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By Haskiel R. Shell

While the original purpose of the Bureau of Mines work on fluorine micas was to synthesize large single crystals or film suitable to replace natural muscovite or phlogopite, the objective was broadened to include development of the many possible fluorine micas as a class of new, unique materials. Several methods were developed for the synthesis of the fluorine micas at atmospheric pressure: Solid state reaction, melting in crucibles, internal resistance electric melting, and arc resistance electric melting. The latter two methods are now med commercially. A variety of fluoromicas were synthesized by isomorphic substitution including disilicic, trisilicic, and tetrasilicic. Fluorophlogopite, KMg3AlSi3O10F2, is the fluoromica most widely used. While most of the fluoromicas are completely stable to water, many water-swelling fluoromicas and fluoromontmorrilonoids were synthesized. Single crystals or film of the fluorine micas were grown to 2 inches or more by a number of methods, but none has as yet proved economical. In the report, detailed data and descriptions are given on compositions, syntheses, products, and uses, and on the properties including physical, dielectric, chemical, X-ray, optical, and structural.

Jan 1, 1969

By Kray Luxbacher, Mario Karfakis, Erik Westman, Peter Swanson

Three-dimensional velocity tomograms were generated to image the stress redistribution around an underground coal longwall panel to produce a better understanding of the mechanisms that lead to ground failure, especially rockbursts. Mining-induced microseismic events provided passive sources for the three-dimensional velocity tomography. Surface-mounted geophones monitored microseismic activity for 18 days. Eighteen tomograms were generated and high-velocity regions correlated with high abutment stresses predicted by numerical modeling. Additionally, the high-velocity regions were observed to redistribute as the longwall face retreated, indicating that velocity tomography may be an appropriate technology for monitoring stress redistribution in underground mines.

By George L. Gates

[When clays e.re mixe~ "Jith "~later to nake mud fluids f'ol' use in :irilling ','Iells "for oil and gar: h;:r vue :;'0 tary me thee. t 18 liquid mij~ tUl"es have certair.. phypicr..l characteri.",t.ics that vary ",dth t e Qlldlltit.y find]

Jan 1, 1941

By Russell E. Griffin

Dielectric constants and dissipation factors were measured by the Bureau of Mines for 13 simulated lunar rocks over the 20-to 100-megahertz frequency range by means of the susceptance-variation method. Measurements were made at room temperature and normal atmospheric pressure. Results are presented and some comparison is made with data reported by others. The rocks used include a broad range of physical characteristics and chemical compositions from the large areas of volcanism in Oregon and northern California, and two nonvolcanic types. These rocks make up a suite of rock standards used by a group of laboratories engaged in lunar research. The data presented will add to the basic scientific and engineering knowledge needed to utilize extra-terrestrial mineral resources for support of future space missions.

Jan 1, 1974

By E. S. Leaver

The gold that is not recovered by a particular process is refractory to that process. A study to determine how the refractory gold is associated in the ore constituents usually indicates the needed improvement in the process or additional methods for bettering recovery. In preliminary work, segregation of the various minerals, gangue or impurities, and data showing the reactions of each in the recovery method readily confines the refractory gold to a certain part on which extensive research can be directed. In this dissecting plan, the microscope is an important aid in locating the refractory gold but should be supplemented by chemical tests.

Jan 1, 1934

By Jeffrey Johnson, Carl Sunderman, Ted Williams, Stephen Signer, Douglas Bayer

To measure the loading behavior of friction bolts, researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) installed strain gauges on the interior of friction bolts and developed a battery-powered miniature data acquisition system (MIDAS) that fits inside the hollow portion of the friction bolt. The advantages of this system are that it is protected from face blasts and eliminates the need for external wiring. Laboratory pull-out tests showed that friction bolts installed in a concrete block with resin were loaded to about 1.8 tons/ft of bolt length; bolts installed without resin were loaded to 1.3 tons/ft. Three strain-gauged friction bolts were installed at Hecla Mining Company’s Gold Hunter Mine, Mullan, ID, in the wall or rib of a mechanized cut-and-fill stope. The object of these tests was to establish an installation procedure for the bolt-and-MIDAS combination and to evaluate performance. The stope was advanced in three 15-ft increments and strains induced in the rock bolts by stress changes in the rock were recorded every 30 minutes. The MIDAS proved to be rugged enough to withstand the shock and vibration from nearby (5 ft) face blasting. Data from MIDAS showed that the friction bolt installed with resin was the most sensitive to each face advance. It showed a steady increase in loading to a maximum value of 1000 microstrain. The friction bolt installed without resin showed stick-slip behavior with loads to a maximum of 400 microstrain before the stope was completed.

By Branch of Editorial Services

"The Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau of Mines to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue of the Bureau of Mines List of Publications and Articles describes reports and articles published during the period January 1, 1980, to December 31, 1984. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960;1 the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960;2 the 5-year lists of publications and articles from January 1, 1960, to December 31, 1964,3 from January 1, 1965, to December 31, 1969,4 from January 1, 1970, to December 31, 1974,5 and from January 1, 1975, to December 31, 1979;6 and the annual lists of Bureau publications and articles from January 1 to December 31, 1980,7 from January 1 to December 31, 1981,8 from January 1 to December 31, 1982,9 and from January 1 to December 31, 1983. 10"

Jan 1, 1985

By Dwight L. Sawyer

To provide technology that can help decrease the dependence of the U.S. aluminum industry on imported bauxite, the main ore of aluminum, the Bureau of Mines is investigating the extraction of aluminum from abundant domestic reserves of kaolinitic clay. Miniplant studies of the continuous leaching of calcined kaolin with boiling 25-pct HC1 acid resulted in a 93- to 99-pct extraction of the acid-soluble alumina in the calcined kaolin feed. Data are presented for an acid leaching study carried out in three or four continuously stirred tank reactors (CSTR) in series, feed rates of 100 to 250 lb/hr of calcined kaolin, and total nominal residence times of 0.7 to 2.3 hr. A material balance for a 176-lb/hr calcined kaolin feed rate in a circuit consisting of three reactors, four classifiers, and five thickeners is given. Data provide detailed compositional and physical information for calcined kaolin, process liquors, and acid-leached residue solids.

Jan 1, 1983

By Stephen C. Tadolini, Peter (Yunqing) Zhang

A unique circumstance created by monitoring a pre-driven longwall recovery room permitted measuring the stresses of a coal pillar throughout its entire life cycle in less than a week. A fender pillar, created in approximately the middle of a longwall panel at a depth of 650 ft, transformed from a solid barrier pillar - to a yielding pillar - to a residual pillar as 3 ft slices were methodically removed with the longwall shearer. The complete transformation, or life cycle, took place in less than 12 hours. The stresses were quickly transferred from the pillar onto the standing pumpable concrete supports and into the outby pillars. Roof to floor closure measurements, combined with the timing of the pillar behavior, provides a detailed look at the uncontrollable convergence of underground mine openings. Pillars remain the most important form of “primary support” and understanding these life cycles is vital for safe and efficient mine design, in both room and pillar and longwall panel extractions.

By F. L. Wideman

This paper is one of a series on mining methods being published by the Bureau of Mines. It describes briefly mining practices at the Sunrise iron mine of the Colorado Fuel & Iron Corp., Platte County, Wyo. The Sunrise mine is in the Hartville iron district in east-central Wyoming (fig. 1). The district covers part of the Hartville Mountains, a region of moderate relief in which erosional features have been formed by the dissection of a low plateau. Altitudes vary from 4,300 feet along the North Platte River to 6,000 feet in the uplift. The climate is semiarid, with hot summers and winter temperatures below zero for short periods. Grasses, cacti, yucca, and low desert shrubs grow at lower elevations. Cottonwood and boxelder trees and willows grow along permanent streams; juniper and coniferous trees are confined to the higher elevations.

Jan 1, 1956

By S. J. Page, R. A. Jankowski, J. A. Organiscak

The U.S. Bureau of Mines investigated the relationship of bituminous coal seam parameters and the amount of airborne respirable dust generated at longwalls. Dust and coal samples were obtained from 20 longwalls operating in geographically representative coalfields throughout the United States. Statistical analyses of coal seam parameters and airborne respirable dust measurements indicate a likely causal relationship between seam type and respirable dust. Low-ash, high-volatile coal seams were associated with higher airborne respirable dust levels. A negative linear correlation (significant at the 95-pct confidence level) was observed between the seam's ash content and airborne respirable dust, explaining up to 18 pct (R2 = 0.18) of headgate dust level variation and up to 15 pct of tailgate dust level variation. Volatile matter was found to have a positive linear correlation with tailgate dust level, explaining 16 pct of the variation. Further data examination indicates that these relationships with dust are most likely nonlinear, because of improved R2 values over the linear correlations. However, a notable portion of longwall dust production is influenced by other operational parameters, so additional research under more controlled conditions is needed to determine the seam's causative functions.

Jan 1, 1992

By G. L. Oldright, Virgil Miller

"This paper is the tenth 4 of a series on smelting in the lead blast furnace, and the fifth 5 on modifications brought about by the introduction of richer charges.ACKNOWLEDGMENTSAll of the data on handling rich charges in lead smelting given in this recent set of five articles describing the results of a cooperative study by the United States Bureau of Mines and the University of Utah were obtained through the courtesy and with the cooperation of the staff of the Bunker Hill & Sullivan Mining & Concentrating Co. at Kellogg, Idaho. The authors acknowledge with appreciation the assistance given by Stanly A. Easton, vice.-president and general manager, F. M. Smith, smelter director, and A. F. Beasley, smelter superintendent, whose generosity, sympathy, and assistance made it possible to obtain this information for the mining industry.GENERAL DISCUSSIONWhen the charge has been dropped into the lead blast furnace, it is out of control of the operator to the extent that, whatever the material is, it must practically all be melted and run out of the blast furnace. The necessary uniformity of mixture to produce slags of regular composition and the choice of the slag—forming ingredients and products to be formed can be made only before the charge to dropped.It was found (R.I. 3096) at Kellogg, where the charge is mostly sinter, that the ratio of the slag—forming ingredients taken from each tuyere was nearly constant, in contrast to the irregular composition of slags taken similarly from a furnace whose charge consisted of ingredients differing greatly in chemical and physical nature, including size. If the charge consists almost entirely of sinter, the blast furnace should then operate more uniformly."

Aug 1, 1932

By E. Rupprecht, J. Volkwein, K. Cashdollar, R. Gürtunca

The National Institute for Occupational Safety and Health (NIOSH) mining research program at the Pittsburgh Research Laboratory (PRL), includes the areas of coal mine dust control and monitoring, and explosion prevention. One very important project at PRL is development of a continuous recording person-wearable respirable dust monitor. This Personal Dust Monitor (PDM) is a respirable dust sampler and gravimetric -equivalent analysis instrument that is part of a belt-worn mine cap lamp battery unit. Prototypes were successfully tested in the laboratory and in four underground coal mines. The PDM testing demonstrated that it was convenient to wear and use, robust, and provided accurate and timely data. NOSH is also conducting research in the program area of coal mine explosion prevention, suppression, and mitigation. Aspects of this research program include: full scale explosion research, laboratory scale research, frictional ignition of methane, mine ventilation seal construction, prediction of coal mine methane emissions, mine monitoring systems, flame cutting and welding operations, spontaneous combustion, and emergency preparedness.

By C. C. Anderson

"While conducting investigations in connection with the helium program of the Bureau of Mines, the Cryogenic Laboratory has improved an apparatus for the rapid and accurate determination of the helium content of natural gas and gaseous mixtures derived from that source. The separation of helium is effected by the use of activated coconut charcoal which, when cooled to liquid-air temperatures, absorbs the nitrogen and other constituents of the gas, leaving the helium in a. spectroscopically pure state. This absorptive property of activated charcoal was discovered- by Dewar3/ in 1875. Several years later, while conducting their original researches on helium in natural gas, Cady and McFarland employed the charcoal method for the absorption and removal of the common constituents of natural gas and constructed an efficient apparatus in which this operation could be effected.4/ Shortly after initiating the government's helium activities during the World War period, the Bureau of Mines adopted, with Minor modifications, the Cady and McFarland apparatus and method of analysis. Seibel.5./ described this modified apparatus and method of procedure as part of a publication on helium-bearing natural gas. Subsequently, the Bureau's apparatus for helium analysis has been simplified and improved to facilitate more rapid and positive operation. The apparatus and method of procedure now being used by the Bureau of Mines Cryogenic Laboratory arc described in this paper.The personnel of the Bureau of Mines Cryogenic Laboratory has improved and brought the helium apparatus described herein to its present state of perfection. The writer's contributions have been-of minor importance, and he wishes to give the various members and former members of the laboratory staff full credit for the improvements they have made. He also desires to express his appreciation for suggestions and criticisms offered during the preparation of this paper to the following members of the Petroleum and Natural Gas Division, Bureau of Mines, which now includes the Amarillo Helium Plant and Cryogenic Laboratory: H. A. Cattell, chief engineer; C. W. Seibel, supervising engineer of the Amarillo Helium Plant; W. M. Deaton, chemist-in-charge of the Cryogenic Laboratory; and H. S. Kennedy.The quantitative determination of helium in a gaseous mixture is accomplished by the removal of the other constituents from the sample, either by chemical or physical Means, leaving only the helium which can be measured directly. Chemical methods, when applied to natural gas, require the burning of the hydrocarbons in oxygen, the, absorption of the resulting carbon dioxide in a caustic solution, the removal of the excess oxygen in a suitable solution such as an alkaline pyrogallate, and the elimination of nitrogen by sparking or by combination with hot calcium or magnesium.. Such procedures are very slow and tedious compared with the physical method which employs the absorptive property of activated charcoal to effect the separation of the other constituents from the helium."

Jun 1, 1934

By Robert F. Randolph

Introduction This paper is a descriptive analysis of injuries and fatalities at small surface bituminous coalmining companies in Pennsylvania. The purpose of analyzing a specific industry sector and location is to identify issues that might be missed in a wider analysis. Other studies of small mine safety (e.g., Peters and Fotta, 1994, Randolph and Boldt, 1997) have shown that the relationship between safety and mine size is not a simple one. Some injury types occur at higher rates at small mines, while others occur at lower rates. Consequently, an analysis limited to a specific type of mining can help identify hazards and issues specific to that sector. The results of this analysis will be useful for directing training, intervention, and research efforts towards the most prevalent causal factors and incident types. Procedures and Definitions Data sources The primary sources of data for this analysis were files provided by MSHA containing information collected under Title 30 Code of Federal Regulations, Part 50. These files, commonly referred to as “Part 50 data”, are provided though MSHA’s Program Evaluation and Information Resources directorate. Two primary types of injuries were selected from the Part 50data: Fatalities (MSHA “degree of injury” code 1) and lost-time injuries, otherwise known as nonfatal with days lost (MSHA “degree of injury” codes 2 through 5). Lost-time injuries involve either actual days away from work or days of restricted activity or both. Fatality and lost-time injury incidence rates were calculated using the standard MSHA formula: Number of injuries per 200,000 employee-hours. Additional information on company sizes and mine ownership was provided by the Pennsylvania State University College of Earth and Mineral Sciences. Time span A five-year time span was selected for this study. More than a single year of safety experience is usually needed to capture a broad range of incident types. Many types of injuries, especially fatal injuries, can be extremely rare, and may be missed if too short a time span is selected. However, a time span that extends too far back may begin to suffer historical threats to validity. That is, incidents that occurred several years ago may be caused by hazards that have since been remedied or may be related to mining practices and conditions that no longer exist. A five-year span offers a practical compromise between these two concerns. Consequently, the MSHA Part 50 data files from 1993 through 1997 were used. The 1997 file was in “preliminary” form at the time of the study, so small variations from the final 1997 “close out” file can be expected. Based on past experience, we do not expect the close-out variations to have a significant impact on the findings.

By Stephen C. Tadolini

The U.S. Bureau of Mines has developed ultrasonic measurement instrumentation capable of measuring strains and elongations on tensioned and untensioned mine roof bolting systems. This report evaluates the pulsed-phase-lock-loop and pulse-echo systems. The pulse-echo systems measure time of flight of a signal through the bolt. The ultrasonic instrument converts the measurement into elongations or stress. The most recent Bureau instrument development converts travel-time measurements directly into elongation, load, stress, and torque by simple data manipulation from the keyboard. Bolt preparation and instrument calibration are described in detail.

Jan 1, 1990

By Frederick H. Raab

An electromagnetic (EM) system for the location of trapped mine workers at coal-mine (300 m) depths has been developed. The use of such a system in deep mines (1-km depth) requires transmission at extremely low frequencies (ELF) and a reduction in the effective noise level beyond that which can be obtained by acceptable Integration times. Automatic-noise-cancellation (ANC) techniques reduce the effective noise level by combining several received signals that contain correlated noise. Such signals can be obtained either from a remote magnetic antenna or a local electric antenna. During Phase III of this program, real ELF noise data were acquired and used to test the ANC algorithms developed during Phase II. The ELF noise data were obtained from analog recordings made by Develco under another Bureau-of-Mines contract. Digitization was accomplished by an ND converter that was added to a GMRR computer. Phase III tasks Included preparation of software for digitization, computer-computer communication, data processing, and statistical analysis. Useable data were obtained from eleven half-hour tapes containing noise from one axis of the primary antenna and three axes of the remote antenna. The overall average Improvement in SNR was 4.1 dB. However, the average Improvements for the Individual X, Y, and Z axes were 4.2, 11.9, and -1.9 dB, which roughly follow the observed noise power. Nonlinear processing was not effective with this noise.

Jan 2, 1984

By Anthony Iannacchione, Christopher Mark

Residents of Maxwell Hill, a suburb of Beckley, West Virginia, reported from January until March of 1988 a series of earth tremors. The tremors rattled dishes, and the noises associated with tremors were sometimes loud enough to wake people at night. These events were puzzling because Beckley is in an area of low seismic activity. Maxwell Hill is located above abandoned coal mines, though no direct subsidence damage to surface structures has been documented. A research program was initiated to determine whether subsurface ground movements associated with the abandoned mines could be responsible for the seismic activity experienced at the surface. A hypothesis is proposed which states that seismic disturbances can be caused by abandoned mine failure when two conditions are met. First, some instability must exist at the mine level. The most likely cause of instability is the failure of pillars of coal that were left for support at the time of mining. Second, subsurface movements can result in significant seismic activity only when the rock above the mine contains at least one very strong and brittle layer that is prone to fail violently through rupture or fault slip movement. Analysis of the data indicates that both hypothesized conditions for mine-related seismicity appear to have been satisfied in the case of Maxwell Hill. It has therefore been concluded that the earth tremors experienced by Maxwell Hill residents probably are related to the abandoned mines. Analysis of the potential magnitude of these events indicates that they are unlikely to cause significant surface danlage. The probability that future events will disturb the residence of Maxwell Hill should be quite low based on the identified mechanism.

By Allan F. Smith

The influence of hydraulic fluids on spontaneous heating in bituminous coals is determined by measurement of the temperature increases produced in coal-fluid mixtures heated to a temperature sufficient for the initiation of self-heating. Similar tests on as-received coal samples and water-coal mixtures are compared with the results obtained for the various hydraulic fluids. Three of the four coals were sampled from coalbeds known to have a history of spontaneous heating. The data provide a basis for predicting the possible effects in gob or carbonaceous refuse of coal mines.

Jan 1, 1963

By D. Denton, M. Stickney, R. Langston

The National Institute for Occupational Safety and Health and the Stillwater Mining Company worked cooperatively with the Montana Bureau of Mines and Geology to develop a system that would collect seismic data at the Stillwater and East Boulder mines. The purpose was to obtain baseline information on the magnitude and location of mining-induced seismicity to determine if the mines needed multi-channel in-mine monitoring systems. Seismic data recorded at field sites near the mines are being telemetered via FM radio through a series of repeaters to a central recording site where the seismic signals are digitized using an Earthworm data acquisition system. The Earthworm system performs several data analysis tasks in near-real time and places raw seismic data, preliminary hypocenter locations, and magnitudes on a Website within 5 min of a seismic event. Such rapid access to seismic data allows personnel at the Stillwater Mine, Spokane Research Laboratory, and Earthquake Studies Office to evaluate seismic events quickly and respond in ways that may improve the safety of mine personnel underground. Installation of the system also broadened earthquake coverage to south-central Montana, a region previously not covered by the seismograph network.