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By A. L. Engel

[This report presents results of investigations of problems assigned as ore-testing projects to the Ore-Dressing Section, Metallurgical Division, of the Bureau of Mines at the Mississippi Valley Experiment Station in Rolla, Mo., during the fiscal year ended June 30, 1940.]

Jan 1, 1941

By C. Flores, L. G. Twidwell, T. S. Jordan

It is well known that manguniferous silver ores containing manganese intimate) associated with silver are not amenable to conventional extraction methods. The segregation process has been applied primarily to the recovery of copper from oxidized and oxide-sulfide ores. A new alternative process, consisting of segregation roasting followed by flotation to recover the silver from refractory manganiferous silver ores, was studied using a 23-factorial experimental design. Laboratory investigations were conducted on a manganiferous silver ore analyzing 0.02% copper, 0.09% lead, 0.33% zinc, 12.55% manganese and 187 g/t silver. The investigation was designed to study the effects of the addition of salts, coke and copper (11) oxide on silver recovery. The results indicated that 79.3% of the silver can be recovered in the absence of copper oxide and 88.4% of the silver can be recovered with a copper oxide content of 1.5% at 750°C, 2% salt (NaCI). 1 % coke and 30 min of roasting. It was concluded that the addition of copper oxide improves silver recovery.

Jan 1, 1996

By S. V. Balikov

A close association of fine gold with pyrite and arsenopyrite is observed at many gold ore deposits. Gold forms and gold distribution in sulfides of different deposits were studied. A comprehensive method including optical spectrum analysis, X-ray diffraction analysis, high-temperature X-ray diffraction analysis, scanning electron microscopy and X-ray microanalysis was used for the de-tailed investigation of the defectiveness of the structure of pyrites from different deposits. It was shown that gold content in pyrites varied from 1.5 g/t to 100 g/t compared with 30 g/t to 230 g/t in arsenopyrites. The nature and arrangement of inner inclusions of foreign minerals in pyrites as well as occurrence of fractures and macro- and microdefects were examined. Iron, sulfur and arsenic contents in all pyrite samples were determined. Chemical composition of the detected inclusions was defined. Parameters of submicroscopic structure of pyrite were estimated using X-ray Fourier line shape analysis. Estimation of real structure characteristics with calculation of submicroscopic D-blocks and root-mean-square lattice deformation 2()evalues was performed. Defectiveness of the pyrite structure can be defined by the following parameters: K?1 and K?2 reflection resolution and its intensity within high Bragg angles; S content to Fe content ratio; the arsenic content and the local variation in its concentration within the pyrite grain; the size of submicroscopic blocks and the crystal lattice disturbance value. The performed analysis showed some relationships between these parameters and refractoriness of the pyrite concentrates. It was observed that at S/Fe ratio close to or higher than stoichiometry and at a low arsenic content (less than one per cent) pyrite concentrates were not refractory. The analysis results showed that concentrates of the Beryozovskaya gold plant (0.02~0.07 As%) and concentrates of the Kommunarovskaya gold plant (less than 0.05 As%) as well as some pyrites from the Sukhoi Log gold deposit had the same characteristics. It was found that average arsenic content did not excess 0.2 per cent. Arsenic distribution within the grain of all these pyrites was uniform. At S/Fe ratio lower than or close to stoichiometry and at high arsenic content (more than one per cent) and significant variation in its distribution within a pyrite grain the pyrite concentrates are refractory. Such pyrites are typical for the Sukhoi Log, the Bakyrchik and the Mardzhanbulak gold deposits. Direct correlation between arsenic and gold contents, in particular, in fine grains of pyrite was observed by many researches. This correlation was explained by impregnation of arsenopyrite which normally contains more gold than arsenic pyrites. The analyses results showed that no arsenopyrite impregnation was found: arsenic distribution within the grain was uniform but its concentration varied greatly. Such pyrite concentrates are more refractory. This paper presents the results of analyses of sulfides to determine the amenability of the associated gold recovery by hydro- and pyrometallurgy.

Jan 1, 2014

Jan 1, 1883

By Carolina Achiardi, Álvaro Videla

"In pre-design a flotation plant copper sulphide is useful to apply a simplified methodology of economic analysis that relates the size of the grinding product (P80) with the throughput and their effect on copper grade and recovery of copper in the final concentrate of a flotation circuit. With this objective, this methodology covers the following analysis, perform by evaluation of five sizes grinding products (P80): 120, 150, 180, 210 and 240 microns. • Flotation testwork (rougher kinetic, open and closed cycle test) has been done to determinate the optimum operating conditions and to estimate the maximum recovery of copper in the concentrate, using Klimpell model • Flotation plant design assumes a conminution product obtained from a 25,000 HP ball mill • Metallurgical balance is performed for the circuit based on flotation testwork • Economic evaluation by calculating capital expenditure (CAPEX), operating expenditure (OPEX) and sales revenue, to determine NPV is performed and relates to the NPV. An optimum grind size is then obtained based on cash flow. The results shows a grinding product size that optimizes flotation and allows a higher NPV and INPV over other alternatives."

Jan 1, 2014

By J. B. Hiskey, W. J. Schlitt, W. G. Pitt

Aqueous SO2 (sulfurous acid) is an interesting chemical compound. It functions as a reagent in various hydrometallurgical systems, but also represents an undesirable constituent in gyro- and hydrometallurgical effluent solutions. When present in such streams, SO2 can be oxidized to the more stable sulfate form to avoid exsolution of SO2 as a source of fugitive emissions and to simplify standard water treatment plant operation. This study provides information on the stoichiometry, kinetics, and mechanism of SO2 oxidation using oxygen and an iron salt catalyst with solutions containing 0.05-20 g/L (0.002-0.7 oz per gal) SO2. The effects of iron salt concentration, oxygen pressure, temperature, degree of agitation, and pH on SO2 oxidation are also described.

Jan 1, 1984

By E. V. Potter

"INTRODUCTION The oscillator and amplifier system described in this paper was developed specifically for driving sound generators of the type developed by H. W. St. Clair and described by him in an article 3/ published several years ago in the Review of Scientific Instruments.Nevertheless, with little or no alteration it can be used to drive any vibrating system in which the vibrating member must be driven at its resonant frequency; the only restrictions are that the driving mechanism be electrical in nature and that the vibrating member be accessible so that some type of pick-up can be coupled to it. Operation of the automatic frequency-control element in the oscillator, however, depends entirely on the operating characteristics of the vibrating member; therefore, in order to completely explain the operation of the circuit, it will be necessary to describe the construction and operation of the vibrator used with it. Only the essential features and characteristics of the vibrator will be described in this article, and the reader is referred to St. Clair's 4/ report for further details."

May 1, 1943

By S. G. Sawyer

The Pittsburgh Safety and Health Technology Center (PSHTC) of the Mine Safety and Health Administration (MSHA) provides engineering and scientific support to the inspectorate personnel of MSHA. One of the Center's myriad roles is to assist in the investigation of mining accidents, especially those involving fatalities. Center personnel utilize forensics to help uncover the causes of accidents and to make technical recommendations on the prevention of future similar mishaps. To exemplify a typical forensic investigation, this paper documents the methodology used in determining the reasons for a boat sinking, which resulted in a double fatality on a mine company pond.

Jan 1, 1997

By A. G. H. Andersen, A. W. Kingsbury

SILICON bronzes containing iron are used to a considerable extent in industry, under the trade name of P.M.G. alloys. Various classes of wrought alloys fall in the composition range 1.5 to 3.5 per cent silicon, and 0.5 to 2.5 per cent iron. Castings may contain as much as 6 per cent silicon and 3 per cent iron at present. The constitutional diagrams of these alloys are thus of considerable practical importance. Copper-silicon-binary alloys have been thoroughly investigated by a number of workers, the latest reports being those of C. S. Smith1 and of A. G. H. Andersen.2 Although much work has been done on iron-copper alloys,3 recorded investigations on the copper-rich copper-iron binary constitutional diagram are not numerous. Tammann and Oelsen4 determined the solubility limits of iron in copper by means of magnetic measurements, and found that the solubility of iron in copper amounts to a fraction of one per cent at 400°C., increasing slowly to one per cent at 800°C. From 800°C., the solubility increases rapidly and attains 4 per cent at 1100°C. Hanson and Ford,5 using electrical resistivity measurements and the microscope, determined a somewhat different solubility limit. Of earlier X-ray works on the copper-iron system, very little has been published. The work by Bradley and Goldschmidt6 on copper-iron-aluminum alloys includes some information on the copper-iron binary. These investigators conclude that substitution of iron in the copper lattice decreases the spacings, which is contrary to the evidence of the present work. Hanson and West7 have investigated the ternary alloys of copper with iron and silicon. Although their diagrams are valuable contributions to the understanding of these alloys, they did not recognize the kappa phase,12, 7,8 and their diagrams do not everywhere conform to the phase rule. The present work contains a check by means of X-rays of the solid solubility limit of iron in copper, and an X-ray investigation of the ternary-phase diagram, which, owing to present conditions, it became necessary to curtail considerably. PREPARATION OF SAMPLES Castings weighing about 75 grams were melted under vacuum. The charges were made up of ingot iron, copper cathodes from Laurel Hill, and refined silicon supplied by the Electrometallurgical Co. Alundum crucibles were generally used. The exceptions were alloys 77 and 78, which were melted in graphite crucibles. The ingots were annealed at 800°C. for one week, then samples were cut for chemical analysis. Longitudinal sections of the binary alloy ingots were hammered into plates 3 in. thick. Wherever possible, these plates were homogenized at temperatures ensuring

Jan 1, 1942

By A E. Annels, G F. Johansen, B W. Cuffley

Nuggety gold-quartz reefs are characterised by localised, high-grades and in many cases coarse free-gold. Geometrical and grade complexities are often observed. The high-grade regions are generally erratic and have a low continuity; though may make the deposit economic. Viable grades are generally contained within discrete oreshoots, which are surrounded by barren/low-grade material. Drilling is an effective measure of geological continuity, however grade distribution can only be reliably obtained from underground development and bulk sampling. In general terms, only an inferred resource is likely to be estimated from surface drill data alone. Underground development, further drilling and probably bulk sampling will be required to delineate inferred and indicated resources. Closely spaced development with bulk sampling is likely to be the best way to determine a probable reserve. The resource evaluation process must driven by a clear geological model that should attempt to understand the controls to reef geometry and grade distribution. Geological interpretation has traditionally been undertaken in two-dimensions, though computer software is now being used to produce three-dimensional models. Grade interpolation has generally been undertaken using classical methods, typically weighted averages, zone of influence weighting and polygonal/sectional blocks. Tonnages can generally be calculated from diamond drill and development information with a reasonable degree of confidence. Grade is much more difficult to define with confidence because of its highly erratic and discontinuous nature. To account for variability it is recommended that a best estimate be reported within a grade range, as this more accurately reflects the uncertainties involved. Reporting should be undertaken within the framework of the JORC code, but should involve special consideration of grade reliability.

Jan 1, 2000

By A. C. Fieldner, Lester L. Hirst, Henry H. Storch

Experimental work on liquefaction of coal was taken up by the Bureau of Mines in 1936 when it became evident that a prudent policy from the national point of view should include preparation for the time when gradual exhaustion of petroleum resources would require supplementing the growing demand for motor fuel with gasoline and diesel oil from coal. At that time (1936) certain foreign nations that had no home sources of petroleum, especially Germany, England, and Japan, were conducting active research and at least two of them were producing liquid fuel from coal on a commercial scale. Germany was reported to have an annual producing capacity of 800,000 metric tons of gasoline per year, and England had just put into operation the Billingham plant of Imperial Chemical Industries for the hydrogehation of bituminous coal and tar by the Bergius-I.G. process. The annual capacity of this plant was about 150,000 long tons of gasoline per annum (3500 bbl. per day). With these developments taking place in foreign countries, it seemed important to undertake a long-range program of fundamental research in this country to establish a sound groundwork for the evaluation of foreign work on synthetic liquid fuels and at the same time to obtain data on the oil yields and operating difficulties using various kinds of American coals and lignite to the hydrogenation process. The results of such research would be useful in determining the yields and quality of liquid products obtainable from various coals so that American industry would be in position to select the most suitable coals and make rapid progress in establishing this new industry when the commercial need should arise. It was hoped, also, that progress in a better understanding of the chemistry of coal hydrogenation would reduce the cost of the process materially. To carry out this program, a small continuous unit capable of hydrogenating 100 Ib. of coal in 24 hr. was installed at the Central Experiment Station of the Bureau of Mines at Pittsburgh, Pa. Small steel autoclaves or bombs of 0.3 gal. (1.2 liters) capacity also were used for batch-hydro-genation experiments in the study of the chemical fundamentals of the process. Much valuable assistance was obtained in planning the experimental program and designing the equipment from the Fuel Research Station of Great Britain and the Fuel Laboratories of the Mines Department of Canada, where such investigations had been in progress for several years. Equipment and General Procedure of Research The industrial liquefaction of coal by the Bergius-I.G. hydrogenation process as practiced at Billingham, England, from

Jan 1, 1944

By Lester L. Hirst, Henry H. Storch, A. C. Fieldner

Experimental work on liquefaction of coal was taken up by the Bureau of Mines in 1936 when it became evident that a prudent policy from the national point of view should include preparation for the time when gradual exhaustion of petroleum resources would require supplementing the growing demand for motor fuel with gasoline and diesel oil from coal. At that time (1936) certain foreign nations that had no home sources of petroleum, especially Germany, England, and Japan, were conducting active research and at least two of them were producing liquid fuel from coal on a commercial scale. Germany was reported to have an annual producing capacity of 800,000 metric tons of gasoline per year, and England had just put into operation the Billingham plant of Imperial Chemical Industries for the hydrogehation of bituminous coal and tar by the Bergius-I.G. process. The annual capacity of this plant was about 150,000 long tons of gasoline per annum (3500 bbl. per day). With these developments taking place in foreign countries, it seemed important to undertake a long-range program of fundamental research in this country to establish a sound groundwork for the evaluation of foreign work on synthetic liquid fuels and at the same time to obtain data on the oil yields and operating difficulties using various kinds of American coals and lignite to the hydrogenation process. The results of such research would be useful in determining the yields and quality of liquid products obtainable from various coals so that American industry would be in position to select the most suitable coals and make rapid progress in establishing this new industry when the commercial need should arise. It was hoped, also, that progress in a better understanding of the chemistry of coal hydrogenation would reduce the cost of the process materially. To carry out this program, a small continuous unit capable of hydrogenating 100 Ib. of coal in 24 hr. was installed at the Central Experiment Station of the Bureau of Mines at Pittsburgh, Pa. Small steel autoclaves or bombs of 0.3 gal. (1.2 liters) capacity also were used for batch-hydro-genation experiments in the study of the chemical fundamentals of the process. Much valuable assistance was obtained in planning the experimental program and designing the equipment from the Fuel Research Station of Great Britain and the Fuel Laboratories of the Mines Department of Canada, where such investigations had been in progress for several years. Equipment and General Procedure of Research The industrial liquefaction of coal by the Bergius-I.G. hydrogenation process as practiced at Billingham, England, from

Jan 1, 1944

By Lester L. Hirst, Arno C. Fieldner, Henry H. Storch

EXPERIMENTAL work on liquefaction of coal was taken up by the Bureau of Mines in 1936 when it became evident that a prudent policy from the national point of view should include preparation for the time when gradual exhaustion of petroleum resources would require supplementing the growing demand for motor fuel with gasoline and diesel oil from coal. At that time (1936) certain foreign nations that had no home sources of petroleum, especially Germany, England, and Japan, were conducting active research and at least two of them were producing liquid fuel from coal on a commercial scale. Germany was reported to have an annual producing capacity of 800,000 metric tons of gasoline per year, and England had just put into operation the Billingham plant of Imperial Chemical Industries for the hydrogenation of bituminous coal and tar by the Bergius-.I.G. process. The annual capacity of this plant was about 150,000 long tons of gasoline per annum (3500 bbl. per day). With these developments taking place in foreign countries, it seemed important to undertake a long-range program of fundamental research in this country to establish a sound groundwork for the evaluation of foreign work on synthetic liquid fuels and at the same time to obtain data on the oil yields and operating difficulties using various kinds of American coals and lignite to the hydrogenation process. The results of such research would be useful in determining the yields and quality of liquid products obtainable from various coals so that American industry would be in position to select the most suitable coals and make rapid progress in establishing this new industry when the commercial need should arise. It was hoped, also, that progress in a better understanding of the chemistry of coal hydrogenation would reduce the cost of the process materially. To carry out this program, a small continuous unit capable of hydrogenating 100 lb. of coal in 24 hr. was installed at the Central Experiment Station of the Bureau of Mines at Pittsburgh, Pa. Small steel autoclaves or bombs of 0.3 gal. (1.2 liters) capacity also were used for batch-hydrogenation experiments in the study of the chemical fundamentals of the process. Much valuable assistance was obtained in planning the experimental program and designing the equipment from the Fuel Research Station of Great Britain and the Fuel Laboratories of the Mines Department of Canada, where such investigations had been in progress for several years. EQUIPMENT AND GENERAL PROCEDURE OF RESEARCH The industrial liquefaction of coal by the Bergius-I.G. hydrogenation process as practiced at Billingham, England, from

Jan 1, 1944

By A. Beeby Thompson

FOR more than 2500 years, natural gas issues in the Surakhany district of the Apsheron peninsula were the object of pilgrimages by fire worshippers and Hindoos from Burma and India. Even as late as 1890, Hindoo priests conducted ceremonies in a temple at Surakhany, which probably replaced a more ancient one; but later, the visits of the pilgrims were prohibited in order to check the spread of Asiatic diseases in that region. For centuries, limited supplies of oil have been abstracted from shallow excavations in the Caspian oil belt and dispatched into the interior of Asia and elsewhere for medicinal and industrial purposes. Statistics show a yield of 37,400 bbl. in 1863, but only since 1869 has there been serious development; in that year the yield was 203,000 bbl. At that time, hand digging was supplanted by drilling, and the enormous wells that resulted from tapping sources hitherto beyond the reach of operators completely demoralized the industry for a time, owing to inadequate outlets for the products. The early activities in this area were greatly hindered by annoying taxation, monopolies, imperial land grants, etc., but when these were revoked or adjusted, in 1877, the industry sprang into prominence and, between 1898 and 1901, the Baku fields produced practically one-half of the world's supply of oil. Within a few miles of Baku lie the two richest oil fields in the world; viz., the Balakhany-Saboontchy-Romany and the Bibi-Eibat, the latter constituting almost a suburb of the city. For many years the gasoline obtained in the refineries of the Baku area was burned in pits, being considered an undesirable product, and until 1870 the residue also was destroyed, its value as a fuel not being recognized. Kerosene was the main product sought by the refiners. It was shipped across the Caspian Sea and up the Volga to the industrial centers of Russia. Only on the completion of the Baku-Batoum railway did the Baku oil fields secure

Jan 8, 1920

By Glenn A. Hazen

This report presents a stress investigation of four coal pillars located under two depths of cover. Each coal pillar was instrumented with ten load cells designed to measure coal pressure during initial and secondary mining. The problem considered was one of uniform triaxial stress as a large coal pillar was loaded under a thick limestone bed. Special attention was given to pillar design procedure. Unconfined uniaxial compression tests were conducted for coal specimens 7/8 in., 2-1/8 in., 3 in., and 4 in. square with length to square side ratios of 1/2, 1, 1-1/2, and 2. Stress-strain curves were recorded. Six specimens were tested at each size. Results show that a coal pillar is composed of an inner zone which is highly loaded plus a region around its perimeter which has lost its elastic strength. The bearing capacity of a coal pillar consists of elastic and crushed coal response: The failure strengths have been determined and will be useful in coal recovery, mine design, and mine safety.

Jan 1, 1975

By Craig J. Nelsen, J. Leroy Schutz

The Carache Canyon Prospect consists of a hypabyssal breccia pipe which intrudes a gently dipping sequence of Cretaceous Mancos Formation and Mesa Verde Group shales and sandstones. This sedimentary sequence is intruded by a number of Oligocene (34-30 Ma) calc- alkaline sills. The formation of the breccia pipe and its subsequent gold mineralization is related to the emplacement of an alkaline intrusive complex dated between 30-26 Ma. An exceptionally large block within the pipe provides compelling evidence that brecciated sills and sedimentary rocks form a relict stratigraphy that collapsed 400-800 ft (120-240 m) below their counterparts outside the pipe without substantial changes in stratigraphic position. Native gold and sulfide mineralization within and around the pipe occurs in fractures that are primarily controlled by competency differences between sills and sedimentary rocks and secondarily controlled by ductility contrasts between the relatively brittle Mancos Formation hornfels and the more ductile Menefee Group shales. The resulting pattern of gold mineralization is a series of stacked, tabular, mineralized sills and sandstone separated by barren shale in an annular region along the southwest margin of the pipe. A series of near-vertical, subparallel, sill and sandstone breccias separated by barren or weakly mineralized shale breccia occur within shallow levels of the pipe.

Jan 1, 1990

By LEONARD S. AUSTIN

THE works of The Boleo Mining Co. are situated at Santa Rosalia, Lower California, on the opposite side of the Gulf of California from Guaymas, the, nearest railroad town. The copper deposits were discovered in 1868, and the name Boleo arose from the fact that the ore particles were agglomerated as little balls of carbonate or oxychlorides of copper. When worked on. a small scale, only ore carrying 20 to 25 per cent copper was mined; this was shipped to Europe for reduction In 1884 The Boleo Mining Co. was organized and,-the mine put in condition. Even then, due to the low price of copper, only the richer ore continued to be shipped. To operate the mine successfully the company made radical changes in the methods of development and spent money freely for construction of adequate plants for the treatment of low-grade ore. Finally, the owners of the various adjacent mining claims combined their interests and formed a joint enterprise attractive to French capital.

Jan 1, 1929

By Ott F. Heizer

This paper describing the mining practices at the mines of Massachusetts, Massachusetts Co., Inc., at Mill City, Nev., is one of a series being prepared by the Bureau of Mines on mining practices, methods, and costs in tie various mining districts of the United States. The author acknowledges the assistance of William C. Vanderburg, associate mining engineer, U. S. Bureau of Mines, in the preparation of this paper.

Jan 1, 1930

[Abbott, Jay Union Supply Co., 7458 So. Jackson Street, Littleton, CO 80122 Achziger, Ronald H Midwest Rubber & Supply Co., 6404 E. 39th Ave., Denver, CO 80207 Acre, Leland H Dorchester Coal Co., 2795 Skyline Ct., Grand Junction, CO 81501 Adams, Dell H Consolidation Coal Co., Consol Plaza, 1800 Washington Rd., Pittsburgh, PA 15241 Adams, Robert W Energy Fuels Corp., 3 Park Central, Suite 900, Denver, CO 80202 Adams, Douglas K General Electric Co., P.O. Box 2331, Denver, CO 80201 Adams, William R ATW, Inc., 760 Three Fins, Dr. #106, Murray, UT 84107 Adsero, Richard Falkirk Mining Co., Box 1024, Washburn, NO 58577 Afflect, Robert S Anderson Mavor (U.S.A.), Ltd., 303 Progress Street, Zelienople, PA 16063 Agee, Pete Driltech, Inc., P.O. Box 338, Alachua, FL 32615 Ahlborg, William Joy Mfg. Co., 26 Sedgwick Dr., Englewood, CO 80110 Ainscough, Harlen R D. H. Emling Co., 5500 S. Syracuse Cr. #118, Englewood, CO 80111 Aitken, Don Goodyear Tire & Rubber Co., Box 15256 Trontwood, Spokane, WA 99215 Alexander, Doug A C. W. Silver Co., Inc., 761 So. 7th, Grand Junction, CO 81501 Alison, David R Amoco Minerals Co., 6900 S. Yosemite St., Suite 150, Englewood, CO 80112 Alke, R. J Westinghouse Elec. Corp., 55 West 5th Ave., Denver, CO 80204]

Jan 1, 1981

By Marc Symbaluk

Core Programs Current ? Aboriginal Involvement Program ? Adaptive Forest Management / Forest History Program ? Grizzly Bear Research Program ? Natural Disturbance Program ? Foothills Growth and Yield Association ? Foothills Stream Crossing Program ? Fish and Watershed Program ? Caribou Landscape Management Association ? Social Science Program ? Local Level Indicators Program ? Communications and Extension Program ? Geographic Information Systems Program ? Mountain Pine Beetle Ecology Program In Development ? Climate Change Program ? Forest Community Program ? Water, Quantity and Quality Program (Water for Life) ? Circumboreal Initiative ? Yellowhead Ecosystem Management Group

May 1, 2008