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By R. L. Crosby

Microscopical and X-ray diffraction techniques were used to identify two intermediate phases in that part of the solid region of the magnesium-cerium system between and Mg3Ce. Previous literature had reported only one intermediate phase for this region, 1)12t chemical analysis determined the approximate composition of the two compounds to be Mg23Ce2 and Mg17Ce2. The range in composition of the two intermediate phases was found to be limited to less than 0.3 atomic percent cerium. The study did not determine the crystal structure of Mg17Ce2, but that of Mg23Ce2 is tetragonal with a = 10.33 A and c = 19.51 A.

Jan 1, 1966

By M. L. Wouden

In the late 1970's, the Bureau of Mines began to examine the criteria for reestablishing vegetative cover on coal strip mine spoils near Glenrock, WY. A 9-acre plot, consisting of (1) spoils covered with topsoil, (2) spoils without topsoil, and (3) spoils treated with sewage sludge, was constructed. These plots were seeded with Tegmar intermediate wheatgrass (Agropyron intermedium), Fairway crested wheatgrass (A. cristatum), and Critana thickspike wheatgrass (A. dasystachyum). After 5 yr, the topsoil had about 70 pct plant coverage. Revegetated spoils, without topsoil addition, averaged approximately 30 pct plant coverage, and sewage sludge-treated spoils had about 45 pct plant coverage. Comparison of grass types showed the intermediate wheatgrass produced greater surface coverage.

Jan 1, 1986

By J. W. Higgs

This paper, describing the operation of the Gifford Hill & Co. plant at Hoot Spur near Texarkana, is one of a series being prepared for and published by the United States Bureau of Mines on methods and costs of mining and preparing gravel and sand throughout the United States. These tapers are designed to disseminate technical information regarding the methods used. The cost tabulations represent local operating expenditures only and not total production costs. Although the publication of total costs might not be advisable in some instances yet a knowledge of operating costs is essential to the technical discussion and study of methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulation shall ensue. The plant described combines some features of dredging and some of dry-pit operation, as material is excavated in a dry pit with a drag line, hauled to the plant in standard-gage cars, and then pumped. This operation should be of special interest to operators whose deposits contain a large quantity of clay.

Jan 1, 1936

By Vern L. Kegler

This paper is one off a series dealing with mining methods and costs, sponsored and published by the United States bureau of Mines. ACKNOWLEDGMENTS The author acknowledges the, constructive and helpful suggestions and criticism of W. F. Lamoreaux, vice-president, and general manager of the Ducktown Chemical & Iron Co. United States Geological Survey Professional Paper- 139, by W. H. Emmons and F. B. Laney, has been drawn upon for some of the information contained in the paragraphs or history and geology.

Jan 1, 1931

By W. R. Hardwick

This paper describing the mining methods of the Inspiration Consolidated Copper Co. is one of a series being prepared by the Bureau of Mines on mining methods and costs in various mining districts of the United States. The story of mining at Inspiration is of particular interest because, after 127,812,000 tons of low-grade copper ore were successfully mined, the mining method was changed from block caving to open-pit. As the open pit became deeper, many features of the former block-caving operation that were exposed elucidated concepts of the mechanics of caving that previously had been assumed but not observed. The conversion to open-pit mining was accomplished by unique combinations of equipment and the introduction of ingenious engineering and operating practices that have extended the expected life of the mine for many years.

Jan 1, 1963

By W. R. Hardwick

This paper describing the mining methods of the Inspiration Consolidated Copper Co. is one of a series being prepared by the Bureau of Mines on mining methods and costs in various mining districts of the United States. The story of mining at Inspiration is of particular interest because, after 127,812,000 tons of low-grade copper ore were successfully mined, the mining method was changed from block caving to open-pit. As the open pit became deeper, many features of the former block-caving operation that were exposed elucidated concepts of the mechanics of caving that previously had been assumed but not observed. The conversion to open-pit mining was accomplished by unique combinations of equipment and the introduction of ingenious engineering and operating practices that have extended the expected life of the mine for many years.

Jan 1, 1963

By W. W. Adams

"The fifth annual National Safety Competition conducted by the United States Bureau of Mines to determine the best safety records at mines and quarries during the calendar year 1929 has been concluded, and the general results of the contest are presented herewith. To the winner in each of the five groups into which the contestants were divided there has been awarded the bronze trophy 'Sentinels of. Safety,' donated by the Explosives Engineer magazine. The trophy for bituminous coal mines was won by a mine in Alabama; that for metal mines by an iron-ore mine in Michigan; that for nonmetallic mineral mines by a salt mine in New York; that for quarries and open-cut mines went to a limestone quarry in Michigan;. the trophy provided for anthracite mines was, of course, won by a mine in Pennsylvania, as all of the anthracite mines participating in the contest are situated in that State.Winners of the trophies were selected by a committee of sward in accordance with rules governing the contest and on the basis of accident records furnished by the various companies to the Bureau of Mines. These records were summarized by the bureau and the results submitted to the committee. Members of the committee are W. H. Cameron, managing director of the National Safety Council. William Green, president of the American Federation of Labor; James F. Callbreath, secretary of the American Mining Congress; T. T. Read, Vinton professor of mining of Columbia University and editor of 'Mining and Metallurgy'; C. B. Huntress, executive secretary of the National Coal Association; A. J., Curtis, assistant to the general manager of the Portland Cement Association; A. T. Goldbeck, director of the engineering bureau of the National Crushed Stone Association.Thirty-four States were represented in the l29 contest. Among the plants which participated were 68 bituminous coal mines, 29 anthracite mines, 54 metal mines, 19 nonmetallic mineral mines, all of the foregoing being underground mines, and 141 quarries or open-cut mines. A total of 106,533,006 man-hours of work was reported by all of the companies. Accidents during the year numbered 7,008 and represented a period of disability equal to 986,306 man-days. Hence the accident-severity rate for all plants combined represented 9.3 man-days of disability for each thousand man-hours of exposure to hazard. Similarly, the combined accident-frequency rate for all plants showed that 66.3 accidents occurred for every million man-hours of exposure to hazard. Both of these rates indicated an improvement over the combined rates for all plants in the previous year's contest. The reduction in the accident-severity rate centered chiefly in the metal mine group, though all except the quarry and open-cut mine group shared in the reduction; the improvement in the accident-frequency rate was in all croups except anthracite and metal, the rate for the former having increased while that of the latter remained unchanged."

May 1, 1930

By Alexander L. Peyton

The Magruder and Chambers copper deposits in the Little River gold district, on the border line of Lincoln and Wilkes Counties, Georgia, have been known for a number of years (fig. 1). The Magruder deposit was first opened as a gold mine but has produced mostly copper and load. Records show that about 50 cars of concentrates were shipped from this property. No record of any production at the Chambers deposit is available. The Bureau of Mines, in its program of investigation of strategic minerals deposits, diamond drilled 10 holes, totaling 3,784 feet, on the two properties between December 3, 1948, and June 23, 1949. Eighty-eight core samples were analyzed, and the analyses and drill-hole data are presented in this report.

Jan 1, 1950

By James Westfield

A brief résumé follows of activities of the Division of Coal-Mine Inspection that have had a favorable effect on health, safety, and the reduction of injuries at coal mines: 1. The Federal Mine Safety Code fur Bituminous Coal and Lignite Mines of the United States was issued originally by the Director of the Bureau of Mines on July 24, 1946, after consulting with management and labor representatives of the coal-mining industry. The code has been used by Federal coal-mine inspectors while inspecting bituminous-coal and lignite mines as a basis for determining the existence of unhealthful and unsafe conditions and practices in these mines. A revised code was issued by the Secretary of the Interior on October 8, 1953, after further consultations with representatives of management and mine workers and was incorporated by reference in the 1952 and subsequent bituminous -coal wage agreements. The agreement of May 29, 1946, between the Secretary of the Interior, acting as Coal Mines Administrator under authority of Executive Order 9728, and the United Mine Workers of America, covering bituminous-coal and lignite mines in Government possession, charged Federal coal-mine inspectors with the responsibility of making periodic investigations of the mines and reportin; to the Coal Mines Administrator any violations of the Federal Minis Safety Code. Federal coal-mine inspectors also had temporary authority to close mines found to be imminently dangerous, but such authority under Executive Order 9728 was removed on June 30, 1947, when Government control of the mines was terminated.

Jan 1, 1960

By Ann G. Kim

Fires that occur in abandoned coal mines, waste banks, and in coal outcrops constitute a serious health, safety, and environmental hazard. Toxic fumes, the deterioration of air quality, and subsidence constitute the greatest hazards from these fires. Although tires on abandoned mined land (AML) occur in every coal-producing state, the severity of the problem varies. Methods to extinguish or control AML fires, including excavation, fire barriers, and sealing, are generally expensive and have a relatively low probability of success This U.S. Bureau of Mines report includes information from a variety of sources, i.e., agencies of the Federal Government, State agencies, research reports, conference proceedings, product information, and technical literature. This information has been collated into a comprehensive discussion of AML fire problems. Data on past fire control projects and on the estimated extent of the current problem have been compiled. Factors affecting the occurrence, propagation, and extinguishment of AML fires are discussed. Conventional fire control methods are described, and their probable effectiveness is evaluated. Information on the hazards of AML fires and safety considerations is included. The status of current technology, recent improvements in fire control methods, and areas of current research are discussed.

Jan 1, 1993

By A. C. Johnson

This paper is one of a series being prepared by the Bureau of Mines on exploration, development, mining methods and costs at various mines in the United States. It describes such methods at the Lincoln tungsten mine of the Wah Chang Mining Corp., Lincoln County, Nev. The purpose of these reports is to promote development and conservation of our mineral resources by disseminating technologic information on mining methods, practices and costs. The Lincoln mine in Lincoln County, Nev., in the southeastern part of the [tate], was acquired by the Wah Chang Mining Corp., in April 1951. Mining methods and costs are of special interest at this property because of the low costs and good production record achieved through a well planned program of exploration, development, and exploitation. Operations were discontinued in July 1957 after the Federal Government suspended the tungsten purchase program.

Jan 1, 1959

By Paul M. Tyler

This paper is one of a series of digests of foreign mining legislation and court decisions prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of Yugoslavia was prepared from information furnished by John Dyneley Prince, American Minis- ter at Belgrade, in response to a questionnaire submitted by the Bureau of Kinos and transmitted through the courtesy of the Department of State.

Oct 1, 1929

By J. Wade Watkins

One potential peaceful application of nuclear explosives is stimulating the production of liquid or gaseous hydrocarbons from essentially nonproductive deposits of petroleum, natural gas, oil shale, and tar sands. Within the United States the appreciable difference between producible proved reserves and ultimate reserves and resources of hydrocarbon deposits is of such magnitude that much petroleum, natural gas, shale oil, and bitumen will not be produced unless significant technological progress is made in production techniques. The shattering effect of contained nuclear explosives and, to a lesser extent, the heat produced, have been considered as stimulative forces when the thickness, depth, and nature of such deposits permit considering the use of nuclear devices. Mechanical production problems would be less in an oil or gas reservoir than in an oil-shale or tar-sands deposit. Also, tar-sands resources in the United States may not be adequate to warrant serious consideration of applying nuclear-explosives stimulation. Gas reservoirs should present the least- radioactive-contamination problem. The technical feasibility of using nuclear explosives cannot be evaluated fully at present. Additional information is needed on the effects of pressure, heat, and radioactivity on the solids and fluids of hydrocarbon deposits, the nature and extent of induced fractures in different rock media, and the possibility of isolating and confining or removing radioactive contaminants. Final technical feasibility can only be determined by a field test. If technical feasibility is established, economic feasibility will depend upon the comparative cost of producing hydrocarbons by nuclear explosives and by conventional means. It is probable that an economic comparison would favor nuclear stimulation only where devices of relatively high yield could be used practicably and safely.

Jan 1, 1964

By Henry P. Wheeler

Natural gas was first stored underground in Welland, County, Ontario Province, Canada, in 1915.3/ The following year natural gas in the United States was first stored underground successfully in the Zoar field near Buffalo, N, Y. Only three additional storage fields were in use in the United States in 1930, but by 1940 the number had increased to over 30, and since that time growth has been more rapid. At least 80 fields, with a combined storage capacity of 440,828 MM c. f ., were being utilized by 1949.4 / In May 1952, 142 storage projects having a capacity of 915,000 MM c.f. were in operation .5/ These fields are distributed from New York to California--from Michigan to Texas. In the Appalachian region alone, there are 101 storage fields with a combined capacity exceeding 526,000 MM cu. ft. Why Natural Gas is Stored Natural gas is stored in order to be readily available to meet the needs of consumers.

Jan 1, 1952

By Joseph J. Wallace

1. The investigation shows that nine coal beds have been mined in Harlan County, of which the Harlan and Upper Elkhorn No, 3 are the most important from the standpoint of present production. Of less importance are the Hindman, Flag, Haddix, Wax, Fire Clay, Armburgy, and Upper Elkhorn No. 2. The Harlan, Upper Elkhorn No. 3, and Upper Elkhorn No. 2 beds contain the largest remaining known reserves. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 tons per acre-foot of coal in place, are estimated at 2,138 million short tons as of January I, 1932. Of this total, 1,956 million short tons is in beds 28 inches and more thick. Areas in each bed were omitted from the estimate because available data relative to the bed characteristics are too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study, Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1954

By W. J. Fene, R. D. Currie

The value of protective clothing in the prevention of injuries has long been recognized in many of the leading industries , but the adoption of the idea into mine safety programs is comparatively new . Once started , however , the idea has grown rapidly and the results already obtained by mining companies have shown that it is fundamentally sound . Both coal and metal mining companies are rapidly adopting these protective measures , and since 1924 many mines have become well equipped with eye , head , and foot protection . At the present time approximately 70 percent of the employees in the anthracite mines of Pennsylvania are provided with safety hats . At many metal mines all employees are provided with safety hats, shoes , and goggles . The Pennsylvania mining law provides that all shaft · workers in anthracite mines shall wear protective hats . In According to a study³ made of the nature of 3,485 temporary injuries and of the parts of the body of underground coal mine employees most exposed to occupational hazards , the head and face were injured 665 times , the hands 856 times , and the feet 565 times . Of 2,555 temporary injuries in metal mines , the head and face received 484 , the hands 788 , and the feet 357 . a similar study4 made by a coal -mining company for the year 1928 , of 556 injuries the scalp received 9 , the skull. 4 , the eyes 47 , the hands 62 , the thumbs 21 , the fingers 141 , the ankle , the feet 51 , and the toes 35 . Probably most of these injuries could have been prevented by suitable protective clothing and equipment . This study also revealed that at least one injury occurred

Jun 1, 1933

By F. F. Aplan

Separation of the slightly soluble minerals (Ksp? 10-10), one from the other is one of the more difficult tasks confronting flotation engineers. This study has focused on means of separating such prominent members of this class as scheelite, fluorite and calcite from one another. Some experimental work has also been done on the minerals magnesite, dolomite and apatite. Carboxylic acid-type collectors are commonly used industrially to float all of these minerals. Thus, the problem at hand is to ascertain means of achieving selectivity between minerals known to respond rather similarly in flotation. Four techniques have been proposed for the separation of minerals of this class from each other: 1. Control of potential determining ions 2. Use of stereo-specific collectors 3. Use of flotation rate differences 4. Use of selective activating and depressing compounds. This study was directed toward a cursory evaluation of each of these techniques, and each was found to be a possible method of achieving selectivity. Stereo-specific collectors -- those whose parking area may closely match the available adsorption site on one mineral but not on another -- are a possible means of achieving selectivity between scheelite, fluorite and calcite. Stereo-hindered carboxylic acid salts and sulfonates all show selectivity between the three minerals tested. Separations also appear to be possible by the controlled use of the lattice ions (e.g., Ca and [W0=4] for scheelite, CaW04), H+, [OH-, C0-3 and HCO=3]; all of them ostensibly potential determining in the systems studied. Flotation rate differences of the minerals as a function of pH under conditions of starvation collector usage also showed promise. Scheelite and fluorite float most rapidly with sodium oleate in slightly acidic (pH 4-7) solutions whereas calcite floats most rapidly near pH 10. Use of Mn++, Pb++, or other heavy metal hydroxy complexes as activators was seen to effect each of the slightly soluble minerals differently. This is in sharp contrast to the oxygen containing, relatively insoluble minerals, where all minerals respond in a similar manner to such activation procedures. Results indicate that all four methods outlined above may potentially be used to achieve flotation separation of the slightly soluble minerals. More extensive research should be undertaken to detail the spcific applicability of each of the procedures and to make a more complete evaluation of the effect of collector type and concentration, mineral type, pH and size effects.

Jan 1, 1983

By G. W. Grove

The wearing of self-contained oxygen breathing apparatus, although relatively safe if proper precautions are taken, is dangerous if defective apparatus -is worn, if men with inadequate training, experience, and physical requirements are used, or if improper procedure is followed. This is proved by the fact that at least 26 men are known to have lost their lives while wearing-oxygen breathing apparatus since its introduction in this country about 35 years ago. Self-contained oxygen breathing apparatus, commonly called "mine rescue apparatus" and sometimes improperly referred to as "oxygen helmets," is the only equipment that can be used for respiratory protection against poisonous mine gases, regardless of concentration or against an atmosphere containing little or no oxygen.3/ Apparatus of this type was introduced in this country in 1907, and since that time it has been widely used in conducting rescue and recovery work after mine fires and explosions and in some other work. All oxygen breathing apparatus used in this country before 1918 was imported from Europe, and although this equipment provided safer, more rapid means of conducting recovery work after mine disasters, there were many mechanical deficiencies in the apparatus which resulted in the death of some of the wearers. This led to the research and experimental work by the Bureau of Mines that resulted in the development and manufacture of more reliable and efficient types of apparatus in this country.

Jan 1, 1944

By A. W. Fahrenwald

"The rate of progress in the last three years in the development of differential flotation has been rapid beyond the realization of most people. Differential flotation is no longer a ""delicate"" and unreliable process, but is now in wide use. Its ""safety"" is due to the wide use of chemicals which either depress or enhance floatability by definite modification of surfaces.The extent of the development and reliability of differential flotation methods any be emphasized by pointing out that there are now several customall-flotation"" plants in this country treating complex lead-zinc-iron ores from widely separated mines. While these ores differ in chemical composition and apparently in physical nature, the various ores treated in such a plant are passed through the same crushing and grinding equipment and through the same flotation machines and flow sheet with only slight changes, if any, in quantity and kind of chemicals and oils added.Some of the development in differential flotation is due to intelligent research on the part of well-trained chemists and metallurgists; much of It must be attributed to empirical testing.Much of the success in differential flotation is due to more care being given to constant conditions with regard to such factors as (1) fineness of grinding, (2) density of pulp entering flotation machines, (3) quantity and constancy of oils and chemicals added to the pulp, and (4) place of addition of reagents, and time of ""conditioning"" treatment of pulp with reagents."

Aug 1, 1925

To improve a miner's chances for survival in an emergency by providing an improved self-rescuer device that functions in a toxic or oxygen-deficient atmosphere. The Approach: Development of a compact, lightweight apparatus which produces oxygen by using the wearer's breath in a chemical reaction. How It Works: The device is designed to cause the user's breath, which contains water vapor and carbon dioxide, to react with potassium superoxide (K02) to produce oxygen in quantities sufficient to sustain the wearer for one hour. The system is a closed circuit and does not depend on "screening" of noxious gases. To use the device, the miner opens the top and

Jan 1, 1974