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By William D. Southard, Joseph W. Schlitt, Bruce P. Ream, Lawrence J. Haug

The operation of Kennecott 's Bingham Canyon copper precipitation plant, one of the world's largest, is described. This description includes a brief historical review of precipitation at Bingham and the general layout and operation of the present cone cementation facility. Current practices are based on results of studies undertaken to define improvements needed in each unit operation. These improvements were required to meet changing plant conditions and were implemented primarily within the constraints of the existing facilities. Specific unit operations included were the cone precipitators, the cone discharge thickener, the cone effluent settling basins, and the plate and frame filter presses. As a result of these improvements, loss of precipitated copper decreased and the degree of precipitation increased, raising copper recovery by 9 t/d. At the same time, iron consumption was reduced by 22.5 t/d. Problems in drying the cement copper were also overcome so that a product containing 12-15% moisture could be consistently delivered for smelting.

Jan 1, 1980

By W. Joseph Schlitt, William D. Southard, Bruce P. Ream, Lawrence J. Haug

The operation of Kennecott's Bingham Canyon copper precipitation plant, one of the world's largest, is described. This description includes a brief historical review of precipitation at Bingham and the general layout and operation of the present cone cementation facility. Current practices are based on results of studies undertaken to define improvements needed in each unit operation. These improvements were required to meet changing plant conditions and were implemented primarily within the constraints of the existing facilities. Specific unit operations included were the cone precipitators, the cone discharge thickener, the cone effluent settling basins, and the plate and frame filter presses. As a result of these improvements, loss of precipitated copper decreased and the degree of precipitation increased, raising copper recovery by 9 t/d. At the same time, iron consumption was reduced by 22.5 t/d. Problems in drying the cement copper were also overcome so that a product containing 12 - 15% moisture could be consistently delivered for smelting.

Jan 6, 1979

By O. T. Berge

Development and production from open cut mines continued its vigorous growth trend during the year 1968. Material handling and transportation were again exposed to the use of larger equipment with shovels, trucks and front end loaders leading the way. Highlights of World Mining Activities Africa: The Anglo American Corp. opened a new high-grade copper mine in Zambia during the year. In Angola, the Companhia Minera do Lobita planned a 3 million ton iron ore production for 1968 from new mines which will ultimately produce 5 million tons per year. A feasibility study of Bethlehem Steel Co., for the development of large high- grade iron ore reserves in Gabon, was in final stages of completion this year and Pickands Mather and Co. continued its investigation of iron ore deposits along the Ivory Coast.

Jan 2, 1969

By R. Kossowsky

Structural changes in Be-Cu, Be-Ni. Be - Ag, and Be-Fc alloys pressurized in a solid medium were invesligated by resistivity measurements , X-ray diffrac lion in situ and metallogvaphic examination. Some limited tests in liquid medium were also conducted. Good correlation was oblained between diauges of slope of relative resistance us pressure and changes in diffraction pattern. Metallographic examination rez:ealed that the copper, silver, and nickel alloys lwiu heauily due to the applicalion of pressure at room temperature. Using polarized light technique {1012}, {1011}, and possible {1010} twinning planes were identified. At eleuated temperature twinning was moslly confined to the {1012} planes. Although twin-ning could be promoted by application of hydroslutic pvessure (liquid medium), it was strongly enhanced by the pvesence of a nonhydvostatic shear component due to pressurizalion in a solid medium. It was further obserced that a decrease in grain size inlnibiled twinnitzg activily. A great deal of effort has been expended in recent years to render beryllium useful for structural applications. Efforts were concentrated towards a possible phase change and to promoting other than basal deformation modes. Quenching experiments to obtain the high-temperature bcc phase have failed,' nor were alloying additions successful in improving ductility of the brittle hcp phase.2 Herman et a1.3 have reported a new {1011} twinning mode in a Be-4.4 wt pct Cu alloy oriented for a C axis compression sustaining loads to 440,000 psi. A new approach using high-pressure techniques was undertaken at Curtiss-Wright, Wright Aeronautical Division Laboratories. Marder4 reported a 25 pct decrease in relative resistance of commercially pure beryllium at 92 kbar. He proposed that this discontinuity corresponded to the bcc phase found at high temperature; however, X-ray diffraction in silu did not confirm a phase transition.5 contre6 has recently shown that the bcc transition in pure beryllium is lowered to 800°C at 80 kbar accompanied by a 50 pct increase in relative resistance. The purpose of this paper is to report on one phase of an investigation of the effects of high pressures and temperatures in beryllium alloys, namely, twinning behavior in Be-Ni, Be-Cu, Be-Fe, and Be-Ag alloys pressurized to nearly 100 kbar and temperatures up to 200°C. EXPERIMENTAL METHODS Material was obtained from Nuclear Metals, Inc., in the form of a 1.5-mm-diam wire extruded in stainless-steel cladding at 1600° F. Nominal composition of the alloys is listed in Table I, and the major impurities are are given in Table 11. Pressures to 100 kbar* were ob- tained using a National Bureau of Standards type 100/400 ton tetrahedral unit supplied by Barogenics, Inc. This type of apparatus contains a retaining sleeve with a conically tapered internal surface and four pressure-intensifying anvil assemblies with tungsten carbide tips. The 10-mm-long specimen fits into a pyro-

Jan 1, 1968

By Tomek Ulatowski

INTRODUCTION In 1974, Industrial Miners Mexico, S.A. (IMMSA), agent for the borrowers, was the largest privately-held mining, smelting, and refining company in Mexico (accounting for 32% of Mexico's nonferrous metal and coal production in 1974), the fourth largest company in terms of sales, and the second most profitable company in Mexico, excluding government wholly-owned and operated industries. The company was engaged in the mining, smelting and refining of coal, copper, fluorite, gold, lead, silver, zinc and related by-products for domestic consumption and export. A combination of favorable factors led IMMSA to propose an investment plan amounting to US$286 million for 1974 through 1978, of which US$150 million was to be financed. These factors included: Substantial profits in 1973 and 1974 Positive near-term outlook for metal prices Success of the reinvestment program in increasing productivity Substantial additions to proved reserves during 1973-1974 and Fiscal incentives provided by the Mexican government to stimulate investment in the mining industry. The primary purpose of the investment program was to construct a new electrolytic zinc refinery and to expand and modernize many of the company's existing mining and refining facilities. THE BORROWER Company History Compania Miners Mexico, S.A. was incorporated in the city of Monterrey in 1918 as a wholly-owned subsidery of ASARCO Inc. (formerly American Smelting and Refining Company, New York) for the purpose of mining and processing non-ferrous metals and related products. In compliance with the Government's Mexicanization program, ASARCO Inc. divested itself of 51% of its equity in Compania Miners Asarco, S.A. on June 30, 1965. Subsequently, ownership in the divested share was apportioned as follows: 15% ownership in Compania Miners Asarco, S.A. to a group of private investors, and 36% in trust for subsequent public sale. The company's name was changed to Asarco Mexicana, S.A. in 1965. Mexican ownership in Asarco Mexicans, S.A. was increased to 51% in 1967, following the purchase of the 36% share ownership held in trust, and then to 66% in 1974 when ASARCO Inc. divested itself of an additional 15% of its holdings in Asarco Mexicans, S.A. Following its 1974 divestiture of 15% of Asarco Mexicans, S.A., ASARCO Inc's ownership in Asarco Mexicana, S.A. was reduced to 34%. In 1974, the company changed its name for the second time to Industrial Miners Mexico, S.A. (IMMSA). Fiscal Agreement IMMSA entered into a fiscal agreement with the Mexican government in 1969. The agreement, which was renewed in 1974, provided for 100% of the production and export tax corresponding to the federal government with a minimum of 50% of the amount refunded to be reinvested in fixed assets. Further, the agreement permitted the company to

Jan 1, 1985

G. A. Moore—The tin-fusion method has been a very favorable possibility for many years. The authors apparently have settled the question that delayed the method for a long time by showing that no hydrogen is absorbed in the tin. This, of course, is very important. I want to make a few remarks concerning the absolute accuracy of analysis, which must be the final basis for deciding among the various methods. From the figures in the paper, there seems to be some re-maining slight discrepancy on the actual amount of hydrogen present in various samples which may be presumed essentially identical. (This is of the order of the precision of individual analyses but appears in averaged results.) From the analyst's viewpoint, the tally of hydrogen content can be regarded as occurring in three portions. First is a large portion which comes off easily and automatically during sample storage and later on heating in the apparatus. This is fairly easily analyzed. Second is an item which may be either positive or negative in the tally sheet. In warm or hot evolution, this is a portion which, in practice, can never be re-

Jan 1, 1951

By W. R. Clark, W. W. Cotter

Jan 1, 1946

By W. W. Cotter, W. R. Clark

Jan 1, 1946

By M. C. Flemings, F. R. Mollard

Two-phase Pb-Sn alloys, ranging in compositiotz from 12 to 26 at. pct Pb, were unidirectionally solidified in a convection-fvee system, with thermal gradients in the liquid of up to 480°C per cm. Plane front solidification Loas achieved in all alloys at sufficiently steep gradient and slow growth rate. Conditions causing breakdown of the interface to a cellular or dendritic structure were roughly as predicted by a sinlple constitutional supercooling criterion. Structures of alloys of near-eutectic composition, solidified with plane front, exhibited a lamellar structure; the alloys furthest from the eutectic exhibited a rod-like morphology. Assumptions used in a previous paper for calculations of solute redistribution in two-phase plane front growth are shown to be reasonable for Pb-Sn alloys. Results of calculations are in good agveement with experiment. These show that variations in growth rate during solidification of the composite produce marked changes in average composition of the solid. IN a previous paper, Part I,' conditions necessary for plane front solidification of two-phase alloys were discussed and calculations given on solute redistribution in this type of solidification. This paper, Part 11, describes experiments on Pb-Sn alloys, designed to check the assumptions of the analyses presented, and to demonstrate their applicability to a given alloy system (Pb-Sn). APPARATUS AND PROCEDURE General. A vertical crystal growing unit was built for the study as described below, and "normal solidification" employed throughout (i.e., the ingot was completely melted except for a portion near the bottom end and then solidification initiated). The furnace was designed to permit achieving very low interface velocities, and steep gradients, in essential absence of convection; it is sketched in Figs. 1 and 2. Simple heat flow considerations indicated choice of a small-diameter specimen (ingot) to achieve high thermal gradients; ingot size chosen was 0.3 cm in diam. The ingots were held inside silica tubes 0.06 cm wall thickness. The requirement for an essentially convection-free system was met by use of the vertical furnace with the heat source over the heat sink, as well as by use of the small diameter ingots. In addition, by selection of tin-rich Pb-Sn alloys, the diffusion boundary layer (lead-rich) was denser than the bulk liquid and would not cause convection. The only apparent driving force for convection in this system was the small transverse temperature gradient resulting from heat flow into the samples from the furnace. Such convection must have been small, however, since 1) no temperature fluctuations in the melt were noted in the recordings, which would have indicated turbulent convection, and 2) experimental results obtained and described below could not have been achieved in presence of significant convection. Ingot Preparation. Pb-Sn alloys ranging from 12 to 26 at. pct Pb were prepared from high-purity lead and tin (99.9999 pct pure metal). Each alloy was prepared by first melting the pure metals in the proper ratio in air, in a Pyrex container. The melt was then stirred thoroughly with a graphite rod and cast into a preheated graphite mold. Ingots were then prepared from these castings for use in the actual experiments; each ingot consisted of a rod of alloy, 15 cm long in a 25-cm-long transparent fused-silica tube, 0.3 cm ID and 0.06 cm wall thickness. One chromel-alumel thermocouple, made with 0.004-in.-diam wire and protected by a two-hole alumina tube, was inserted into each ingot. The 1.5 cm of the thermocouple nearest the bead were protruding from the alumina tube and were coated with a very thin layer of boron nitride paste which provided electrical insulation while allowing good heat conduction. The electrically welded junction size was about that of each wire and the cross section of the two wires represented about 0.3 pct of the sample cross section. Including the coating, the thermocouple cross section still represented less than 0.5 pct of the ingot cross

Jan 1, 1968

By P. Bandopadhyay, T. C. Rao

Geologically the Indian coals belong to Gondwana formations. Being of drift origin, these coals contain high percentage of mineral matter distributed in finely disseminated form. Indian coal-preparation plants process prime coking and medium coking coals for use in steel plants. Limited resources of good quality coking coals (Table 1) could not keep pace with the rapid developments of the iron and steel industry in India. This resulted in the introduction of coal-preparation technology and the establishment of washeries in India in the last 30 years or so. The first four washeries were set up during the early fifties at West-Bokaro, Jamadoba, Lodna and Kargali. Next came the first non-coking coal washery at Nowrozabad set up by the Associated Cement Company. In 1961, following the recommendation of Central Coal Washeries Committee (1953-54), Hindustan Steel Ltd. had set up five central washeries at appropriate locations, viz Durgapur, Dugda (2 washeries), Patherdih and Bhojudih, so that the raw coal feed having similar washability characteristics can conveniently come from a number of collieries to a particular washery. Subsequently, to meet the increasing demand of metallurgical coal by steel plants, two more central washeries (at Durgapur and Chasnala) and three pit-head washeries (at Kathara, Swang and Gidi) were installed by 1970. The prime objective of washing Indian coking coal is essentially to reduce the ash content. All the washeries in India, taken together have an installed capacity of about 26 million tons of raw coal input per annum. Details of these washeries in respect of their annual capacity, main washing systems adopted and the nature and size of the products are given in Table 2. It can be observed from this table that (1) bulk of the coal is processed in units like jigs HM baths and HM cyclones; (2) only two of the washeries have cleaning circuits for treatment of fines.

Jan 1, 1980

ALEXANDER BRYDEN Alexander Bryden, clean of engineers in the anthracite mining field, and a member of the pioneer Pittston family, was claimed by death Wednesday, September 26, 1917. The announcement was not a surprise, as he had been in a critical condition for several days. Mr. Bryden had been in failing health for a year past, but his indomitable will kept him at his accustomed duties until quite recently. Two weeks before his death he attended the regular weekly meeting of the Board of Directors of the Miners' Savings Bank in Pittston, Pa. At that time he apparently felt that his end was fast approaching, as he bade farewell to his associates on the bank board. Until a few days before the end, he continued to give attention to business matters at his home, in preparation for the end, which he met unflinchingly. In the passing of Mr. Bryden, northeastern Pennsylvania loses one of the best-known mining engineers, and the community, a man who, throughout his long life, was actively interested in its social welfare and business prosperity. He was for many years prominent in the management of the mining operations of the Pennsylvania Coal Co., and at the time of his death held the position of consulting engineer of the Pennsylvania and Hillside Coal. Companies.

Jan 12, 1917

By S. F. Shaw

Tars paper is a review of the principal details of cyanide practice in several of the modern plants in America, mainly during the year 1908. Two of the mills, the Goldfield Consolidated and the Vets, Colorado, are not yet prepared to give data, the former having started about Jan. 1, 1909, and the latter not yet being completed. These two mills embody most of the latest methods and are therefore described as far as possible. I. CRUSHING. The principal methods of crushing ores for treatment by the cyanide process are with gyratory and jaw-crushers, stamps, Bryan and Huntington mills, and tube-mills. The first stage is usually done by gyratory or jaw-crushers, in a few cases sup-\

Jul 1, 1909

By executive order of the President, dated June 25, 1918, the investigation of matters relating to gas warfare, which had been initiated by the Director of the U. S. Bureau of Mines early in 1917, and had been continuously maintained and improved since, that time, was transferred to the recently created Division of Gas Warfare of the War Department. On the occasion of this transfer, both the President and the Secretary of War took occasion to speak most highly of the efficient service that had been rendered by the Bureau of Mines. It gives us great pleasure to reproduce here a letter from the President and from the Secretary of War, bearing on this subject and also to append a brief review of the work of the Bureau of Mines, prepared by its Director, Mr. Van H. Manning. The White House, Washington. June 26, 1918. MY DEAR MR. MANNING: I have had before me for some days the-question presented by the Secretary of War involving the transfer of the chemical section established by you at the American University from the Bureau of Mines to the newly organized Division-of Gas Warfare in which the War Department is now concentrating all the various facilities for offensive and defensive gas operations. I am satisfied that a more efficient organization can he effected by having these various activities under one direction and control, and my hesitation about acting in the matter has grown only out of a reluctance to take away from the Bureau of Mines a piece of work which thus far it has so effectively performed. The Secretary of War has assured me of his own recognition of the splendid work you have been able to do, and I am taking the liberty of enclosing a letter which I have received from him, in order that you may-see how fully the War Department recognizes the value of the services. I am to-day signing the order directing the transfer. I want, however, to express to you my own-appreciation of the fine and helpful piece of work which you-have-done, and to. say that this sort of team work by the bureaus outside of the direct war-making agency is one of the cheering and gratifying evidences of the way our official forces are inspired by the presence of a great national task. Cordially yours, Dr. Van. H. Manning, WOODROW WILSON. Chief, Bureau of Mines, Department of the Interior. War Department, Washington, June 25, 1918. MY DEAR MR. PRESIDENT: In connection with the proposed transfer of the chemical section at. American University from the Bureau of Mines to the newly constituted and consolidated Gas Service of the War Department, which you are considering, I am specially concerned to have you know how much the War Department appreciates the splendid services which have been rendered to the country and to the Army by the Department of the Interior, and especially by the Bureau of Mines under the direction of Dr. Manning. In the early days of preparation and organization, Dr. Manning's contact with scientific men throughout the country was indispensably valuable. He was able to summon from the universities and the technical laboratories of the country men of the highest quality and to inspire them with enthusiastic zeal in attacking new and difficult problems which had to be solved with the utmost speed. I do not see how the work could have been better done than he did it, and the present suggestion that the section now pass under the direction and control of the War Department grows out of the fact that the whole subject of gas warfare has assumed a fresh pressure and intensity, and the director of it must have the widest control so as to be able to use the resources at his command in the most effective way possible. The proposal does not involve the disruption of the fine group of scientific men Dr. Manning has brought together, but merely their transfer to General Sibert's direction. Respectfully yours, NEWTON D. BAKER.

Jan 9, 1918

By L. F. Reinartz

ANOTHER year has rolled by. We are twelve months further away from the start of the depression and. therefore that much nearer to recovery. The accumulated needs and wants 'of our lame, virile population are ready to burst their bonds as soon as confidence returns and credit is stabilized. The steel industry has been harassed by uncertainty of the Government's attitude toward organized labor's de¬mands, and irregularity in volume of production. Steel labor, if left to its own devices, would in most instances, march shoulder to shoulder with the management of steel plants in their effort to pull the industry nut of the ?red.? Cooperation between management and men has improved considerably during; the year.

Jan 1, 1935

By AIME AIME

A LUSTY baby of the Institute, the Coal Division, showed that it had acquired a full set of teeth and was capable of man's work at the Division meeting at Fairmont, W. Va., on March 26 and 27. At this second of a series of field meetings, the first of which was held in Pittsburgh last fall, the industry in the East was represented from top to bottom and good humor and enthusiasm were the predominant notes. West Virginians are always good hosts and this meeting would have proved the statement to any inclined to doubt it. The spacious auditorium of the Fairmont Hotel was arranged for the technical sessions, the hotel being headquarters for the meeting. About a hundred and twenty-five representatives were registered and in attendance when Thomas G. Fear, chairman, opened the morning session at 10 o'clock Mr. Fear first introduced Howard Eavenson, vice-chairman of the morning program, who, as chairman of the Coal Division, had labored long and cheerfully to make the meeting successful. Mr. Eavenson talked briefly on what the organization was doing, pointing out that these field meetings were designed to bring the members into closer touch with the parent Institute and give the younger engineers in the field a better opportunity to participate in the work the Institute is doing. He congratulated the various committees for their work in promoting the meeting.

Jan 1, 1931

By R. S. Archibald, L. S. Chabot

The Blueberry mine is about 10 miles west of Ishpeming, Marquette County, Michigan. The property consists of about 2000 acres in sees. 3, 4 and 5, T. 47, N.R. 28W. and secs. 32, 33 and 34, T. 48, N.R. 28W., and, excepting one intervening 80-acre tract, contains the iron formation for a length of about 21/4 miles. The property is traversed by State Highway M-28 and is served by three railways, the Chicago & Northwestern, the Duluth, South Shore & Atlantic, and the Lake Superior & Ishpeming. The Northwestern transports the ore to a dock at Escanaba; the other railways, to Marquette. Ore for Chicago goes via Escanaba and that for Lower Lake ports, as Detroit, Cleveland, and Buffalo, via Marquette. History The presence of iron formation in this property has been known for many years, and mining operations on a small scale have been carried on intermittently. The Dexter mine, on the SE.1/4 of the NW.1/4 of sec. 3, was worked from 1883 to 1897 and 118,000 tons of ore was mined. From 1907 to 1915 extensive exploration was carried on over the whole of sec. 3, including 79 diamond-drill holes with a total footage of 26,000 ft. The Chase mine, on the NE.1/4 of the NE.1/4 of sec. 3, was developed from this exploration work, but after about 200,000 tons had been mined the property was abandoned. From 1908 to 1910 exploration was carried on by another company on sec. 4, 47-28, including four drill holes with a total footage of about 5000 ft. Much of the drilling on sec. 3 and of the exploration work on sec. 4 are within the present developed area of the Blueberry mine. A general campaign of diamond-drill exploration was undertaken in 1924, and within a year a considerable amount of ore was developed. The Ford Motor Co. then took an option on the property and carried on check drilling and diamond-drill work until the spring of 1926, when enough ore had been developed to warrant the sinking of a shaft

Jan 1, 1937

By I. R. Kramer

The delay time for single crystals of iron, zinc, and pre-strained aluminum was measured under conditions of high-speed deformation. The delay time of aluminum was found to be affected by the orientation of the crystal. Under the dynamic conditions employed, tile calculated "activated volume" term appears to be very small for the three metals studied. IN a previous paper,1 it was shown that under dynamic testing conditions at 78° K, there was a delayed yield in single crystals of aluminum and copper which had been cold-worked prior to testing. The experimental results also indicated that the delay-time effect was not due to the interaction of dislocations with impurity atoms or vacancies, but rather to a dislocation-dislocation interaction since aluminum which has not been prestrained shows no delay-time phenomenon. In this paper, some data are reported on the effects of orientation on the delay time of aluminum single crystals; the delay time of zinc single crystals saturated with nitrogen and the delay time of iron single crystals also were measured. EXPERIMENTAL PROCEDURE Aluminum (99.997 pct) and zinc (99.999 pct) crystals, 1/2 in. in diam and 8 in. long were grown by the Bridgman technique. The iron single crystal was supplied by Dr. R. Maddin. The zinc crystals containing nitrogen were prepared by melting high-purity zinc in a graphite crucible and the nitrogen was introduced by additions of ammonium chloride. The liquid zinc was then drawn up into glass tubes of 1/2 in. diam and allowed to solidify. The rods were cooled to room temperature before the transfer to the mold for conversion into single crystals. The orientation of all specimens was determined by the Laue' back-reflection technique, Fig. 2 and Table I. To prepare for the delay-time measurements, the crystals were cut with a fine jewelers saw and the ends carefully machined. The specimens then were electrolytic ally polished to remove the cold-worked metal, mounted in a special fixture and hand-lapped. As a final step, the crystals were annealed in evacuated tubes. Specimens of aluminum crystals, Nos. 24 and 26, were compressed 0.5 and 2 pct, respectively, in the direction of the later impact. The zinc specimens were aged at 50°C for 15 min, In the case of iron, only two specimens could be obtained. To obtain sufficient data, it was necessary to resort to a reaging treatment. After each delay-time test, the specimens were aged at 65° C for 100 min. This treatment, according to Clark,2 is sufficient to restore the original delay time. It is believed that although the specimens were plastically deformed approximately 10-4 pct, after each test the delay-time values are reliable. The delay-time measurements were made in an apparatus similar to that described previously.' Single crystals approximately 1 in. long and having a diameter of 1/2 in. were placed in a pendulum which consisted of a bar 1/2 in. in diam and 8 ft long, designed with a crystal holder to accommodate the specimen at low temperatures. The crystal was held at a position 2 ft from the front part of the pendulum. This portion of the apparatus was supported on a fine molybdenum wire. A projectile bar of the same diameter and length comprised the other portion of the apparatus. This bar was supported on

Jan 1, 1962

By Davis M. Lapham

Ore bodies at Cornwall, Pennsylvania, have been mined since 1742 principally for iron from magnetite, but also for copper (in chalcopyrite), silver (in chalcopyrite), gold (in chalcopyrite), cobalt (in pyrite), sulfur, and crushed limestone aggregate. Metallization occurs as a limestone replacement above the essentially conformable, south dipping portion of a discordant saucershaped diabase sheet. Pre-Triassic and Triassic faulting have emplaced host Cambrian limestone and two Ordovician(?) hornfels units, now for the most part resting above diabase. Thermal metamorphism of carbonate-bearing country rocks largely to calc-silicates, is ubiquitous. Metasomatism, particularly of potassium, is unique to ore zones. Associated magnetite- actinolite mineralization replaces, in a preferential sequence, all earlier metamorphic and metasomatic minerals and rarely diabase chilled margin. Mineralogical (diopside, actinolite, mica, sulfides, oxides) and chemical (Fe, Cu, S, Co) zoning of the eastern ore body is focused down dip, near its western edge, along a major vertical fault through diabase. This zoning is spatially related to magnetite veins in diabase, to an ore body within diabase, and to a shear zone that probably extends through the sheet.

Jan 1, 1968

By P. A. Beck, L. J. Demer

As reported in a previous publication,' isothermal grain growth in high purity aluminum and in an aluminum alloy with 2 pct magnesium can be adequately described by means of the empirical relation: Here, D is the average gain size after an annealing period 1. The annealing period includes the time for complete recrystal-lization R, and the time for gain growth 1,. D, is the pain size as recrystallized, n is a parameter depending on the temperature and on the material. The effect of 2 pet magnesium in solid solution was to decrease D, and to increase R, A and n at a given temperature. The present work was undertaken in order to investigate the above listed-effects of magnesium in solid solution, as functions of the magnesium content. The work also includes the study of certain anomalous effects observed in the recrystal-lization and grain growth of the 2 pct magnesium alloy at 350°C. Experimental Procedure The method of producing the ingots used in this work was described in detail1 and need not be reproduced here. The materials used were high purity aluminum, furnished by the Aluminum Co. of America, of lot analysis shown in Table r and magnesium from a high purity distilled stock of magnesium crystals. Table i—Lot Analysis of High Purity Aluminum Per CeNt Si.................................... 0.00~ Fe.................................... 0.002 Cu................................... 0.002 Mg................................... 0.003 Mn................................... o. oox Ingots were prepared for a series of binary aluminum-magnesium alloys of increasing alloy content. The numbers used to designate these ingots and their magnesium contents by chemical analysis are given in Table 2. Table 2—Ingot Numbers and Magnesium Contents Ingot Number Pct oa Magnesium aI 2.05 22 1.80 24 0.12 26 0 02s The analyses showed no difference in composition between the top and the bottom of the ingots. Spectrographic analysis of the ingots for elements other than magnesium showed, within the limits of accuracy of the method, no increase in impurities over the amounts given in the lot analysis for the high purity aluminum in Table I. Careful microscopic study of ingot 21 in the as-cast condition, at magnifications up to I 500X, revealed a cer-

Jan 1, 1949

By Thomas T., Read

TWO American students entered the Ecole des Mines in 1856, Joseph Lesley of Philadelphia and Thomas Egleston of New York. Lesley remained there only one year, but Egleston completed the whole 'curriculum and received, in 1860, the certificate given to foreign students .in lieu of the official appointment and degree. awarded French students. Returning home he received, in 1861, an appointment by Secretary Henry of the Smithsonian Institution to sort, label, and arrange the collections of mineralogical and geological specimens which had been brought to Washington by the various government exploring expeditions in the West. Thomas Egleston, born in New York City on Dec. 9, 1832, was the son of Thomas Jefferson Egleston, who came to New York from Massachusetts some time before 1829. The first American ancestor of the family had settled near Dorchester. in 1630. T. J. Egleston and Joseph Battell established an iron-merchandizing business* at 166 South St., New, York, which prospered exceedingly; so much so that when Thomas J. Egleston died, July 12, 1861, his estate had a book value of over $500,000. Since an older brother was expected eventually to take over this business, Thomas, who had a liking for science, went to Yale,, where he completed the regular four-year course in 1854, and then remained another year for advanced work in chemistry under Silliman. I One biographer says he went to Europe, . early in 1-856, on account of his health. It was the custom at that time for wealthy young men to make a tour of Europe after completing their academic education. Whatever the precise reason, he began scientific work at the Jardin des Plantes in Paris but soon trans* It still operating as Egleston Bros. Inc., though no direct descendants of its founder are now living.

Jan 1, 1941