Search Documents

Real economic growth for 1988 may fall short of the 3.3% projected by the U.S. Department of Commerce in August 1988 be-cause the summer drought and intense heat in many areas curtailed output more severely than expected. The economy grew at an average annual rate of 3.0% for the first three quarters of the year, slowing in the second and third quarters. Export growth, which occurred even as the dollar edged up com-pared with other industrial country currencies, was an important factor in the expansion. Notable gains were posted in sales of machinery, computers, aircraft, chemicals, and telecommunications equipment. Imports increased, but not as much as exports, and the U.S. trade position was still much improved from that of 1987. Personal consumption expenditures grew slightly faster than the economy as a whole. Purchases of consumer durables showed notable strength in the first half of 1988, but slowed down in the third quarter. [ ] Despite the moderate rise in interest rates, business spending for new plant and equipment also rose and contributed to 1988 gross national product (GNP) growth. Both new business investment and export demand spurred orders for U.S.-made machine tools. Orders for machine tools for the first 8 months of 1988 were almost triple those for the corresponding period in 1987.

Jan 1, 1988

By Robert C. Hickman, Xavier B. Starnes

"The general location of the Kentucky, Fluorspar District and the Moore Hill fault area are shown in figure 1. An engineer3/ the Bureau of Mines visited the district in July 1942 and reported on the Moore Hill fault system. Subsequently the Bureau explored the Summers, Pepperbox, McCune, Eagle-Watson, Henry Watson, Davenport, Felix Tyner, and Eagle-Wring prop¬erties by core drilling. These properties and the principal faults are shown on figures 2 and 3.Collaboration of the Federal Geological Survey4/ was of great benefit, particularly in mapping the properties, determining the stratigraphy, and furnishing information on that and other geologic factors.Fluorite was noted as early as 1818 near Shawneetown in southern Illinois.5/ In 1835 an attempt was made to work deposit in Crittenden County, Kentucky, but interest centered chiefly upon the galena found with the fluorite. The first shipments of fluorspar from Kentucky wore made in 1373 from the Yandell mine of Crittendon County.6/ It is not known when the first work on the Moore Hill fault was done, but it seems probable that the Cullen-Eagle and Nancy Hanks were being ,worked in 1900. Gravel spar was found on the surface at the Two Brothers mine in 1904,7/ and the main shaft was started in 1914; work also began at .the Davenport in 1914, and in 1917 the Eagle-Watson was in production. A shaft was gunk on the Pepperbox in 1918, and in 1922 fluorspar was found and work was started on the Summers property. In 1924 work began at the McCune, Felix Tyner, Eagle-Wring, and probably the Hicks properties.No Good approximate record of production from each property on the Moore Hill fault system is obtainable, but an estimate based upon all data available is as follows:"

Sep 1, 1946

By A. C. Fieldner

ONE of the important functions of the Bureau of Mines is the, analysis of coal from every coal-mining State and Alaska. These analyses are being published for use of Government officials and the public. In connection with analytical data showing composition and quality of coals of the States, consumers, Producers, and the general public will be interested in a brief description of the geologic structure of the coal basins, typical mining conditions in the several districts, and the principal economic data of the industry. These publications have therefore heel) designed to include such features to present concisely the principal facts regarding occurrence, reserves, duality, characteristics, production, and uses of coals of each producing State.

Jan 1, 1952

By M. M. Ayoub

With a return to coal as a major energy source for many companies, more emphasis is being placed on recovery of coal from areas that were formally considered uneconomical to mine. Increasing emphasis is being placed on production from low coal (seam height 48 inches or less) as high coal seams are depleated. Mining in restrictive spaces requires unusual work postures that can turn easy jobs into demanding ones. The objectives of this research were: (1) to evaluate the job demands associated with low coal mining, (2) to survey the anthropometry, strength, and aerobic capacity of low coal miners to determine if they differ from the U. S. population, and (3) to recommend, on the basis of available information, optimal job and work station design for low coal mining. This research effort was supported by the U. S. Bureau of Mines. The male and female anthropometry with the exception of weight and circumferential dimension, was quite similar to the comparison population. Back strength for male and female miners was significantly lower than the industrial worker population. This can be one of the contributing factors of low back problems in mining. Shoveling, timbering, and helpers tasks were physiologically demanding activities. However, due to the frequent stoppage of work, adequate rest was usually available. If work stoppage is corrected, then better work/rest schedules are essential.

Jan 1, 1981

By R. V. Ramani

This volume, the first of a six volume final report, provides an executive summary of the research and results carried out under a grant from the U. S. Bureau of Mines on underground coal mine ventilation. Under the project, a mine ventilation simulator was developed. Sensitivity of leakage and friction factors on the total quantity and pressure requirements was studied. The simulator was applied to a new mine under development, and to an operating mine, to demonstrate the usefulness of the simulator in ventilation planning and in evaluating proposed changes to existing ventilation system. The titles of the other volumes are as follows: Volume II: Mine Ventilation Network Theory Volume III: User's Manual for PSU/MVS Volume IV: Sensitivity of Leakage and Friction Factors Volume V: Application of PSU/MVS to Ventilation Planning of a New Mine Volume VI: Application of PSU/MVS to the Analysis of Modifications to Existing Ventilation Systems

Jan 1, 1977

By B. K. Cantrell, K. L. Rubow

"Two source apportionment techniques have been applied by the U.S. Bureau of Mines to aerosol measurements in diesel-equipped underground noncoal mines. The first technique is based on size-selective sampling and the premise that the diesel exhaust fraction of the aerosol is predominately submicrometer in size while the mineral dust fraction of the aerosol is mostly supermicrometer in size. The second technique, chemical mass balance (CMB) modeling, was used to referee the analysis of diesel and mineral dust aerosol concentrations with the size selective method.The size-distribution data were modeled using a lognormal regression to parameterize the submicrometer and supermicrometer fractions of the sampled aerosol and to estimate the mineral and diesel contributions to each. Using this analysis, 97 ± 2 pct of the submicrometer aerosol mass was attributable to diesel exhaust aerosol.The CMB analysis, applied to both fractions of the respirable mi11e aerosol, yielded the amount contributed to each by the diesel and dust aerosol sources. On the basis of this analysis, 94± 10 pct of the submicrometer fraction was diesel exhaust aerosol. As much as 20 pct of the diesel aerosol, however, was found in the supermicrometer fraction, requiring a correction of the submicrometer fraction results to account for the missing diesel mass. More accurate measurements will require a carbon-specific analysis of the aerosol.INTRODUCTION Measurement of the contribution of diesel exhaust to respirable aerosol in mine environments has become increasingly important because of current concerns over the occupational health effects resulting from exposure to diesel emissions. In response to this, the U.S. Bureau of Mines is developing and evaluating new sampling methods for measuring diesel aerosol in underground mines. Two such techniques are being studied by the Bureau, size selective sampling and CMB modeling. These techniques use measurable physical or chemical characteristics of a mine aerosol sample to infer the amount of diesel particulate material contained in the sample."

Mar 1, 1992

By N. E. Hanna

The current list of permissible explosives includes 124 different brands. Fifteen of these are gelatinous, and the rest are the more commonly used granular ammonium nitrate type. Their rates of detonation range from 1,300 to 5,600 meters per second, and the weights of 1-1/4 x 8-inch cartridges range from 86 to 244 grams. The list of permissible blasting devices includes 1 Cobra, 2 Hydrox, and 9 Cardox models. All of these devices are based on discharge of high-pressure gas from a pressurized shell in a shothole. INTRODUCTION To be approved for use in underground coal mines in the United States, explosives and blasting devices must pass certain schedule tests prescribed by the Bureau of Mines. The explosives listed here were tested under Schedule 1-G,3 which has since been replaced by Schedule 1-H;4 the blasting devices were tested under Schedule 26A.5

Jan 1, 1962

By P. J. Watson

The objective of this study was to prioritize the potential risks nuisance and biologically active dusts and fumes present in metal and nonmetal mines. This was accomplished by ranking numerical values derived from a matrix formula calculation that took into account dose, mine population, and sampling size. Data used in these calculations were obtained from the Mine Inspection Data Analysis System (MIDAS). The dusts determined to have the highest risk potential were quartz respirable particulates, mine dust, cristobalite respirable particulates, welding fume components, and nuisance respirable dust. Other dusts and fumes that were not ranked in this study, due to small sampling population, but which show a potential risk, include asbestos, talc, hydrogen cyanide, organic compound dusts, arsenic, metal dusts, and metal and nonmetal fumes.

Jan 1, 1987

By R. S. Dean

The original flotation reagents were certain oils selected for a combination of properties that occurred fortuitously. It was recognized quite early in the study of flotation mechanism that, in order to function, an oil must have an active group-one that differs from the remainder of the molecule in its affinity for water or the mineral particle. Wark4 gives credit for recognition of this elementary chemical principle to the senior author of this report.5 However, it was soon found that simple hydrocarbons could not be used as flotation reagents and that two of the functions, which were combined in the early flotation oils such as pine and eucalyptus, could be obtained in separate compounds and their relative intensity controlled to advantage. These two functions were called collecting and frothing.

Jan 1, 1944

By R. Larry Grayson

In the October 1998 issue of the Holmes Safety Association Bulletin, NIOSH authors Mark Stephenson and Carol Merry wrote the article Hearing loss among miners and measures to protect hearing, which focused on the extensiveness of hearing loss among miners and the use of hearing protection to prevent hearing loss. While the primary importance of engineering controls in preventing hearing loss was discussed, since miners do not generally have control over their work en­vironment or assignments, the article focused on the importance of consis­tent use of hearing protection. In this article, all aspects of a compre­hensive approach to the prevention of hearing loss in miners will be covered. The discussions will do the following: ? describe application of the hierarchy of controls in preventing hear­ing loss in miners, ? give an example for each type of control measure and its impact, ? explain the major provisions, be­yond the hierarchy of controls, of the recent NIOSH document en-titled Criteria for a Recommended Standard: Occupa­tional Noise Exposure, Revised Criteria 1998 relative to a hearing loss prevention program, and ? summarize important points on control of noise exposure for every miner to remember, equipment in most facets of operations. Miners are well aware of noisy areas in or around equipment, icluding extraction machinery such as draglines, power shovels, longwall shearers, and continuous mining machines; powered haulage equipment such as load-haul-dumps, shuttle cars, large trucks, and continuous haulage units; roof bolting machines; jackleg drills and stopers; auxiliary equipment such as compressors, fans, and pumps; size reduction equipment, etc. They are not well aware of the insidious nature of pro­gressive hearing loss, which is per­manent, but they are generally aware of what levels of noise are hazardous and what measures can be taken to reduce their personal noise exposure. Behaviorally, however, there are many reasons why miners choose not to use hearing protection faithfully.

Jan 1, 1998

By W. W. Adams, T. D. Lawrence

"The National Safety Competition conducted by the Bureau of Mines, United States Department of the Interior for the promotion of safety in mines and quarries, has just been closed for seventeenth consecutive year. Enrollment covered more plants than in any previous contest. Moreover, a larger volume of employment was represented than in the contests of previous years, and several new plants were enrolled for the first time. Six safety trophies are awarded annually in these competitions one to the leading plant in each of six groups. An anthracite, mine in Pennsylvania, a bituminous-coal mine in West Virginia, a metal mine in Tennessee, a nonmetal mine in Virginia an open-cut mine in Minnesota, and a quarry in Alabama won the 1941 trophies.To be eligible to win a trophy, a mine or quarry must have had at least least 25 men working under ground or in the pit for not loss than 100 days. The number of man-hours worked must total 30,000 or more. Mines or quarries having no accidents during the year are rated according to the number of man-hours worked. If there are no plants with accident-free records, the mines and quarries in each of the six groups are rated according to their accident-severity rates; the plant having, the lowest rate is declared the winner.The Sentinls of safety trophies presented to the winning mines and quarries in the six groups were donated by the Explosives Engineer magazine to promote safety in the mineral industry. They are held by the winning companies for 1 year or until won by other mines and quarries."

Jul 1, 1942

By T. A. Sullivan

Refining in a molten salt electrolyte was investigated as a means of recovering nickel containing less than 1 percent and preferably less than 0.2 percent cobalt from nickel products containing up to 5 percent cobalt. Electrolytic separation of nick and cobalt was accomplished in a molten KCl-LiCl-NiCl2 electrolyte. Nickel containing less than 0.10 percent cobalt was routinely prepared. Factors that influenced the transfer of cobalt to the refined product were the nickel concentration of the electrolyte, the cobalt concentration of the electrolyte, the ratio of nickel to cobalt in the electrolyte, and cathode current densities. A method of recovering the cobalt from the electrolyte was developed. The possibility of preparing high-purity nickel by this process was shown, as well as the preparation of various cobalt-nickel-tungsten alloys.

Jan 1, 1968

By Jerry B. F. Champlin

NIOSHAn accelerated testing procedure developed by the Bureau of Mines for evaluating commercially available corrosion inhibitors is described. Ultra-sonic agitation of the corrodent solutions and the hot-finished mild steel test coupons was used to evaluate the effects of several variables on the effectiveness of two corrosion inhibitors. Small changes in the weight of the test coupons in both controlled and inhibited corrodents, before and after exposure, affected the precision and accuracy of the results. Minute amounts of oxygen in the systems were found to be causing the relatively large deviations in the corrosion developed in the controlled tests. Microscopic examination of the test coupons revealed that both surface preparation and internal strains resulting from fabrication methods materially affect corrosion behavior.

Jan 1, 1965

By L. F. Willmott

The Bureau of Mines at Morgantown, W. Va., has been investigating, on a pilot plant scale, various methods of gasifying bituminous coal with oxygen and superheated steam to produce synthesis gas, as part of the broader program of finding new uses for coal. Differences in the pressure gasification methods used have depended on differences in the manner in which the pulverized coal is fed to the gasifier. One of the methods of feeding the coal that was investigated was the continuous, integrated coal-water slurry system. Goal and water were first mixed to produce a slurry; then the slurry was pumped through a heated coil. to evaporate the water fraction; the resulting steam was superheated, and some of it was separated so as to adjust the ratio of the residual steam to the coal fraction and make the resulting mixture suitable for partial combustion with oxygen in a pressure gasifier. Both before and during this reported3 developmental work it was necessary to make an extensive literature search into the technology of aqueous slurries in order to establish design criteria for the pilot plant and to correlate results of various phases of the work with that of other investigators, The pilot work coincided with the commercial development of a long-distance pipeline for the transportation of coal as a coal-water slurry, and this fact tended to broaden the scope of the pilot plant work and the extent of the literature search. This bibliography is the compilation of the material that was collected.

Jan 1, 1963

By R. C. Corey

GERMANIUM is an element that has come into widespread use in the electronics industry in recent, years. So far this increasing demand has been, met by ample supply: however, the future balance is uncertain, and the need has been recognized to discover additional domestic sources of germanium. This investigation was conducted to study the possibility of obtaining a potential supply of germanium from coal or coal ash. It has been known for some time that coal contains germanium; the discovery that By ash from coal-fired boilers often contains appreciably more germanium than the original coal suggested the possibility that coal ash might be an abundant and economical source of this element. In this study the concentration of germanium was determined in numerous samples of coal and ash. A number of miscellaneous waste materials also were examined in the course of the investigation; the results are reported as a matter of general interest. The methods and equipment employed are discussed in detail. Sample-preparation and analytical techniques are described in the appendix. Spectrographic analyses were made on a total of 639 samples, including coal, coal ash, slap ash from lignite and peat, wood ash, and various inorganic materials. Qualitative analyses were run on all samples, and quantitative determinations were made on those samples that contained enough germanium to be measured by this method The lower limit at which germanium can be determined quantitatively by spectrographic analysis is 50 parts per million (p. p. m.), but concentrations of less than 20 p. p. m. can be detected qualitatively.

Jan 1, 1959

By Jeffrey A. Aldinger

This U.S. Bureau of Mines report presents an analysis of surface coal mining accidents involving mobile equipment for the years 1989 through 1991. Mobile equipment is defined as haulage trucks, front-end loaders, bulldozers, scrapers, and road graders. These five pieces of mining equipment accounted for 20 pct of all surface coal mine accidents and 41 pct of the fatalities. The general discussion of these accidents covers the accident causes, the primary activity of the accident victims, and other contributing factors. A more detailed analysis of accidents associated with each piece of mobile equipment is also provided. This report will provide mine managers and mine safety personnel with a better understanding of the hazards associated with mobile mining equipment. It identifies where improvements in mobile equipment safety can be made and those areas requiring additional safety emphasis, such as safety training, work procedure changes, or engineering changes to the equipment or work environment. The analysis was performed by a team of researchers using accident data and narratives provided by the Mine Safety and Health Administration.

Jan 1, 1995

By W. M. Mark

This investigation was undertaken to develop methods to improve the quality of titanium sponge produced by the Bureau of Mines modification of the Kroll magnesium reduction process. Research revealed that by systematic elimination of detrimental impurities introduced with the raw materials and by improved handling and processing techniques, high-quality ductile titanium with a hardness of less than 110 B.h.n. (Brinell hardness number) can be produced consistently. This improvement was accomplished by helium (or argon) stripping of residual atmospheric and other dissolved gases from the titanic chloride, preliminary dehydration of crude titanium sponge, and careful regulation of the titanium tetrachloride (TiC14) feed rate to the reactors.

Jan 1, 1960

By Walter D. Holland

This study was undertaken to determine miners' breathing zone concentrations of diesel exhaust components, to investigate any relationships between these concentrations and vehicle type, the presence of emission controls, vehicle usage, and ventilation conditions, and to make recommendations for monitoring and ventilation requirements. Twenty-four mines including two con l mines were surveyed. Sampling was done for CON, NON, SOx, PNA, aldehydes, and particulates. hi most mines, concentrations of at least one contaminant exceeded one half the standard or TLV. The concentrations of gases arc probably sufficiently reduced by a minimum air velocity of 50 fpm. A sufficient reduction of particulate concentrations may require as high as 400 fpm air velocity. Vehicle age, type, or usage appear to have little or no effect on contaminant concentrations. PNA levels were below detection limits in all but a very few samples. Minimum requirements for routine monitoring should include formaldehyde, COx, NO2. It is further recommended that better definition of the minimum ventilation requirement be obtained.

Jan 1, 1978

By K. L. Paciorek

The primary objective of this program was to determine the toxic fume and fire hazard of elastomeric noise abatement materials with a limited effort expended on the evaluation of specific treatments applied to mine timbers. Under the conditions employed, for a dimethyl silicone rubber, formaldehyde presented the major toxic threat; acrolein was the main toxic species for both polyester and polyether urethanes and an acrylonitrile-butadiene-styrene resin; in the case of flame-retardant styrene-butadiene rubber compositions, hydrogen chloride, and in the case of PFA-treated timber, furfural, were the major toxic compounds. Of the materials studied, the flame-retardant styrene-butadiene rubbers presented the greatest toxic hazard. The generated data have been reduced to toxic load tabulations amenable to employment for potential hazard assessment.

Jan 1, 1982

By Elizabeth A. Johnson

The vaporization thermodynamics of the aluminum-silicon carbides Al4SiC4 and Al8SiC7 were studied by the Bureau of Mines over the temperature range of approximately 1,500 to 1,700 K. Vapor pressures were measured by a Knudsen effusion-mass spectrometry technique in which powdered samples were effused from graphite crucibles through small orifices. For each compound, a total of six orifice diameters was tested to verify equilibrium within the cell. Aluminum, mass number 27, was the only vapor species detected over the range 4 to 200 amu. Experimental results are based on the following equations for incongruent decomposition: A14SiC4(cr) - 4A1(g) + SiC(a,hex) + 3C(gr); Al8SiC7(cr) - 8A1(g) + SiC(a,hex) + 6C(gr). The observed vapor pressure-temperature relationships determined with a cell orifice area of 2.0 x 10-3 cm2 for Al4SiC4 and 1.81 x 10-3 cm2 for A18SiC7 are the following: Log P - (-18,682/T) + 12.476, for Al4SiC4 (1,550 to 1,643 K) and Log P = (-19,308/T) + 12.421, for Al8SiC7 (1,526 to 1,784 K), with P in pascals and T in kelvins. Third-law analysis of the data provided the following heats of formation: A14SiC4 ?H at 298.15 K - -50.0 kcal/mol and A18SiC7 ?H at 298.15 K - -92.1 kcal/mol.

Jan 1, 2011