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By R. K. Waring

A KNOWLEDGE of the mutual liquid solubility of zinc and lead is of importance in various phases of zinc metallurgy. The determination of this solubility has been the subject of numerous investigations, but unfortunatel, the results vary widely, particularly at higher tempera-tures, and it has been impossible to decide what data are most reliable. It was decided to investigate the matter and in view of the disagreement in the published results, it was felt necessary to take rather unusual precautions to insure the reliability of the data. For this reason deter-minations were made by four different methods, and the procedures of several of the previous investigators were duplicated. The previously used methods can be divided into two classes: methods involving freezing the entire melt and taking samples of the lead-rich and zinc-rich phases in the solid state, 1,2 and methods in which the. samples are taken while the bath is liquid and at the desired temperature. 3,4 Data obtained by methods involving freezing the entire melt show much lower solubility of lead in zinc than methods in which the liquid is sampled at temperature. The latter method was used by Spring and Romanoff5 and by Hass and Jellinek.6 The results of these two investi-gations are in agreement at temperatures near the melting point but at higher temperatures Hass and Jellinek find a higher mutual solubility.

Jan 1, 1934

By A. J. Opinsky

THE purpose of this note is to indicate the locations and sizes of various interstitial holes in the orthorhombic uranium lattice based on a hard-sphere model. First, plane configurations of three and four atoms will be examined, and then the true interstices surrounded by four atoms in space and by five atoms in space will be obtained. The data and notation contained in a report by Tucker' will be used. Plane Configurations Fig. 1 presents the orthorhombic uranium lattice made of spheres touching at the closest interatomic distance. The three light-colored spheres in the ab plane are illustrative of the first type of configuration to be examined. If one edge of the unit cell is taken as the origin, the three atoms can be represented by the vectors [Oi + Oj + Ok], [ai + Oj + Ok] and [(a/2)i + (b/2)j + Ok] where i, j, and k are respectively parallel to a, b, and c. In the future, this notation will be shortened to [000], [a00] and [a/2 b/2 0], respectively. A vector R = [r s t] de-scribes the position of the hole surrounded by the atoms. Since the center of the hole must be equidistant from the three atoms R2 = r2 + s2 + t2 = (r-a)2 + s2 + t2 = (r-a/2)2 + (s-b/2)2 + t2. R = [a/2 (b/4) - (a2/4b) 0] is the solution of these

Jan 1, 1955

By P. H. Royster

IN a study of the blast-furnace process, the Bureau of Mines has made many experiments for the purpose of determining the exact nature of the combustion of coke in the neighborhood of the tuyeres. Two papers1 presented at a meeting of this Institute discussed somewhat the practical aspects of coke combustibility in its relation to the operation of the blast furnace. In a later paper,2 Sherman and Kinney discussed the possible effect of variations in the combustibility of cokes on the furnace operation, and find that the "reoxidation theory" of Koppers and the "heat concentration theory" of Brassert3 are insufficient to explain the variation in the conduct of different cokes that has been observed by furnace operators. In their report to the D-5 Committee of the American Society for Testing Materials, with which the Bureau of Mines has been cooperating, Perrott and Fieldner4 seem to agree with Sherman and Kinney that, for practical purposes, the nature of the combustion of coke at the tuyeres of any furnace is constant and is affected neither by the physical properties of the coke nor by the nature of the furnace operation. They omit as unimportant any tests on the combustibility of coke from their proposed methods for standard tests on coke. In the last two papers, it is pointed out that performance tests, in which all other factors except coke quality are kept constant, are to be desired and

Jan 3, 1924

By B. D. Cullity

AS methods for measuring fiber textures become more exact, it becomes justifiable to scrutinize an observed pole-density curve for evidence of minor texture components. These are disclosed by minor maxima or abnormally broad major maxima. One possible source of these minor components is twinning of the main component. In cubic metals and alloys, there are two kinds of twins: 1) Annealing twins in face-centered cubic metals. These are reflection twins on {Ill), and they can be expected to be present in recrystallization textures. 2) Deformation twins in body-centered cubic metals. These are shear twins on (112). Although usually formed only by impact, they might conceivably be present in the deformation texture of severely cold-drawn wire. Fortunately, both kinds of twinning lead to the same orientation relationships. It thus becomes possible to prepare a single list of angles between various planes in parent crystal and twin, which is helpful in examining pole-density curves for evidence of twinning in any cubic metal or alloy. Such a list of interplanar angles is given in Table I. This table consists of three parts, corresponding to the three major texture components—<100>, <110>, and <111>-most commonly found in the fiber textures of cubic metals. The table lists the angle between the pole of {hkl}, in either the parent crystal P or the twin T, and the fiber axis <uvu>. The crystals with <uvw> parallel to the wire axis are here

Jan 1, 1959

By Richard H. Terhune

The use of water-cooled breast-jackets or cinder-tap blocks is a great convenience in lead-smelting, even when siliceous slags are made. If the charges are at all basic it is almost imperative. Jackets of riveted wrought-iron or steel are expensive; those of cast-iron are liable to crack; those of bronze are costly and not durable, being easily penetrated by tapping-bars or destroyed by streams of matte impinging against them. To overcome these objections I introduced at the Hanauer works, in April, 1886, castjackets of steel, which have been in constant use since that time and are to-day as good as new. These jackets were made for us by the Chester Steel Castings Company, of Chester, Pa., at a cost of ten cents a pound at the works of that company. The metal is 5/8-inch thick, and the jackets were cored and tapped for l1/2-inch bushings, affording two large holes for the removal of dirt and incrustations. The same holes are used for feed- and discharge-water through 3/4-inch pipe. I hope the successful introduction here of cast-jackets of steel will lead to their more extended use in all branches of metallurgy where water-cooled surfaces are severely taxed, and where the size and thickness of the castings are not unfavorable to the production of a sound article, impervious to water and of high tensile strength.

Jan 1, 1889

By Thomas H. Sheehan

The purpose of this paper is to present an application of computer technology to assist the mineral company financial executive in assessing exchange risks. The paper is divided into five parts: Background, Translation Approaches, Theory, Empirical Validation, and Conclusion. BACKGROUND Exchange risk results from a change in the rate of exchange between a host and a home country&apos;s currencies. Legitimate reasons exist for changes in the currency exchange rates among countries in a world with over a hundred different currencies. These reasons include: different economic growth rates, social factors, cultural heritages, and political motivations. The problem of exchange rate changes are perennial and exist whether the world operates on exchange rates or floating exchange rate practices. The cause of the problem is trade and international payment imbalances. If one accepts the premise that exchange rates fluctuate over time, then the mineral company financial executive faces a continual process of reassessment of the impact of exchange rate changes on the financial worth of his company. (1) The mineral company financial executive prepares balance sheets and income statements that are audited by certified public account- ants annually for shareholders, bankers, and tax authorities. The financial executive translates assets and equities denominated in foreign currencies into domestic dollars, e.g., Japanese firms convert to Yen, French firms convert to Francs, and so on. When figures from foreign subsidiary operations are consolidated into the balance sheets of the parent corporation, estimates of the company&apos;s finan-

Jan 1, 1977

By L. Dudley Stamp

The years 1935 and 1936 have been momentous ones in the history of oil exploitation in Burma. While the possibilities of the discovery of an important new field in the country have become increasingly remote, there have been surprising and to some extent unexpected developments in and near the old established fields. Further, these developments have not only an important bearing on the future of the industry in Burma, but they point to conclusions of, world-wide significance in connection with the disposition of oil pools. BC&apos;rma Independent of India According to the Government of India Act, passed by the British Parliament in 1935, Burma becomes independent of India, of which it was formerly a province. In future, therefore, statistics for Burma will be quoted separately from those of India. In 1934, 1935 and 1936 the oil production in India (including Burma) reached new high levels— though only a few per cent above the totals for 1919, 1920 or 1930. Part of the increase came from Assam, so that Burma&apos;s total is apparently below that of 1921. It must always be remembered, however, that Burma&apos;s largest potential producer—Singu—is used essentially by the Burmah Oil Co. as a reserve and its production is varied from year to year, and indeed from week to week, according to local market demand or the requirements of the Rangoon refinery. The figures of Table 1 must therefore be viewed in the light of these remarks.

Jan 1, 1937

By C. S. Desai

INTRODUCTION Behavior of joints in rock and interfaces in structures and geological media subjected to static and cyclic loading play an important role in analysis and design of structures founded on rock and soil foundations. The objectives of this paper are (1) to describe a device that can permit laboratory testing of joints and interfaces under translational and torsional motions, (2) to present procedures for constitutive modelling of joints and interfaces with a typical example of modelling of a concrete-sand interface, and (3) to give brief details of the proposed research plans for cyclic testing and modelling of joints in concrete as a simulation of joints in rock. The subject of testing and modelling of interfaces and joints is wide in scope, and in view of space limitations, it is not possible to provide a comprehensive review herein. Hence, only a few references, particularly relevant to the ongoing research by the authors and co-workers are included; a review of the subject can be found in (Desai, 1981) and (Heuze and Barbour, 1982). Although there can be (minor) differences in modelling for the behavior of joints and interfaces, the basic procedures can be considered to be essentially similar. Now onwards in this paper, the term joints will be used to imply both joints and interfaces. TESTING DEVICE Appropriate laboratory (or field) testing is an important and indispensable ingredient for constitutive modelling of joints. A new device has been developed for static and cyclic testing of

Jan 1, 1984

By P. St. J. Perrott

AN explosive of balanced composition might be expected, on first consideration, to develop maximum propulsive strength.1 This hypoth¬esis is based on the assumption that an excess of oxygen would act simply as an inert material with a consequent lowering of flame temperature, also that a deficiency of oxygen would tend toward incomplete reaction of the combustible materials, thereby preventing development of the full strength of the explosion. Actually, however, it can be shown both theoretically and experimentally that an explosive having a certain oxygen deficiency will develop the greatest propulsive strength. This fact has been known to the technical staffs of explosives manufacturers for many years, but it has not always been recognized by explosives engineers in the field. For example: There is a fairly widespread opinion that the wrapper of a stick of dynamite is merely a container for the explosive and that it plays little if any part in the development of propulsive strength. Actually, it can be shown that the wrapper enters fairly completely into the explosive reaction. In the case of most gelatin dynamites, a given weight of explosive from which the wrappers have been removed will develop considerably less strength than the same weight of explosive plus wrapper, in spite of the fact that the latter combination contains less weight of the actual explosive ingredient. It can also be shown that a cartridge 7/8 in. in diameter may be stronger, weight for

Jan 1, 1928

By Porter W. Shimer

It docs not seem to be generally known that some American pig-irons contain notable amounts of vanadium, and while the present investigation is far from covering the whole range of irons, it is hoped that, at least, it may serve to call attention to the importance of looking for this element. The majority of the pig-irons investigated were made in the Lehigh Valley and neighboring furnaces, using more or less New Jersey magnetite in their mixtures. Many of these ores, and probably all of them, contain a little vanadium as well as titanium; the ore from one of the largest of these mines contains 0.05 per cent, of vanadium and 0.60 per cent. of titanium. Dr. Thomas M. Drown was the first to detect the presence of vanadium in the incrustations1 occurring on certain pig-irons, and he also found this element in a number of magnetites, but the methods for its accurate determination had not, at that time, been well worked out. In a general way, it may be said that the Lehigh Valley pig-irons contain from 0.02 to 0.05 per cent. of vanadium and from 0.10 to 0.20 per cent. of titanium. These elements follow the silicon; that is, the furnace-conditions which produce a high-silicon, low-sulphur iron will cause the maximum reduction of vanadium and titanium, and

Jan 1, 1913

By Ben Gumpertz

THE important factors in any study of the screening of sand with a gravel enve-lope, as applied to use in oil wells, are: (r) sand size and shape, (2) gravel size and shape, (3) ratio of gravel size to sand size, (4) flow velocity, (5) viscosity of the fluid. Perhaps the first extensive investigation of the function of gravel in screening sand was performed by Coberly and Wagner,1 from which the following conclusion was drawn: "The diameter of the largest grains in a single classified sand suitable for gravel packing is approximately 23 times the grain size at the ten-percentile analysis of the formation sample." This applies to sands classified by Tyler screens and is for gravel grains of the maximum size that could be used to form a stable bridge. Field practice has shown that the screening effect of a given gravel for a given sand apparently varies with the flow velocity.2 Also, it has been assumed by some opera-tors that the thickness of the walls of the gravel envelope surrounding the well has little effect upon the screening process. It is thought by others that a narrow envelope of gravel might form an ineffec-tive screen. Thus the purposes of this work are: I. To investigate the effect of gravel-sand size ratio upon screening action under the condition of varying flow velocities. 2. To investigate the effect upon screen-ing action of varying the thickness of the gravel screen.

Jan 1, 1940

By M. R. Geer, J. D. Davis, H. F. Yancey

ALTHOUGH the mechanical cleaning of coal is carried out at plants on the surface, preparation is actually begun at the face in the mine. Here the character of the coal and the amount, character, and distribution of the impurities within the bed may be seen. Blasting methods, dust-allaying procedures, location of mining cut with respect to bands of impurity, and the practice of discarding segregated impurities underground, all have an important bearing on the successful operation of surface cleaning units. The most important single characteristic of both coal and its asso¬ciated impurities from the standpoint of cleaning is specific gravity. Other characteristics related in one way or another to the preparation of coal are rank, petrographic composition, structure and hardness, and friability. These and still other coal properties are discussed in the first section of this chapter and impurity characteristics in the second. COAL CHARACTERISTICS RELATED TO PREPARATION Rank As a result of work done over a period of several years by committees of the American Society for Testing Materials and the American Standards Association, standard specifications are now available showing the classification of coals according to rank and quality of grade.&apos; The term "rank" expresses the degree to which the original coal-forming material has been changed by metamorphism through successive stages from peat to anthracite. Table 1 shows the classification of coals according to rank as devised by the committees of the organizations mentioned. The basic scheme of classification for the higher-rank coals is according to

Jan 1, 1943

By H. A. Stacy

THE ability of galvanized sheet steel to withstand severe bending is of very great importance as relates to all such sheet material which, in service, is not used in the flat condition in which it is purchased. A "bend-test" clause is found in, all specifications for material of this kind. In the attempt to draw up a specification for galvanized sheet steel the subcommittee of the Federal Specifications Board having this work in charge, soon found that there was a surprising lack of published data and apparently very little available from manufacturing sources upon which to sustain or reject the various requirements embodied in the tentative specification which, in turn, had been based largely upon other specifications submitted to the subcommittee for this class of material. Specifications from 25 sources were received; 10 Government specifications, 10 from private users of such material, and five from manufacturers. The main points raised were: (1) The minimum mandrel thickness, expressed in terms of the thickness of the sheet tested, over which sheets with different weights of coating can be bent 180°, without serious damage to the coating; (2) the minimum radius of curvature on the inside of the angle in 90°-bends in such material; (3) effect of double seaming on the coating; (4) uniformity in the thickness of coating over a sheet, particularly as relates to the results of bend tests. In view of the uncertainty existing, it was considered very desirable for the subcommittee to conduct a series of tests in order to secure reliable information.

Jan 10, 1926

By Masayuki Otagawa

THE mining methods adopted in Japanese mines are less known to the mining world than those of other countries, owing to the geographical remoteness, but they present many features of interest to mining engineers. The Ashio copper mine is at the village of Ashio, in Tochigiken, about 109 mi. (175 km.) from Tokyo by the Imperial Government railroad. The area of the concession owned by the Furukawa Mining Co. is 5000 acres (5023 ha.). The mine was formerly divided into three, viz.. Honzan, Kotaki, and Tsudo, which are distant 3 mi. (4.8 km.) from each other as shown in Fig. 1. However, in 1914, when the writer was general manager, the three mining plants were amalgamated into one with the result of simplifying the working projects and increasing the operat-ing efficiency. The mine was visited-by the Institute party in November, 1911, when Mr. K. Inouye was the general manager. Shortly afterward, the writer was appointed manager, and, in 1915, he was succeeded by Dr. K. Asano. At the end of 1917, Mr. K. Kibe became general manager and, after two years, was succeeded by the present manager, Mr. I. Sugimoto-. For some time Dr. J. Kojima was acting general manager. It is needless to say that the gentlemen mentioned are all members of the Institute, as is also Baron T. Furukawa, president of the company. Since the discovery of the enormous masses, called "kajika" or "bullhead" deposits; which the writer has described elsewhere,&apos; the mining methods have been varied to meet the different conditions presented by these deposits.

Jan 2, 1922

By Enrique Hauser

FiRE-damp is a mixture of methane with other inert gases or combustible gases. The inert gases in question are carbonic acid, water vapor, nitrogen, etc. The combustible gases are hydrogen, ethane, etc. The study of the properties of fire-damp, therefore, becomes a study of the properties of methane and the influence on its properties of the different gases we have mentioned. Characteristic Properties of Methane 1. Respirability.—Methane being a paraffin is characterized by its weak chemical affinities. Prom the physiological point of view one could substitute it for nitrogen of the air at least momentarily, without experiencing any difficulty in breathing the mixture consisting of 21 per cent. 02 + 79 per cent. CHI. I have tried this on myself, making the gas exhaled from the lungs burn subsequently in a Bunsen burner.&apos; From the chemical point of view, this weak affinity permits the gas to be burned in certain circumstances with hydrogen and oxide of carbon in an oxygenated mixture, with the result that the last two gases achieve only a fractional combustion. This practice has been utilized with success in the methods of analysis which I have perfected and which I describe later in this paper. 2. Retardation of Flashing Point.—A characteristic property of methane is its retardation of flashing point, noted by Davy in 1816 and studied by Mallard and Le Chatelier in 1883.2 Taffanel and Le Floch have recently confirmed these results.8 Let us recall the nature of this retardation: When a mixture of combustible gases with air or with oxygen is

Jan 1, 1916

By J. D. Shaw, E. B. Gebert, D. O. Noel

It is, of course, expected that manufacture of the various metal powders should involve numerous methods adapted to the specific characteristics of the metals themselves. Several methods for powdering a particular metal may be available, but the physical characteristics of the powder as produced by the several methods may be quite different. In the final analysis, the application of the metal powder dictates the physical properties that the metal powder must possess, and this, to a very large extent, will determine which of several possible methods of manufacture is adopted. Sometimes powder of the same metal is produced by more than one method, each powder having specific characteristics that make it particularly suitable for its application. For purposes of classification, the various methods of powdering metals can be grouped as follows: 1. Machining. 2. Milling (by ball mills, stamps, attrition mills, etc.). 3. Shotting (pouring molten metal into water, air, etc.). 4. Granulation (by stirring molten metal while solidifying). 5. Atomizing (disintegrating by steam, compressed air, etc.). 6. Condensation of metal vapor. 7. Reduction of oxide powders. 8. Chemical precipitation. 9. Electrolytic deposition. 10. Sintering (for producing alloy powders). 11. Formation of an alloy followed by dissolving or otherwise removing one of the alloying constituents. Machining Turnings, cuttings, filings, etc., are, of course, produced as by-products in machine work of various kinds, and find certain applications as metal powders. For example, iron powder so produced is used extensively as a reducing or precipitating agent and as a constituent in certain hard-finish cements.

Jan 1, 1938

By D. O. Noel, E. B. Gebert, J. D. Shaw

It is, of course, expected that manufacture of the various metal powders should involve numerous methods adapted to the specific characteristics of the metals themselves. Several methods for powdering a particular metal may be available, but the physical characteristics of the powder as produced by the several methods may be quite different. In the final analysis, the application of the metal powder dictates the physical properties that the metal powder must possess, and this, to a very large extent, will determine which of several possible methods of manufacture is adopted. Sometimes powder of the same metal is produced by more than one method, each powder having specific characteristics that make it particularly suitable for its application. For purposes of classification, the various methods of powdering metals can be grouped as follows: 1. Machining. 2. Milling (by ball mills, stamps, attrition mills, etc.). 3. Shotting (pouring molten metal into water, air, etc.). 4. Granulation (by stirring molten metal while solidifying). 5. Atomizing (disintegrating by steam, compressed air, etc.). 6. Condensation of metal vapor. 7. Reduction of oxide powders. 8. Chemical precipitation. 9. Electrolytic deposition. 10. Sintering (for producing alloy powders). 11. Formation of an alloy followed by dissolving or otherwise removing one of the alloying constituents. Machining Turnings, cuttings, filings, etc., are, of course, produced as by-products in machine work of various kinds, and find certain applications as metal powders. For example, iron powder so produced is used extensively as a reducing or precipitating agent and as a constituent in certain hard-finish cements.

Jan 1, 1938

By Alden B. Greninger

That metallographic structures analogous to the martensite of steel may be found in certain copper-aluminum and copper-tin alloys has been known for many years; similar structures recently were found in certain copper-zinc a1loys.l In all three of these alloy systems the martensite structures result from transformation of the metastable fi phase when the speed of cooling from the B range is sufficiently high to suppress decomposition into equilibrium phases. In the normal decomposition of solid solutions into equilibrium phases, diffusion is needed to bring about the necessary changes in concentration, and the rate of reaction falls almost to zero at temperatures slightly above room temperature. The rates of reaction for martensite processes, however, are not dependent upon temperature; the transformation does not require rendjustments of concentration. For example, the martensite transformation in 60:40 (B) copper-zinc does not begin until the temperature has dropped to about minus 30" C., and then continues down to minus 130" C. and probably even at lower temperatures.&apos; Furthermore, martensite processes apparently proceed only while the tempcrature is falling, within the proper range, and cease completely while the temperature is held constant ;$ and they cannot be suppressed by extremely rapid cooling although the rate of cooling for some alloys may be increased to over 10,000 times the critical cooling velocity. Isaitschew, Kaminsky and Kurdjumow2 account for these observed behaviors of rnartensite processes by postulating that the mechanism 6I... consists in a regular rearrangement of the lattice in such a way

Jan 1, 1939

By Alden B. Greninger

That metallographic structures analogous to the martensite of steel may be found in certain copper-aluminum and copper-tin alloys has been known for many years; similar structures recently were found in certain copper-zinc a1loys.l In all three of these alloy systems the martensite structures result from transformation of the metastable fi phase when the speed of cooling from the B range is sufficiently high to suppress decomposition into equilibrium phases. In the normal decomposition of solid solutions into equilibrium phases, diffusion is needed to bring about the necessary changes in concentration, and the rate of reaction falls almost to zero at temperatures slightly above room temperature. The rates of reaction for martensite processes, however, are not dependent upon temperature; the transformation does not require rendjustments of concentration. For example, the martensite transformation in 60:40 (B) copper-zinc does not begin until the temperature has dropped to about minus 30" C., and then continues down to minus 130" C. and probably even at lower temperatures.&apos; Furthermore, martensite processes apparently proceed only while the tempcrature is falling, within the proper range, and cease completely while the temperature is held constant ;$ and they cannot be suppressed by extremely rapid cooling although the rate of cooling for some alloys may be increased to over 10,000 times the critical cooling velocity. Isaitschew, Kaminsky and Kurdjumow2 account for these observed behaviors of rnartensite processes by postulating that the mechanism 6I... consists in a regular rearrangement of the lattice in such a way

Jan 1, 1939

By D. O. Noel, E. B. Gebert, J. D. Shaw

IT. is, of course, expected that manufacture of the various metal powders should involve numerous methods adapted to the specific characteristics of the metals themselves. Several methods for powdering a particular metal may be available, but the physical characteristics of the powder as produced by the several methods may be quite different. In the final analysis, the application of the metal powder dictates the physical properties that the metal powder must possess, and this, to a very large extent, will determine which of several possible methods of. manufacture is adopted. Sometimes powder of the same metal is produced by more than one method, each powder having specific characteristics .that make it particularly suitable for its application. For purposes of classification, the various methods of powdering metals can be grouped as follows: 1. Machining. 2. Milling (by ball mills, stamps, attrition mills, etc.). 3. Shotting (pouring molten metal into water, air, etc.). 4. Granulation (by stirring molten metal while solidifying). 5. Atomizing (disintegrating by steam, compressed air, etc.). 6. Condensation of metal vapor. 7. Reduction of oxide powders. 8. Chemical precipitation. 9. Electrolytic deposition. 10. Sintering (for producing alloy powders). 11. Formation of an alloy followed by dissolving or otherwise removing one of the alloying constituents. MACHINING Turnings, cuttings, filings, etc., are, of course, produced as by-products in machine work of various kinds, and find certain applications as metal powders. For example, iron powder so produced is used extensively as a reducing or precipitating agent and as a constituent in certain hard-finish cements.

Jan 1, 1938