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By D. J. Singleton

Erosion corrosion of 12 alloys in phosphoric acid waste water was studied by the Bureau of Mines. Tests were conducted on oblate spheroids or cylindrical specimens in 12-and 60-cm-diam ball mills by grinding phosphate rock in gypsum pond water with a starting pH of 1.6. For comparison, tests were conducted while grinding phosphate rock in plain water. Static corrosion tests in gypsum pond water also were conducted. For all alloys, the wear by erosion-corrosion (milling with gypsum pond water) was greater than the sum of erosion (milling with water) plus static corrosion. Erosion-corrosion wear was about 1,500 to 3,000 mpy for the alloyed white cast irons, 1,000 to 1,400 mpy for commercial steel ball material and type 316 stainless steel, and 600 to 900 mpy for nickel-base alloys and a high-manganese, nitrided stainless steel. Alloy costs per unit of phosphate rock 'processed favor a low-alloy, high-carbon steel or a high-manganese, nitrided stainless steel.

Jan 1, 1985

By F. W. Horton

This paper covers the salient features of the occurrence and mining of sheet mica in the United States and the preparation of mica for market; presents the results of a study of the physical properties of domestic and foreign micas, which the author hopes may he of interest to every mica user, as it definitely answers many questions as to the suitability of various minas for particular purposes; and discusses mica-trade conditions and the future outlook for the domestic mica industry. ACKNOWLEDGMENTS The author takes pleasure in acknowledging his indebtedness to J. R. Thoenen, of the United Stator Bureau of Mines, under whose guidance the work reported herein was performed, and to Frank L. Hess, also of the Bureau, for information on the geological and mineralogical characteristics of mica-bearing pegmatites.

Jan 1, 1935

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 Ralph H. Whaite

To assist the anthracite industry obtain technical data on pneumatic packing, the Federal Bureau of Mines imported a pneumatic packing machine from Germany and installed it in a mine of a cooperating company in the Northern anthracite field of Pennsylvania. This report covers the second in a series of experiments in applying pneumatic packing for controlling strata movement (subsidence) above mine workings in the Pennsylvania anthracite region. The first experiment2/ was begun in January 1950, in a section of the mine where about 50 percent of the original coal remained in the form of pillars; since the company did not plan to mine the pillars in this particular area, pneumatic packing of the chamber voids was done for test purposes only. During this initial test the machine was operated on 204 shifts, and 652,400 cubic feet of breaker refuse material (22,834 tons) was packed into the voids of 16 chambers. The work was completed in December 1951.

Jan 1, 1956

By M. K. Quinn, N. P. Reddy, A. W. Khair

"An analysis of coal fragmentation due to the action of a continuous miner is presented. Underground coal cutting by a drum-type continuous miner was simulated in the laboratory using a specially designed unique automated rotary coal cutting simulator (ARCCS). The rotary coal cutter provided the versatility of varying the operating and in-situ parameters to provide information on the effects of generating 37 pm (0.0015 in) particles. In these tests, coal blocks with an approximate dimension of 50.8 x 35.6x 20.32 cm (20x 15x 8 in) were first subjected to confining pressures equivalent to in-situ conditions. The blocks were then cut by the rotary cutting head of the ARCCS, thus simulating the action of the continuous miner in underground coal mining. During the tests under a particular set of in-situ and operating parameters a number of other parameters 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. During the test, all the cut products were collected for size distribution analysis. After each cutting cycle the fractured surfaces were photographed and a velocity survey was conducted using a sonic technique. At the end of each experiment the cutting paths of the bits in coal were photographed using a camera attached to an optical microscope.The results led to a better understanding of the mechanisms of the fragmentation process during coal cutting and the effect of operating parameters, in-situ conditions and coal type on the size distribution of the cut product:"

Jan 1, 1989

By R. B. Tippin

To study continuous operation of the heavy liquid separation (HLS) of minerals, the Bureau of Mines concentrated spodumene from a typical ore. The studies included heavy liquid concentration, removal of the heavy liquid from the mineral products, and recovery of the heavy liquid for reuse. The research program examined the influence of feed moisture, steam consumption, stripping time, and condition of steam. Operation of multiple cyclones in series resulted in spodumene concentrates assaying 92 to 95 percent spodumene and indicated mineral recoveries of 86 to 89 percent. Continuous filtration and steam stripping produced mineral products containing less than I pound of heavy liquid tetrabromoethane (TBE) per ton of material. Problems unique to this process are discussed, including heavy liquid properties and viscosity, toxicity, material handling hazards, and safety precautions.

Jan 1, 1970

By W. E. Pittman

The Bureau of Mines, as part of its Health and Safety Technology Program, is conducting research on the use of ground penetrating radar (GPR) for mine hazard detection. GPR offers a possibility of mapping immediate below-surface geologic conditions, including faulting and other anomalies, thereby exposing potential safety hazards to miners. This report summarizes a literature review of the current status of GPR research in and outside the Bureau.

Jan 1, 1984

Comparative tests of four coals used industrially for coke production have been made by three laboratories of the Federal Bureau of Mines, each using its standard equipment and procedures for evaluating coal for coking. Two of the coals were blends used in the western and eastern sections of the United States, the third was a strongly coking coal widely used for producing coke in Alabama, and the fourth was a blend typical of those used for producing foundry coke in the Birmingham district. The coals used and the cokes produced from them covered a wide range of chemical and physical properties. The tests used at all three laboratories for determining the physical properties of the cokes were made according to ASTM (American Society for Testing Materials) methods. The excellent agreement found for the physical properties of the cokes indicated that, for the coals tested, the BM-AGA (Bureau of Mines-American Gas Association) 18-inch circular retort used at Pittsburgh, Pa" the 14-inch slot-type oven used at Denver, Colo., and the 17-inch slot-type oven used at Tuscaloosa, Ala., were substantially equivalent for evaluating coals for production of coke. Thus, added value is given to data obtained previously and independently at these three Bureau laboratories. INTRODUCTION Laboratory equipment to produce coke for evaluation has not been standardized by the industry. The results obtained with anyone design of equipment have been regarded as showing only the relative values of coal to produce coke of the requisite quality. Few systematic studies have been made to correlate results obtained in different types of equipment. Results of one, in which the Bureau of Mines participated, were published recently.2/ This

Jan 1, 1961

By John B. Goodman

This report summarizes the work done by the Koppers Company, Incorporated, in cooperation with the Bureau of Mines on the commercial evaluation of the primary low-temperature tars produced from Texas lignite in the Rockdale, Tex., plant of the Aluminum Company of America in conjunction with the Texas Power and Light Company. The interest of the Bureau of Mines in this project is twofold. First, through its cooperative agreement with the Texas Power and Light Company the Bureau has assisted in the technical design and practical operation of the prototype, externally heated, entrained-state carbonizer for producing char for electric-power production and for primary low-temperature tar. Second, the first successful operation of the prototype carbonizers employing the Bureau of Mines-Parry process on lignitic coal in 1953-54 led to the production of large quantities of primary lignitic tar, concerning which too little was known or had heretofore been published in this country.

Jan 1, 1959

By R. Vernon Helm

Four tables listing values for the various physical properties of those sulfur compounds most likely to occur in petroleum and petroleum products are given herein. The data necessary to bring the first compilation2/ in this subject up to date are given in table I -Revised and Additional Data, which includes boiling points, refractive indices, densities, and freezing points. Tables 11-, III, and IV are published for the first time and include refractive indices for the F, C, and G' lines of hydrogen and the helium D:3 line; surface tensions and viscosities, and refractivity intercepts, specific dispersions, specific refractions, and parachors. The need for information concerning the sulfur compounds in petroleum is becoming-more urgent because of the necessity of refining larger quantities of high-sulfur crude oil to meet the rising demand for petroleum products. For a number of years the Bureau of Mines has been engaged in research to make available more information concerning the properties of the sulfur compounds in petroleum. The petroleum industry has recognized the value of such studies, and as a result the American Petroleum Institute has established Research Project 48A to study sulfur compounds. The investigations under this Project are to be done in Bureau of Mines laboratories as a cooperative project in connection with the work already started.

Jan 1, 1949

By Thomas C. Atchison

The purpose of this Bureau of Mines investigation was to measure the amplitude and shape of the strain pulse and the size of the crushed zone produced in a granite by different explosives and to determine how these quantities are related to the detonation properties of the explosives. The reflection theory of rock breakage has shown that the amplitude and shape of the strain pulse incident at a free surface determine the fragmentation and volume of rock broken. Determination of the properties of an explosive that control the characteristics of the strain pulse produced in the rock will help in evaluating explosives for use in blasting. The investigation showed the different explosives produced a twofold variation in the amplitude of the strain pulse but little variation in the shape of the pulse. The explosives also produced a twofold variation in the volume of the crushed zone, but differences among the explosives were more accurately determined by strain-amplitude measurements than by crushed-zone measurements. The peak amplitude of the strain pulse and the volume of the crushed zone correlated with the calculated detonation pressure of the explosive.

Jan 1, 1959

By G. W. Jones

From evidence made available during the investigation, it was concluded that the first of a series of explosions occurred at 1:15 to 1:20 p.m. September 21, 1951, in an underground vault that housed pressure regulators on the gas-distribution lines that served Brighten. This explosion damaged the pressure regulators and permitted high-pressure gas to enter the distributing mains and individual-service lines. As a part of the gas-distribution system was not provided with means for protection against such excessive pressures, gas gained access to the interiors of many residences in this area and caused a series of disastrous explosions and fires, which took place during a period of approximately 2 hours after the initial explosion in the pressure-regulator vault. Two persons were killed in the first explosion in a residence, and a third person died of a heart attack attributed to the excitement that prevailed during the explosions and fires, Twenty-three persons were listed as injured. Forty-one residences were either destroyed or damaged - 11 by explosion and the remainder by fires, which developed as a result of gas leakage into residences. Fifteen residences were listed as "completely down" or "gutted." Unofficial estimates of property damage ranged from $1,000,000 to $1,500,000. In view of observations made and information obtained during the investigation, recommendations are presented in this report relative to the natural-gas distribution system in Brighton, which may be helpful in the prevention of similar accidents in this and other communities.

Jan 1, 1952

By J. B. Zadra

After the discovery of the rare-earth mineral deposit in the Clark Mountain area near Mountain Pass, San Bernardino County, Calif., two samples wore obtained through the Mining Division of the Bureau of Mines for investigation of possible method of concentration. Three other samples were received later from different locations in the same area. The rare-earth mineral in this ore had been identified by E. T. Schonk as bastnaesite, a fluocarbonate of the rare-earth metals containing cerium, lanthanum, praseodymium, thorium, uranium, etc. Associated with the bastnaesite were barite, silica, and some calcite. The bastnaesite contained a small amount of iron as a coloration and some manganese. Twenty to fifty percent of the weight of the samples studied was bastnaesite, or ten to twenty-five percent total rare-earth oxides; about half was cerium oxide. Apparently, none of this mineral occurred in pure form. Even the highest-grade particles 'wore contaminated by fine, interlocked grains of barite, calcite, and silica; barite contamination predominated, and the barite was interlocked with varying amounts of bastnaesite. While the specific gravities of pure bastnaesite and barite (approximately 5.0 and 4.50 respectively) differ enough to allow separation by gravity, the interlocking of the minerals nullified this difference. Consequently, only a partial separation could be made by gravity concentration. The extremely fine grained texture of most of the ore prevented grinding to a size that would make concentration by flotation practicable; a partial separation of barite by this means was effected.

Jan 1, 1952

The purpose of Volume II of this study is to provide a general plan for the pilot testing of two materials which could be used to tag explosives for both pre- and postdetonation identification and of tracing techniques which would thereby aid the investigator of an unauthorized bombing or explosion in being able to determine the source and/or user of the explosives. Volume I described the planning factors by which the tagging of explosives could be implemented on a National basis. 1.2 BACKGROUND Tagging explosives at the time of manufacture with a taggant material that could survive detonation, be recovered, and provide an investigative lead has been seriously studied for several years. This concept has gained widespread support among many law enforcement groups because of the scant clues that can presently be found among bombing residue.

Jan 1, 1977

By Raymond B. Ladoo

Deposits of talc are known in many districts in Canada but at the present time active mining operations are reported only in Ontario . Here three companies are now operating, two of which, George H. Gillespie & Co. , Ltd. , and the Anglo- American Talc Co. , are at Madoc . The operations of the former company are probably the largest and best known in Canada . The writer , in his capacity as an engineer of the U. S. Bureau of Mines , was permitted by this company to make an inspection of its mine and mill in June, 1920 , and study the methods employed . This information was desired for comparison with methods employed in the United States . The following description is based on observation made during this visit , supplemented by data supplied by the company .

Sep 1, 1920

By J. W. Town

Studies were made by the Bureau of Mines to determine the influence of textural features on the beneficiation of phosphate minerals (pellets) from selected bed and composite samples representing different rock types of the Western Phosphoria Formation. The particle size of the samples was reduced by attrition grinding to minus 20-, 28-, or 48-mesh depending on ore grade and gangue matrix. Sizing of the ground material showed that the phosphate pellets would concentrate in the plus 200-, 270-, or 325-mesh size fractions sufficiently so that the phosphate content was above the 31.5 :cent P2O5 required for acidulation. The phosphate content of essentially pure phosphate pellets was shown to range from 33 to 39 percent P2O5. Microscopic identification of the particles in each size fraction showed that the phosphate was either in the pellet form and readily liberated or so intimately associated with the gangue matrix that size reduction necessary Co obtain liberation was impractical.

Jan 1, 1967

The Bureau of Mines has successfully used sulfur hexafluoride (SF6) as a tracer gas to measure mine air flows under conditions where conventional methods have failed. SF6 was employed experimentally to measure accurately recirculation of return into intake air caused by leakage through an old stoped area, to check for potential leakage from an adjacent mine, to trace 10,000 cfm of "lost" air from an intake airway, and to measure transit air time through uranium mines. It proved useful as a means of accurately measuring airflow volumes in airways of large cross section and very low flow velocity, and in determining the recirculation resulting from underground cooling plants.

Jan 1, 1974

By F. S. Crawford

This study was made to find methods of preventing back strains, among workers in brick plants, however, the information should apply to other industries that employ hand labor too process materials. The report is based on information in letters from. Bureau of Mines engineers and other safety men in the United States who visited numerous brick plants. Back strains, as wall as hernias and other muscular strains, result when certain body structures are subjected to strains greater than, they can withstand. Such breakdowns may be prevented simply by not straining these body structures. This is simple in theory but complicated in practice. It requires primary education of new workers and reeducation of older workers in the best method of lifting, preemployment physical. examinations to select employees for the jobs that require constant lifting, all possible mechanization of material-handling operations, relocation of machinery, and elevation of working surfaces to reduce to a minimum the muscular effort the workers must exert to perform operations impossible to mechanize. Accidents of any kind are a total bee for the American economy and decrease productivity; whereas mechanization raises the level of productivity and constitutes progress toward total safety. Heavy lifting should be done mechanically whenever possible, saving the men to direct the machines. This is an essential step in preventing strain accidents.

Jan 1, 1953

By W. G. Messner

Pipelines for transporting crude oil and refined products in the United States totaled 189,982 miles on January 1, 1959. This mileage was less than a 1-percent increase from the 1956 total of 188,540 miles. During the three-year period (January 1956 - January 199), 14,886 miles of new pipe and 10,649 miles of secondhand pipe was laid. Pipe taken up in the same period was 24,093 miles. The facts regarding pipeline mileage were obtained by the Bureau of Mines from pipeline companies and information provided by the Interstate Commerce Commission. Crude-oil gathering lines, as of January 1959, were 40 percent of the United States pipeline mileage and totaled 75,182 miles, an increase of 1,656 miles during the three-year period. Crude-oil trunklines totaled 70,317 miles or 37 percent of the United States pipeline mileage, a decline of 8,277 miles from the 1956 total. Some of this loss is attributed to the converting of crude lines to refined products. Refined product lines in January 1959, totaled 44,483 or 23 percent of the United States mileage, an increase of 8,063 miles during the three-year period.

Jan 1, 1959

By A. H. WHITE, PERRY BARKER

In a consideration of the various means whereby more economical and more efficient use may be made of the fuels in the United States, the possibility of obtaining for the production of illuminating gas other and cheaper fuels than the Pennsylvania coals demands attention. For the Government, as well as for private corporations and the householder, there can be no more economical and efficient way of using some coals than through the medium of illuminating gas. In the stove, gas reduces the labor cost of heat production and lessens the drudgery of the kitchen; burned in the Welsbach mantle, it is an excellent and cheap illuminant. In addition, the coke that remains after the gas has been recovered furnishes a smokeless fuel that has about the same heating value as anthracite. Hence any investigations that will indicate how local coals through proper treatment may be substituted for the higher priced and rapidly vanishing Pennsylvania gas coals will bring about lower prices for both gas and coke and will also aid to conserve for use in metallurgical processes the coking coals of Pennsylvania and of ot,her States. The annual drain on the gas-coal resources of this country and the importance of the gas and coke industries are indicated by the fact that 8,390,129 tons of coal were carbonized in retorts in the United States in 1909. The resulting salable products from by-product ovens were 15,791,220,000 cubic feet of coal gas, 6,254,644 tons of coke, and 60,126,000 gallons of tar. The total value of all by-products was about $28,508,637.

Jan 1, 1911