Search Documents

By Gary A. Kingston

Chromium resources in the United States are estimated at 1.8 million tons of recoverable chromium contained in 22.5 million tons of chromite-bearing material. Additional resource is presumed existent in large, but as yet undetermined, quantities of material containing less than 10 percent Cr203. No domestic resources are being mined presently (1969). Excluding transportation charges to domestic consuming areas, the total 1.8 million tons of chromim is estimated to be available, in ore or concentrate, at costs up to $0.64 per pound; 63 percent of the total is available under $0.11 per pound; and 38 percent under $0.08 per pound. It is judged that transportation from the resource areas to the existing market centers would add nearly $0.05 to the cost of a pound of chromium contained in ore or concentrate. Technically effective beneficiation methods have been developed for much of the known domestic resource, and further development might reduce costs of processing these materials. However, at present, domestic chromium resources are noncompetitive with foreign sources.

Jan 1, 1970

This report discusses the nonfuel critical minerals position of the United States-both current and future (to the year 2000). We have assumed that there will be no major global disturbances-military, political, or economic-during the rest of this century. However, international relationships, strategies, and conditions that affect the supply of minerals are very tenuous, normal trading patterns can be easily upset, and national and ideological objectives can and do interfere with "normal" free market conditions. For example, the Department of Defense has reported that the Soviet Union is engaged in a strategy designed to reduce the availability of strategic minerals, through either physical disruption, market manipulation, or domination of producing or neighboring states. Although such a strategy poses serious concerns for the United States and the free world, the impacts of disruptions are not covered in this publication. Historical Perspective The modern industrial economy of the United States is founded on the production and use of minerals.* Two hundred years ago our forebears began taming a raw continent, developing a base for agriculture and a rudimentary minerals producing system. In the 19th century, with the aid of imported labor and capital, the development of America's vast natural resources was undertaken, and the transition from an agricultural to industrial society was underway. By the century's close, the United States had emerged as a great industrial power, partly through the development of such mineral resources as iron in Minnesota and coal in Pennsylvania.

Jan 1, 1983

By B. I. Ferber

Sodium chloride aerosol was employed to determine respirator filter penetration in a manner suitable for use in Bureau of Mines approval and certification procedures. The aerosol was produced by an ultrasonic generator and treated to yield the proper conditions of relative humidity, particle size, and concentration. Respirator filters were exposed to the aerosol; filter penetration (down to 0.02 percent) was determined with a flame photometer. Results are comparable with those obtained in another laboratory using different equipment.

Jan 1, 1970

By T. E. Gray

This report describes the preparation characteristics of the significant coalbeds in Harrison County, W. Va. It is one in a series of Federal Bureau of Mines reports planned to determine coals suitable for the production of metallurgical coke, either as mined or after beneficiation. Over 6.5 million tons of coal was produced in Harrison County, W. Va., in 1958, of which over 3.7 million tons was cleaned mechanically in seven preparation plants. All of the coal cleaned was from the Pittsburgh bed. It has been estimated that more than 1,816 million tons of coal remains in the county in beds 12 inches or more thick. The Pittsburgh and Redstone beds were selected by the Bureau for a study based on current production rates and estimated minable reserves. Sample locations were selected following a study of the literature, conferences with mining engineers and mining company officials in the field, and examination of the available sites. Six samples were collected from the Pittsburgh bed, and three samples came from the Redstone bed, Float-and-sink tests of the samples collected from the Pittsburgh and Redstone beds showed that neither coal could be upgraded to a metallurgical fuel under the standards set up for this study, even after intensive preparation. Finer crushing of the samples moderately increased the yields and slightly reduced both the ash and the sulfur contents in the 1.30-specific-gravity float fractions. Finer crushing slightly decreased the yields in the 1.58-specific-gravity float fractions, whereas it reduced the sulfur content 0.11 percent for the Redstone sample and 0.46 for the Pittsburgh sample.

Jan 1, 1961

By A. B. Cecala

The Bureau of Mines has developed a pallet loading dust control system designed to lower the dust exposure of workers during the bag stacking process at mineral processing facilities. The system makes bag stacking much easier because the pallet height remains constant throughout the entire bag stacking cycle through the use of a hydraulic lift table. The system uses a push-pull ventilation technique to capture the dust generated during bag stacking. A low-volume, high-velocity blower system operating at approximately 150 cfm blows a stream of air over the top layer of bags on the pallet. The blower system is composed of two 3-in air jets (approximately 1,200-ftjmin velocity) directed toward an exhaust system on the opposite side of the pallet. As these air jets travel across the pallet, they entrain the dust generated during bag stacking. The exhaust ventilation system pulls approximately 2,500 cfm of air and dust through the exhaust hood. This exhaust air can then be dumped into a baghouse ventilation system, or filtered before being discharged outside the mill. During a laboratory evaluation, a 70-pct dust reduction was recorded for the bag stacker. The system was then evaluated in an actual working environment. The first field evaluation was performed at a silica sand operation in which one worker performed the entire loading and bag stacking process. This worker's dust exposure was lowered 76 pet when using the new pallet loading system. The second field evaluation showed only moderate dust reduction, but this was mainly attributed to an overriding problem associated with background dust and the cleanliness of the bags. From both the ergonomic and production standpoint, the system was well received by both the workforce and plant management.

Jan 1, 1988

By R. D. Leitch

"INTRODUCTION This report is another of the series on the effect of drouth and low water on the pollution of streams by coalmine drainage. A previous report3 dealt with work on Bennett Branch of Sinnanahoning Creek, Pa. This report deals with the results obtained during a similar study of Black Lick Creek, Two Lick Creek, and Yellow Creek. All of these belong to the same drainage system. Two Lick Creek is a tributary to Black Lick Creek, and in turn Yellow Creek is a tributary to Two Lick Creek, as shown in Figure 1.Black Lick Creek was of such a volume that a seasonal investigation was not entirely feasible. Yellow Creek was found to have mines only near the mouth, except a few of status unknown to the writer at the extreme head-waters, and the stream was also more or less inaccessible for regular and frequent sampling. Two Lick Creek was found to be most suitable of the three.ACKNOWLEDGMENTThe work reported has been carried on under the direction and with the advice of Dr. R. R. Sayers, chief, health and safety branch, and W. P. Yant, supervising engineer, Pittsburgh Experiment Station."

Jul 1, 1931

By 1928-05-01

"The carnotite ores of Colorado and Utah were the chief source of radium for many years. In the fall of 1922; news of the very rich deposits of radium ore discovered in the Belgian Congo caused almost complete cessation of domestic production. The Congo ore contains pitchblend and a number of alteration products, including the new minerals bequerelite, curite, kasolite, stasite, and dewindite. Reports indicate that a considerable amount of ore containing over 50 per cent U308 has been produced. It seemed certain that radium could be extracted from the Congo ore at a much lower cost than from the relatively low-grade carnotite; and in order to preserve their elaborate marketing organizations, the larger American producers made agreements with the Belgium syndicate to market the foreign product in this country. The price of radium has been held at $70 per milligram. Extraction of radium from carnotite by the usual methods does not appear to be profitable at that price. With one exception, all American firms ceased production after their accumulated stocks of ore had been treated. The United States Radium Co., which continued to treat carnotite for several years, has recently shut down its plant.Although there is probably a large profit derivable from the treatment of Congo ore, it is not likely that the Belgium Syndicate will meet sufficient competition to cause any reduction in the present quotations. It is not known how long the high-grade ore will last, but when exhausted the price of radium may be expected to advance. According to K. L. Kithil3 it is the opinion of interested parties that, so far as can be forseen, radium will in future years never again be obtained at the present low price.Carnotite contains the valuable element, vanadium, which is not present in the Congo ore. The recovery of-vanadium is an important factor in the cost of extracting radium from carnotite, and under favorable conditions carnotite can be profitably treated for the vanadium alone. Vanadifecous sandstones are found ranging all the way from roscoelite (vanadium mica), containing little or no uranium; to a high-uranium and low-vanadium carnotite. Ores containing 2 per cent or more U308 are classed as radium ore and are sold on the basis of the uranium content, which is proportional to the radium content. Only in exceptional cases have ores been evaluated on the basis of both the radium and vanadium contents, although the presence of vanadium has undoubtedly influenced the price of radium ore."

May 1, 1928

By L. Kaufman

Fifteen boride composites were synthesized by hot pressing and evaluated by physical and incendivity testing as non-sparking tool materials. The incendivity tests, conducted at the U. S. Bureau of Mines, Albany Research Center, compared the boride compo-sites with standard cobalt-bonded tungsten carbide material used for coal cutter bits. Two titanium diboride composites and two zirconium diboride composites out-performed cobalt-bonded tungsten carbide in wear resistance and reduced tendency to cause ignitions. However, three of these candidates exhibited undesirable chipping. The remaining candidate, a TiB2-(Ni, Cu) composite, did not chip, nor did it cause ignitions at levels where cobalt-bonded tungsten carbide tools caused ignitions in the incendivity tests. Thus, this material appears to be a logical candidate for further development.

Jan 1, 1973

By E. G. Davis

Large-scale ultrafine grinding tests of a coarse kaolin were made using the Bureau of Mines developed attrition grinding process in continuous open-and closed-circuit systems. A 20-inch diameter attrition grinder, designed and constructed at the Tuscaloosa Laboratory, was used. Studies included single- and multiple-stage open-circuit grinding, and also continuous grinding tests in closed-circuit with a 6-inch-diameter solid bowl centrifuge. Clay feed, containing 9.0 percent minus-2-micrometer esd, was used at fates up to 840 pounds per hour. Multistage grinding tests gave better results than single-stage treatment when equivalent clay feed rates were used. Closed-circuit grinding tests yielded ground products containing slightly more minus-2-micrometer-esd clay than the open-circuit grinding when using the same clay feed. Energy consumption was lower in closed-circuit grinding than in batch or open-circuit grinding. A modified two-stage closed-circuit grinding system gave the best grade of product and amount of minus -2-micrometer-esd clay produced per pound of clay feed. The ground product from this test contained 88.5 percent minus-2-micrometer-esd material and electrical energy consumption was 327 kilowatt-hours per ton of minus-2-micrometer-esd material produced.

Jan 1, 1973

By J. R. Thoenen

[Since the publication of the preliminary report on this subject in July, 1927, (The Wire Saw in Slate Quarrying, Preliminary Report, Serial No. 2820, by Oliver Bowles) the wire saw has been in constant daily operation at the quarry of the Colonial Slate Company. Luring this time between twenty end thirty successful cuts have been made varying in length from forty-five to ninety-two feet and in depth from six to ten feet. No accurate time records have been kept on these cuts but they have totaled over 12,000 sq. ft. of area and required 19,000 lineal fact During these cuts the average speed of cutting has risen from the 12.8 sq. ft. per hour obtained in the original recorded tests to between 15 and 20 sq. ft. per hour, with the present rate running very close to 20 sq. ft. per hour at this quarry.]

Jan 1, 1928

By John B. Gayle

The probable inadequacy of physical tests of coke for the purposes for which they are made has been a subject for discussion for many years. However, little has been published in this connection, even though most workers in the field believe that the physical properties of coke are of major importance in its utilization in the steel and allied industries. In fact, the reproducibility of the recognized tests is largely unknown or can only be approximated. This situation occasions many difficulties when attempts are made to judge the coke-production qualities of various coals or coal blends. During World War II the Coke Production Committee, composed of representatives from industry and the Solid Fuels Administration, concluded that study of existing testing methods and possible improvements would be of material assistance in answering questions relating to coke quality. Since that time the Bureau of Mines has taken samples of coke produced in industrial slot-type coke ovens in connection with studies aimed at extending coking-coal reserves by adding to the list of sources known to be suitable for this purpose. Testing procedures on these cokes were arranged so that the data obtained would yield information on (1) the degree of precision of tests commonly used in the industry, (2) the causes of the known poor reproducibility in several of the physical tests, and (3) possible improvements or modifications of existing physical testing procedures.

Jan 1, 1953

By M. G. Zabetakis

At ordinary temperatures and pressures methyl ethyl ketone (MEK)-air mixtures containing between 2.0 and 11 vol.-pct. MEK and methyl isobutyl ketone (MIBK)-air mixtures containing between 1.5 and 7.5 vol.-pct. MIBK are flammable. However, MEK-bromochloromethane (BCM)-air mixtures containing at least 6.2 vol.-pct. BCM and MIBK-BCM-air mixtures containing at least 7.0 vol.-pct. BCM are nonflammable. Also, MEK-BCM-air and MIBK-BCM-air mixtures containing less than 18.7 vol.-pct. oxygen are nonflammable. To assure the formation of nonflammable mixtures when mixed with air, MEK-BCM vapor mixtures must contain at least 1.6 vol. BCM per volume MEK, and MIBK-BCM vapor mixtures must contain at least 2.8 vol. BCM per volume of MIBK; these quantities of BCM would be produced by liquid mixtures containing 55 vol.-pct. BCM in the first case and 60 vol.-pct. in the second. An MIBK-BCM-trimethylene chlorobromide mixture containing equal volumes of each liquid forms nonflammable mixtures with air at ordinary temperatures and pressures. The same is true of a liquid mixture containing 34.6 pct. (liquid volume) BCM, 34.b pct. perchloroethylene, 15.4 pct. MIBK, 7.7 pct. toluene, 3.85 pct. ethyl amyl ketone, and 3.85 pct. trimethylene bromide.

Jan 1, 1960

To reduce the possibility of injury to operators and damage to equipment caused by collision of mining vehicles during coal loading. Approach An energy-absorbing bumper was developed and tested underground on a continuous miner. How It Works The bumper, a long box-like weldment backed by five energy absorbers, is attached to a continuous mining machine by a hinge behind the cab. See Figure 1. When a shuttle car collides with the bumper, or when it is otherwise struck, the energy absorbers are compressed. This absorbs and dissipates part of the kinetic energy of the colliding vehicle, thereby reducing or eliminating its destructive effects. Each energy absorber consists of two chambers separated by a freely-moving piston. One chamber (Figure 2) contains hydraulic fluid. The second chamber contains a gas. When a collision causes the absorber to compress, the hydraulic fluid in the first chamber is forced past a metering pin and through an orifice. The hydraulic fluid then pushes against the piston, compressing the gas in the second chamber.

Jan 1, 1978

By Jerry J. Gray

The utilization of secondary titanium was determined in a study by the Bureau of Mines, and a 10-year statistical table showing supply and distribution patterns is presented in this report. Over the total 10-year period, estimated scrap consumption is larger than estimated scrap supply. Trends from the estimated data indicate that titanium is in short supply and probably will continue to be in the future. Because of higher processing costs for recycle scrap, scrap will tend to migrate to the steel and aluminum industries and to ferrotitanium production and exports. Nonrecoverable losses of titanium metal during processing was determined to be a potential area for research.

Jan 1, 1971

By M. J. Ferrante

The Bureau of Mines recovered rhenium powder from scrap tungsten alloy containing approximately 25 percent rhenium. Oxidation of the scrap at 950° C separated volatile rhenium heptoxide from tungsten trioxide. Minor amounts of tungsten, iron, and nickel were removed by selective precipitation from a rhenium solution from which was recovered crystalline ammonium perrhenate. Experimentation showed that hydrogen reduction of minus 325-mesh ammonium perrhenate at 1,000° C produced rhenium powder averaging 2.1 microns in size (Fisher Sub-Sieve method). The powder contained <50 ppm of total metallic impurities and 1,070 ppm of total interstitial impurities. Sintered compacts had a density of 95 percent of theoretical. Approximately 96 percent of the rhenium contained in the scrap alloy was recovered.

Jan 1, 1969

By M. J. Sapko

The U.S. Bureau of Mines has developed a portable meter for measuring the component concentrations in binary dust mixtures whose constituents have different optical reflectivities. The meter has been successfully tested with coal dust-rock dust mixtures taken from coal mines in Europe and the United States and fluorinated-carbon mixtures that change from carbon black to pure white during fluorination. Additional study has also substantiated the theoretical expressions used in the design of the meter.

Jan 1, 2010

By J. H. Perry, D. W. Houseknecth, C. A. Kertis, A. T. Iannacchione

Major problems facing the development of coal and gas resources of the Hartshorne Coalbeds include the complex distribution of minable and unminable coal, high methane content and bed pressure, faulting, variations in degree of dip, presence of natural gas fields in associated sandstones, and legal problems, caused by local geologic characteris- tics, in identifying gas origin. This Bureau of Mines study provides pertinent geologic information for long-range planning of subsurface coal and gas production from the Hartshorne Coalbeds. Pittsburg, Coal, Hughes, and Atoka Counties, OK, have approximately 1 billion metric tons (1.1 billion short tons) of Hartshorne coal in place. The methane resource of Hartshorne Coalbeds is estimated at 9.2 billion m3 (325 billion ft3) and varies with overburden and rank, These estimates were compiled from gas well density logs, coal-core data, out- crop measurements, abandoned mine maps, and the literature. The Hartshorne Coalbeds represent a valuable coal and gas resource which at present is contributing nothing to coal and gas production. This report discusses potential problems and serves as a reference for future exploration and development work. Recognition of these potential geologically related problems prior to development of this basin will reduce hazards and allow for an economic recovery of these resources.

Jan 1, 1983

By D. J. Parker

In attempting to discuss a subject of this character it should be clearly understood at the outset that the purpose is not to emphasize the mere fact of occurrence of such catastrophes, the memory of which time has largely relegated to oblivion, but rather to stress the means of their prevention, available not only subsequent to but also at the time of occurrence. A careful, conscientious, unbiased study of the causes of mine explosions leads inevitably and definitely to the conclusion that the human element is the most important factor. The human factor should however, be evaluated in terms of responsibility--responsibility on the part of the employer to recognize the existing hazards and take the necessary remedial action, and on the part of the employee to perform his duties faithfully, diligently, scrupulously, and in strict conformity with State mining laws and company rules or other regulations.

Jan 1, 1933

By Martin H. Stanczyk

The direct dissolution of a typical zinc sulfide flotation concentrate by elevated temperature and pressure leaching was investigated. The concentrate assayed about 55 percent Zn, 32 percent S, 6 percent Fe, and 1 percent Pb and contained minor quantities of copper and precious metals. The influence of various factors on the dissolution of the zinc in acidic and ammoniacal pulps when using oxygen as the oxidant was determined. The tests revealed that the sphalerite was difficult to oxidize. Complete dissolution of the mineral required vigorous and intimate nixing of the gaseous, liquid, and sold phases. The addition of pyrite or sulfuric acid to water slurries of the concentrate was required to obtain a high zinc extraction when leaching under acidic conditions. The quantity of pyrite and acid used was about 0.125 and 0.25 pound, respectively, per pound of zinc sulfide contained in the leach charge. In tests with acid, about 96 percent of the zinc was extracted from the concentrate in 1 hour at 200° C. when the oxygen partial pressure was 75 pounds per square inch gage or higher. Leaching with a continuous flow of air as the oxidant gave results that were almost as good as those obtained when oxygen was used, In tests with air fed through the autoclave at 320 liters per hour, 95 percent of the zinc was dissolved in 1 hour, Acid leach solutions assaying approximately 58 grams Zn per liter and containing Fe, Ni, Cr, and Cu impurities were produced in the better tests. The leached residue consisted essentially of red iron oxide together with substantially all of the lead and precious metals.

Jan 1, 1961

By John M. Dale

Sulfur is a plentiful, low cost, unique material whose physical properties can be altered and employed in structural applications. This program was undertaken to develop an optimum sulfur based formulation for use as a coating to both seal and support mine walls. The initial effort in the program was devoted to a laboratory study of the physical and mechanical properties of a variety of sulfur base coatings that were specifically formulated for this application. Concurrent with formulation development, laboratory equipment and techniques were developed for spray applying the sulfur based coatings to the ceiling and walls of a structure that simulated the interior of a mine. Much of the formulation work was guided by the experiences encountered when attempting to spray the formulations overhead. One hundred parts of sulfur modified with 10 parts of talc, 3 parts of milled glass fiber, and 2 parts of dicyclopentadiene was found to be a fire retarded, low odor, low eye irritation, sprayable formulation for sealing and strengthening mini, walls. An invention disclosure on this formulation was submitted to the Bureau of Mines and a patent application was filed. Various mineral samples were obtained and adhesive strengths of the formulation to these samples in both the wet and dry state were measured. With the development of an attractive sulfur based coating material, attention was directed to the design, fabrication, and testing of a portable spray application unit so that coatings might be applied in the field to various rock surfaces and earth formations for further evaluation. The unit was fabricated in the Southwest Research Institute shop. Once operational, the unit&apos;s capabilities were field tested and demonstrated at three separate locations. Upon completion of the field testing, the unit was shipped to the Spokane Mining Research Center where Bureau personnel were instructed in the use of the unit.

Jan 1, 1972