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By Robin B. McCulloch

No producing mines are in the study area. Sample results indicate the only resources in the study area are low grade phosphate deposits associated with Cuyama Phosphate Mine (fig. 1). Within the study area, are more than 21.4 million tons of inferred subeconomic phosphate rock resources which would be reserves at an 80 percent higher phosphoric acid price; weighted average grade is 4.84 percent phosphorous pentoxide (P205). About 17.6 million tons of similar grade are outside the area to the northwest. The South Cuyama Oil Field, adjacent to the study area (fig. 1), produces petroleum from the Vaqueros Formation which underlies parts of the study area. Oil and gas potential was evaluated by U.S. Geological Survey. INTRODUCTION Location, Size, and Geographic Setting The U.S. Bureau of Mines conducted a mineral survey of the Fox Mountain RARE II area (No. 5120) during the summer of 1981. The area was examined to determine the presence or absence of mineral resources and reserves, and to estimate tonnage and grade where possible.

Jan 1, 1982

By R. W. Huber

While conducting an investigation on electrolytic reduction of magnesium oxide in 1943, it became necessary to obtain accurate data on the conductivity and density of various mixtures of fused chlorides. AZ the required information was not available in the technical literature, or there were inconsistencies in the data from several investigators, an independent study was made at the Bureau of. Mines laboratory at Salt Lake City on the conductivity and density of the molten chlorides MgCl2, CaCl2, BaCl2, KCl, and NaCl and the binary mixtures of MgCl2 with the other four chlorides. Studies were also made on the binary system KCl-CaCl2 and on certain portions of several ternary systems. Measurements covered a temperature range from the melting point to 1,000° C. The results of this study were reported in an intra-Bureau report prepared early in 1944. Since then the Bureau of Mines has received several requests for data on fused chlorides; the results of the previous study, therefore, are being published to make the data available.

Jan 1, 1952

By A. Wahab Khair, N. P. Reddy

"Abstract. This paper attempts to characterize coal breakage due to the action of a continuous miner. Coal blocks with an approximate dimension of 45.7 cm x 38.1 cm x 15.2 cm (18 in. x 15 in. x 6 in.) were first subjected to confining pressures equivalent to in-situ conditions. Then the blocks were cut along the face/butt cleat direction by the cutting head of a specially designed unique automated rotary coal cutting simulator (ARCCS), simulating the action of the continuous miner in underground coal mining. During the tests under a particular set of in-sit and operating parameters a number of other para¬meters such as 1) penetration of bit into coal, 2) penetration resistance (thrust and cutting pressures), 3) rotating velocity of cutting head, and 4) acoustic emission activity in the coal block were monitored. After each cutting cycle the fractured surfaces were photographed and a velocity survey was conducted by using a sonic technique. At the end of each experiment, the coal fragments were collected in bags using a vacuum cleaner. These fragments were then sieved for size distribution analysis.INTRODUCTIONThe Federal Coal Mine Health and Safety Act of 1969 was enacted to emphasize to coal operators that the airborne respirable dust should not exceed 2 mg/m3, thus reducing the incidence of coal workers pneumoconiosis.Dust control techniques such as conventional water sprays and dust collectors are only partially effective and require additional equipment expenditures. A more authentic approach would be to reduce respirable dust at the source the continuous mining machine cutting head, where the fragmentation process occurs. Improving the fragmentation process by characterizing the coal breakage will not only reduce respirable dust at the face, but it will also decrease the amount of respirable dust that is liberated during the secondary handling.Fragmentation of coal can be expressed as a function of three major groups of parameters; namely, 1) coal properties, 2) in-situ conditions and 3) operating parameters. This paper deals with the characterization of coal breakage along both face/butt cleat direction as a function of machine operating parameters such as rate of advance, angle of attack, bit configuration, bit lacing (spacing and pattern) and bit speed at various equivalent in-situ pressures."

Mar 1, 1989

By F. C. Houghten, R. R. Sayers, C. P. Yalaglou

"Introduction.Atmospheric conditions relative to high temperature and humidity are of great importance in mining, as well as in such allied fields as railroad and vehicular tunnels. An extended investigation into the effect of these factors on men has been in progress for some time, both in the field under actual working conditions, and at the Pittsburgh experiment station of the bureau in cooperation with the American Society of Heating and Ventilating Engineers and the U. S. Public Health Service.For several years one of the writers (Dr. Sayers) and L. Harrington, supervising mining engineer of the bureau, have been studying the effects of hot humid atmosphere in metal mines on the comfort and efficiency of the workers. Some of the reactions experienced in still and in moving saturated mine air at temperatures of 90 to 100°F., with men at rest are presented in a recent paper.****The present paper is based on experiments made under carefully controlled conditions to determine the relative feeling of warmth experienced by men in atmospheres of various degrees of temperature and humidity. The work was conducted by the research laboratory of the American society of Heating and Ventilating Engineers, at the Pittsburgh experiment station of the Bureau of Mines, in special physchrometric chambers built for this purpose. It was carried on under the direction of F. Paul Anderson, director of the laboratory, Dr. R. R. Sayers and A. C. Fieldner of the Bureau of Mines. The results given in this paper are for still air only. Investigations of the effects of moving air are being continued, and will be reported later."

Jan 1, 1924

By J. J. Drost

This Bureau of Mines investigation studied the effect of thermal treatments upon concentratability of a western Mesabi Range nonmagnetic taconite ore and is a sequel to Bureau of Mines RI 7567. Magnetic tube tests were used to develop the data needed to calculate separation efficiency, the primary measure of concentratability. A horizontal tube furnace was employed to heat treat and reduce the hematitic ore samples. The two variables studied were roasting temperature and cooling method. The manner of cooling, either by slow cooling or quenching in water, produced no significant difference in concentratability. Roasting temperatures employed ranged from 500° to 1,000° C, and a temperature of 650° C effected the best concentratability. The temperature of 650° C correlated with the most effective roasting temperature for grindability.

Jan 1, 1973

By D. E. Wolfson

The Bureau of Mines carbonized 35 coal samples from Logan and Mingo Counties) W. Va., at 900° C using the Bureau of Mines-American Gas Association method, and determined yields of products and physical properties of cokes. Twenty samples represented the No.5 Block, Stockton, Chilton, Cedar Grove, Lower Cedar Grove, Alma, No. 2 Gas, and Eagle beds in Logan County, and 15 samples represented the Coalburg, Buffalo Creek, Winifrede, Cedar Grove, Lower Cedar Grove, Alma, and No.2 Gas beds in Mingo County, W. Va, Chemical analyses were determined for all coals. All coals in both counties rank as high-volatile A bituminous. Most of the coals are chemically suitable for metallurgical coals. Coals with accept-able ash and sulfur contents can be used as major constituents in coking blends with higher rank coal to yield coke with satisfactory properties for blast furnace use.

Jan 1, 1967

By R. R. Trengove

This paper is one of a series published by the Bureau of Mines on mining methods and operation practices. It describes the open-pit mining method and operations of the Kaiser Steel Corp. Eagle Mountain iron-ore mine, which is in the extreme southeastern part of California 175 miles east of Los Angeles in Riverside County. Nearest town to the mine is Indio, which is 60 miles away by an excellent highway (fig. 1). Elevations at the deposit vary from 1,400 to 3,000 feet. Figure 2 is a plan map of the Eagle Mountain iron mine. Kaiser Steel Corp. built a model camp at the mine, with all modern conveniences (fig. 3). The camp, comprising 145 homes, dormitories, mess hall, commissary, post office, and recreational facilities for 600 people, is at 1,390-foot elevation. The area has winter-resort weather between October and May, with occasional drops of temperature to 25° at night. From June to September temperatures sometimes rise to 1200 during the day. Rainfall is scant, approximately 2 inches a year, the majority of which comes as cloudbursts during the summer months.

Jan 1, 1956

By B. W. Gandrud

In 1927 Coghill5 showed that there is considerable liberation of the iron oxide mineral from gangue when the Alabama red iron ores are ground to a size suitable for classification and tabling, but that there is not sufficient to make possible a high extraction and a high grade of concentrate. Coghill states: High extraction and high grade of concentrate cannot be obtained without grinding to a size comparable with flotation or cyanide practice. If grade of concentrate be sacrificed the grinding need not be so severe.

Jan 1, 1934

By R. L. Brown

This report is the 18th in a series summarizing Bureau of Mines research and technologic work on coal and related investigations. The previous 17 reports have covered fiscal years, but this report covers not only the fiscal year from July 1, 1952, to June 30, 1953, but also July through December 1953, to bring the report to a calendar-year basis. Most of the material in this report relates to publications issued during the reporting period, Some work is mentioned briefly on which publications have not yet been issued or on which data are riot expected to be published, for security or other reasons, and in a few instances publications issues before the reporting period but not included in the previous report are mentioned.3/ Further details on the published work described herein may be found by referring to the publications cited in the footnotes. During the reporting period, the Bureau directed its research and technologic work on coal toward developing end encouraging increased conservation and more efficient use of our mineral fuel resources through more efficient and safer mining methods and improved methods of preparing and utilizing these fuels. Some significant advances, particularly in coal-mine safety, mining methods, and development and utilization of low-rank coma have been made.

Jan 1, 1954

By G. S. Rice

This paper describes preliminary tests at the Bureau's Experimental Mine to determine, under conditions that may prevail in a bituminous coal-mine heading, how small a quantity of fire damp may bring coal-dust into suspension and ignite it. The results show that the explosion of as little as 150 cubic feet of an explosive mixture of gas and air containing 9 per cent natural gas may start a disastrous explosion of coal-dust. This is a very small volume, of gas, to cause such a result. Let us suppose that this amount of explosive mixture, as at the face of an entry which was 10 feet wide and the face was overcut to a depth of 6 feet and an upper layer of coal 2.5 feet thick had been removed, the recess so made would have a volume of 150 cubic feet. Furthermore, only 13 cubic feet of pure methane is needed in thin volume to produce this 9 per cent explosive mixture.

Jan 1, 1930

By John Ward Smith, Neil B. Young

Shale specific - gravity to oil - yield relationships were developed for black shales of the New Albany Formation of Kentucky from data collected on core samples representing the complete section of the formation in three counties . Linear equations for estimating oil yield from measured specific gravity and for estimating specific gravity from measured oil yield were shown to be applicable within small error limits to all the sites tested . Variation in pyrite content is the largest source of error .

Jan 1, 1964

By T. F. Dumm, O. Trass, V. R. Koka, L. G. Austin

"The size distributions of carefully screened 2 size fractions of ground materials were determined using a Microtrac laser dif-fractometer. The size distributions were fitted to the empirical function P(x) = 1/[1 + (x50/x)1] where P(x) is cumulative mass fraction less than Microtrac size, x. The standard deviation of A for a 50 second test time was approximately 0.5, so that seventeen test times give a mean with an estimated error within t 0.25 (95% confidence level). Values of were 5.44, 4.82, 4.40 for a coal ground under different conditions, indicating statistically different shape distributions; the average value for mica was 2.91 owing to the high aspect ratio of the particles. The ratio of x50 to the geometric mean sieve size was 1.2 for the coal and 0.70 for mica.1 IntroductionKoka and Trass have presented evidence [1,2] that materials ground in the Szego mill [3] give different shapes depending on the milling conditions. The variations in shape were deduced qualitatively by viewing SEM photomicrographs of selected 1/2 screen fractions. This paper quantifies their observed differences in shape by using measurements of the size distributions of screen fractions examined in a laser diffractometer [4] (Microtrac, Model 7991). The basic concept is that particles of 'a given ""screen"" size will give a wider distribution of ""Microtrac"" size when the particles are flaky with high aspect ratios, and a narrower distribution when the particles approach the cubical and spherical geometries.2 TheoryAustin and Shah [5] have shown that coal screened within a 1. 1/2 upper-to-lower sieve size range will give rise to a much wider distribution of Microtrac size. They found that the screen interval of irregular fragments of comminuted coals or quartz gave Microtrac size distributions which could be described by the simple function"

Jan 1, 1988

By Will H. Coghill, C. O. Anderson

In July 1921 , we were assigned by the U. S. Bureau of Mines to an investigation of milling methods in the Tri - State zinc district ( Missouri -Kaneas- Oklahoma district ) . The work has progressed without interruption , and about onehalf of the funds allotted for it has been expended . This preliminary statement abcut the nature of the work and the results so far obtained , has been prepared for the information of the operators , and through their assistance to insure the greatest possible progress during the remainder of the work . A general survey of the district was made , and many of the mining companies cordially offered the facilities of their plants for the investigation . The work was finally centralized at the plant of the 0. M. Bilharz Mining Co. Its manager , F. H. Gartung, and his successor , O. W. Bilharz , have been especially helpful , also the millmen at this plant and elsewhere have rendered assistance without which the work could not have advanced . The Missouri School of Mines and Metallurgy , Rolla, Mo. , and the Miami School of Mines , Miami , Okla . , have given hearty cooperation . The Webb City Iron Works and the Joplin Supply Co. donated some necessary apparatus .

Jan 1, 1922

By Robert P. Vinson, Kissell. Fred N., Edward D. Thimons

"The Bureau of Mines investigated the presence and extent of methane accumulations in mine roof cavities using a full-scale mine model. Methane was released at a constant rate into the roof of a cavity built onto a 700-ft wind tunnel. Two box-shaped roof cavities were used in the study: one had a volume of 114.7 cu ft; and the other had a volume of 57.3 cu ft. Methane concentration was measured at 28 sampling points in the cavities using 21 different combinations of gas emission rates and air velocities. Brattice hung in the cavity helped reduce methane concentrations without auxiliary ventilation. It was also found that the effective ventilation rate increased by a factor of 40 in the large cavity and by a factor of 20 in the small cavity when air velocity was increased from 100 to 600 fpm.INTRODUCTIONAny location in a coal mine where 5 pct or more of methane is present constitutes a potential site for an explosion and roof cavities are likely locations. Unfortunately, little is known about the buildup of methane in roof cavities. Some research has been done using scale models where no air flows past the cavity so that methane disperses only by diffusion (5) 4 a rare situation in mines.No known cavity-model investigations have been made that simulate air and methane flow conditions normally encountered underground. These Bureau of Mines studies were undertaken to determine the extent and manner of methane buildups in coal mine roof cavities with air velocities in the range normally found in coal mines and with various methane emission rates."

Jan 1, 1978

By W. L. Dare

This information circular is one of a series, published by the Federal Bureau of Mines, on methods and costs of mining uranium ore on the Colorado Plateau. This report describes the relatively small-scale operations of the Salt Wash miner: The mining method followed, the equipment used, and the production costs. It describes 10 lease-operated mines of Union Carbide: Nuclear Co. that are typical of Salt Wash operations on the plateau. These mines lie within the Uravan mineral belt3/ and arc in the Gateway, Bull Canyon, and Uravan mining districts. (See fig. 1.) Generally the ore bodies occur as irregular, discontinuous layers of ore minerals within sandstone beds in the Salt Wash member of the Jurassic Morrison formation. The ore bodies sometimes occur as rolls, pod associat with carbonaceous trash, or tabular masses. Their size and erratic distribution preclude the use of a prearranged and uniform stoping system. The mining method is simply to follow the ore and leave open scopes behind.

Jan 1, 1959

In the interest of safety ii: coal mining, the Bureau of Mines recommends: That all active underground coal mines, whether working or idle, have one or more fans in continuous operation. The capacity and installation shall be such that the entire mine workings are adequately ventilated at all times. Main fairs shall be located on the surface in fireproof housing offset from the line of any mine opening. The housing shall be provided with ample pressure-relief doors or other devices easily opened by the force of an explosion. The installation shall permit prompt reversal of air flow. For mines that liberate gas, the fan shall have at least two independent sources of rower immediately applicable. Ventilation of underground workings in coal mines is needed whether or not explosive gas is present. Natural ventilation is unreliable and often uncontrollable. Main fans should be on the surface; if they are in the mine, fire or explosion may make access difficult or dangerous and render the installation inoperative.

Jan 1, 1939

By K. C. Dean

During the investigation of the occurrence of manganese deposits in western United States, the Bureau of Mines collected 2-ton samples from three oxide manganese ores in the Columbia and Elberta Mining Districts, Tooelo and Juab Counties, Utah. To determine the amenability of these ores to standard ore-dressing methods: of concentration, extensive laboratory tests were made. The Wildcat property, one of those sampled, is 7 miles east of Fairfield, Tooele County, Utah. The ore is described as a replacement deposit and occurs along fracture and bedding planes of shale and limestone. Experimental work was done on a sample taken from a stockpile at the mouth of the shaft. The Wildcat manganese ore is intermediate in grade (25.7 percent manganese) and contains clay as the principal gangue constituent. A high-grade product was obtained with high recovery of Manganese by simple washing.

Jan 1, 1949

By W. W. Odell

"It has long been recognized that coke is a more desirable fuel than bituminous coal in water-gas apparatus of present design, but still considerable headway has been made in the use of the latter fuel as a substiaute for coke. This is particularly true in the Central States where the supply of high-grade coke has been very limited and uncertain during the past few years, and where coking coals of low sulphur content were available in quan¬tities. In fact, with, the present difference in price of coal and coke, it is possible to realize a marked saving when using a coking bituminous coal as generator fuel.Difficulties have been encountered in the use of such fuel, but they have, to a large extent, been overcome. One of the chief obstacles in the use of the more general utilization of bituminous coal for water-gas manufacture, is the fact that, with normal operation, the capacity per unit of time is reduced. This of course is a serious problem for plants operat¬ing at capacity with coke fuel. However, this difficulty can, to a large extent, be remedied by a changed method of operating, and can be entirely remedied by a combination of the latter with a change in the design (or proportions) of a water-gas set. The preceding statement, the reader will understand, refers more particularly to a carburetted water-gas set.In the manufacture of water gas from coke, present practice requires that for continuous 24-hour service the heat of combustion of all the carbon monoxide (CO) generated during the air blow be utilized in addition to the sensible heat of the gas coming from the generator. This is doubly true when making carburetted water gas from bituminous coking coal. The reasons why this is so are apparent when the following factors are considered."

Nov 1, 1920

By Geo. H. Williamson

This paper describing the dredging operation of J. K. Davison & Bro. on the Allegheny River near Pittsburgh, Pa., is one of a series being prepared for and published by the United States Bureau of Mines on methods and costs of dredging sand and gravel in the United States. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total costs. It is recognized that publication of total costs might in many instances cause embarrassment to individual operators as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of H. R. Hissrich, chief engineer of the Goodman Engine and Machine Co., in compiling details of the dredge construction; of H. H. Stewart, auditor of J. K. Davison & Bro., in preparing cost and performance tables; and of J. R. Thoenen, mining engineer of the United States Bureau of Mines.

Jan 1, 1932

By C. M. Mason

Bureau of Mines studies were made on the sensitivity of several ammonium nitrate-fuel oil (AN-FO) mixtures to bullet impact. The experimental work was done with one military rifle and two high-velocity sporting rifles with a variety of ammunition. For the three rifles used, the order of efficiency in initiating detonation in AN-FO mixtures was 220 Swift >300 Weatherby Magnum >30-&apos;06. The velocity of the bullet was found to be a decisive factor in the initiation. The sensitivity of various materials studied increased as follows: Clay-coated prills with 4 percent oil <fresh surfactant-coated prills with 4 or 6 percent oil <surfactant-coated prills with 4 or 6 percent oil and aged 270 days <crushed prills with 6 percent oil <very low-density, surfactant-coated prills (micronized), with 4 percent oil.

Jan 1, 1963