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By Otto H. Henry

The purpose of this investigation was to determine the equilibrium diagram of the lithium-magnesium pair as a first step in studying the possible usefulness of these alloys as ultra-light structural materials. Review of the Literature The behavior of lithium towards magnesium was first investigated by Masing and Tammann.(1)† In order to prevent oxidation the alloys were made in iron tubes under an atmosphere of hydrogen; temperatures were measured with a glass-protected thermocouple. These investigators found that lithium and magnesium form two series of solid solutions separated by a miscibility gap between 85 and 95 per cent magnesium; that the alloys with 81 and 95 per cent magnesium showed a homogeneous structure under microscopic examination, while the alloy with 89 per cent magnesium contained two distinguishable crystallites; that the curve indicating the beginning of crystallization rises from the melting point of lithium to that of magnesium; and that no compounds of lithium and magnesium are formed. The equilibrium diagram was not plotted because no definite data were obtained for determining the solidus and the position of the miscibility gap in the solid state. The difficulties encountered in this investigation were: (1) that it was necessary to heat them as high as the melting point of magnesium in order to obtain homogeneous melts; at such temperatures the alloys attacked the glass protecting the thermocouple; and (2) that at temperatures above 400" C. the lithium united with the hydrogen to form lithium hydride, thus contaminating the alloys. By applying the same methods as those used in the lithium-magnesium system, Masing and Tammann determined the equilibrium diagram of the

Jan 1, 1934

By Allen L. Hatch

A survey of all phases of the world's lead and zinc production in 1968 from ore through to refined metal was conducted by sending questionnaires to individual companies ad the results of this survey are tabulated at the end of the paper. The paper goes on to review changes in the geographical distribution of the world's lead and zinc mine and metal production and in the trading patterns of raw materials, present and future utilization of metal production capacity, developments in metal smelting and refining processes and the growing importance of marketing, product development and research in the 1950's and 1960's.

Jan 1, 1970

By Cyril Stanley Smith, Earl W. Palmer

A STUDY of the precipitation-hardening of copper steels1 led the authors to investigate malleable iron containing copper, for the low-carbon ferritic matrix in malleable iron should lend itself admirably to precipitation-hardening. It was soon found that in addition to rendering malleable iron susceptible to improvement by precipitation-hardening treatments, copper has another potentially useful effect as an accelerator of graphitization. Brief mention of these effects was given in a general paper by Lorig and one of the present authors2; the present paper gives further details on the graphitization and precipitation-hardening effects only. After the completion of this work a paper by L. Lykkin3 appeared, confirming the authors' conclusions regarding graphitization. MATERIAL USED After some preliminary heats had been made in the laboratory to determine the effect of copper, several castings from commercial air-furnace heats were obtained, and data from these alone are given here. Part of the metal was poured directly and part was treated in the ladle with the desired amount of copper before pouring. Green-sand molds were used, each holding two tensile test pieces of the form adopted by the Malleable Iron Research Institute, or two bars for graphitization studies, 5/8 in. in diameter and 9 in. long, fed through two enlarged sections equidistant from the middle and ends of the bars. Risers of suitable size insured sound castings. Tensile tests were made

Jan 1, 1935

By G. S. Rice

The subject of dust explosions in coad mines first appears in the Transactions of this Institute following the first great mine disaster that happened in…

Jan 1, 1915

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Jan 1, 1938

By John Drew Ridge

For the early conservationists before the first decade of the twentieth century, conservation meant largely the planned preservation of water, forest, soil, and wildlife resources-renewable natural resources-through efficient use. Water was primarily thought of as a resource that must be kept available for humans to enjoy in a recreational sense and as a habitat for wild animals, birds, and fish. Little thought was given to conserving water for actual human or industrial needs. If industry entered the picture it was as an actual or potential polluter of water, which was the basic necessity for drinking and bathing and for outdoor recreation. Even the forests were only held worthy of conservation largely because they were areas in which wildlife could, or should, abound and in which human beings might find relief from the cares and problems of everyday life. Finally, the soil was to be preserved in its natural fertility through proper fertilization, cultivation, and crop rotation; in this the conservation program did enter the realm of the practical. For through soil conservation, the world was to be able to raise increasingly large crops of constantly improved organic foods which the steadily growing population of the earth was to need to survive and improve. Relatively little time, however, was spent on considering what profit the farmers of the world were to make from the scientific farming on which they were to embark. In short, the appeal of the early conservationist program was much the same as that of the entire era of Theodore Roosevelt of which it was a part; it was to the heart rather than to the mind; it was to emotion rather than to reason. Because of the way in which the problem was approached, conservation took on the character of a crusade rather than that of a practical plan for the betterment of man through economically sound methods of improving his environment and the uses he makes of it. Conservation had, then, all the advantages of a stirring appeal to the emotions, but it did not have the lasting results that would have been achieved by a program with a sound economic basis.

Jan 1, 1959

[United States PAGE Alabama 181 Alaska 181 Arizona 181 Arkansas 182 California 182 Colorado 185 Connecticut 186 Delaware 186 District of Columbia 187 Florida 187 Georgia 187 Idaho 187 Illinois 188 Indiana 189 Iowa 189 Kansas 189]

Jan 1, 1928

By Georg Masing

Jan 1, 1933

Jan 1, 1951

By J. W. Pugh

PREFERRED orientations in cold-rolled body-centered-cubic metals appear to have remarkable similarity. The as-cold-rolled textures in iron,1,2 silicon-iron,3 mild steel,4 molybdenum, vanadium,&apos; chromium,&apos; tantalum,&apos; tungsten,&apos; and a-zirconium-niobium alloys10 have been determined. These textures have, in some cases, been represented by congrUOUS pole figures and have all been described in one or both of two ways. They have frequently been reported as predominantly (100) <011> orientation

Jan 1, 1959

By J. A. Barr

Tennessee phosphates are commercially divided into three varieties: Brown, Blue, and White.

Jan 1, 1915

CONTENTS PAGE East Texas, except the Gulf Coast-H. Vance 3 Gulf Coast-L. P. Teas 8 Texas Panhandle-C. C. Rae 16 North Central Texas-H. F. Smiley 23 North Louisiana, South Arkansas and Mississippi-B. C. Craft 25 Oklahoma-C. H. Pishny, Raymond M. Carr and E. J. Dickinson 31 Kansas-E. A. Koester 35 Rocky Mountain District-C. D. Johnson 46 Illinois and Indiana-T. Wasson 49 Michigan-T. Wasson 52 Eastern States-P. D. Torrey and W. H. Young, Jr 58 West Texas and New Mexico-W. V. Vietti. Published as a Supplement.

Jan 1, 1933

By G. A. Hellstrand

IN 1915, H. A. Guess, Vice President of American Smelting & Refining Co., in charge of its Mining Department, learned that the Anglo-New-foundland Development Co., Ltd., a pulpwood and paper-mill enterprise, had found upon its large concession in Newfoundland, and had opened up by shaft to the third level and some drifting, a lenticular orebody indicat-ing about 100,000 tons, as an extremely fine-grained sulfide ore, averaging about 0.05 oz. Au, 4 oz. Ag, 1.5 per cent Cu, 10 per cent Pb, 18 per cent Zn; and that having sent parcels of this ore to Minerals Separation, Ltd., and various other metallurgical testing concerns without obtaining any success in commercial separations thereon, had discontinued work thereon and let the workings fill. Mr. Guess wrote to the general manager of that company and obtained a few hundred pounds of the typical ore, which he sent to his company&apos;s metallurgical testing laboratory at Flat River, Mo., outlining various flotation tests desired thereon, in an endeavor to obtain separation into a commercial lead concentrate and a zinc concentrate. But the art of flotation had not then progressed far enough to treat such ore, the galena and zinc blende being so fine grained that grinding to about 300 mesh was required to release the mineral particles in their gangue. Mr. Guess had flotation and other tests continued upon this ore from time to time with whatever new reagents and flotation devices were evolved as time went on, and finally, in 1925, he succeeded in effecting in his company&apos;s testing plant, then at Wallace, Idaho, separations into lead concentrates and zinc concentrates of satisfactory commercial grade. Mr. Guess then proceeded to unwater, examine and sample the property and made with the owners a partnership operating agreement upon the mine itself and a considerable area surrounding it, and in the early summer of 1926 began to prospect for additional orebodies, utilizing for such prospecting geophysical methods, under the direction of Hans Lundberg, methods which up to that time had been little used in mining in the western hemisphere.. This geophysical work found two large flat-lying orebodies of a type precisely similar to the smaller body of the original discovery. The larger orebody, some 3500 ft. west of the original

Jan 1, 1934

By A. W. H. Morris, E. A. Steigerwald

The jatzgue beizazriov oj Mietal matrix co))zpos~tes in tension -lensiom loading has been imestigated as a junction of Dolume fraclion veinfovcelnent using the model systems of a silver matrix reinforced with contlnuous or dzscontztinuous aligned tungsten jilamenls and continuous aligned steel filamenls. Appreciable impvocetnents in fatigue strength were obseved in all syslems inzvesLigated, the degree of sl renglhenng-increasing with increasing volume fraclion of reinforcement. The mode of fatigue failure was found to be a function of colutrre jp-actiotz and was also noted to be controlled by the relative fatigue and strength characlerislics of the matrix and reinforcemenl. THE advantages to be gained by suitably incorporating high-strength filaments or whiskers into metallic matrices are well-recognized.&apos; To date emphasis has been placed on the experimental determination of tensile strengths and elastic moduli of metal matrix composites measured parallel to unidirectionally aligned filaments. Several attempts have been made to relate experimentally measured tensile properties to theoretical values calculated from the properties of the components on the basis of the relatively simple "rule of mixtures" analysis. However, relatively few data have been reported in the literature on the fatigue behavior and mechanism of fatigue failure of metal matrix composites. In a study of fatigue crack propagation in aluminum plus steel wires and aluminum plus tungsten wires, Forsyth et a1.2 found that the incorporation of small numbers of filaments suitably dispersed were capable of substantially reducing the rate of fatigue crack propagation. For this purpose, the strength of the filaments appeared to be more important than the aspect ratio and the authors reported that parallel filaments were not the most favorable orientation for increased strength. In a basic study of the fiber reinforcement of metals, Williams and 0&apos;brien3 report preliminary results which indicate a considerable improvement in fatigue strength in reversed bending fatigue of a steel wire-reinforced aluminum alloy composite. In a study of the influence of interfacial bonding on fatigue behavior, Baker4 has also reported improved fatigue properties in stainless steel-reinforced aluminum composites. In contrast, Ham and place5 report that, although tensile properties are improved greatly by filament reinforcement, the reinforcement of copper with continuous, brittle tungsten wires up to 23 vol pct was comparatively ineffective against fatigue. The authors attribute the poor fatigue properties of the composite to fatigue hardening of the matrix at the tips of cracks which can build up stress concentrations sufficiently large to fracture proximate filaments. Baker and cratchley6 failed to find marked improvements in the reversed-bending fatigue properties of silica-reinforced aluminum. The study was complicated by the complex behavior in a composite during the compres-sive half-cycles imposed in this type of loading. This was manifested in the failure of the composites by de-lamination, a contributing factor being the presence of aluminum oxide at the matrix-filament interface. Prior to the general acceptance of filament-rein-

Jan 1, 1968

Jan 1, 1915

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Jan 1, 1938

By G. E. Goodspeed

THE Cornucopia gold quartz veins form a parallel vein system traversing metamorphic and granodioritic rocks. Field and petrographic evidence suggests that metasomatism has played an important role both in the emplacement of the granodiorite and in the formation of the veins. Structurally the veins appear to be related to the major tectonic features of the Wallowa Mountains and to be narrow shear zones rather than filled fissures. Petrographic studies indicate a complex history of formation starting from initial alteration along fractures or joints followed by recurrent fracturing and a quartz-forming stage, and closing with continued shearing and microbrecciation, which permitted the upward percolation of the later ore- forming solutions. The precipitation of ore minerals from these solutions formed ore shoots. Postmineral effects include the injection of Tertiary basaltic dikes, a slight amount of cross faulting, and some movement along the planes of the veins as well as oxidation.

Jan 1, 1939

By A. L. Hornbaker, S. D. Schwochow

Industrial minerals are becoming increasingly important in Colorado&apos;s mining industry, not only in production value but also in the variety available and in their potential development for both conventional and new uses. Fluorspar, building stone, fire clay, and pegmatite minerals have been historically important but are not now extensively mined. Aggregates (sand, gravel, and crushed stone), cement materials, metallurgical limestone, and common clays currently are the highest valued commodities. Those offering the greatest future potential include diamonds, nahcolite and dawsonite associated with oil shale, alunite, potash, zeolites, and rare earths.

Jan 1, 1982

By C. E. Birchenall, J. R. Stubbles

ThE equilibrium between lead, lead sulfide (PbS), and atmospheres of H2 and H2S has been determined previously by Jellinek and Deubel,&apos; and SudO.&apos; Blbem and Kroger3,4 used Jellinek&apos;s data to calculate the sulfur dissociation pressures of PbS crystals (of

Jan 1, 1960

Calendar of Events

Jan 11, 1961