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By John J. McClelland

The Bureau of Mines conducted a study of longwall plow operations to identify dust sources and existing control technology. Three longwalls employing either the high-speed overtaking or conventional method of mining were surveyed. Principal operating parameters and on-site dust control technology at the time of each survey are described. Short-term gravimetric and instantaneous sampling results are discussed in detail. The relationship between longwall dust levels and dust control technology was examined.

Jan 1, 1988

By M. D. Schlesinger

Mercury exists in coal in minute quantities, but the large tonnages of coal consumed could represent relatively large amounts of mercury entering the environment. Limits have now been placed on the emission of mercury, and it is important that reliable analytical methods be available to the chemist. The Bureau of Mines has evaluated analytical techniques used by a number of laboratories; most used vapor phase atomic absorption as the final detection method. Neutron activation was used by some of the laboratories. All of the methods described could be applied, but they require careful manipulation to prevent loss or mercury contamination. In the samples analyzed the mercury content ranged between 0.05±0.01 and 0.4l±0.06 part per million.

Jan 1, 1972

By Charles Vaught

This paper discusses the fact that US coal mining organisations are losing the knowledge they need in order to be able to respond to emergencies. The authors note that knowledge management provides a useful perspective from which to view the problem, but that the debate about what constitutes knowledge should be broadened to include a debate about what constitutes management. It is argued here that knowledge is actually shared knowing distributed across group members; that such knowledge can be managed by cultivating it; and that narrative is the medium through which this may be done. The paper then examines NIOSH research that has attempted to use such an alternative knowledge management approach to help potential mine emergency responders better deal with the predicaments they are likely to encounter on-site.

Jan 1, 2006

By H. Kim, R. W. Plummer, T. J. Stobbe

"The probability of developing coal workers' pneumoconiosis (CWP) varies among miners in different geographic areas, coal seams, and jobs. Many studies have revealed the correlation between mineral content and the frequency and severity of CWP development still remains controversial. Furthermore, the mineral content and its variability in different areas is unknown.Since mineral content is expected to vary from location to location within a mine, between mines, between coal seams, and over time, this information will be valuable in understanding the variations in CWP incidence, as well as in establishing the appropriate kinds of dust to use in toxicological research programs studying CWP.Size-selective airborne dust samples were collected using 4-stage cassette impactors at 9 different locations in each of five coal seams. These coal seams were the Upper Freeport, Pittsburgh, Kittaning, Coal Burg, and Pocahontas. Mineralogical analyses were done by a x-ray powder diffraction photographic technique.Common minerals found in coal mine dust were illite, calcite, kaolinite, quartz, siderite, dolomite, gypsum, anhydrite, and pyrite. The distribution of minerals in interand intra location samples will be reported. Early results on the mineral content show wide variations between locations.in a mine and between coal seams, and small, but significant, variations between particle sizes.INTRODUCTIONIn spite of its long history of incidence, and the large amount of research conducted on it, coal workers' pneumoconiosis (CWP) is still prevalent among coal miners and needs further research to develop effective preventive and remedial measures. Although the dose-response relationship between simple CWP and coal mine dust has been established (1), the causal agent(s) and the mechanism(s) involved in the progression of simple to complicated CWP are not yet defined. Many plausible hypotheses have been made to explain the mechanisms involved in the disease progression however none of them is satisfactory. In addition, the source of variation in occurrence of CWP among miners in different geographic areas (2), rank of coal seam (3,4), and job (5) remain unsolved."

Jan 1, 1988

By Richard J. Mainiero, Marcia L. Harris

The New York State Department of Transportation recently commenced highway widening and drainage improvement projects in Clarence and Amherst, NY. Drainage improvements including the installation of storm sewer lines required excavation to a depth of 2.5 m (8.2 ft). In September 2002, NYSDOT stopped further blasting when 800 ppm CO was detected in the basement of a house near the blasting site. At the insistence of NYSDOT, the general contractor developed a new blast plan with the assistance of an environmental consultant. The plan provided for the installation of multi-gas monitors in buildings of special concern and/or with basements and residential type CO monitors in all other buildings within 100m (330 ft) of the blast. The multi-gas monitors would be remotely monitored. The plan provided action levels which would ensure public safety. The blast design was also modified to allow for better venting of CO. Blasts were limited to 20 ft lengths. The overburden was to be removed from the rock and blasting mats put in place to prevent flyrock. Approximately twenty feet of trench adjacent to the blast was left open to allow ground movement and gas release. The use of CO monitors was effective to alert occupants of a building to the presence of CO. The most effective appeared to be the residential type CO alarms with digital readouts. They were simple and easy to use and allowed the public to participate in the process. False alarms were repeatedly received with the more sophisticated instrumentation. Residential type CO monitors are preferable to warn people near blast sites. More sophisticated instrumentation should be avoided unless personnel are experienced in its use. A general overview of the blasting and monitoring is presented and discussed. The use and effectiveness of residential type CO monitors and multi-gas monitors are discussed.

By Joan T. May

Anhydrous methods were tested for the extraction of beryllium from low-grade source materials. The purpose of the investigations was to find new extraction processes that are applicable to domestic ores. Beryl, helvite, and phenacite materials containing from 0.1 to 2.8 percent BeO were used as starting materials for direct halogenation tests and pretreatment followed by halogenation. The results of the investigations showed that direct fluorination and carbide-chlorination are two practicable methods that can be applied to low-grade concentrates. Treatment of concentrate-carbon mixtures with anhydrous hydrogen fluoride extracted 99 percent of the beryllium in the concentrate; the soluble fluoride product, converted to an oxide, contained 70 percent BeO. Chlorination of beryllium-silicon carbide, prepared from low-grade concentrates, extracted beryllium into the volatile chloride product.

Jan 1, 1962

Provide the U.S. mining industry with a user friendly computer program to calculate stresses in underground coal mines in order to improve safety conditions for mine workers. Capabilities of MULSIM/NL MULSIM/NL (multiple seams, nonlinear) is a three-dimensional boundary-element method (BEM) program developed at the U.S. Bureau of Mines for stress and displacement analysis of coal mines. It can analyze one or two parallel seams that can have any orientation with respect to the Earth's surface. Three main new features distinguish MULSIM/NL from its predecessors: (1) non¬linear material models, (2) multiple mining steps, and (3) energy release and strain energy computations. MULSIM/NL has six material models for the in-seam material: (1) linear elastic for coal, (2) strain softening, (3) elastic plastic, (4) bilinear hardening, (5) strain hardening, and (6) linear elastic for gob. The multiple mining step capability enables the user to efficiently simulate a changing mine geometry. Finally, MULSIM/ NL computes energy release rate due to mining using the most recent concepts advanced by Salamon.

Jan 1, 1993

By W. K. Sawyer

In this Bureau of Mines investigation, one-and two-dimensional gas reservoir simulators were combined in such a manner that pressure distributions both in an induced vertical fracture and in the surrounding formation, could be determined as a function of time for any specified well production rate. The technique used consisted basically of the alternate ust of one-and two-dimensional algorithms for obtaining new pressure distributions in the fracture and in the reservoir, respectively. The pressures at adjacent reservoir and fracture nodes were used to calculate flow rates from the formation into the fracture, which provided source terms for both algorithms. The combination model developed provides the only known means of simultaneously simulating transient gas flow in a vertical fracture and the surrounding formation. Thus, the technique developed would be useful in locating wells in a gas storage field in that the effects of both fracture length and conductivity could be considered prior to drilling and fracturing operations. In addition, it will be helpful in analyzing pressure drawdown tests in a vertically fractured gas well since the entire test can be readily simulated for a wide range of reservoir and fracture properties.

Jan 1, 1974

By Allen D. Look, J. Howard Bird

"INTRODUCTION The Phelps-Dodge Corp. New Cornelia Branch open-pit copper mine operated without a fatality in the drilling and blasting department from December 13, 1937, to April 1, 1947, and continuing.Between the dates named the explosives crews had a total of 746,520 man-hours of exposure and handled 12,000 tons of explosives, over 770,000 detonators, 2,300,000 feet of fuse, and 7,700,000 feet of Primacord in loading holes to break 116,780,000 tons of material.It is the purpose of this paper to record the procautions taken to insure safe handling of explosives at this operation where safety is definitely a matter of forethought rather than chance.GENERAL INFORMATIONThe New Cornelia Branch open-pit mine operates on a large, low-grade, disseminated-copper deposit about one-half mile south of Ajo, Ariz. The pit is approximately oval; the ore body being some 4,800 feet long and 2,750 feet wide. Ore is mined with electric shovels loading into railroad cars. All benches in- the pit are 40 feet in height except two, which are 60 feet high.The New Cornelia ore body differs from most porphyry-copper deposits in being hard and siliceous. In common with the other low-grade porphyry-copper deposits, continued operation is possible only with economical handling of large tonnages. This has necessitated a great deal of study in the evolution of a safe and efficient method of handling the large quantities of explosives needed in breaking this hard-rock material."

Feb 1, 1948

1. Mining to prevent and control underground acid formation should begin with education imparted through: (A) Course work at mining schools to teach prospective engineers. (B) Training of engineers presently employed in the mining industry through appropriate mining extension courses. 2. Considerable need exists to devote more attention to: (A) Hydrogeologic studies of mining areas to enhance the planning of new mines and the abatement program of existing mines. (B) Additional research to explore methods of dewatering the strata associated with mining areas. (C) Further effort to develop sealants for preventing contact between water or oxygen and the acid producing material associated with the coal seam.

Jan 1, 1970

By Edward A. Barrett, Lynn L. Rethi

Recent studies have shown that miners performing construction, maintenance, and repair (CMR) work activities in the conduct of their jobs incur from 39 to 65 percent of all reported injuries in the mining industry, The number is particularly high at surface aggregate operations; however, the problem exists at all mining locations and commodities. To address this issue, an interactive, (3-D) slides training exercise, Hazard Recognition Training Program for Construction. Maintenance and Repair Activities, was developed. The purpose of the exercise is to teach work& to recognize CMR hazards in the workplace and to deal with them using accepted safe work procedures. It was field tested using a total of 340 persons from surface mining operations in six states. The subjects were tested before and after the training intervention to determine if objectives of the instruction were achieved. Results indicated that 7 1 percent of the participants showed improvement in ink test scores. Following the posttest, subjects responded to a seven question Likert scale. These questions related to the validity of the exercise and the utility of the training program. More than 93 percent of the miners reported that they "learned something new from the training" and over 94% said they "would use these practices to work more safely".

By Todd M. Ruff

A training software package for new mine employees, called Miner Training Simulator (MTS), has been developed by researchers at the National Institute for Occupational Safety and Health. MTS is a computer-based tool that allows a trainee to enter a simulated mine and interact with his/her surroundings in order to learn basic mining concepts, safety procedures, mine layouts, and escape routes. The training simulator software and instructions for its use are described in this report. Also, each mine using the software will have different requirements with regard to safety training. To customize the simulator for these differences, an interpreted scripting language is used to define interactions between the trainee and the virtual mine and objects in it. The scripting language, called Tool Command Language, uses simple commands to control various actions in the simulation, such as sounds, safety messages, hazards, and movement of objects. The basics of the scripting language are described here, along with many examples and instructions for building a script for MTS.

Jan 6, 2001

By Raja V. Rarnani, Robert L. Frantz

"Co-Directors, Generic Mineral Technology Center for Respirable DustEarly in the 1980s, the U.S. Bureau of Mines initiated the concept of the Generic Center, incorporating it into its mining research program, and in 1983, the Generic Mineral Technology Center for Respirable Dust was established. The Generic Center concept was first envisioned by the U.S. Bureau of Mines as a way to bring together the various different scientific, engineering and medical research interests in the respirable dust area to effect a coordinated and efficient organization for advancing knowledge in that field. The result was a combination of the collective talents and skills of more than 100 scientists, engineers, medical personnel and graduate students, through the formation of a consortium of five major research universities, including medical facilities, to perform respirable dust research. The Generic Mineral Technology Center for Respirable Dust consortium comprises The Pennsylvania State University (with its Hershey Medical Center) and West Virginia University (with its Medical Center) as the lead universities and the University of Minnesota, Massachusetts Institute of Technology and Michigan Technological University as affiliates.Although respirable dust-related disease remains the nation's worst industrial hazard, the fundamental understanding of all aspects of respirable dust associated with the mining and milling industries, including the interaction of dust and lungs, has grown significantly over the past near-decade toward the larger effort to reduce the incidence and severity of disease caused by respirable dust. Continued progress toward making the mine work environment cleaner and healthier remains the immediate objective of the Respirable Dust Center.The Respirable Dust Center's research program and technology transfer activities, described in this paper, exemplify the Generic Center concept first envisioned by the U.S. Bureau of Mines. Interdisciplinary and interactive studies continue to result in significant progress toward making mine atmospheres cleaner and healthier."

Jan 1, 1995

By Joseph Grumer

In addition to nine powder and gaseous extinguishants of propagating Pittsburgh seam coal dust-air explosions earlier evaluated,6 10 other powders have similarly been evaluated under like conditions such that wall quenching of the coal dust-air flames was virtually absent and the dust concentration was temporally and spatially uniform to within about ±5 percent. None of the newly examined extinguishants was better than Purple-K (potassium bicarbonate); the 10 of this report are anhydrite (calcium sulfate), monobasic (4 types) and dibasic ammonium phosphate, natural and synthetic cryolite (sodium fluoalumi-nate), sodium sulfate, and tricalcium phosphate. Except for anhydrite, sodium sulfate, tricalcium phosphate, and the cryolites, these materials were about equally effective, when present in relatively low concentrations (weight-percent of the coal dust-extinguishant mixture). The maximum oxygen concentration for the extinguishment of otherwise uninhibited coal dust explosions and the influence of coal dust particle size and the volatile content of the coal were also explored. For the present, the choice of the inhibitor among the good ones evaluated is not as critical as the system to be used to deploy the extinguishant against a coal dust explosion.

Jan 1, 1973

By G. M. Martinez

A cell concept adaptable to large-scale electrowinning of zirconium metal from zirconium tetrachloride was investigated by the Federal Bureau of Mines. Tests were made in twin cells, each 12 inches in diameter by 33 inches long. Electrowinning was performed in one chamber from which the electrolyte was transferred after electrolysis to the other chamber where it was renewed by the introduction of ZrC14 by direct sublimation. The formation of a salt plug in the connecting pipe provided a seal between the chambers. Optimum electrolyte composition, with respect to quality of the metal product (91 pct meeting ASTM standards except for the oxygen content) and current-carrying capability (about 350 amp) was determined to be 16.7 wt-pct NaF-83.3 wt-pct NaCl mixture plus ZrC14 equal to about 3 wt-pct zirconium. A twin-cell design incorporating the unit operations covered by this investigation is proposed.

Jan 1, 1976

By E. J. Kloos

The Bureau of Mines developed a test for evaluating gas masks designed to protect against phosphine gas; phosphonium iodide is used as a source of phosphine. Gas masks approved by the Bureau for respiratory protection against phosphine include the GMC-SS-1, Mine Safety Appliances Co.; the LG-10 and LG-10G, Willson Products Division, The Electric Storage Battery Co.; and the 084-PHOV-R, Acme Protection Equipment Co.

Jan 1, 1966

By John Fitzpatrick

In this Bureau of Mines investigation a device was developed that permits the determination of the modulus of elasticity of the stress-relief cores obtained in the process of making in situ stress measurements. This determination is made by hydraulically loading the external surface of the stress-relief cores and by measuring the corresponding borehole deformation. The theoretical relationship between the borehole deformation, the applied pressure, and the modulus of elasticity is presented. Also, experimental results obtained from measurements on a simulated stress-relief core made of aluminum and on a limestone stress-relief core are given. Because of the symmetrical loading obtained with this device, the isotropy of the core material can be evaluated. With this device it is also possible to study the effect of eccentricity, that is, the effect within cores in which the inner hole is not coincident with the long axis of the specimen.

Jan 1, 1962

By W. Dan Walker

In an effort to keep mine hoist accidents to a minimum and to impart to managers and workers the essential elements that enter into safe installation and maintenance of hoisting equipment, the Bureau of Mines presents this Information Circular as a guide. Hoisting of men and materials is an essential operation in many mines and has become so commonplace that some persons are likely to ignore day-to-day inspections or become lax in the operating phases. With proper maintenance and operation, hoists can be exceptionally safe. However, lack of strict attention can invite tragedy or costly shutdowns.

Jan 1, 1961

By A. B. Hooker

Investigations at the Pittsburgh Experiment Station of the Bureau of Mines have shown that satisfactory operation of a flame safety lamp depends not only upon proper design and assembly of the lamp but also upon the kind

Jan 1, 1945

By David W. Wisecarver

This report describes a tool to engage and/or place a Bureau of Mines type gage to measure borehole deformation in a horizontal , 1½ - inch - diameter , stress relief borehole . The tool was successfully used at a borehole depth of 105 feet . Practical usage up to borehole depths of 200 feet might be realized . The tool was designed to work inside EX- size ( 1½ - inch ID ) diamond - drill drive casing used as drill rod and through which the deformation gage is guided into an EX- size stress relief borehole . Through laboratory experiments it was found that by exercising a reasonable amount of care the deformation gage could be placed at a point within a ± .01 foot distance of a predetermined depth in a horizontal EX- size hole and that the deformation measuring piston or plunger of the gage could be oriented in the borehole within 0.5 ° of a preselected angle of orientation in a vertical plane .

Jan 1, 1964