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By J. S. Tosh

The Federal Bureau of Mines has investigated the equilibrium of the system potassium carbonate (K2C03) potassium bicarbonate (KHCO3) potassium bisulfide (KHS) carbon dioxide (C02) hydrogen sulfide (H2S) water (H20). Partial pressures of hydrogen sulfide, carbon dioxide, and water vapor were measured at 70° to 130° C. over solutions of 20-, 30-, and 40-percent-equivalent potassium carbonate containing from 20 to 3,000 grains of equivalent hydrogen sulfide per gallon of solution. This study was made to obtain equilibrium data for evaluating the feasibility of using solutions of hot potassium carbonate for removing, hydrogen sulfide from gas mixtures. The equilibrium partial pressure of hydrogen sulfide may be correlated with the ratio of the molal concentrations of the solutes (KHC03) (KHS)/ (K2CO3). The relationship is shown graphically for the 30- and 40-percent solutions. Once this ratio is determined, the partial pressure of hydrogen sulfide can be obtained from the curves. The equilibrium data show that effective removal of both carbon dioxide and hydrogen sulfide can be achieved simultaneously with hot solutions of potassium carbonate.

Jan 1, 1960

By Anatol Wojtowicz

This research program was conducted to determine if respirable coal dust emanating from a continuous mining machine can be suppressed more effectively by a high expansion foam than by the water sprays conventionally used. A high expansion foam system was developed and tested on a continuous mining machine under actual operating conditions. The utility of the system was demonstrated. Test results tend to show that foam application is more effective than water sprays in suppressing respirable coal dust. However, because of the extreme variability of the test conditions, scatter in the sampling data, and other factors, not enough data was obtained to form a firm conclusion that foam is more efficient than a water spray in suppressing respirable coal dust. Sufficient statistical data was obtained, however, to indicate that foam is more efficient than water in suppressing total float coal dust.

Jan 1, 1974

By William C. McBee

Prompted by forecasts of a sulfur oversupply, the Bureau of Mines, U.S. Department of the Interior, is conducting research on potentially large-scale uses of this commodity to extend or replace such construction materials as asphalt, cement, and mineral aggregates. Through these efforts, paving materials have been developed in which sulfur replaces up to 50 pct of the asphalt normally present and which can be prepared and placed with existing mixing and paving equipment. Laboratory properties and design methods for this direct mixing process are described along with properties obtained on small-and large-scale field demonstration projects. These properties are compared with those obtained from control materials prepared without sulfur additions. Monitoring for toxic gases during laboratory and commercial mixing and paving operations is discussed also.

Jan 1, 1978

By G. S. Morrow, C. D. Litton

This report presents the results of a U.S. Bureau of Mines evaluation of smoke detectors placed in conveyor belt entries of underground coal mines. The selected mines are located in six different Mine Safety and Health Administration (MSHA) districts, are operated by seven different companies, and use atmospheric monitoring systems from seven different manufacturers. Principal concerns are early detection and warning of fires, reliability of operation, frequency of maintenance, and adaptability of detectors to monitoring systems and the mining environment. The data contained in this report provide for some comparisons between smoke detectors and CO sensors, specifically in the areas of early detection of fires and susceptibility to nuisance alarms due to diesel exhaust contaminants. Finally, recommendations for performance standards, sensitivity tests, detector classification, and maintenance are presented.

Jan 1, 1992

By Sivalingam Jeevan, R. L. McConnell

Ground check monitors may be made in several configurations. Each type has unique characteristics and provides different safety attributes when applied to different mine situations. In this paper, the monitor types are discussed in relation to the mine situations. It is shown that the selection of the monitor type can have a significant effect on the safety of the resistance grounded power system. The options are discussed, and the conclusion is drawn that only one monitor configuration can provide maximum safety. Unfortunately no monitors of this configuration are presently available. In addition, when the monitor capabilities and ground wire configurations are considered as a system, it can be shown that certain configurations will lead to maximum safety. This work was supported by U.S. Bureau of Mines grant G0144138.

Jan 1, 1979

In 2005, a total of 4,490 stone mining operations reported employment to the Mine Safety and Health Administration (MSHA). Stone mines comprised 30.6% of all mining operations. ? Mines producing the primary commodity of limestone (crushed and broken) comprised the largest number of operations (n=2,039; 45.4%). ? Stone mining operations were located in all states and territories except Delaware and North Dakota. ? Of all states, Pennsylvania had the most stone mines (n=379; 8.4%).

Jan 1, 2008

By Manuel Gomez

The Bureau of Mines used data from 31 core samples to develop prediction equations for evaluating chemical and carbonization properties of six seam units in a lignite deposit approximately 2 miles wide and 8 miles long in the Wilcox Formation of central Texas. Statistical response surfaces, based on core analyses, were computed for 14 parameters indicative of lignite quality. These computed surfaces, and their mathematical equations, can be used to predict values of the selected properties of the lignite seams at any desired surface coordinate position between core hole locations. The wide range of application shown by this study indicates that the methods of statistical regression analysis may be useful to evaluate large deposits of lignite or higher rank coal.

Jan 1, 1969

By d&apos, Kathleen J. Amico

THIS SUMMARY appears in Minerals Yearbook volumes I and III, which cover mineral production in the United States, its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, as well as the principal minerals imported into and exported from the United States. The several commodity and area chapters contain further details on production. A summary table comparing world and U .S. mineral production also is included. Mineral production may be measured at any of several stages of extraction and processing. The stage of measurement used in the chapter is normally what is termed ?mine output." It usually refers to minerals in the form in which they are first extracted from the ground, but customarily includes for some minerals the product of auxiliary processing operations at or near mines.

Jan 1, 1965

By D. R. Tesarik, R. W. McKibbin

Material properties affecting slope stability were measured in a large 50-year-old, partially consolidated rockdump located in an active open-pit mine. Field tests included single-ring infiltration and density. In addition, a nuclear depth-moisture gauge was used to measure water content in six stainless-steel-cased drill holes on the crest and an upper bench of the rock dump. Precipitation, evaporation, wind speed and direction, and temperature data were collected at a weather station installed on the dump’s crest. Laboratory tests included particle-size distribution, specific gravity, Atterberg limits, and water content. By measuring material properties of a rock dump presumed to be stable, the safety of miners working on or at the toe of old rock dumps constructed of similar material and located in a similar climate can be assessed.

Jan 1, 1999

By d&apos, Kathleen J. Amico

THIS SUMMARY appears in Minerals Yearbook volumes I and III, which cover mineral production in the United States, its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, as well as the principal minerals imported into and exported from the United States. The several commodity and area chapters contain further details on production. A summary table comparing world and U.S. mineral production also is included. Mineral production may be measured at any of several stages of extraction and processing. The stage of measurement used in the chapter is normally what is termed ?mine output." It usually refers to minerals in the form in which they are first extracted from the ground, but customarily includes for some minerals the product of auxiliary processing operations at or near mines.

Jan 1, 1965

By d&apos, Kathleen J. Amico

THIS SUMMARY appears in Minerals Yearbook volumes I and III, which cover mineral production in the United States, its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, as well as the principal minerals imported into and exported from the United States. The several commodity and area chapters contain further details on production. A summary table comparing world and U.S. mineral production also is included. Mineral production may be measured at any of several stages of extraction and processing. The stage of measurement used in the chapter is normally what is termed "mine output." It usually refers to minerals in the form in which they are first extracted from the ground, but customarily includes for some minerals the product of auxiliary processing operatons at or near mines.

Jan 1, 1963

By C. Stephan, E. Weiss, J. Trackemas, M. Sapko

The National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory (PRL), in collaboration with the Mine Safety and Health Administration (MSHA), the mining industry, and seal manufacturers recently conducted a series of full-scale experiments within the underground experimental mine at PRL’s Lake Lynn Laboratory. The purpose of the experiments was toe valuate the explosion-resistant characteristics of several new seal designs for rapid deployment during mine emergencies. These seals can be deployed in 6 to 10 hr and are capable of with standing explosion overpressures in excess of 140 kPa (20 psi). These novel seal designs use available mine materials, do not require conventional rib hitching, and, most importantly, can substantially reduce exposure time for coal miners during sealing and mine recovery operations.

By McHenry Mosier

A skull breaker has demonstrated its advantages for secondary breaking in a limestone quarry by entirely displacing secondary blasting . It has reduced safety hazards to workmen, increased the number of quarry operating days , and has lowered mining costs by 2.7 cents a ton. It is believed that the application of the skull breaker can be made economically advantageous in the surface mining of other commoditics .

Aug 1, 1948

By McHenry Moiser

"SUMMARY This mine, which was discovered in 1846, was active in the 1850's, in the 1870's, and again in 1883. Since this last date, it has been idle. Two parallel bed-veins in lower Silurian limestone, about 50 feet apart, strike N. 70° E. and dip 70° NW. The north vein had an average width of 12 feet to a depth of 50 feet, where it was barren. The south vein had an average width of 16 feet to a depth of 75 feet; on the 110-foot level, although well-defined it carried little or no values. The zinc content of the ore was as high as 12 percent, and some lead and silver were associated with it. A reduction plant for production of spelter and zinc oxide was constructed at the mine. The only available record of production is for 1873 to 1876, inclusive, when 357 tons of smelter was shipped. The mine is caved and inaccessible, and nothing now remains of the treatment plant.Four holes totaling 1,046 feet wore diamond-drilled to probe for extensions of the ore in depth. Core recovery was about 85 percent. No samples were taken for analysis.INTRODUCTION AND ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. The policy of the Bureau is to publish the facts devel¬oped by each project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, does the actual investigative work, and prepares the final report. The Metallurgical Branch, Oliver C. Ralston, chief, analyzes samples and makes beneficiation tests.The deposit was examined in 1944 by C. B. White, mining engineer of the Bureau of Minos. Diamond-drilling was under the immediate supervision of McHenry Mosier. 2/ The diamond-drill cores were logged by Arnold Brokaw, geologist, Federal Geological Survey, and 'wore filed in the core library of the Bureau of Mines, Mount Weather, Va."

Jun 1, 1948

By Wesley A. Grosh

The Vest nickel prospect, in Floyd County, Va., was discovered about 25 years ago. Limited exploration of the deposit had indicated some appreciable nickel mineralization in the sulfide ore. The property was examined on March 9, 1943, by an engineer of the Bureau of Mines in company with C. W. Vest, owner of the property. A limited exploration program was recommended. Two holes totaling 320 feet were diamond-drilled in January 1944. Drilling indicated the sulfides are sparsely disseminated. The only nickel values of interest were at the old prospect shaft.

Jan 1, 1949

By Robert F. Randolph

Research on improving haulage truck safety, started by the U.S. Bureau of Mines, is being continued by its successors. This paper reports the orientation of the renewed research efforts, beginning with an update on accident data analysis, the role of multiple causes in these accidents, and the search for practical methods for addressing the most important causes. Fatal haulage accidents most often involve loss of control or collisions caused by a variety of factors. Lost-time injuries most often involve sprains or strains to the back or multiple body areas, which can often be attributed to rough roads and the shocks of loading and unloading. Research to reduce these accidents includes improved warning systems, shock isolation for drivers, encouraging seatbelt usage, and general improvements to system and task design.

Jan 1, 2000

By R. Karl Zipf

The sudden, violent collapse of large areas of room-and-pillar mines poses a special hazard for miners and mine operators. This type of failure, termed a 'cascading pillar failure' (CPF), occurs when one pillar in a mine layout fails, transferring its load to neighbouring pillars, which causes them to fail, and so forth. Recent examples of this kind of failure in coal, metal and nonmetal mines in the U.S.A. are documented. Mining engineers can limit the danger presented by these failures through improved mine design practices. Whether failure occurs in a slow, non-violent manner or in a rapid, violent manner is governed by the local mine stiffness stability criterion. This stability criterion is used as the basis for three design approaches to control cascading pillar failure in room-and-pillar mines-the containment approach, the prevention approach and the full extraction mining approach. These design approaches are illustrated with practical examples for coal mining at shallow depth. Cascading pillar failure {CPF) in room-and-pillar mines can go by many other names, such as `progressive pillar failure', `massive pillar collapse', 'domino-type failure' or 'pillar run'. In this kind of failure when one pillar collapses the load that it carried transfers rapidly to its neighbours, causing them to fail, and so forth. This failure mechanism can lead to the rapid collapse of very large mine areas. In mild cases only a few tens of pillars might fail; in extreme cases, however, hundreds, even thousands, of pillars can fail. CPF can have catastrophic effects on a mine, and sometimes these effects pose a greater risk to health and safety than the underlying ground-control problem. Usually, the CPF induces a devastating air blast as a consequence of the displacement of air from the collapse area. An air blast can disrupt the ventilation system totally by destroying ventilation stoppings, seals and fan housings. Flying debris can seriously injure or kill mining personnel. The CPF might also fracture a large volume of rock in the pillars and immediate roof and floor. In coal mines and certain other mines this can lead to the sudden release of large quantities of methane gas into the mine atmosphere; a methane explosion might result from the CPF. CPF is at the far end of the spectrum of unstable pillar failure. At the other end are slow `squeezes' that develop over days to weeks and, because of their slow progress, do not pose an immediate danger to mining personnel. There is ample warning time for men and machinery to get out of the way of the failure. In a CPF, however, the failure progresses so rapidly that men and equipment cannot be evacuated in time. Significant seismic energy is released as a consequence of the rapid failure and collapse. CPF should not be confused, however, with coal-mine bumps and rockbursts. In some cases the damage can appear similar, but the underlying mechanics are completely different. As will he shown later, the mechanics of CPF depend on the applied vertical stress and the post-failure, i.e. strain-softening, behaviour of the pillars. In a CPF pillars shed their applied load rapidly and have very little residual strength after failure. The collapse itself may release significant seismic energy, but otherwise the mine is seismically quiet. Alter a CPF the openings in the affected mine workings have usually closed completely. In contrast, coal-mine bumps and rockbursts occur in seismically active mines. Research has shown that coal-mine bumps and rockbursts are seismic events induced by mining that damage underground mine workings. Bumps and bursts are thus a subset of a much larger set of mining-induced seismic events.[ Only some of these seismic events damage mine workings; fortunately, most do not. The mechanisms by which a mining-induced seismic event can lead to a damaging coal-mine bump or rockburst is still a significant research area.2 After a bump or rockhursr the affected mine workings may or may not be completely closed. For example, in the coal-mine bump described by Soler and co-workers2 the mine workings remained open even though the pillars were destroyed during the bump event. Because CPF differs from a coal-mine bump or rockburst, the design approaches to control their occurrence also differ. The design recommendations developed here apply to CPF and not to bump- or burst-prone mines. Cascading pillar failure examples Unfortunately, CPF has occurred in room-and-pillar coal, metal and non-metal mines. The most infamous example is the Coalbrooke colliery in South Africa, where 437 miners perished where [si >1 3at1ttsumsus7car kky vArtMixiL7i nesafr tramwsamn ures] on 21 January, 1960.1 Table I summarizes the mining dimensions of 13 examples of rapid pillar collapse in U.S. coal mines. All occurred during the 1980s and 1990s, and all happened suddenly or without significant warning. Most resulted in air blasts and damage to the ventilation system. Table 2 gives the mining dimensions of six room-and-pillar metal and non-metal mines in the U.S.A. where failure occurred in all probability by the CPF mechanism. The collapse areas can be huge. Fortunately, some of these failures gave advance warning. At the lead-zinc mine slabbing from pillars and roof falls began four weeks prior to the main collapse.3 At the copper mine considerable rock noise and smaller failures preceded the main collapse by five days.5 At the copper-silver mine it is not known if nature provided a warning.6 Evidently, the trona mine collapsed without warning.7,8 Rock noise and other failure warnings preceded the silica mine collapse by three weeks. v The presence or absence of warnings at the salt mint is not known. to Most of these collapses induced a substantial air blast; damage to the ventilation systems was limited, however, to bent airdoors and a few downed stoppings, except at the trona mine where extensive damage to the ventilation system resulted.

By RV. Ramanl, KV. K. Prasad, M. Swaminathan

The objective of the research in this project is to develop a knowledge based expert system for aiding the planning of mine ventilation systems. This system focuses on mine ventilation system design from a coal mine dust control standpoint. It is recognized that mine ventilation system design is an engineering problem involving not only rote numerical calculations to solve the pressure quantity problem but also substantial judgement and expertise to analyze a problem situation and Interpret the results of an algorithmic program. The thrust of this project is to i) extract this knowledge from public domain sources and recognized experts in industry, government and academia, 11) represent this knowledge in the form of IF ... TI-IEN rules in an expert system (ES) and 111) interface the developed expert system with a mine ventilation network analysis program vis. PSUMVS (Pensylvania State University Mine Ventilation Simulator). By providing the numerical computing and qualitative reasoning aspects of mine ventilation system design in a single Integrated system, better quality decision support will be made available to apprentice users.

Jan 1, 1988

By Oliver Bowles

The mineral asbestos, because of its unique fibrous character, is allied to cotton and wool but has the advantage of heat and fire resistance; therefore, it supplies many industrial needs for which no substitutes are yet available. This report covers the essential features of the asbestos industry, including occurrence, production, mining, milling, utilization, international trade, and marketing. The United States leads all countries in the manufacture of asbestos products, but domestic sources furnish only a small fraction of the raw material required. As the United States is dependent to so great an extent on foreign supplies of raw materials, the bulletin deals at length with the asbestos industry in foreign lands. Several reports now available deal with the industry in individual countries. Among them are Chrysotile Asbestos in Canada, by J. G. Ross; Asbestos in the Union of South Africa, by A. L. Hall; and a series of articles on the Russian industry, by Walter A. Ru Keyser. These have been drawn upon freely, and full acknowledgment is hereby made for the helpful information thus secured. The file of the magazine Asbestos also has furnished many valuable data touching all phases of the industry. Many other books and articles listed in the bibliography at the end of this bulletin have been utilized and have been supplemented by the author's intimate acquaintance with the industry for about 20 years. The intent is to present a concise, world-wide, historical, technical, and economic treatment of the asbestos industry.

Jan 1, 1937

Consumption and intensity of use trends for 12 metals, by industrial end use, were estimated for 1972 through 1982 by the Bureau of Mines and U.S. Department of Commerce. The trends were then forecast through 1993 using standard statistical methods. The intensity of use measure selected is the quantity of metal consumed per constant dollar output of a specific industrial sector. The metals studied were aluminum, chromium, cobalt, copper, lead, manganese, nickel, the platinum-group metals, tin, titanium, tungsten, and zinc. Average annual growth rates for the following 4 of the 12 metals increased from 1972 to 1982 as follows: aluminum, 1.00%; platinum-group metals (consisting of platinum, palladium, and iridium), 8.83%; titanium, 7.82%; and tungsten, 6.09%. Consumption for the remaining eight metals decreased at average annual rates ranging from 0.58% (copper) to 5.37% (manganese).

Jan 1, 1986