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By Kathleen Kowalski-Trakofler, Edward Barrett

Problem: It is estimated that 5 to 10 arc flash explosions occur in electric equipment every day in the United States. In the mining industry the largest single injury category of electrical injuries are caused by non-contact electrical arcs. Method: This investigation progressed in two phases: (a) 836 Mine Safety and Health Administration (MSHA) reports of electric arcing incidents that occurred over a period of 11 years were reviewed, and (b) personal interviews were conducted with 32 individuals. A theoretical Safe Job Performance Model guided the study. Results: Behavioral dimensions were identified and included the effect of worker experience, judgment and decision-making ability, behavioral and organizational controls, and safety culture. Summary: The National Institute for Occupational Safety and Health (NIOSH) conducted an investigation of behavioral components associated with arc flash incidents and developed recommendations for interventions based on findings. Impact on Industry: This study fills a vacuum in electrical training with a focus on the organizational and behavioral aspects of arc flash incidents. There search is cross-cutting in its scope, in that the results apply not only to mining and construction, but many other industries employing electricians. Although the majority of mine electrical injuries are the results of burns from electrical arcs, few miners are aware that such a hazard exists. A safety training program, which includes a video and an instructor's discussion guide, was developed for electricians based on this study's findings. “Arc Flash Awareness” was released in 2007 (DHHS NIOSH PublicationNo.2007-116D) and is available through1-800 CDC-INFO. Phone:1-800232-4636 or email cdcinfo@cdc.gov. It is also available from MSHA at MSHADistribution@dol.gov or 304-256-3257 (DVD-576). Private industry is producing Portuguese and Spanish language translations.

By E. H. Denny

A most interesting safety record has been made by the Colorado Fuel and Iron Co. s. Robinson ho. 1 mine located at Walsen, Cola. Mr. J. L. McBrayer has been superintendent of the Robinson No. 1 and 2 mines for the past 2 1/2 years, and Mr. David Muir has been foreman of the Robinson No. 1 mine since June, 1913. The last fatal accident at Robinson No. 1 mine occurred on July 27, 1915, and the tonnage produced at this mine since July 28, 1915, has been as follows:.

Jan 1, 1929

By Daryl E. Radcliffe

This report describes an instrument system developed by the Bureau of Mines to continuously monitor and record changes in roof displacement during underground mining activity. The instrument consists of a single-wire extensometer coupled to a mechanical-drive chart recorder mounted in an aluminum frame installed in the roof. The unit is small and simple to install and meets safety requirements for use in underground coal mines.

Jan 1, 1977

By Wilbert T. Malenka

In its search for a highly productive mining system for anthracite beds pitching from 100 to 200, where conventional mobile equipment cannot be used) the Bureau initiated a longwall project by introducing a shearer drum cutter loader of European origin. Because of the undulating nature of the roof and floor and changing bed thicknesses, the machine proved inflexible and extra work was required in lifting bottom coal and blasting top coal.

Jan 1, 1966

By N. S. Dalal, X. Shi

It has been known for more than a decade that vanadium (V) stimulates the oxidation of NADH by plasma membranes (1) but the underlying mechanism is still not fully understood. This effect has been attributed to a membrane-associated NADH-dependent vanadium (V) oxidoreductase (1). Subsequent studies suggest that vanadium ( V) can accept an electron from fiavoprotein dehydrogenase that oxidizes NADH (2). The phenomenon ofNAD(P)H oxidation coupled to vanadium(V) reduction has also been demonstrated in other biological systems (3-6). A recent electron spin resonance (ESR) study from our laboratory reported on the accumulation of vanadium (IV) duringthe reduction ofvanadate (vanadium(V)) by the ftavoenzymes glutathione reductase (GSSG-R),4 lipoyl dehydrogenase, and ferredoxin-NADP+ oxidoreductase in the presence of NAD(P)H (7). It was concluded therein (7) that these ftavoenzymes function as NAD(P)H-dependent vanadium(V) reductases. More recently, however, Liochev and Fridovich (8) have argued that the ESR data (7) do not demonstrate that the investigated fiavoenzymes act as vanadate reductases. They suggest an alternative mechanism in which the fiavoenzyme simply serves as a generator ofsuperoxide (02) radical, which acts as a propagator of the radical chain reaction leading to NAD(P)H oxidation (9, 10), as summarized below:

Nov 1, 1995

Provide the U.S. mining industry with the means to measure and control exhaust emissions of diesel engines used in underground mines. Approach Diesel research is divided into four primary areas: exhaust aerosol measurement, particulate control, gaseous emission control, and chemical and biological characterizition of particulate matter. Diesel research is frequently cosponsored by industry; collaborative research ventures between industry, academia, other government agencies, and the Bureau arc common. Diesel research at the Bureau is conducted in the diesel engine research facility at the Bureau?s Twin Cities Research Center (TCRC). This facility is a state-of-the-art laboratory capable of performing emissions testing, exhaust control evaluations, and safety tests. Background Exposure of mine workers to airborne contaminants from diesel engine exhaust is potentially harmful. The National Institute for Occupational Safety and Health has recommended that whole diesel exhaust be regarded as "a potential occupational carcinogen" and that ?reductions in exposure to diesel exhaust in the workplace would reduce the risk." The U.S. Mine Safely and Health Administration (MSHA) convened an Advisory Committee on Standards and Regulations for Diesel-Powered Equipment and is beginning to implement its recommendations, which cover health, safety, and certification and approval issues surrounding the use of diesels underground. In January 1992, MSHA published an advance notice of proposed rulemaking to regulate diesel particulate matter in underground mines.

Jan 1, 1992

By A. Z. Dimitroff, A. C. Moschetti

An improvised rock- dust disseminator, consisting of a 10-gallon galvanized metal milk can that dispenses rock dust in return air currents by the injection of compressed air has reduced the float dust explosion hazards at the Koehler coal mine, Koehler, N. Mex.

Jun 23, 1964

By Edward F. Divers

The Bureau of Mines recently tested a sideboard device that is designed to act as an extension of conventional brattice, thus improving face ventilation of developing room-and-pillar-type coal mining. In these laboratory tests, an 8-foot-long rigid sideboard was mounted vertically along the left fender of a full-scale-model ripper-type continuous mining machine, rising to the mine roof to provide an air seal. It extended from the auger support frame pivot point outby along the fender. A novel water spray manifold was used to form an air seal between the sideboard and brattice. Tests showed improvement in face ventilation with the prototype device, and also demonstrated that water sprays can form an effective air seal over a fairly wide pressure range. Based on this preliminary study, subsequent improvements may make the sideboard concept much more effective, thus affording a simple, inexpensive technique to improve the effectiveness of face ventilation.

Jan 1, 1979

By A. Z. Dimitroff

An improvised rock- dust disseminator, consisting of a 10-gallon galvanized metal milk can that dispenses rock dust in return air currents by the injection of compressed air has reduced the float dust explosion hazards at the Koehler coal mine, Koehler, N. Mex.

Jan 1, 1965

By A. Z. Dimitroff

An improvised rock-dust disseminator, consisting of a 10-gallon galvanized metal milk can that dispenses rock dust in return air currents by the injection of compressed air has reduced the float dust explosion hazards at the Koehler coal mine, Koehler, N. Mex.

Jan 1, 1965

By Frank E. Cash

The iron-ore ranges in the Lake Superior district are the liarquette in Michigan, Menominee and Gogebic in Michigan end Wisconsin, and the Vermilion, Mesabi, and Cuvuna in Minnesota. These ranges produce about 85 percent of the iron ore mined in the United States. Accident experience in connection with this production is better than that of the regions producing the remaining 15 percent. Production and shipments vary slightly from year to year but closely approximate each other over a period of years. During the 4-year period 1940 to 1943, inclusive, 323,667,599 long tons of iron ore was shipped from the Lake Superior district.4/ Michigan and Wisconsin shipped 65,386,608 tons, or 20.2 percent of the total, and employed approximately 15,000 men; Minnesota shipped 258,280,991 tons, or 79.8 percent of the total, and employed approximately 10,000 men. The tons produced per man employed is much, greater in Minnesota than in Michigan and Wisconsin owing to the large open-cut production in Minnesota.

Jan 1, 1945

By W. M. Deaton

[Knowledge of the ten?erat~rre to wkich n gas ullder3atur~ted xith re- srplc t to water vapor may be cooled before the water p?f 11 3egin to condense 8 is desirable .and frec-uently iq neceTsarp in nWy resenrch md industri~J activities. This tenperrture, the dew point, i s 2 nrrticulnrly innortmt factor in high-pressure gas transmission, PS water cox?-ensate any interfere i with the flow of gos in the line. Sonetimes this interfexnce is due only to the yresence of the liquid water. At other tfncs, under certain condi- tions of pressure and teriperature, the cogdense;? water cn!nhines with the 93 to farm solid .y2: hydrctes. These solid coar~ouncis ma:/ ccllect in sufficient quantit;. to rehce materially the c~xrying cap.citg of the pipe line or ever, to ply thc line coimletelp.]

Jan 1, 1938

By W. M. Deaton

[Knowledge of the ten?erat~rre to wkich n gas ullder3atur~ted xith re- srplc t to water vapor may be cooled before the water p?f 11 3egin to condense 8 is desirable .and frec-uently iq neceTsarp in nWy resenrch c~d industri~J activities. This tenperrture, the dew point, i s 2 nrrticulnrly innortmt factor in high-pressure gas transmission, PS water cox?-ensate any interfere i with the flow of gos in the line. Sonetimes this interfexnce is due only to the yresence of the liquid water. At other tfncs, under certain condi- tions of pressure and teriperature, the cogdense;? water cn!nhines with the 93 to farm solid .y2: hydrctes. These solid coar~ouncis ma:/ ccllect in sufficient quantit;. to rehce materially the c~xrying cap.citg of the pipe line or ever, to ply thc line coimletelp. ]

Jan 1, 1938

By L. B. Berger

In this investigation, the ampoule type of carbon-monoxide (CO) detector which is manufactured under license of U. S. Patent 1,644,014 (October 4, 1927) was tested for sensitivity and reliability. This detector was devised primarily for examining the air of manholes and sewers for possible dangerous contamination with CO before workman enter those places, but dine to the simplicity of the device it may have a more general usage for examination of atmospheres which are known or suspected to be contaminated with CO. Some of the suggested uses are the examination of the air in garages, tunnels, mines, around blast furnaces, gas plants, and in the home.

Jan 1, 1930

By Richard J. Bielicki

Poor mixing of methane and air at coal mine working faces causes fluctuating methane concentrations. If these fluctuations are large enough, methane levels can periodically exceed safe limits, even though the time average methane concentration may be satisfactory. Concentration fluctuations measured underground can result both from variations in methane emission rate and poor mixing. The present paper reports on a statistical analysis of fluctuations at a constant methane emission rate, that is, on fluctuations due only to poor mixing. A full-scale model of a working face was used. Both peak heights and elapsed times between peaks were evaluated. Good mixing was indicated by normal, Poisson, and exponential distributions while poor or incomplete mixing was indicated by log-normal or gamma distributions.

Jan 1, 1974

By Alla D. Mah

No experimental heat-of-formation value has been reported in the literature for cerium sesquioxide. The heat of formation of bismuth sesquioxide has not been determined in recent years, and the older value was subject to large uncertainty. Accordingly, the heats of combustion of cerium sesquioxide and bismuth metal were measured by the Federal Bureau of Mines. The heats of formation were: ?H°298.15 = -427.01 ± 0.70 kcal. /mole for cerium sesquioxide and ?H°298.15 = -137.16 ± 0.30 kcal./mole for bismuth sesquioxide. The free energy of formation was estimated for cerium sesquioxide and accurately calculated for bismuth sesquioxide. The data were compared with values in the literature.

Jan 1, 1961

By Leonard Obert

The various underground rooms in the Bureau of Mines Oil-Shale mine, Rifle, Colo., have been open for periods ranging from 3 to 5 years. During this time 3 roof falls have occurred; 1 was induced, and the other 2 were unintentional. The three roof falls are described in this report. Two causative factors are discussed -a time-dependent deterioration of the roof rock and an unfavorable system of jointing that occurred in the strata overlying the present roof horizon. Irrespective of cause, the operating life of any stoping area would have been short com-pared with the life of the roof (1 to 4 in the most unfavorable instance), if a high-production system of mining had been employed. The report is concluded with several recommendations that should be considered in planning future mining operations.

Jan 1, 1958

By Jack E. Fraley

Magnesium oxysulfate cement has been specially formulated as a sealant in underground coal mines for reducing sloughing of shale roofs and coal ribs, for reducing air losses through block stoppings, for constructing sprayed stop-pings over approved jute cloth or metal lath, and for reducing combustibility of polyurethane foam. A standard spray machine (Mining Enforcement and Safety Administration (MESA) approved) was used for the underground testing. Our research shows that a 1/2-inch coating reduces shale and coal sloughing, reduces air losses through block stoppings, and prevents fire propagation through a metal tunnel lined with polyurethane foam. During the underground tests, excess mixing water was used to improve pumping the slurry to the spray nozzle. This was later found to increase shrinkage cracks in the cured coatings. Controlling excess water is important to an acceptable coating.

Jan 1, 1976

By Richard J. Kline

The underground mining industry is presently using the fluid network analyzer and digital computer to analyze ventilation systems. The availability of the digital computer and ventilation programs to mining companies has escalated its use, permitting the design and modification of new or existing mine ventilation systems to be projected completely and thoroughly with consistent precision. Because the analog computer has been analyzing ventilation systems accurately for many years, a comparison of the analog and digital methods was warranted. This report summarizes a detailed comparison for one mine, based on parallel analyses by the two computer systems.

Jan 1, 1972

By D. C. Fleck

This report describes a method of using sodium for reducing titanium tetrachloride, developed at Boulder City, Nev., as part of the Federal Bureau of Mines effort to improve the extractive metallurgy of titanium. Finely divided titanium metal, titanium lower chlorides, or a mixture thereof was produced in a continuous operation at temperatures between 105° and 205° C. by the reaction of molten sodium and vaporized titanium tetra-chloride in an agitated bed of finely divided inert solids (powdered sodium chloride or the reaction products). Composition of the product was controlled by varying the relative quantities of sodium and titanium tetrachloride used. A description of the operations and analytical data of the reaction products are given.

Jan 1, 1960