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By Stephen C. Tadolini, Gabriel S. Esterhuizen, Anthony T. Iannacchione

A Major Hazard Risk Assessment (MHRA) was developed in Australia after a series of mine disasters in the 1990’s. A MHRA is used to help prevent major hazards, i.e. fire, explosion, wind-blast, outbursts, spontaneous combustion, roof instability and chemical and hazardous substances, from injuring miners. A MHRA is a structured process that identifies the characteristics of major hazards, assesses and ranks the risk they present, and evaluates engineering and administrative controls to mitigate them. These controls typically consists of a broad spectrum of prevention, monitoring, first response, and emergency response techniques and helps to move an operation from a reactive to a proactive approach towards safety. This paper documents a MHRA performed at an underground mine where strata instabilities and fire hazards may threaten the condition of its escapeways. The objective of this MHRA is to 1) identify what hazards could affect the egress through the mine’s escapeways, 2) determine what unwanted events pose the greatest threat for the mine, and 3) recommend a plan to prevent or recover from the potential disruption of egress through the escapeway. The plan provides information on the key existing controls that should be monitored and audited, and makes recommendation of new potential controls to further reduce related risks. By documenting the use of MHRA to this specific ground control issue, this paper provides a framework for others to judge the merits of this approach and to help design and perform these activities.

By Paul M. Tyler

One of the best present-day yardsticks of the material welfare of a nation is its consumption of minerals, The United States, with only 7 percent of the world population, consumes 45 percent of the world wealth, pays the highest real wages, has the shortest working hours, and numbers the largest percentages of home owners among its population, and at the same time its per-capita consumption of minerals is far greater than that of any other nation. In 1937, British India, with roughly twice the population of the United States, used less than 2 percent as much lead, 4 percent as muck zinc, and 13 percent as much copper; even in Europe, which has three times our population and where war preparations have greatly expanded the normal needs of peaceful industries, the aggregate consumption of metals and industrial minerals other than lignite is less than the total for the United States alone. The march of civilization passed from the Stone Age to the Bronze Age before the dawn of history. It may be questioned whether man or monkey first threw stones at an enemy, but only man could have fashioned rough stones into weapons. Eoliths rudely shaped by apelike men are believed by archaeologists to have antedated by hundreds of thousands of years the existence of our own human ancestors. The primitive people that followed the retreating Ice Cap northward in early quaternary period - at least a million years ago - were fairly adept in the shaping of flints and even used a little copper. The Bronze Age, so-called, superseded the Stone Age when, around 8,000 B. C., the news spread that chunk s of natural copper could be pounded into better weapons or cutting implements than ever could be made by chipping stones. The Bronze Age gave place to the Iron Age about 1,000 B, C., and though students of modern history may speak of the Coal Age, the Petroleum Age, and the Automobile Age, and so on, these ages have all been crowded into a brief century and a half. The truth is that we still are in the Iron Age, unless perhaps we choose to call it the Age of Many Metals.

Jan 1, 1940

By J. L. Kohler

Component failures in the electrical control circuits of mining machines account for a large percentage of the total downtime of the machine, Once a failure has occurred it is always a tedious and usually a time-consuming task to locate the failed component. Moreover, the pressure to quickly locate the cause of a delay can lead to compromises in safety. Thus an onboard diagnostic system, essential for an automated machine, would be a very useful addition to existing machines. This report details U.S. Bureau of Mines development of a generic procedure for synthesizing diagnostic systems for electrical-control-circuit failures in mining machinery. A continuous mining machine is used as the testbed to illustrate the application of the developed methodology. Substantive differences among mining machine control circuits made it impossible to achieve a generic diagnostic system, but a generic approach for the synthesis of the diagnostic system was possible. As the research progressed, it became apparent that an algorithmic approach was better than an expert-system-based implementation. A prototype system was constructed and used to evaluate the diagnostic system. Prototype implementation issues are also examined.

Jan 1, 2010

By Albert E. Long

During the summer and fall of 1948 the Bureau of Mines, in cooperation with the U. S. Geological Survey, conducted 6xperiments in diamond core drilling in the Phosphoria formation in southeastern Idaho and southwestern Wyoming. Nearly all of the diamond core drilling in the Phosphoria formation has been done by mining companies interested in finding and developing phosphate-bearing beds amenable to stripping. The recovery of sludge; and enough core (usually 30 to 60 percent) to identify certain marker beds produced by current drilling practices meets both the primary requirement of mining companies in determining depth of overburden and their secondary need to determine the phosphate content of relatively thick minable units whose general composition and nature are already fairly well established.

Jan 1, 1949

By W. A. McKinney

Bureau of Mines Research has demonstrated that it is technically feasible to segregate oxidized copper ores by use of a direct-fired, refractory-lined rotary kiln. Previously, the segregation process had been effected only in much more complicated indirect-fired, stainless steel kilns, The method comprises heating crushed ore premixed with small quantities of salt and carbonaceous material, such as coke, to about 830° C to produce copper as fine flake and metallic films on the surface of the coke particles. After grinding of the cooled furnace calcines, the copper is recovered by conventional flotation. During direct-fired segregation it was necessary to closely control the air-gas mixture in the burner. Good copper recoveries were obtained only when adding air in the limited range of 1.15 to 1.2 times the theoretical amount required for combustion of the natural gas. Batch trials of the new technique on quartzite-, limestone-, sandstone-, and limonite-type oxidized copper ores containing from 1.4 to 6.2 percent copper yielded flotation concentrates containing from 3.7 to 45 percent copper, representing 84 to 95 percent recoveries. Analyses of the furnace gases showed that loss of copper by volatilization was negligible. The preliminary direct-firing segregation studies were complemented by continuous runs on the quartzite ore, containing 1.4 percent copper, in an integrated segregation-flotation pilot plant having a 60 pound-per-hour capacity. In a typical test, 84 percent of the copper was recovered in a cleaner flotation product containing 25 percent copper. The study will be continued to further delineate the conditions for good segregation as effective use of standard ceramic-lined kilns will render the process more attractive from a commercial standpoint.

Jan 1, 1963

By Howard E. Rollman

South Central United States, an area including Arkansas, Kansas, Louisiana, Mississippi, Missouri, Oklahoma, and Texas, is a net exporter of refractories. Nearly $45 million of these materials was shipped in 1954 from plants in the area, compared with area consumption of $18.5 million. About 88 percent of all refractories production is concentrated in Missouri. The prevalent consumption pattern, however, is one of localized shortages. For example, although Texas uses more than half of the refractories consumed in the South Central United States, production of refractories in Texas is relatively small. Also, the apparent self-sufficiency of the area is in terms of value produced rather than in terms of products consumed. Nearly all of the $6,425,000 nonclay refractories consumed in the area were shipped from other States. Local resources possibly could be developed for making refractories to serve markets that currently are being supplied from outside the area. Since other industries are growing rapidly in the area, the market for refractories is expected to continue to grow--more rapidly than the national market. The Missouri refractories industry is economically important nationally. Nearly one-fourth of the clay refractories produced in the United States are made in Missouri. Moreover, Missouri produces most of the higher grade clay refractories, about 62 percent of the high-alumina refractories, and 85 percent of the superduty refractories. The competitive position of the Missouri refractories industry is strong. The national market for clay refractories and the market in the South Central United States are expected to continue to grow. The ratio of net income to the value of refractories shipped in Missouri is larger than the national average.

Jan 1, 1960

By Albert L. Toenges

EARLY in 1949, the Economic Cooperation Administration requested the Bureau of Mines to assign a coal-mining engineer to study milling conditions in Greek lignite mines; to make recommendations for the introduction of methods and practices that should increase production and decrease the cost of mining; and, from the results of a geological reconnaissance by geologists of the United States Geological Survey, to suggest plans for the development of mines to supply fuel for a thermal power plant, Albert L. Toenges was assigned to this investigation and arrived in Athens, Greece, March 15, 1949. The study of mining operations and the geological reconnaissance (which was made by W. G. Pierce and X. M. Denson, geologists, United States Geological Survey) Were conducted concurrently. The Geological Survey will publish the results of its investigation separately. Washability studies of lignites from Aliveri and Kimi were made at the Central Experiment Station of the Bureau of -Mines, Pittsburgh, Pa. The lignite fields mentioned in this bulletin are shown in figure 1.

Jan 1, 1951

By Frederick W. Lee

List of contributing editors of Geophysical Abstracts:

Sep 1, 1932

By Patrick D. McMaster

"INTRODUCTION According to the Roane Iron Co. of Rockwood, Tenn., the Chamberlain. Barnardville iron deposit produced approximately three million tons of iron ore previous to 1928. The deposit is divided into two synclinal bodies termed the north and south synclines. Production has come from the northern extremities of both bodies.The need for developing additional iron-ore reserves during the war prompted the Bureau of Mines to initiate an exploratory program on the Chamberlain-Barnardville deposit in February 1944, which continued until December 1944.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines 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 Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director."

Oct 1, 1946

By Ronald B. Stotelmeyer

This report summarizes studies of 28 National Forest roadless areas in Montana completed by the U.S. Bureau of Mines (USBM) in the period 1974-1993. It also briefly describes 20 areas for which field studies have not been conducted. All 48 of these roadless areas have been recommended for addition to the National Wilderness Preservation System or proposed as special management areas by the U.S. Forest Service (USFS) or the Montana congressional delegation. The Bureau studies indicate which parts of the roadless areas have a high likelihood for mineral-resource development. They also show where mineral production has occurred in the past and where abandoned mine workings (possible hazards) would be encountered. The number of mine and prospect workings found are a measure not only of surface disturbance, but of areas not wilderness in character. For the purposes of this report, mine refers to a property which produced (or is currently producing) a mineral commodity, a prospect is a property which has been explored but has no record of production.

Jan 1, 1994

By M. R. Geer

The Bureau of Mines surveyed the solid wastes that have accumulated from coal mining in Washington, Oregon, and Montana. Location, amount, character, and condition were determined, and both economic and environmental factors were considered. Areas covered by waste comprise 800 acres in Washington, 5 acres in Oregon, and 1,200 acres in Montana. In a few cases waste is being utilized, particularly cinder from burned refuse dumps, as fill in road construction and as a ceramic raw material. It is estimated that wastes deriving from coal mined for electric power generation by 1974 may amount to 3 million tons of washery refuse, 2.7 million tons of fly ash, and 1,000 acres of spoil banks.

Jan 1, 1969

By T. E. Gray

This report describes the preparation characteristics of the significant coalbeds in Harrison County, W. Va. It is one in a series of Federal Bureau of Mines reports planned to determine coals suitable for the production of metallurgical coke, either as mined or after beneficiation. Over 6.5 million tons of coal was produced in Harrison County, W. Va., in 1958, of which over 3.7 million tons was cleaned mechanically in seven preparation plants. All of the coal cleaned was from the Pittsburgh bed. It has been estimated that more than 1,816 million tons of coal remains in the county in beds 12 inches or more thick. The Pittsburgh and Redstone beds were selected by the Bureau for a study based on current production rates and estimated minable reserves. Sample locations were selected following a study of the literature, conferences with mining engineers and mining company officials in the field, and examination of the available sites. Six samples were collected from the Pittsburgh bed, and three samples came from the Redstone bed, Float-and-sink tests of the samples collected from the Pittsburgh and Redstone beds showed that neither coal could be upgraded to a metallurgical fuel under the standards set up for this study, even after intensive preparation. Finer crushing of the samples moderately increased the yields and slightly reduced both the ash and the sulfur contents in the 1.30-specific-gravity float fractions. Finer crushing slightly decreased the yields in the 1.58-specific-gravity float fractions, whereas it reduced the sulfur content 0.11 percent for the Redstone sample and 0.46 for the Pittsburgh sample.

Jan 1, 1961

By W. R. Hardwick

This paper describes mining methods and practices of the Chino Mines Division, Kennecott Copper Corp., Grant County, N. Mex. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. A similar program was conducted from 1928 to 1939, which helped to improve the efficiency of mining operations. The primary purpose of the program is to promote development and conservation of our mineral resources by disseminating technologic information on methods, practices, and related features in mining mineral deposits. It is expected that the program will: (1) Promote efficiency in operating mines; (2) assist operators and engineers in evaluating and developing new mineral deposits; (3) provide data for engineering curriculums in mining schools; and (4) furnish performance and cost data for revising engineering handbooks and for inclusion in engineering textbooks.

Jan 1, 1958

By J. F. McIlwain

As part of its goal to minimize the requirements for critical materials, the Federal Bureau of Mines has investigated the consolidation of an iron-base superalloy (20 pct Cr, 5 pct each Ni and Mn, 1 pct each C, W, Mo, and Cb, and the balance Fe) and its modifications by powder metallurgy (P/M) techniques. Vacuum-atomized, prealloyed powder was used. Consolidation was by sintering of cold-pressed alloy powder, or by forging plus rolling or extrusion of canned powder. Several commercial lubricants were evaluated in the pressing operation. At 50-tsi compacting pressure with up to 3 wt-pct lubricant, green strengths did not exceed 1,000 psi. Powder sintered just below the solidus temperature attained a tensile strength of 69,000 psi and 4 pct elongation. Liquid-phase sintering produced higher densities, lower tensile strengths, and nil ductility. Canned powder was forged and rolled at 1,200° C, yielding a 100-hr rup¬ture strength of 9,800 psi at 815° C and a room-temperature tensile strength of >130,000 psi at 6 pct elongation. Heat treatment of modified P/M iron-base alloy containing 0.63 pct C resulted in a 100-hr rupture strength of 17,000 psi. Oxidation resistance at 805° to 815° C of the forged and rolled P/M iron-base alloy was similar to that of the cast iron-base alloy and supe¬rior to conventional stainless steels.

Jan 1, 1981

By Paul M. Tyler

Graphite occurs in many places in the United States, but previous to 1914 the domestic production amounted to only 15 to 20 per cent of the natural graphite consumed in this country. Including artificial, graphite, the proportion was about 25 per cent. During the World War the production of both natural and artificial graphite increased until, in 1918 it, contributed more than one-half of the available supply, and since 1919 the proportion has not fallen below 40 per cent. Except during the war period, however, this apparently increasing independence has not been due to any large increase in production from domestic mines. It simply reflects a larger output of artificial graphite and reduced imports of Ceylon lung and chip, grades which have never been produced in substantial quantity in the United States. DOMESTIC DEPOSITS3 American graphite deposits, though numerous and often large, are characteristically low-grade. They constitute an abundant source of potential supply, but in normal times they have proved relatively costly to work, and even at the same price the various products have never been able wholly to displace certain imported qualities, notably crucible grades from Ceylon and pencil graphite from Mexico.

Jan 1, 1929

By D. R. Babich, E. R. Bauer

National Institute for Occupational Safety and Health (NIOSH) researchers are conducting a cross-sectional survey of equipment noise and worker noise exposures in the mining industry. Surface and underground limestone is one commodity recently surveyed. The sound levels of mining and processing equipment were recorded to identify noise sources. Full-shift worker noise exposures were completed to determine the exposure of various occupations. This paper presents the results of the noise research conducted in both underground and surface limestone mines, detailing the equipment likely to cause worker overexposures, and the occupations experiencing overexposures. Implications for worker noise exposure reduction are also reported.

By R. O. Kneisley

This U.S. Bureau of Mines report summarizes a study of large-scale strata response to longwall mining at a western U.S. coal mine. This study utilized surface and subsurface measurements, geologic mapping, in situ stress measurements, and pressure cell readings to characterize strata behavior. Preliminary analysis of surface subsidence and time-domain reflectometry (TDR) was used to determine a suggested main roof caving sequence. Coal ejected from the face apparently resulted from brittle failures that occurred because of lack of significant yield zone development. The combination of a strong coal with pronounced directional behavior, low overburden pressures, a good caving roof, and a high-production environment that minimized time-dependent loading apparently reduced yielding of the longwall face. The panel 1 headgate-entry design appears adequate; however, the abutment pillar and adjacent panel tailgate rib are highly stressed and may contribute to problems during second panel mining. The small chain pillar yielded after passage of the face, but the pillar width may be near maximum since evidence of a stressed core exists.

Jan 1, 2010

By P. D. Kovscek

The Bureau of Mines equipped a longwall shearer with a water-jet-assisted mechanical cutting system to determine the effect of the high-pressure sprays on machine performance, airborne dust levels generated, and size of particles formed. Testing was conducted on a simu-lated coal block (coalcrete) while cutting at a water pressure of 190 psi and at water-jet-assisted pressures ranging from 1,000 to 6,000 psi. The shearer motor energy used by the shearer while cutting coalcrete was determined for each cutting condition. Results indicate that the motor energy required by the shearer for each ton of material cut did not vary significantly as the water pressure was increased. Results of dust measurements recorded near the cutting drum indicate that at water pressures above 3,000 psi, dust reductions up to 85 pct were achieved com-pared with cutting with conventional sprays. Analysis of the particle size distribution during cutting showed that increasing the water pres-sure resulted in increased median particle size. In light of these results, various mechanisms for water-jet-assisted cutting are discussed.

Jan 1, 1986

By Audrey A. Soja

The Bureau of Mines investigated beryllium resources, production methods, and production costs to estimate the quantity of beryllium available for future use. Eight mining districts and 12 deposits are included in the study; lack of data precluded the evaluation of resources from 6 nonproducing and undeveloped deposits. The study revealed that demonstrated beryllium-bearing resources should be sufficient to meet domestic needs and those of other market economy countries (MEC's) well into the 21st century. Total demonstrated beryllium-bearing in situ resources from MEC's are estimated at 118 million metric tons (Mmt) of ore containing approximately 33,000 mt beryllium metal. Approximately 111 Mmt ore containing 29,000 mt beryllium was included in the cost analysis and availability sections of this study. Three Brazilian districts currently produce beryl ore, and one domestic company, Brush Wellman Inc., produces bertrandite ore. Brush Wellman Inc. owns and operates the only MEC facility in the Western Hemisphere for extracting beryllium values from beryl and bertrandite and is the beryllium industry's only fully integrated corporation.

Jan 1, 1986

By John M. Devine

Hydrogen sulphide associated with natural gas was noted as early as at Point Albino, Canada. The presence of this impurity was recognized also in other of the earlier oil and gas fields, although the occurrence was by no means common. However, in recent years, with the development of the producing zones of test Texas and the Texas Panhandle, the Production of "sour" crude has increased greatly and hydrogen sulphide has proved a generally troublesome factor--frequently a major problem--in the drilling and operation of many wells in those areas. The problems arising from the drilling and producing of oil or gas wells in hydrogen-sulphide areas, fall under two general divisions: safety problems and corrosion problems. Mention is made of a third division which is closely related to the other two, that of treating--or the development of processes for the removal of hydrogen iron the standpoint of safety and health hazards, hydrogen sulphide in the petroleum industry has been discussed in a number of publications. Likewise, the problem of hydrogen-sulphide corrosion of production equipment has been given considerable attention in the literature.

Jan 1, 1931