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By John R. Shattuck

As a part of the general chromite investigation in California designed to aid In the production of chromite during the recent war emergency, the Bureau of Mines explored the Coggins property in Siskiyou County, Work by the Bureau in cooperation with the Federal Geological Survey began in October 1942 and was concluded in March 1943. This report presents a brief history of the mine, outlines the physical features of the district, describes the deposits) and explains the work completed by the Bureau of Mines, Table 1 shows the analysis of diamond drill-hole samples. The logs of drill holes are in the appendix.

Jan 1, 1949

By David E. Siskind

The Bureau of Mines has studied the fracturing produced in the vicinity of large-diameter blastholes in Lithonia granite. Cores were taken from the vicinity of AN-FO production blasts and examined using a total of seven laboratory and field measurement techniques to delineate zones of damage and evaluate the effectiveness of the seven diagnostic tests for fracture-state determination. Laboratory measurements of acoustic pulse velocity, porosity, permeability, compressive strength, and Young's modulus indicated the extent of fracturing with the acoustic techniques providing the best means of distinguishing between fractured and unfractured core. A severely fractured zone was found to extend approximately 25 inches (64 cm) from the center of the 6-l/2-inch blastholes, equivalent to 8 blast-hole radii. A second zone, characterized by a lesser degree of fracturing extended from 25 to 45 inches (64 to 114 cm) or 8-to l4-blasthole radii. Beyond 45 inches (114 cm) the rock was undamaged.

Jan 1, 1974

By W. H. Ode, W. A. Selvig

Low-temperature distillation tests at 200°, 350°, and 500° C. were made on a subbituminous coal from Boulder County, Colo., and a subbituminous coal from Weld County Colo., in connection with a survey of carbonizing properties of American coals 4/ and investigations of their chemical and physical properties. 5/ The coal represented by the sample from Weld County was reported to give off combustible volatile matter at unusually low temperatures when placed on a fuel bed. The yields of tar and oil and the composition of the as from this coal, as obtained in the distillation tests, did not confirm this report. These yields and the gas composition of the Weld County coal differed but little from those obtained from the coal from Boulder County. Both coals yielded tar and gas in amounts considered to be normal for coals of their rank.

May 1, 1937

By J. Dean Warner

In 1984, as part of a project to evaluate Alaskan occurrences of certain critical and strategic minerals, the Bureau of Mines investigated a columbium-bearing regolith on upper Idaho Gulch, near Tofty, AK. The regolith is derived from weathering of a dolomitic marble and consists mostly of iron oxide minerals with accessory apatite, zircon, xenotime, rutile, monazite, and the columbium minerals aeschynite, columbite, and ilmenorutile. Two regolith lenses contain 340,000 lb of columbium resources at an average grade of 0.07 pct. Calculated composite concentrates from two regolith samples (approximately 200 lb each) contained 53 and 57 pct of the columbium at grades of 0.97 and 0.86 pct, respectively. In each case the grade could be improved to 1.1 pct Cb with a sacrifice of 9-pct recovery. The regolith's mineralogy, trace-element geochemistry, and similarity to descriptions of other columbium-enriched regoliths suggest that the underlying marble may be a carbonatite. The lack of associated alkalic igneous rocks and the stratiform nature of the regolith, however, may be interpreted as evidence for sedimentary origin of the marble. The marble and regolith are a lode source for some of the minerals in the Idaho Gulch placer deposit.

Jan 1, 1986

By Todd M. Ruff

Researchers at the National Institute for Occupational Safety and Health (NIOSH), Spokane Research Laboratory, are investigating technology and methods to monitor the blind areas around large haulage equipment used in surface mines. On average, six fatalities a year can be attributed to equipment colliding with other vehicles or pedestrian workers, or backing over the edge of a dump point. Several off-the-shelf technologies exist for monitoring areas that an equipment operator cannot see from the cab, including radar, video cameras, and radio signal detection systems. NIOSH researchers have tested many of these systems on large dump trucks both at their test facility and at surface mines. This article discusses the technologies available for this application and their effectiveness in detecting objects near an off-highway dump truck. Also, guidance is presented for mine safety personnel who are planning to evaluate collision warning systems or cameras on their haulage equipment. Available Technology Over the past few years, the number and types of systems available for monitoring the blind areas around heavy equipment have increased. Systems marketed for the automotive and recreational vehicle industries have been around for a while. Small video cameras can be found

By W. E. Wallace, P. S. Mike, C. A. Hill, V. Vallyathan, M. J. Keane

Respirable quartz duet and a kaolin clay dust have been found to be of comparable cytotoxic potential in vitro on a specific surface area basis (Wallace, et a1,1985), despite the distinctly different potentials of quartz and clay for causing pneumoconiosis or pulmonary fibrosis (Sheers, 1984). A respired particle depositing in a respiratory bronchiole or alveolus will contact a pulmonary surfactant hypophase, of which a primary component is diacyl glycerophosphorylcholine, or diacyl lecithin (DPL) (Clements, et al, 1970). Several studies have found that adsorption of such surfactant suppresses in vitro cytotoxic effects of quartz dust (Marks, 1957). Subsequent phagocytosis and digestion by a macrophage may remove the coating, restoring cytotoxic potential and initiating disease processes (Iles, 1979). Adsorption of dipalmitoyl lecithin (DPL) from emulsion in physiologic saline by respirable sized quartz dust and kaolin dusts, and consequent diminution of the dusts' hemolytic and macrophage cytotoxic potential have been reported (Wallace, et al, 1985). This report presents additional data on the cell-free in vitro phospholipase A2 enzymatic digestion of dipalmitoyl lecithin adsorbed on a quartz and a kaolin respirable sized dust (Wallace, et al, 1988) to investigate mineral specific differences in the rates of digestion and of consequent restoration of dust membranolytic potential. Respirable crystalline alpha quarts used was eighty percent smaller than 5 micorometer aerodynamic diameter with a nitrogen adsorption specific surface area of 3.97 m2/g. Respirable kaolin dust was ninety percent smaller than 5 micrometer diameter and had a specific surface area of 13.25 m2/g.

Jan 1, 1988

By N. S. Dalal, Xianglin Shi

"Electron spin resonance (ESR) spin trapping experiments have been carried out to investigate the mechanism of sulfite oxidation em¬ploying 5,5-dimethyl-l-pyrroline-1-oxide (DMPO) as a spin trap. The results show that sulfite autoxidation, catalyzed by Mn(II), involves not only the SO-3 radicals but also the •OH radicals. An addition of H2 02 to the sulfite aqueous medium significantly increases the •OH radical formation. This result provides new clues to the chemical mechanism of the sulfite oxidation and the sulfite toxicity.INTRODUCTIONStudies of the oxidation of the sulfite (SO 2-/3) ions under various conditions are of high current interest because excessive exposure to sulfite is toxic and the origin of this toxicity seems to involve sulfite oxidative pathways [1]. An important fact is that human exposure to sulfite is on the increase [1,2]. Some of the increase in the sulfite exposure is linked to the fact that SO2 is a major air pollutant [2] and in aqueous media SO2 exists in equilibrium with SO2-/3. In addition, beverages and foods are common sources of sulfite intake. For example, sulfite is used extensively in the wine industry as an inhibitor of yeasts and bacteria and is present in finished wines in concentrations up to 6 mM [1]. Sulfite is also often added to dehydrated fruits, vegetables and soups, as well as fruit juices and beer [1,3,4]. Because of these, the mean daily intake of sulfite from diet (in the United States) has been estimated to be between 0.0014 and 0.14 mM/kg body weight [1]. At such high levels, sulfite exposure can have toxic effects, such as the induction of an acute asthmatic state [5,6]. Sulfite also appears to have adverse genetic effects [7] and can act as a mutagen or comutagen [8] and a cocarcinogen [5,7-9]."

Jan 1, 1990

By W. W. Adams

"During the calendar year 1925 the Bureau of Mines received from the operators of several hundred mines and quarries complete accident records covering deaths, permanent disabilities, and “lost time” temporary injuries. Some of the companies, - those that participated in the National Safety Competition-also furnished information showing the number of man-hours of work performed during the year. With these two types of information it was possible to calculate the accident-frequency and accident-severity rates of the different plants. Complete and comparable reports of accidents and Man-hours of “exposure” were received from 34 underground metal mines, 59 underground coal mines, 15 underground mines producing other nonmetallic minerals, and 102 open quarries or open-pit mines. The figures in the table appended to this report show the accident severity rates and other data for each of the 34 underground metal mines and for the group as a whole. It is proposed to publish similar figures for the other classes of mines and quarries at an early date.The 34 metal mines listed in the table are situated in Arizona, Idaho, Kansas, Michigan, Minnesota, Missouri, New Jersey, New Mexico, Oklahoma, South Dakota., and Utah; they employed 5, 925 men, an average of 174 men per mine, including employees above-ground as well as underground. With but few exceptions, 50 men was the minimum number of employees in any mine. The total period of employment or “exposure” at the 34 mines was 14,612,607 man-hours, an average of 2,466 hours per man, or the equivalent of 308 work-days of eight hours for each employee. Accidents resulted in 15 fatalities, 9 permanent disabilities, and 1,950 temporary “lost time” injuries (causing disability exceeding remainder of shift). The fatal and nonfatal injuries represented 132,575 days of disability. Thus the accident frequency rate for the group was 135 accidents per million hours and the accident severity rate was 9.073 days lost per thousand hours of 1 “exposure”. The severity rates ranged from 0.227 to 88.653, while the ·range of the accident-frequency rates was from 16. 6 to 307 .4. In compiling the accident severity rates shown in the table, all accidents caused by explosives were weighted at twice the number of days actually lost, as one of the purposes of the National Safety Competition was to stress the prevention of accidents caused by explosives."

Sep 1, 1926

By B. M. Bench

This Bureau of Mines report describes photo lineaments obtained from stereoscopic examination of vertical aerial photographs and by the Ronchi grating study of aerial photoindex sheets. The photolineaments are compared with the trends of oriented fracture systems procured by measuring the compass direction of joints in bedrock. The relative reliability of the methods is shown, and the results are presented in graphical, tabular, and written form. Analyses of field measurements of strikes of bedrock joints in the project area indicate for the most part two intersecting sets of major joints oriented N 76° W -N 15° E, and N 57° W -N 27° E. The analyses of lineaments determined by stereoscopic examination of aerial photographs show dominant trends of lineament zones of weakness to be an average of N 65° W -N 20° E. Analysis of lineaments found by Ronchi grid viewing of aerial photoindex sheets indicate dominant trends of N 70° W -N 27° E. The three methods give similar findings and verify the work of previous authors. The Ronchi grid method is a useful guide, but it cannot be substituted for the two more painstaking methods.

Jan 1, 1977

By A. G. Smelley

As part of research conducted in its mission to effect pollution abatement, the Bureau of Mines, U. S. Department of the Interior, is developing a dewatering technique that allows for disposal of phosphatic clay wastes, for reuse of water now lost with clays, and for reclamation of mined land. The technique utilizes a high-molecular-weightnonionic polyethylene oxide polymer (PEO) that has the ability to flocculate and dewater phosphatic clay wastes. A synergistic flocculation study was made to determine whether a portion of PEO could be replaced by other reagents. Several groups of reagents were tested: (1) those that increased the zeta potential of the phosphatic clay wastes; (2) those capable of hydrogen bonding; and (3) those which flocculated the phosphatic clay waste. Reduction in PEO consumption occurred only with addition of those reagents able to flocculate the slime. The use of natural guar gums resulted in a lower PEO requirement and also yielded a dewatered product of higher solids content, 43 to 45 percent, versus 33 to 35 percent obtained with PEO alone.

Jan 1, 1980

By William J. Campbell

The Federal Bureau of Mines provided five test materials--amosite, short-and long-fiber chrysotile, crocidolite, and nonfibrous tremo1ite--to the National Institute of Environmental Health Sciences (NIEHS) for studies on the biological effects of orally ingested asbestos-related materials. An inter-agency agreement between the Bureau and NIEHS made possible this program to characterize these test materials. The Bureau in turn received support through contracts with the Ontario Research Foundation for the milling of amosite and crocidolite, and with the University of Maryland for microscopic measurements. The five test materials, which were supplied in quantities of 960 to 1,200 pounds each, were characterized by chemical-instrumental analysis for elemental composition, surface area, density, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, mineralogy, and particle size analyses. Particle size distributions were emphasized because of the current theories relating adverse biological effects to length-width characteristics of durable elongated particles.

Jan 1, 1980

By Lucia Kuizon

In 1986 and 1987, at the request of the U.S. Forest Service, the U.S. Bureau of Mines studied the Diamond Peak area comprising 183,000 acres in the Challis and Targhee National Forests in order to evaluate its identified mineral resources. More than 3,000 mining claims were located in three mining districts between the years 1882 and 1986. Approximately 230 mining claims in and the 150 claims adjacent to the study area were current in 1986, when Bureau of Land Management mining records were researched for this study. A total of 1,270 samples were collected from these sites (30 were for alluvial placer). Results of the investigation help determine the suitability of the study area for inclusion into the National Wilderness Preservation System. Lead-, silver-, zinc-, copper-, and gold-bearing minerals occur as veins and replacement bodies in shear and fault zones in Precambrian and Paleozoic calcareous Sedimentary rocks that have been complexly folded and faulted. Total production from the three mining districts in the study area was more than 150,000 tons of ore between 1901 and 1982. Approximately 11,600 tons of subeconomic resources consisting of lead, silver, zinc and copper were identified within the area. Over 37,500 tons of lead and zinc subeconomic resources were identified just outside the area. In addition, lead-, silver-, and zinc-mineral resources were identified at 4 mines within 2 miles of the study area. Iron mineral resources were also identified just outside the area.

Jan 1, 1991

By Sean Gallagher, William S. Marras, Alan S. Litsky, Deborah Burr

This paper describes a comparison of the fatigue failure responses of older versus younger lumbar spine cadaver motion segment specimens. These specimens were repeatedly subjected to loads simulating those experienced by the spine in lifting a 9 kg load in different torso flexion postures (0, 22.5, and 45 degrees of flexion). An older sample of 36 motion segments (average age 81 years + 8 SD) is compared with a younger sample of 18 motion segments (average age: 47 years + 9 SD) with respect to the number of cycles to failure and results of survival analyses evaluating the effects of flexion and bone mineral content with and without the younger data set. Compared to the older sample of spines, the younger sample exhibited many more cycles to fatigue failure in all the torso flexion conditions (10020 versus 8267 average cycles to failure in 0 degrees flexion, 7124 versus 3262 in 22.5 degrees flexion, and 3229 versus 263 cycles to failure in 45 degrees flexion). The increased cycles to failure in young specimens is likely due to the increased bone mineral content (BMC) in younger motion segments (30.7 g + 11.1 g per motion segment versus 27.8 + 9.4 g). Cox regression analyses modeling both flexion effects and BMC indicate that betas are similar when just older spines are modeled and when younger specimens are included in the analysis. Betas for survival analysis models with and without younger specimens generally show little change for flexion (2.716 versus 2.756 for 22.5 degrees [0 degrees referent], 3.926 versus 3.380 for 45 degrees [0 degrees referent]). Bone mineral content shows a similar protective effect in both models (Betas: -0.127 versus -0.087). Overall, comparison of the models indicate that risk ratios are similar for 22.5 degrees flexion, slightly increased for 45 degrees flexion and slightly more protective influence predicted for BMC in the combined sample versus the older sample alone.

By Ivan F. Avery

DOMEST1C production of carbon black in 1963, remained at about the same level as in 1962. Carbon black produced by the furnace process increased 2 percent to 1,880 million pounds in 1963 and accounted for 91 percent of the total output. Channel black production continued to decline and was 14 percent less than a year ago. Shipments during 1963 totaled 2,098 million pounds, a 1 percent increase for the year. An increase of 88 million pounds in domestic sales was partially offset by a decrease of 72 million pounds in carbon black exports. Total value of carbon black production in 1963 was $148 million. The average value per pound was 7.18 cents or 0.12 cent per pound more than in 1962.

Jan 1, 1964

By P. L. Woolf

An investigation was conducted to evaluate the use of a formcoke as the total fuel in the Bureau of Mines experimental blast furnace. The formcoke performed very satisfactorily, and comparisons made with a metallurgical coke showed that the performance with the formcoke was somewhat superior under the experimental conditions used.

Jan 1, 1966

By Thomas M. Barczak

The transverse loading requirement for stoppings as specified in the current Code of Federal Regulations is 39 psf. This measure is based on physical testing of a freestanding wall in accordance with ASTM E 72 specifications, where the dominant parameter is the tensile strength of the sealant. A new protocol based on arching has been developed to determine the true transverse load capacity of stoppings. Arching is achieved by the restraint of the stopping against the mine roof and floor, whereby compressive forces are developed within the wall. A laboratory procedure using the NIOSH Mine Roof Simulator (MRS) to simulate rigid-arching of stoppings was developed and verified through full-scale in-mine tests. Using this protocol, a systematic study of the design parameters that affect arching capability in block stoppings was conducted. The study included a theoretical assessment of arching and development of design formulations that can accurately define the transverse load capacity of various stopping constructions under various loading conditions. This approach should lead to a safer mine environment by matching the transverse load capabilities of the stopping design to the requirements in the mine to ensure proper ventilation control is maintained.

Jan 1, 2005

By Jacob N. Frank

A factorially designed, hydraulic fragmentation experiment using a high-pressure water jet was conducted on concrete blocks. Three levels of pressure, standoff distance, and impact angle and two levels of traverse time and surface condition were used. Three variables were measured: depth of penetration, volume of material removed, and width of slot. Three stepwise linear regression equations were developed from the jet parameters and the physical properties of the concrete. The three basic equations, describing the significant jet parameters and physical properties, were developed into 15 predictor equations, five for each variable investigated. Direct regression equations were also developed for each variable investigated to show the result of increasing or decreasing each significant variable. Energy efficiencies were developed for the experiment and for each significant factorial variable.

Jan 1, 1971

By H. Schultz

Urban refuse that was mechanically separated at the U S Bureau of Mines pilot plant in College Park, Md., was successfully evaluated for its fuel values using standard coal analysis methods. Analyses performed on refuse samples taken from five sample points included moisture, ash, sulfur, chlorine, and heating value. It was recommended that characterization of the combustible portion of urban refuse by standard coal analysis procedures should be widely adopted.

Jan 1, 1975

By Arnulf P. Hagen

This project was designed to explore the suitability of using fluorinated inorganic materials as solvents for the in situ mining of thin seamed, heavily overburdened coal; to build a data base for the selection of an inorganic solvent for use for coal cleaning; to determine if fluorinated solvents will reduce the organic and inorganic sulfur contents of the coal, as well as to lower the ash content. The coal samples have been combined with pure solvent, as well as with aqueous solutions at atmospheric pressure and at increased pressure. The increased pressure experiments are important since they duplicate the conditions anticipated for an in situ cleaning and mining operation. Trifluoroacetic, difluorphosphoric (phosphorodifluoroidic), and trifluoromethanesulfonic acids have been found to be effective for the cleaning of high sulfur, high ash coal at 300°C and at atmospheric pressure. At pressures up to 20,000 psi the effectiveness of these reagents is not decreased.

Jan 1, 1983

By Victor E. Kral

"SUMMARYFollowing a magnetometer survey on the McCoy iron deposit, a trenching and drilling program was carried out by the Bureau of Mines in August 1944.This deposit is 32.3 miles southwest of Battle Mountain in the McCoy Mining District, Lander County, Nevada, and lies on the east flank of the Fish Creek Mountains at an altitude of 5,400 feet, about 1 1/2 miles south of the gold camp of McCoy.Total production from the deposit has been 400 tons of magnetite, mined by hand and shipped to the west coast for ship's ballast.Bureau drilled two holes to a total depth of 92 feet and excavated 12 feet of trenches. Both holes were drilled in the same ore body and engineered magnetite ore 14 and 11 feet thick. Trenching was used successfully to show the lateral limits of the ore.Magnetite ore bodies were found to occur as replacements of a limestone bed in quartzite. They outcrop near and parallel to the exposure of a diorite entrusting that forms a long westward-trending ridge. Although magnetic outcrops can be traced for 5,000 feet trenching definitely proved the ore bodies to be disconnected to have little or no lateral extent beyond their outcrops. Only two ore bodies more than 10 feet thick were found; one of these is the inaccessible to and the other was drilled by the Bureau."

Jan 1, 1947