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By Richard Mainiero, Donald A. Hurd, James H. Rowland

In previous conferences the authors have reported on toxic fumes generated by the detonation of ANFO. The research reported here extends the earlier work to include an emulsion blasting agent and ANFO/emulsion blends. Explosive mixtures were shot in 4-inch Schedule 80 steel pipe in a chamber in the experimental mine at the Pittsburgh Research Laboratory (PRL). Following each shot, the fumes in the chamber were analyzed using on-line instrumentation. A major goal of the research was to gain a better understanding of the factors that lead to the generation of toxic fumes in blasting operations. Earlier studies have suggested that the high nitrogen dioxide and nitric oxide concentrations in product clouds might be the result of the poor confinement provided by relatively weak ground strata or the exposure of the explosive to ground water prior to shooting the shot. Various mixtures of ANFO and emulsion were detonated in schedule 80 steel pipe and galvanized sheet metal pipe to evaluate the effect of confinement. Explosive mixtures were also allowed to soak in water for less than one day, one week, one month, and two months to determine which explosive mixtures would be degraded and observe what effect this degradation had on fume production. Results indicated that the production of nitrogen dioxide increased with low confinement of the detonating explosive and with exposure of the explosive to water.

By K. K. Kelley

"INTRODUCTION The Bureau of Mines nitrogen peroxide process (2) 3/ for extracting manganese from low-grade ores is essentially a two-stage process involving the reversible reactionMnO2 + 2NO2 + 6H2O = Mn (NO3)2 . 6H2O (1).At lower temperatures this reaction proceeds to the rigth and affords a means of dissolving manganece and separating it from unreacted ore. At higher temperatures the reaction proceeds to the left and manganese dioxide is recovered and nitrogen peroxide regenerated for recycling. Evidently, therefore, the energy required for decomposition of manganous nitrate is a matter of practical importance. Similar information for certain other nitrates also is desirable beceuse the nitration step of the process produces appreciable amounts of nitrates of other metals, such as iron, aluminum, magnesium, calcium, and barium, some of which are not broken down in the evaporation and decomposition steps. Thus, a portion of the nitrogen peroxide is not directly available for recycling. Whether or not it is feasible to recover nitrogen peroxide locked in the more-stable nitrates depends partly on the energy required and the conditions necessary for their decomposition.To supply information bearing directly on these subjects, several researches were undertaken at the Pacific Experiment Station: (a) Heats of formation (24, 25, 26) of nitrates of manganese, magnesium, calcium, barium, and aluminum were measured at 298.2° K:; (b) low-temperature specific heats (23), in the range 51° to 298.2° K,, and entropies of nitrates of magnesium, calcium, barium, and aluminumm were determined; and (c) heat contents (21) above 298.2° K. of the nitrates of manganese, magnesium, calcium., and barium were measured. The results of these studies, when correlated by thermodymamic methods, permit evaluation, at any temperature of interest, of the energies required to decomposethe nitrates and furnish information concerning the equilibrium pressure temperature relationships."

Sep 1, 1944

By Paul C. McWilliams

The U.S. Bureau of Mines has, primarily through its contract program, used large-scale centrifuges to determine design criteria for tailing embankments. The centrifuge runs were made at two installations, the University of Cambridge, Cambridge, England and Sandia National Laboratories, Albuquerque, NM. The major problems considered were as follows: slope stability of embankments, modeling erosion and seepage, use of the phreatic surface level to ascertain the validity of centrifuge modeling, and the effects of compaction and weathering on a tailings embankment. This report summarizes the results of the four test series conducted at University of Cambridge and Sandia National Laboratories. A review of prior centrifuge applications to mining problems is included. Consideration is given to future centrifuge application to mining problems in both soil and rock mechanics.

Jan 1, 1989

By Richard J. Bielicki

This Bureau of Mines study estimates the number of major pieces of coal- mining equipment that will be required to produce 950 million tons of marketable coal in 1980 and 1.2 billion tons in 1985. The coal tonnages were projected in the intermediate coal supply scenario of Project Independence Blueprint (PIB). The equipment projections were determined by consideration of historical trends and by evaluation of information from equipment manufacturers and mining companies. The ability of the manufacturers to meet the projected equipment demands was also determined. It was concluded that equipment supply offers no presently discernible constraint to mining 1.2 billion tons of coal in 1985. A shortfall in projected production for the intervening years, however, is probable owing to anticipated shortages of draglines.

Jan 1, 1976

By Richard A. Busch

Inadequate engineering design criteria for coal refuse embankments has allowed hazardous impoundment structures in coal mining areas to be created. A necessary first step to develop adequate design criteria is the determina¬tion of basic, respresentative physical property data on the materials that constitute typical refuse embankments. An extensive field and laboratory program was undertaken by the Federal Bureau of Mines. Much physical property data was generated. Additonal petrographic analysis and large scale triaxial compression testing was performed by others. The data presented here should aid in establishing design parameters for coal refuse embankments

Jan 1, 1974

By James D. Noll, Jon A. Hummer, Shawn E. Vanderslice, Aleksandar D. Bugarski, George H. Jr. Schnakenberg, Steven E. Mischler, Larry D. Patts

The National Institute for Occupational Safety and Health designed and conducted a study in an underground metal mine to assess the effects of selected diesel emissions control technologies on the concentrations of diesel particulate matter and gases in underground mine air. The control technologies studied included diesel particulate filter (DPF) systems, filtration system with disposable filter elements, diesel oxidation catalytic converter, and biodiesel blends. Each technology was tested on a mining vehicle operated in an isolated area of an underground mine supplied with fresh air. These isolated zone tests allowed for the operation of vehicles under conditions and over duty cycles that closely mimic actual duty cycles of production equipment. The DPF systems reduced the elemental carbon (EC) concentrations in mine air between 88% and 99%. The same systems reduced total particulate matter (TPM) concentrations in mine air by approximately 75%. The biodiesel blends B20 and B50 caused a reduction in the EC concentrations of 26% and 48%, respectively. Those blends also reduced TPM concentrations by 9% and 24%, respectively. The use of #1 diesel fuel reduced EC concentration by 13% compared to #2 diesel fuel. An increase in nitrogen dioxide concentration of up to two times was seen when platinum-catalyzed DPF systems were tested.

Jan 5, 2006

As part of the United States Department of the Interior, Bureau of Mines Health and Safety Research Program, Walter C. McCrone Associates, Incorporated has examined 71 samples of airborne mine dusts using the techniques of x-ray diffraction, electron microprobe analysis and light microscopy. This report details the procedures which were used in this work and documents the results which were obtained.

Jan 1, 2011

By Richard L. Sanford

This report summarizes the results of the development of a Directory of Computer Programs Applicable to U.S. Mining Practices and Problems. The Directory includes a sampling of computer usage in operating and manufacturing companies, consulting firms, computer companies, research organizations, universities, and various U.S. government agencies. References to computer applications throughout the mining industry are presented as well as comments on the availability of programs to interested organizations or individuals.

Jan 1, 1977

By T. M. Ruff, W. G. McCoy, M. J. Beus, S. Iverson, W. Hasz

Technology to enhance safety during mine hoisting has been developed by researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health. Assessment of current hoisting technology suggests that monitoring conveyance position and load directly from the skip or cage top offers several significant safety advantages. Wireless data transmission schemes and a package consisting of sensors, batteries, and a charger mounted on the wire rope and skip have been developed. A state-of-the-art automated hoisting test facility was constructed to test the concept in a controlled laboratory setting. Field tests in a fill-size shaft are underway.

By H. F. Yancey

Traditionally the Pacific Northwest has relied on hydroelectric power, which has been both abundant and cheap. However, comparatively few hydroelectric sites capable of providing low-cost power remain, therefore the need for supplemental thermal generation, perhaps within the next decade, is generally recognized. Based on the present cost and availability of competing fuels, coal seems to be the logical choice for projected thermal power plants. Power companies and public utilities have become interested in establishing reserves of coal for future use. One deposit explored in 1958-59 lies in southern Thurston and northern Lewis Counties, Wash., near Centralia. Drilling, totaling 22,700 feet, proved the existence of 70 million tons of strippable coal--an ample reserve for the projected power plant. The coal, like most others and particularly those of Washington and Oregon, when mined in full seam section by mechanical methods, would require cleaning to make it suitable for use. The amount and nature of the impurities in this coal dictated a thorough investigation of its cleaning characteristics to establish economic factors and to insure proper preparation-plant design. Therefore, arrangements were made through a cooperative agreement to conduct such work at the Seattle Coal Research Laboratory of the Bureau of Mines. This report describes that investigation. The results are of interest primarily in connection with the utilization of this particular deposit, but some of the information developed is applicable to other deposits of low-rank coals in the West, because the impurities in these coals differ greatly in behavior from those generally associated with the higher rank coals of the Appalachian field.

Jan 1, 1961

By Alla D. Mah

The heat of formation of scandium sesquioxide (Sc203) has not been measured previously, and existing values for gallium sesquioxide (Ga203) are subject to large uncertainties. As a consequence, thermodynamic calculations involving these oxides hare lacked scientific exactness. This paper reports newly determined values of the heats of formation of gallium and scandium sesquioxides at 298.15° K., by combustion calorimetry. The corresponding free energies of formation are derived from heat and entropy data.

Jan 1, 1962

By John E. Urosek, Dennis A. Beiter, William J. Francart

In This Chapter [Designing bleeder systems Examining and maintaining bleeder systems Evaluating bleeder system effectiveness] INTRODUCTION Bleeder systems are that part of the mine ventilation network used to ventilate pillared areas in underground coal mines. Pillared areas are those in which pillars have been wholly or partially removed, including the areas where coal has been extracted by longwall mining. Bleeder systems protect miners from the hazards associated with methane and other gases, dusts and fumes, and oxygen deficiency that may occur in these mined-out areas. Effective bleeder systems control the air passing through the area and continuously dilute and move any methane-air mixtures and other gases, dusts, and fumes from the worked-out area away from active workings and into a return air course or to the surface of the mine. A bleeder system includes the pillared area (including the internal airflow paths), bleeder entries, bleeder connections, and all associated ventilation control devices that control the air passing through the pillared area. Bleeder entries are special air courses designed and maintained as part of the mine ventilation system. [This chapter focuses on the design, examination, maintenance, and evaluation of bleeder systems in underground coal mines.] The history of coal mine explosions in the United States is a reminder of the importance of adequate ventilation. Some of those disasters were the result of inadequately ventilated pillared areas. The importance of developing bleeder systems to ventilate these pillared areas and evaluating the bleeder system’s effectiveness is reflected in present-day federal regulations. For more information on bleeder systems, see Tisdale [1996] and Urosek and Francart [2002].

Jan 6, 2006

Safety rules for installing and using electrical equipment in and about coal mines covered in this information circular supersede those previously included in Bureau of Mines Bulletin 514, issued in 1952. This revision brings these rules up to date and more nearly in line with present operating and safety practices in the industry. The rules are intended to supplement existing Federal and State regulations, and no provision shall be construed to oppose or supersede any provisions of the Federal Mine Safety Codes, the Federal Coal Mine Safety Act, or the mining laws of any State. The rules were designed to permit progress, such as application of new or improved materials and equipment or use of new practices where these materials, equipment, or practices retain or improve the level of safety established by these requirements. It is hoped that they will fill the need for a concise edition for mine electricians and electrical engineers, especially those who do not have ready access to more detailed rules or codes.

Jan 1, 1964

By Katherine A. Margolis

Refuge Chamber Expectations Training was created by a multidisciplinary team at the National Institute for Occupational Safety and Health (NIOSH) to inform miners of what to expect psychologically and physically if it became necessary to use a refuge chamber in a mine emergency. The presentation can be used either for one large group or for individual miners. The training is a multimedia Adobe Flash presentation containing pictures, audio, video, and interviews with miners who have used a refuge chamber in an emergency. It must be run on a computer with Adobe Flash Player installed (refer to the computer system requirements section).

Oct 1, 2009

Safety rules for installing and using electrical equipment in and about coal mines covered in this information circular supersede those previously included in Bureau of Mines Bulletin 514, issued in 1952. This revision brings these rules up to data and more nearly in line with present operating and safety practices in the industry. The, rules are intended to supplement existing existing Federal and State regulations, and no provision shall be construed to oppose or supersede any provisions of the Federal Mine Safety Codes, the Federal Coal Mine Safety Act, or the mining laws of any State. The rules were designed to permit progress, such as application of new or improved materials and equipment or use of new practices where these materials, equipment or practices retain or improve the level of safety established by these requirements. It is hoped that they will fill the need for a concise edition for mine electricians and electrical engineers, especially those who do not have ready access to more detailed rules or codes.

Jan 1, 1964

By William F. Hahn

The Bureau Of Mines recognized the desireability of illuminating working places in trona mines. This report describes two illumination system designs, their demonstration and evaluation on a Jeffrey 120HR continuous mining machine in an active working trona mine in Wyoming.

Jan 1, 1980

By Thomas E. Lobb, Harry C. Verakis

Significant progress has been made in the reduction of serious injuries and fatalities resulting from mine blasting operations. Despite the progress, injuries and fatalities continue to occur. A leading cause of injuries and fatalities from blasting continues to be inadequate blast area security. Even though significant improvements in technology have been made, insuring adequate blast area security remains a challenge and requires constant vigilance. The advances in technology have created safer blasting products and have improved productivity and economics by enabling large, more efficient and effective blasts. However, as blasts grow larger in size, the complexity of adequately securing the blast area increases even more. Periodically the basic fundamentals involved in blasting safety should be reviewed, particularly for securing a blast site regardless of the size of the planned blast. Factors such as flyrock and toxic fumes must be taken into account to insure the safety of persons and property from the results of a blast. This paper examines the factors related to injuries due to inadequate blasting shelters and blast area security, and identifies mitigation techniques. The key concepts are: (a) accurate determination of the bounds of the blast area, (b) clearing employees from the blast area, (c) effective access control, (d) use of adequate blasting shelters, (e) efficient communications, and (f) training. Fundamentals are reviewed with an emphasis on analyzing task elements and identifying root causes for selected blasting accidents. Mitigating techniques are presented along with discussions and examples.

By John R. Bartels

This U.S. Bureau of Mines report describes the development, system by system evaluation, and preliminary surface testing of a flywheel-powered shuttle car (FPSC). The use of a self-contained flywheel-power source has the potential to eliminate the numerous safety and routing problems associated with tethered mobile equipment. An alternative to conventional power cable systems was developed consisting of the world's fIrst seven-rotor stacked flywheel system capable of storing 6 kW·h of energy at 16,700 rpm. Numerous interdependent systems were necessary for successful interfacing with a conventional shuttle car. Each of these systems was evaluated and tested individually. Finally, the entire shuttle car was surface tested. The tests indicated that the flywheel energy system can function and operate a shuttle car. The economics of the system and the design of required support systems were not addressed in the project.

Jan 1, 1991

By E. D. Gardner

This is one of a series of paper's being published by the Bureau of Mines on placer mining; it is written as a supplement to Information Circular 6788, "Placer Mining in the Western United States, Part III", by E. D. Gardner and C. H. Johnson which was published in February 1935. Since Information Circular 6788 was written (1933), considerable advance has been made in the technique of mining placer gravels with power shovels and draglines. Although new washing plants continue to be built in accordance with untried designs the trend of new installations is toward proved equipment. A substantial number of plants are now being operated successfully (1937).

Jan 1, 1938

By Fred C. Turin, Jasinder S. Jaspal, Alan G. Mayton, William J. Wiehagen

Dump site injuries occur in all major mineral industries. Working in elevated areas near an edge is a common hazard for operators of off-highway mobile mining equipment. In this Information Circular (IC), serious injuries involving haulage trucks working at dump sites are examined for the period 1988 to 1997. Data were acquired from injury reports gathered by the Mine Safety and Health Administration (MSHA). The IC is organized into three sections. The first presents an overview of the frequency and severity of injuries. The second analyzes injury characteristics using MSHA-defined data fields and author-defined injury classifications. Key findings are discussed in the third section. In summary, 370 serious injuries were identified that involved trucks at dump sites, of which 26 were fatalities. Although haulage truck activities at dump sites resulted in a small proportion of the total number of injuries at surface mines, these injuries were much more likely to result in death or significant amounts of lost time than most other surface mine injuries. These findings support the belief that haulage truck activities at dump sites are worthy of continued study by those interested in improving the health and safety of workers at surface mines.

Jan 3, 2001