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To provide operators of large-opening mines with a ventilation planning tool that will help them develop a healthier, safer, and more efficient ventilation system in the underground workplace.

Jan 3, 2006

By Sean Gallagher, John R. Bartels, Dean H. Ambrose

Remote operation of continuous miners has enhanced the health and safety of underground miners in many respects; however, numerous fatal and non-fatal continuous miner struck-by accidents have occurred when using remote controls. In an effort to prevent these injuries, NIOSH researchers at Pittsburgh Research Laboratory examined the workplace relationships between continuous miner operators and various tramming modes of the equipment using motion captured data, predicted operator response times, and field- of- view data to determine causes of operator-machine struck-by events in a virtual mine environment. Factors studied included machine speed, direction of escape, operator facing orientation relative to the machine, work posture, distance from machine, and operator anthropometry. Close proximity to the machine, high machine tramming speeds, a right-facing orientation and operator positioning near the tail all resulted in high risk of being struck. It is hoped that this data will provide an improved rationale for operator positioning for remotely operated continuous miners.

By W. M. Dressel

This Bureau of Mines report describes a shaft closure demonstration project in which 11 inverted pyramid-shaped plugs were used to plug abandoned open mine shafts in Galena, KS, The inverted pyramid-shaped forms, fabricated from steelplate, were designed so that the inverted base would be larger, by 4 ft on a side, than the approximate size of the shaft opening at the surface residuum-solid rock interface. After the surface openings of the shafts were trimmed with a backhoe, the steel forms, complete with reinforcing, were lowered into the openings and filled with concrete; the remaining portions of the openings above the plugs were backfilled to slightly above the surrounding surface level with waste rock and soil. Location and elevation monuments were installed for long-tern evaluation of the success of the project.

Jan 1, 1985

By Kathleen M. Kowalski-Trako?er

National Institute for Occupational Safety and Health re­searchers conducted a study to investigate the human response issues related to wearing a self-contained self-rescuer (SCSR). The goal was to develop training to educate miners on what they could expect from their units during an escape. Subjects included miners who had experience wearing SCSRs, manu­facturers, and researchers. Results identified nine key areas of concern: (1) starting the unit, (2) unit heat, (3) induction of coughing, (4) unit taste, (5) difficulty in breathing while wearing the unit, (6) quality of the air supplied, (7) nose clips, (8) goggles, and (9) the behavior of the breathing bag. In addition, researchers reviewed the literature on human response under duress. This article describes the expectations training program, which comprises the findings of the SCSR study and what is known about the normal human response in an emergency. The authors present background on SCSRs and the SCSR switchover procedure mandated in the recent federal Mine Improvement and New Emergency Response Act of 2006, which provided the impetus for the expectations training. Keywords disaster, escape, mining, self-contained self-rescuer, training

Jan 1, 2008

By Kenneth B. Higbie

METALLURGICAL ACTIVITY in 1963 was again dominated by the insatiate demands of research and development conducted in conjunction with the nation's defense and aerospace programs. An increasing effort was noticeable throughout the year, however, to apply to the commercial field many of the processes and techniques that have been developed by government-sponsored research. Particularly effective has been the Industrial Applications Program of the National Aeronautic and Space Agency through which many of the technological advancements made during the course of NASA research and development have been published and released to the public. POWDER TECHNOLOGY Powder metallurgy techniques for fabricating metals, not long ago declared outmoded because of improved casting and shaping methods, have since made an astonishing comeback. Traditionally mechanical pressing of powder shapes has been employed when melting and casting was difficult or impossible, when phase relationships needed to be sidestepped, or when machining costs could be avoided. Hence, it has long been used for producing relatively small special shapes of high-melting metals and alloys. Small iron parts produced with a punch and die have been common for many years, but powder metallurgy techniques are now applicable to a wide range of materials and items. Hard-to-handle materials including refractory metals and their alloys are now rolled, forged, or extruded from billets made by sintering isostatically compacted powders. The major element of the powder metallurgy industry still comprises iron shapes, however, and two-thirds of the annual 100,000 tons of powder metallurgy products are made of iron. The largest single user of powder-forming techniques is the automobile industry which currently consumes 14,000 to 16,000 tons of iron powder per year. A typical 1963 model auto contained more than 100 pressed powder parts (e.g., transmission gears, timing gears, sprockets, ball joint suspensions) totaling 5 to 7 pounds per car. Some of these powders are used in self-lubricating parts of porous copper and copper alloys containing as much as 20 volume-percent lubricating oil. The expanded use of powder techniques, coupled with

Jan 1, 1964

By Leonard J. Prosser, Dennis R. Dolinar, John L. Ellenberger, Gabriel S. Esterhuizen, Anthony T. Iannacchione

The room-and-pillar mining method is used extensively in underground limestone mines in the Eastern and Midwestern U.S. The rock mass is typically a near-horizontal, bedded deposit at relatively shallow depth. A survey of 34 mines was conducted in which data on roof spans, rock mass properties and support practices were collected as part of a National Institute for Occupational Safety and Health research project into ground control in limestone mines. The average room width is 13.5 m (44 ft), accommodating large mechanized equipment. The results show that the immediate roof beam can consist of many individual layers and can contain several near-vertical joints. In spite of the room widths, the roof is naturally stable in many mines. Observed roof instabilities can generally be related to excessive horizontal stresses or unfavorable geological structures that cause block fallout or beam failure of the bedded roof rocks. The survey showed that the rock mass quality of the limestone does not vary significantly throughout the Eastern and Midwestern U.S. Roof conditions and the need for support were found to be closely related to the thickness and competence of the first layer of limestone in the roof. The findings highlight the need to identify local geological structures and the roof beam characteristics so that support alternatives can be evaluated. Monitoring and observational technologies that are available for identifying potentially unstable roof are presented, which include: roof characterization using the Rock Fall Risk Index, automated logging of roofbolt hole drilling, microseismic monitoring and displacement monitoring.

By R. K. Linn

The New Idria Mining and Chemical Co. owns and operates the New Idria mine in southern San Benito County, Calif. During 1957-59, the New Idria mine was the largest producer of mercury in the United States and its alltime production of over a half-million flasks was exceeded only by one mine. It is one of the oldest and most consistent producers in California. With the exception of 1921-22, the mine has an annual production of mercury dating back to 1854. This paper by the Federal Bureau of Mines describes the exploration, development, mining, and furnacing of mercury ore at the New Idria mine. Figure 1 is a view of the furnace plant of the New Idria mine. The purpose of this report is to promote the development and conservation of our mineral resources by dissemination of technological information on mining and processing procedures, and related practices at operating mines.

Jan 1, 1961

By J. B. Zadra

Much has been published by various investigators on the use of activated carbon for adsorbing precious metals from cyanide solution and pulp. For the benefit of the reader, a list of these earlier publications appears at the end of this report. The present paper deals only with a process for extracting gold from gold-laden carbon and re-use of the de-adsorbed carbon. At the Getchell mine, Redhouse, Nev., experiments have been in progress for several years concerning the use of activated carbon to adsorb gold from their slime circuit pulp. The experimental work has been successful. Their practice has been to ship the gold-laden carbon to a smelter for treatment, which meant the total loss of the carbon in addition to smelter and freight, charges, all of which proved costly and wasteful.

Jan 1, 1950

By J. J. Wallace

This report describes the initial phase of Bureau of Mines research in the hydraulic mining of bituminous coal. The mining site and equipment are described, and the test procedures and results obtained with a bar-mounted monitor are given. Tests showed that hard Pittsburgh-bed coal can be mined hydraulically from a solid face at water pressures of 4,000 pounds per square inch.4 Coal was penetrated to a depth of 4 feet in 20 seconds with 225 gallons of water per minute coming from a 3/8-inch nozzle at 4,000 pounds per square inch pressure. Some difficulty was encountered in cutting the binders occurring in the coal; it was not possible Lu penetrate directly the overlying draw slate.

Jan 1, 1961

By H. R. Beard

The Federal Bureau of Mines investigated the absorption of radium and thorium from waste uranium leach liquor by clays and other materials. This work was conducted in support of the Bureau's goal of minimizing the environ¬mental conflicts, impacts, and occupational hazards Associated with mining and mineral processing operations. Tailings and soil samples from Wyoming and Utah were contacted with tailings liquors to determine the degree of absorp¬tion. Absorption ranged from 0 to 99 percent for radium and from 0 to 31 per¬cent for thorium. Some samples, which readily absorbed radium, were contacted with various salt solutions that could be present in tailings solutions to determine their effectiveness as desorbents. The desorption of radium ranged from 0.06 to 100 percent. An alpha-spectrometric method was used to determine the radium and thorium, concentrations in the solutions and the solids.

Jan 1, 1979

By F. Fraas, J. E. Conley

"The problem of recovering potash from the mineral polyhalite (K2SO4.MgSO4.2CaSO4.2H2O), occurring in large quantities in the salt beds of Texas and New Mexico, has been under investigation at the Nonmetallic Minerals Experiment Station of the U. S. Bureau of Mines continuously since 1928. Most of the results previously obtained have been published in technical journals and in a series of Bureau of Mines Reports of Investigations.The experiments described in the present report were performed to ascertain whether a continuous countercurrent extraction of calcined polyhalite by hot water would yield satisfactory recoveries and concentrations of sium sulphate in the top liquor. Previous investigation by Storch 4 had shown that the rate of solution of uncalcined polyhalite was too slow to be of value in an industrial process, and Storch and Clarke 5 had demonstrated that calcination of the polyhalite greatly, accelerated the rate of solution in hot water, allowing most of the potassium sulphate to be readily extracted."

Sep 1, 1933

By Lloyd H. Banning

Crucible-smelting tests at the Northwest. Electrodevelopment Laboratory and a pilot-plant test on electric smelting of western phosphate rock for the Westvaco Chlorine Products by the Tennessee Valley Authority indicated that the small vanadium content of the rock is concentrated in the ferrophosphorus by-product of Phosphorus smelting. This research is concerned' mainly with recovering vanadium and phosphorus froth the ferrophosphorus produced from western phosphate rock. Exploratory tests were made of several methods of treating vanadiferous ferrophosphorus. Attempts to separate vanadium as a carbide dross by saturating molten ferrophosphorus with carbon were unsuccessful. Volatilization of phosphorus from ferrophosphorus was accomplished to some extent, both with and without addition of sulfur in several forms, but elimination of phosphorus was not complete. Brief testing in a small experimental converter on oxidation of vanadium and phosphorus; into a slag by blowing with air showed promise. A method that comprised fusing vanadiferous ferrophosphorus mixed with soda ash under oxidizing conditions gave encouraging results and was tested beyond the preliminary stage. A slag product of the fusion contained most of the phosphorus and vanadium as water-soluble sodium phosphate and. virtually water-insoluble sodium vanadate. After leaching the sodium phosphate froth the slag, the leach residue was reroasted with soda ash and salt. This roasted product was leached again with water to extract the vanadium.

Jan 1, 1951

By Noel N. Moebs

Bureau of Mines studies of mine roof fall problem in the Pocahontas No. 3 Coalbed of southern West Virgania and southwestern Virginia have established that type and sequence of rock are significant factors in roof competence. The poorest conditions occur where the immediate roof consists of slump structures and slickensided rock. The best conditions occur where the roof consists of a sequence that coarsens upward from shale to massive sandy shale. A small manual of color photographs of rock types was devised to aid in identifying drill cores. Proper identifications should enhance the prediction of areas of potential roof problems in advance of mining.

Jan 1, 1981

By K. P. V. Lei

The Bureau of Mines investigated molten-salt electrorefining as a practical method for reclaiming vanadium from vanadium scrap. An electrolytic process utilizing a KC1-LiC1-VC12 electrolyte at 615° C was developed for producing ductile vanadium with a purity over 99.9 percent. The recovery of the vanadium in the cell feed ranged from 88 to 93 percent with a current efficiency from 83 to 95 percent.

Jan 1, 1967

The safety analysis of shaft-sinking operations included a review of accident reports from coal and metal-nonmetallic mine shaft-sinking projects in the United States, a review of foreign and domestic shaft laws, and discussions with shaft contractors and Federal mine inspectors. Accident data were studied to identify the most common and the most severe types of shaft accidents and to determine their immediate and contributing causes. Additional factors such as worker training and experience, equipment and sinking procedures, regulations and enforcement practices were also investigated to determine their impact on shaft safety. The results of the study are summarized in recommendations for improved training of shaft miners and clarification of Federal shaft-sinking regulations. A guide to assist mine inspectors in examining shaft-sinking projects is also included.

Jan 1, 1977

By Slavoljub Makslmovic

One important element of the U.S. Bureau of Mines computer-assisted mining research program is the development of a reliable coal interface detection (CID) system. Several candidate CID concepts currently being investigated by the Bureau include use of natural gamma radiation (NGR), vibration, passive infrared, video, and radar. To help establish which CID sensor technologies need to be developed for a given seam, the Bureau has collected geological and mining practices data from over 460 underground and surface mines in the United States. Also, over 500 coal and rock samples have been obtained for laboratory analyses of ash content, sulfur content, heating value, and NGR. The Bureau's findings indicate that the immediate roof strata in 81% of the underground mines and 93% of the surface mines are made up of shale, draw slate, or claystone. The immediate floor strata in 88% of both the underground and surface mines consist of fireclay, shale, draw slate, or claystone. The results of the NGR testing indicate that the NGR method appears to be a potentially useful CID tool, provided that the immediate roof and floor are both composed of a high percentage of shale-type material.

Jan 1, 1993

By A. C. Fieldner

The past full year of war has increased greatly the demand for virtually all kinds of fuel, and the Bureau of Mines research and service facilities have been extended to meet these unprecedented requirements. Liquid fuels, such as aviation and motor gasolines, are fundamental to modern warfare. Bituminous coal and anthracite are needed, not only to servo the expanded industrial program for which coal normally is used but also to replace natural gas, wherever possible, and fuel oil in the Eastern States, New England, and the Pacific Northwest. Railroad transportation with energy derived from coal is replacing much of the motor-vehicle transportation that has been stopped or curtailed to conserve rubber. Pulverized coal hoe been sound to be a satisfactory and cheaper substitute for fuel oil in metallurgical heating furnaces. Celloidal fuel - a mixture of coal dust and oil - may offer a partial substitution for curtain coal-burning equipment. Several industrial experiments have been made with this type of fuel. The expansion of the steel industry in connection with the war program has required a corresponding increase in the production of metallurgical coke and its associated byproducts - light oil, tar, ammonium sulfate, and surplus gas. If the war is of long duration and new reserves of petroleum are not discovered, wartime trends from fuel oil to coal probably will not be reversed.

Jan 1, 1945

These proceedings consist of papers presented at two Bureau of Mines Technology Transfer Seminars for the purpose of disseminating recent advances in mining technology related to coal mine fire and explosion prevention. Primary, although not exclusive, emphasis is placed on underground coal mining. The papers address research accomplishments ranging from methods for detecting mine fires to remote sealing systems for extinguishing coal mine fires. Each paper represents the current state-of-the-art in the respective research categories. Presentations include research occurring from both Bureau in-house and contract efforts.

Jan 1, 1978

By Nick Barton

When the Q-system was launched in 1974, the name referred to rock mass classification, with focus on tunnel and cavern support selection. Besides empirical design of support, the Q-value, or its normalized value Qc, has been found to correlate with seismic P-wave velocity, with deformation modulus, and with deformation. The Q-system provides temporary or permanent support for road, rail, and mine roadway tunnels and for caverns for various uses. It also gives relative cost and time for tunnel construction for a complete range of rock qualities. There are also indications that Q has captured important elements of the cohesive and frictional strength of rock masses, with Qc resembling the product of rock mass cohesion and rock mass friction coefficient.

Jan 5, 2007

By Thomas W. Camm

This study was done to evaluate the costs of various dumping operations at waste and spoil piles. It has been theorized that accidents associated with dumping operations might be reduced by short-dumping rather than edge-dumping, but many operators have been reluctant to use short-dumping because they believe it is not as cost effective as edge-dumping. To evaluate this perception, researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health reviewed the costs of various dumping methods at waste and spoil piles. The study found that overall cost differences between the two methods were not significant in most cases. However, while overall cost differences between the two methods appear small, capital costs could be more significant when short-dumping if numerous dump sites are used concurrently. The choice of which method to use should be based on considerations of the safety of dozer and truck operators.

Jan 1, 2000