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By L. O. Howard

THE practice of using acid-lined converters at the plant of the Old Dominion Copper Mining & Smelting Co. was discontinued early in January, 1913, and they were replaced by basic-lined converters. The new equipment consists of one electrically operated 12-ft. upright converter stand and two basic-lined shells for same. These shells are provided with twenty-four 1 1/4-in. tuyères. The mouths are 5 ft. in diameter. Owing to the fact that there is no bedding system or other large storage capacity between the mine and the smelter, the furnaces must handle as fast as produced ore and concentrates, which may vary considerably from day to day, both in tonnage and copper content. Consequently the converter is often crowded to its utmost capacity by the frequent fluctuations in the daily matte supply. From the foregoing, it will be seen that in no way can the converter be favored by running light charges or by transferring to it from other stands in operation. Neither can it regularly be allowed to cool between blows, and only occasionally can it be run at as low a temperature as might be wished. No copper precipitate or other foreign material high in copper is available to help out the tonnage. Repairs and alterations or the removal of defective tuyères must wait until such time as a slight falling off in the matte supply-allows the converting operations to ease up. These variable conditions all combine to interfere with the systematic operating of the converter.

Jan 7, 1914

By R. A. Wolfe, H. W. Paxton

Self-diffilsion coefficients for cr51 and Fe55 in 12 pct Cr-Fe and 17 pct Cr-Fe for Fe55 in chromium, and for Cr51 in vanadium have been measured. The results are compared with other values for the Fe-Cr system, and with the various theories of diffusion in hcc metals. Some empirical correlations are discussed between Do and Q in hcc systems, or, expressed differently, the constancy of ?G*/T solidus for seveval bcc metals and alloys is noted. It appears very probable that a vacancy mechanism is operative in bcc metals, hut this cannot he stated with certainty. THE great bulk of work on diffusion in metals, both experimental and theoretical, was for many years concentrated on those with close-packed and, in particular, fcc lattices.1,2 There appears to be little doubt that the mechanism of diffusion in these solids is vacancy migration, leading to mass transfer and in substitutional solid solutions to a Kirken-dall effect.3,4 For bcc metals, the picture is much less clear. The Kirkendall effect certainly occurs in several alloys.5-10 However, attempts to understand the factors contributing to the pre-exponential in the usual expression for the diffusion coefficient D =D, exp {-Q/RT) by extension of ideas useful in close-packed lattices have not always been successful. Zener,11 Leclaire,12 and Pound, Paxton, and Bitlerl3 have suggested that various forms of ring diffusion may be important in some bcc metals. For close-packed metals, Do is usually about 1 sq cm per sec and Q - 35Tm kcal per mole (Tm = melting temperature in OK). The theory of Pound et al. suggests for ring diffusion that Do may be about 10-4 and Q, although difficult to calculate with any precision, would be significantly less than 35 T,. The experimental results on self and solute diffusion in ? uranium14,15 and ß zirconium,10 and for solutes in 0 titanium,17 and possibly for self-diffu- sion in chromium below about 0.75 T,," gave some credence to this theory. However, not all bcc materials display low values of DO and Q, and the exceptions were not predicted by any theory. Furthermore, it has recently become apparent that, in bcc materials, log D is not always linear with T-l if a sufficiently wide range of temperature is studied.16,18 This variation may be such that Q may increase18,19 or decrease20 with increasing temperature. The present work was undertaken in an attempt to provide further diffusion data on bcc metals, and to try to understand the factors which contribute to differences in behavior between the various elements. For part of this work, the Fe-Cr system was chosen since it is of considerable technological importance, and data on 12 pct Cr and 17 pct Cr alloys appeared well worthwhile to supplement that existing for the remainder of the stern.18,22 The diffusion of Fe55 in chromium was studied as an example of a more or less "normal" tracer element in a possibly abnormal host lattice. Finally, no data were available for vanadium, the neighbor of chromium in the periodic table, because of lack of a suitable isotope so cr55 was used as a tracer in a few preliminary experiments. For convenience, we shall refer to elements whose Do and Q are low compared to those predicted by Zener's theory as "anomalous". PROCEDURE This investigation determined self-diffusion rates by means of radioactive tracers and the integral-activity method first utilized by Gruzin.23 In this method a thin layer of radioisotope of the diffusing element is plated or coated onto a planar surface of the diffusion sample, which is then given an isothermal-diffusion annealing treatment. The determination of an activity-penetration curve involves measuring the residual activity of the specimen after each successive layer or section has been removed parallel to the original planar surface. The method used here is essentially the same as that used by Gondolf18 and Kunitake.21 Two radioactive tracers, cr51 and Fe55, were used in this investigation. Diffusion coefficients were determined for the diffusion of one or both of these tracers in four different materials, viz., Fe-12 wt pct Cr alloy, Fe-17 wt pct Cr alloy, chromium, and vanadium. The diffusion samples had nominal dimensions of 1.5 cm diameter and 0.5 cm thickness. The grain size was several millimeters for the Fe-Cr alloys and at least 1 mm for the chromium and vanadium samples. Accurately planar surfaces

Jan 1, 1964

By D. W. Fuerstenau

In recent years, various advances have taken place in the flotation recovery of fine mineral particles. A number of new approaches to recovery of fine particles have been proposed. In this paper, the background and performance of some of these tech- niques for fine particles processing are reviewed. A brief sum mary of the problems associated with fine particles in flotation and related processes is presented.

Jan 1, 1980

By H. L. Luo

SYSTEMATIC investigations of the Fe-Ga system have been reported only very recently."' The maximum solid solubility of gallium in a-Fe is nearly 50 at. pet at 900°C. However, from Ref. 1, it was not evident that the a-Fe solid solution could be retained successfully beyond 17.38 at. pet Ga by solid-state quenching. The present investigation reports the retention of a-Fe solid solution at 50 at. pet Ga by quenching from the liquid. An ordered phase of CsC1-type B2) structure was observed between 34 - 50 at. pet Ga. Since it was considered very probable that the CsCl structure would occur at high temperatures, alloy filings were also quenched by the conventional quenching technique. In addition to the CsCl phase, a second ordered phase of BiF3-type (DO3) structure was found in the range 25 - 30 at. pet Ga. Alloys were prepared from elements of 99.99 pet purity or better, induction-melted in alumina crucibles under hydrogen. After reweighing, the alloy ingots were cast into wires under argon. From the weight losses and the reproducibility of the lattice parameters, compositions were estimated to be within ± 0.3 at. pet. The techniques of quenching from the liquid state were reported before.3-5 Prior to quenching, a small section of cast alloy wire (30 - 50 mg) was melted in an alumina insert under an argon flow. The quenched specimens were in the form of flakes, typically 1 sq mm in area. For solid-state quenching, alloy filings passing 200 mesh were sealed under a reduced helium atmosphere in a thin-bottom silica tube. After heating for -30 min at the desired temperature in a vertical furnace, the sealed tube was rapidly dropped into ice water so that the thin bottom of the tube broke on impact. The quenched alloy filings were always ferromagnetic and could be collected by a magnet. X-ray diffraction patterns were taken with iron-filtered cobalt radiation in a 114.6-mm-diam Debye-Scherrer camera. High-angle lines were always resolved and spacings were computed relative to ? (CoKa1) = 1.78890Å. Lattice parameters were obtained from extrapolation against the Nelson-Riley function. The variation of lattice parameter with composition is shown in Fig. 1, together with the data of Dasarathy and Hume-Rothery.1 Uncertainties in the present measurements are within the dimensions of the symbols or indicated by error bars. X-ray diffraction lines indicative of CsC1-type ordering could be clearly identified for alloys of 34 - 50 at. pet Ga quenched from the liquid and alloys of 35 - 41 at. pet Ga quenched from -975°C. Within experimental error, no difference in

Jan 1, 1968

Executive A. R. LEDOUX, Chairman GEORGE D. BARRON SIDNEY J. JENNINGS J. V. N. DORR J. E. JOHNSON, JR.¬ Membership J. E. JOHNSON, JR., Chairman KARL EILERS F. F. SHARPLESS R. M. RAYMOND LEWIS W. FRANCIS Finance J. V. N. DORR, Chairman CHARLES F. RAND J. V. W. REYNDERS Library E. GYBBON SPILSBURY,' Chairman ALEXANDER C. HUMPHREYS GEORGE C. STONE' JOHN H. JANEWAY BRADLEY STOUGHTON Papers and Publications BRADLEY STOUGHTON, Chairman

Jan 1, 1923

Jan 1, 1934

By Alexander Knoll, Dwight L. Baker

THE work herein reported shows that galena in certain organic solutions of fatty acids becomes coated with lead soaps, and that this coating is not only highly water-repellent but is also repellent to certain organic liquids, particularly those [ ] of high surface tension; i.e., nitrobenzene, diphenylmethane. WETTING PROPERTIES OF GALENA IN NONAQUEOUS FATTY ACID SOLUTIONS When a "captive bubble"1 is withdrawn from a polished, plane galena surface under a nitrobenzene solution of stearic acid, the air bubble shows a decided tendency to "cling" to the mineral surface. The contact angle, therefore, was greater than zero, although it was not large enough to be measured quantitatively by the captive-bubble method.* [ ] When pure nitrobenzene' was substituted for the nitrobenzene-stearic acid solution, no clinging of the bubble was observed; viz., contact angle = zero. Although the contact angle developed in air-galena-nitrobenzene-fatty acid solution was small, the organic solvent repellency of the galena surface was great enough to enable good recovery in a laboratory flotation cell.2 In Table I are given the results of flotation experiments using several different fatty acids dissolved in nitrobenzene.

Jan 1, 1941

By Robert E. Green, Wolfgang Sachse

Simullaneous ultrasonic attenuation measurements of both quasishear waves propagating in single cryslals of aluminum indicate that, in the undeformed annealed state, the dislocation density is generally not uniform on all slip systems. Change oof attenuation measurements made during plastic defortnation of crystals , which possessed specific orientations ideal for studying the orientation dependence of dislocation damping, indicate that, for low strain levels, dislocation motion occurs on additional slip systems besides the primary one, even for crystals oriented for plastic deformation by single slip. THE sensitivity of internal friction measurements permits such measurements to be used successfully in studying the deformation characteristics of metal crystals. On the basis of experimental observations, T. A. Read1 was the first to associate internal friction losses with various dislocation mechanisms. Since that time further work2-' has been performed and a dislocation damping theory has been formulated by Granato and Lucke.6 In the amplitude independent region, this theory predicts the attenuation a to be dependent on an orientation factor O, a dislocation density A, and an average loop length L. if is a constant, independent of crystallographic orientation. For a given crystallographic orientation, changes in dislocation density and loop length give rise to the observed attenuation changes accompanying plastic deformation. The Granato-Liicke theory suggests the investigation of the orientation dependence of attenuation measurements in hopes of obtaining information to separate dislocation motion losses from other losses.7 An experimental study of the orientation dependence of attenuation in undeformed annealed single crystals should yield an insight into the uniformity of dislocation distribution throughout the entire specimen. A similar study on crystals plastically deformed in a prescribed fashion should give information about the alterations in the dislocation distribution on the slip systems activated during plastic deformation. The possible modes of elastic waves which can be propagated in aluminum,8 copper,9 zinc,10 and other hexagonal metals" have been calculated. Associated with each mode of wave propagation are dislocation damping orientation factors, which are based on the resolution of the stress field of that particular elastic wave onto the various operative slip systems in the material. These orientation factors have also been calculated as a function of crystallographic orientation in the papers cited above. Einspruch12 obtained agreement between predicted and observed attenuation values of longitudinal and shear waves in (100) and (110) directions of two undeformed aluminum crystal cubes. He ascribed the slight deviations between predicted and observed values to a nonuniform dislocation distribution, or to other loss mechanisms. In shear deformation of zinc crystals, Alers2 found that the attenuation of shear waves having their particle displacements in the slip plane was very sensitive to the deformation, while the longitudinal wave attenuation was affected only when the wave propagation direction was not normal to the slip plane. Using aluminum single crystals oriented for single slip, Hikata3 et al. found that during tensile deformation the change of attenuation of the shear wave (actually quasishear) having particle displacements nearly perpendicular to the primary slip direction exhibited the easy-glide phenomena, while longitudinal waves did not. Similar results were reported by Swanson and Green5 during compressive deformation of aluminum crystals. These results are in qualitative agreement with the calculated orientation factors for specimens of this orientation. In well-annealed, undeformed aluminum crystals, the damping is expected to be due to dislocations vibrating on all twelve slip systems. The orientation factors associated with this initial damping will be designated by O2 and O3, where a, represents the average orientation factor for the slow shear (or quasishear) wave and O3 represents the average orientation factor for the fast shear (or quasishear) wave. The calculation of these values for aluminum crystals by Hinton and Green8 shows that they vary very little as a function of crystallographic orientation—at most, by a factor of 2.47. If the dislocation density and loop length are uniform, then in the initial undeformed state, Here the subscript zero refers to the initial value of the attenuation. Also for aluminum, the calculations8 show that the orientation factors for primary slip only, associated with each shear wave, exhibit a sharp minimum for particular crystallographic orientations. A composite plot of the two shear wave orientation factors for primary slip only is shown in Fig. 1. Since these orientation factors are associated with dislocation motion occurring on the primary slip system only, the proper condition to check these factors might be attained by slightly deforming a single crystal oriented for primary slip. For dislocation motion on the primary slip system only,

Jan 1, 1969

By Richard F. Miller, W. E. Milligan

Work was undertaken two years ago at the Hammond Laboratory for the purpose of determining the magnitude of the elastic range in single crystals of pure metals by means of creep tests, the assumption being made that if a true elastic range exists, the elastic limit represents the maximum stress for no creep. A sensitive extensometer was constructed, and creep tests were made on zinc single crystals at a variety of loads and temperatures1. It was soon discovered that there is no measurable elastic limit in ductile zinc single crystals at, or above, room temperature. The inference that pure metallic single crystals may not possess a definite elastic range was not justified, however, since zinc had been tested in creep only above its recrystallization temperature, and several investigator2,3,4 had already shown that above the recrystallization temperature polycrystalline metals will flow under very small stresses, while below that temperature stresses of a much larger magnitude are required. For that reason, it was decided to extend the study of the elastic limit to other metals having a higher recrystallization temperature than zinc. Aluminum and silver were selected, because of the ease of obtaining pure materials and of preparing large single crystals, and because the crystallo-graphic glide system of these metals is well known. Owing to the limited time available, the elastic range was investigated by slow tensile tests rather than by creep tests. Production of Specimens A luminum Recrystallized single crystals were prepared from 99.95 per cent aluminum supplied by the Aluminum Company of America. The ingots were melted in an Acheson graphite crucible in a gas furnace, and cast

Jan 1, 1937

By William E. Ford, Edward Salisbury Dana

The Silicates are m part strictly anhydrous, in part hydrous, as the zeolites and the amorphous clays, etc. Furthermore, a large number of the silicates yield more or less water upon ignition, and in many cases it is known that they are, therefore, to be regarded as basic (or acid) silicates. The line, however, between the strictly anhydrous and hydrous silicates cannot be sharply drawn, since with many species which yield water upon ignition the part played by the elements forming the water is as yet uncertain. Furthermore, in the cases of several groups, the strict arrangement must be deviated from, since the relation of the species is best exhibited by introducing the related hydrous species immediately after the others. This chapter closes with a section including the Titanates, Silico-titanates, Titano-niobates, etc., which connect the Silicates with the Niobates and Tantalates. Some Titanates have already been included among the Oxides.

Jan 1, 1922

By Günter Petzow, Siegfried Steeb

DURING an investigation of the U-Co-A1, U-Ir-A1, and U-Ni-A1 ternary systems, three previously unknown phases have been identified which correspond to the phases UCoA1, UIrA1, and UNiA1, and which be- long to the C22 (Fe2P) type (P 6 2m). In the following the structure determination of the new ternary phases is reported. The alloys have been prepared in an arc furnace under purified argon from 99.97 wt pct U, 99.83 wt pct Co, 99.99 wt pct Al, 99.95 wt pct Ni, and 99.97 wt pct Ir. The pellets obtained were bright and brittle; chemical analyses agreed with the nominal compositions. To obtain equilibrium, the samples were annealed in evacuated quartz capsules at 950°C for 30 hr and then quenched in water. Guinier photographs were processed and evaluated according to a method already described previously.1,2 The hkl's, measured and calculated sin2 6 values, and in the case of UCoAl only calculated and estimated intensities, are given in Tables I to 111. Lattice parameters refined according to the least-squares method and the respective mean-square variations are presented in Table IV. Lattice parameters, especially the c/a ratio, lead to the assumption that the three phases are crystallizing in the C22-type structure. For the calculation of the intensities given in Table I, the atomic positions recently reported by wyckoff3 have been accepted for the C22 (Fe2P) type. The uranium atoms were assumed to be in phosphorus sites; furthermore the scattering amplitudes of the boron atoms have been averaged in the stoichiometric formula UB2 according to atomic percentages; i.e., for these atoms a statistical distribution on the iron sites was assumed. The two smallest distances between a uranium and

Jan 1, 1967

By Eric R. Jette, A. G. H. Anderson

A few years ago, while the writers worked on the constitution of ternary and quaternary alloys consisting mainly of iron, chromium and siliconl,2 some information on microstructures and hardness, not incorporated in the published work, alas obtained. It has not been possible to do any further work on the properties of the alloys. The information possessed is hereby presented for the interest it may have in connection with the constitution of the alloys. Microstructures Referring to the iron-chromium-silicon diagram,' the regions that received most attention were those in which the sigma phase appears. It was found that the mode of occurrence of this phase varied much with the condition under which it mas formed, and the mode influenced considerably the hardness of the alloys. In some slowly cooled alloys, well within the alpha + sigma-phase boundary, sigma occurs in pabterns suggesting a eutectic. The structure of such an alloy is shorn in Fig. 1, showing it to be partly coarsely laminated and partly globular mottled. In other annealed and slowly cooled alloys, the lanlinated structure is entirely absent, and sigma appears in an irregular distribution of sharply cornered elongated areas (Figs. 2 and 3). These areas all possess a more or less mottled structure. A carbide phase is also visible in these two photomicrographs; it is represented by bright white arras of various shapes, sometimes apparently enveloping the sigma. Quenched and aged specimens, whose compositions arc: located near the phase boundary between alpha and sigma + alpha regions, have structures not unlike martensite (Figs. 5 and 6). Fig. 4 shows the structurc of alloy No. 35 as quenched from 1100" C.; it is a typical solid solu-

Jan 1, 1938

By L. W. Page

PrEvious to the introduction of the motor vehicle the broken stone or macadam' road met the conditions of rural horse-drawn traffic better than any other type of road, but under fast motor traffic it has been proved to be quite unsatisfactory, and necessitates high maintenance charges. Such a road depends for its success upon the fact that the rock dust fills the voids between the stones and acts as a cement or binder. Under ideal conditions it should be constructed of rock so suited to the volume and character of horse traffic that only enough fine dust is worn from the stones of which the road is composed to take the place of that carried off by wind and rain; and when these conditions are met, the fine dust resulting from the wear of traffic forms with the stone a smooth, impervious shell, shedding the surface water and protecting the foundation. With increase in the number and speed of motor vehicles, however, it was soon found that the cost of maintenance also increased, until at the present day highway engineers consider the old method of constructing and maintaining broken-stone roads increasingly inadequate, and are introducing every known type of binding material other than rock dust to cement the stone together. Among the most prominent types of products in use are those produced from our various petroleums. That the value of modern methods of road preservation was appreciated in this country much earlier than we have been accustomed to believe is demonstrated by the recent revival of an old patent which was granted to one John Martineau, of Elbridge, N. Y., in 1834. Petroleum had, of course, not been discovered at that time, but he claims as his invention and improvement "The application of tar, turpentine, or any of that class of tenacious, cohesive substances, reduced before use to a fluid state, and that state used as a cement, to apply to, and combine with sand, gravel, pebbles, and pulverized stone, such as is used for a Mc-Adam road, or cobble stone, the interstices of coarser material being in all cases filled,'as well as may be, with sand and gravel and cemented with tar or turpentine, to form the wearing face or surface of streets,

Jan 1, 1915

Shovel To further increase the efficiency in the production of their foundry sand, the American Silica Sand Co. has purchased a new and improved shovel that will be used for loading trucks at their Reynolds Pit. The [ ] new shovel will greatly facilitate winter mining operations and make possible larger winter shipments of the company's foundry sand. The Reynolds Pit is one of three sand pits in the Ottawa district owned by American Silica which produce sand that is refined for foundry use. Circle No. 1 Electric Switches The Crane Electric Co. has just announced the production of their R-1000, a new rotating limit switch designed to control the travel of any rotating device requiring interruption or establishment of electrical current after a predetermined number of revolutions. It is useful for machinery, lifts, and other power equipment. The switch is presented in a finished case, 16 gage, reinforced, with walls of sufficient strength to hold the entire mechanism and all the parts in accurate alignment. The worm gear combination has a 60 to 1 ratio, sufficient for most industrial uses. The number of revolutions can still be increased by using various combinations of driving sprockets, either on the shaft of the switch, or on the sprocket of the unit controlled by the switch itself. Circle No. 2

Jan 1, 1952

• As part of $850,000 granted by the House Appropriations Committee for development of manganese in the U.S., the Bureau of Mines will build a pilot plant at Artillery Peak, Ariz., for development of low grade manganese ores. • The historic Argo tunnel and mill in Idaho Springs, Colo., will reopen shortly for the mining of uranium. The Uranium Co. of America has acquired control of the tunnel and mill and 12 nearby mining properties. J. H. Rodgers and G. C. Ridland will manage the operation. •The opening of a new 4000-ton per day coal mine in Washington Co., Pa., and the reopening of another mine of the same capacity in Fayette Co. has been announced by the H. C. Frick Coke Co. They'll help meet added war demands. •A 7000 bbl per day commercial synthetic liquid fuel plant, making gasoline from natural gas at Brownsville, Texas is being operated by the Carthage Hydro-col Corp., a Texaco subsidiary. The gasoline is produced by the Hydrocol process, chemically similar to the Fischer Tropsch process, but differing mechanically in several ways. To operate the process it has been necessary to build an oxygen plant producing 95 pct pure oxygen in quantities equal to U. S. production of commercial oxygen in 1946. •Over 96 pct of the class of 1950 at Montana School of Mines are now employed,, in industry, and they're scattered from MIT to the island of Cuba., • Cobalt, heretofore almost entirely imported, will soon be produced in Idaho. The Calera Mining Co. is building a 600-ton mill in which a cobalt and copper concentrate will be obtained from Idaho ores. •Plans for mining iron ore on the Conarky Peninsula in French Guinea, (an ECA project) call for equipment purchases as follows: 8 wagon drills, electric shovel for mining, conveyor for the port, 8 trucks, wrecker, 2 tractors, as well as miscellaneous accessories and spare parts. •A low-grade lead-zinc mineralization, located east of any known ore bodies in Utah's East Tintic district, has been located by a 2000-ft wildcat USGS drill hole. * Higher-than-going rates have been authorized by the Munitions Board for its stockpile program, where domestic production of scarce materials is low or uneconomical. Payment in excess of 25 pct over the foreign price is now permitted. •A new self-centering conveyor roll, developed by Carnegie-Illinois Steel, is expected to revolutionize materials handling. It completely eliminates the necessity for sideguides to keep materials on a conveyor. See P. 1028. •Great Britain's socialized coal industry employs twice as many miners, but produces less than half as much coal as America's coal industry. last year, British mines produced 28 million fewer tons of coal than the output of the same ,mines in 1939. Absenteeism amounted to a big 12 pot of working time. • Labor market conditions have tightened on almost a country-wide scale. Only 4 out of 143 major labor market areas have a substantial surplus -- less than half the total for May. Growing scarcities of skilled labor are in evidence.

Jan 10, 1950

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons. ) An experienced gold and silver metallurgist specializing in cyaniding is desirous of obtaining a position in 'America. Speaks, Mexican Spanish fluently. A member, a. technical graduate, with four years' experience in railroad work and-general construction, two years' on mine examination and geological reconnaissance, and two a half years' drilling exploration in placer work and petroleum, together with prospecting and geological interpolation, desires a position as a mining engineer or mining geologist. An experienced mine superintendent, manager, or field engineer, is open for engagement. He has had 12 years' experience as superintendent and manager of large mines in the United States and Mexico, and experience in mine examination. A member of the Institute with several years' experience in mining in the Lake Superior copper district, is open for engagement.

Jan 7, 1913

By A. E. Jenkins, O. C. Roberts, D. G. C. Robertson

Using an inverted-cone coil at 450 kHz, it has been possible to levitate iron (FeS), cobalt (CoS), and nickel (NiS) sulfides. Important nontransition metal sulfides such as ZnS, PbS, and Cu2S have proven impossible to levitate although Cu-Fe-S ternary alloys containing 30 wt pct S and up to 10 wt pct Cu, and Cu-Co-S and Cu-Ni-S ternary alloys containing 30 wt pct Cu have been levitated. The levitation technique has been used in preliminary experiments on the vaporization from liquid sulfides and the reaction of liquid metal-sulfur alloys with oxidizing atmospheres. The course of the reactions with pure oxygen were followed using highspeed photography and two-color pyrometry. ELECTROMAGNETIC levitation is now established as a basic laboratory technique in high-temperature research but its application has been restricted mainly to metals and alloys. Applications have included alloy preparation,' metal purification,2'3 determination of liquid metal densities and emissivities,4,5 and studies of metal supercooling,4 alloy thermodynamics,6 and vaporization phenomena.7-9 The application of the technique to compounds has not been considered previously. The successful investigation of the reactions between dilute iron alloys and oxidizing atmospheres10'1 has prompted the current physico-chemical studies involving levitated metal sulfide drops and flowing inert or oxidizing atmospheres. This paper presents the results of such a study and provides a basis for future studies involving a wide range of other compounds of metallurgical interest. The successful levitation of many metal sulfides and mattes provides a method of studying the oxidation reactions fundamental to flash-smelting and similar pyrometallurgi-cal operations under closely controlled laboratory conditions. In addition the system allows the use of a controlled atmosphere (e.g., a gas stream of a certain H2/H2S ratio) with a particular chemical potential to study the relevant thermodynamic equilibria or the mass transfer processes between the atmosphere and the levitated drop under conditions where the hydrodynamics of the system can be closely defined. The optimum frequency for the levitation melting of metals in an inverted-cone coil type inductor is within the radio frequency range 400 to 500 kHz. At frequencies lower than 10 kHz the rate of heat generation is usually insufficient to melt the levitated charge' or where melting is achieved, "dripping" from the charge is encountered.'' At frequencies above 2 mHz the levitation force decreases. Metals, alloys and preheated elemental semiconductors such as germanium and silicon, have been levitated but the levitation of only a few metal compounds has been reported. Jostsons13 and the authors have levitated liquid titanium-oxygen alloys containing 50 at. pct 0 while clark14 has reported the levitation of mixtures of FeS and MnS for short periods. With a "cold crucible" inductor sterling15 has melted ferrites by preheating them by induction in a 4 mHz field and melting at a lower frequency. However this second type of inductor has been designed purely for the melting of materials without contamination; there is only a small gas film between the charge and the inductor and the electromagnetic levitation effect is of secondary importance. For this reason further discussion will be restricted to the use of the coil type inductor. The assessment of the suitability of a particular metal compound for levitation is based upon the following two criteria: i) thermal stability, and ii) physical "levitability". In this paper these two criteria will be considered separately. The thermal stability of a solid or liquid metal compound with respect to a gaseous environment depends upon its chemical reactivity with that environment or, in the case of an inert atmosphere considered here, its volatility. The physical criterion as to whether or not a particular compound can be levitated is based upon a comparison between those physical properties of the compound determining "levitability" which are defined by the fundamental equations of levitation theory as developed by Okress et a1.,16 and the properties of the metals. Since it is not practical to cover the vast field of metal compounds, further discussion will concentrate on the metal sulfides but the treatment would be applicable to any metal compound. THE THERMAL STABILITY OF METAL SULFIDES The temperatures usually encountered during levitation in inert atmospheres cover the range 1400" to 2000°C. The stabilities of the condensed states of the sulfides under these conditions are considered in relation to the periodic classification by reference to Table I. Two general classes of sulfides emerge. The solid sulfides of elements of group IIB and of groups further to the right are volatile while those sulfides of group IB and of groups further to the left are nonvolatile solids. The sulfides described as volatile may be dismissed as unsuitable for levitation. The stabilities of the more favorable nonvolatile sulfides under the anticipated conditions must be studied more closely From Table I it is seen that the alkali metal sulfides exist as liquids in the temperature range of in-

Jan 1, 1970

By Alexandre Pourcel

The perusal of Mr. Willard P. Ward's " Notes on the Behavior of Manganese to Carbon," presented at the Washington meeting of the Institute in February, 1882, has suggested further reflections on the same general topic, and has led to the preparation of the present paper. The same observation that Mr. Ward has put on record in his "Notes" was also made by myself at about the same time (in August, 1875), and under almost the same conditions. From a blast-furnace that was very hot, as was the furnace mentioned by Mr. Ward, I obtained a pig-iron containing about fifteen per cent. of manganese, gray in color, and very tough. It could be pulverized, but could not be cut with the chisel. I analyzed this iron and found that it contained, as I had suspected,a large amount of silicon. From this fact I drew the conclusion that the silicon had deprived the manganese of its power of dissolving carbon, since the latter, instead of occurring in the pig in combillation, appeared as graphitic carbon. I thus saw reproduced on a large scale, and demonstrated in a visible way, the property that Colonel Caron, a French scientist, had discovered in silicon,—the property of obstructing the process of hardening in steels by keeping the carbon in the graphitic condition. An attentive study of the conditions under which the phenomenon observed by Mr. Ward takes place led me to go back to operations of synthesis, and to make as I wanted them pig-irons containing varying quantities of silicon, manganese, and carbon. An iron, thus prepared, was intended to serve me as a chemical reagent in the production of steels cast without blow-holes, such as my lamented friend, Mr. A. L. Holley, has introduced and made known to the United States. What I needed in order to make very soft steels, cast without blow-holes, was an iron which, when it was added to the bath of steel, introduced into the bath a sufficient amount of silicon and of

Jan 1, 1883

By T. S. Hutchinson, C. E. Kemp

The bottom water drive analysis presented by Muskat has been extended to include fields with wider well spacings. Curves are presented from which volumetric sweepout, water-oil ratio, and rate relations may be calculated. The effects of non-unity ratios on sweepout eficiency and productivity decline have been studied by an approximate method. Also, the effect of gravity on volumetric sweepout has been approximated for a particurlar geometry. INTRODUCTION The purpose of this paper is to report work done in applying the analysis of bottom water drive reservoirs given by Muskat1 to a larger class of reservoirs, to extend this analysis to include the effects of gravity and non-unity mobility ratios in an approximate manner, and to investigate the rate of decline of productive capacity. The bottom water drive type reservoir is one where the oil is underlain by a water zone of sufficient thickness that water movement is essentially vertical. This system is defined in more detail in the appendix and a one well element is shown diagrammatically in Fig. 1. Muskat obtained solutions to the equations describing the volumetric displacement efficiency of idealized bottom water drive systems by assuming that gravity effects due to differences in density betwecn oil and water were negligible and that the mobilities of oil and water were the same. If either of these assumptions is not made, the complexity of the system makes an analytical solution well nigh impossible at the present stage of mathematical development. Coles and Stade' developed an approximation to consider these factors. The authors have refined approximations, starting with the same basic assumption, which should give a somewhat quantitative picture of bottom water drive performance when mobilities are not equal and the effects of gravity are not negligible. The results of these approximate calculations can then be used to obtain the decline in well productivity as the field is depleted.

Jan 1, 1957

By E. H. Dix

The success of the Charpy impact test in the steel industry has led those interested in aluminum alloys to investigate the possible application of this test to aluminum and its alloys. In this paper are set forth the results of a few preliminary tests made at the Lynite Laboratories of the Aluminum Manufactures, Inc. In order to study more thoroughly the significance of the Charpy test, slow-bending tests have been made duplicating the arrangement of the impact machine. Tests have been made on both notched and unnotched specimens of a series of copper-aluminum alloys. Apparatus The standard American-made Charpy impact machine delivering a blow of over 200 ft.-lb. was much too large to test aluminum-alloy specimens of the same type used for steel, so that it was necessary either to adopt a larger specimen or to have a special light-weight hammer made. Since there is no known relation between specimens of different sixes, even though geometrically similar, it was decided to adhere to the 10 by 10 mm. specimen. Accordingly, Sauveur and Boylston, the American makers of the machine, were asked to construct a special light-weight pendulum adapted to their standard machine, this pendulum to have one-tenth the capacity of the standard. The writer wishes here to acknowledge his indebtedness to Mr. H. M. Boylston for the personal interest and care exercised in constructing this pendulum. The machine with the light-weight hammer in place is shown in Fig. I. It is mounted on a concrete foundation with the concrete covering the flange on the base of the machine. Vibration is further prevented by four 5/8-in. (15.8 mm.) foundation bolts. The large standard hammer shown against the wall was also used for some of the unnotched bars that required more than 20 ft.-lb. to rupture. When the light-weight hammer was received, it was carefully cali-

Jan 1, 1921