Search Documents

By H. Kenworthy

The objective of this research was to develop methods and determine conditions under which metallic sulfides with lower boiling points than sphalerite may be removed from zinc sulfide concentrates by volatilization. A higher percentage of extraction of lead, cadmium, and germanium than is common in current practice was sought. The investigation, conducted by the Metallurgical Branch of the Minerals Technology Division, Region VI, showed that, under proper conditions, it is possible to remove over 90 percent of the lead, cadmium and germanium as an enriched sublimate. The uses of lead, and cadmium to a lesser extent, are well-known. Although germanium was discovered in 1886 by C. Winkler, commercial use has been achieved only in recent years. The amount consumed per manufacturer unit is so small that the price of germanium may still be quoted by the gram. The electronic industries have been the chief consumer of this semiconductor. Germanium is sold largely to the fabricator as a dioxide for reduction to metal and subsequent processing into wafers for use in diode and triode electronic tubes. Extensive research at Purdue University during World War II led to the first practical use of germanium.

Jan 1, 1952

By W. P. Yant

Public interest in atmospheric pollution by automobile exhaust gas and in the ventilation of vehicular tunnels makes it desirable to ascertain whether the use of modern automobile fuels is tending to change the amount and composition of the products of combustion. The Bureau of Mines, in cooperation with the Ethyl Gasoline corporation4, has completed a series of testis to determine whether any significant difference exists in the carbon monoxide content of the exhaust gas produced by an internal-combustion engine when its fuel is changed from straight gasoline to the same gasoline containing Ethyl fluid whose active ingredient is tetraethyl lead. In the tests data was sought relative to the composition and mount of the gas produced by ordinary comparatively low-compression motors as well as by higher-compression motors in which distinct detonation occurred with straight gasoline, but which operated without detonation when using the same gasoline containing tetraethyl lead.

Jan 1, 1929

By John L. Reuss

A laboratory study was conducted by the Bureau of Mines to investigate the technical feasibility of decomposing hydrous magnesium chlorides by using a steam pyrohydrolysis technique. This procedure consisted of injecting steam into the atmosphere of a decomposition furnace containing samples of hydrous magnesium chloride and determining the rate of hydrolysis by measuring the rate of chloride evolution. The variables investigated were temperature, amount of water vapor in the decomposition atmosphere, and hydration stage of magnesium chloride. The application of steam was shown to accelerate both the rate and completeness of magnesium chloride decomposition reactions. For example, when magnesium chloride hexahydrate is exposed to a furnace temperature of 600' C in an air atmosphere for 20 minutes, the decomposition is 37 percent. Under identical conditions in a steam atmosphere, the decomposition is in excess of 70 percent. The magnesium oxide produced by the steam pyrohydrolysis of magnesium chloride dihydrate at 800° C contained 98 percent magnesium oxide. Based on magnesium oxide composition, this is equivalent to that of burned magnesite produced at temperatures in excess of 1,300° C. To demonstrate the quality of the product on a practical basis, metal reduction tests have shown it to be equivalent to reagent-grade magnesium oxide as a carbothermic reduction feed material.

Jan 1, 1974

Measure tattling in cemented backfill when installation of bore-hole extensometers is not feasible. Problem To evaluate the amount of load that backfill carries during pillar recovery, information about how much the backfill settles after placement is often required. However, the composition of some backfills makes them difficult to drill and the installation of borehole extensometers almost impossible. Approach Bureau researchers have developed a vertical fill extensometer that can be cast in place as a stope is being filled. It consists of a baseplate, sections of steel pipe enclosed in loosely coupled polyvinyl chloride (PVC) pipe, and a top anchor assembly that contains a displacement transducer (fig. 1).

Jan 1, 1990

By D. Harrington, C. W. Owings

"The belief is now fairly general among the coal-mining people of the United States that one of the most effective methods of preventing wide-spread coalmine .explosions is that of introducing rock-dust into coal mines to reduce the inflammability or explosibility of dusts found on mine surfaces. Notwithstanding this belief it is improbable that even a small fraction of 1 per cent of the coal mines of the United States are at all adequately protected by rock-dust; in a survey made in the summer, and fall of 1927 it was found that but 463 out of more than 7,000 operating bituminous and lignitic coal mines were using rock-dust at all, and that few if any of the 463 were fully or adequately protected by rock-dusting.Inspections of a large number of mines through the United States by Bureau of Mines safety division field men have failed to reveal a single adequately rock-dusted mine, Yet there is no doubt that many of the owners and operators believed their properties to be fully protected by rock-dust against the much-feared hazard of widespread explosion. Two of the most disastrous explosions of recent years occurred at properties where the owners were definitely of the belief that the rock-dusting done had made the mines immune to widespread explosion involving coal-dust. In both instances it was found that although some rock-dusting had been done, the mines were more nearly 1 per cent than 100 per cent rock-dusted.This condition as to inefficiency or insufficiency of rock-dusting in the coal mines of the United States is almost universal, and unless our mining men awaken to its, dangers, the disaster record of the coal-mining industry is much more likely to become worse than better. During the fiscal year ended June 30, 1928, the attention of the safety division of the United States Bureau of Mines was called to. 22 explosions With 320 fatalities in bituminous coal mines of the United States; and of the 22 explosions there were 10 with 258 fatalities in mines that were listed as having used rock-dust; upon investigation it was found that as usual the rock-dusting had been anything but comprehensive or adequate. It is probable that in a very few instances last year the relatively small amount of rock-dusting stopped the .extension of the explosion and thus prevented further expansion of the death list. In general, however, the explosions occurred in a part of the mine that had not been rock-dusted - and right here is the crux of the failure or probable failure of present-day rock-dusting in the United States, There should be no part of any bituminous or coal mine in which all of the exposed surfaces (roof, ribs, and floor) have not been thoroughly rock-dusted and kept thoroughly rock-dusted. In other words, all exposed surfaces of all accessible places in bituminous and lignitic coal mines should be kept covered with rock-dust so that the combined rock-dust coal-dust mixture at all times and in all places has less than 35 or 40 per cent combustible matter, The only exception to this rule is that surfaces which are wet (and this does not mean merely damp) need not be rock-dusted. However, a mine opening may have several inches of water on the floor and yet have much explosive dust on the ribs and roof above the water; in such places the ribs and roof should be kept rock-dusted, irrespective of the wetness of the floor."

Nov 1, 1928

The coal deposits in Alaska occur in several major coal fields or basins. The deposits underlie about a quarter of the state, an area larger than Montana. Approximately 60 percent of the coal is bituminous and 40 percent is subbituminous. Less than one percent is lignite or anthracite. Although known coal reserves are estimated at only 6.1 billion tons (about 1.25 percent of U.S. reserves), estimates place the hypothetical reserves at 5.5 trillion tons and the identified reserves at 170 billion tons. The differences are due to limited exploration programs within the state. Conditions affecting mining and reclamation are unique to Alaska because of its extreme northern latitude. For example, permafrost occurs in about 75 percent of the state; tundra vegetation occupies vast treeless regions; and the climate is characterized by extremely cold winter weather and a short summer season. In addition, hydrologic conditions are considerably different from those in other states; major streams fed by silt-laden glacial melt water contain greater concentrations of natural sediment than the effluent discharge limits permitted by federal regulations. Also, some coal field locations are subject to potentially high seismic risk. These factors make coal mining and reclamation in Alaska more difficult than in other states. Alaska's program to regulate surface coal mining was approved May 2,1983. The Abandoned Mine Lands program was approved December 23,1983.

Jan 1, 1992

By R. E. Brown

The objective of this Bureau of Mines study was a laboratory-scale evaluation of the sodium sulfate refining process for removing copper from molten ferrous scrap. Maximum copper removal is achieved in carbon-saturated melts at 1,300° C. Low carbon concentrations and higher temperatures result in a less efficient copper removal and an increased sulfur concentration in the iron. Sodium sulfate refining significantly lowers the concentration of aluminum, manganese, and silicon; however, the copper removal efficiency is adversely affected by the presence of manganese and silicon. Compared with other reagents tested, sodium sulfide-forming slags were found to be the most suitable for both copper removal and sulfur control. The sulfur content of the refined iron was higher in tests conducted in acid-type refractory crucibles. Earlier studies showed that tin, a significant metallurgical impurity, is not removed by the sulfate process. During the present investigation, results showed that chlorination, using organic solid sources of chlorine, reduced the tin concentration to acceptable levels in molten iron.

Jan 1, 1975

Provide a simple and effective means of measuring mining-induced pressure changes in coal mine roof and pillars. Approach Develop a reliable, easy to fabricate and install borehole instrument which measures mining-induced pressure changes in pillars and in the mine roof. Ground pressures are monitored through use of aluminum platens coupled with d copper flat jack. How It Works The Bureau's instrument measures mining-induced pressure changes by transmitting strata pressure through the aluminum platens to an oil-filled borehole platened flat jack (BPF). Pressure in the flat jack is displayed on a gage located outside of the borehole. The instrument is in-stalled in the borehole by inflating the flat jack using a hand-held hydraulic pump. In addition, the platens have been designed to allow up to three BPFs to be installed in a single borehole, thus permitting pressure change measurements in more than one direction from a single borehole. Installation pressure is calculated on the basis of the estimated pressure exerted by the overburden and the percent of recovery after intial mining has

Jan 1, 1986

By R. C. Annear

This report describes open, sublevel, and shrinkage stoping at the Greenwood mine, operated by Inland Steel-Co. The iron ore mine is in Marquette County, Mich., about 6 miles southwest of Ishpeming (fig. 1). The Greenwood is one of three active underground hard-ore mines on the Marquette range, the others being the Cliffs-Shaft and the Champion mines. The operation reflects an achievement in exploiting small, difficult-to-mine hard-ore bodies lying beneath a 200-foot overburden of glacial drift, which is partly water bearing. This report can indicate only briefly the efforts of personnel in overcoming adverse conditions in mining more than 2 million tons of ore, 80 percent of which was in lump form, for open-hearth production of steel. Significant data presented include descriptions of the principal mining methods employed, sublevel and shrinkage stoping; percent aged mining costs for the entire year 1957, covering both direct mining costs and general expenses; and performance records in units of labor, power, and supplies.

Jan 1, 1960

By J. E. Tiffany, Z. C. Gaugler

"In presenting this list of permissible explosives and blasting devices, the Bureau of Mines desires to call attention to pages 20 and 25 outlining the conditions in use under which, and only under which, the explosive or blasting device is permissible.In view of a recent publication recounting trade practice favoring the use of a blasting device without stemming, particular emphasis is placed upon condition 4 on page 20 and condition 2 on page 25. An explosive or a blasting device enumerated in the permissible lists of this Bureau is not permissible in use unless it is properly confined with clay or other incombustible stemming.PERMISSIBLE EXPLOSIVES TESTED UNDER SCHEDULE 17CAn active list of permissible explosives was published in October 1938 as part of Bureau of Mines Report of Investigations 3421, under the title ""Active List of Permissible Explosives and. Blasting Devices Approved Prior to June 30, 1938."" This list included 191 brand names.Changes in the list that have been authorized to June 30, 1939, placed 56 additional brands of permissible explosives on the active permissible list as a result of tests, changes in brand names, or transfer from the inactive list. Fifty-seven permissible explosives were transferred from the active to the inactive list. The brand names of four explosives were rescinded curing the year. The present list contains 18G brand names. The brand names of the Permissible explosives placed on the active list are as follows:"

Sep 1, 1939

By R. A. Keaens, L. C. IlsLey

For the purpose of this paper a junction box is defined as " a fused switch, inclosed in an explosion-proof compartment, provided with a ready means of connecting or disconnecting a trailing cable without exterior arcing." Junction boxes are intended for use 'at the end of trailing cables and are usually placed outby the last open break through in a coal mine. Where it is not safe to supply current through nips or a trolley, junction boxes suitably spaced along an entry permit tramming and movement of machines with safety, although not with any considerable speed. Junction boxes serve a threefold purpose: (1) They prevent dangerous arcing at the outby end of trailing cables; (2) they afford a safe, practical means of fusing or otherwise protecting the trailing cable; and (3) they provide an efficient means of transmitting power from the power circuit to the trailing cable. The first purpose is the most important from a safety standpoint. Dangerous arcing-that is, arcing capable of igniting gas-frequently takes place where trailing cab1c.s are attached to the power circuit. At either 250 or 500 volts only a very small arc is required to ignite mine gas. The usual method of connecting the trailing cable to the power circuit by cable nips or trolley taps does not make a good electrical connection; hence arcing may be expected at any time. Furthermore, junction boxes eliminate the personal hazard attendant upon the use of trolley taps by removing the possibility of accidental contact with trolley hooks or wire and the liability to injury due to manipulation of the device. In the general scheme of mine ventilation it is assumed that gas will not accumulate where junction boxes are placed, an assumption based on the normal operation of the ventilating system. In many

Jan 1, 1929

By John P. Gooch

The Bureau of Mines wrote a computer program which calculates the saturation curves and condensation characteristics of gaseous mixtures consisting of binary organic vapor and air. The program employs an algorithm which assumes an equilibrium mechanism for condensation, and the degree of fractionation obtained is predicted on the basis of relative volatility. The program incorporates a feature which allows the user to examine the fractionation resulting from condensation as a function of the size of the temperature increments over which condensation is assumed to occur. If a single. temperature interval between the dewpoint of the mixture and the outlet temperature of the condenser is assumed for the calculation, the results obtained will be those resulting from a single equilibrium condensation. If the condensation is assumed to occur over a number of temperature increments, the results obtained will approach those predicted by the Rayleigh equation as the magnitude of the temperature increments approaches zero. The results from calculations performed on vapor mixtures from organic heavy liquid solutions used in beneficiating potash and brucite ores are presented. The liquids are solutions of dibromomethane in trichloroethylene or perchloroethylene. The results show the degree of liquid recovery which is possible by cooling mixtures of organic vapor in air. Compositions of the vapor range from 10 to 95 percent air, and assumed condenser exit temperatures range from 110° to 50° F.

Jan 1, 1971

By Oliver Bowles

This paper is the fourth of the current series issued by the Bureau of Mines on lime- plant problems . It is hoped that the information presented in these reports will develop sufficient interest among lime- plant operators to prompt them to discuss with the Bureau their own experiences , for it is believed by such an interchange of ideas conclusions will be reached that will be of practical benefit to the entire industry . Much valuable information has been obtained from replies to the papers already issued , but a more general response is greatly desired . It is hoped that many operators will contribute additions to the information on transportation systems now at hand by answering the questions on the final page .

Mar 1, 1923

By Raghoottma S. Pandurangi, Mohindar S. Seehra

"The interaction of amorphous 1ilica particles with several hydrogen bonding agents (H2O, C2H5OH, C7H2NO) was investigated by monitoring the changes in the bulk and surface IR vibrational modes of silica using photoacoustic spectroscopy. It is argued that the intensity of the silanol band at 3747 cm-1 provides (an inverse) quantitative measure of the interaction or surface groups, along with the shift in the broad hydroxyl band, the interaction following the order C7H2NO > C2H5OH > H2O. Index Headings: Silica; Surface vibrational modes; Photoacoustic spectroscopy; Hydrogen bonding agents.INTRODUCTIONThe use of m spectroscopy to study the adsorption on solid surfaces is well documented in the literature.1 2 For example, hydroxylation of a clean silica surface results in the formation of the free silanol group Si-OH, with a sharp IR band near 3747 cm-1• Further hydroxylation produces a broad band near 3500 cm-1, which is believed to result from various hydrogen-bonded silanol bands leading to a multilayered surface structure of few nm.3-5 Earlier studies had indicated a relationship between the surface silanol band and various chemical activities of silica such as cytotoxicity, 7- 9 catalysis, 10-12 and others.13 Recent studies from our group14-in which the intensity of the silanol band and cytotoxicity of silica, heat-treated at various temperatures up to 1095°C, were investigated have provided a strong correlation between cytotoxicity and intensity of the silanol band.Coating of silica by PVPNO (polyvinyl-2-pyridine N-oxide with the empirical formula C7H8NO), a strong hydrogen bonding agent, is known to reduce the cytotoxicity of silica, presumably by chemically blocking the silanol groups from phospholipids.15 This interaction of the hydrogen bonding agents with the silica can be studied by m spectroscopy, and Knozinger16 and Rouxlet and Semples11 have used transmission m spectroscopy to study the effect of various chemicals on the surface IR modes of silica. However, one of the major disadvantages of transmission IR spectroscopy is that the sample preparation (grinding and mixing with KBr and pelletizing) usually distorts the surface modes (see, e.g., Ref. 14) and there is always a doubt about the effect of the sample preparation on the measured properties. In recent years, photoacoustic (PA) spectroscopy has become the technique of choice for studying the IR spectra of samples in their natural state, since no sample preparation is necessary.18•19 Moreover, according to a recent paper, 20 the relative intensity of the surface modes in PA spectroscopy of silica particles is much higher than that in transmission FT-IR spectroscopy. Consequently PA spectroscopy is ideal for studying the surface chemistry. In this work, we have used PA spectroscopy to investigate the interaction of three hydrogen bonding agents (C7H8NO, C2H50H, and H20) with the silica surface by monitoring changes in the surface m modes. Our results show that the surface IR modes get perturbed to a larger extent than the bulk IR modes in interaction with the hydrogen bonding agents. Moreover, whereas in the earlier studies, the shift of the broad silanol band near 3500 cm-1 was used as a measure of the interaction with hydrogen bonding agents,16•17 here we show that the relative decrease in the intensity of the sharp silanol band near 3747 cm-1 also serves as a quantitative parameter for the relative surface coverage and surface modification. Details of this work are given below."

Jan 1, 1990

By S. R. B. Cooke, J. Bruce Clemmer, F. P. Diener

"The limestone deposit utilized by one of the plants of the Universal Atlas Cement Co. is covered in part by a stratum of cherty limestone. If this overlying deposit could be utilized by removing the excess of chert economically, quarry costs could be reduced and the amount of rock economically available would be increased greatly. On account of the distribution of flint and limestone, a product fairly free of flint can be obtained until the quarry face is about 50 or 55 feet high. As the face is worked farther back into the hill, the comparatively clean stone is overlain with a constantly increasing amount of high-flint limestone. If this flint remained with the limestone, there would be a prohititively high silica ratio in the finished cement; if the flinty layer were removed as overburden a very large tonnage would be handled and much good stone lost. Consequently it was felt that means should be devised for separating the flint from the limestone after it reaches the plant.The investigation was undertaken by the Mississippi Valley Experiment Station of the United States Bureau of Mines in cooperation with the Universal Atlas Cement Co. and the Missouri School of Mines and Metallurgy, Rolla, Mo.CONSIDERATION OF PROCESSESMany schemes for the separation of Minerals are based on differences in the specific gravities of the minerals to be separated. In this case the flint has a specific gravity of approximately 2.62 while the limestone averages about 2.70. This differential is not large enough to permit separation by any method based on specific gravity. Furthermore, all the limestone particles in any given sample are not alike; usually about 10 percent of them have a specific gravity the same as, or lower than, the flint."

Mar 1, 1935

By Burke Cartwright, S. F. Ravitz, Lloyd R. Michaels

This method is similar to the reduction of dolomite by ferrosilicon, in that it does not require the direct use of electrical energy; like ferrosilicon, the calcium carbide must be produced in an electric furnace, so that the reducing agent in both processes may be considered in some respects as “stored” electrical energy. The reduction of magnesium chloride by calcium carbide is exothermic, takes place rapidly at ordinary pressure and at relatively low temperatures, and can be carried out in ordinary steel equipment, whereas the reduction of dolomite by ferrosilicon and the carbothermic reduction of magnesium oxide are endothermic, require high temperatures, and present serious problems with respect to materials of construction. Because of its apparent simplicity and other advantages, the Bureau of Mines has briefly investigated the reduction of magnesium chloride by calcium carbide. Published data on the reduction of magnesium chloride by calcium carbide are meager. Matignon states that reduction is fairly rapid at 1,200º C. Matsuura claims that magnesium chloride is not reduced by calcium carbide at atmospheric pressure and 800º C; however, by keeping the pressure under 10 mm. of mercury he was able to obtain small globules of magnesium at 800º C.

Mar 1, 1947

By John J. Henn

Two lime sinter processes for recovering alumina from clay, the double-leach process and the single-leach process, are evaluated in this Bureau of Mines report. In both processes, clay and limestone are mixed and sintered to form calcium aluminate from which alumina is extracted as sodium aluminate by leaching with a dilute solution of sodium carbonate. The pregnant liquor is desilicated, then carbonated to precipitate alumina trihydrate which is recovered and calcined to a,-alumina. The fixed capital costs for plants producing 1,000 tons per day of alumina are $85 million for the double-leach process and $86 million for the single-leach process based on a Marshall and Stevens chemical equipment index of 240.0. Because plant locations are variable with respect to the proximity of clay and limestone deposits, a nomograph is included to determine operating costs at various delivered costs of clay and limestone. For plants at which the delivered cost of clay containing 30 percent A1203 is $2 per ton and the delivered cost of limestone is $1 per ton, the operating costs are $81.04 and $89.87 per ton of alumina for the double-leach process and single-leach pro-cess, respectively.

Jan 1, 1969

By N. S. Dalal, X. Shi

"This study reports a new property of the important NAD(P)H-dependent flavoenzymes, glutathione reductase, lipoyl dehydrogenase and ferredoxin- NADP oxidoreductase, that can catalyze a one electron reduction of metal ions such as chromium(VI) and vanadium(V). During the enzymatic reduction process, molecular oxygen is reduced to H2O 2 , which reacts with the reduced metal complexes to generate hydroxyl radicals. Since the hydroxyl radicals have been suggested to play an important role in Cr(VI) toxicity, this study provides a basis for a recent observation that Cr(VI) mutagenesis is strongly oxygen dependent. These results also point to an enzymatic pathway for the metabolism of some metal ions and concomitant generation of hydroxyl radicals. l. INTRODUCTIONThe purpose of this communication is to report that some important NAD(P)H-dependent flavoenzymes (glutathione reductase, lipoyl dehydrogenase and ferredoxin-NADP+ oxidoreductase) can catalyze one electron reduction of metal ions such as chromium(VI) and vanadium(V) and simultaneously reduce molecular oxygen to generate Hi02 and, eventually, the ""OH radical. This finding is significant because (i) the known substrates for the flavoenzymes are organic species and not metal ions, and (ii) the report on the enzymatic formation of the ""OH radical provides a new pathway for understanding the mechanism of genotoxicity of some non-ferrous metal ions. For example, it has been suggested that OH radical is likely to be the major species responsible for Cr(VI) genotoxicity [1-5). The 'OH radical is generated through the reaction of Cr(V) complexes with cellular Hi02 [4,5]. Cr(V) itself is known to be generated from Cr(VI) in various biological systems, in particular, microsomes [ 6), mitochondria [7] and mitochondrial electron transfer chain complexes [8]. However, no specific enzyme responsible for the Cr(V) generation has been identified except possibly glutathione reductase [4]. In this study we have used ESR and spin trapping techniques to show that the flavoenzymes can generate Cr(V) and provide a catalytic redox cycle for 'OH formation in such reactions. Herein we present our results on Cr(VI) and summarize those on other systems. Correspondence address: N.S."

Jan 1, 1990

By Robert J. Anderso

Few elements have received more attention and developed greater interest in the last ten years than titanium. The substantially pure metal has been din...ie. cult to isolate, and so far has been little employed oommercially, but the use af alloys and chemical compounds of titanium has increased markedly in recent years. The earlier attempts at preparing pure titanium resulted in various impure forme which, from their metallic appearance, were always mistaken for the metal. Hunter in 1910 isolated pure titanium by the reduction of titanium tetrachloride with sodium. This brief statement is issued by the Bureau of Mines in response to numerous inquiries which have been received concerning titanium. More complete in. formation on the metal may be had by consulting the referenpes appended. The Literature is voluminous and only the more important references are Riven. It has been drawn upon freely in preparing this report; also information was supplied by M. g. Hunter, Arthur Braid, M 1. Schmid, C. M. Johnson, N. B. Hoffman, and de Courny Browne. The pioneer investigator in titanium is A. IL Rossi.

Oct 1, 1922

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.