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By Foster Fraas

Electrostatic separation depends on a number of electrical and mechanical properties such as conductance, contact potential, dielectric constant, and particle shape. In routine testing it is desirable that the application of each of those properties be investigated. The conductance property is best utilized in a separator having an ionic field, whereas the contact potential requires a separator with a pure static field. Dielectric constant and particle shape also influence the response in these two fields. There is no separator on the market that can be adjusted for all these requirements. The separator described in this paper is satisfactory for this purpose and is provided with a dielectric electrode, which permits formation of high-intensity static fields.

Jan 1, 1951

By J. C. Franklin

The Bureau of Mines substantially reduced shale degradation in a coal mine by two spray coat applications of a water-base epoxy sealant. More than 12,700 square feet of passageways were treated, and in 18 months only one failure occurred. This failure was due to improper spray application, Material costs averaged 13 cents per square foot, and labor costs were 7 cents per square foot. Labor included moving all materials into the mine, the setup time for each of the areas coated, and application of coatings.

Jan 1, 1977

By A. P. Grossman

'This report was prepared by Shell Oil Company, Mining Ventures Department in accordance with Cooperative Agreement No. 14-09-0070-b53 dated September 10, 1976, between the United States of America, Department of the Interior, Bureau of Mines and C(b) Shale Oil I Project, Ashland Oil Inc., Shell Oil Company, Operator. After completion of this report the Shell Oil Company withdrew from participation In the C(b) Shale Oil Project and advised the Bureau of Minus that plans for publication of this report had also been withdrawn. The Bureau of Mines acting under terms of the Cooperative Agreement hereby releases this report for general information.

Jan 1, 1976

By Bernard Porter

The rate of the heterogeneous reaction between reactor-grade yttrium and lithium fluoride in lithium fluoride-yttrium fluoride mixtures was measured using a quartz spring balance. At 950° C the magnitude of the rate of reaction is 10-5 grams of yttrium/cm2-sec. The heat of activation for the reaction is 38.3 kilocalories per mole of LiF. A surface-controlled mechanism is proposed in which LiF is adsorbed on the yttrium metal surface. An activated complex is formed when additional LiF reacts with the adsorbed LiF-metal site. The activated complex then decomposes to the products) which are lithium metal and YF3. The importance of the reaction in the electrowinning of yttrium metal from fluoride electrolytes is discussed.

Jan 1, 1967

By L. B. Pankratz

Present-day interest in the rare-earth elements and their compounds, for both metallurgical and ceramic uses, makes it highly desirable to accumulate basic thermodynamic data that can be applied to theoretical considerations of the processing of these substances. Such data still are seriously lacking. This Bureau of Mines paper reports the results of high-temperature heat content measurements of the sesquioxides of four rare-earth elements--europium, gadolinium, neodymium, and samarium--and of the closely related element, yttrium. The temperature ranges covered by the measurements are as follows: Monoclinic Eu2O3, 298°-1,802° K. Cubic Eu203, 298°-1,350° K. Monoclinic Gd203, 298-1,802° K. Cubic Gd203, 298°-1,550° K. Hexagonal Nd203, 298°-1,795° K. Monoclinic Sm203 298°-1,798° K. Cubic Sm203, 298°-1,149° K. Cubic Y203, 298°-1,799° K.

Jan 1, 1962

By Lee M. Manna

Approximately 10,000, 10-Ton, 4 wheel, 2 truck, coal mine cars are in general service in U. S. Mines. None are equipped with an automatic braking system. Very few are equipped with hand or parking brakes. The report lists major manufacturers of the car and develops estimate as the percentage represented. It complies physical specification of cars of major car manufacturers, and develops a composite clearance diagram. It then discusses a pneumatic system employing truck components for an automatic system that could be used as an add-on unit. The components are listed and priced and a schematic circuit is developed for the system. Recommendations as to future programming are made.

Jan 1, 1976

By S. L. May

Investigations by the Federal Bureau of Mines indicate that hafnium and zirconium compounds of acceptable purity can be extracted from Nigerian zircon concentrates. Chlorination and caustic soda fusion techniques were used to extract 85 to 95 percent of the valuable metals from the concentrate. The extracted hafnium and zirconium compounds were purified by recrystallization of the oxychlorides or by formation of complex salts during chlorination. The zirconium-hafnium product of the recrystallization method contained 15 parts per million of uranium, and the product of the salt-complex method contained less than 10 parts per million of uranium. The hafnium was separated from zirconium by solvent extraction methods. A zirconium product containing 0.3 percent hafnium and a hafnium product containing 4 percent zirconium were obtained. At the request of the Atomic Energy Commission (AEC), work was started to develop techniques for processing Nigerian zircon concentrates in commercial installations presently engaged in producing zirconium and hafnium metals from ores. The Nigerian zircon has a high hafnium content, but the presence of uranium and thorium is a problem not normally encountered in processing zircon concentrates.

Jan 1, 1961

By Peter F. Steidl

As part of the Bureau of Mines methane control program, the Upper Free-port coalbed was studied in Fayette County, Pa., where this coalbed lies about 650 feet below the Pittsburgh coalbed and contains the largest remaining reserves of any coalbed in the county. Coal and overburden isopachs, structure and joint pattern maps, and a fence diagram were prepared using data from gas and oil exploration logs and coal outcrops. These maps will aid in deter-mining the need and/or feasibility of degasifying the Upper Freeport coalbed in the study area. Much of the coalbed in this area is under 600 to 1,400 feet of overburden. By correlation with data from the Pittsburgh coalbed, the gas content at depths of this order is estimated to be between 140 to 300 cf/ ton of coal, for a total of 190 to 400 billion cubic feet of methane in this coalbed in Fayette County.

Jan 1, 1977

By R. H. Sprute

Underground accumulations of slimes in the Henderson mine are routed to two large collection pits where they are dewatered and consolidated by application of direct current. Densified material is then removed to ore cars by rubber-tired front-end loaders and transported out of the mine. This Bureau of Mines report describes the electrical dewatering installation and compares its efficiency of operation with that predicted from preliminary laboratory studies performed by the Bureau. Direct current from a 150-kw rectifier (applied for 44 hours at 400 amperes and 65 to 70 volts) converted slimes containing 25.3 percent solids to material ranging from 44 to 65 percent solids. Better results can be expected if the ramp and front sections of the pits are treated separately, using higher current density.

Jan 1, 1980

By Harry W. Campbell

A mineral survey by Bureau of Mines personnel identified no mineral resources or mineral occurrences with development potential at prospects in the Mecca Hills Wilderness Study Area (WSA). Bentonite occurrences are in Skeleton Canyon and Surprise Canyon. Sand and gravel occurrences are numerous in and near the WSA. Much of the Mecca Hills WSA was leased for oil and gas exploration in 1983. No current mining claims or other leases were found in the study area. The Skeleton Canyon Clay Mine yielded clay to seal irrigation canals, Clay to seal ponds was also mined from the Red Top Clay Mine west of the USA. A sand and gravel pit south of the study area (near Box Canyon Wash) supplied material for local construction projects. A commercial sand and gravel pit was operating in 1983 near the mouth of Thermal Canyon 4 miles west of the WSA.

Jan 1, 1984

By R. Larry Grayson

Barrett EA, Kowalski KM [1995]. Effective hazard recognition training using a latent-image, three-dimensional slide simulation exercise. Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9527. NTIS stock number: PB95-170379. Beus MJ, Orr TJ [1995]. Computer modeling and analysis of the Greens Creek Mine, Admiralty Island, AK. Spokane, WA: U.S. Department of the Interior, Bureau of Mines, RI9530. NTIS stock number: PB95-176418. [ ]

By Lewis V. Wade

Barrett EA, Kowalski KM [1995]. Effective hazard recognition training using a latent-image, three-dimensional slide simulation exercise. Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9527. NTIS stock number: PB95-170379. Beus MJ, Orr TJ [1995]. Computer modeling and analysis of the Greens Creek mine, Admiralty Island, AK. Spokane, WA: U.S. Department of the Interior, Bureau of Mines, RI 9530.NTIS stock number: PB95-176418. [ ]

By A. W. Khair, L. D. Gehl

"This paper describes the mechanism of coal and rock cutting from quasi-static indentation through dynamic indentation to rotary cutting. The results indicate that during quas~static indentation, a crushed zone, and subsurface fractures develop. The crushed zone is a potential source of dust generation. Dynamic indentation produces a crushed zone due to the frictional resistance offered by the coal or rock during penetration of the bit. Confining pressure changes the mode of failure from tension to mixed tension and shear. The wider bit causes larger crushed zone and more dust generation. The rotary cutting is a combination of quasi-static and dynamic indentation which results in chip formation. 1. INTRODUCTIONThe trend from conventional mining to continuous machine-cutting of coal, using more productive machinery is inexorable. Intolerable levels of dust generated at the face is an indication of inefficient coal or rock cutting by these machines. The Federal Government of the United States paid about 11.7 billion dollars workman compensation to more than 470,000 miners with Coal Workers Pneumoconiosis (Newmeyer, 1981). Bieniawski and Zipf (1985) reported that annual benefit payments were about 2 billion dollars. The need for research m improving coal cutting 1s therefore paramount. The enactment of Health and Safety Act in 1969 in the United States triggered the initial investigation into coal cutting mechanism and cutting tool design. The European countries were also engaged in the same area of research, however, their emphasis was in the use of wedge shaped bits. In 1981, the United States Bureau of Mines commissioned the South West Research Institute to investigate the effect of operating parameters mainly on airborne respirable dust in order to provide a healthier and safer atmosphere for coal mine workers.A research program by the Department of Mining Engineering, West Virginia University, USA was initiated to study the fragmentation mechanism during coal/ rock cutting. The research program was divided into three areas of research, namely quasi-static indentation, dynamic indentation and rotary cutting."

Dec 1, 1995

By J. W. Paul

The tests described herein were made in the course of a series of experiments on coal-mine ventilation factors which the Bureau of Mines has beep; conducting for the past two years at its experimental mine near Bruceton, Pa. The object of the present tests was to determine the leakage of two air locks which had been placed in the experimental mine as hart of the equipment for tests on friction factors. Position of the Doors. The first or inner lock gas across the aircourse between No. 1 and No. 2 left butt entries, and forced the air through these butts. An air-measuring suction in No. 1 butt determined tae volume passing at tent point.

Jan 1, 1924

By M. H. Kline, Wing G. Agnew

"INTRODUCTION The Yancey-Crawford tract, located 1-1/2 nines east of Yancey station on the Norfolk & Western Railway in Rockingham County, Va. was from 1917 to 1941 considered an unusually promising manganese prospect. Because of the favorable geologic formations and because of the common occurrence of manganese in the district and Virginia's large production of these minerals from this area, geological report 3/ have listed this tract as the No. 1 prospect in the State. During World War I, extensive geologic studies were made to locate manganese deposits similar to those exploited at the Crimera mine near Waynesboro to alleviate this mineral shortage during the existing emergency.In September 1941 the Bureau of Mines started exploratory drilling on the tract in an effort to discover and block out reserves of manganese minerals as authorized by the 76th Congress under the Strategic Materials Act. After five drill holes wore sunk, the project was terminated October 1941."

Apr 1, 1948

By L. C. IlsLey

"There are two general classes of accidents that prevail in and about mines, namely - (1) those that through the nature of mining work can only be lessened, and (2) those that by proper precaution can be eliminated altogether. Explosive accidents that ordinarily take place while explosives are being transported in and about mines belong to the second class, that is, by proper care all such accidents can in general be avoided.The following table gives a brief summary of several accidents and disasters that have occurred in the United States and indicates the need of universal preventive measures as a basic part of all State regulations.ACCIDENTS AND DISASTERS OCCURRING WHILE TRANSPORTING EXPLOSIVES.***"

Sep 1, 1923

By R. P. Vinson

The Bureau of Mines evaluated two real-time light-scattering dust monitors by measuring their response to Pittsburgh Seam coal dust and Arizona road dust (ARD). Both monitors, the model PDS-l, a personal dust sensor, and the model PCD-l, a digital dust indicator, are made in Japan by Sibata Scientific Ltd. Tests were conducted inside a laboratory aerosol chamber designed to maintain a uniform spatial distribution of the test dust. PDS-l and PCD-l measurements of concentrations for each test dust were averaged over 4-h test periods and compared with simultaneous gravimetric measurements. Both dust monitors responded linearly with mass concentration with both coal dust and ARD. However, the linear response of the PDS-l differed from that of the PCD-l for both dusts.

Jan 1, 1987

By Gordon L. Kinney

The only economically important mineral currently produced in Bangladesh was natural gas. Bangladesh was not a world? ranked producer of any mineral commodity, but the possibility of producing and exporting commercial amounts of liquefied natural gas (LNG) was being examined. Proved reserves of natural gas were sufficient to supply most of the country's industrial and domestic heating and electric needs and still support an export-oriented LNG plant. Other mineral production was of virtually no significance to the economy, although there were a few prospects for nonmetallic mineral development. Bangladesh continued to make economic progress during 1978 and into early 1979. Gross domestic product (GDP) at current prices rose from $6.6 billion in 1976-772 to $8.2 billion in 1977?78 and $9.3 billion in 1978.79.2 In fiscal 1979, the economic conditions were favorable until a severe drought hit most of the country. It W88 reported that conditions were the worst in 40 years, and 88 of July 1979, substantial crop losses were predicted. The agricultural sector accounts for over 53% of the GDP and about 75% of all employment. The poor weather will cause economic problems in the form of slower growth, larger trade deficits, and a higher rate of inflation. The 1978.79 statistics showed that real GDP increased just 4%.

Jan 1, 1981

By F. B. Tough

"INTRODUCTION Organizations formed for the purpose of conducting conservation work in oil fields, in order to conserve and prolong the supply of crude petroleum are rare and novel. Such an organization is the Rocky Mountain Petroleum Association, Denver, Colo, As our production of petroleum can no longer keep with the consumption, the plan of organization, character of work, and results obtained by this association are well worth considering. It is hoped that the results achieved in the Wyoming fields will serve to stimulate similar organizations among operators in the state or other oil fields of the United States, The Rocky Mountain Petroleum Association, Danvers Colo., was formed in May, 1919. It comprises the Midwest Refining Co,. The Ohio Oil Co., and the Continental Oil Co. These three companies entered into a cooperative agree¬ment with the Federal Bureau of Mines whereby $30,000 would be spent under the direction of the bureau, which agreed to furnish competent men, and to furnish the work and expenditure of funds. Although the financial burden for the first year's work, now drawing o a close, was carried by only three companies, they stipulated their desire that the benefit of the work should accrue to the industry, and that the personnel employed should be as zealous to assist one operator as another, without regard to whether ha was contributing to the support of the work or not."

Apr 1, 1920

Vanadium, molybdenum, and a titanium-10 percent vanadium alloy were evaluated for their susceptibility to stress corrosion cracking in a number of corrodents. Tests were conducted utilizing conventional U-bend techniques with subsequent evaluation in a pneumatic constant-load apparatus. Vanadium and molybdenum were generally resistant to stress corrosion cracking in the media studied. U-bend specimens of vanadium showed evidence of stress corrosion cracking in 6 li hydrochloric and 18 li sulfuric acids; however, tensile stress specimens exposed to these solutions did not exhibit stress cracking. Similar results were obtained when U-bend specimens of molybdenum were immersed in 10 percent formic acid. Titanium-10 percent vanadium alloy was susceptible to stress corrosion cracking in 10-percent (2.85 li) hydrochloric acid solution. Heat treating the alloy greatly reduced its corrosion rate and its susceptibility to stress cor-rosion cracking in this medium.

Jan 1, 1965