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By K. Mukai, M. Ishihara

This report is a brief discussion of the impurity levels both in primary aluminum and super-purily alnminim in connection with raw materials and proc-essing methods. Particularly, truce amounls of im-purities were analyzed by introducing nittss-speclro-gruphy and nenlron-aclivalian analysis techniques. Vanadium and gallium content in primary aluminum metal corresponded to theor amounls in anode coke. but the nickel content in primary aluminum was hide-pendent oj its amount in the anode cake. Sulfur in the anode colic might result in an increase of the iron content in the molten metal in the reduction cell. The content of sodium and calcium increased with increasing bath ratio. In the holding furnacc sodium content decreased rapidly, and nonmetallic inclusions merit separated front the mollen metal. Three-layer elctrolysis was effectire in eliminating many impuri-ties with the exception of copper, aluminum oxide. aluminum nitride, and some rare-earth elements. THE amount of impurities and nonmetallic inclusions in aluminum metal depends on impurities in the raw materials and various production processes. This paper presents an investigation of the behavior of impurities and nonmetallic inclusions in aluminum during the electrolysis process, the period in the holding furnace, and the process of three-layer electrolysis. Chemical analysis and emission spectrometric analysis have generally been used as methods to determine small amounts of impurities in both primary aluminum and super-purity aluminum; however. mass spectrography and neutron-activation analysis have been recently introduced into this field, and trace amounts of impurities can accurately be determined by these latter methods. EXPERIMENTAL WORK Common impurities were determined by means of absorptiometric. polarographic, flame-photometric. and emission-spectrometric methods. However, in the determination of trace amounts of impurities and non-metallic inclusions, the following methods were applied. In the analyses of trace impurities by mass-spec- trographic analysis, samples were exposed in the vacuum spark of double-focus ing Mattauch-Herzog type mass spectrograph (Japan Electron Optics Laboratory, Ltd.). Ilford Q2 photographic plates were used as ion detectors. Fe was used as the internal standard, and the atomic concentration of each element was calculated by the following expression and converted into the weight concentration: where E, and Ei are the exposures (coulomb) when isotopes of the internal standard and impurity elements (on which the estimate is based) show the same density, X is the percent (atomic) concentration of the standard, IF and Ii are the percent abundances of the isotopes of the standard the impurity elements (on which the estimate is based), and Ms and hfi are the mass of the isotopes of the standard and impurity elements (on which the estimate is based). The coefficient of variation in this method is about 40 pct in the range of 0.1 to 1 ppm. In neutron-activation analysis, irradiations were done in the nuclear reactors TRIGA-I1 (neutron flux: 4.7 x 10 11 n per sq cm per sec; Rikkyo University) or JRR-2 (neutron flux: 2 x 1013 n per sq cm per sec: Japan Atomic Energy Research Institute). After the chemical separation, a NaI (3 by 3 in.) scintillator connected to a 256-channel y-ray spectrometer (R.C.L.) was used for counting and recording various activated impurities. The coefficient of variation in this method is about 20 pct. In the analyses of nonmetallic inclusions, aluminum-oxide determination was carried out according to Fischer's method, 3 as follows. A slice of sample was cut off and the surface was cleaned. It was dissolved in bromine-methanol. The solution was filtered and the residue was washed. The residue was fused with potassium bisulfate flux. Then it was dissolved in weak acid, and oxine solution was added. The aluminum oxinate was extracted with benzene. Finally, aluminum was determined absorptio-metrically. Aluminum nitride determination was carried out as follows. A slice of sample was cut off and the surface was cleaned. It was put in the distillation apparatus and decomposed with sodium hydroxide solution. The solution was distilled. Then ammonia was absorbed and

Jan 1, 1967

By Frank Alfred Fahrenwald

MetallURgical research has discovered many an alloy possessing properties not combined in any single metal, and progress still consists chiefly in the investigation and utilization of alloys. In the case of iron, the demands of automobiles, high-speed machines and high-duty engines have led to the production of special iron alloys which will meet any reasonable specifications in that field. In like manner, the bronzes, brasses and other alloys of copper have been brought to remarkable perfection, and for nearly every industrial purpose some alloy has been , found more suitable than the pure metal. Less complete success has attended the attempt to find substitutes for gold, platinum, and the other precious metals. Indeed, it is not likeiy that a material can be produced which, will possess all the properties of any one of them; yet it is reasonable to hope that, for any given use, the properties required may be found in some less expensive material. Thus, in incandescent electric lamps, the wire passing through the thick glass neck of the bulb was, until recently, almost universally made of platinum, for the single reason that no other known material, suitable as a conductor, had the same coefficient of expansion as glass. But a comparatively recent investigation of the iron-nickel series1 has shown that alloys of those metals maybe produced, the coefficient of expansion of which can be accurately controlled between that of iron or nickel and zero. Thus, in that particular industry, a substitute for platinum has been found. According to statistical reports, not only considerable quantities of gold and iridium, but also more than one-third of the annual supply of platinum, are used (and, in the nature of the case, irrevocably lost) by dentists. Platinum is thus employed in several forms. As a thin foil, it serves various purposes for which its high melting point, pliability, chemical resistance, and other properties—including the ease with which it may be soldered—are invaluable. But it is most extensively used in

Jan 1, 1916

By R. D. Reiswig, J. M. Dickinson

The 0s-Ir equilibrium diagram was determined. The diagram is of the simple peritectic type, with a peritectic temperature of about 2660°C. The solid miscibility gap is narrower than previously reported, the nearly vertical solvus lines occurring at about 42 and 63 wt pct 0s. Widmanstaetten figures resembling martensite in some of the two-phase alloys account for a previously suspected transformation. In view of the long history of use of such alloys, it is surprising that the 0s-Ir equilibrium diagram has not yet been completely determined. The boundaries of the miscibility gap in this system have been estimated to be between 24 and 39 wt pct 0s and 79 and 100 wt pct OS. It has been predicted3 that alloys of ruthenium, osmium, and rhenium with the fcc platinum metals should solidify peritectically in their two-phase regions. The metallographic examination of natural osmiridium alloys has been said4 to indicate, by the presence of a martensitic structure, the existence of a transformation or a phase separation. On the basis of superconducting transition temperature measurements, a 70 at. pct 0s alloy was found5 to be two-phase prior to annealing. EXPERIMENTAL The elemental components used in this work were obtained from several suppliers as sponge. The purities, stated by each supplier to be in excess of 99.8 pct, were confirmed in each case by a semiquantitative spectrographic analysis. The pure components were premelted in an inert-gas tungsten arc furnace with the evolution of some fume, crushed, and pickled for use as alloy melting stock. Upon arc melting to the final compositions, no fume evolution was observed. Because weight losses of the order of 15 mg or less were observed in preparing alloy buttons weighing 15 g, "synthetic analyses" were used in determining the compositions of the alloys. Alloys used in this investigation contained 15, 20, 33, 40, 42, 43, 45, 50, 55, 60, 63, 64, 66, 70, 79, and 80 wt pct 0s. Heat treatments of the alloy buttons and pieces thereof were performed in a previously described6 tungsten tube furnace under pressures of 105 torr or less. It was found that homogenization treatments on the specimens were essential to remove the severe coring which was present, a 3-hr treatment above 2300°C removing all the metallographi-cally visible evidence of coring. Following the various heat treatments, the specimens were "vacuum-quenched" by melting a tungsten fuse wire and allowing them to drop onto a water-cooled copper plate. In a few instances, specimens were quenched into molten tin for comparison, but no difference was apparent. Vacuum-quenched specimens cooled from 2400°C to below a red heat in less than 60 sec. Typical equilibration times varied from 3 hr above 2300°C to 88 hr near 1100°C. The utilization of successively longer equilibration times and the approach to equilibrium from both directions indicated that the times used were sufficient to give a close approach to true equilibrium. Heat-treatment temperatures were measured with a calibrated Leeds and Northrup optical pyrometer through a 0.120-in. lateral sight hole in the tungsten heater tube. It was known that the assumption of black-body conditions inside the 1-in.-diam by 10-in.-long tube was unwarranted. The empirical results of work with thermocouples and melting

Jan 1, 1964

By M. Kaufman, A. E. Palty

The phase structure and aging characteristics of two nickel-base alloys, Inconel 718 and 702, were investigated. Wrought and cast Inconel 718 showed ArisCb as the major hardening phase, as well as ture was positively identified. Inconel 702 had Ni3Al as the major hardening phase, as well as Cr7C3-of the phase amounts with temperature was determined. 1 HE value of phase structure and aging rate information in the utilization of alloys has been well established. As part of a continuing program, the results obtained on two nickel-base alloys, hconel 718 and Inconel 702, are presented here. Inconel 718 is a relatively new alloy considered for application in both sheet and cast form. Its novelty lies in the use of high columbium tantalum levels in a Ni-Cr-Fe base. No previous work on this type of alloy has been reported in the literature. Inconel 702 is being used now as an oxidation-resistant sheet alloy. Occasional fabrication problems spurred work on its basic structural behavior. The composition of 702 is essentially nichrome plus aluminum and titanium for strengthening and added oxidation resistance. This puts it in the basic class of other nickel-base alloys which have already been studied. The two alloys will be treated separately. INCONEL 718 Phase Study Methods. The phases present after the various conditions investigated were determined by X-ray diffraction analysis of two different elec-trolytically extracted residues and microscopic examination. The extraction methods, using 10 pct HC1 in alcohol and 10 pct H3PO, in water and the X-ray technique have been described previously.' The effect of temperature on the phase behavior was studied on sheet material using the following heat treatments: 2250°F, 2 hr, ice brine quench 1300 100 hr, water quench 2250°F, 2 hr, ice brine quench 1400°, 100 hr, water quench 2250°F, 2 hr, ice brine quench 1500°F, 100 hr, water quench 2250o 2 hr, ice brine quench 1700°F, 48 hr, water quench 2250°F, 2 hr, ice brine quench 1850°, 24 hr, water quench 2250°, 2 hr, ice brine quench 2000°F, 6 hr, water quench The high solution temperature was an attempt to dissolve as many phases as possible without causing melting. Aging exposures were made longer than normal heat treating times in order to approach equilibrium conditions more closely. Cast material was examined only in the as-cast condition and with the normal heat treatment (1700°F, 1 hr, air cool 1325oF, 16 hr,air cool). Materials. The full phase study was performed on sheet specimens approximately 1/2 in. by 2 in. by 1/16 in. The cast pieces were cut from the gating system of a vacuum-cast test piece. An all weld-metal specimen was made by running many weld beads on the sheet using filler made from the sheared edges of the sheet. All external contamination was removed by belt-sanding followed by an electro-polishing treatment. The typical composition of wrought Inco 718 is as follows: The alloy is air-melted. Cast hco 718 may have higher molybdenum. Due to the expectation of finding a Ni-Cb phase (Ni, Cb) for which no X-ray diffraction pattern was available in the ASTM Index, a special 5 Ib heat to the stoichiometric composition of this intermetallic

Jan 1, 1962

By William P. Mason

FoR reasons unnecessary to enter into here, I was called upon to contradict the statement that " closed metallic vessels, partly filled with water and heated, do not become shattered by violent explosion, but simply rupture by over-pressure;" and the following experimental results were obtained in support of my position : A piece of drawn brass tubing (telescope-tubing) 1 1/2 inches in diameter and 15 inches long was closed at both ends by screwing on heavy caps of bronze. Before closing the second end the vessel was half filled with river water, the cap was then screwed on, and the closed vessel was supported upon two iron anvils, and heated in the interval between the supports by a large Bunsen lamp. The resulting explosion (which was doe to over-pressure only and not to any more occult cause) was exceedingly violent. No small damage was done to the room in which the experiment was undertaken; and the noise was like that of a cannon. Those of the pieces which could be recovered are shown in Fig. 1. Upon examining the wreck, it was noticed that one of the heavy bronze end-caps had preserved its circular section and still contained that portion of the barrel of the tube which had been screwed into it, while the other end-cap contained no portion of the tube, and was moreover sprung into a shape more or less elliptical, as if from excessive lateral strain. It was also observed that the large pieces of the shattered boiler predominated towards the end which had been closed by the un-sprung end-cap. The reasonable explanation, in view of the facts, was, that over-pressure had caused the boiler to yield through the screw-threads at A B, Fig. 2, and the righthand end-cap had blown off, thus leaving the boiler half filled with water, greatly super-heated for the new (atmospheric) pressure to which it was suddenly reduced; that this water had consequently sprung instantly into steam with dynamite effect, shattering the tube and springing the remaining end-cap. The large pieces would be expected at the open end of the boiler, as at that point the "tamping "would have been that of the atmosphere only. This explanation assumes a rupture to have been caused by gradually increased pres-

Jan 1, 1893

By J. R. Campbell

The need for standardizing methods of arriving at definite conclusions regarding the cleanability of a given coal, and for measuring the performance of coal-cleaning equipment, is constantly increasing. Earlier notes by the author on this subject are amplified in this paper, because he believes that better preparation of bituminous coal is a partial solution of the coal operators' troubles. Washability Studies The term "washability" of coal was coined when washing was the universal method of separating coal from its impurities by utilizing their difference in specific gravity. This and analogous terms are still used in their broad sense although pneumatic or air separation is now used to clean coal. These terms are so used in this paper. Too much time or money can hardly be spent on "feed surveys') to get a "picture" of the coal that is to be cleaned. There have been too many "rule of thumb" methods used. Screen analyses and "sink-and-float" tests on the raw coal enable the coal operator and washery man to predict within reasonable limits the results that may be expected from any efficient cleaning apparatus. The sizes to be examined to get the picture are optional to the investigator. In modern wet washing, the range is from 4 to 0 in. Hand-picking on properly constructed belts is perhaps the standard for cleaning above these sizes. A good picture of the coal may be obtained by the following screen analysis: 3½ to 1¼ in. 1¼ to 3½ in. ½ to 5/16 in. 5/16 in. to 14 mesh 14 to 28 mesh 28 to 48 mesh and for very complete data on the fines: 48 to 100 mesh 100 to 200 mesh and through 200 mesh

Jan 1, 1930

By Donald Towse

Geothermal energy can substitute for and compete with other fuels, but until now it has been used only in special situations where it costs much less than alternate fuels. Geothermal heat is expected to be developed where it can: (1) compete with alternate fuels, (2) replace scarce fuels, (3) be more environmentally acceptable, or (4) is especially adapted to local needs. Economic problems in development include the often high capital costs of wells and gathering systems and the long lead-times required for electric generating plants. The large investment and long payout times for large industrial uses adversely affect the economics.

Jan 1, 1977

By P. Somasundaran, D. W. Fuerstenau

Adsorption isotherms for dodecyl sulfonate on alumina were determined at 45°C and 25°C and the data was used for calculating the partial molar heat and entropy of adsorbed ions under various concentrations. Changes in OH and AS observed at certain concentrations agree with the postulate of interaction of surfactant ions to form two-dimensional aggregates at the solid-liquid interface. Values of the total OH and AS for the aggregation process calculated using the Clausius-Clapeyron equation is used to interpret the interactions of surfactant ions with each other as well as with the solvent molecules.

Jan 1, 1973

By Louis Doremus Huntoon

HAVE been asked many times by financial men in New York as to the best way of securing an interest or control of a gold mine in Canada. It must be understood at the start that prospectors and early owners will not sell a 100 per cent interest. They not only retain from 10 to 25 per cent interest, depending upon the work done, but usually demand more or less cash to reimburse them for expenses. These conditions are accepted by Canadian capital and operating mines looking for new properties. The winter is not a hindrance to work but may be of great advantage. The overburden of soil and gravel is generally wet and most difficult to trench in the summer time especially if at all deep. The snow also permits easy transportation of freight. Properties distant from rail transport all of their machinery and supplies during the winter months.

Jan 1, 1933

By Edward B. Durham

At the Richmond mecting in February, 1901, I presented for discussion the proposed rail-specifications of Committee No. 1 of the American Section of the International Association for Testing Materials, with a review of their work, and other matters relating to the heat-treatment and chemical composition of steel (Trans., xxxi., 455). In order to bring out the views of our members on the important points referred to, I offered for discussion the following questions and comments (trans., xxxi., 972): " 1. The advantages to be gained by using more metal in the flanges and web of the heavier sections of rails.

Jan 1, 1903

My question relates to tundish nozzle plugging on aluminum-killed heats. North Star has avoided this problem by silicon deoxidation. What has been Inland's experience with this problem on open-pour and submerged nozzle pouring?

Jan 1, 1972

An extended investigation by the chief engineer of the Bureau of Mines shows that North Dakota has immense beds of lignite. War conditions have stimulated the use of North Dakota lignite until it is now being used at the rate of 1,000,000 tons annually. This North Dakota lignite is coming into extensive local use and considerable of it is being shipped to various parts of the state. The great problem at the present time is to find a market for the gas, which is the principal-by-product of lignite preparation. Bureau of Mines specialists will complete their reports of the studies of lignite in this country and will then make a recommendation as to the lignite field which is best suited for the establishment of the proposed Government's experimental plant. "Broken eggs cannot be mended."-(Lincoln.) Neither can "cashed in" War Saving Stamps grow to their maturity value.

Jan 8, 1919

By E. C. Pechin

THE Lucy furnace, owned by Messrs. Carnegie, Kloman & Co., and located on the Alleghany River, on the outskirts of Pittsburgh, is a splendid modern furnace, 75 feet high, and 20 feet bosh. She had been working well on low grade ores of about 50 per cent., producing daily 68 to 75 tons. There was on stock 500 tons of Republic ore, one of the purest and best of the Lake Superior ores, averaging over 68 per cent. of iron, which had been procured for the purpose of making a trial for Bessemer iron. This was charged by itself, and Mr. Skelding, the founder, reports that he did not succeed in getting a single cast when it came down, before the furnace chilled from the hearth to the top of the boshes, some 25 feet. Every effort was made to save her, without avail, and the disagree-

Jan 1, 1874

By Edmund C. Pechin

The Lucy furnace, owned by Messrs. Carnegie, Kloman & Co., and located on the Alleghany River, on the outskirts of Pittsburgh, is a splendid modern furnace, 75 feet high, and 20 feet bosh. She had been working well on low grade ores of about 50 per cent., producing daily 68 to 75 tons. There was on stock 500 tons of Republic ore, one of the purest and best of the Lake Superior ores, averaging over 68 per cent. of iron, which had been procured for the purpose of making a trial for Bessemer iron. This was charged by itself, and Mr. Skelding, the founder, reports that he did not succeed in getting a single cast when it came down, before the furnace chilled from the hearth to the top of the boshes, some 25 feet. Every effort was made to save her, without avail, and the disagree-

PICK AND SHOVEL CLUB, CASE SCHOOL OF APPLIED SCIENCE The last meeting of the year of the Pick and Shovel Club of Case School of Applied Science was held on May 20, 1919. The speaker, Dr. Zay Jeffries, gave a very instructive and interesting talk on the Metallography of Non-ferrous Metals. The club has had a very successful year in spite of the loss of a few months time through the S. A. T. C. Among the speakers for the year were Dr. F. R. Van Horn, Dr. C. H. Fulton, and Dr. W. R. Veazey of our school; Dr. E. S. Moore of Penn. State College; Dr. Ansel St. John, of the National Carbon Co.; and Mr. V. S. Bidle, of the W. S. Bidle Co. The graduating members wish the club the best of success for the coming year. BERTRAND R. WARMELING, Secretary.

Jan 7, 1919

By J. W. Fuller

During the last 20 years, experimenters have sought to utilize pulverized coal in boiler plants, but refractory and slag troubles have usually overbalanced any gains in efficiency that were obtained. These troubles were caused largely by lack of knowledge of the proper methods of coal preparation and lack of a furnace design that would be adaptable to pulverized-coal firing. When this information was obtained the results were so much more satisfactory that within the last 5 years approximately 80,000 boiler hp. have been installed in plants ranging from 1000 to 20,000 boiler hp. rated capacity, which are operating at an average of 174 per cent. of rating. The first commercial installation for burning pulverized coal under boilers was made at the Parsons shops of the M. K. & T. railroad in 1916. Of eight 250-hp. water-tube boilers thus fitted, six were operated continuously for 3 yr., when oil was obtained at such a low price as to warrant its use. Since then, this plant has been operating alternately on pulverized coal and oil, depending on prevailing prices. Recently gas has been discovered within 20 mi. of this plant, so that this fuel may also be used. No change in furnace design was made when changing from pulverized coal to oil or gas firing. One of the principal advantages of this method of firing is its ability to utilize, with maximum efficiency, all kinds of coal, irrespective of quality or physical characteristics. In fact, quite a number of the present pulverized-coal installations were made for the purpose of utilizing coal that could not be marketed or used in any other way. The Pacific Coast Coal Co., at Black Diamond, Wash., formerly hand fired the boilers, using approximately 125 tons of prepared steam-size coal daily. The Black Diamond steam coal is the best quality of coal for steaming purposes mined in that section of the country, and there is a market for all that can be produced. By installing a pulverizing plant, it was possible to substitute coal of a size and quality that had no commercial value, so that 125 tons daily of the best steam coal formerly used at the mines is now marketed. This company made a similar installation, at its New Castle, Wash., mine with approximately similar results. Each of these two plants has a

Jan 1, 1922

By C. S. Chang

Replacement of active groups in corn starch, as shown by results of the starch derivatives tested, impairs rather than improves the value of corn starch as a selective iron oxide depressant. Increased ability to depress iron oxides is generally accompanied by a parallel ability to depress quartz. PEARL starch, a corn starch prepared with a minimum of alteration, is a good selective depressant for iron oxide minerals.' From what is known of the complex chemistry of corn starch, there is evidence that it consists of a mixture of saturated giant polymeric molecules, both straight and branch-chained, the constituents consisting of glucose units with hydroxyl radicals as active or polar groups. To add to the existing knowledge of the chemistry of the flotation process, it is desirable to ascertain the effects on the corn starch as an iron oxide depres-

Jan 1, 1955

By W. L. Fink, R. S. Archer

THIS paper describes results obtained on aluminum-beryllium alloys and aluminum-beryllium-copper alloys in the preparation of which aluminum of 99.95 per cent. purity was used. The constitution and structure of the high purity binary alloys are given. The aluminum-beryllium eutectic occurs at 0.87 per cent. beryllium and 645° C. The solid solubility of beryllium in aluminum at 631° C. is 0.05 per cent. beryllium, and at room temperature is less than 0.013 per cent. beryllium. The densities of the alloys are substantially the same as the values calculated on the assumption that the densities of the elements are not changed by alloying. All of the alloys age-harden at room temperature after a solution heat treatment, and the chill cast aluminum-beryllium-copper alloys age-harden at room temperature without a prior solution heat treatment. Hardness and tensile properties are given. Salt spray corrosion tests on sheet specimens are described. It is shown that beryllium does not lower the corrosion resistance of aluminum to salt spray provided the alloy has received a solution heat treatment. COMMERCIAL POSSIBILITIES OF BERYLLIUM ALLOYS Beryllium has certain properties such as low density, high hardness, good corrosion resistance, low thermal expansion and fairly good electrical conductivity, which would indicate that it is worthy of consideration as an ingredient of light alloys. It was not until recently, however, that beryllium could be produced with sufficient ease to encourage research along this line. The production of beryllium by electrolysis from a fluoride bath has now developed to the stage where it could be used commercially if there were sufficient demand for the element. Claims made in certain newspapers and technical articles in regard to the strength and corrosion resistance of the aluminum-beryllium alloys are not justified by experimental results. Moreover, beryllium is an expensive metal ($200 a pound at the time this work was done) and, on account of the nature of its ore and the consequent difficulty of its extraction, it will in all probability continue to be a relatively expensive metal, although the cost would undoubtedly be a great deal less than $200 a

Jan 1, 1928

By W. L. Fink, R. S. Archer

This paper describes results obtained on aluminum-beryllium alloys and aluminum-beryllium-copper alloys in the preparation of which aluminum of 99.95 per cent. purity was used. The constitution and structure of the high purity binary alloys are given. The aluminum-beryllium eutectic occurs at 0.87 per cent. beryllium and 645° C. The solid solubility of beryllium in aluminum at 631° C. is 0.05 per cent, beryllium, and at room temperature is less than 0.013 per cent. beryllium. The densities of the alloys are substantially the same as the values calculated on the assumption that the densities of the elements are not changed by alloying. All of the alloys age-harden at room temperature after a solution heat treatment, and the chill cast aluminum-beryllium-copper alloys age-harden at room temperature without a prior solution heat treatment. Hardness and tensile properties are given. Salt spray corrosion tests on sheet specimens are described. It is shown that beryllium docs not lower the corrosion resistance of aluminum to salt spray provided the alloy has received a solution heat treatment. Commercial Possibilities of Beryllium Alloys Beryllium has certain properties such as low density, high hardness, good corrosion resistance, low thermal expansion and fairly good electrical conductivity, which would indicate that it is worthy of consideration as an ingredient of light alloys. It was not until recently, however, that beryllium could be produced with sufficient ease to encourage research along this line. The production of beryllium by electrolysis from a fluoride bath has now developed to the stage where it could be used commercially if there were sufficient demand for the element. Claims made in certain newspapers and technical articles in regard to thc strength and corrosion resistance of thc aluminum-beryllium alloys are not justified by experimental results. Moreover, beryllium is an expensive metal ($200 a pound at the time this work was done) and, on account of the nature of its ore and the consequent difficulty of its extraction, it will in all probability continue to be a relatively expensive metal, although the cost would undoubtedly be a great deal less than $200 a

By R. A. Wagstaff

THE method of charging a reverberatory furnace has changed many times since smelting was introduced in this country from the old smelters of Swansea, England. The cause of the latest change at the Garfield plant has been the excessive fineness of the charge due to fine grinding in the concentration of the crude copper ores. The many desirable features of deep-bath smelting as now used at Garfield have been proved. The old method of dropping the charge through holes in the arch (known as center-feed method) causes excessive dusting which makes heavy slag and causes flue-dust losses, also rapid deterioration of the silica brickwork of the furnace through fusion .with the iron oxides from the dust. The purpose of this paper is to describe a gun feeder that was designed to overcome the disadvantages of the older methods of center feeding and still maintain the good features of deep-bath smelting with the hot finer charge. A gun feeder was designed to introduce the finely divided hot calcines under the moving gas stream of the combustion zone and still have them spread in a uniform blanket over the highly heated matte bath. The temperature of the furnace was so great that it was impossible to maintain a stationary feeder, so a movable feeder was designed that could be introduced into the highly heated zone and be withdrawn after the charge had been dropped. It was necessary to protect the nozzle of the gun with a water-cooled coil. Many different types of protected nozzles were tried, such as air jackets, water jackets and heat-resisting steel alloys, but none proved satisfactory.

Jan 1, 1932