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By Walter E. Heinrichs

Since World War II exploration geophysics has derived its scope from the following factors: first, the usual post-war interest in exploration to rebuild war-depleted reserves; second, the impetus supplied by the uranium prospecting boom; third, increased demand for natural resources due to the Korean War; fourth, the discovery of substantial metallic ore by geophysical means in Canada, the U. S., and other countries; and, finally, continuing discoveries of commercial oil by geophysical methods throughout the world. The past year's national business slump has severely curtailed mining exploration in general and correspondingly has brought about even greater reductions in applied geophysics in mining. Petroleum exploration, conceived and executed on a broader statistical basis than mining, has kept up its geophysical programs relatively well, although domestic work has been substantially reduced.

Jan 7, 1959

Jan 1, 1967

Jan 1, 1968

By J. F. K. Brown

ANTHRACITE?S satisfactory showing in 1942 was accomplished in the face of adverse conditions, such as the loss of man power to the active services and to other industries, and the difficulty and delay in obtaining the necessary materials and equipment required in mining operations. Although the in- creased output was stimulated by the war, and thus does not impress one as contributing to continuing improvement in the industry, nevertheless the year witnessed several efforts ant1 consideration of others that have the appearance of permanent progress.

Jan 1, 1943

Jan 1, 1967

By Valentine Garfias

THE various phases of the Mexican oil industry have received so much publicity that there is little to add to the discussion of present and future production, extent and importance of prospective fields, and status of petroleum legislation, to mention but a few of the angles of the Mexican oil problem. However, out of this wealth of information, which is generally of contradictory nature, the average petroleum man is at a loss to know something definite regarding the various questions involved so, keeping the foregoing in mind, it has been the writer's aim to record in a concise form the most reliable and up-to-date information regarding the salient features of the Mexican oil situation. PRESENT STATUS OF MEXICAN OIL INDUSTRY Production During 1921 The Mexican oil fields, during 1921, produced in round numbers 203,000,000 bbl. of which 176,000,000 bbl., or 86 per cent., were exported, the bulk of -these exports, or about 73.3 per cent., going to the United States. The Mexican exports were divided by grades as follows: Light crude, 47.0 per cent.; heavy crude, 22.0 per cent.; tops, 3.5 per cent.; fuel oil from light crude, 24.0 per cent. The balance, or 3 1/2 per cent., includes the bunker fuel shipments and the coastwise trade in Mexico, which is not classified as to grades. The figures show that, in importance, the light-oil fields from about 755 per cent. of the Mexican petroleum industry.

Jan 4, 1922

By G. Derge, Lo Ching Chang

The chemical and physical propertties of slag systems are of special interest to metallurgists, for nearly all metals are in contact with molten slags during the primary reduction from their ores and then during the subsequent refining and alloying processes that determine their ultimate use. These processes are carried out at high temperatures and involve such complex chemical systems that funda-mental scientific knowledge of the Properties and behavior of these slags is inadequate. Various hypotheses have been Proposed to explain known slag characteristics. The commonest of these regard the molten slag as constituted of compounds that are dissociated in varying degrees into their constituent oxides, as illustrated by Schenckl and the recent Papers of Chipman and co-authors. Another proposal is that these compounds dissociate by com-plete6 or partial ionization, the evidence for which has been reviewed by Martin and Derge.? whatever hypothesis is favored, the exact formulation of these compounds is incomplete. It is based on three principal types of information: 1. Studies of solidified 51% samples by X ray diffraction, petrography, and similar methods that can be used at room temperature. The correlation of this information with the high-temperature properties of the molten slag is uncertain. 2. Studies of slag-metal equilibria, which have the advantage of providing observations on the molten slag at high temperature. However, even these data present problems of interpretation because they require a complete knowledge of the metal phase. 3. Direct measurements of properties of molten slag at the temperature of greatest metallurgical interest. Viscosity, electrical conductivity, specific heats, and similar properties have been measured, but the data of this type are widely scattered and frequently difficult to interpret. Additional direct measurements of properties of molten slag that can be interpreted in terms of chemical behavior are required, and this paper shows that the standard physical-chemical measurement of reversible electrode potentials, which measure the activity of specific constituents, is a fruitful source of such information. The purpose of this investigation, therefore, was to find an electrode combination that would yield reversible electromotive force measurements when dipped into the molten slag to be studied. Slags of the systems cao-sio2 and cao-120,-SiO2 were chosen for study because graphite containers could be used and the data could be correlated with those for viscosity, conductivity, and other proper-

Jan 1, 1948

By G. Derge

The chemical and physical propertties of slag systems are of special interest to metallurgists, for nearly all metals are in contact with molten slags during the primary reduction from their ores and then during the subsequent refining and alloying processes that determine their ultimate use. These processes are carried out at high temperatures and involve such complex chemical systems that funda-mental scientific knowledge of the Properties and behavior of these slags is inadequate. Various hypotheses have been Proposed to explain known slag characteristics. The commonest of these regard the molten slag as constituted of compounds that are dissociated in varying degrees into their constituent oxides, as illustrated by Schenckl and the recent Papers of Chipman and co-authors. Another proposal is that these compounds dissociate by com-plete6 or partial ionization, the evidence for which has been reviewed by Martin and Derge.? whatever hypothesis is favored, the exact formulation of these compounds is incomplete. It is based on three principal types of information: 1. Studies of solidified 51% samples by X ray diffraction, petrography, and similar methods that can be used at room temperature. The correlation of this information with the high-temperature properties of the molten slag is uncertain. 2. Studies of slag-metal equilibria, which have the advantage of providing observations on the molten slag at high temperature. However, even these data present problems of interpretation because they require a complete knowledge of the metal phase. 3. Direct measurements of properties of molten slag at the temperature of greatest metallurgical interest. Viscosity, electrical conductivity, specific heats, and similar properties have been measured, but the data of this type are widely scattered and frequently difficult to interpret. Additional direct measurements of properties of molten slag that can be interpreted in terms of chemical behavior are required, and this paper shows that the standard physical-chemical measurement of reversible electrode potentials, which measure the activity of specific constituents, is a fruitful source of such information. The purpose of this investigation, therefore, was to find an electrode combination that would yield reversible electromotive force measurements when dipped into the molten slag to be studied. Slags of the systems cao-sio2 and cao-120,-SiO2 were chosen for study because graphite containers could be used and the data could be correlated with those for viscosity, conductivity, and other proper-

Jan 1, 1948

By B. E. Mix, L. M. Barker

THe present methods of unloading ore and coarse-crushing at the Magna plant of the Utah Copper Co. are the developments of the pas five years. Hand dumping and breaking have given way to the rotary car dump and large gyratory; and the bucket elevators and stationary screens have been replaced by conveyors and shaking screens. The coarse-crushing plant may be broadly divided into two units the primary crushing and the secondary crushing, or primary roll, unit The former was erected in 1923; with the exception of the excavation the construction was carried on by forces of the company. Excavation was started in the middle of March, the first concrete was poured July 16, erection of the steel building started Oct. 30, and the unit was com pleted and operating Dec. 30. The unit has a capacity of over 24,001 tons of ore per day, and cost more than a million dollars. Remodeling of the primary-roll unit extended over a period of years preceding this some of the work having been done as early as 1918. Delivery of Ore from Mine, Yard Storage, and Handling Ori Cars to and from Primary Crushing Plant The ore is transported, in steel cars of 80 tons capacity, from the min' to the mill, where a reserve tonnage of loaded cars is maintained. Malle locomotives, handling trains of 45 cars, or approximately 3600 tons o ore per train, deliver the trains to a storage yard which contains thre tracks—a passing track and two storage tracks. All of this trackage i equipped with an overhead trolley system, so that electric locomotive can be used in yard switching. The storage tracks have a total length of 4500 ft. and provide storag space for 140 cars. The passing track, besides permitting switchin room for locomotives, is used for storage purposes between train arrivals thus giving intermittently a total storage capacity for the yard of approxi mately 200 cars. The amount of ore stored at any one time, howeve

Jan 1, 1926

By E. V. Kleber, V. F. Novy, R. C. Vickery

The constitutional diagram has been determined in part for the sgstem Gd-Fe. Seven intermetallic compounds have been found at compositions corresponding to the following Gd-Fe ratios; 2:3, 1.2, 1:3, 2:7, 1:4, 1:5, and 2:17. The GdFe, com-pound has a congruent melting point above 18000C, whereas all of the remaining compounds melt incongruently, A eutectic exists at 13 wt pct Fe at a temperature of 860°C. ALTHOUGH an increasing amount of information is becoming available on the metallurgy of pure rare earth metals, relatively few studies have been made on alloy systems of the rare earths with the transition metals; iron, nickel, and cobalt. Even less data are extant on gadolinium alloys although it could be expected that such alloys might possess interesting structural and magnetic properties. In this paper, we report investigation of the gadolinium-iron alloy system. Studies on systems containing nickel and cobalt will be presented in subsequent papers. Previous data on gadolinium-iron compounds have been reported by Endter and Klemm1 and Jep-son and Duwez.2 Both reports agree on the existence of the GdFe2 phase, which crystallizes with the C-15type structure (face-centered cubic). This is in accord with results of the present work. EXPERIMENTAL The gadolinium metal used was prepared by met-allothermic reduction of high purity gadolinium fluoride. A typical analysis of the metal thus produced indicated the principal impurities to be oxygen, 0.24 pct, and tantalum, 0.2 pct. The iron metal used for alloying was a reagent grade material. Alloys were prepared by arc melting mixtures of the respective metals. Appropriate quantities of the two component metals were carefully weighed, blended and compacted. The compacts were then melted in an arc furnace consisting of a water-cooled copper hearth plate and a water-cooled tungsten-tipped counter electrode contained in a brass vacuum chamber. The furnace was evacuated to an absolute pressure of less than 1 with the leak rate established as being less than 20 per min. The furnace was then back-filled to a pressure of 25 mm of Hg, with a 75 pct He-25 pct Ar mixture. Arc melting at 25 v and 300 amp was maintained for about 30 to 60 sec until the entire visible area of the sample became molten, by which time surface tension had drawn the molten metal pool into a large bead. After allowing the furnace to cool, the alloy button was inverted and the melting process repeated. A series of melts was made covering entire composition ranges from 100 pct Gd to 100 pct Fe. All samples were examined metallographically in the as-melted condition. As the phase diagram became rationalized, and differential thermal analysis had given indications of temperature arrests, annealing was carried out in vacuo or in argon. Generally, compositions containing more than about 60 pct Gd were heat treated at 750°C and alloys containing less than this quantity of gadolinium were annealed at 1000°C. Prolonged annealing times were of the order of 100 to 200 hr. Metallographic examination was repeated on the annealed materials. Although little material loss was noted during alloy preparation, chemical analyses were made on all specimens prepared. The following standard, analytical techniques were used. Samples were dissolved in hydrochloric acid; insoluble material was filtered off, ignited and fused with potassium pyro-sulfate. The cold melt was leached with dilute acid and the solution thus obtained added to the main sample solution. Gadolinium was always determined gravimetri-callv as oxide from oxalate ignition. Iron was removed from an aliquot sample by electrolysis on a mercury cathode at approximately six volts. Gadolinium in the iron-free electrolyte was then precipitated as oxalate which was subsequently ignited to oxide. Iron was determined volumetrically in an aliquot solution by reduction with stannous chloride fol-

Jan 1, 1962

By B. E. Sundquist

The various methods based on solution models for obtaining free energies of mixing from miscibility-gap data have been applied to a number of binary-alloy systems. For nine of these systems there exist experimental thermodynamic data that permit a comparison of the results to experiment. It was found that the method of van der Toorn and Tiedema almost invariably leads to results that are physically unacceptable and that vary drastically with small changes in the miscibility-gap parameters. The subregular solution model is found in all cases, except the Al-Zn, Fe-Cr, and Cu-Pb systems, to exaggerate the free energy of mixing by 30 pct or more. The model developed by Lumsden is found to give results that are often in excellent agreement with experiment and which exaggerate the free energy of mixing by no more than 30 pct. These results and others give evidence that the Lumsden treatment of the effect of unequal atomic sizes and of imperfect configurational randomness due to deviations of AB bond energies from the mean of AA and BB bond energies is adequate for most systems. ANALYTIC expressions are frequently proposed for the dependence on composition of the activities of the components of a solution. Because the development of solution theory is incomplete, these expressions contain parameters which must be determined by experiment. The measurement of activities is often difficult and consequently such measurements are less readily available than are measurements of phase equilibria which, under certain conditions, can also be used to evaluate these parameters. For example, suppose it is known that two structurally dissimilar phases, each of known composition, in an n-com-ponent system are at equilibrium at a given temperature and pressure. n equations can be set up in terms of these parameters expressing the equality of the chemical potential of each component in the two phases. In addition, one can write the Gibbs-Duhem equation for each phase that also contains these parameters. Thus, if these n + 2 equations contain n + 2 parameters, these parameters can be determined (at the temperature in question) from the phase diagram alone. If the average number of parameters in each expression for the activity of a given component in a given phase is V then there will be 2nV parameters involved. Equating 2nV to n + 2 shows that, for n + 2, V = 1. If the temperature dependence of each parameter were to be expressed in some explicit form one could use equilibrium conditions at a number of temperatures to increase V. The situation is much improved when the two phases in equilibrium are structurally similar. It can then be assumed that, stably or metastably, two phases will become one at higher temperatures. Thus the number of parameters involved becomes nV instead of 2nV. Hence, V = 2 for n = 2 using only one temperature. (It is implied here that the activity expressions used are valid over the entire composition range.) In this investigation only the equilibrium of two structurally similar, two-component phases (miscibility-gap systems) will be considered. The various proposed solution models will be applied to a number of these systems and the results compared with available experimental results. All of the analytic expressions that have been proposed for the free energy of mixing of a two-component system are of the form where ?Gmix is the free energy of mixing per mole of solution, N1 and N2 are the mole fractions of components 1 and 2, respectively, and f(Ni, T) is some function of composition and temperature. In the "ideal" solution model f = 0. In the "regular" solution model f = a constant. Since these two models permit only a symmetric equilibrium diagram they will not be considered further here. The simplest model that permits a nonsymmetric miscibility envelope is the so-called "subregular" solution model proposed by Hardy.1 This model gives where the Ci(T) are functions of temperature only. The same expression for f is obtained from the "linear a function" model proposed by Darken and Gurry2 and applied to miscibility-gap systems by Wriedt.3 This model requires that the a function defined by be a linear function of composition (yi is the activity coefficient of component i). This model is not purely hypothetical for it has been found2 to hold true for a number of systems. It is readily shown3 that the f(Nl, T) obtained from this model is of the form given in Eq. [2]. It will be noted that the subregular solution model contains only two parameters and hence both of them can be determined at any desired temperature below the critical temperature, Tc, for a miscibility-gap systems in the manner described previously. At T, the two constants can be determined by equating the second and third derivatives of ?Cmix with composition to zero. Another two-parameter model was proposed by Lumsden4 who set

Jan 1, 1967

Discussion of the paper of C. A. HEBERLEIN, presented at the New York meeting. February, 1915, and printed in Bulletin No. 98, February, 1915, pp. 497 to 504. H. D. PALLISTER, State College, Pa. (communication to the Secretary).-Mr. Heberlein gives some valuable information concerning a branch of mining and metallurgy which has been neglected during the last few years. His results with fine grinding and Deister tables suggest the possibility of the mining and concentration of a number of low-grade cinnabar deposits. Can Mr. Heberlein give us some idea as to the loss of quicksilver during this concentration? The advances in the metallurgy of quicksilver have been few and far between in recent years. Most miners prefer to go on in the old way with the Scott furnace and the large brick condensers. The large brick condensers are expensive to build and to keep in repair, and on account of the thick walls are extremely slow in cooling the gases; and further, the joints between the bricks offer passages for the quicksilver vapors unless great care is used in building the condensers.. The escape of vapor at the top of the furnace is another source of loss and I see the people at the Oceanic mine have overcome this in a very ingenious way. I recently returned from the Terlingua quicksilver district of Texas, where the only operating company, the Chisos Mining Co., is operating a 20-ton furnace of the Scott type. They had considerable difficulty with getting a good extraction, clue to too high heating in the furnace with its .resulting diffIculties. Recently they have been running with ashpit and fire doors closed and have been able to keep the heat lower, thus getting much better results and practically verifying the results obtained at the Oceanic mine.

Jan 5, 1915

By O. C. Wheeler

Peru, if it is judged on a basis of its annual production rate, can be ranked seventh among the oil-producing countries of the Western Hemisphere. In 1945, as in each of the three previous years, the country again produced about 14 million barrels of crude petroleum.

Jan 1, 1946

Jan 1, 1891

By K. Heindlhofer

Estimates of the "plasticity" of a metal are commonly deduced from three types of test—tensile, torsion and impact. The several results have been more or less at variance, though this disparity has attracted little notice, largely perhaps because they have been expressed in different terms. The discrepancy between the results of the three tests becomes obvious when each is made at a series of low temperatures, for the temperature range within which the "plasticity" of iron largely disappears proves to be very different in the three types of test. The rather abrupt disappearance of "plasticity" of iron within a narrow temperature range cannot be due to any physicochemical change (such as a precipitation) taking place in the material at that time, because the original plasticity is immediately regained when the temperature of the material is brought above the sensitive range. Accordingly this difference in behavior shows that the "plasticity" of a metal depends upon the mode of action of the stresses which produce the deformation, and therefore upon the method of test. Analysis of the stresses leads to the conclusion that the observed plasticity of a metal is determined by the relation between its resistance to rupture by separation and its resistance to shear (slip), on the one hand, and between the effective normal and shearing stresses on the other; and that the relation between the two resistances does not in general remain constant with change of temperature, and may somehow be altered to some extent by the previous treatment of the specimen. This suggests the view that the results of none of the usual mechanical tests are directly comparable even for a single metal tested at a series of temperatures, or for a series of metals at one temperature, because the proportion of the total resistance of the metal to the test contributed by the

Jan 1, 1935

By K. Heindlhofer

Estimates of the "plasticity" of a metal are commonly deduced from three types of test—tensile, torsion and impact. The several results have been more or less at variance, though this disparity has attracted little notice, largely perhaps because they have been expressed in different terms. The discrepancy between the results of the three tests becomes obvious when each is made at a series of low temperatures, for the temperature range within which the "plasticity" of iron largely disappears proves to be very different in the three types of test. The rather abrupt disappearance of "plasticity" of iron within a narrow temperature range cannot be due to any physicochemical change (such as a precipitation) taking place in the material at that time, because the original plasticity is immediately regained when the temperature of the material is brought above the sensitive range. Accordingly this difference in behavior shows that the "plasticity" of a metal depends upon the mode of action of the stresses which produce the deformation, and therefore upon the method of test. Analysis of the stresses leads to the conclusion that the observed plasticity of a metal is determined by the relation between its resistance to rupture by separation and its resistance to shear (slip), on the one hand, and between the effective normal and shearing stresses on the other; and that the relation between the two resistances does not in general remain constant with change of temperature, and may somehow be altered to some extent by the previous treatment of the specimen. This suggests the view that the results of none of the usual mechanical tests are directly comparable even for a single metal tested at a series of temperatures, or for a series of metals at one temperature, because the proportion of the total resistance of the metal to the test contributed by the

Jan 1, 1935

CYRIL STANLEY SMITH, Chairman CARL E. SWARTZ, Past-Chairman ARTHUR PHILLIPS, Vice-Chairman E. E. SCHUMACHER, Vice-Chairman H. A. MALONEY, Treasurer FRANK. T. SISCO, Secretary 9 West 39th Street, New York, N. 1. Executive Committee 1944 1945 WILLIAM C. ELLIS C. S. BARRETT ALAN MORRIS T. A. WRIGHT KENT R. VAN HORN L. L. WYMAN

Jan 1, 1943

By James Barr

The process of manufacturing ferrophosphorus lies not alone in smelting a mixture of phosphates, silica, iron ore, with coke as fuel, but upon smelting this mixture with coke and air as chemical agents as well as heat producers and in conjunction with extraordinary procedures and manipulations making the process continuous and profitable. For best results there must be cool top, limited fusion zone, hot bottom, good mechanical condition of stock and perfect distribution of gases; also minimum air supply, high heats and excess of coke or carbon. FERROPHOSPHORUS, an alloy of phosphorus and iron or perhaps a physical mixture of definite compounds of iron and phosphorus, has become of increasing importance as the use of the basic open hearth has extended. Commercial ferrophosphorus is a porous, brittle metal of crystalline structure and often with a bluish metallic luster. A typical analysis is as follows: PER CENT. Phosphorus 18.0 to 22.0 Iron 80.0 76.0 Oxygen 0.2 Sulfur : 0.3 Silicon 0.1 Carbon : 0.1 Manganese 0.2 This alloy was first made in an electric furnace, as it was thought that the high heat of the electric arc together with the reductive effect of carbon was necessary. About 1898, J. J. Gray, Jr., was producing a high-phosphorus pig iron in his furnace at Rockdale, Tenn., by using high-phosphorus, local iron ores. As these high-phosphorus ores were difficult to obtain, he conceived the idea of increasing the phosphorus content of the pig iron by the addition of phosphate rock to the furnace burden. When the phosphorus content of the pig was kept low and only small amounts of phosphate rock were added to the burden, no particular troubles were encountered, but when he increased the amount of phosphate rock to produce an 18 per cent. alloy, his furnace troubles rapidly multiplied.

Jan 10, 1924

By K. G. Wikle, J. G. Klein, W. W. Beaver

Consolidation of hydride process, electrolytic, calcium reduced, and comminuted thorium powder, as well as saw chips and lathe turnings, by vacuum hot pressing and by cold pressing-vacuum sintering was studied. The mechanical properties of the consolidated material in the extruded form are compared with those of wrought castings. AT present there little little industrial use for thorium metal, although it has some important though small scale applications in electronic equipment. Despite its high inelting point—about 1750°C —a low modulus of elasticity, 11.4xl0 si at 20°C;' relatively low mechanical properties coupled with a high density, 11.7 g per cu cm; and an unusually high chemical activity with normal atmospheres limit any structural applications. The metal is utilized as an alloying element principally in magnesium. Pure thorium finds utility as electrodes in gaseous discharge lamps such as the high intensity mercury lamp' because its low work function and high electron emissivity provide lower starting potentials and more uniform operating characteristics than other available materials. The metal is also found in photoelectric tubes used for the measurement of the ultraviolet spectrum." Thorium metal has been used in germicidal lamps of the cold cathode type as sputtered coatings on nickel in order to provide a low work function surface and a low starting voltage. Other applications have involved the radioactive properties of thorium for the production of ionized particles." The potential value of thorium is much greater than its present use pattern because of possible utility in the field of nuclear power. Th may be converted through nuclear reaction to a fissionable element U which should be capable of acting similarly to U in the g'eneration of atomic power. Thorium has been reported to be about three times as plentiful as uranium in the earth's crust, placing it in the order of abundance of lead and molybdenum." Thus, it is of interest in augmenting the potential supply of fissionable material for nuclear power. Because of its high melting point, thorium is usually produced as a powder through the calcium reduction of its oxide or thermal reduction of halides by sodium, magnesium, and calcium. It may also be produced in flake form by electrolysis of fused alkali or alkaline earth chloricles and fluorides. Therefore, powder metallurgy assumes importance in the fab- rication of thorium metal shapes. Furthermore, it is rather difficult to obtain pure thorium by melting, as the molten metal reacts readily with graphite as well as oxide, carbide, and nitride refractories. These contaminate the melt with oxides, carbides, and metallic impurities." The current investigation was undertaken to examine the fabrication of thorium by powder metallurgy methods which have been used for the commercial production of beryllium and other metals.' A sparcity of data concerning the comparative cold and hot compaction of thorium powders of different derivation existed. Therefore, all commercially available types were examined along with other experimentally produced thorium powders in order to round out the comparison of consolidated thorium powders with melted reguline metal. Review of the Literature By heating a mixture of ThC1, with potassium, Berzelius made the first thorium metal as an impure powder in 1828. Improvements in the basic process, increasing thorium assay to 99 pct, were made by several investigators including Arsem," Lely and Hamberger10 and Von Bolton." Calcium reduction of Tho, to make powders was investigated by Berger," Huppertz,'" Kroll," and Kuzel and Wedekind.'" A thorium powder produced by this method using a CaC1, fluxing agent assayed 99.7 pct, as reported by Marden and Rentschler.'" Compacted and sintered, this product was found to be ductile, and could be fabricated into wire and sheet. Improvements of the calcium reduction process were made later" wherein CaCl, was eliminated from the reaction, producing metal assaying 99.8 pct Th. Further work by Lilliendah118 howed that a coarser metal could be obtained by the substitution of ThC1, or ThOC1, for oxide with consequent advantage of stability to atmospheric reaction. Reports on the technology of thorium developed in Germany during World War II have been made by Espe."' Thorium powder of 99.5 pct Th was obtained by reduction of the oxide by calcium. Screening to —200 mesh, compacting with about 20 tsi, and sintering in vacuo at 1320" to 1360°C for 3 hr resulted in a porous sinter cake. The sinter cake was sufficiently ductile to be worked into bar, wire, and sheet which could be employed as electrode materials.

Jan 1, 1957