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By Catherine T. Aimone

Specimens of copper-bearing quartz monzonite were subjected to a plane shock wave simulating high compressional stresses in the proximity of a borehole wall. Fragmentation was studied as a function of stress levels between 1.6 GPa (23 x 104 psi) and 7.3 GPa(105.8x104 psi) and pulse durations ranging from 1.1 µs to 6.9 us. Both explosive pressure and pulse duration were shown to have a strong effect on particle size distribution. While the effect of pressure is well recognized, the effect of pulse duration indicates that ultimate fragmentation increases with the time of application of a plane wave pulse. At high pulse durations, degree of fragmentation is more sensitive to changes in pressure than at low pulse durations.

Jan 1, 1984

By Alfred Weiss

The Daniel C. Jackling Award, established in 1953, is presented for significant contributions to technical programs in mining, geology, and geophysics. This year's recipient, Alfred Weiss, was cited "For his pioneering achievements in applying systems analysis, operations research, and computer methods in exploration, mining, and environmental control; and in disseminating the new technology to the worldwide mining community; and for his lecture, “New Concepts and Tools in Decision-Making.”

Jan 1, 1979

Elected Died 1882 *ABBOTT, ARTHUR V 1906 1903 * ADAMS, CHARLES C. 1905 1884 *ADDY, MATTHEW 1896 1894 *ALLFN R B 1896 1874 *AMIOT, H 1892 1886 *AMSLER, CARL 1894 1895 *ÅNGSTROM, CARL 1901 1895 *ARMSTRONG, JOHN F 1898 1882 *ARNOLDS, HUGO 1886 1875 *ASHBURNER, CHARLES A 1889 1872 *ASIIBURNER, WILLIAM 1887 1883 *ATKINS, C M , JR 1885 1897 *AYERS, WILLIAM 1898 1885 *BABCOCK, GEO H 1893 1884 *BAILEY, EDWARD 1889 1880 *BAILEY, JACKSON 1887 1900 *BALLOU, FRANKLIN 1903 1886 *BARNES, F W 1892

Jan 1, 1910

By H. Xi-Lum

Three rapid cold bonding production methods wing sponge iron powder as a binder for low temperature pellets have been successfully developed. These methods differ from ordinary bonding by the elimination of salt and other catalyzers, equipment corrosion and environmental pollution. Experiments show that these pellets have good metallurgical properties. A semi-industrial test has proven the laboratory results, with the continuous and stable production of metallic pellets. These methods replace traditional high temperature firing of oxidized pellets for direct reduction. As a result, the plant for oxidized pellets can be saved and substituted for grate in the grate-kiln system. Thus, 20% of the investment could be saved, and production cost may also be decreased because the production of cold bonding pellets does not need additional space.

Jan 1, 1984

By E. C. Reed

Ninety wells were completed in Nebraska during 1941, of which 42 were producers. One of them was the discovery well of a new field. All of the production to date is in Richardson County. At the close of the year 14 wells were drilling and three more were shut down for orders, hoping for future development of production. Most of the drilling activity was in Richardson County, which had 68 operations; 10 wells were drilled in Nemaha County, 5 drilled or drilling in Gage County, 3 each in Otoe and Furnas Counties, 2 each in Cass, Harlan, Johnson and Sarpy Counties, and 10 wells were completed or drilling over the remainder of the state. The most important development of the year was the discovery in October of the Barada field, sec. 36, T. 3 N., R. 16 E.,

Jan 1, 1942

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 J. D. Irving

In the summer of 1899 there appeared in the Black Hills Mining Review† a short note announcing the discovery of certain deposits of wolframite in the vicinity of Lead City and Yellow creek, Lawrence co., South Dakota.

Jan 1, 1902

By L. A. Adorjan

The tensile strength of agglomerate models due to capillary forces has been determined by computation of the exact surface profiles. Graphs showing tensile strength as a function of moisture content and contact angle me given for spheres in cubic arrangement. Another model of cones attached to cube faces, in cubic packing, provides a better representation of angular particle agglomerates. An algebraic formula approximating tensile strength as dependent on surface tension, particle size, moisture content, contact and cone angles was developed. The phenomenon of "capillary evaporation" due to high negative capillary pressures is explained and its influence on tensile strength of agglomerates is evaluated.

Jan 1, 1977

By W. E. Crandall

The No. 4 shaft and hoist at Hecla Mining Co.'s Star mine have been in operation for seven months, and as development of new mining areas proceeds in the lower portions of the mine, the system is being depended upon more extensively for personnel and material handling requirements. The hoist plant is handling full payloads, at rated speeds, over a vertical distance of 5650 ft. One of the special features of this hoist is its precision braking control under all hoisting conditions. Tests indicate that emergency stops can be made with safe deceleration rates and minimum rope and conveyance oscillation.

Jan 1, 1971

By J. H. Johns, G. R. Stephan

The Climax mine has a history of dealing with ground control problems caused by major stress concentrations in the orebody. These stress concentrations, called weight, can arise in a variety of ways. The general effects of depth, rock type, and mining method give rise to weight problems, but local geologic features and daily cave line management can have even greater effects. Over the years a number of techniques have been developed for identifying weight problems in advance and for cow with them. These techniques all help us to amid interrupting the pace of cave advance and minimize the loss of production.

Jan 1, 1984

By John Edgar, Eugene P. Pfleider

Breakage of rock in mining operations as a part of the overall comminution process is examined. Examples of blasting practice are examined, and the energy expended is related to the comminution work accomplished. Costs for the comminution effected are examined, and an attempt is made to evaluate overall mining practice to determine the range of incremental costs for breaking the ore to a finer size in the mining step.

Jan 1, 1973

By B. S. Butler

It is suggested that at high temperatures both sulfur and iron combine with oxygen. Iron may precipitate at the high temperatures as the oxides of iron, and sulfur also in combination with oxygen as the low solubility sulfates of barium, strontium, calcium, and potassium (alunite). At lower temperature the precipitation results from change of sulfate sulfur to sulfide sulfur, and the iron precipitates as the sulfide.

Oct 1, 1956

By J. Federico Price, Joseph E. Aparicio

This paper describes the production of a specific iron oxide pellet that has given very good and consistent results as feedstock for HYC-Process Direct Reduction Plants. The sponge iron originated from these pellets has been used for the economic production of almost 15 Mt of low carbon steel via electric arc furnace meltshops. An overview of mining, beneficiation, pelletizing, direct reduction and steelmaking for this case is given with emphasis on the charactertitics of the self-fluxing oxide pellets.

Jan 1, 1982

By E. C. Reed

Ninety wells were completed in Nebraska during 1941, of which 42 were producers. One of them was the discovery well of a new field. All of the production to date is in Richardson County. At the close of the year 14 wells were drilling and three more were shut down for orders, hoping for future development of production. Most of the drilling activity was in Richardson County, which had 68 operations; 10 wells were drilled in Nemaha County, 5 drilled or drilling in Gage County, 3 each in Otoe and Furnas Counties, 2 each in Cass, Harlan, Johnson and Sarpy Counties, and 10 wells were completed or drilling over the remainder of the state. The most important development of the year was the discovery in October of the Barada field, sec. 36, T. 3 N., R. 16 E.,

Jan 1, 1942

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 P. K. Koh, L. S. Birks, J. M. Siomkajlo

Direct identification in situ of x and a phase precipitates in stainless steel is possible with the electron probe microanalyzer. Although particles in the 1 p size range are too small to yield absolute percent composition, the relative % Crfi Mo ratio can be used to distinguish the two phases with better than 95 pct confidence. Wet chemical analysis of extracted residues gives Cr/Mo ratios in good agreement with electron probe results extrapolated to the 4 to 5 p size range. WHEN stainless steels are subjected to extended heating in the temperature region around 1600°F, precipitation of the brittle 0 or x phases may occur and impair the properties of the material. Identi-

Jan 1, 1961

By Oliver Bowles

WHEN a new type of equipment revolutionizes methods of quarrying one kind of stone, producers of other kinds focus their attention on its potentialities in their particular fields. The purpose of this paper is to discuss the accomplishments of the wire saw in slate, to show its more limited attainments in other kinds of stone, and to point out the possibili-ties of much wider application. A wire saw consists of a 3/16-in. or 1/4-in. three-strand wire cable that runs as a belt and cuts the rock by abrasion. (Fig. 1.) The teeth of the saw are sand grains carried in the grooves between the strands.

Jan 1, 1936

By F. Hulsmeir

The increase in drilling activities in Venezuela noted during the latter half of 1932 continued, and 132 wells were completed in 1933 as compared to only 60 completed during 1932. Notwithstanding these new wells, 114 of which were producers, and also the appreciable increase in artificial lifting installations during the year, Venezuelan production was maintained at only a slightly higher level than in 1932, amounting to 120,356,000 bbl. in 1933 as compared to 118,167,000 bbl. in 1932. However, at the end of the year the daily average production of 358,-860 bbl. was 16 per cent higher than that at the end of 1932. Exports from Venezuela recorded an increase of approximately 4 per cent, totaling

Jan 1, 1934

By Roger L. Winter, Borje O. Saxberg

Some form of wage incentives has been used traditionally in the mining industry to determine miners' pay. However, very little is actually known about the administration of such wage incentive plans in mining. As far as the authors know this is the first time a general examination of wage incentive systems as applied to underground mining has been undertaken.* This article reports the results of an investigation pertaining to the administration of wage incentive programs for miners who drill, blast, and load- mainly in underground metallic mining operations. This investigation was conducted to obtain management's views and attitudes towards wage incentives; therefore, the results do not necessarily represent accurately the thoughts of the miners themselves nor those of any organized union of miners.

Jan 10, 1960