract, as summarized in Section 1. 3. Most of these are a function of the general location; i. e. , the location of the mine, and the specific location; i. e. , the location of the boreholes. These parameters of interest include passage size, shape, depth, slope and water con¬ditions. The length, diameter and location of the boreholes within the mine passage and on the surface are critical parameters as well. A few additional parameters may affect one or more of the remote sealing subsystems. These include temperature, topography, rock and soil conditions, and underground water. While variation in these parameters will not render the system inoperative, consideration of them in the planning stages will simplify and expedite the field operation. In the following sections the effect of the various parameters on the remote sealing operation will be discussed. For clarity, the several tasks, borehole drilling and casing, preliminary probing, fly ash delivery, foam topping and seal checking, will each be considered separately.

Jan 1, 1973

By Lisa Steiner, Robin Burgess-Limerick

In 2004, there were 646 underground coal mines in the USA employing 37,445 miners. These mines reported 3556 injuries to MSHA that year - 17% were associated with bolting machines (593 injuries), 8% with continuous miners (283 injuries), and 4% each with Scoop/LHD (1 51 injuries), shuttle cars (134 injuries), and personnel transport (145 injuries). The use of the frequency of reported injuries for the prioritization of risk control strategies has limitations because of the tendency to underestimate the importance of relatively rare but high-consequence events. Injury reports also underestimate the contribution of risk factors such as whole body vibration, which have a long-term cumulative contribution to an elevated risk of injury. However, taking these limitations into consideration, the results of the injury narrative analysis suggest the following hazards as the highest priority for elimination or control: • rock falling from supported roof • inadvertent or incorrect operation of bolting controls • handling continuous miner cable • collisions while driving LHD/Scoop, shuttle cars and personnel transport • rough road while driving or traveling in LHD/Scoop, SC & PT

Develop a means for analyzing seismic crosshole data to predict and monitor the Flow of leach solution during in situ mining. Background Improvements in predicting and monitoring in situ leach solution flow would aid in planning well field configurations. These improvements would also facilitate permit application by assuring regulatory agencies that leach solution would not escape from a well field undetected. Seismic tomography can detect fractured zones, which enables the prediction of probable flow paths, and it is a promising technique for monitoring leach solution injected above the water table. Tomographic analysis of crosshole seismic data provides a two-dimensional picture of the distribution of seismic velocities between the transmitter and receiver boreholes. The positions of fractured zones and of leach solution can then be inferred from the seismic velocities.

Jan 1, 1989