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By R. W. Fountain, M. Korchynsky

The precipitation phenomena occurring in cobalt-tantalum alloys have been investigated in the temperature range frm 500" to 1050°C by correlating the results of metallographic, X-ray, micro-and macrohardness, and electrical resistivity studies. The property andmacrohardness,changes were found to depend on 1) general precipitation, and 2) lamellar precipitation. Two new intermetallic phases have been identified: 1) a Co3Ta, a metastable ordered face-centered-cubic compound, and 2) a stable ß Co3Ta phase of hexagonal structure. In addition, the previously reported Co2Ta phase was found to exist in two allotropic modifications: the hexagonal MgZn,-type and the cubic MgCu2-type Laves phases. SINCE a large variety of structures can result as a consequence of the decomposition of a solid solution, predictions on the nature of property changes are difficult, if not impossible, to make. For any rational attempt to correlate properties and structures of a precipitation-hardenable alloy, a detailed understanding of the kinetics of decomposition and morphology of phase separation, as well as knowledge of phase relationships, appears to be prerequisite. Information of this type has been accumulated in the past for many alloy systems, both of theoretical and pastforpractical importance.1,2 Although the presence of intermetallic compounds has been reported in cobalt-base alloys,3 the amount of published information on precipitation-hardenable cobalt-base systems is very limited. A survey of the binary phase diagrams of cobalt indicates that cobalt-tantalum alloys might be of interest as typical of other cobalt-base systems in which Laves phases of the A,B type can be precipitated from solid solution. The present work has been undertaken, therefore, to study the kinetics and morphology of the precipitation reaction in this system and to establish a base for a correlation between the structural aspects and properties in this class of alloys. PREVIOUS WORK The only available phase diagram of the cobalt-tantalum system is based on the work of Koster and Mulfinger. According to these authors, the maximum solubility of tantalum in cobalt is about 13 pct (at 1275°C) and. less than 7 pct at room temperature. Tantalum additions lower the temperature of allotropic transformation of cobalt (about 420°C), and at 7 pct Ta, the high-temperature face-centered-cubic modification (ß cobalt) is retained at room temperature. The precipitating phase was originally designated as Co5Ta2 compound (55.2 pct Ta, about 1550°C melting point), but subsequent investigations by wallbaum5" identified this constituent as the A,B-type Laves phase. Wallbaum's data indicate that there are two modifications of this intermetallic compound: one richer in cobalt (Co2.2 Tao.8)of the hexagonal MgNi, type; and another of a higher tantalum content (Co2Ta) of the cubic MgCu, type. On the other hand, Elliott7 found that the cobalt-rich alloy (CO2.10,Tao.~l) was predominantly the cubic MgCu, type at 800°C and a mixture of both the MgCu2 and the hexagonal MgZn,-type Laves phases at 1000°C. At 1200°C, Elliott found only the MgZn, type while at 1400°C, he observed only the MgCu2 type. At the stoichiometric composition, Co2Ta, Elliott reported only the cubic MgCu2-type Laves phase in the temperature range of 600oto 1600°C. The precipitation of the cobalt-tantalum intermetallic compound is accompanied by a marked increase in hardness. According to Koster's4 data, the Brinell hardness of an 8 pct Ta-Co alloy increases from 230 to 340 upon short-time aging at 800°C. EXPERIMENTAL PROCEDURE The binary cobalt-tantalum alloys investigated contained 5, 10, and 15 pct Ta. The range of tantalum additions was thus slightly broader than the reported minimum and maximum solid solubility limits of tantalum in cobalt (7 and 13 pct, respectively)4 The alloys were vacuum-induction melted in a magnesia crucible using cobalt rondelles and technically pure tantalum sheet as raw materials. Deoxidation of the melt was accomplished with carbon, and the chemical analysis of the alloys is given in Table I. The effect of isothermal aging treatments on the progress of precipitation was studied on samples cut from cast ingots. These samples were solution treated for 2 hr at 1250°C and water-quenched. Aging was conducted in the temperature range from 500" to 1050°C for periods between 15 min and 1000 hr and followed by water-quenching. To prevent contamination from the atmosphere, all samples were sealed in evacuated Vycor or quartz tubes for heat-treatments. For solution treatment, argon at 0.2 atmospheric pressure was introduced prior to sealing of the capsule to prevent collapse at high temperature, and titanium sponge was placed at one end of the capsule to act as a getter. MACROHARDNESS The effect of aging on Vickers hardness (Dph) of

Jan 1, 1960

By DIFTIGIHT E. WOODBRIDGE

(Glen Summit Meeting, June, 1911,) DURING April, May, and June, 1910, I was in charge of an examination of the greater part of the Moa iron-ore area in Oriente Province, Cuba, on the north coast, near the east end of the island. My instructions, on arrival at the properties, were to check former estimates of tonnages and grades, and to re-examine the ore comprised in claims covering 44,727 acres. This work included .the running of lines dividing the properties into co-ordinate planes, the boring of many thousand feet of holes spaced at the intersections of these co-ordinates, the taking of samples of the ore penetrated, the analysis of these samples for their various constituent minerals, and the determination of the results as to tonnages, depths, and grades, both for individual properties and for the entire group. Each section of every one of the thousand holes drilled was to be compensated for depth and grade with every other, a series of simple arithmetical calculations of no slight magnitude, the mere mechanical labor of which consumed much time, but finally resulted in giving a complete average of all the essential facts for the entire area of 18,000 hectares. Had it not been for the more than willing, active, and able co-operation of the officers of the Spanish-American Iron Co., from Charles F. Rand, President, and Jennings S. Cox, General Manager, down to the most humble water-carrier, the work would have consumed far more time than it did. Papers prepared by others, and to which my present paper may be considered an addendum, elucidate, more fully than I could hope to do, the origin and geological character of these ores. I will confine myself to the situation, method and expense of exploration, and to probable courses of development and mining, with some attention to the cost of the ore delivered in the United States.

Mar 1, 1911

THE Institute assembled in the rooms of the Geographical Society, Cooper Union, at 8 o'clock P.M., February 24th, 1874. President Barnard, of Columbia College, delivered an address of welcome, to which President Raymond responded. The Council then presented the following names, duly indorsed for election as members and associates. The gentlemen named were unanimously elected. *Bullock, M. C., - New York. †Burke, M. D., - Cincinnati, Ohio. *Burt, M. W., -Wheeling, W. Va. †Cameron, J. G. M., - New York. *Canfleld, Frederick A., - Dover, N. J. *Chandler, Prof. C. F., - New York. *Clayton, J. E., - Salt Lake City. †Colton, C. A., - New York. *Cooke, Prof. George H., - New Brunswick, N. J. *Cooper, Edward, - New York. *Dahlgren, C. B., - Mazatlan, Mexico. †Dutton, Capt. C. E., - Washington, D. C. *Eurich, E. F., - New York. †Fuller, H. L., - Woodside, Luzerne County, Pa. †Hamilton, S. Jr., - New York †Harnickell, A., - New York. *Hearne, F. J., - Wheeling, W. Va. *Hill, Samuel W., - Marshall, Mich. *Hulbert, Edward J., - Houghton, Mich. *Hunt, R. W., - Troy, N. Y. †lhlseng, M., - New York. *Iselin, Henri, - New York. *Janney, Morris P., - Pottstown, Pa. *Jenney, Frank B., - Brooklyn, N. Y. *Jenney, Walter P., - Brooklyn, N. Y. †Joy, D. A., - New York. *King, Clarence, - New York. *Kittoe, E. F., - Charleston, S. C. †Lawrence, Robert,. - New York. *Locke, J. M., - Cincinnati, Ohio. *McCormick, Henry, - Harrisburg, Pa. * Members. † Associates.

Jan 1, 1874

Organization Place Date 1919 Automotive Engineers New York, N. Y. Feb. 4-6 American Institute of Mining Engineers New York, N. Y. Feb. 17-20 New England Association of Gas Engineers Boston, Mass. Feb. 19 American Institute of Electrical Engineers New York, N. Y. Feb. 19-21 National Society for the Study of Education Chicago, Ill. Feb. 25-28 American Railway Engineering Association Chicago, Ill. Mch. 18-20 American Electrochemical Society New York, N. Y. Apr. 3-5.

Jan 2, 1919

By Paul Gordon

The distribution coefficient, k, of interest in zone refining is generally defined as the ratio of the solid to the liquid solubilities of one element in another at the normal melting point of the solvent. In practice, distribution coefficients are frequently calculated from solubilities at temperatures well below the melting point of the solvent, e.g., at a eutectic temperature. This is done because of the general lack of accurate data on the liquidus and solidus curves in most phase diagrams. The practice is equivalent to assuming that the liquidus and solidus curves are straight lines in the temperature range between the melting point of the solvent and the temperature at which data for the solubilities are known. It is recognized that the k values so derived may be in serious error; we have found evidence in recent zone-refining operations that a case in point is silicon in aluminum. The phase diagram found in the literature for silicon in aluminum indicates a eutectic on the aluminum-rich side at 12.5 at. pct Si and at 577°C,1 and a solid solubility of silicon in aluminum at this temperature of 1.59 pct.2 It also shows the liquidus and solidus as nearly straight lines from 577°C to the melting point of aluminum (660°C)1,2 The k value obtained from this data is 0.13. This is almost exactly the same as the k value (about 0.14)' obtained in a similar way for copper in aluminum. Yet we have found by mass-spectrograph analyses* of three bars of zone-refined aluminum that copper is efficiently removed from aluminum by zone refining but silicon is not. Two of the three bars of aluminum were zone-refined in our laboratories, the other in the laboratories of AIAG Metals, Inc. The former two bars, designated bars PG2 and PG3, were 30 in. long by 1 in. in diameter during refining; each was processed in a high-purity graphite boat* and kept under refining stage of the process consisted of thirty unidirectional zone traverses at rates of about 1 to 2 in. per hr, with a zone length of 1 to 2 in. At approximately the middle of the refining period a 6-in. piece of the impurity-laden finishing end of the bar* was cut off and replaced with new start- ing material. Following refining, the purest 20-in. section of the bar (obtained by discarding approximately 2 in. of the starting end and 8 in. of the finishing end of the bar) was leveled and then analyzed. The AIAG bar was 16 in. long and about 1.2 in. in diameter; it was purified by eight passes of a 2-in. zone at a rate of 1.6 in. per hr, the bar being contained in a sintered alumina boat lined with loose alumina powder of the highest purity. Data for the silicon and copper contents of the three refined bars are given in Table I. Derived data for the efficiencies of the zone-refining operations are listed in Table 11. It is clear from these two tables that the copper is removed much more efficiently—by a factor of 10 to 50 times—from aluminum during zone refining than is silicon. For example, in bar PG3 the thirty zone passes reduced the copper content from 10 to 0.02 ppm, i.e., by 500 times, whereas the same treatment lowered the silicon content by only a factor of about 16. It seem virtually certain, therefore, that the distribution co efficient, k, for silicon in aluminum is well above that for copper and is very likely not much below unity. This also implies that the solidus line on the aluminum-rich side of the A1-Si phase diagram is very probably appreciably curved near the aluminum melting point since the phase-diagram data indicate such curvature is unlikely in the liquidus.

Jan 1, 1965

By H. M. Otte, A. L. Esquivel

A new leasl-squares method is Presented for determining lattice parameters of hexagonal or tetragonul structures. The method is adapted for use on electronic computers and involves a reiterative procedure. The correction factor employed raries linearly with the lattice parameter, a (determined from the Brag, angle). In contrast, Cohen's method and recent modifications of it use a correction factor that varies incersely as the squure of the lattice paramneter, a. While the recent modifications attempt to improve the precision of the extrapolated lattice parameter, a, (or-cu). by stressing the importance of the weighting factor. the present approach emphasizes the need for choosing the correct extrapolation function. A comparison between the present method (the Linear method) and Cohen's method indicates that the Linear method may be more appropriale in certain cases. through a priori no critertion appears to he available for making a chorce between the methods. The size of hexagonal and tetragonal crystal lattices is determined by two parameters, a, and c,. Although in principle the two lattice parameters can be determined independently from reflections for which h - k = 0 and 1 = 0, respectively, in practice this may be inconvenient (because of the angular positions at which these reflections may occur) or not easily possible (because of low intensity). Furthermore, if a high precision or accuracy is required, the limited number of reflections of this type available, particularly in the high-angle region, is not sufficient for the necessary corrections (mainly due to absorption) to be determined with accuracy. Several methods1-7,11-13 have been proposed employing all reflections, to obtain the optimum values, a. and co, either by a trial and error procedure or a least-squares fit. Of the latter method, cohen's5 is the best known one since it provides explicit expressions for the optimum a. and c,. However, Cohen's method is only strictly valid if an extrapolation function is used that varies linearly with l/a2 or lie2 (see Section 3), a requirement that does not appear to be generally appreciated. On the other hand, all the better known and more widely used A recent trial and error method was proposed by Massalski and King8,7 who computed extensive auxiliary tables of axial ratios vs the functions A = [(4/3)(h2 + hk +k2) + l2+(a/c)2] and C = A(c/a)2 used in computing a and c values from the observed Bragg angles. These values of a and c were then plotted against a function which permitted linear extrapolation. As a criteria; for the "optimum" values, Massalski and King rely upon a visual fitting of the line through points representing reflections of low 1-index points to compute the extrapolated value of ao and high 1-index reflections to obtain CO. The successive computations and graphical plotting required to reach the "optimum" value are quite lengthy and tedious even on a desk calculator and no quantitative assurance is obtained of having in fact selected the optimum value.* If the method of Massalski and King is used on an electronic computer, then their published tables become redundant and a least-squares fit becomes a natural selection for the choice of optimum values. Such an approach will be called the Linear method. For work now in progress on the effect of certain physical variables on the lattice parameters of hexagonal crystals, it has become essential to determine the confidence limits of small changes in the lattice parameters. Since extrapolation functions that varied linearly with a and c actually also appeared to vary linearly with l/a2 or l/c2 when tested against published as well as our data, a comparison of Cohen's method and the Linear method was considered desirable (Sections 3 and 4). For the latter method an electronic computer was required since a reiterative procedure to obtain the optimum ao and co values had to be employed. The purpose of this paper is to describe the principles of the Linear method, illustrate its application, and compare it with Cohen's method. 1) THE LINEAR METHOD The standard practice in obtaining the lattice parameters in the Debye-Scherrer method is to

Jan 1, 1965

For the year ending February, 1919 PRESIDENT SIDNEY J. JENNINGS NEW YORK, N. Y. PAST PRESIDENTS L. D. RICKETTS, NEW YORK, N. Y. PHILIP N. MOORE ST -Louis, Mo FIRST VICE-PRESIDENT C. W. GOODALE, BUTTE, MONT.. TREASURER GEORGE C. STONE, NEW YORK, N. Y. SECRETARY EMERITUS ROSSITER W. RAYMOND, NEW YORK, N. Y.

Jan 6, 1918

The Institute assembled in the rooms of the Geographical Society, Cooper Union, at 8 o'clock P.M., February Nth, 1874. President Barnard, of Columbia College, delivered an address of Welcome, to which President Raymond responded. The Council then presented the following names, duly indorsed for election as members and associates. The gentlemen named were unanimously elected. *Bullock, M. C.,. ., . New York. Burke, M. D.,.... Cincinnati, Ohio. *Burt, M. W.,.....Wheeling, W. Va. Cameron, J. G. M.,. ..'New York. *Canfield, Frederick A,,. .. Dover, N. J. *Chandler, Prof. C. F.,. .. New York. *Clayton, J. E.,. .. . Salt Lake City. Colton, C. A,,.... New York. *Cooke, Prof. George H.,. . New Brunswick, N. J. *Cooper, Edward,.... New York. "Dahlgren, C. B.,.... Mazatlan, Mexico. Dutton, Capt. U. E.,. .. Washington, D. C. *Eurich, E. F.,.... New York. Fuller, H. L.,.... Woodside, Luzerne County, Pa. Hamilton, S. Jr.,.....New York: Harnickell, A,,.,.. New York. *Hearne, F. J.,. .. . Wheeling, W. Va. *Hill, Samuel W.,.... Marshall, Mich. *Hulbert, Edward J.,. . Houghton, Mich. *Hunt, R. W.,.....Troy, N. Y. Ihlseng, M.,.....New York. "Iselin, Henri,.... New York. *Janney, Morris P.,. ..Pottstown, Pa. "Jenney, Frank B.,. .. . Brooklyn, N. Y. *Jenney, Walter P.,... Brooklyn, N. Y. Joy, D. A.,.....New York. *King, Clarence,.... New York. *Kittoe, E. F.,....Charleston, S. C. Lawrence, Robert,.... New York. *Locke, J. M.,..... Cincinnati, Ohio. *McCormick, Henry,. .. Harrisburg, Pa.

OFFICERS AND DIRECTORS For the year ending February, 1935 PRESIDENT AND DIRECTOR HOWARD N. EAVENSON PITTSBURGH, PA. PAST PRESIDENTS AND DIRECTORS SCOTT TURNER WASHINGTON, D. C. FREDERICK M. BECKET NEW YORK, N. Y. VICE-PRESIDENT, TREASURER AND DIRECTOR KARL EILERS NEW YORK, N. Y. VICE-PRESIDENTS AND DIRECTORS EUGENE MCAULIFFE OMAHA, NEB. PAUL D. MERICA NEW YORK, N. Y. HENRY KRUMB SALT LAKE CITY, UTAH EDGAR RICKARD NEW YORK, N. Y. LOUIS S. CATES NEW YORK, N. Y.

Jan 1, 1934

J. E. JOHNSON, JR., New York, N. Y. (communication to the Secretary*).-The discussion of Mr. Henrich's paper took place at a meeting from which I had the misfortune to be absent, and has just come to my attention. I do not wish to let the subject pass without contributing to it a little information which has come into my possession. In 1912, I published a brief note in the Transactions on The Effect of Alumina in Blast-Furnace Slags, giving in tabular form three typical slags used in iron blast-furnace practice, one of them the high alumina slag of, which Professor Richards speaks. That table is reproduced herewith. TABLE 1.-Composition of Slays. 1 3 3 4 5 6 7 CaO by Neutral Ratio Ratio Ratio Al2z03, SiO2, Differ- Substan- Cat Ca0 a A1203 Ratio Per Per ence, ces, CaO Cent. Cent. Per Per Al2O3 + Sioz Sit: SiO2 Cecil_ Cent. Virginia practice 6.5 36.0 54.0 3.5 1.27 1.6S 1.50 Lake-ore practice 13.5 33.0 50.0 3.5 1.08 1.92 1.51 Special experiment... 36.0 24.7 36.8 3.5 0.59 2.90 1.44 It supplies what seems to me convincing evidence that, for the purposes of the iron blast furnace, alumina can be regarded only as a neutral substance, dissolving in the slag and materially altering its viscosity, but not affecting its chemical activity. In subsequent experience with charcoal furnaces, I found the same rule to hold; that the chemical effect of alumina could be disregarded, providing the ratio of the lime and magnesia to the silica were kept constant. This is exactly the experience which Messrs. Dwight and Mathewson had in copper- and' lead-smelting furnaces. I have never seen any evidence or argument adequate to support the contention of Professor Richards-that the alumina acted as a base in the charcoal iron furnace and as an acid in the coke furnace, and that the function of alumina in iron-furnace slags is inherently different from that in copper- and lead-furnace slags-and I am compelled to differ absolutely with his conclusions in that respect.

Jan 9, 1917

By R. G. Charles, E. A. Gulbransen, S. Barnartt

KINETICS of the reaction of zirconium with pure oxygen at elevated temperatures have been studied by several workers for periods of time up to 6 hr.1-1 In two cases,3-4 . the experimental values of oxygen uptake, w, as a function of time, t, were best fitted to the parabolic rate law w2 = kPt + constant. In others,3,4 the cubic rate law w3 = kot + constant, showed better agreement. The most recent data of Gulbransen and Andrew4 indicate that the choice between the parabolic and cubic laws for empirical representation of the data will often be arbitrary. This is particularly true if the first few minutes of the reaction with a clean zirconium surface is attributed to a different oxidation mechanism, for deviations from either rate law were found primarily during the initial period. Thus, the kinetics of this reaction have been too uncertain to permit safe extrapolation to oxidation periods of practical interest (many hundreds of hours). The data to be described are of interest, for they indicate that the cubic rate law applies over long oxidation times. The reaction of zirconium with oxygen at 1 atm pressure was followed at 350" and 450°C for 500 and 200 hr, respectively. Abraded test specimens of pure zirconium sheet' 3.0 X 2.0 X 0.012 cm in size were oxidized by the procedure previously described,3 which included periodic cooling to room temperature for weighing. The surfaces were polished to a 4/0 finish using polishing paper wet with kerosene, then wiped with petroleum ether and washed in redistilled acetone. Fig. 1 shows plots of log ? vs log t. Each curve represents the average of duplicate measurements, and deviations from the average were generally less than 3 pet. The cubic rate law (slope = 1/3) is closely followed. The rate constants, 5.2, x 10 -6 and 2.4, X 10- (mg cm-2)3 per hr at 350" and 450 oC, respectively, are plotted as log k, vs 1/T in Fig. 2, together with cubic constants calculated from the data of Gulbransen and Andrew4 for abraded specimens from the same lot of zirconium. Their data refer to runs of 6-hr duration at a pressure of 0.1 atm 0 and under conditions of uninterrupted heating. In spite of these differences, the latter data yield a straight line which appears to apply equally well to the new extended time data. The energy of activation for the oxidation process, calculated from the slope of this line, i.s 38 keal per mole. This may be compared with the value of 47 keal per mole found by Belle and Mallett3 at higher temperatures. It may be concluded tentatively that extrapolation of short-term oxidation data for zirconium to obtain the long-term behavior is best done through the cubic equation ?3 = kpt + constant. References ' E. A. Gulbransen and K. F. Andrew: AIME Trans., 1949, vol. 185, p. A.515; JouRNal OF Metals, August 1949. 'D.p. Cubicciotti Journal Amer Chemical August1949.Soc., 1950, Vol. 72, P. 3 V. Belle and M. W. Mallett: Joulnal Electro chemical Soc., 1954, ' E. A. Gulbransen 339.and K. F. Andrew: Oxidation of Zirconium Between 400" Gulbransenand 800'C.and AIME Trarzs.. 1957, vol. 209, p. 394; JOUR-Nal of Metals, April 1957. IS Barnartt, B G. Charles, and E. A. Gulbransen: Oxidation of 50 weight pet uranium-zirconium alloy, Journul Electrochemical SOC., 1957, vol. 104, p. 218.

Jan 1, 1959

By Suresh P. Babu, Joseph W. Leonard

The ultimate objectives of comminution should be to reduce material to some specified size while producing a minimum of undersize or fines, with less power, higher throughputs, and with more compact machinery. Attempts to achieve these objectives have been only partially successful, since gains in some areas are achieved at the cost of concessions in other areas. An example of some of these trade-offs can be found in the closed circuit crushing operations of the anthracite and crushed stone industry where, in order to produce a minimum of unprofitable fines, unfavorable concessions must be made in the size of the crushing facility where 2 or more crushing stages are interphased by 2 or more screening operations. This paper discusses experiments with a new process which attempts to achieve some, if not all, of the comminution objectives in a single pass operation without undesirable concessions; or, at the very least, to achieve more than is possible with systems in use today. These objectives are sought by use of water-flushing to enhance comminution. The crushing of coal and other minerals is a mature technology that is long overdue for a careful re-examination. Crushing of coal is generally achieved through the use of rotary breakers and roll crushers. Water-flushing, as envisioned here, appears to have potential application in the following areas: 1) For primary raw coal crushing or for secondary crushing of rotary breaker products. 2) For use as a size reduction and/or concentrating step for crushing coal mine refuse from present production or from existing refuse dumps. 3) For possible future application in underground preparation interphased with continuous mining machinery. Size reduction with conventional methods is known to be an inefficient operation when the increase in surface energy of the material crushed is compared with the input energy. A simple breakdown of the energy consumption in size reduction, given by Orr, is shown in [Fig. 1]. It is believed that most of the energy supplied is lost in the form of interparticle friction.2 Hence, the removal of fines immediately after their formation or the implementation of steps to prevent their formation, based on reduced friction, will reduce the energy requirements of the communition operation.3 A detailed discussion of the mechanism of size reduction is available in other literature.3-5 Even though the closed circuit crushing operation is designed to carry the fines away from the crushing zone, it is still inadequate for instantaneous removal of fines. The present investigation advocates the use of a flowing liquid medium to remove the crushed product immediately after size reduction. Unlike the wet-grinding methods, no constraints are required for the liquid flow rate, and, also, the liquid medium can be used in primary crushers like jaw crushers, hammer mills,

Jan 1, 1978

By A. Madrazo

The Standing-Katz method for predicting liquid densities of reservoir fluids has been tested using experimental data of 154 bottom-hole or recombined reservoir fluid samples. New pressure- and temperature-correction curves for the Standing-Katz type correlation are presented which improve the accuracy of prediction. INTRODUCTION The present study was undertaken to investigate the known methods of determining liquid densities and to select one of them which might yield a better correlation if additional data were employed. An appropriate correlation would incorporate the following characteristics: (1) ease of handling in the computations, (2) results within engineering accuracy and (3) data easily accessible. After careful investigation of the different methods, the Standing-Katz correlation1 appeared to have these characteristics. The Standing-Katz correlation for liquid densities of hydrocarbon systems is based upon limited data. The original work, which employs apparent densities for methane and ethane, was based on data of 15 saturated crude oils in equilibrium with natural gas. Therefore, a test of the correlation using additional experimental data would serve either to validate the Standing-Katz correlation or to form a basis for corrections if such were necessary. PROCEDURE AND GRAPHICAL SOLUTION The data of 154 bottom-hole or recombined reservoir fluid samples were employed to calculate the densities at 14.7 psia and 60°F by the method described in Table 1. Volume contributions for methane and ethane were assigned from the pseudo liquid density plot (Fig. I), but volume contributions for N2, CO2 and HzS were not considered. The densities computed at reference conditions of 14.7 psia and 60°F were then elevated to their respective temperatures and pressures by the use of the correction curves proposed by Standing.' The percentage differences between the experimental values and the calculated values were determined; these samples were grouped into temperature, pressure and density ranges to determine a possible trend. It appeared that, at temperatures above 160°F, the calculated density values were consistently larger than the experimental density values; however, no obvious trend was found for the density and pressure ranges. There is a relationship between the pressure-correction and temperature-correction curves. This relationship, embodied in the temperature-correction curve, can be expressed as follows. The experimental densities of 125 samples above their bubble points were known. From these isothermal data, it was possible to determine an experimental-density difference between two pressures; and (from Fig. 2*), a calculated density difference between the same two pressures was determined. The relative effect of temperature must be considered in the calculated-density values. The effect of temperature can be determined by entering Fig. 3* at the two densities in consideration and obtaining the change in density at constant temperature. This change, or delta density, must be added

By Nicholas J. Grant, Robert H. Kane, Bill C. Geissen

The platinum-rich section of the Ta-Pt Phase diagram was worked out by metallographic and X-ray techniques, using twenty alloys; solidus temperatures and solid solubilities were determined. Besides s phase, four intermediate stoi-chiometric phases were found: TaPt (high-temperatzrre phase, structure unknown); TaPt2 (ortho-rhomhic, new type); a TaPt3 (orthorhombic, TiCu3 type); ß TaPf3 (monoclinic, new type). TaPt2 and TaPt3 melt congmentlv; two eutectic, two beritec-tic, and one eutectoid reactions occur in the inuestigated range. THE Ta-Pt system was examined as part of a study of the phase diagrams and the intermediate phases of niobium and tantalum with Group VIII transition metals. Since the main scope of this work was the relation among the ordered close-packed phases occurring in the concentration range from AB to AB3 (A = Nb, Ta; B = Pd, Pt, and so forth), only the platinum-rich side of the diagram was worked out thoroughly, while spot checks were made to determine the approximate outline of the tantalum-rich portion. The system has not been thoroughly treated in the literature; Greenfield and Beck1 in their survey of refractory metal intermediate phases found a o phase between -18 and 37 at. pct Pt which coexists at higher platinum concentrations with an unidentified intermediate phase. Browning2 worked on the range between 55 and 100 at. pct Pt; however, this preliminary study did not cover temperatures >1500°C, and included no conclusive crystallo-graphic data. More recently, a study of the platinum-rich section of the Ta-Pt system has been carried out by Ray,3 while Hartley, Parsons, and steedly4 have studied the tantalum-rich section. The crystal structures of TaPt2, a TaPt3, ß TaPt3, and others have been reported in abstracted form by Giessen and Grant.5 EXPERIMENTAL METHODS The methods of alloy preparation and processing and of the metallographic and X-ray procedures follow very closely those described by Ritter, Giessen, and rant' for other refractory metal-noble metal systems, and will not be repeated except where significant differences exist. Starting materials were: tantalum rod of 99.95 pct purity, supplied by National Research Corp., and platinum sponge 99.9 pct, supplied by The International Nickel Co. An oxygen analysis of the tantalum rod showed 30 ppm O; other impurities were C, N, Si, Nb, Mo, none of these exceeding 50 ppm, and 100 ppm W. Homogeneous buttons were readily prepared as follows: ingots of 5 g were weighed and arc-melted under welding grade argon, followed by two remelts after inverting the button. Between 40 and 100 at. pct Pt, weight losses during the first melt rarely exceeded 0.1 pct, in which case the alloy was rejected, and were nil on subsequent remelts. Since the vapor pressure of platinum far exceeds that of tantalum, the small evaporation loss could be assumed to consist of platinum; therefore, a corresponding amount of platinum was added on the second melt. Since it was confirmed on pure tantalum samples that no weight gain through oxygen or impurity pickup occurs (see Ref. 71, it could be assumed that the uncertainty in the composition did not exceed ±0.1 at. pct for the range 40 to 100 at. pct Pt. For the four control melts from 0 to 40 at. pct Pt, an error of ±0.5 at. pct was calculated. Microscopic examination of the whole buttons after melting showed no inhomogeneity other than local coring. This was eliminated by a homogenization heat treatment. A total of twenty-three alloys were prepared. Heat treatments were carried out in a tantalum

Jan 1, 1965

By R. E. Lamborn

A summary of oil and gas development in Ohio for 1935 must necessarily be brief. As attention of the state government to the oil and gas industry has never included the collection and compilation of statistics on production, either by producing sands, by counties, by fields, or for the state as a whole, such information as requested in Table 1 of this symposium is impossible to secure for this state. In the absence of production data chief attention must be directed to drilling activity for the year. Information such as can be compiled from various sources, including weekly drilling reports to operating companies and trade journals, is given in the following paragraphs with the realization that the data may not be complete in all its details. Drilling Activity by Fields Drilling activity during 1935 was similar to the preceding year in , that the major operating companies were generally content to drill lease-requirement and offset wells and in that comparatively little effort was made to discover new pools. A compilation of completions recorded in weekly reports to drilling companies and in trade journals show 1022 tests completed for the year in 53 counties of the state. Of this total number, 653 wells were commercial producers and 369 were classed as dry holes. Production was secured in 40 counties from formations ranging in depth to 5700 ft. and ranging in age from Middle Ordovician to upper Pennsyl-vanian. From the standpoint of new production for the year, the most important sands are the Clinton of Silurian age, the Berea of Mississippian age and the Shallow sands of Mississippian above the Berea and of Pennsylvanian age. Trenton Sand Field Production in the field of Trenton sand, which originally included parts of 15 counties in northwestern Ohio, is now on the decline. Seventy-three completions were reported in this field during 1935, of which 33.8 per cent were dry holes. Activity centered in Allen County with 12 completions, two of which were dry holes; in Hardin County with 11 producers; and in Wyandot County with 12 producers and 2 dry holes.

Jan 1, 1936

By R. E. Lamborn

A summary of oil and gas development in Ohio for 1935 must necessarily be brief. As attention of the state government to the oil and gas industry has never included the collection and compilation of statistics on production, either by producing sands, by counties, by fields, or for the state as a whole, such information as requested in Table 1 of this symposium is impossible to secure for this state. In the absence of production data chief attention must be directed to drilling activity for the year. Information such as can be compiled from various sources, including weekly drilling reports to operating companies and trade journals, is given in the following paragraphs with the realization that the data may not be complete in all its details. Drilling Activity by Fields Drilling activity during 1935 was similar to the preceding year in , that the major operating companies were generally content to drill lease-requirement and offset wells and in that comparatively little effort was made to discover new pools. A compilation of completions recorded in weekly reports to drilling companies and in trade journals show 1022 tests completed for the year in 53 counties of the state. Of this total number, 653 wells were commercial producers and 369 were classed as dry holes. Production was secured in 40 counties from formations ranging in depth to 5700 ft. and ranging in age from Middle Ordovician to upper Pennsyl-vanian. From the standpoint of new production for the year, the most important sands are the Clinton of Silurian age, the Berea of Mississippian age and the Shallow sands of Mississippian above the Berea and of Pennsylvanian age. Trenton Sand Field Production in the field of Trenton sand, which originally included parts of 15 counties in northwestern Ohio, is now on the decline. Seventy-three completions were reported in this field during 1935, of which 33.8 per cent were dry holes. Activity centered in Allen County with 12 completions, two of which were dry holes; in Hardin County with 11 producers; and in Wyandot County with 12 producers and 2 dry holes.

Jan 1, 1936

By J. C. Todd

The volume of air needed to move the combustion wave through each acre-foot of the reservoir is a very important quantity for engineering economic analyses. A new method, which involves backflowing the injection well, has been developed for determining the air requirement .for the forward combustion thermal pilot in the Delaware-Childers field. The method depends on measurement of the total volume of air injected and measurement of the pore volume in the zone swept out by the combustion front. The basic premise of the method is that the pore volume of the swept zone contains air, while the formation around this zone contains flue gas, oil and water. The pore volume of the swept zone is determined by blowing down the pilot section of the formation through the injection well after the pilot is shut down. Oxygen balance is used to differentiate between air from the swept zone and flue gas from the surrounding formation. Data indicate that air'is produced from the swept zone by relatively efficient miscible displacement by the flue gas. The pore volume occupied by the air in the swept zone is determined by simple PVT relationships. The average temperature of the swept zone is calculated by heat balance from the total amount of heat generated during the pilot and losses to the surrounding formation. The new method was applied successfully at the conclusion of the pilot in the Delaware-Childers field; the air required for the reservoir conditions involved was calculated to be 19.2 MMscf/acre-ft of reservoir swept. INTRODUCTION One of the most important pieces of information to be found from a forward combustion pilot is the air requirement; that is, the volume of air needed to move the combustion wave through each acre-foot of the reservoir. Compression costs per barrel of oil recovered, which are a direct function of the air requirement, are a large portion of the expenses incurred in the thermal recovery process. Thus, the profitability of thermal recovery depends largely on the air requirement, which is a measure of the amount of fuel deposited and burned in the thermal recovery process. Several attempts have been made to correlate crude oil properties with fuel deposition and, hence, air requirement.l*2 Other attempts have been made by our laboratory to find the air requirement by material balance, gravity survey, pressure transient analysis,3 magnetic survey and the poten-tiometric model. Better methods are needed to predict more accurately the economics of fieldwide application of the process. Another method of finding the air requirement consists of operating a pilot thermal project for several years. This is followed by an extensive coring program to define the volume swept by the combustion wave. The air requirement is found from the total injected air divided by the volume of the swept region found from the coring operation. This method is costly; an adequate coring program usually costs several hundred thousand dollars. A thermal pilot was operated in a watered-out portion of the Delaware-Childers field, Bartlesville sand, from Nov., 1960, until May 3, 1965. One of the primary purposes of this pilot operation was to determine the air requirement for economic calculations which determine the advisability of expanding the project to the entire 128,000 acre-ft field. Barnes4 has described the result of this pilot operation,, including calculation of the air requirement from limited coring data. The value obtained, as calculated, was 15.8 MMscf/acre-ft. One purpose of this report is to describe a new method of finding the air requirement from a thermal pilot operation. A second purpose is to describe the application of this method to the Delaware-Childers thermal pilot. THEORY AND DESCRIPTION OF THE METHOD The combustion zone in the forward combustion process is propagated from injection w producing

Jan 1, 1970

By B. W. Gonser

SOFT solders are used principally in the automotive, can-making, building construction and electrical industries, but their field of usefulness extends well beyond these principal users to a vast list of miscellaneous applications where metal joints are required. The most common soft solders and the only ones considered in this discussion are those com-posed of lead and tin, with or without various relatively small percentages of impurities or additions. A small amount of antimony is often pur-posely added. As an indication of the importance of these lead-tin solders, 8620 long tons were consumed in 1934 in the U.S., and during most of 1935 from 900 to 1000 long tons were used each month. A great many factors influence the properties of joints made with soft solders. Fluxes and the fluxing procedure used to prepare the surfaces to be joined in order to give a true metal-to-metal contact are among the most important of these factors. The temperatures used, cleanliness of the work and general soldering technique have their effect, but when results are unsatisfactory they are usually attributed to the metallic solder itself and the raw materials from which it is made. Some-times criticism of the solder is justified. The wrong composition may be chosen for a given job, impurities may be present that ruin certain desired qualities, or uniformity may be lacking. A solder may even be looked upon with suspicion because of its ancestry, regardless of its true composition and behavior. To clarify the effect of slight differences in composition as found in commercially refined solders, a comparison of properties of solders grouped according to their origin has been undertaken. This investigation seeks to give practical information on the proper-ties of tin-lead solders produced from virgin metals, from commercially

Jan 1, 1936

By E. A. G. Colls

IN all branches of the chemical industry, corrosion plays a very costly part unless it is suitably com-batted, and as a result it is probably correct that chemical and design engineers are more corrosion conscious in the field of chemical industry than in others. Most metals occur in nature in combination with other elements. The refined or reduced state to which man converts them for his use, by removing the combining elements, leaves them in an unstable condition. Therefore in most of the media to which the metals are exposed they are constantly combining with the constituents of their environment, or in other words they are continually being corroded. Similarly, nonmetallic materials are corroded by undergoing chemical change. The rate at which corrosion takes place varies widely from metal to metal and medium to medium. In practically all cases the corrosion of metals in solutions (electrolytes) is electrolytic in nature and the rate of corrosion is dependent on many factors such as temperature, pressure, internal stresses, galvanic action, metal-ion concentration, and so on. In the chemical industry substances must be handled which are particularly corrosive to materials of construction. At the chemical plants of The Consolidated Mining and Smelting Co. of Canada, Ltd. (otherwise known as Cominco), situated at Trail, B. C., Canada, the following are some of the materials that have to be handled: Gases. Sulphur dioxide, sulphur trioxide, carbon dioxide, carbon monoxide, oxygen, hydrogen fluoride, ammonia, hydrogen sulphide, and oxides of nitrogen. Liquids. Solutions of ammonium sulphate, ammonium sulphite, ammonium nitrate, caustic soda and potash, sulphuric acid, nitric acid, hydrofluo-silicic acid, hydrofluoric acid, phosphoric acid, aqua ammonia, and formic acid. Solids. Gypsum (containing phosphoric acid), ammonium sulphate, ammonium nitrate, phosphate rock, caustic soda, potash, and phosphate fertilizers.

Jan 1, 1951

By E. A. G. Colls

IN all branches of the chemical industry, corrosion plays a very costly part unless it is suitably com-batted, and as a result it is probably correct that chemical and design engineers are more corrosion conscious in the field of chemical industry than in others. Most metals occur in nature in combination with other elements. The refined or reduced state to which man converts them for his use, by removing the combining elements, leaves them in an unstable condition. Therefore in most of the media to which the metals are exposed they are constantly combining with the constituents of their environment, or in other words they are continually being corroded. Similarly, nonmetallic materials are corroded by undergoing chemical change. The rate at which corrosion takes place varies widely from metal to metal and medium to medium. In practically all cases the corrosion of metals in solutions (electrolytes) is electrolytic in nature and the rate of corrosion is dependent on many factors such as temperature, pressure, internal stresses, galvanic action, metal-ion concentration, and so on. In the chemical industry substances must be handled which are particularly corrosive to materials of construction. At the chemical plants of The Consolidated Mining and Smelting Co. of Canada, Ltd. (otherwise known as Cominco), situated at Trail, B. C., Canada, the following are some of the materials that have to be handled: Gases. Sulphur dioxide, sulphur trioxide, carbon dioxide, carbon monoxide, oxygen, hydrogen fluoride, ammonia, hydrogen sulphide, and oxides of nitrogen. Liquids. Solutions of ammonium sulphate, ammonium sulphite, ammonium nitrate, caustic soda and potash, sulphuric acid, nitric acid, hydrofluo-silicic acid, hydrofluoric acid, phosphoric acid, aqua ammonia, and formic acid. Solids. Gypsum (containing phosphoric acid), ammonium sulphate, ammonium nitrate, phosphate rock, caustic soda, potash, and phosphate fertilizers.

Jan 1, 1951