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By Robert J. Morris, John N. Butler

A series of organic collectors has been developed which successfully float synthetic secondary uranium minerals, such as autunite, carnotite, and torbernite. Recoveries up to 97 pct have been obtained. With cleaning of rougher concentrates, ratios of concentration as high as 15:l are possible on head assays of 0.10 to 0.50 pct U308. Additions of certain base metal salts aid in recovery and materially in- crease the rate of flotation and selectivity of the collectors for the synthetic minerals. Flotation tests on natural uranium minerals have not yet equaled results obtained on the synthetics, although these collectors do give better results than conventional collectors for nonsulfide minerals.

Oct 1, 1956

By Thomas L. Kesler

Lithium raw materials usable with present technology consist of pegmatite ore and shallow evaporite brine. Deposits of these materials occur in many parts of the world. Those advantageously located supply the present lithium industry. Less favorably located deposits will come into production as markets expand and present sources are depleted. In this discussion, materials listed as reserves include fully explored and partly explored deposits. For those closely drilled and assayed, the data provide measurements rather than estimates, and such reserve tonnages are "proved." For deposits partly explored, the data support reserve estimates of "probable" tonnages. Materials lacking exploratory data are classed as resources, and their "possible" tonnages are inferred mostly from indirect evidence and are essentially objectives for exploration. All figures for pegmatite ore apply to total materials in the ground.

Jan 1, 1979

By Henry B. Estabrooks

As was true with many mining companies, the management of Tennessee Copper Co. followed with interest the successful application of AN-FO as an explosive in coal stripping, construction, open-pit mining, and finally in underground salt mines. Since Tennessee Copper's operations required about 1,250,000 lb of dynamite annually, the potential savings in explosives costs that could be realized by switching to AN-FO could not be ignored. From a cautious start, AN-FO is now being used for stoping, development work and secondary blasting in all mines of Tennessee Copper Co. AN-FO accounts for 80% of the explosives used in such work. Fragmentation, fumes, crew acceptance, and cost savings have been quite attractive without any decrease in safety.

Jan 11, 1962

By Satyajeet Ghosh, Edward F. Glynn

Many of the proposed techniques for calculating the reliability of rock slopes utilize Monte Carlo simulation. Monte Carlo approaches are attractive because they provide means of solving probabilistic problems with deterministic algorithms. One disadvantage shared by all simulation-based stability analyses is that they assume all the random variables are independently distributed. The paper focuses on the independence assumption and examines the effect of correlation on the probability of failure. In particular it considers the influence of possible (albeit hypothetical) correlation between joint attitudes [(8)] and joint friction angles [($)]. The study indicates that neglecting correlation can introduce significant errors into the reliability computations. With a modest positive correlation between [8] and [$] the error can lead to a 100% overestimate of the probability of failure.

Jan 1, 1982

By G. E. Kedzie

The ore-deposits of ail that portion of the San Juan country within the borders of Ouray County are either in the tertiary ernptives or, confined to a relatively narrow zone, in the sedimentary beds just beneath them. The ore-deposits in the igneous formation

Jan 1, 1888

By Henry A. Gordon

Under the title " Hysteromorphous" it is proposed to include deposits which have been formed from original deposits by the influences of the surface-region. The term Hysteromorphous—later-formed—has been used by Prof. Posepny, of Vienna, to distinguish secondary from primary deposits and is more comprehensively applicable than the terms or designations hitherto used for the same thing.

Jan 1, 1896

By V. D. Perry

AS the traveler approaches Chuquicamata from the seaport of Antofagasta, crossing in a northeasterly direction the 150 miles of coast range and completely barren pampa with its low, rolling hills and broad depressions, the gradual rise to an elevation of 9000 ft is imperceptible, and it is hard to realize that the smoothly contoured hills east and west of the mine are from 10,000 to 11,000 ft above the level of the sea. The deceptive monotony of the scene is relieved only by the background of an unbroken line of lofty volcanic peaks, part of the Andean Cordillera, which rise, snow covered, against the eastern skyline. The drab geographical foreground is matched by the geological monotony of unaltered, gray rock

Jan 1, 1952

By James Yancik

The Howe Coal Co. is mining the Oklahoma Lower Hartshorne bed which ranges in seam thickness from 38 to 42 in. and pitches approximately 7° to the northeast. The raw feed to the cleaning plant averages about 20% ash and 1.10% sulfur, being reduced in the cleaning process to 4.8% ash and 0.9% sulfur with a free swelling index of 8 or 8%. This coal rivals the Pocohantas seam in chemistry and coking characteristics but has better fluidity than the Pocohantas seam coal. The coal is presently being prepared for the Japanese steel market in an 85-tph pilot plant designed and constructed by Roberts & Schaefer. The cleaning-plant flowsheet is discussed in detail.

Jan 1, 1972

By Robert N. McIndoo

A good tire program must begin at the top; management must have an awareness of the tremendous potential for cost saving that tires represent. At Reserve Mining Co., tires account for 33% of the cost of maintaining its 44 tractor-trailer side-dump haulers and 22% of its 32 rear-dump trucks. In comparison, engine overhauls account for only 6% of the maintenance dollar. Doubling the present engine life would save only 3%. The open-pit mine, located near Babbitt, Minn., moves about 46 million t/y with its off highway fleet. Mine roadways total in excess of 160 km (100 miles) and about 1200 tires are in active use at any given time.

Jan 3, 1978

By M. Katzer, R. Klimpel, J. Sewell

The effect of using selective dispersants as wet grinding aids for ores is demonstrated on laboratory scale batch and continuous grinding equipment. A complete characterization of behavior is performed on a given ore to demonstrate correlations involving torque, % solids, net production rate, and slurry weight and volume loading. The relationship between such laboratory data and industrial scale testing results is very consistent.

Jan 1, 1982

By J. D. Miller, M. B. Mooiman

It has been discovered that gold can be extracted from alkaline cyanide solution with primary, secondary, and tertiary amines by adding certain Lewis base modifiers, such as organic phosphorus oxides. Under these circumstances, gold can be extracted at about pH 10, commensurate with the pH of cyanide leach liquors. The selectivity of the amines and amine/modifier combinations for Au(CN)[2] over other metal-cyanide complexes is discussed. Potential applications for the solvent extraction of gold from cyanide solutions are also discussed.

Jan 1, 1985

By W. E. Wickerman

The Magnetic Storm Monitor is an instrument that continuously records variations in the earth's total magnetic field at a fixed location. It is intended for use in conjunction with airborne magnetometer surveys. There are stormy periods when changes in the earth's magnetic field are so violent that data obtained with airborne equipment would be of little value. The Monitor provides this information so that flights may be cancelled or terminated, thus eliminating useless flying. Moreover, when some unpredictable change in the earth's field occurs during an airborne survey, the Monitor record, showing a similar event, may serve to salvage the data.

Oct 1, 1955

By Christopher Haycocks, J. Richard Lucas

The growth of computer and ground control technology in recent years, combined with an urgent demand for low-cost fossil fuels and mineral resources, has set the stage for full-scale utilization of computers in mine planning. Steeply rising production costs and the need to preserve the environment are placing great demands on engineers to improve their mining efficiencies, which can best be accomplished by applying the full capabilities of the computer. Pressure to develop and perfect programs with an immediate potential for improving mine design, reducing mining costs and extending the viable coal reserves of the country has already come to bear in the form of exploding energy requirements, environmental considerations and the visible limitations of other energy sources.

Jan 4, 1973

By C. F. Chung

This paper will discuss an application of multivariate discriminant analysis to aid in predicting mineral potential from regional geological data and information on mineral deposits, with particular emphasis on the use of the logistic discriminant function. Logistic discriminant analysis is a generalization of standard discriminant analysis in that the discriminant analysis becomes applicable under a much wider class of distributions. As a practical example, the standard multiple discriminant analysis and the logistic discriminant analysis are applied to data from the Bathurst area in the Appalachian region of Canada and the results are compared with one another.

Jan 1, 1977

By Ray W. Amstutz

The shaft was drilled on US government land m the Piceance Creek basin and was funded by the US Bureau of Mines (USBM). It was drilled to 723 m to provide access to rich deposits of oil shale, nahcolite, and dawsonite for geotechnical test work and environmental mining research. Rotary drilling and dual-string, reverse-air, jet-assist circulation methods were used. Drilling required eight months. Site preparation, running, and cementing the casing required another four months. A 2.44-m ID steel welded casing, 508 mm thick was installed and 2.7 kt of cement were slurried and pumped into the annulus.

Jan 1, 1982

(Members are urged to send in for this column, any notes. of interest concerning themselves or their fellow-members.) The following members registered at Institute headquarters during the month of May: Emil Gathmann, Baltimore, Md. Philip Argall, Denver, Colo. Albert H. Fay, Washington, D. C. A. C. Hodge, F.R.G.S., St. Austell, Eng. Alfred E. Barlow, Montreal, Canada. S. M. Marshall, Johnstown, Pa. B. C. Yates, Lead, S. D. Miltiades Armas, Paris, France. Leonard S. Austin, Salt Lake City. Albert Sauveur, Cambridge, Mass. Henry A. Wentworth, Boston, Mass. G. A. Reinhardt, Cambridge, Mass. Frank M. Leland, Mackay, Idaho. Fred Crabtree, Pittsburg, Pa. W. N. Crafts, Cleveland, Ohio. T. A. Rickard, London, England. Louis Hasbrouck, Kingston, N. Y. F. Lynwood Garrison, Philadelphia, Pa. F. V. Desloge, Desloge, Mo. S. B. Christy, Berkeley, Cal. E. C. Templeton, Palo Alto, Cal. H. A. Buehler, Rolla, Mo. L. D. Ricketts, Warren, Ariz. F. W. DeWolf, Urbana, Ill. J. E. Johnson, Jr., Ashland, Wis. Howland Bancroft, Denver, Colo. A. O. Granger, Cartersyille, Ga.

Jan 6, 1913

For the first time in the history of shaft sinking, the concept of mid-shaft loading has been used. By making use of available hoisting capacity during drilling periods, development work on underground hoist chambers and ore-pass and ventilation by-pass systems at Vaal Reefs South gold mine is being done simultaneously with sinking. This factor, together with the unusual configuration and design of the twin-shaft system at Vaal Reefs South, and the use of raise borers in the installation of ore-pass and ventilation by-pass systems, will mean that the shaft will be commissioned at least a year earlier than would have been possible had conventional methods been used. The possibilities of mid-shaft loading in reducing the time normally taken by shaft service development were recognized by Anglo American Corp. consulting engineers and Shaft Sinkers Pty. Ltd., the company which is sinking both shafts at Vaal Reefs.

Jan 1, 1970

By D. Ott

Results of a research project on investment or lost wax casting will be presented. The project was concerned with various aspects of the process as they are typical for the production of jewellery from gold alloys. During these investigations testing methods for investment quality as well as for casting quality and the various process parameters were developed and charateristic defects as they occur in practice were traced back to their origin in the process. Investigated were various static casting and centrifugal casting methods in different atmospheres as well as vacuum casting in devices of different design. It was shown that independent of the method a close control of the many process parameters interfering with each other is essential for a quality casting.

Jan 1, 1984

(This list includes only those who have entered military service within the past month, or whose entry has only recently become known to us; it also includes a few names of those whose titles or assignments have been changed within the month. The last complete list was printed in Bulletin No. 131, November, 1917. A complete Honor List is maintained in the reception room at the office of the Institute.) BANKS, HAROLD P., 2d Lieutenant, Ammunition Train, 2d Division, U. S. A. BARKER, L. M., Co. B., 62d Infantry. BENHAM, W. M., Sergeant, Co. H, 158th Infantry. BOUDWIN, WALKER J., Co. C., 25th Engineers, Camp Devens, Ayer, Mass. BOWLES, MARTIN F., 2d Lieutenant, Co. B., 355th Infantry. BURG, ROBERT S., Instrument Sergeant, Headquarters Co., 340th Field Artillery, N. A. CHALMERS, JOHN W. P.; Signal Depot, Royal Engineers. CHETNEY, P. C., Corporal, 340th Field Artillery, Headquarters Co. CLARK,. WILL L., Federal Fuel Administrator for Arizona. COFFEY, George W., Lieutenant, Engineer Section, Officers' Reserve Corps.

Jan 1, 1918

By J. R. Barrett

Geotechnical techniques to evaluate conditions in underground metalliferous mines change through a mine's development from prefeasibility to remnant mining. The objectives of this paper are to determine the geotechnical requirements of typical underground metalliferous mining projects, to determine any shortfalls in conventional geotechnical techniques in satisfying these requirements, and to determine the costs of such investigations in proportion to the project expenditure. Finally, areas for future research and development are discussed. A group of over one hundred case history studies are examined to generate data on typical mining problems. The case studies include projects at most Australian underground metalliferous mining operations supplemented with case studies in Canada, Africa, Asia and Europe.

Jan 1, 1983