Search Documents

By ANTON GRAY

In considering the possibilities and costs of discovering minerals by exploration. mineral occurrences may be classified roughly according to the size of the target they offer to the various methods that have been used to search them out. This classification is advantageous because the methods of search which might be expected to give results in one case may be totally inapplicable in others. Mineral deposits for the most part have been found in groups, or districts, in which the individual deposits occur under the same general geological conditions and usually contain more or less the same metals. There are, also, what are apparently isolated de- posits, although if the truth were fully known many of these probably would not be isolated. These districts, such as the Belgian Congo copper fields, the California Mother Lode, and the Linares lead district of Spain, form the first division of my classification. The second division is formed of the individual deposits of these districts, for example, Kambove mine in the Congo, the Kennedy-Argonaut vein in California, and the Cruz vein at Linares. The third division consists of the separate ore bodies that make up the deposits

Jan 1, 1949

By NEWTON C. MARSHALL

AS every school boy knows, the Andes mountain range forms the backbone of South America, extending the full length of the continent along its western edge and fairly close to the Pacific coast. But in Colombia these mountains are divided into three distinct ranges known as the Western, Central and Eastern ranges of the Andes. United at the southern end, they spread out like three fingers in a northerly direction across the Republic of Colombia. These great natural barriers have only in recent years been tarried by railroads or wagon roads, and they have had their effect upon the history of the country, both political and ethnological. Each of the three ranges dies out and dwindles away before reaching the boundary of Colombia on the Caribbean Sea. When I studied my geography as a youngster 1 used to think that the

Jan 1, 1935

By AIME AIME

THE many kinds of iron and steel may be grouped into two general classes. First, there are the common steels and cast irons, made in enormous tonnages each year and used for the construction of buildings, ships and bridges, for pipe, for reinforced concrete highways, for the so-called tin cans, and by the railroads and other industries for which a low cost material is suitable. Second, there are the alloy steels and alloy cast irons, which are alloys of the chemical element iron and one or more of a large number of special elements such as manganese, silicon, nickel, chromium, vanadium, tungsten, and molybdenum. Alloy steels and irons are more costly than the common grades but their higher cost is, for many applications, justified by their superior properties, leading to ultimate economies or other advantages. They may be harder, stronger, tougher, or more resistant to rusting than the common varieties, and so are extensively used for tools, for ornamental work on buildings and in the automotive, aircraft, and other industries for, which the higher cost is compensated for by the higher quality.

Jan 1, 1933

By J. S. Marsh, T. B. Winkler

THE past year, the first full one of peacetime production, proved that the process of beating swords into plowshares has increased in complexity in step with civilization. Further, judging by various remarks of our distaff departments, the crystal balls of certain radio and magazine oracles must have been cloudy, because we have been in formed from time to time that coveted items such as automobiles and refrigerators did not appear in great abundance. This seemingly extraneous matter is really not out of place here, however; the steel producer and the fabricator exist in a sort of symbiosis: the making of consumer goods produces scrap which is returned to the steelmaker who makes more steel, and so on and so forth. Thus, no abundance of automobiles, no abundance of scrap from this normal source; and other sources had been picked pretty clean during the war. To be short, so was scrap. Since the economy of the steel industry lean; as heavily upon iron from scrap as upon iron from ore, the statement on transformation of swords to plowshares follows. But this is not the whole story: after all, ingot production was a record for a peace year!

Jan 1, 1947

By Schumacher, Earle E.

THE solidus line above the solid solution field in the lead-antimony system was originally determined by Dean and his associates1 from heating curves. They did not regard this line as having been accurately fixed and in their more recent publications2 the curves drawn do not follow closely the original data. The precise location of the solidus line is of importance in the extrusion of lead-antimony cable sheath, as the temperature of the metal in this process must be less than the lowest temperature at which any part of the alloy in the lead-press charge becomes liquid. It is very desirable, however, to operate at as high a temperature as possible, as the rate of extrusion for a given pressure is approximately doubled for an increase of 10" C. in temperature. The precise location of this line is also important in the investigation of ternary systems of lead, antimony and a third metal. For these reasons, and because of the differences reported in the literature, data were secured on the lead-antimony solidus line by the classical quenching-test procedure.

Jan 1, 1927

By B. W. Howlett, M. B. Bever, Somnath Misra

The heats oj- formation at 0°C of the compounds AuSn,, AuSn2, AuSn, and the £ phase were measured in a metal -solution calorimeter with liquid tin or a liquid Sn-Bi alloy as solvent. The melting point, heat of fusion, and heat capacities near the melting point of- the compound AuSn in the solid and liquid state were measured in a constant temperature gradient calorimeter. The free energy and entropy of formation of the compound AuSn at its melting point and at 298 °K were calculated from the experimental results and published data. The heats of formation are discussed in relation to the nature of the compounds. The heat capacity below the melting point, heat of fusion, and entropy of fusion of AuSn are interpreted in terms of processes oc-curring before melting. The atomic arrangement in liquid Au-Sn alloys and the bonding in the intermediate phases of. the Au-Sn system are discussed in the light of the measured thermodynamic properties. THE available thermodynamic information on the intermediate phases in the Au-Sn system consists of the heats of formation of the compounds AuSn4, AuSn2, and AuSnly2 and of one composition of the < phase2 besides values of the heat content of the compound AuSn from 0" to 635".&apos; However, the heats of formation refer to different temperatures ringing from 90" to 450°C. Also, the reported error limits of some of the values are large and several inconsistencies are apparent. In the investigation reported here the heats of formation of the compounds AuS-, AuSnz, and AuSn and of three compositions of the < phase were determined for a single reference temperature of 0°C by liquid metal-solution calorimetry. The compound AuSn, which is the only congruently melting intermediate phase in this system, was further investigated in a constant temperature gradient calorimeter by measuring its heat of fusion, melting point, and heat capacity in the solid and liquid states near the melting point. From these data and published free energies of the liquid of composition Au~n,&apos; the free energies of formation of the compound AuSn at the melting point and at 298°K were calculated. The results shed light on the solid-liquid transition of AuSn and on the atomic bonding and state of association of gold and tin in the solid and liquid phases. 1) EXPERIMENTAL PROCEDURES 1.1) Preparation of Samples. Stoichiometric amounts of gold and tin, each 99.99+ pct pure, were melted in evacuated Vycor capsules (12 mm ID). The melts were maintained approximately 150°C above the liquidus for about 12 hr and shaken repeatedly. Samples of the compound AuSn were cooled slowly to room temperature. Melts of the other phases, all of which solidify by peritectic reactions, were transferred to the narrow end (5 mm ID) of the capsule, which was then quenched into iced brine. The solidified samples were annealed in the unopened capsules for 10 days at 30" to 50° C below the respective solidus temperatures. The absence of microsegregation and second phases was confirmed by metallographic examination. At least two batches of each composition were prepared. 1.2) Solution Calorimetry. The heats of formation were determined by liquid metal-solution calorimetry. In this technique, the difference between the heat effects on dissolution in a liquid metal, or alloy bath, of the compound and a mechanical mixture of its annealed components, adjusted for changes in composition of the bath, is the heat of formation of the compound at the temperature from which the samples are added. Details of the equipment and technique have been described."&apos; A tin bath at 300" or 350°C was used with the compounds AuSn,, AuSnz, and AuSn. The high gold content of the £ phase would have caused it to dissolve with an appreciable exothermic heat effect. In order to achieve thermal compensation, the samples were added from 0°C to a bath at 350°C consisting of 66.2 wt pct Bi (99.999+ pct pure), balance Sn (99.99+ pct pure). This solvent gives thermal compensation because gold dissolves exothermically in tin and endothermically in bismuth. The calorimeter was calibrated by adding from 0°C approximately 0.015 g-atom of the solvent.

Jan 1, 1965

By AIME AIME

THE meeting" of the Rare Minerals and Metals Committee was held Monday afternoon, Feb. 17; Donald M. Lidclell, chairman, presiding. The first paper (T. P. 279), "Progress in the Use of Tantalum," by George W. Sears, was read by Mr. Smyth. Dr. Sears&apos; paper contains an interesting summary of the uses, alloys and ores of tantalum and a resume of present method of reduction. The uses of tantalum is based on its extreme rise to the reaction of even the strong mineral acids, its great avidity for the common gases and its capacity for transforming alternating to direct current. Tantalum, as an alloy material, has received considerable study and many alloys have been reported. Among them three types appear to .be most prominent, alloys of high melting point, hard alloys and acid rising alloys. As the estimated quantity of tantalum in the earth&apos;s crust is less than that of gold, it must be looked upon as n rare metal. Australia is the greatest producer and the Black Hills of South Dakota produce minor amounts. As the one type of mineral available contains both tantalum and columbium, the extracting and metallurgy of tantalum are difficult chemical processes. Greater simplicity in this and the development of a market for columbium would undoubtedly be of great benefit to the tantalum industry, andl make for a greater use of tantalum produced.

Jan 1, 1930

By Murray F. Hawkins, Marion L. Kimmel

sage&apos; appears to have been the first (1933) to design a rolling ball viscosimeter for the express purpose of measuring the viscosity of oils with natural gas in solution, i.e., under reservoir conditions. In 1940 Hocott and Buckley&apos; further refined the rolling ball instrument in both design and method of operation, and their instrument, known as the Humble type, was the forerunner of present day viscosimeters used in petroleum production and research laboratories. They also initiated the technique of charging the viscosimeter with a sample directly from a bottom hole sampler. In 1948 the committee on engineering research 01 the Petroleum Division of the AIME in Part 3 (1) of

Jan 1, 1955

By J. J. Carrigan

IN all mining operations a considerable portion of the work performed, especially underground; is accomplished under artificial light, yeti this subject is often not given proper attention. Poor illumination decreases mining efficiency, impairs the sorting or grading of ores, and increases the risk of accidents. In the beginning, and for several years afterward in the metal-mining industry of Butte, Montana, candles placed in candlesticks were carried by the men. Sconces or holders for candles were also provided at stations and curves in drifts to furnish better light for men engaged in. hand tramming. It was also common practice to place clusters of candles on the ground, with no provision for guarding against an underground fire other than the exercise of sufficient care by the men themselves. An accumulation of candle grease from this source was the direct result of the first serious fire in the Anaconda mine, in 1889.

Jan 1, 1936

By H. Rosenthal, A. L. Jamieson

The action of mercury on stressed brass to produce cracks was known before Moore, Beckinsale and Mallinson1 showed that actual season cracking did not occur spontaneously but could be induced by ammonia. These investigators studied other substances, including diphenylamine, without finding that anything other than ammonia could cause season cracking Grimston2 reported season cracking in cartridge cases stored in wooden boxes wetted with dilute sulphuric acid pickling solution. Season cracking associated with sulphur dioxide, water vapor and air has been reported by Johnston,3 although he reported that trimethylamine and pyridine did not cause cracking. Jevons4 has ascribed season cracking of brass in certain instances to trimethylamine, "aldehyde amine," "ketone amine" and pyridine, but no experimental work was done evidently to prove this definitely. Pyridine was investigated by Morris,5 who found it to have considerable cracking power. In the present investigation, the object was a qualitative evaluation of a number of representative amines with respect to their ability to cause season cracking. Thus it was desired only that an appreciable vapor pressure of each amine be obtained in order to make the test as severe as possible, without attempting to test equivalent concentrations for comparative purposes. MEthods Specimens TWO types of specimen were used: 1. Unannealed 70-30 brass CUPs formed from 0.040-in. thick sheet. Height of cup Was 13/8 in. and diameter was 17/8 inches. 2. First draw pieces of caliber .50 cartridge cases in the unannealed condition (70-30 brass)- The cups were representative of a thin wall and thin base specimen, whereas the draw pieces have a thick base (1/4 in.) and a thick wall (approximately 3/32 in.). Both types of specimens contained high residual stress and cracked in less than one minute in a solution of I per cent mercurous nitrate and I per cent nitric acid provided that this was receded by a 30-sec. pickle in 40 per cent nitric acid. Specimens were prepared as follows: (1) degreased in trichlorethylene, (2) rinsed in H2O, (3) pickled 5 min. in 10 per cent by volume H2SO4 (1.84 SP. gr.), (4) rinsed in H2O, and (5) dried. Amirtes Tested In selecting the amines, representatives of the three series of amines, and one series of substituted amines were chosen. The aliphatic series was represented by the methyl and ethyl primary, secondary and tertiary amines. These are the simplest aliphatic amines. For the aromatic series, the phenyl primary, secondary and tertiary amines were selected as being the simplest. The heterocyclic series was represented by pyridine, which is a simple heterocyclic base (tertiary amine).

Jan 1, 1944

By M. D. Hassialis, Arthur F. Taggart

WARK1 observed some years ago that collector-coating reactions with xanthates and with fatty acids clearly follow paths parallel to those prescribed by the familiar mass-action law for reactions in dilute solutions. He proposed, therefore, the logical hypothesis that they are governed by the solubility=product principle. However, he went astray in the application of his proposal to collector coating by overlooking the fact that coating involves a heterogeneous reaction. A mistaken concept of the meaning of the word adsorption also entered. Wark thought that the concentration of metallic ion that must be used in setting up the solubility-product equation for the coating reaction was that which could be obtained by solution of the mineral. Since this is very low for sulphide ores, and since the amount of the collector ion necessary for coating produces an extremely low concentration, the resulting ion-concentration product, under conditions when coating occurs, is much lower than that which would indicate a saturated solution of the collector-coating compound. Hence he was forced to the position that the solubility product governing the coating is much smaller than the standard solubility product. To justify this position it was necessary to postulate a coating mechanism that did not obey the ordinary laws of chemical reaction. This Wark did by adopting the concept that adsorption is a property of matter, rather than merely a more or less ephemeral local concentration thereof. Thus he says (p. 142 of ref. I): "Adsorption is not a purely physical property of the solid surface, for the specific nature of the adsorbed molecule or ion is important." The result was that he destroyed the great potential utility of his postulate by tying it to this erroneous concept in the words (pp. 142, 143): "It will be obvious that the adsorption solubility product is less than the normal solubility product." The writers have found quantitatively in the case of galena and potassium ethyl xanthate, and semiquantitatively in the case of covellite and the same collector, that the coating reaction does follow the mass-action law to the extent that coating occurs when the ordinary solubility product of the coating compound is exceeded, and that coating does not take place under the reverse conditions. In the course of the investigation leading to the establishment of this fact it was necessary to work with xanthate concentrations so low (down to 0.0004 mg. per liter), that very long conditioning times, and bubble-contact times of as much as 16 hr. were necessary sometimes to follow the reactions. The results have led to some illuminating conclusions as to necessary collector concentrations in normal flotation operations, and the action of the frothing agent in connection therewith. The experimental work comprised. accurate determination of the standard solubility product of lead ethyl xanthate, development of a much less laborious

Jan 1, 1946

By REED H. HYDE

IN these days of low metal prices and difficult marketing conditions, any treatment that will improve the grade of a product is of interest, particularly when the operation involves little or no addition to the total cost and may even result in a marketable by-product. Such a&apos; combination of circumstances exists, in some cases, in the zinc industry, where it has been found that certain impurities can be removed from .the ore during the Dwight-Lloyd sintering operation, previous to reduction to metal. Consequently it is not surprising that zinc smelters having these sintering machines are paying particular attention to this phase of the operation. Loss of zinc as fume is very low under the conditions obtaining in sintering zinc ores, but impurities such as cadmium and lead are more readily fumed off and it is on this fact that the purification is based. As a result of preferential volatilization of these impurities a sintered product&apos; is made from which purer zinc metal or oxide can be produced, while the fume may be collected and treated to recover the impurity metals. To be effective the operation must be carefully conducted, but no special equipment other than that of a well designed Dwight. Lloyd plant is needed.

Jan 1, 1931

By Edward W. Parker

This plant was built in 1907 at the Bankhead mines to manufacture briquettes by the Zwoyer process under license from the Zwoyer Fuel Co., of New York, N. Y. The building was constructed to contain two units, each of a capacity of 10 tons per hr.; one unit was installed at the time the building was constructed, and the second unit is now being built. The coal used is an anthracite, which is more friable than that of Pennsylvania, and, as a consequence, a larger percentage of dust or waste is produced, which was formerly thrown upon the slack-pile as waste, but is now passed to the ? dust-bin " in the breaker, from which it is conveyed to the briquette-plant.

Jan 5, 1908

By R. T. C. Rasmussen, L. H. Banning, W. E. Anable

In the rapidly growing industry of elemental-phosphorus production from western phosphates, most of the vanadium and chromium contained in the phosphate rock collect in the byproduct ferro-phosphorus. Results are presented of a completed laboratory project, which developed a tristage crystallization and hydrolysis process for recovering strategic vanadium and chromium, as well as a valuable phosphorus product, after extracting these elements from the ferro-phosphorus by roasting and leaching. THE Phosphoria formation in Idaho, Montana, Wyoming, and Utah contains the Nation&apos;s largest reserve of phosphate rock. A unique feature of the Phosphoria beds is their content of a fraction of a percentage each of vanadium, chromium, nickel, and molybdenum. Vanadium is the most important as to quantity and value. Small-scale tests by the Bureau of Mines at Albany, Oregon, in 1947, indicated that most of the vanadium in the phosphate rock collects in the ferrophosphorus product of smelting. Subsequent electric smelting operations to produce elemental phosphorus from western phosphate rock (experimentally by TVA and industrially at Pocatello, Idaho) have shown that the vanadium and other metals in the rock are to a large extent recovered in concentrated form in the ferrophosphorus byproduct. This paper reports the results of completed laboratory research on the recovery of vanadium from ferrophosphorus, which was undertaken by the Bureau of Mines at Albany in 1948 as the first phase of a project entitled, "Vanadium and Fluorine from Western Phosphates." The various vanadium-recovery methods investigated, including the roast-leach method that showed most promise and was studied in greatest detail, are discussed in an earlier publication.&apos; Subsequent systematic study of the roast-leach method of extracting vanadium from western ferrophosphorus developed the more effi- cient tristage crystallization process, which is the subject of this paper. Process Development The investigations were made on ferrophosphorus produced in the electric smelting of elemental phosphorus from western phosphate rock. The TVA provided two sample lots of ferrophosphorus produced in pilot plant smelting of phosphatic shale from the Fort Hall Indian Reservation in Idaho. The Westvaco Chemical Div. of the Food Machinery & Chemical Corp. supplied two sample lots of ferrophosphorus produced by its phosphorus smelter at Pocatello, Idaho. The analyses of all four lots are shown in Table I. Westvaco lot B was the starting material for the more recent tests. The roast-leach process for recovering vanadium from western ferrophosphorus, as originally developed, employed the following principal steps: Roasting of a mixture of pulverized ferrophosphorus, soda ash, and salt; extraction of the water-soluble vanadium, phosphorus, and chromium compounds from the calcine by leaching, settling, and decanta-tion of the pregnant solution; primary crystallization of trisodium phosphate from the pregnant solution; purification of the trisodium phosphate crystals by dissolution in water and secondary crystallization; purification of the pregnant vanadium solution from the primary crystallization step by adding calcium chloride to precipitate calcium phosphate; and hydrolysis of vanadium red cake from the puri-

Jan 1, 1954

By G. D. TRANT

HOT metal is commonly transported from the blast furnace to the open hearth by one or the other of two general methods: (1) by hot-metal ladles, usually in conjunction with a stationary mixer, or; (2) by means of mixer-type ladle cars, taking the place of both the hot-metal ladles and the stationary mixer. In both cases, the use of transfer ladles for charging the metal into the open-hearth furnaces is necessary. The American Rolling Mill Co. at its Middletown division, adopted hot metal practice on. June 2, 1928. The pig iron is produced&apos; in a .blast furnace about 11 miles from the open-hearth furnaces, and is trans- ported in Pugh-type mixer cars having a capacity of 150 gross tons each. Three cars are in service and handle the delivery of hot metal to the pig machine and the open-hearth furnaces. The capacity of the blast furnace is 550 tons and casts are made every four hours.

Jan 1, 1929

By L. L. Melton, D. L. Lord, B. W. Hulsey

A mathematical model d1.20p/4L = A(8v)8 derived from the Blasius equation is proposed to be applicable to turbulent flow through straight cylindrical pipe for time-independent fluids which produce a diameter family of straight parallel lines on a log (dp/4L) vs log (8v/d) plot or stress-flow diagram. Such a correlation should permit scale-up with data taken from one pipe diameter for Newtonian, inelastic non-Newtonian and viscoelastic fluids, such as dilute polymer fracturing fluids, which produce considerable frictional pressure reductions. The Newtonian diameter exponent value 1.20 is shown to be empirically valid for turbulent non-Newtonian flow by application of numerical analysis methods. Multiple regression analysis is applied to a logarithmic linearization of the proposed model. An improved data fit results from further linearization achieved by taking linear terms from a generalized Taylor&apos;s series expansion about the multiple regression coefficients. Extensive experimental data obtained in five pipe diameters with water, sodium carboxymethyl-celIulose solutions, guar gum solutions, bentonite clay suspensions and calcium carbonate slurries are presented. Except for calcium carbonate slurries, which were investigated rather than time-dependent cement slurries, the fluids studied contain drilling or fracturing fluid additives. The behavior exhibited by these fluids is considered typical of most fluids encountered in drilling, cementing and fracturing operations. INTRODUCTION Considerable difficulties have been encountered in predicting turbulent flow pressure drops produced by non-Newtonian fluids flowing through straight cylindrical pipe. Correlations previously presented require extensive experimental data which represent several pipe diameters and a wide flow rate range to estimate the necessary scale-up parameters.l-7 One must implement either elaborate experimental apparatus or spend considerable time and effort to gather these data. Presented here is a correlation method which should minimize the experimental effort and data analysis normally required by utilizing flow data taken with only one pipe diameter. Turbulent flow data (up-stream and down-stream pressure and volumetric flow rates) were collected for five pipe diameters through operation of a small pipeline system having an electronic data acquisition and digitizing system. A mathematical model derived from the Blasius equation was utilized to describe the functional relationship between pressure drop and the two independent variables, diameter and average flow velocity. A correlation, which should produce a valid single-pipe scale-up, resulted from a computer-implemented statistical and numerical data analysis for several time-independent non-Newtonian fluids.

By J. C. Jr. Vaughan

ALTHOUGH a considerable amount of practical importance attaches to systems involving gases and molten metals, little is known regarding the effects of alloy elements upon the solubility of gases in liquid iron. The solubilities of hydrogen1 and nitrogen2,3 in pure liquid iron are known and it has been shown that small amounts of silicon and aluminum3 exert only a small effect upon the solubility of nitrogen but greatly increase its rate of solution. This paper presents the results of a study of the Solubility Of nitrogen, at pressures approximately one atmosphere, in molten iron containing up to 1.5.5 per cent silicon.

Jan 1, 1939

By AIME AIME

DESPITE the meetings and discussions on over- production the situation still continues to grow worse instead of better. The demand for oil has dropped to 2,700,000 bbl. per day. On the other hand domestic production has risen to 2,700,000 bbl. with prospects of further increases, and if imports and natural gas-gasoline be added to this the current supply is about 3,100,000 bbl. per day. Though during the summer and early fall the demand may exceed this figure for a few months the prospects are that &apos;the average demand during 1929 will be at least 200,000 bbl. per day less than the present current supply, meaning additions to stocks over the year of about 75,000,000 bbl.

Jan 1, 1929

By Goodman, Richard E.

A complete rational analysis for design of excavation slopes and loaded rock masses is a desirable but perhaps unattainable goal. Irregular external and internal boundary conditions, poor understanding of failure criteria for large masses of rock, capricious material properties, and the importance of indeterminate forces and inaccessible and virtually un- sampleable rock defects emphasize the importance of experience in this aspect of rock engineering. The experience must be correlated with geological factors. In certain regions the accumulation of such experience through the observation of existing rock slopes in various formations constitutes an important aspect of studies for design of rock excavations.

Jan 1, 1969

By Nicholas J. Grant, Irmgard Rump, Bill C. Giessen

The system W-Hf was determined by use of metal -lographic and X-ray methods. The only interrnetal-lie phase W2Hf melts peritectically at 2650° ± 50°C. A eutectic between W2Hf and ß-Hf solid solution exists at 78 at. pct Hf arul 1930º ± 10°C. The addition of tungsten loulers the hafnium transfornzation; there is a eutectoid at 93 at. pct Hf and 1560°C. The solubility limits of the terminal solid solutions were determined. At the beginning of this investigation, the system had not been elaborated; only crystallographic work had been done to determine the structure of the occurring intermetallic compound W2Hf, and a certain analogy to the system W-Zr was to be expected. Special emphasis was placed in this program on the Hf-rich part of the diagram. Following the completion of our experiments, a phase diagram was suggested by Braun and RUdY.1 EXPERIMENTAL METHODS The investigation utilized tungsten powder supplied by the General Electric Co. with a purity of about 99.9 pct and hafnium crystal bar of about 97.7 pct purity, 2.3 pct Zr, supplied by Foote Mineral Co. Typical analyses are given in Table I. The procedures followed were identical with the ones described for the Re-Nb diagram.&apos; Tungsten powder was compacted at 16,000 psi and the necessary amount of hafnium was added in the form of small pieces cut from the crystal bar, with a reasonable excess of tungsten powder to make up for powder losses on melting. High hafnium or tungsten melts were prepared from premelted tungsten and hafnium or by employing master alloys. The melting was done in a Heraeus arc-furnace under argon. Melting and remelting up to 8 times resulted in fairly homogeneous alloys. No weight

Jan 1, 1962