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Zinc is just now a very important metal. Its use in cartridges and shrapnel brass are in the public eye. But its uses after the war are no less important. Brass as an engineering material for electrical machin-ery, journal bearings, and plumbing fixtures takes fully 50 per cent. of the production, and its use in these lines would have been increased in the last few years but for the price. Its use for barbed wire is probably more in war time than in peace. In the composition of paints, it is becoming more and more necessary. One of the forms of pigment, litho- pone, is the base of nearly all interior wall paints; of all the sanitary enamels for bath-rooms and bath-tubs, and is now in great demand. Zinc oxide is also increasing in use for paint, and for manufacture of linoleum. When we realize that this district-Missouri, Oklahoma, Kansas and Arkansas-produces now over one-third of the zinc ore of the world, it is at once seen that a meeting where the geology, mining, concentration

Jan 6, 1917

By Abdullah Arik

An ore reserve block model is the basis for various decisions in mine development and production. The block model is initially built using the information from the drillhole data only. Once the mine is put in operation, the information from the blasthole data becomes available. Since the spacing of the blastholes are much closer than the exploration drillholes, the blasthole data gathered from the mine over the years become quite extensive containing valuable information about the deposit. In practice, the information from the blastholes is the basis of determining the ore and waste boundaries between and within mining blocks. In an ore reserve model, the valuation of blocks on and close to the pit face can obviously be improved by using blasthole data from neat by drilled and mined-out blocks in addition to using the widely spaced drillhole data. The ideal basis on which to integrate blasthole and drillhole data is to use cokriging.

Jan 1, 1996

By J. Andersen

The very large quantities of energy used for size reduction in the minerals processing industry necessitate the accurate prediction of comminution machine power draw for optimum plant design. The JKMRC has developed effective models for predicting ball mill, autogenous mill, semi- autogenous mill and crusher power draw. When combined with comminution models they provide a powerful tool for evaluating not only the size reduction performance of a plant design, but its power utilization efficiency as well. This paper describes the structure of the mill and crusher power models. Data from a wide range of equipment types are presented which illustrate the accuracy of these models.

Jan 1, 1992

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNS Chairman. JOHN H. JANEWAY, Vice-Chairman. F. E. PIERCE, Secretary 35 Nassau St., New York, N. Y. P. A. MOSMAN, Treasurer. LEWIS W. FRANCIS. BENJAMIN B.. LAWRENCE. Boston Meets first Monday of each winter month. HENRY L. SMYTH, Chairman. ALFRED C. LANE, Vice-Chairman. HENRY A. WENTWORTH, Secretary-Treasurer, 60 India St., Boston, Mass. A. H. EUSTIS, F. G. STANTIAL. Columbia Holds four sessions during year. Annual meeting in September or October. STANLY A. EASTON, Chairman. FREDERIC KEFFER, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. D. C. LIVINGSTON, FRANK A. ROSS.

Jan 5, 1916

By C. F. de Mendonca, T. Kater, R. P. de Souza

Since 1976, Cia Vale do Rio Doce (CVRD) has carried out tests to develop a type of pellet made with an organic binder. Peridur is one binder that showed it could be used in industrial plants. Extensive tests were run in CVRD's pilot plant. The results are presented in this paper. The decision was made to carry out an industrial production of 50 ht (55,000 st) of pellets. The results are shown in this paper. No detrimental effects of the Peridur were observed in either the process or in product quality.

Jan 1, 1985

By William E. Ford, Edward Salisbury Dana

The Niobates (Columbates) and Tantalates are chiefly salts of metaniobic and metatantalic acid, RNb2O6 and RTa2O6; also in part Pyroniobates, R2Nb2O7, etc. Titanium is prominent in a number of the species, which are hence intermediate between the niobates and titanates. Niobium and tanta¬lum also enter into the composition of a few rare silicates, as wöhlerite, låvenite, etc. The following groups may be mentioned: The isometric PYROCHLORE GROUP, including pyrochlore, microlite, etc. The tetragonal FERGUSONITE Group, including fergusonite and sipylite. The orthorhombic COLUMBITE Group, including columbite and tantalite. Also the orthorhombic SAMARSKITE GROUP, including yttrotantalite, samarskite, and ånnerodite. The species belonging in this class are for the most part rare, and are hence but briefly described.

Jan 1, 1922

By M. Allingham

This paper examines the contribution which econometric methods may be expected to make to the specification of commodity agreements, and how in turn computer methods may help in this. Starting from the specification of a model, the paper examines four activities: estimation of the unknown parameters; analysis of the properties of the model; simulation experiments with the model; and control of the model. In each of these activities the basic methodology is outlined, and the contribution of computer methods assessed.

Jan 1, 1977

By Ta M. Li, John D. Wiebmer

Record high prices, burgeoning exploration programs, mine-mill openings, and plant expansions have all characterized a dramatic: resurgence of the US uranium industry in recent years. But while the bull is leading the way on the production side of the nuclear fuel cycle, there is reason for caution from the end-users' viewpoint. How fast will electrical demand grow in the years to come, and what portion of that will nuclear generators supply? How do utilities play their cards when the government holds two of the largest jokers in the deck-a policy on spent fuel reprocessing and a timetable for the fast breeder reactor? Is there a shortfall in domestic uranium supplies on the horizon?

Jan 10, 1978

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNS, Chairman. PERCY E. BARBOUR, Vice-Chairman A. D. BEERS, Secretary, 55 Wall St., New York, N. Y. C. A. BOHN, Treasurer. JOHN V. N. DORR, LEWIS W. FRANCIS. Boston Meets first Monday of each winter month. W. E. C. EUSTIS, Chairman. R. L. AGASSIZ, Vice-Chairman: E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman. OSCAR LACHMUND, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON, S. SHEDD.

Jan 2, 1917

By Wilhelm J. Kogelmann

The concept and operation of novel shaft sinking systems utilizing roadheader-type cutter booms, including mucking, conveying, and hoisting installations, are described. Selection criteria, performance data, and economic considerations for various shaft excavators are presented. Various applications of this low-cost and flexible system for civil engineering and mining projects will be discussed. The cutter booms can work in both soft ground and competent rock. Furthermore, the novel excavator can operate in ground stabilized by grouting, cementing, and freezing. The flexible cutting system can be used both for excavation of shafts, foundation pits, slopes, and for tunneling (drifting).

Jan 1, 1989

By N. J. Themelis, R. V. Flint

In a four-year period between 1973-76, the Metal Mining Division of Kennecott Copper Corp. conducted a company-wide program of operations improvement which involved line and staff personnel from all company functions. Specialist teams performed detailed studies of all operational aspects at Kennecott's four copper mines and concentrators, four smelters, and two electrore-fineries. The specific recommendations that resulted may transform the Metal Mining Division into the country's lowest cost producer of copper by the mid-1980s. In this article, N. J. Themelis and R. V. Flint describe the mechanics of MMD's integrated approach to operations improvement.

Jan 6, 1979

The production of copper by the Outokumpu direct blister process commenced in July 1988. The problems and incidents encountered in commissioning the main smelter equipment are outlined. Early difficulties were encountered in process control, hot metal handling, dust buildup in the off gas handling equipment, waste heat boiler tube failures, foam over of hot metal into the waste heat boiler and failure of ancilliary equipment.

Jan 1, 1989

By J. D. Miller, Z. S. Nickolov

Sum Frequency Spectroscopy (SFS) is a powerful nonlinear optical technique to study interfaces at the molecular level. SFS has one major advantage over conventional vibrational spectroscopic methods, such as infrared (IR) absorption and Raman scattering, in that the method is inherently interface specific. As a result, the spectroscopy of molecules residing in the interfacial region can be probed selectively without any contributions from the molecules present in the more pervasive bulk phases. Analysis of SF spectra can yield information on population, structure, and orientation of interfacial species with several nanometers in-depth resolution. The recently acquired SF spectrometer at the University of Utah opens new possibilities for investigation of interfacial phenomena of great importance for separation technology, materials research, nanotechnology, bioengineering. Its application to studies of liquid/gas, solid/liquid, and solid/gas interfaces will be discussed.

Jan 1, 2004

By Barry T. Kilbourn

There is a continuous quest for better-performing materials, for example, to withstand higher temperatures, to resist more efficiently degradation or to be electrically conductive under extreme conditions. The oxides, and similar compounds, of the lanthanides and yttrium can, in some cases, help provide such behavior. Other advanced materials, such as hydrocarbon catalysts, optical ceramics or sensitive phosphors, may also require these oxides for some essential function. The role of the oxides in a wide variety of technologies, some novel and developing, will be reviewed and the underlying physico-chemical principles, the common threads, between several less well-known and apparently unrelated uses discussed.

Jan 1, 1989

By Bruce Short

HIGH rock and surface temperatures combined H with small deep shafts create a difficult ventilation problem. At the Magma operation in Superior, Ariz., booster fans take air off the bottom levels, directing it first through cooling coils and then through the working places and out to the exhaust shafts. All air drawn from the intake shafts below the 3400 level is cooled before it goes to the stoping areas. Most of the ore mined at Magma has come from steep-dipping vein deposits developed for a maximum distance of 9000 ft along the strike of the vein. At present approximately one third of the tonnage is coming from a new section of the mine where the ore occurs as replacement deposits along a favorable horizon in limestone beds. The deepest mining level is now the 4800.

Jan 3, 1957

By L. B. Pankratz

The Bureau of Mines conducted heat-content measurements above 298.15° K for dehydrated analcite (NaAISi2O6) to 1,000°K, kaliophilite (KA1Si04) to 1,800° K, and leucite (KAlSi206) to 1,800° K. Heat content and entropy increments were tabulated, and the heat content data, were given in equation form. A first order transition was noted for kaliophilite near 810° K with a heat absorption of 160 cal/mole. Leucite had a second order transition which became complete near 955° K. In this transition a crystal change occurred from tetragonal (low-temperature form) to cubic (high-temperature form).

Jan 1, 1968

By Joseph W. Mills

In 1956 the discovery of nickel on Jumbo Mountain, Snohomish County, Washington, focused attention on this part of the Cascade Range, far more renowned for its timber than for its mineral resources. Hand specimens assaying as high as 13 pct Ni encouraged Discovery Mines Inc. of Mount Vernon, Wash., to stake 12 claims in Township 31 North, Range 9 East of the Willamette Meridian. The property was leased to Climax Molybdenum Co. in January 1957. Trenching, sampling, and geologic studies were carried out during the late summer of 1957 when most of the snow had disappeared. Although the deposits are only about four miles south of the logging town of Darrington and about two miles, as the crow flies, southeast of the end of a good gravel road from that town, all camp supplies and equipment were air-dropped, owing to the extremely rugged nature of the terrain.

Jan 3, 1960

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, JR., Chairman EDGAR RICKARD, Vice-Chairman D. MI. LIDDELL, Secretary, 7 Wall St., New York, N. Y. C. A. BOHN, Treasurer JOHN V. N. DORR LEWIS W. FRANCIS Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman JAMES G. CARLETON, Vice-Chairman E. E. BUGBEE Secretary-Treasurer, Mass. Inst. of Technology. Cambridge, Mass. W. E. C. EUSTIS G. A. PACKARD Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman OSCAR LACHMUND, Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON S. SHEDD

Jan 8, 1917

The income of the Institute is derived from dues, subscriptions to MINING AND METALLURGY and sale of publications. These sources are fortunately supplemented by the interest from invested funds now amounting to over $500,000, a considerable portion constituting endowments for especial purposes. Aside from the medal funds the principal endowments are the James Douglas Fund for support of the Library, the Rocky Mountain Fund and the Seeley W. Mudd Memorial Fund. The income from the two last named is available for the support of research and a variety of other purposes. It is allocated by the Board of Directors upon recommendation of standing committees in each case. 'An active effort is being made to increase the endowments of the Institute, it being felt that unusual opportunities exist for research and public and professional service through the organization.

Jan 1, 1934

By Michael G. Nelson, Sekhar Bhattacharyya

Between 1974 and 1977, a detailed study of coal pillar strength was conducted by the University of Utah at the Beehive mine in southeastern Utah. This study was funded by the U.S. Bureau of Mines, and included laboratory testing of coal samples, extensive field instrumentation and measurements, and finite element analyses based on the laboratory results. Recently, a similar analysis of the laboratory results and mine design geometry was completed using the LAMODEL program developed by NIOSH. The results of this analysis were close to the data collected in the field. This study allows comparison with the earlier finite-element analysis, and illustrates the utility of the LAMODEL software suite.

Jan 1, 2005