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The Colorado School of Mines, Golden, Colo. M F Coolbaugh, President. Since 1906 the School of Mines has issued a journal, known as the Quarterly of the Colorado School of Mines, which carries many articles on matters of general interest as well as other articles of a technical nature There is no regular subscription price to the School of Mines publications Anyone interested in back numbers should write and find out the conditions under which individual copies may be obtained, whether a price is set on them or whether they are free Some back numbers are not now available but efforts will be made to supply copies from the files of alumni or other friends of the School Vol 23, No. 3 of the Quarterly (July, 1928) is an index of the publications complete from July, 1906 to July, 1928. A selected list of the technical articles appearing in the Quarterly is given here: Vol 3, No. 3, Rare metals. uranium and vanadium, by H. Fleck (1909), vol 3, No 4, Tungsten in Colorado, by H R Van Wagenen, vol 4, No 3, Preliminary report of the radioactivity of the carnotite of southwest Colorado, by H Fleck and W. G Haldane (1909), vol. 8, No 1 (1913), Some recent developments at Leadville, by G. M Butler, vol 8, No. 3, Physiography of

Jan 1, 1933

By K. R. Y. Simha, W. L. Fourney, D. C. Holloway

An experimental investigation was performed to evaluate the role of stress waves in the pre-splitting operation. 3D birefringent Plexiglas models and the dynamic photoelastic technique were used to visualize the stress waves generated by the detonation. Simultaneous as well as sequential detonation of the explosive charges were investigated. The development of fractures and stress waves were recorded using a high speed multiple spark gap camera of the Cranz-Shardin type. The experimental data was analyzed and displayed-on a Lagrangian diagram to present an overall picture of the entire dynamic event. It was repeatedly observed in the tests that the time required for the completion of the pre-splitting operation as practiced in the field is of the same order as that for the transit time for the stress waves between the blastholes thereby revealing the highly elasto-dynamic nature of the event.

Jan 1, 1982

By Ingemar Marklund

This presentation deals with the conditions at IKAB’s mine in Malmberget but also pertains to underground mining in general. GEOLOGY The Malnberget iron ore field is of pre-cambrian age. The wallrock consists of leptites, gneisses and granites, most of them being recrystallized acid and inter- mediate volcanics. The ore-field is strongly folded, with the folding axes plunging to the south. The original orebed is divided into about 20 different orebodies with a strong variation in dip and form. The ore is mainly magnetite. About 1046 of the ore area consists of hematite ore. The phosphorous content is in average 0,8% and the ore is rather course grained. Fig 1. BACKGROUND At LKAB1s mine in Malmberget the sub- level caving method is the main method of mining. Experiments with vein-mining and sub-level stoping are also underway. The present system of mining is already strictly tied up in investments and infrastructure involved in the mining. Fig 2.

Jan 1, 1981

By M. L. Jeremic

The massive Pb-Zn-Ag sulfide ore body is originated at the contact between the porphyry (footwall) and volcanic (hanging wall). The ore zone is folded and refolded, which results in two different structural geometries of the individual ore bodies. This requires both shrinkage and cut-and-fill mining methods. Strong bedrock resists caving after shrinkage stope completion, so high stress zones are developed below and above the mined area. The cut-and fill system has a limited destressing mechanism, where the stope walls with a backfill exhibiting stress close to a primitive one. This results in closure deformation of the open stope walls, yielding deformations of crown pillars and roof falls of the wide stope backs.

Jan 1, 1985

Jan 1, 1899

By K. V. S. Sastry, S. C. Panigraphy, D. W. Fuerstenau

The batch balling behavior of hematite, magnetite and limestone was found to depend markedly on the grinding method used for feed preparation. Wet ground materials require higher moisture for balling than do dry ground materials. Further, as the fineness of the wet-ground material is increased, the overall rate of agglomeration decreases, whereas the opposite is true for dry-ground materials. In contrast, the resulting pellet size distributions are not affected by the nature of the feed material preparation. These differences and similarities in the agglomeration behavior between wet and dry ground materials may result from the hydrophilic/hydrophobic nature of the surfaces, the formation of pre-agglomerates during dry comminution, and possible variations in the packing density of particles in the agglomerates.

Jan 1, 1978

By H. N. Mills

The glass industry is a major user of many industrial minerals in the manufacture of its product. It is the intent of this chapter to: (1) acquaint the reader with the glass industry by including a few production statistics, and then (2) cover the various aspects of the major raw materials used to make glass. Some of the items covered are: type of materials, their function in glass, their composition, cost, and the relative quantity used in glass vs. totals produced. In addition, a discussion of glass raw material specifications, some byproduct materials used in glassmaking, and comments on future prospects related to the environment, technology, and growth are included. The matter of glass compositions, properties, and batches is considered beyond the scope of this chapter which deals only with raw materials. For more details on the particular minerals and rocks, the reader is referred to the commodity chapters in this book.

Jan 1, 1975

By Mario L. Villa

Oil activities and the petroleum industry in general have suffered severely in this country as a result of present war conditions. War has imposed a very heavy and unpleasant burden on the shoulders of those whose duty it is to keep .Argentina supplied with the necessary oil to meet industry's growing demands. Since 1940, imports of manufactured products from Europe and the United States have fallen to a minimum, making it necessary to manufacture as many of them as possible locally. This has brought about the establishment of many new industries and the enlargement of already existing plants, creating new demands for fuel that drain heavily the country's stocks, which already were overtaxed because of the diminished supply imported. To cope with this problem, a plan for an intensification of oil-field activities was drawn up by Yacimientos Petroliferos Fiscales (Argentine Government Oil Fields) which included the drilling of many new

Jan 1, 1943

By A. Eiders

THE year 1874 marks a decided advance in the metallurgy of the West, in two directions. On the one hand, the technical management has been very materially improved, and on the other, the production has been largely increased over that of the previous year. The technical improvements of greatest importance are the introduction of condensation-chambers, or flues, at several works, and the further treatment of the lead matte produced in the ore smelting. These two are of general importance, and although by no means introduced at the majority of works, their adoption at the few where their great importance has begun to be understood will no doubt bring about their universal introduction. To these may be added a third step. forward, which for some localities is vital enough, though for others it must still remain doubtful whether it is to be regarded as an improvement or not. This is the introduction, at several

Jan 1, 1875

By Geoffrey Purcell

Although the extractive metallurgist has not yet tackled the problem of getting blood out of a stone, he must, when faced with the mini- metal values of today's ores, believe that this ultimate miracle will soon be expected of him. Even assuming that some plausible professor at one of the few remaining minerals industry schools could persuade the National Science Foundation to sponsor such a sanguine research project, the funds might have to go begging for want of a graduate metallurgist. Falling enrollment in fields devoted to nonrenewable mineral resources, long a matter of grave concern to educators, is now recognized as a problem of great national consequence urgently needing a solution. While the law of supply and demand might eventually be expected to right the imbalance of engineers, time is not on our side and action to correct the shortage is required now.

Jan 1, 1970

By A. Eilers

The year 1874 marks a decided advance in the metallurgy of the West, in two directions. On the one hand, the technical management has been very materially improved, and on the other, the production has been largely increased over that of the previous year. The technical improvements of greatest importance are the introduction of condensation-chambers, or flues, at several works, and the further treatment of the lead matte produced in the ore smelting. These two are of general importance, and although by no means introduced at the majority of works, their adoption at the few where their great importance has begun to be understood will no doubt bring about their universal introduction. To these may be added a third step forward, which for some localities is vital enough, though for others it must still remain doubtful whether it is to be regarded as an improvement or not. This is the introduction, at several

By B. K. Mozumdar

This paper describes the development and application of a dynamic simulation model of ground movement in an underground mine. Ground movement and related stress distributions with or without stowing are computed as the mining face advances. Pressure profiles plotted for different face positions indicate the presence of a front abutment with a maximum value of four times the original ground pressure but no back abutment in the gob. The surface strain is considerably reduced with increase in packing density in the gob up to a certain value. Beyond this value, the reduction in the strain is minimal, indicating an economic level of packing. As a result of model experiments with different physical systems and geological parameters, it has been concluded that when one of the coordinates for the subsidence and the strain curves is made dimensionless in terms of the critical width, the relationship will hold true for all physical situations. This was in agreement with the NCB observations for different panel lengths.

Jan 1, 1977

By Phil Hulse

The Atlanta mine is located in east-central Nevada, approximately 360 km (225 miles) from Las Vegas. It lies in Lincoln County, 116 km (72 miles) south of Ely and 80 km (50 miles) northeast of Pioche. The property is currently operated by the Standard Slag Co. under a joint venture agreement with Bobcat Properties Inc, of Fort Lauderdale, Fla. Operations began in May 1975, and the mill is currently processing 109 000 to 122 500 t/y (120,000 to 135,000 stpy) of gold- and silver-bearing ore. Open-pit mining takes place in a breccia zone that occurs between Ordovician limestones and dolomites on the footwall and Tertiary rhyolites on the hanging wall. The quartz breccia ore is among the most abrasive in the world-shovel teeth must be replaced every week, 19-mm-thick (3/4-in.) steel chutes last about a month.

Jan 9, 1978

By J. Jay Jacobsen

A dynamic regional coal development model is constructed for the Eastern Powder River Basin of Wyoming. Using this model, alternative development schedules from a recent environmental impact statement submitted to the Department of the Interior are simulated (Ref. 1). These alternatives include different mixes of export capacity, different coal conversion techniques within the region, as well as various levels of coal production. Exportation of 70 to 80 percent of an ultimate coal production of 180 million tons (163.3 x l09 kg) per year and the careful phasing of additional public services with population growth effectively reduce the social and environmental impacts of coal development. The alternative involving the addition of 43,000 megawatts of electrical generation capacity has very significant adverse social and environmental impacts on the region.

Jan 1, 1977

By D. J. Oswald, J. G. Ziegler

It is of common knowledge that loading within a grinding mill, whether ball, rod, pebble, or autogenous, is directly related to the lubrication back pressure developed between the mill journal and bearing shoe during mill operation. The merits of both forced-feed and gravitational-feed bearing lubrication methods are discussed with particular emphasis directed toward their applicability to continuous grinding mill inventory control. Data obtained from wet grinding mill applications in the cement and mining industries is presented to more clearly define the influence of such variables as feed consistency, slurry viscosity, mill retention, bearing oil temperature, grind fineness, and grinding media wear on the measured journal lubrication back pressure during automatic mill feed control. Finally, various grinding mill control schemes for maintaining constant mill loading and consequently optimizing mill operating efficiency are discussed and evaluated as to their advantages and/or disadvantages.

Jan 1, 1974

The following is an incomplete list of members and guests who called at Institute headquarters during the period Oct. 10, 1918 to Nov. 10, 1918. J. Carson Adkerson, Virginia. George H. Parsons, Hayden, Ariz. Andrew B. Armstrong, Connecticut. W. E. Pomeroy, New York. Courtenay DeKalb, San Francisco. Ezra C. Rider, Bisbee, Ariz. Clifford G. Dennis, San Francisco. H. W. Seaman, Chicago, Ill. Rudolph Emmel, Boston, Mass. William Allen Smith, Northampton. Emil Gathmann, Baltimore Md. R. K. Stockwell, Salt Lake City, Utah. Ernest S. Geary, Denver, Colo. W. G. Swart, Duluth, Minn. W. E. Hopper, Washington, D. C. Kirby Thomas, New York. W. Spencer Hutchinson, Boston, Mass. - Warren D. Thompson, Harvard Club. E. W. Kohl, Jr., Philadelphia, Pa. H. Vincent Wallace, Los Angeles, Cal. E. C. Nighman, Butte, Mont. Paul T. Benson, formerly with the Tacoma smelter, has resigned his position there to accept one with the Great Metals Mining and Milling Co. at Nespelem, Wash. Prof. Edward E. Bugbee, of the Mining Department of the Massachusetts Institute of Technology, has been granted a leave of absence to accept the position of Assistant Director of Education for the S.A.T.C. of five southern states with headquarters at Raleigh, N. C.

Jan 12, 1918

By W. A. J. M. Van Waterschoot Van Der Gracht

The commercial production of petroleum in Germany is confined to the North German plain, in the Hereynian foreland, and the intramontane Permian salt basin of Thuringia, south of the Hare Mountains. Petroleum is produced in the former only in connection with salt domes, upthrust through Tertiary and Mezozoic strata of great thickness. In the basin of Thuringia petroleum is found in a Permian dolomite underlying a salt formation. It is exclusively in the peripheric zone of a few of the salt plugs in the North German plains region that commercial oil has so far been developed, notably in the following fields, all in the general region northeast of the city of Hanover: (1) Hänigsen-Obershagen-Nienhagen, south of Celle; producing from horizons in the Upper Triassic, the Middle Jurassic and the Lower Cretaceous; (2) Oberg, south of Peine; producing from horizons in the Middle Jurassic and Lower Cretaceous; (3) Oelheim-Eddesse, north of Peine; producing from horizons in the Upper Triassic, Lower and Middle Jurassic; (4) Wietze, west of Celle, where the main producing horizon is in the Lower Cretaceous. In some of these oil fields production from surface seepages was mentioned as early as 1669 (Oberg). Commercial production of importance dates only from recent time.

Jan 1, 1932

By D. Brion, J. J. Prédali, J. Hayer

The need to grind volcanic-sedimentary ores very finely (d80 < 20 µm) so as to liberate Pb, Zn, and Cu sulfides from their pyritic gangue causes difficulties in selective flotation. The pyrite, which accounts for 70-80% of the mineral content, is insufficiently depressed by the usual pH and NaCN techniques. To determine better depressing methods, the surface evolution of pyrite during flotation was followed by ESCA spectroscopy to compare the stability range in the Eh-pH diagram. Surface iron hydroxide was formed, which is the main pyrite-depressing factor. NaCN appears to play a more restrictive part, since no ferricyanides were detected, except for very small amounts at pH 7.

Jan 1, 1980

By J. B. Evans

Maintaining overall optimum profitability at a mine site necessitates constant reassessment of operating strategies. In essence, each strategy is a particular combination of envisaged capital expenditure, income flow and elapsed time. Selecting a strategy, based on profita¬bility potential requires each contemplated strategy being subjected to discounted cash flow analysis; even with a computer such analysis can be cumbersome. The chapter discusses a &apos;shortcut&apos; technique which assigns profitability rankings to alternate strategies and iden¬tifies those aspects of a. strategy which impact heavily on profitabil¬ity. This technique can yield quick assessments of sufficient accuracy for many operating strategy decisions. taken on site at on-going mines.

Jan 1, 1978

By John F. Havard, Armine F. Banfield

Sooner or later, we all get involved in the economic study and valuation of a mineral deposit. To communicate clearly the necessary information, we must scrupulously use various terms with specific meaning. All these terms-such as ore, exploration, development, production, reserves, proven ore, probable ore, possible reserves, resources, as well as similar terms applying to coal-are continually on the lips of anyone who reports on the economic aspects of a mineral deposit at the exploration, development, and production stages. The meaning of these terms is even more important in feasibility studies to determine whether a deposit should be put into production. Finally, careless use of these terms in reports published for public financing may, and sometimes does, lead to prosecution of the writer for misleading information.

Jan 7, 1975