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Jan 1, 1896

By Harlan Walker

ROCK-DRILL steel has an important bearing on costs in many mining operations, both directly and indirectly. Direct factors include such items as shop expense, steel consumed per ton of ore produced, cost of distribution and the dust hazard. The latter, although no specific amount may be assigned to it, is an ever-present problem, and is receiving increased attention as the science of mining progresses. Indirectly drill-steel performance affects consumption of compressed air, mainte-nance of drills and drilling speed. The latter, in turn, increases or retards the tempo of mining and development. These factors, while not all inclusive, are preponderant in their importance. Thus it is evident that in an extensive operation drill-steel expense may run to many thousands of dollars and that thoughtful research leading toward more efficient practice is warranted.

Jan 1, 1940

Jan 1, 1937

By C. W. Washburne

Professor Lane makes an interesting contribution to the study of cholride waters, in saying that calcium chloride waters occur not only in the greenstones of Lake Superior copper mines, but also in the interbedded felsitic conglomerated and…

Jan 1, 1915

Arizona FRANK A. WARDLAW, JR., Chairman GRANT R. RUBLY, Secretary-Treasurer Miami Copper Co., Box 505, Miami, Ariz. MICHAEL CURLEY C. R. KUZELL BURRELL R. HATCHER A. MENDELSOHN WILLIAM KOERNERA. C. REIFSNIDER Black Hills L. B. EAMES, Chairman ALEXANDER J. M. Ross, First Vice-Chairman FRANCIS CHURCH LINCOLN, Second Vice-Chairman NATHANIEL HERZ, Secretary-Treasurer Lead, S. D. JOSEPH P. CONNOLLY C. N. KRAVIG C. E. DAWSON EDWARD L. TULLIS

Jan 1, 1939

By Edward F. Fitzhugh

QUANTITATIVE appraisal of the chances of finding various tonnages and grades of ore clarifies any exploratory development proposal. Ways are discussed of appraising chances in conformance with probability principles, and graphs are suggested to show tonnages, grades and the corresponding judged expectancies.

Jan 1, 1947

Jan 1, 1961

ARIZONA Established July 10, 1915 ROBERT W. THOMAS. Chairman ROBERT W. HUGHES, Vice-Chairman HUBERT O. WOODS. Secretary-Treasurer American Smelting & Refining CO., Hayden, Ariz. FRANK A. WARDLAW, JR., National Director THEODORE BROOKS I H. C. HENBIE THOMAS C. CHAPMAN P. D. I. HONEYMAN CARL H. COLE JOHN E. LANNING JOHN H. DAVIS ALBERT MENDELSOHN EDWARD G. DENTZER BRENT N. RICKARD MORRIS G. FOWLER F. A. WARDLAW, JR.

Jan 1, 1942

By M. B. Yung

The Fu Chuan district lies near the eastern boundary of Kwang Si province in Southern China and is connected with the coast by the West river and its branches.

Jan 1, 1915

By Mary Sue Coates

Characterization of the rock mass in which deep underground structures are to be located is of critical importance to the feasibility and design of the structures. The process involves areal studies, subsurface exploration and extensive testing to obtain comprehensive data on the rock units which will enclose the excavated structures. The Illinois Deep Hole Project provides an example of characterization of rock at great depth describing the types and variety of tests and studies which were utilized and the results obtained.

Jan 1, 1984

By R. C. Rastogi, F. F. Aplan

The goal of this study is to evaluate the coal flotation process and the interaction of the chemical (reagent) and hydrodynamic (machine, operational) variables as they affect yield, flotation of various sized particles, and sulfur and ash rejection. Coal flotation is found to follow a first order process with the coal floating much faster than either pyrite or ash. This circumstance may be used to achieve gangue rejection during flotation. When floated with MZBC, cresol, or pine oil frothers, coal floats in the size sequence: 108 pm ( - 65 mesh), 589 x 808 pm (88 x 65 mesh), and 1.17 mm x: 589 pm (14 x 18 mesh). However with a substantial amount of fuel oil collector, all particles tend to float roughly in proportion to their content in the feed. An increasing aeration rate was found to be the most important variable in increasing the coal flotation rate. This increase in flotation rate, unfortunately, is also accompanied by an increase in the flotation rate of the pyrite. The rejection of pyrite during coal flotation is best accomplished at low aeration rates, low frother concentrations, and low impeller speeds.

Jan 1, 1986

BRANCH COUNCILS MINING BRANCH R M Foose, Chairman (Industrial Minerals) Carroll A Garner (Coal) J V Beall, Eastern Secretary A B Cunmins (Industrial Minerals) R E O'Brien, Western Secretary E D Gardner (Mining, Geology, and Geophysics) Carroll F Hardy (Coal) Philip J Shenon (Mining, Geology, and Geophysics) R E Byler (Minerals Beneficiation) A C. Callen (Mineral Industry Education) Grover J Bolt (Minerals Beneficiation) R J Lund (Mineral Economics)

Jan 1, 1951

By Robert C. Bates

Is the value of rock sealant on radon control destroyed by changes in barometric pressure? While an article by Dr. Gerald Schroeder in the June 1977 issue of MINING ENGINEERING suggests this, it should be noted this is not necessarily true as the ensuing discussion reveals. Before analyzing the data leading to Dr. Schroeder's conclusions, some comments on their source are needed. The figures were collected during a 1973 US Bureau of Mines test of radon barrier coatings in the Dakota uranium mine near Grants, N.M. Results of that test were reported by Franklin, et al 3,4 in 1975. The mine is essentially dry and ore occurrence is within a lightly cemented, porous medium-to coarse-grained sandstone of high permeability and radon emanation rate.

Jan 12, 1977

ALABAMA Anniston.-Carrington, F. G. Auburn.-Brown, R. L. Battelle.-Green, G. G. Bessemer.-Abbott, C. E. Dobbs, G. G. Ferguson, V. Birmingham.-Adams, J. H. Aldrich, T. H. Aldrich, T. H., Jr. Allen, A. W. Bonnyman, J. Bowron, J. Bush, M. W. Crawford, G. G. Crockard, F. H. Ellis, E. E. Fairbairn, C. T. Gallacher, J. Geismer, H. S.

Jan 1, 1917

By N. M. Macmillan, R. S. Kalyoncu, A. R. C. Westwood

The environment-sensitive hardness and laboratory-scale rotary drilling behavior of granite, quartz, and feldspar have been studied. By controlling the chemistry of the drilling environment, it is possible to triple the rate of drilling granite. Pre-existing flaws or other microstructural features play a minor role.

Jan 1, 1975

By E. B. Jensen, C. E. Doane, J. F. Pirozzoli

Results of an extensive one-year test of a nonelectric explosives detonating system led to the mine-wide adoption of this system in early 1978. Since that time, further experience with nonelectric initiation has verified the earlier results, which include the following benefits: Electrical insensitivity Improved productivity Cost effectiveness High reliability While electric blasting caps still experience a limited we restricted to trunkline initiation, all heading rounds as well as the bell, undercut, boundary-cutoff, and raise blasting are detonated nonelectrically. The primary blasting agent used at the Henderson mine is AN/FO, and primers are typically one of the following products, depending on applications: PETN, semi-gelatin dynamite, or a nonnitroglycerin water-gel slurry

Jan 1, 1984

Elected Died 1895 *ABBOTT, AI ATTHUR 1908 1882 *ABBOTT, ARTHUR V 1906 1905 * ABE, MASAYOSHI 1909 1903 * ADAMS, CHARLES C. 1905 1905 * ADAMS, WILLAMS 1909 1903 * ADAMS, W. EDWARDS 1910 1884 *ADDY, MATTHEW 1896 1889 * AKERS, WILLIAMS 1906 1894 *ALLEN R B 1896 1905 * ALLEN, R. SCOTT 1906 1874 *AMIOT, H 1892 1886 *AMSLER, CARL 1894 1895 *ÅNGSTROM, CARL 1901 1887 * ARCHBALD, JAMES 1910 1900 * ARLETT, GEORGE H 1906 1895 *ARMSTRONG, JOHN F 1898 1882 *ARNOLDS, HUGO 1886 1875 *ASHBURNER, CHARLES A 1889 1872 *ASIIBURNER, WILLIAM 1887 1883 *ATKINS, C M , JR 1885 1905 * AUSTEN, PETER T 1907

Jan 1, 1917

By J. M. Hodge, M. A. Orehoski

The relationship between hardenability based on a 50 per cent martensite criterion, and that based on higher percentages of martensite in a number of low-alloy steels was discussed in a previous paper by the authors.' It was found that the differences between the hardenability values based on the 50 per cent martensite and full martensite criterions increased as the hardenability increased and that, in the steels of higher hardenability, these differ-

Jan 1, 1947

By M. A. Orehoski, J. M. Hodge

The relationship between hardenability based on a 50 per cent martensite criterion, and that based on higher percentages of martensite in a number of low-alloy steels was discussed in a previous paper by the authors.' It was found that the differences between the hardenability values based on the 50 per cent martensite and full martensite criterions increased as the hardenability increased and that, in the steels of higher hardenability, these differ-

Jan 1, 1947