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PRESIDENTS DAVID THOMAS 1871 R W RAYMOND 1872-1874 A L HOLLEY1875 ABRAM S HEWITT 1876 T STERRY HUNT 1877 ECKLEY B COXE 1878 - 1879 WILLIAM P SHINN 1880 WILLIAM METCALF 1881 RICHARD P ROTHWELL 1882 ROBERY W HUNT 1883 JAMES C, BAYLES 1884-1885 ROBERT H RICHARDS 1886 THOMAS EGLESTON 1887

Jan 1, 1923

By R. P. Carreker

GERMANIUM is a member of that group of ele-nents—carbon, silicon, germanium, and tin-— that are currently of particular interest because of their interesting electrical properties. Near room temperature these materials of diamond cubic crystal structure are characteristically brittle. However, there have been several recent reports that germanium is not brittle at elevated temperatures These observations may be summarized as follows: 1—Germanium single crystals were observed to creep in bending under a maximum fiber stress of 6 kg per mm&apos; (8500 psi) at 500°C and above.&apos; The creep curves were sigmoidal, with an induction period that decreased with increasing temperature. 2—Germanium crystal bars have been bent 90" about radii ten times the bar thickness at 550°C.&apos; 3—-Audible clicks were heard when l/4 in. thick crystals were bent drastically at 450" to 500°C. No microstructural evidence of mechanical twinning was observed 4—Slip lines have been observed in tensile specimens deformed at 600°C, and are coincident with (111) planes, the close-packed planes of the diamond cubic structure.] The slip direction has not been established. 5—A germanium crystal has been compressed approximately 20 pct along a <110> axis at 700°C." The results reported subsequently were obtained in exploratory experiments intended to indicate some aspects of the behavior of germanium single crystals when tested in simple tension. Specimen Preparation A single crystal bar of n-type germanium was used. It was of purity corresponding to a resistance range of 2 to 20 ohm-cm. Tensile specimens were prepared by cutting small rectangular bars

Jan 1, 1957

By Thomas Carnahan

THE mining property of the Utah Copper Co. is situated in the West Mountain mining district, Salt Lake County, Utah, in the Oquirrh Range of mountains. GEOLOGY In a general way the rock formation of the district consists of a series of beds of quartzite and limestone intruded by a body of monzonite porphyry roughly elliptical in shape, with an east-west axis over a mile in length and a north-south axis of about 3,000 ft. This porphyry intrusion, accompanied by strong mineralizing action and fracturing, resulted in the formation of orebodies in the adjacent sedimentary rocks, and was itself sufficiently mineralized to make it one vast orebody. The Utah Copper Co.&apos;s mining property comprises within its boundaries practically the entire outcrop of the monzonite mass, of a commercial grade. GENESIS OF PORPHYRY ORE Following an intricate system of fracturing, mineral solutions circulated freely through the porphyry, depositing small quantities of copper and iron, and resulting in a considerable silicification of the monzonite. The quantity of copper originally deposited was undoubtedly too small to have ever given the porphyry a commercial value, had not secondary enrichment, due to the leaching of the copper from the surface of the mass and re-deposition in the sulphide zone, been active over a long period of years. A large portion of the leached material has probably been .removed by erosion, but there still remains a blanket of leached and oxidized porphyry of varying thickness covering the sulphide ore, known as capping. Over certain sections of the orebody, this capping contains commercial quantities of copper carbonates, but most of it contains little or no copper.

Jan 1, 1916

By W. M. Lehrer

RECENT development of high-temperature brazing alloys has required information regarding the eutec-tic temperature and composition of the Pd-rich section of the Pd-B system.. Literature on this subject was found to be scanty with no complete system yet determined. Buddery and welch1 report an inter-metallic compound occurring in the Pd-B system at 6.33 wt pct B (PdsBz). Another source, Sieverts and Bruning,2 indicates that after annealing at 700°C, a 1.6 and a 2.0 wt pct B alloy were two phase whereas a 0.75 pct B alloy was single phase. Recent work3 using a hot-stage microscope has proposed a eutectic temperature of 743OC. This method utilized the observation of the onset of incipient melting at grain boundaries. The eutectic composition, however, was not determined. METHODS AND PR0CEDURES Five alloys were prepared by triple inert arc-melting high-purity palladium (95.98 pct) with additions of 2 to 6 pct purified amorphous boron. The alloys were crushed within a hardened steel mortar with a steel pestle. The 2 pct alloy, however, was too tough to be crushed in the above manner so was crushed by successive reductions through a rolling mill. Approximately 17 to 18 g of the crushed alloy was used in the thermal analysis. The alloys were melted in pure quartz crucibles. The thermocouple protection tubes were also of quartz and fused along the inside wall of crucibles to prevent floating of the thermocouple. This was an expediency as centering of the thermocouple in the melt would have been preferable. Melting was done in a tube furnace with a slow flow of tank helium maintained as a protective atmosphere. Heating and cooling rates were maintained at 3.5OC per min through the critical temperature ranges by means of a synchronous motor hook-up to a furnace controller. All specimens were heated to 100°C over the indicated liquidus on heating prior to reversing to the cooling cycle. Specimens emerged from the furnace with mirrorlike brightness attesting to the protective quality of the helium atmosphere. Thermal arrests were detected by the differential thermocouple technique using chrome l-alumel couples and nickel as the reference specimen. Arrests were recorded on a Leeds-Northrup automatic X-Y recorder. The specimen temperature and temperature difference were read to + 7.5OC and ± 1.5OC, respectively. These readings were well within the sensitivity of the instrument amplifier. Chromel-alumel couples were used in lieu of Pt-Rh as very few arrests were contemplated in excess of 1200" to 1300°C, the approach of instability. No standardization was performed on these thermocouples subsequent to their use. RESULTS The thermal arrest temperatures obtained are plotted in Fig. 1 as a function of wt pct B. The composition function was obtained by chemical analysis of portions of the specimens after the thermal analysis was completed. The 2 to 6 pct nominal alloys were found to have 1.80, 2.35, 3.65, 4.18 and 5.90

Jan 1, 1960

By AIME

ALTHOUGH Thomas Savier Washburn, known always to his friends and associates as "Tom," entered this world in Minneapolis, the Flour Capital of America, and the tradition of flour milling was associated with his family name, he decided early to turn his back on such dusty pursuits and to court the Goddess of Fortune in the more romantic fields of mining and the metallurgy of iron and steel. Born in March 1901, his early education was gained successively in the Minneapolis public schools and the Blake School until 1918, and then in Phillips Andover Academy until 1920.

Jan 1, 1947

By AIME AIME

AN outstanding session of the Annual February Meeting was one held under the joint auspices of several groups on Tuesday afternoon, Feb. 22, as a symposium on the question of preserving peace in the postwar era through the control of the supply of sundry minerals vital to the Axis nations. D. H. McLaughlin and R. C. Allen were associate chairmen. And C.K. Leith led the discussion.

Jan 1, 1944

By A. T. Corey, J. H. Henderson, M. R. J. Wyllie, C. H. Rathjens

The results of three-phase relative permeability tests on nine water-wet consolidated Berea sandstone samples are presented as composite ternary diagranls showing isoperms of oil, water and gas. Capillary pressure control was exercised over the flow of gas and oil in the presence of water. The water saturations ranged from 17 to 71 per cent pore volume. A method of calculating both the oil and water permeabilities of a three-phase system from the easily measured gas relative permeability is presented. EXPERIMENTAL PROCEDURE AND RESULTS A renewed interest has been shown in three-phase relative permeability as a result of recent developments involving underground combustion processes, steam injection, and other multiphase displacement processes. The experiments and results described here involved simultaneous flow of oil and gas in consolidated Berea sand with brine present as the wetting phase. Gas and oil relative permeabilities were measured on nine cores with CaC12 brine present as the wetting phase in saturations ranging from 17 to 71 per cent. The average residual liquid saturation of the cores was approximately 20 per cent. In order to make certain that brine was the wetting phase, the test cores were saturated with brine before contact with hydrocarbons. As an added precaution to avoid having oil displace brine from the wetting position as a result of changing wettability, each core was only used twice, i.e., first with a fixed percentage of brine and then for a gas-oil permeability determination with no brine present. The results, therefore, are presented as composite ternary diagrams representing the flow tests on nine individual cores having very similar properties. All tests were made using a modification of the capillary pressure techniquc described elsewhere. The effective oil permeability was measured before gas was introduced using a very small pressure gradient (a few centimeters of oil). This determination was made without selectively wet barriers in contact with the core. The cores were then placed between capillary barriers and gas-oil relative permeability curves obtained. The capillary barriers had been made water repellent with a silicone treatment. In determining gas-oil-water relative permeability in this fashion, control was exercised over the capillary pressure existing between the gas and oil. No control was exercised over the pressure difference existing between the oil and water. Athough an equal pressure gradient was applied to the gas and the oil phases, this pressure gradient does not exist in the water phase. Since the pressure gradient across the core was always much less than the displacement pressure of the fully saturated core, the pressure gradient can have caused only a very slight distortion of the oil-water interfaces. This slight distortion of the oil-water interfaces had a negligible effect on the validity of the oil permeabilities measured. The oil permeability, measured in the presence of water but with no gas present, was in every case equal. within experimental error, to the gas permeability of the gas-oil system when the oil saturation was the same as that of the water. Gas and oil relative permeabilities were plotted as a function of total liquid saturation. It was found that the gas relative permeability curves obtained on cores with brine present were identical with those obtained on the same cores with no brine present. The denominator for calculating oil relative permeabilities was the permeability found by extrapolation to infinite mean pressure (A la Klinken-berg). Fig. 1 illustrates gas-oil relative permeability results obtained on a typical core. The solid permeability curves represent the experimental data. The dashed oil relative permeability curve was calculated using the relationship;

Jan 1, 1957

Jan 1, 1890

Jan 1, 1932

COAL DIVISION Established as a Division September 20, 1929 A. Lee Barrett, Chairman Ralph E. Kirk, Chairman-elect David R. Mitchell, Secretary-Treasurer Professor of Mining The Pennsylvania State College State College, Pa.

Jan 1, 1952

Jan 1, 1946

By S. C. Hollister

An evaluation of the function of the engineer, so that means whereby education can best serve his needs can be adopted.

Jan 2, 1950

Jan 1, 1970

[Admissions: Aurel E. Smith, Chairman Edmond F. Egan Lawrence S. Fennell John S. Fuller Howard J. Ritts, Jr. Gene E. Roark Kenneth W. Robbins Ben M. Gottlieb Advertising: Bernard F. Klein, Chairman Henry N. Lyle R. E. Howard H. M. Krause, Jr. Mrs. Evelyn R. Robertson]

Jan 1, 1961

STANDING COMMITTEES. Executive. CHARLES F. RAND, Chairman. JAMES F. KEMP, JOSEPH W. RICHARDS, ALBERT R. LEDOUX, BENJAMIN B. THAYER. Membership.. BENJAMIN B. THAYER, Chairman. WALTER R. INGALLS, JOHN H. JANEWAY, JR., JOHN D. IRVING, HERMAN A. PROSSER. Finance. EDWARD L. YOUNG,Chairman. KARL EILERS, JAMES GAYLEY. Library. JAMES F. KEMP, Chairman. JOHN HAYS HAMMOND,3 E. GIBBON SPILSBURY,2 ALEX. C. HUMPHREYS,4 BRADLEY STOUGHTON.

Jan 7, 1913

[Instead of presenting his paper, as printed, Mr. Rice gave a brief illustrated lecture on the subject, the illustrations being largely maps of the coal fields in several parts of Europe, and graphic diagrams illustrating the production and consumption of coal throughout the world.

Jan 4, 1918

By AIME AIME

Photo

Jan 1, 1940

By T. C. Sandford

Thermal conductivity measurements of intact rock specimens do not reflect the effects of natural rock discontinuities, and large scale insitu tests are location specific and costly. To allow extrapolation of laboratory measurements to rock masses with discontinuities, the effects of discontinuities on rock thermal conductivity were measured using divided-bar techniques. The introduced discontinuities lowered the thermal conductivity in all cases, and conductivity decreased systematically with increasing roughness of the discontinuity. Conductivity increased with increasing pressure on the discontinuity.

Jan 1, 1984

By Charles A. Schffer

Several months ago, some specimens of the minerals occurring at the Etta tin mine, Dakota, were received at the laboratory of the Cornell University. On examining the heavy brownish-black portion, which I presumed was the tin-stone, I was surprised to find only a faint indication of tin. Further investigation showed the mineral to be tantalite. On searching carefully all the fragments received, a considerable quantity of that mineral was found, and only a single streak of cassiterite, which was attached to a mass of spodumene. Another lot of specimens, from the same locality, consisted of

Jan 1, 1885

By Stephen R. Holsinger

During 1972, Asarco&apos;s Silver Bell Unit embarked upon a project to test a digital computer-controlled grinding circuit against the performance of its other five grinding lines. The planning, implementation, and subsequent outcome of that project has been previously reported in a paper by Pitts 1, et al. This paper will describe the solutions to major problems incurred during the implementation of this control strategy on the remaining five primary grinding lines. Changes made in operating philosophy and methods during the expansion will also be discussed.

Jan 12, 1978