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By E. Chin

The Asia and the Pacific region has large mineral resources of antimony, barite, bauxite, bismuth, copper, fluorspar, gold, graphite, iron ore, magnesite, mica, rare earths, salt, talc and pyrophyllite, titanium, zinc, and zirconium. The region overall lacks large resources of oil and natural gas, but it has large resources of anthracite and bituminous coal. In terms of exploitation, many minerals, metals, and fuel are produced in significant quantities in the Asia and the Pacific region as shown in table 1. Collectively, the area accounts for a substantial amount of the world production of antimony, barite, bauxite, fluorspar, gold, graphite, ilmenite and rutile, iodine, iron ore, lead, magnesite, manganese, nickel, salt, tin, tungsten, and zinc. Total coal production of the region exceeds 1.6 billion metric tons. The production of bituminous coal accounts for more than 80 % of the total output. China is the region's largest coal producer, with an output of almost 1.1 billion tons. Other major producers are Australia and India. The combined production by Australia, China, and India is more than 1.5 billion tons or 93 % of the area's output. The remainder of the coal output in the region comes from Afghanistan, Cambodia, Indonesia, Japan, the Korean peninsula, Malaysia, Mongolia, New Zealand, Pakistan, the Philippines, and Taiwan. The production of crude oil throughout the Asia and Pacific region is close to 2.4 billion barrels. China and Indonesia together account for 67 % of the total output. The remainder of the output is primarily from Australia, Brunei, India, and Malaysia. Indonesia is the largest producer of natural gas in the region with an output of close to 58 billion cubic meters, followed by Malaysia and Australia with 23 and 22 billion cubic meters, respectively. Other producers in the region of lesser stature by output include Brunei, China, India, and Pakistan.

Jan 1, 1993

By G. L. Oldright

The data presented in this paper were collected at the smelter of the Consolidated Mining & Smelting Co. of Canada, Ltd., Trail (Tadanac), British Columbia. Many thanks are due to S. G. Blaylock, vice president and general manager, James Buchanan, smelter superintendent, and George Murray, assistant smelter superintendent, for their broad general policy in permitting these data to be taken and published. life are also grateful for the help given by the staff members stated in Paper XI, Report of Investigations Acknowledgment is given several excerpts from experiments by F. E. Lee, head of the research staff. INTRODUCTION The past reputation of zinc as an ingredient in lead blast furnace slags has been bad. Zinc is thought of as a cause of accretions in the shaft of the blast furnace, of hot tops, of the formation of "zinc mush" in the crucible and forehearth, of lead-rich slags, of viscous slags, and. of low capacity in smelting.

Jan 1, 1934

This work examined the feasibility of in-mine coal preparation in two phases. Phase I included a survey of previous investigations and a preliminary analysis of the economic and technical feasibility on a selection of representative sites and degrees of cleaning. The contract was terminated at the end of Phase I. The preliminary analysis determined that in-mine preparation systems can be applied using currently available technology. The most likely mines for application will have shaft or slope access and be deeper than 500 feet. The refuse disposal systems technically feasible are (1) pneumatic placement of coarse refuse in room and pillar panels or longwall faces, (2) mechanical placement of coarse and fine fractions in room and pillar panels, and (3) hydraulic placement of fine fractions in room and pillar panels. The economic feasibility is much more dependent on the refuse disposal-system than on the preparation system. It is estimated that the capital cost of an in-mine preparation and disposal system would be $6.00 per clean ton and the operating cost would be $1.24 per clean ton for a 1 million clean ton per year mine.

Jan 1, 1982

Multiple-seam interactions are a major ground control hazard in many U.S. underground coal mines. In some U.S. coalfields, particularly in central Appalachia and the West, the majority of today’s mines are operating above and/or beneath previously mined seams. The effects of multiple-seam interactions can include roof falls, rib spalling, and floor heave. These can seriously disrupt mining operations and threaten the safety of miners. In early 2006, a West Virginia coal miner was killed by rib roll that occurred in a high-stress zone beneath a remnant structure in an overlying mine. Fortunately, not every multiple-seam situation results in hazardous conditions. Indeed, the vast majority do not. For the past several years, the National Institute for Occupational Safety and Health has been conducting research to develop better techniques for predicting the location and severity of multiple-seam interactions. During this investigation, more than 50 mines were visited across the U.S. coalfields. Nearly 300 case histories were collected and analyzed using multivariate statistical techniques. The study also employed the numerical model LaM2D to estimate the multiple-seam stress, the Analysis of Longwall Pillar Stability (ALPS) and the Analysis of Retreat Mining Pillar Stability (ARMPS) programs to determine pillar stability factors (SFs), and the Coal Mine Roof Rating to measure roof quality. The study focused on the two most common types of multiple-seam interactions: • Undermining, where stress concentrations caused by previous full extraction in an overlying seam is the main concern; and • Overmining, where previous full extraction in an underlying seam can result in stress concentrations and rock damage from subsidence. The study confirmed that overmining is much more difficult than undermining, and isolated remnant pillars cause more problems than gob-solid boundaries. For the first time, however, it was possible to quantify these effects in terms of the equivalent thickness of interburden needed to compensate for them. The study also found that pillar design is a critical component of multiple-seam mine planning. Many of the failed cases involved pillars whose SF seemed inadequate once the multiple-seam stresses were accounted for. Weaker roof was also found to significantly increase the risk of multiple-seam interactions. The most important result of the study is an equation that predicts the critical thickness of the interburden required to minimize the likelihood of a multiple-seam interaction. This equation was incorporated into a step-by-step methodology that allows mine planners to evaluate each potential interaction and take steps to reduce the risk of ground control failure. Such measures could include installing cable bolts or other supplemental support, increasing the pillar size, or changing the mine layout to avoid the remnant structure entirely. These Proceedings also contain several previously published papers that cover other facets of multiple-seam mining research. Two papers describe the LaModel family of software developed by Professor Keith A. Heasley of West Virginia University. The LaModel programs were designed for calculating the stresses and displacements in coal mines or other thin, tabular seams in layered media. The original three-dimensional version of LaModel is essential for detailed analyses of complex multiple-seam scenarios. LaM2D, by contrast, implements a simplified two-dimensional model that is suitable for quick approximations of the multiple-seam stresses and strains. Three additional papers in these Proceedings describe the extensive multiple-seam experience of the Harris Mine, examples of extreme multiple-seam mining from the central Appalachian coalfields, and longwall mine experiences in Pennsylvania, West Virginia, and Utah. The final paper reports on a numerical modeling study that provided some insight into the mechanics of multiple-seam mining.

Jan 5, 2007

By Allen McComas, Frank Chase, Phyllip Worley

Longwall mining has gained the reputation as being the safest extraction method in underground coal mines. However, one of the most difficult tasks associated with longwall mining is moving the face once a panel is completed. Based on Mine Safety and Health Administration (MSHA) fatality reports since 1996, longwall face recovery operations have claimed the lives of 5 U.S. miners and have resulted in numerous injuries. Recovery operations can be hazardous because they involve moving large pieces of equipment in very confined spaces. They are also conducted in highly stressed ground conditions due to front abutment loads generated by panel extraction. Shield removal is the most hazardous operation during face recovery because miners are constantly exposed to the unpredictable gob edge. To protect the miners, one or more walking shields, cribbing and/or other supplemental roof and standing supports are typically employed as breaker line supports as each shield is removed. At the Harris No. 1 Mine in southern WV, mobile roof supports (MRS’s) have been used in lieu of traditional walking shields on 17 face moves since 1997. MRS’s are shield-like support units mounted on crawler tracks and are commonly used during room-and-pillar retreat mining operations. For longwall recovery, the two biggest advantages that MRS’s have over traditional walking shields are that they are remotely controlled and are highly maneuverable. MRS’s have contributed to safer shield recovery and shorter move times at the Harris No. 1 Mine. This paper will address both the safety and the operational issues associated with MRS usage during shield recovery. It will also discuss new developments, including the use of the inherently safer battery powered MRS’s, which have been recently certified by the Mine Safety and Health Administration.

By Robert V. Berryhill

Reconnaissance studies of beach deposits along approximately 220 miles of the shoreline of Bristol Bay, Alaska, were made to determine if more detailed investigations were warranted. In addition to preliminary mapping of the deposits, samples were obtained from auger borings spaced at 1-mile intervals in key areas; shovel samples were collected to supplement the borings. Most samples were roughly concentrated in the field; magnetic separation tests, petrographic analyses, and determinations for radiometric equivalent uranium, gold, platinum, iron, and titanium were made in the Bureau of Mines laboratory at Juneau, Alaska. Spot samples from some beaches along the shores of the Alaska Peninsula indicate small deposits containing up to 10 percent recoverable titaniferous magnetite; some larger deposits were indicated to contain from 1 to 2 percent total heavy metal, principally as titaniferous magnetite. Significant amounts of other commercial minerals were not detected.

Jan 1, 1963

By Larry G. Stolarczyk

Jan 1, 1980

By David S. Yantek

Miners in underground coal mines experience prolonged exposure to high noise levels, often with A-weighted sound levels in excess of 90 dB. Field tests have shown that the continuous miner conveyor is a dominant noise source. This paper will identify the most significant noise-radiating surfaces on the continuous miner tail section using vibration levels and surface areas to estimate the sound power levels of each surface. In addition, using five test cases, this study will examine the effects of three engineering noise controls on the surface-averaged vibration levels and average sound levels measured with four microphones located two meters from the tail section. The noise-radiating surfaces of the conveyor’s tail section include the top and bottom decks, the sideboards, and the flex plates. Emphasis is placed on the changes in the estimated sound power levels in the 500 – 2500 Hz 1/3-octave bands since this frequency range accounts for 80-85% of the sound energy near the tail section. The results show that the bottom deck is the most significant noise radiator for the untreated miner. Installing a coated bottom deck reduces the estimated sound power level radiated from the bottom deck by 11 dB and the average sound level by 2 dB. Using a coated tail roller results in reductions of the estimated sound power levels for individual components from 1 to 4 dBand reduces the average sound level by 2 dB. Coating the slide plate has little effect on both the estimated radiated sound power levels and the average sound level. The test results indicate that modifications that reduce flex plate vibration and reduce energy transfer from the tail roller into the tail section will be effective in reducing noise when combined with a coated tail roller and coated return deck.

By Paul S. Goodman

This report examines the effectiveness of bonus plans in the coal industry. The analysis uses theoretical, literature review and empirical approaches to determine the impact of bonus plans on safety and productivity in underground coal mines. The basic finding is that the modal bonus plan in underground coal mining does not have a major impact on productivity and safety indicators. The design of the plan, or organizational factors, and the process of introducing the plan all contribute to its relative ineffectiveness. Strategies and options for designing effective plans are presented.

Jan 1, 1987

By Ernest A. Curth

Statistics For 1956-66 show that mine transportation accidents accounted for 19 percent of fatalities in bituminous coal mines, second only to roof deficiencies as a cause of death. Productivity per man-shift increased from 10.2 tons in 1956 to 18.4 tons in 1966, but the fatalities per million man- hours of exposure also increased from 0.19 to 0.21 during that same period, indicating that transportation hazards still persist. Consequently, the Bureau of Mines reviewed the transportation fatalities that occurred in bituminous coal mines during 1956-66. The data were processed by computer to find what constitute hazardous conditions and unsafe actions as well as to correlate occupation and age of victims, transportation type, and mine production. Environmental factors and equipment defects which create hazards, as well as unsafe actions of personnel, were determined for each type of mine transportation: Track haulage, mobile nonrail haulage, conveyors, hoists, automotive operations, and front -end loaders, and for transfer stations (loading points, slope and shaft bottoms, surface transfers) and railroad yards. Man-trip accidents, a group with a catastrophe potential, also were analyzed. The basic design and operational features of each transportation type were outlined and procedures considered safe in the light of accident experience were suggested. Findings show that unsafe actions of personnel and hazards created by environmental deficiencies or equipment malfunctions contribute equally in causing transportation accidents. Accordingly efforts should be directed toward improving working conditions, equipment maintenance, and education and training of employees. The trend is toward using safer modes of transportation, notably conveyors. More attention should be given to track haulage operation, railroad yards, and nondestructive field testing of materials.

Jan 1, 1971

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Jan 1, 2008

By J. C. Edwards

A series of four coal combustion experiments (I)' was conducted at the National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory in the Safety Research Coal Mine to evaluate the response of optical and ionization smoke and CO sensors to a small 0.61 m square smoldering coal fire which transitions to flaming combustion in the presence of diesel emissions. With the increased utilization of diesel engines in underground coal mines, it is important to be able to discriminate fire products-of-combustion (POC) from diesel emissions. One proposed method to accomplish this is the deployment and interpretation of multiple sensors.

Jan 1, 2010

By M. A. Trevits, J. E. Urosek, A. C. Smith, M. P. Valoski

Unlike other types of mining accidents, where an incident generally involves only a few workers, the danger of a mine fire extends to every person working in the underground environment. Mine fires can trap or kill those working underground by blocking avenues of escape and rapidly creating heat, asphyxiating gases and toxic fire products that can quickly spread throughout the mine. The National Institute for Occupational Safety and Health (NIOSH), in partnership with the Mine Safety and Health Administration (MSHA), is conducting research to test, evaluate and improve or modify coal mine fire-fighting strategies and methodologies through large-scale tests. Because wood is the second most abundant fuel available during a coal mine fire, it was decided that a series of large-scale wood crib fire tests was needed to measure the products of combustion and to observe the capability of commonly available direct application fire suppression equipment, namely, fire extinguishers, water and gas-enhanced foam. This paper discusses the wood crib fire tests, provides insight into the products of combustion and describes observations made during the application of the fire suppression agents.1

By A. George Stern

In the examination of bentonitic clay suspensions used for oil-well drilling fluids3/ (and for other purposes, such as a core binder for foundry sand) it is important to have comparative tests for evaluating them. A satisfactory clay for these and other purposes should 'rave the property of forming what is commonly called a "gel," but the measurement of this property has been a real problem. To date the solution has not been satisfactory, and some of the difficulties are considered in, this, paper, which describes a simple form of instrument (identified as an eykometer) for measuring the yield point under hydrostatic conditions of non-Newtonian clay suspensions, including those muds that are thixotropic. An oil-well drilling mud serves several functions, many of which depend on the "gel" characteristics of the mud. Among the more important functions are: (a) To plaster the sides of the hole to prevent caving of the walls; (b) to prevent the loss of the circulating fluid out of the hole by seepage; (c) to carry sand and cuttings out of the hole to the surface as they are formed by the rotary drill; and (d) when circulation of the fluid stops for shut-down or other unavoidable cause, to hold the cuttings in suspension by the setting up of the gel, thereby avoiding the difficulties that result when these cuttings are allowed to fall through the fluid and pack at the bottom of the hole.

Jan 1, 1940

By Henry Kreisinger, J. F. Barkley

This book is one of a series of publications being issued by the Bureau of Mines for the purpose of disseminating information in regard to the methods by which the fuels in this' country may be used most efficiently. A knowledge of the temperature of the gases in boiler settings and in other commercial apparatus using heat tends to develop improved designs of apparatus and better methods of operation, thus reducing waste of fuel. The following pages present, for the benefit of those designing, operating, and testing such apparatus, information as to the accuracy of temperature measurements made under certain conditions and the corrections that can be safely applied.

Jan 1, 1918

By Svend [Bue] Rondum

The final report contains a summary of the work performed under this contract, In addition to the report itself, other products were derived from this effort. Several hardware items were prototyped for use with underground belt conveyors, and a manual for installation and maintenance procedures was developed and published under separate cover. Recommendations have been included for implementation of the tools and the manual or, an industry-wide basis.

Jan 1, 1982

By Joseph B. Cummings

"INTRODUCTION The property was first examined by an engineer 3/ of the Bureau of lanes in December 1942 and was later investigated by the sane engineer in January and February 1943. Prominent outcrops and underground exposures of high-grade iron ore, together with mention of sizable intersections of hematite in logs of four widely scattered churn—drill holes, indicated the possible occurrence of a substantial tonnage of iron ore at this old copper producer.From March to May 1943, detailed topographic and geologic mapping of the property was done by the Federal Bureau of Mines, the Federal Geological Survey, and the Arizona Bureau of Mines.Funds were allotted for exploration of the property by churn and diamond drilling. This work was started in December 1943 and completed in June 1944.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Nines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts, developed by each exploratory project as soon as practicable after its conclusion. The Mining Drench, Lowell B. Moon, Chief, conducts preliminary exmination, performs the actual exploratory work, and prepares the final report, The Metallurgical Branch, P. G. Knickerbocker, Chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision Dr. R. S. Dean, Assistant Director."

Dec 1, 1946

This section of Minerals and Materials analyzes the following three factors affecting the recent performance of the U.S. and world mineral industries: 1) the health of the U.S. and world economies, 2) the level of interest rates and 3) the performance of productivity in both the U.S. mineral industry and the general economy. While these indicators do not exhaust the possible critical factors, they represent an initial attempt to probe some of the considerations underlying the performance of the U.S. minerals and materials industry. The U.S. and World Economies It is essential to analyze the state of the U.S. and world economy because the demand for minerals and materials is a derived demand; that is, since minerals and materials are used in the productive process, the demand for them is a direct function of the demand for the finished products of which they are a basic input. Thus, the demand for minerals and materials is directly affected by changes in present and planned consumption and investment expenditures. The past two issues of this publication have highlighted the generally discouraging performance of the national and inter-national economies. Briefly, the world economy is in the third year of the first long recession in recent history where inflation rates have remained above 5 percent. With many countries either unable or unwilling to support domestic spending while inflation continues, there has been a growing tendency to institute trade-restrictive policies to support domestic demand. The resulting weakened demand conditions in exporting nations have had a direct effect on the mineral industry.

Jan 1, 1982

By R. W. Stahl

Burning coal-mine refuse banks were surveyed in 15 States. The following characteristics were tabulated for 495 hanks: County; name, population, and distance of nearest town; size and status of bank; status and stage of fire; and topography. Ways of controlling fires were reviewed, the compacting and sealing method proving most satisfactory. Means for preventing refuse-bank fires by proper construction of banks are described.

Jan 1, 1964

By Steven K. Ruggieri

This report describes the operation and maintenance of the Mobile Inert Gas Generator for use in the Remote Sealing System for fighting underground coal mine fires. Seals are emplaced in mine passageways between the fire zone and the rest of the mine isolating the fire zone from the mine. The seals consist of fly ash that has been pneumatically conveyed via inert gas through a borehole connecting the surface and the passageway, Inert gas is used as the fly ash seal transport medium (instead of fresh air) since the introduction of large volumes of fresh air in the vicinity of the fire zone would be undesirable. The inert gas generation equipment is mounted on two flatbed trailers, the "hot" trailer and the "cold" trailer. The hot trailer contains the combustion and cooling equipment. The cold trailer contains the moisture removal and compression equipment necessary to convey the fly ash. The system is self-sufficient and requires only fuel and fly ash deliveries. The Inert Gas Generator has been thoroughly performance tested and has been operated in the field for approximately 200 hr. The system was employed in the demonstration of the entire Remote Mine Sealing System at the Jenney Mine in the Fall of 1978. The system is currently available for fighting any future underground coal mine fires.

Jan 1, 1980