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By E. P. Abrahamson II

The effect of transition elements which form binary solid solution upon the recrystallization temperature of zirconium has been investigated. All additions raised the recrystallization temperature. A correlation is obtained between the logarithm of the rate of change of recrystallization temperature with atomic percent solute and the free atom ground state electron configuration of the solute element. ThE work of Abrahamson, et al., on dilute binary solid-solution alloys indicated a correlation between the free-atom ground state electron configuration of the solute and either the brittle-ductile transition or recrystallization temperature. These studies were carried out on bcc base materials. The implication is that the outer s and d electrons of the solute are the prime determinant of the absolute rate of change of recrystallization or transition temperature. Furthermore, the limit of linearity has been shown to be a function of solute electron configuration for recrystallization in iron and vanadium. To date no Complete systematic recrystallization study of dilute binary zirconium base alloys has been made. It is the purpose of this study to note whether the change in solvent structure from bcc to hcp will influence the correlation. It was also desired to learn more of the role of the electron configuration of the solvent on recrystallization temperature. PROCEDURE All alloys were made using 99.87 pct Zr with 0.01 Cr, 0.04 Fe, 0.006 Hf, 0.003 Mg, 0.003 Mn, 0.003 N, and 0.080 0 (132 BHN). The solute elements were 99.9 pct pure. According to the published binary phase diagrams6 and metallographic examinations at X750, all alloys used were solid solutions. The alloys were arc melted and remelted six times in the form of cubic 200-g buttons under an argon atmosphere. They were then hot pressed at 950°C to 0.450 in., upset pressed to 0.350 in., and annealed at 800°C for 1 hr. The specimens were then Blanchard ground to 0.250 in., removing 0.050 in. from each side. The grain size of the material at this stage was found to be 8000 100 grains per sq mm. The specimens were then cold rolled to 0.130 in. and cold pressed to 0.125 in., yielding 50 1 pct cold work. All alloys were then chemically analyzed for the principal addition. The interstitial contents remained at the values of the starting material when checked on random alloy specimens. The rolled sheet was cut into 6.75 by 0.25-in. lengths and heat treated in a gradient furnace for 1 hr. The gradient was 250o to 900°C over the 6-in. length, recorded continuously by six thermocouples resting on each specimen. Control was 3oC, accomplished at the hot end. The recrystallization temperature was determined metallographically using polarized light. The criterion chosen was the point on the specimen showing the first recrystallized grain at a constant magnification, X200. Specimens were repeated, and the agreement was found to be 3°C. RESULTS Three different pure zirconium specimens were tested, and the recrystallization temperature was

Jan 1, 1962

Executive Committee, Board of Directors Grover J Holt, Chairman, C E Reistle, Jr , Vice-Chairman, A W Thornton, A B Kinzel, J L Gillson Finance Committee, Board of Directors Andrew Fletcher, Chairman, R B Caples, Gail F Moulton Investments Erle Daveler, '60, Chairman, Henry Krumb, '59, John Warren, '60, C R Dod¬son, ex off as Treasurer, Andrew Fletcher, ex off as Chairman, Finance Committee Endowment Andrew Fletcher, Chairman, N G Alford, E V Daveler, W J Coulter, J V N Dorr, R B Gilmore, J B Haffner, 0 H Johnson, D H McLaughlin, J R McMillan, L F Reinartz, C E Weed, Wilfred Sykes, J R Suman Honorary Memberships L F Reinartz, Chairman, C E Reistle, Jr , H DeWitt Smith, ex off as Past Presidents of AIMS, Grover J Holt, ex off as President AIMS, P D Merica, '59, Henry Krumb, '58, M L Haider, '60, D H McLaughlin, '61

Jan 1, 1957

By I. H. Van Horn

IN the development of the incandescent electric lamp one aim of the investigators has been to establish the fundamentals of lamp design, so that the performance of any new lamp may be accurately predicted. The study of the temperature relations in lamps has done much toward establishing these fundamentals. Fig. 1 gives the typical FIG. 1.-ARRANGEMENT OF PARTS IN MAZDA B AND MAZDA C LAMPS. arrangement of the lamp parts in both the Mazda B (vacuum) and Mazda C (gas-filled) lamps. The outstanding differences are the filament form and the bulb shape. The ideal lamp is one in which the filament operates at a uniform temperature throughout its length. In practice, it is necessary to disturb this uniformity by the introduction of supports and terminals. The amount of cooling at the supports and terminals affects the over-all efficiency of the filament as a light producer. The life of the lamp is ordinarily proportional to the maximum and not to the average filament temperature. The Holborn-Kurlbaum type of optical pyrometer has

Jan 9, 1919

Temperatures in the Open-hearth Furnace. By Robert B. Sosman. (Metals Tech. Aug. 1948, T.P. 2435) Steelmaking Direct Oxidation in the Basic Open Hearth Process. By E. R. Hughes and F. G. Norris. (Metals Tech., June 1948, T.P. 2380) With discussion Operation of Oxygen-enriched Open-hearth Furnaces. By J. S. Marsh. (Metals Tech., Aug. 1948, T. P. 2416) With discussion Role of Thermochemical Factors in Basic Open Hearth Production Rate. By T. E. Brower and B. M. Larsen. (Metals Tech., Oct. 1948, T.P. 2451) Structure, Segregation and Solidihcation of Semikilled Steel Ingots. By M. Tenenbaum. (Metals Tech., Sept. 1947, T.P. 2273) With discussion The Origin of Silicate Inclusions in Basic Electric-arc-furnace Steel of Higher Carbon Contents. By Axel Hultgren. (Metals Tech., Aug. 1948, T.P. 2418) A Method for Determining the Origin of Surface Defects in Rolled Steel Products. By C. L. Meyette and V. L. Elliott. (Metals Terh., June 1948, T.P. 2368) With discussion Gases in Steel The Sampling and Analysis of Steel for Hydrogen. By G. Derge, W. Peifer and J. H. Richards. (Metals Tech., June 1948, T.P. 2362) With discussion Apparatus for the Hot-extraction Analysis for Hydrogen in Steel. By C E. Sims and G. .I. Moore. (Metals Tech., June 1948, T.P. 2369) With discussion A Quantitative Experimental Investigation of the Hydrogen and Nitrogen Contents of Steel during Commercial Melting. By C. E. Sims, G. A. Moore and D. W. Williams. (Metals Tech., Feb. 1948, T.P. 2347) With discussion The Effect of Hydrogen on the Ductility of Cast Steels. By C. E. Sims, G. A. Moore and D. W. Williams. (Metals Tech., Sept. 1948, T.P. 2454) Sulphur in Ironmaking Kinetics of the Transfer of Sulphur across a Slag-metal Interface. By Lo-ching Chang and K. Goldman. (Metals Tech., June 1948, T.P. 2367) With discussion Some Correlations between Variables Affecting Sulphur in Blast Furnace Iron. By T. E. Brower and B. M. Larsen. (Metals Tech., Sept. 1948, T.P. 2465) Tracer Study of Sulphur in the Coke Oven. By S. E. Eaton, R. W. Hyde and 11. S. Old. (Metals Tech., Sept. 1948, T.P. 2453) Transformation of Austenite Anisothermal Formation of Bainite and Proeutectoid Constituents in Steels. By Leonard D. Jaffe. (Metals Tech., Dec. 1947, T.P. 2290) With discussion Austenite Transformation Above and Within the Martensite Range. By R. T. Howard, Jr. and M. Cohen. (Metals Tech., Oct. 1947, T.P. 2283) With discussion

Jan 1, 1949

Apr. 26-May 11, Liege International Fair, Liege, Belgium. May 4-8, Electrochemical Society, Inc., Spring meeting, Benjamin Franklin Hotel, Philadelphia. May 5-6, National Air Pollution Symposium, Huntington Hotel, Pasadena. May 5-7, American. Mining Congress, coal convention, Netherland Plaza Hotel, Cincinnati. May 6-9, Scientific Apparatus Makers Assn., annual meeting, Edgewater Beach Hotel, Chicago. May 9-10, AIME, joint meeting, Industrial Minerals Div. and Metals Branch, Davenport Hotel, Spokane, Wash. May 11-14, American Institute of Chemical Engineers, Atlanta Biltmore Hotel, Atlanta. May 17, AIME, Chicago Section, President's night dinner dance, Shoreland Hotel, Chicago. May 27, AIME, Morenci Subsection, Longfellow Inn, Morenci, Ariz. June 2-4, Chemical Institute of Canada, annual conference, Montreal. June 4-14, Mechanical Handling Exhibition and Convention, Olympia, London.

Jan 1, 1952

By Hans Conrad, W. D. Robertson

FORMAL theories of yielding and flow have been developed to describe thermally activated plastic flow in metal crystals.'-" hey are all based on Becker's' original idea that thermal fluctuations aid the applied stress in overcoming internal barriers to flow and lead to the following relation. where j is the strain rate; C is a constant which includes a frequency factor, the entropy, the number of flow units, and the amount of strain associated with each successful fluctuation; E(T) is the activation energy associated with flow, and is a decreasing function of the applied stress, 7; k is Boltzmann's constant; and T is the temperature in OK. The various theories differ mainly in the model chosen and in the nature of the relationship between the applied stress and the activation energy. Beckerl and Orowan' suggest a relationship of the form E a(Ti — t)2, where .ri represents the stress required for flow without the aid of thermal fluctuations; Kauzmann,3 Cottrel1,5 and Seeger6,7 suggest E a(t — t) ; Fisher8 suggests E while Cottrell and Bilby4 suggest a more complex relationship between E and 7. Additional data are needed to test these various theories., esweciallv- in view of Dorn's9 ork. which indicates that the activation energy for creep is independent of the stress and strain. The present paper presents the stress-strain data derived from incremental loading of magnesium single crystals in tension and direct shear, in the temperature range of 78" to 364°K. Incremental loading was employed in order that the creep component of the strain could be determined. Stress-strain curves of aluminum10-13 and copper" single crvstals. derived from incremental loading tests, have been found to be in agreement with those obtained by the more conventional constant strain rate or loading rate tests. Two types of tests were conducted in the present investigation: 1) tests in which the temperature was maintained constant throughout the entire

Jan 1, 1958

By C. Crussard, R. Tamhankar

It is the policy of The Metallurgical Society to provide, in the TRANSACTIONS OF THE METALLURGICAL SOCIETY OF AIME, a prompt and accurate medium for publication of reports of significant new research in both the scientific and engineering aspects of metallurgy. Papers submitted to the Society are judged by competent reviewers accord-ing to established criteria for technical merit, accuracy, originality, and presentation. STAFF: Editor, Gerhurd Derge Carnegie Institute of Technology Schenley Park Pittsburgh 13, Pa. Editorial Assistant, M. A. Redmerski Staff Coordinator, James J. Burke THE METALLURGICAL SOCIETY: W. R. Hibbard, Jr., President; J. C. Kinnear, Jr., Past-President; John Chiprnan, Vice President; T. D. Jones, Treasurer; R. W. Shearman, Secretary. PUBLICATIONS COMMITTEE OF THE METALLURGICAL SOCIETY: A. W. Thornton, Chairman; Dennis Carney, John Chip-man, J. C. Fulton, J. H. Hollomon, H. H. Kellogg, A. E. Lee, R. Maddin, J. D. Sullivan, and D. Swan. Review and selection of manuscripts is under the supervision of the following Publications Committees: Extractive Metallurgy Division: T. B. King, Chairman; S. J. Dickenson, R. P. Hermsdorf, R. Schuhmann, Jr., and P. T. Stroup. Institute of Metals Division: Robert Maddin, Chairman, F. Lincoln Vogel, Jr., Vice-chairman, W. A. Backofen, R. W. Balluffi, J. H. Bechtold, M. B. Bever, R. S. Busk, C. G. Goetzel, Paul Gordon, C. D. Graham, .Jr., Robert F. Hehemonn, R. I. Jaffee, F. E. Jaumot, Jr., Irving R. Kramer, A. J. Lena, Harold Margolin, C. J. McHorgue, Russell A. Meussner, J. B. Newkirk, H. W. Paxton, G. E. Pellissier, I. S. Servi, Alan U. Seybolt, A. J. Shaler, and Jack Washburn. Iron and Steel Division: J. C. Fulton, Chairman; T. B. King, F. C. Langenberg, W. 0. Philbrook, and T. 0. Winkler. Published bimonthly by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc., 29 West 39th Street, New York 18, N. Y. Telephone: PEnnsylvania 6-9220. Subscription $20 per year for non-AIME members in United States and North, South, and Central America; $25, foreign; $5 for AIME members. Single copies, $4.00, single copies foreign, $5.00. The AIME is not responsible for any statement made or opinion expressed in its publications . . . Copyright 1958 by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. . . . Registered cable address, AIME New York ... Indexed in Engineering Index, Industrial Arts Index, and Chemical Abstracts... Second class postage paid at New Yark, N. Y., and Ann Arbor, Mich. Volume 212, Number 6.

Jan 1, 1959

By Charles Luner

ALTHOUGH the kinetics of the atmospheric oxidation of tin have been studied,1-3 the kinetics in pure oxygen have not been reported. This note presents some results of the kinetics of the oxidation of tin foil in pure oxygen. The tin foil used in this investigation was 99.78 pct pure, the two major impurities being Pb (0.17 pct) and Sb (0.024 pct). The foil was degreased and air-dried prior to oxidation. The air-formed film was estimated by coulometric reduction4 of the surface oxides to be about 25A. The samples, which were in strip form and had a total geometric surface area of about 300 sq cm, were first evacuated at room temperature in an oxidation bulb to 1 X 10 -5 mm Hg and subsequently degassed for 1 hr at the temperature of the experiment. Spectroscopically pure oxygen was then introduced into the bulb. The rates of oxidation were measured by following the rate of pressure change due to oxygen consumption in a closed system, the volume of which was sufficiently large so that the pressure change during an experiment was 10 to 15 per cent of the total pressure. An oil-mercury manometer,5 with a sensitivity of 3 X x mm Hg (which corresponds approximately to 5 X 10 -7 gm of oxygen) was used to measure the pressure change. The oxidation bulb was heated by an oil-bath and controlled to within -10.3 C. The reproducibility of the rates was good, as determined by the coincidence of rates at 190oC for duplicate experiments. Fig. 1 shows the oxidation curves in the temperature range 168 to 211.5oC at 8 mm Hg pressure. The effect of pressure on the rate of oxidation at 190°C is also shown. The rate of oxidation was not markedly affected by changes in pressure in the range 4 to 9 mm Hg, except perhaps at the lowest pressure, 4 mm Hg, where after about 70 min there appeared to be a decline in the rate, as compared with the rate at the higher pressures. At the lower tem- perature, 168oC, and for short reaction times, it is difficult to distinguish between a linear relationship and a slight curvature in the oxidation rate. However, for longer times, there was a somewhat larger indication of curvature. The samples after oxidation were gold-colored in appearance. The oxide that was formed at 170°C was identified as a-SnO by reflection electron diffraction. This is in agreement with results obtained by other workers.6, 7 The rate data best fitted the logarithmic-oxidation rate law, w = K1n ln(1 + -t/to) [1] where w is the weight of oxygen consumed, t is the time, and K In, and to are constants. First estimates to were obtained according to the method of Taylor Thon8 and were then employed to obtain the best simuItaneous estimates of to and K In, that would fit the logarithmic expression. These estimates were found numerically, so that the residual variance could be minimized. The calculations were performed on an

Jan 1, 1961

By Jerome F. Kuzmick

Condusions. From the work on aluminum powder, the following general con clusions can bc drawn: I. The physical properties of aluminum compacts, such as density. strength and ductility, increase with increasing pressure, up to the practicable pressure limits. 2. Good properties ill aluminum con pacts can be secured only by the use of high pressures, because it is neccssary to rupture the refractory oxide film on aluminum powder. 3. Considerable softening of the specimens occurs upon sintering. regardlers of the pressure used. General Conclusions 1. For relatively short-time sintering. molding pressure is a very important factor in the final physical properties of the sintered specimens. 2. The effect of pressure. is difierent for each metal, so that few general rules can be drawn that would apply to all metals. 3. In many cases, fur a particular metal powder and sintering temperature there is a critical pressure at which the best physical properties can be obtained. 4. The principles of cold work and in nealing and their effect on grain structure applied to massive metal also holds true for sintered metals. 5. Particle size, at least for electrolytic iron powder, does not have a. great effect on ultimate grain six. DISCUSSION [E. E, Schumacher presiding V.. V. Crane. *—I was particularly impressed with Dr. Kuzmick's work on tin IF not the illustration, particularly the Second one. a very good illustraition of hot preessing. in that

Jan 1, 1945

By A. Timur

Fluid flow properties of porous media have long been of interest in such varied disciplines as geology, geophysics, soil mechanics, and chemical, civil, and mechanical engineering. This interest has resulted in numerous models of porous media that have been proposed, tested, and found to be useful under, at best, only special circumstances. A critical review of most of these models is given by Scheidegger. 1 The application of each new tool to the study of porous media has helped to test some of the existing theories and to form new ideas based on the new parameters being measured. In the application of nuclear magnetic resonance (NMR) techniques to the study of the properties of fluids in porous media, the theoretical studies of Korringa et al.2 resulted in a model for the relaxation of spin polarization of protons in a hydrogenous fluid in a pore of a solid. Seevers3,4 verified this model, established a method for measuring the surface-to-volume-ratio distribution in a porous medium, and proposed a technique for determining specific permeability in sandstones. In the present investigation, the uses of NMR methods are extended and a simple model of porous media is developed from an analysis of pulsed NMR measurements. In this model, the pore spaces of a porous medium are divided into three groups on the basis of their surface-to-volume ratios. To evaluate predictions of the NMR model, laboratory measurements of spin-lattice relaxation time, porosity, permeability, and residual (irreducible) water saturation were conducted on more than 150 sandstone samples obtained from four oil fields in North America. Applications are discussed for estimating the volume of movable fluid, ?p, and the specific permeability, k, of sandstone samples. The former parameter, which can be considered as producible porosity, is expressed by ?p = [1 -- (Swr/100)]? , .... (1) where + is porosity in percent of bulk volume and Swr is the residual (irreducible) water saturation in percent of pore volume at a capillary pressure of 50 Psi. Fast, nondestructive laboratory methods are described for determining porosity, movable fluid, and permeability of sandstone samples from measurements with a pulsed NMR (spin-echo) apparatus. Procedures are given for adapting these methods to samples of irregular shape and small size. Theory General In the Korringa, Seevers, and Torrey2 (KST) model the observed decrease in the spin-lattice relaxation time, T1, of protons of a hydrogenous liquid contained in the pore spaces of a porous solid is attributed to an increase in the correlation time for the random motion of the water molecules and to the presence of paramagnetic centers at the liquid-solid interface. This KST model predicts the observed relaxation time of a hydrogenous liquid in a pore of a solid through

Jan 1, 1970

By AIME AIME

COMMITTEES. LOCAL COMMITTEE.-R. C. Crawford, Chairman; Harrison W. Craver, Secretary; Julian Kennedy, Taylor Allderdice, E. W. Pargny, Charles L. Miller, W. H. Rea, S. A. Taylor, M. E. Wadsworth, W. A1. Henderon, A. C. Dinkey, W. L, Jones, E. L. Messier, George Mesta, J. H. Jones, G. H. Riley, S. L. Goodale, D. W. McNaugher. LADIES' COMMITTEE.-Mrs. Taylor Allderdice, Chairman; Mrs. Julian Kennedy, Mr. R. C. Crawford, Mrs. E. M. Herr, Airs. J. W. Marsh, Mrs. T. A. Mellon, Mrs. G. P. Bassett, Jr., Airs. D. M. Clemson, Mr. Charles L. Miller, Mrs. V. L. P. Shriver, Mrs. W. A. Bostwick, Mrs. A. C.. Dinkey, Mrs. A. P. Childs, Jr., Mrs. F. R. Dravo, Mrs. Hermon Griffin, Mrs. W. H. Nimmick, Mrs. F. H. Lloyd, Mrs. S. G. Cooper, Mrs. S. H. Church, Mrs. E. N. Ohl. The Institute Headquarters was established at the Hotel Schenley, where a bureau of information was maintained for the benefit of the visiting members and guests of the party during the time of the meeting. TECHNICAL SESSIONS. The first session, held Tuesday evening, Mar. 1, 1910, in the large lecture hall of the Carnegie Institute, was called to order by Harrison W. Craver, Secretary of the Local Committee. Mr. Craver introduced Dr. John A. Brashear, who extended to the members and guests a hearty welcome to the city of Pittsburg, to which David W. Brunton, President of the Institute, responded. The following papers were presented in oral abstract by the authors: Biographical Notice of Dr. Charles B. Dudley, by Dr. R. W. Raymond, New York, N. Y. Biographical Notice of William Metcalf, by Col. II. P. Bope, Pittsburg, Pa. Development of Hindered Settling Apparatus, by Robert H. Richards, Boston, Mass. (Illustrated by lantern-slides.) A Few Mining Districts in the Argentine Republic, South America, by Z. S. Beyl. (Illustrated by lantern. slides.)

Apr 1, 1910

By R. H. Goodrich

Development in this district during the year 1929 was little different from that of any other year despite the somewhat depressed condition of the oil business in general. The year was marked by: (1) An intensive geophysical campaign in the search of deep-seated salt domes; (2) the rather successful exploration and development of lateral sand production on the flanks of some of the older domes. Geophysical Exploration Geophysical work is confined almost exclusively to the torsion balance and seismograph. At the beginning of the year there were approximately 185 individual instruments of all types engaged in the search of structures in the Gulf Coast of Texas and Louisiana. This total includes 3 magnetometers, 83 torsion balances and 100 seismographs. The number of parties operating the torsion balances was 47; seismographs, 20; magnetometers, 3. It is estimated that 4,800,000 lb. of dynamite or other explosives were used in seismic exploration. During the year the torsion balance and seismograph were credited with having discovered the following salt domes: Texas, Danbury dome, Brazoria County, H. & T. B. R. Co., and Clodine dome, Fort Bend County, John Fredricks and Wm. Stanley, Satowsky Survey; Louisiana, Iowa dome, Calcasieu and Jefferson Davis Parishes, T. 9 S., R. 6 and 7 W., and Cameron-Meadow dome, Cameron Parish, T. 14 S., R. 13 W. Because of the secrecy maintained in these developments, it is somewhat hazardous to venture opinion as to the number of salt domes found during one year. The discovery of gas at Mykawa district and at Genoa district, in Harris County, Texas, is considered of more than passing importance, because there is indication in the performance of these two districts that commercial accumulation of oil and gas may be found in the Gulf Coast on structures other than the wore or less definite salt dome type. While it is generally conceded that the accompanying structure in these instances are deeply buried salt domes, it is a fact that neither the seismograph nor the drill have indicated the presence of salt.

Jan 1, 1930

By K. E. Merklin, F. D. DeVaney

Students of the modern blast furnace seem unanimously agreed that they are observing a major revolution in practice. Rather than changing construction and operation of the furnaces, most of the great advances now under way deal with the raw materials feed. Prepared burdens have gained increasing significance during recent years. Sizing, concentration, and agglomeration have all become bywords to greater production and reduced operating costs. The remarkable results with test furnaces in which self-fluxing sinter makes up part or all of the ore charge foretell even greater improvements. Other investigators have reported many of these advances, and it is enough to predict here that more and more operators will turn to the use of self-fluxing sinter. This change in the operator's requirements comes at a time when one major section of the iron ore regions, the Mesabi, is finding it difficult to maintain, let alone improve, the tonnage and grade of its shipping product. To meet the new demands with respect to quality and structure, the iron ore producers of this area turned first to screening, crushing, and concentrating intermediate ores. More recently, declining higher-grade reserves have led to multimillion-dollar investments in plants to treat the low-grade magnetic taconites.1,2 To yield a suitable concentrate, the Minnesota magnetic taconites must be ground to about 80 pct through 325 mesh, too fine to be charged directly to the blast furnace or to make acceptable feed to the sinter strand. The pelletizing process was developed to meet the structure requirements laid down by the blast furnace operators. Taconite producers are succeeding in their efforts just when the attention of the blast furnace man is being drawn to the great advantages of self-fluxing sinter.3 The taconite operators are ready with an alternative. Why not produce sclf-flus ing pellets? At the Hibbing laboratory of Pickands Mather & Co., where much of the early work was done that led to Erie Mining's 7.5-million ton taconite plant at Hoyt Lakes, Minn., preliminary investigations have been made. Present Taconite Operations: Details of this work will be clarified by a brief review of agglomeration practice in commercial taconite plants. After the taconite has been ground to about 80 pct through 325 mesh to liberate the magnetite grains, the ore is concentrated on magnetic separators, thickened, and filtered to about 10 pct moisture. This structure and moisture fit in closely with the conditions required to produce good balls. It has been found with taconite concentrates that at least 60 pct of the feed to the balling drum must be —325 mesh to obtain good ball compaction within reasonable time. The filter cake moisture usually permits a slight water addition at the balling drum, and further balling control is obtained by adding about 12 Ib of bentonite and 1 1/2 lb of soda ash per dry short ton of concentrate. These additives, and occasionally small quantities of fine coal, are thoroughly mixed with the filter cake ahead of balling. The swelling property of bentonite improves the green and dry strength of the balls so they can be handled without breakage until they are fired. Soda ash is added for pH control to insure maximum performance of the bentonite, and coal is added for more heat in the firing process when required. The balls, normally 3/8 to l-in. diam, are brought to a temperature of 2350" to 2500°F in the indurating furnace. Heat for this process comes from three sources: 1) fuel burned in the combustion chamber, 2) oxidation of the magnetite concentrates to hematite, and 3) coal added to the balls. Pellet strength is developed by grain growth and bridging and, if enough slag-forming constituents are present, by slag bonding. Conversion to hematite is usually close to 100 pct in the fired pellets. Batch Test Procedures: Initial studies of self-fluxing pellets were made by producing balls on a batch basis under carefully controlled laboratory conditions. The l-in. balls, uniform in size, were fired in an oxidizing atmosphere in a standard laboratory muffle furnace. The firing procedure consisted of

Jan 1, 1961

By F. N. Rhines, W. S. Pellini

In many of the otherwise well established alloy phase diagrams the solidus curves (temperatures at which liquid first appears upon melting) have not been located accurately, chiefly because the experimental techniques that have been most popular for determining solidus temperatures have been both cumbersome and subject to large errors. C. E. Homer and H. Plummerl have described a sensitive and at the same time a very simple technique for locating the solidus curves in a number of alloys of tin. Their method consists simply in noting the temperature at which a specimen of the alloy ruptures under the influence of a light bending force. Although this method is not new, it has been little used for this purpose in the past; nevertheless, it appears so attractive in its possibilities of speed, simplicity, and precision that the investigations presently to be described were undertaken to verify its merits. The redetermination of the solidus and eutectic temperatures of the lead-antimony system was employed as a medium of experimentation. New values obtained in this way are believcd to be sufficiently precise to warrant a revision of the currently accepted lead-antimony phase diagram (Fig. I). Determinations of the solidus of the lead-rich lead-antimony alloy series have been published by X. S. Dean2 and by E. E. Schumacher and F. C. Nix. Their points are represented in Fig. I. In their work the solidus was not located at antimony collcentrations greater than 2 per cent; the curve was presumed to meet the eutectic horizontal at an antimony concentration of about 2.5 per cent. In the present studies the solidus has been traced to 3.5 per cent, where the eutectic horizontal is intersected (Table I and Fig. I). Within the range investigated by Dean and by Schumacher and Nix the agreement with their values is good. H. Seltz and B. De Witt,4 on the basis of activity measurements, have calculated that the intersection of the solidus and the eutectic reaction horizontal should lie at 3.86 per cent of antimony. The following determinations of the eutectic temperature have been reported: Roland-Gosselin,5 228°C.; Ewen,6 228OC.; J. E. Stead,7 24g°C.; Campbell,8 228°C.; W. Gontermann,9 245' to 252°C.; R. Loebe,lo 245°C.; E. Heyn and 0. Bauer,ll 245°C.; H. Endo,12 250°C.; R. S. Dean,= 247' to 258°C.; E. Abel, O. Redlich, and J. Adier,13 245°C.; W. Broniewski and L. Sliwowski,14 250' to 252°C.; H. Seltz and B. De Witt,4 25o°C. A temperature of 247°C. appears to have been generally accepted in recent years; it is the value most frequently obtained by the method of cooling curves. Values below 247°C. have usually been obtained by inferior cooling-curve techniques; those above 250°C., by the method of heating

Jan 1, 1943

By W. S. Pellini, F. N. Rhines

In many of the otherwise well established alloy phase diagrams the solidus curves (temperatures at which liquid first appears upon melting) have not been located accurately, chiefly because the experimental techniques that have been most popular for determining solidus temperatures have been both cumbersome and subject to large errors. C. E. Homer and H. Plummerl have described a sensitive and at the same time a very simple technique for locating the solidus curves in a number of alloys of tin. Their method consists simply in noting the temperature at which a specimen of the alloy ruptures under the influence of a light bending force. Although this method is not new, it has been little used for this purpose in the past; nevertheless, it appears so attractive in its possibilities of speed, simplicity, and precision that the investigations presently to be described were undertaken to verify its merits. The redetermination of the solidus and eutectic temperatures of the lead-antimony system was employed as a medium of experimentation. New values obtained in this way are believcd to be sufficiently precise to warrant a revision of the currently accepted lead-antimony phase diagram (Fig. I). Determinations of the solidus of the lead-rich lead-antimony alloy series have been published by X. S. Dean2 and by E. E. Schumacher and F. C. Nix. Their points are represented in Fig. I. In their work the solidus was not located at antimony collcentrations greater than 2 per cent; the curve was presumed to meet the eutectic horizontal at an antimony concentration of about 2.5 per cent. In the present studies the solidus has been traced to 3.5 per cent, where the eutectic horizontal is intersected (Table I and Fig. I). Within the range investigated by Dean and by Schumacher and Nix the agreement with their values is good. H. Seltz and B. De Witt,4 on the basis of activity measurements, have calculated that the intersection of the solidus and the eutectic reaction horizontal should lie at 3.86 per cent of antimony. The following determinations of the eutectic temperature have been reported: Roland-Gosselin,5 228°C.; Ewen,6 228OC.; J. E. Stead,7 24g°C.; Campbell,8 228°C.; W. Gontermann,9 245' to 252°C.; R. Loebe,lo 245°C.; E. Heyn and 0. Bauer,ll 245°C.; H. Endo,12 250°C.; R. S. Dean,= 247' to 258°C.; E. Abel, O. Redlich, and J. Adier,13 245°C.; W. Broniewski and L. Sliwowski,14 250' to 252°C.; H. Seltz and B. De Witt,4 25o°C. A temperature of 247°C. appears to have been generally accepted in recent years; it is the value most frequently obtained by the method of cooling curves. Values below 247°C. have usually been obtained by inferior cooling-curve techniques; those above 250°C., by the method of heating

Jan 1, 1943

By A. Alonso, J. Daubenspeck

In the nickel extraction process at Nicaro, Cuba, dried and ground nickel bearing laterites are reduced at 1300-1400F in multiple-hearth furnaces. Nickel is leached from the reduced ore by aeration in an aqueous solution of ammonium carbonate. Nickel carbonate is precipitated from the liquor and calcined to yield nickel oxide. The following are the more important modifications of the Nicaro process since plant rehabilitation and expansion. Ten percent increase in tonnage was achieved without decreasing the fineness of the ore by minor mechanical modifications of the grinding plant. Another five percent increase in tonnage was attained by intentionally overloading the ore prepration and leaching circuits in an effort to control cobalt extraction. Modifications at the sintering plant allowed it to handle the entire output of the expanded plant. A fifty percent increase in leach liquor cooling facilities alone provided an increase in nickel production of five percent. Stronger fresh leach liquor for increased nickel washing efficiency was obtained through improved distribution of water to the ammonia absorption towers. Advantage was taken of the reduced calcine's capability to precipitate cobalt, and modifications in the leach liquor circulation provided controlled cobalt solubility with minimum harm to nickel extraction. Several process changes at the drying plant brought about a ten percent reduction in the fuel oil consumption at this pint. Controlled air addition to the reduction furnaces' upper hearths burned formerly wasted combustibles thereby reducing oil consumption by twenty percent. The nickel extraction process successfully emplayed on the extensive but lowgrade lateritic ores of Eastern Cuba at the U. S. Government owned Nicaro plant, has been previously described in various publications. The large mine and plant operated by the Nickel Processing Corporation, located on the northeastern shore of Oriente Province, have been recently expanded to a yearly capacity of about 50 million pounds of nickel. Essentially, the operation involves open pit mining of a limonite-serpentine ore mixture containing 1.3 to 1.4 percent nickel and 34 to 38 percent iron. The comparatively lumpy, wet (25 to 30 percent moisture) ore is first dried and ground prior to chemical treatment, to which the entire 7,000 tons per day feed must be subjected. In the initial chemical action the dried and ground ore is reduced with carbon manoxide and hydrogen at 1300-1400° in multiple-hearth furnaces. The resulting metallic nickel is selectively leached from the reduced calcine by aeration in an

Jan 1, 1961

By C. M. Moncrief, B C. Craft

A bentonite-clay drilling mud when treated with tetrasodium pyroarsenate underwent substantially the same reduction in viscosity and water loss as when treated with the complex phosphates. The complex arsenate showed a slightly higher reversion after heating; the other arsenates showed poor viscosity-reducing properties. Introduction During the past 10 years the chemical control of drilling mud has become of major importance in affecting the successful drilling and working over of wells. The desired properties of drilling mud have been well established, and in obtaining these characteristics there has developed a large market for viscosity-reducing chemicals. Viscosity reduction produced by humic acid, tannic acid, sodium silicate, sodium tannate, Calgon, and the complex phosphates has been described by Loomis, Ford, and Fidiam.l The effects Of treatment with complex phosphates and ammonium PolyPhosPhates on the rheological properties of muds were investigated by Fancher2 and the alkali vanadates have been described by Williams.3 Laboratory Investigations It is the purpose of this paper to point out the effects of arsenates in controlling the viscosity and gelling characteristics of a drilling mud. Viscosities and gel strengths were measured at room temperatures with a Stormer viscosimeter calibrated in centipoises and operated at 600 r.p.m. Water loss was determined at 80°F. with the Baroid low-pressure wall-building tester at a pressure of I00 lb. per sq. in. for 30 min. The hydrogen-ion concentration was measured with a glass electrode. The bentonite-clay suspensions were prepared in the laboratory and allowed to age several days before testing. Members of the Arsenic Group in the periodic Table include arsenic, antimony and bismuth, but this investigation was limited to arsenic. Phosphorus also occurs in Group V of the Periodic system and phosphorus and arsenic form many closely related compounds such as pH3 and AsH3, P2O5 and As2O5, H3PO4 and H3AS04 Samples of tetrasodium pyroarsenate were prepared by fusing c.p. disodium arsenate (Na2HA5O4.7H2O). According to Friend,' this re-forms the ortho-arsenate on dissolution in water. Sodium trihydrodiorthoarsenate was prepared as described by Mellor,5 from arsenic pen-toxide as follows: As2O5 + 3H20 -> 2H3AsO4 2H3AS04 + 3NaOH Na3H3(AsO4)2 .3H20 Sodium dihydrogen orthoarsenateWaHz-As04) was obtained by fusing together equivalent quantities of arsenious Oxide and sodium nitrate, dissolving the residue in water and allowing it to crystallize.

Jan 1, 1946

By C. M. Moncrief

A bentonite-clay drilling mud when treated with tetrasodium pyroarsenate underwent substantially the same reduction in viscosity and water loss as when treated with the complex phosphates. The complex arsenate showed a slightly higher reversion after heating; the other arsenates showed poor viscosity-reducing properties. Introduction During the past 10 years the chemical control of drilling mud has become of major importance in affecting the successful drilling and working over of wells. The desired properties of drilling mud have been well established, and in obtaining these characteristics there has developed a large market for viscosity-reducing chemicals. Viscosity reduction produced by humic acid, tannic acid, sodium silicate, sodium tannate, Calgon, and the complex phosphates has been described by Loomis, Ford, and Fidiam.l The effects Of treatment with complex phosphates and ammonium PolyPhosPhates on the rheological properties of muds were investigated by Fancher2 and the alkali vanadates have been described by Williams.3 Laboratory Investigations It is the purpose of this paper to point out the effects of arsenates in controlling the viscosity and gelling characteristics of a drilling mud. Viscosities and gel strengths were measured at room temperatures with a Stormer viscosimeter calibrated in centipoises and operated at 600 r.p.m. Water loss was determined at 80°F. with the Baroid low-pressure wall-building tester at a pressure of I00 lb. per sq. in. for 30 min. The hydrogen-ion concentration was measured with a glass electrode. The bentonite-clay suspensions were prepared in the laboratory and allowed to age several days before testing. Members of the Arsenic Group in the periodic Table include arsenic, antimony and bismuth, but this investigation was limited to arsenic. Phosphorus also occurs in Group V of the Periodic system and phosphorus and arsenic form many closely related compounds such as pH3 and AsH3, P2O5 and As2O5, H3PO4 and H3AS04 Samples of tetrasodium pyroarsenate were prepared by fusing c.p. disodium arsenate (Na2HA5O4.7H2O). According to Friend,' this re-forms the ortho-arsenate on dissolution in water. Sodium trihydrodiorthoarsenate was prepared as described by Mellor,5 from arsenic pen-toxide as follows: As2O5 + 3H20 -> 2H3AsO4 2H3AS04 + 3NaOH Na3H3(AsO4)2 .3H20 Sodium dihydrogen orthoarsenateWaHz-As04) was obtained by fusing together equivalent quantities of arsenious Oxide and sodium nitrate, dissolving the residue in water and allowing it to crystallize.

Jan 1, 1946

By Gerhard Derge

THE introductory paper1 of this series described the potential behavior of tin in sodium carbonate and bicarbonate solutions whose pH ranged from 8.4 to 11.2 and demonstrated that significant and reproducible results could be obtained by proper attention to experimental technique. In examining the corrosion of tin under such conditions, it is desirable to know the effects of anions, aside from carbonate, that are likely to be present in commercial materials packaged in tin. Therefore, in this paper the potential behavior of tin in carbonate solutions to which sodium fluoride, chloride, bromide, iodide, sulphate, nitrate, monobasic phos-phate, dichromate, perborate and acetate have been added will be described. For most of the additions, solutions containing 0.001 and 0.01 .moles of the added material were studied. The experimental procedure was exactly the same as that described in the first paper; the pH of the electrolyte was controlled by adjusting the ratio of carbonate to bicar-bonate as follows: pH 0.1 M NaHCO3 8.4 2 parts 0.1 M NaHCO3, 1 part 0.1 M Na2CO3 9.5 1 part 0.1 M NaHCO3, 2 parts 0.1 M Na2CO3 10.0 0.1 M Na2CO3 11.2 The reagents used were all of C.P. grade. The anions studied may be divided into three groups: (1) anions that had little or no effect upon the potential curves-sulphate, nitrate, and acetate; (2) those that helped to prevent corrosion at low pH only-fluoride, chloride, bromide, and iodide; (3) those that helped to prevent corrosion at high pH also-phosphate, perborate, and chromate.

Jan 1, 1939

By G. P. Marino

The "conductivity ", Kr, of a spherical void in a linear temperature gradient due to radiation is calculated by integration of the general expression for diffuse radiation between two gray surfaces of arbitrary orientation. The spherical geometry allows an exact evaluation of the phenomenon without resorting to up-proximate expressions for the radiant heat flux. The resulting expression for Kr is three quarters of the approximate value obtained by Loeb. IN the determination of the thermal conductivity of porous materials such as sintered UO2 and ThO2 fuel pellets, the magnitude of the thermal conductivity in the pores due to radiative heat transfer across the pore, Kr, may be important in assessing the total conductivity of the pellets. Loeb' has calculated Kr for various pore geometries by approximating the net flux of heat between two surfaces of temperature difference AT as 4eT~AT and obtained: K,=4yoet3odp [1] where a is the Stefan-Boltzmann constant, E is the emissivity of the radiating surface, To is the average absolute temperature of the region across which radiation occurs, dp is the largest dimension of the gap in the direction of heat flow, and y is a geometric factor. That is: y = 1 for laminar pores and cylindrical pores with axes parallel to the heat flow direction, y = 2/3 for spherical pores, y = /4 for cylindrical pores with axes perpendicular to heat flow direction. It was the purpose of this work to obtain an exact expression for K, in spherical pores by integration of the general expression for the net heat transfer between two incremental areas on the surface of a spherical pore. This procedure yields a value of Kr 3/4 of that obtained by Loeb. I) CALCULATION OF Kr Fig. 1 illustrates the general geometry which defines the problem. The total emissive power for a gray body is given by: E = EoT4 [2] where E is the radiated energy per unit area of the radiation surface per unit time, T is the absolute temperature, o is the Stefan-Boltzmann constant (o = 5.67 X lo- '' watt per sq cm-"K1), and E is the emissivity of the surface. Although Eq. [2] gives the exact expression for the total emissive power of any gray body, all practical problems involve the net exchange of thermal radiation between a body and surrounding bodies. The two major considerations in the solution of such problems are a) shape and relative position of the surfaces and b) the emissivities of the surfaces. In this work it shall be assumed that all incremental areas on a pore have the same emissivity and, further, that little or no reflection occurs (i.e., the radiation hitting a surface is either absorbed or transmitted). Thus, the solution of the stated problem requires only that consideration a be satisfied. Consider two incremental surface areas dA 1 and dA2 of the same material in a general orientation to one another. Let dAl be at temperature TI and dAz be at T2. Fig. 2 illustrates the geometrical parameters involved. That is, 71, is the normal of dA, n2 the normal of dA2, r the line connecting the centers of each area, 81 the angle between nl and r, and Q2 the angle between 7,2 and r. Using Eq. [2] and the Lambert cosine law of diffuse radiation it is easily shown that:293 WdAf- dA, = ecr T*------^fpi------" dAidA2 [ 3a 1 and

Jan 1, 1970