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By R. I. Jaffee, F. C. Holden, H. R. Ogden

The effects of grain size and shape on alloys of titanium with nitrogen and aluminum have been determined. Increasing a grain size decreases strength and hardness and increases impact resistance. Quenching from the ß field produces subgrain markings delineating a plates in Ti-N alloys but not in Ti-AI alloys. This suggests a precipitation from the high nitrogen alloys. ALPHA titanium alloys are single-phase alloys with the hexagonal-close-packed structure of a titanium. If these alloys are worked and annealed within the a field, equiaxed structures result in which strength is derived from the solid solution of the alloying elements present. Strain hardening can be used to increase further the strength of a titanium alloys. This is the only other mode of strengthening the a type of alloy. Quenching from the ß field has been noted by many investigators to have little effect on the strength of iodide titanium and on commercial titanium. Ti-A1 alloys were found to be little different in hardness, whether annealed in the a field or quenched from the ß field.' These facts illustrate a characteristic of a titanium alloys: they are insensitive to heat treatments from the ß field. Underlying this heat-treatment insensitivity are the facts that the a-ß field is generally narrow in a titanium alloys, the transformation-temperature range increases with a-stabilizing content, and the a solubilities of the alloying elements are greater than the ß solubilities. When quenching is done from the ß field, there is no supersaturation of the alloying elements in the acicular transformation structure produced. Welds in a titanium alloys generally are ductile, because no transformation hardening occurs during cooling.1,2 Other desirable features of a alloys are: no thermal-stability problem, excellent toughness, and retention of strength at elevated temperatures better than a-ß or ß alloys of comparable room-temperature strength. The prime factors governing the properties of a titanium alloys are the amount and kind of solute present. This can change the a phase from a soft, tough material into a hard, brittle material with no apparent change in microstructure. Moreover, brit-tleness can exist over a wider alloy-content range, without change of phase, than in most other metals. The solutes for a titanium may be divided into interstitial and substitutional types. Oxygen and nitrogen dissolve interstitially in rather large amounts, extending well through the brittle range, and the transformation-temverature ranges are raised in the process.:' , carbon has a maximum interstitial solubility of about 0.5 pct at the peritectoid temperature, while at lower temperatures the solubility decreases to about 0.2 pct.3,5 Substitutional a solutes include aluminum and tin. Aluminum has a high a solubility of 25 pct Al, and increases the transformation-temperature range markedly.6,7 Tin has a high a solubility of about 20 pct, but has a relatively innocuous effect on the transformation-temperature range.' The choice between interstitial and substitutional solutes generally has been conceded to the substitutional solutes because of a belief that they do not have as adverse an effect on ductility and notch toughness. However, a recent investigation8 on the effect of hydrogen on titanium has shown that this element, which is not under compositional control, has a powerful detrimental effect on notch toughness. Hydrogen was shown to form a hydride which is practically insoluble (about 0.002 pct) in a titanium at room temperature, although the solubility at the eutectoid temperature of about 300°C is relatively high, about 0.16 pct. Limited data were presented on the effect of hydrogen on a alloys, where the same impairment of toughness as in unalloyed titanium is found. The work reported here describes the effects of interstitial and substitutional solutes on 1—the mechanical properties of high purity titanium free of titanium hydride and 2—the influence of structural variables on these properties. Nitrogen was selected as an example of an interstitial solute with high solubility and aluminum as a substitutional solute with high solubility. All compositions were well within the ductile range, since it was not intended to study the brittleness problem here, but to study only the factors influencing optimum mechanical properties. Procedures The alloys were prepared from iodide titanium as 1/2 Ib ingots double melted to insure homogeneity.

Jan 1, 1955

By H. W. Ahrenholz

Seven weeks of 1971 were devoted to a nationwide coal walkout resulting in lost production of some 70 million tons and leaving 1971 coal production at about 550 million tons. Compounding the problem, consumption of coal in 1971 by electric utilities rose by about 5% to 336 million tons. In the mean- time, numerous contracts were awarded for coal R&D including $24.8 million given by the Office of Coal Research to Bituminous Coal Research for the construction of a coal-to-gas pilot plant using the BIGAS process. Exports declined mainly due to Japan's decrease in steel production and to that country's increase in coal imports from Canada and Australia. The advances in equipment design and mining procedures made 1971 a noteworthy year. Introduction of the variable pitch I dipper, the trend toward wheeled vehicles, the greater use of scrapers in reclamation and battery-operated vehicles and oscil-mining, and the increased activity in the areas of ventilation and dust control were given widespread approval. There were also strides made in computerization, longwall mining, roof bolting, rock dusting, mine haulage and methane detection.

Jan 2, 1972

By O. N. Carlson, H. A. Wilhelm, J. M. Dickinson

On the basis of microscopic studies, melting-point observations, and X-ray analyses, a phase diagram is proposed for the Cb-V system. A complete series of solid solutions is formed with a minimum in the solidus at 1810°C near 35 wt pct Cb. No compounds or intermediate phases were found in the system above 650°C. THERE is an ever increasing need for better structural metals and alloys for use in nuclear reactors. In addition to the normal properties of engineering structural materials, such as high temperature strength, resistance to corrosion, and fabric-abil~ty, the nuclear properties of the material must be considered. In a nuclear reactor it is important to conserve neutrons, so a material which removes these neutrons from the reaction excessively is considered to have unfavorable nuclear properties. In nuclear-reactor design the engineer must have nuclear as well as other data available on alloys in order to make a wise selection of materials. Due to the fact that many of the common structural materials have undesirable nuclear properties, it is vital that new alloys of metals having more favorable nuclear properties be investigated. Columbium and vanadium are both high melting metals, both exhibit resistance to chemical attack, and no great difficulty is encountered in fabricating them into desired shapes. With proper treatment both metals can be cold rolled extensively without failure. In addition they have desirable nuclear properties for certain types of reactors. Therefore, the alloys of columbium and vanadium should be of interest in the atomic energy program. Since an alloy-development program is enhanced by a knowledge of the phase equilibria of the components, this investigation was undertaken to establish the phase diagram for the Cb-V system. According to the Hume-Rothery rules for alloying,' the chemical similarity, crystal structure, and atomic-size factor are favorable for a complete series of solid solutions for this system. Both elements are in the same family of group V of the periodic table and thus are quite similar chemically. The crystal structures of columbium and vanadium are compatible for extensive solid solubility, since both have body-centered-cubic structures. The atomic diameters of columbium and vanadium are 2.85 and 2.62Å, respectively. This difference of slightly more than 8 pct is well within the 15 pct maximum difference allowed for extensive solid solubility. Experimental Procedures Source of Materials: Columbium powder and sheet trimmings were obtained from the Fansteel Metallurgical Corp. According to the manufacturer the metal contains less than 1 pct impurity. An analysis of the metal showed approximately 1800 ppm C in the powder while the sheet trimmings contained less than 500 ppm C. Spectrographic analysis showed minor amounts of Ca, Cr, Fe, Mn, Si, Ti, V, and Zr in both forms of the columbium. No commercial source of vanadium having the ductility and purity desired was available to the authors at the beginning of this investigation. As a result, all of the vanadium used in this study was prepared by the bomb reduction of vanadium pen-toxide with calcium employing the method reported by Long.' Yields of massive vanadium normally were about 80 pct. Chemical analysis of the vanadium prepared in this manner showed the presence of 200 to 500 ppm N and 800 to 1000 ppm C. Minor amounts of Ca, Fe, Mn, Si, Zr, Cr, and Cb were detected by spectrographic analysis. This vanadium metal was ductile and was cold rolled into 5 mil sheet. Annealing was not necessary during this rolling and the metal retained its cold-rolling characteristic after are-melting. Preparation of Alloys: The Cb-V alloys were prepared by melting pieces of vanadium sheet togethel-with columbium in the form of sheet or pellets of powder. The melting was carried out under argon in conventional arc-melting equipment employing a tungsten electrode and a water-cooled copper crucible. Each alloy was remelted three or four times, inverting the alloy after each melting in order to assure complete mixing. Alloys normally were obtained as round flat disks, weighed approximately 70 grams, and had roughly the shape of a disk 1 1/2 in. in diameter and 1/4 in. thick. Half of each alloy

Jan 1, 1955

Members Dues Resignations, Suspensions and Expulsions Institute Meetings Board of Director?s Meetings Directors and Officers Duties of Officers Committees Nomination and Election of Officers Publications Divisions, Local Sections, Affiliated Societies Amendments [As REVISED FEBRUARY 21, 19281 ARTICLE I MEMBERS-QUALIFICATIONS AND ELECTION , SEC. 1. The membership of the Institute shall comprise six classes, namely: 1. Members; 2. Honorary Members; 3. Senior Members; 4. Associates; 5. Junior Associates; 6. Rocky Mountain Members. All shall be equally entitled to the privileges of membership, excepting that Junior Associates, and all Members and Associates whose residence shall be outside of the United States of America, Mexico and Canada shall not be entitled to vote. SEC. 2. Members: A person to be eligible for election or transfer into the class of Member must be at least 27 years of age and must have had at least six years' employment in the practice of engineering, mining, geology, metallurgy, or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. This shall not apply to Rocky Mountain members.

Jan 1, 1928

By Arthur F. Taggart

The following conclusions on the work of the Hardinge mill are based on data furnished to the writer by the Hardinge Conical Mill Co. in the form of the mesh cards hereto appended. Energy units (E. U.) and relative mechanical efficiencies (R. M. E.) are computed by the "volume method" of Stadler.' Screen apertures used are the average apertures of testing screeps of the meshes given. i . Card 122. June 28, 1912. Vipond Porcupine Mines Co., Ltd., Schumacher, Ont., Canada. Ore from mill bin. Gangue, quartz and basalt. 4.5 ft. by 13 in. ball mill, Capacity, 48 tons per 24 hr. Charge, 4,000 lb. balls. Speed, 33 rev. per minute. Horsepower, 15 to 17. Water, 100 per cent. by weight. (50 per cent. ?) Product deslimed and oversise reground in pebble mill, see Card 113. Feed to mill through 2-in. mesh. Mesh Feed, Per Cent. Discharge, Per Cent.. + 1in. 5.50 ....... + 3/4. 28.00 + in. 30.00 ...... + 1/4in. 19.72 ....... + 10 10.87 2.10 + 20 2.42 8.00 -20 3.51 .....,. + 40 ....... 22.68 + 60 ...___ 10.50 4-80 ....... 11.80 + 100 ....... 3.90 -100 ....... 40.15

Jan 1, 1916

By V. F. Hollister

The South American porphyry copper province includes most of the Andean orogen, excepting the tin province of Bolivia. Porphyry coppers have not been commonly found within the tin belt, though copper-tin deposits in San Rafael, Peru and copper-tungsten deposits in Llamuco, Chile, are known. James" shows the depth to the Moho to appreciably thicken where the tin belt exists, but disclaims any genetic significance from this coincidence. Table I gives some of the most important porphyry copper deposits explored to date, but does not include Antaminas, Peru, nor a number of other large skarn deposits associated with intrusions. V. D. Perry* points out that porphyry copper mineralization does occur to some extent in the intrusion associated with many of these skarn deposits. Also not included are the suspected possible porphyry type occurrences, such as, for example, quartz-sericitically altered lower levels of the Casapalca mine, Peru. Many deposits not well enough documented to list in a summary paper are also excluded. Should anyone care to tabulate all other large copper de- posits in South America, they could demonstrate that a tremendous potential awaits the proper political and economic climate in the future.

Jan 8, 1973

By F. Lynwood Garrison

As the specific gravity of low-carbon steel seems to be attracting considerable attention as a means of détermining the quality and value of the metal, I give here a few of the results of a long series of experiments recently made by me. The object of the experiments not requiring more than approximate correctness in the third place of decimals, the extreme precautions to obtain accuracy which are sometimes used in determining specific gravity were not observed. But each piece of metal was carefully cleaned to remove scale, rust, dirt, etc., thoroughly dried, and then weighed in air, all weighings being carefully repeated. The balance used was one of Troemner's finest, and sensitive to one-tenth of a milligram. Before weighing in distilled water, care was taken to remove, as far as possible, the air enclosed in the pores of the metal. The pieces of metal were suspended by means of fine silk thread, a correction of course being made for the weight of the silk. Care was taken that the water in which they were weighed should he always at the same level, and, as far as possible, at the same temperature.

Jan 1, 1887

By Alan U. Seybolt

In examination of some cold-rolled copper and cupronickel that contained a little columbium, it was discovered that these alloys were unusually resistant to annealing. This effect was suficiently pronounced to warrant some investigation of the annealing characteristics of such compositions. Experimental Procedure The alloys were made from cathode copper, electrolytic nickel, and a special copper-columbium hardener alloy furnished by the Electro Metallurgical Corporation. This hardener alloy contained 10 per cent columbium, with tantalum, aluminum and iron as major impurities. The melting was carried out in a clay-graphite crucible in a high-frequency induction furnace! under a charcoal or electrode carbon cover. No deoxidizing additions were made. The 7-lb. copper heats were poured into a steel mold, hot-rolled to 1/4-in. thickness, and annealed for 56 hr. at 760°C.; the cupronickels were annealed I hr. at 815°C. The material was then cold-rolled to a 50 per cent reduction in thickness and annealing tests were carried out on this 1/8-in. hard-rolled strip. A little silver was added to copper-columbium alloys 402 and 403 to find out

Jan 1, 1942

By Alan U. Seybolt

In examination of some cold-rolled copper and cupronickel that contained a little columbium, it was discovered that these alloys were unusually resistant to annealing. This effect was suficiently pronounced to warrant some investigation of the annealing characteristics of such compositions. Experimental Procedure The alloys were made from cathode copper, electrolytic nickel, and a special copper-columbium hardener alloy furnished by the Electro Metallurgical Corporation. This hardener alloy contained 10 per cent columbium, with tantalum, aluminum and iron as major impurities. The melting was carried out in a clay-graphite crucible in a high-frequency induction furnace! under a charcoal or electrode carbon cover. No deoxidizing additions were made. The 7-lb. copper heats were poured into a steel mold, hot-rolled to 1/4-in. thickness, and annealed for 56 hr. at 760°C.; the cupronickels were annealed I hr. at 815°C. The material was then cold-rolled to a 50 per cent reduction in thickness and annealing tests were carried out on this 1/8-in. hard-rolled strip. A little silver was added to copper-columbium alloys 402 and 403 to find out

Jan 1, 1942

Why should I pay $8.50 an hour for dealer repairs when my own mechanics work for $3.50?" The numbers vary, but that's the argument most contractors use to justify doing their own repairs. They don't realize it, but they're probably losing big money. For instance, it takes nearly a quarter of a million dollars in tools alone to equip a shop comparable to an average equipment dealer's facilities. A contractor must buy a lot of expensive, specialized tools he seldom uses, or else settle for the inefficiency of having repairs done by his mechanics with relatively unsophisticated tools. His building soaks up money in rent, maintenance insurance, taxes. His mechanics demand good wages. It even costs money when mechanics aren't repairing equipment. Mechanics get full wages for slack periods and cleanup time, too. This doesn't count as service manhours, but it's still part of the total repair cost. To help contractors uncover these hidden expenses and find out the true cost of owning a shop, some equipment dealers have devised a do-it-yourself "shop cost analysis form."

Jan 1, 1970

By Fred P. Dewey

The iron ores of Canada have attracted more or less attention in this country for a number of years ; and having had an opportunity this past summer to examine some of them, especially the magnetic ores, I have thought it might be of sufficient interest to the members of the Institute to put on record some of my observations. The region examined contains, for the most part, only the rocks of the Laurentian system. Much of it was originally covered with a dense growth of pine, which interfered with successful prospecting for ores. However, after the best of the timber had been cut off, fire generally got into the bush and cleared it up pretty well. This, besides making travelling about easier, exposed large surfaces of rock, and rendered the work of the prospector far more liable to be rewarded with success, while removing many of its hardships. The general appearance and productiveness of the land have, however, been far from improved by this process. It would be difficult to find a more desolate-appearing country than some of these pine woods after fire has been through them. The country examined may be, for convenience, divided into two

Jan 1, 1884

By John Nelson

AN OUTLINE survey of the economic outlook for the United States export trade in petroleum products resolves itself broadly into two general divisions; first, a consideration of our present position in this trade, and second, a discussion of the visible factors which promise to affect appreciable changes in the immediate future in that trade. The UNITED STATES PETROLEUM EXPORTS OF MAJOR PETROLEUM PRODUCTS 1925, 1926 and 1927 Gasoline, Naphtha, and Other Light Products 1925 1926 1927* Quantity (gal.) 1,286,787,796 1,784,154,802 1,851,494,190 Value $197,491,588 $263,199,938 $214,721,652 'Illuminating Oil, Kerosene 1925 1926 1927* Quantity (gal.) 885;136,041 924,680,979 827,162,280 Value $84,699,724 $100,352,877 $80,358,082 Gas and Fuel Oil 1925 1926 I 1927 Quantity (gal.) 1,365,358,988 1,449,688,394 1,815,130,464 Value.... ? $49,040,024 $45,354,108. .. $50,343,031 Lubricating. Oil 1925... ....1926 .. 1927 Quantity .(gal.) 402,572,584 388,767,055 403,369,512 Value $90,596,671 $86,414,621 $88,926,815

Jan 1, 1928

By W. M. Morris

THE volumetric behavior of isobutane at temperatures below its critical temperature has been studied by several investigators. Seibert and Burrell1 measured the vapor pressure of isobutane from the ice point to the critical temperature. Dana and co-workers2 determined among other thermodynamic quantities the density of the saturated liquid and the saturated gas and the vapor pressure from approximately 0° to 130° F. Sage and Lacey3 studied a number of the thermodynamic properties of this hydrocarbon from 70° to 250° F. The specific volume in the gas and liquid region was determined at pressures up to 3000 lb. per sq. in. ? throughout this temperature interval. In addition, the vapor pressures were measured at 30° intervals. These data taken together serve to establish the thermodynamic behavior of isobutane at temperatures between 0° and 250° F. with reasonable accuracy. However, apparently there are no data available at the higher temperatures. For this reason an investigation of the volumetric behavior of isobutane at temperatures between 100° and 460° F. was carried out with apparatus that has been described in another paper (A.I.M.E. Tech. Pub. 1127).

Jan 1, 1939

By P. G. Winchell, R. J. Russell

The distribution of displacements of originally plane surfaces by an invariant-plane strain has been analyzed statistically. The displacement ratio (the magnitude of the displacement of a point originally a unit distance from the invariant plane) can be determined from an analysis either of tilts of random surfaces or of displacements of random scratches scribed on a randowz surface. In either case the mean of the tangent of the observed displacement angle is related to the displacement ratio, and the number of observations used in determining the mean is related to the confidence limits placed on the estimate of the displacement ratio. In estimating the effect of applied stress on a phase transformation whose displacement effects can be approximated as an invariant-plane strain,* the dis- placement ratio of the invariant-plane strain is of primary importance. Two procedures for determining such displacement ratios are considered here. In the tilt method the measured quantity is taken to be the angle through which a random polish plane is rotated by the invariant-plane strain. In the scratch method the measured quantity is taken to be the angle between the original direction of a random scratch in a random polish plane and the projection of its final direction in the polish plane. In order to obtain precise results from either of the methods, it is necessary to measure the relative volume change associated with the strain in a separate experiment. TILT METHOD A locally homogeneous invariant-plane strain, P, with displacement ratio, S, may be written&apos; where ; and < are unit vectors indicating the displacement direction and invariant-plane normal, respectively, as pictured in Fig. 1. Eq. [I] describes a uniaxial strain if the direction of displacement is parallel to the invariant-plane normal and a pure shear strain if the displacement direction is perpendicular to the invariant-plane normal. The original orientation of the random polish plane relative to the invariant plane and to the displacement direction is shown in Fig. 2. The angle 03 between < and u is related to the relative volume change, ?V/V, and to the displacement ratio by As a result of the invariant-plane strain, the polish plane is rotated about its intersection with the invariant plane by the angle y, which is always taken to be positive. The tangent of this angle in terms of the above parameters is

Jan 1, 1967

By J. W. Galpin, R. H. Allen

Controlled pre-grouting is a technique developed during a period of more than ten Years experience, in an effort to produce safer, drier and more economical mine shaft sinking. The technique involves a knowledge Of hydro-mechanics, both static and dynamic, and a series of specially formulated grout mixtures to obtain several desired results through precontrolled setting time. In general, the following procedures have been used to secure the best results in controlled pre-grouting: I. Before drilling is commenced, One Of two decisions is made: one procedure, a modified form of the Francois method, is to stage drill and grout, that is, drill a limited portion of the hole, then grout and redrill that section which has been grouted, progressing in stages until the required depth is reached. We prefer this method because no casing Or grouting packers are required in the bore hole. This eliminates the risk of losing them in the bore hole due to packer failure, which might result in the expense of drilling a new grout hole. Another feature Of this approach is that smaller drill holes may be effectively used, further reducing the costs. One drawback, however, is that because of the open and small size hole, it is impractical to attempt water draw-down tests. The second alternative is to drill the bore hole, (generally NX size), to the re-quire~ depth. he casing and grouting packer are placed in the bore hole at the lowest packer setting. A small, portable, power driven, swabbing device is used in the grouting casing to test the packer and remove mud or cuttings from the bore hole below the packer. The hydrostatic level is recorded and a close estimate or test is made of the quantity of water at each packer setting. Grouting progresses upward in a series of packer settings to the surface. Occasionally, casing is inserted in the bot-tom of the bore hole from within the mine, and water pressure and volume can be obtained in this manner. This is usually dangerous because of the unknown quantity of water. 2. The grouting, mining and geological engineers at the drill location make a detailed examination of the cores and also locate proper and firm grouting packer locations. A competent driller,s opinion should be given due consideration as to the character and condition of the bore hole. 3. Several samples of formation water

Jan 1, 1949

By G. R. St. Pierre, S. W. Gilby

The equilibrium vapors established over Fe-Cr-Ni alloys containing up to 50 pct Cr at 1600°C were determined by collecting the effusate from thoria Knud-sen cells. From these data, the activities of iron and nickel in the ternary alloys have been calculated. In a separate set of measurements, a mass spectrometer was used to determine the activities of the three components in a series of Fe-Cr-Ni alloys. In binary Ni-Cr melts, the activity coefficient of chromium referred to pure solid chromium as standard state is less than one at low chromium contents but is greater than one for melts containing more than 30 at. pct Cr. For Ni-Cr melts containing less than 10 at. pct Cr, In ?Cr = 0.15-0.92 N2. Ternary activity diagrams for Fe-Cr-Ni alloys are presented. In iron-rich alloys, the interactions between the three components are negligible; however, in nickel-rich alloys, the three principal interactions have significant positive values. THE activities of components in binary Fe-Ni alloys have been measured both in the solid solution1-3 and liquid solution4-6 temperature ranges. The determination for Fe-Ni melts have been made by three different methods: transpiration,4 Knudsen-cell effusion with analysis of an accumulated condensate,&apos; and Knudsen-cell effusion with direct measurements of relative component intensities by mass spectrometric methods.6 The results obtained by the three different methods in three different laboratories are in excellent agreement and considerable confidence is placed in the activity coefficients for Fe-Ni melts. At 1600°C, the activity coefficients in dilute solution are ?°Ni = 0.66 and ?oFe = 0.40 for the pure liquid components as standard states. Measurements made on solid solution Fe-Cr alloys7-10 indicate that the component activities are slightly greater than ideal. The measured activities in iron-rich Fe-Cr liquid alloy11-16 indicate almost ideal behavior for this system. The recommended activity coefficient of chromium in dilute solution in liquid iron at 1600o C, ?oCr, is 1.18 when referred to pure solid chromium as standard state and 1.04 when referred to pure undercooled liquid chromium as standard state." The conversion factor of 1.14 is based on a melting point of 1857°C and an enthalpy of melting of 4047 cal per g at. for chromium.21,37 The activity coefficient of iron in dilute solution in liquid chromium has not been measured. Activity measurements on solid Ni-Cr alloys have been made by several investigators.17-20 During the review of this manuscript, Fruehan12 published the results of a study on liquid Ni-Cr alloys at 1600°C. He used galvanic cells22 with ZrO2(CaO) as the electrolyte and Cr/Cr2O3 for the reference electrode. His results indicate that ?oCr in nickel at 1600°C is about 1.01 when referred to pure solid chromium and about 0.89 when referred to pure undercooled liquid chromium as standard state. The activity coefficient of nickel in liquid chromium is unknown. The compositions of vapors freely evaporating from some molten Fe-Cr-Ni alloys have been measured by Lyubimov, Granovskaya, and Berenstein.23 Their results, combined with known vapor pressures, indicate strong positive deviation for chromium in iron-rich alloys and strong negative deviation for chromium in nickel-rich alloys. EXPERIMENTAL PROCEDURES This research was undertaken to determine the activities of components in ternary Fe-Cr-Ni melts containing up to 50 at. pct Cr. At the initiation of the research, we decided to use a Knudsen-cell method wherein a portion of the effusing vapor is condensed on a cold plate.&apos; The composition of the equilibrium vapor for each alloy composition is determined in this method by holding the system under constant conditions for a period of time sufficient to collect enough condensate on the cold plate for chemical analysis. The activities of components in ternary alloys can be calculated from such vapor composition determinations by Eq. [1].24

Jan 1, 1970

By J. L. Rodda, R. L. Wilcox, E. C. Truesdale

IN recent years various problems in connection with research work on the preparation and properties of zinc-base alloys have required reliable information concerning the constitution of the zinc-rich portion of the iron-zinc equilibrium diagram. On numerous occasions rather positive indications were obtained that, for example, the solubility of iron in zinc was incorrectly represented on .the current equilibrium diagrams.. A careful study of all the available literature relating to the iron-zinc system led to the conclusion that much of the early work was unsatisfactory as measured by present standards of experimental accuracy, and as a result it was decided to redetermine the location of the liquidus curve and of adjacent portions of the diagram. Part I. of this paper comprises a description of the experimental methods and a summary of the results by means of which the zinc-rich end of the iron-zinc diagram has been revised in the following ways: 1. Measurements of the solubility of iron in liquid zinc by several different sampling methods, leading to a relocation of the liquidus curve. 2. Microscopic, conductivity, and X-ray studies of the solid solubility of iron in zinc, which, together with thermal analyses, have resulted in new values for the solid solubility and the eutectic temperature and composition. 3. Heating and cooling curves, obtained by a refined differential method, leading to new locations for the two peritectic horizontals. In Part II of the paper the attempt is made to review all of the published work having a bearing on the constitution of the iron-zinc system, and to correlate the present results, and some recently published data

Jan 1, 1935

By R. B. Burt, James A. Barr, I. S. Tillotson

THE pumping of solids in water suspension is an important part of many metallurgical and mining operations. In most cases, it is still in the rule of thumb category for which no universal formula has been developed, and much research is needed. Because of the limited and incomplete data available, this article may be classed as an experience paper, which is presented with the hope that some contribution will be made toward the development of the so-called universal formula. This formula, if and when developed, may be evolved from several factors, many of which are not now available for general application. The designing engineer is interested in obtaining accurate forecasts on: 1-the minimum velocities needed to prevent choke-ups in the pipeline, which in turn dictates pipe sizes, 2-power required for pumping, 3-pump selection. The basic factors for a given problem will include: 1-weight per unit of time of solids to be handled, 2-specific gravity of solids, for calculation of volume, friction and power, 3-screen analysis of solids with the colloidal acting, i.e., the slime fraction, a very important factor, 4-shape of particle or some means of determining a friction constant, 5-effects of percentage of solids, 6-development of a viscosity factor to be used in the overall calculations, 7-calculation of the lower limits of pipeline velocities permissible, 8-calculation of total head, pump horsepower, and 9-setting up of pump specifications. In certain limited cases horsepower and total heads and minimum velocities may be computed and a suitable pump selected from basic data, but in many cases, as in mining of Florida pebble, phosphate, experience rather than a hydraulic formula still should be used as a basis of selection. Pumping Florida Pebble Matrix Pumping at the Noralyn mine of International Minerals and Chemical Corp. will be used as an example. Other areas will vary as to the characteristics of the matrix, especially the slime content. A typical screen analysis of this matrix is: +14 mesh, pebble size,* 2.1 pct; -14 +35 mesh, 11.4 pct; -35 +150 mesh, 60.5 pct; -150 mesh, 25.0; total, 100 pct; moisture in bank, 20.0 pct; weight per cu ft in bank, 120 lb. The -150 mesh fraction may increase to as much as 35 pct in adjacent areas. When thoroughly elutriated, the matrix has a relatively slow settling rate, which is an important factor in permitting lower pipeline velocities without choke-ups. Exact data is not available to evaluate settling rates. For a factor of 100 a suspension of clean building sand in water is suggested. When pumping long distances, a quick settling matrix allows the coarser solids to settle out along the bottom of the pipeline, causing drag, turbulence, and increased friction. With a slow settling matrix as at Noralyn, turbulence acts to keep the solids in suspension at a lower friction head, regardless of the pumping distance. When the pebble, content of the matrix, i.e., the +14 mesh fraction, is in excess of 10 pct of the total solids, trouble may be expected from settling out even in normal pumping distances. To prevent choke-ups and maintain tonnage, an additional pump must be added in the long runs, where one pump would otherwise be satisfactory. A typical pulp handled is: total volume, 7800 gpm; water, 4500; solids pumped per hr, 4200 lb; sp gr pulp, 1.4; percent solids in pulp, 46.; pipe size, 16-in. ID; pulp velocity, 12.85 fps; probable critical velocity, 10 fps, as below this minimum -velocity choke-ups would be numerous. In calculating friction heads the Armco handbook is used where a roughness factor based on 15-year-old pipe is set up. Because the pipe used in pumping matrix is, smooth and- polished because of the scouring, action of the phosphate and its silica content, the head losses in the Armco table for water are practically the same as in pumping the Noralyn matrix through smooth pipe, plus the fact that conditions vary widely over short periods, making accurate determinations difficult to obtain. New pumps and pump, changes are being tested continuously and a wealth of data built up. This has resulted in a substantial improvement and lower relative costs in pumping matrix. The Florida phosphate industry is constantly seeking to offset higher wage and material costs with improved technique. Until a few years ago a 12-in. discharge pump was commonly used, with heads as low as 80 ft. Sizes have gradually increased and heads more than doubled. For example, the following pump was placed under test at the Noralyn mine: make, Georgia Iron Works; size, suction 16 in., discharge 14 in.; impeller, 39-in. diam; motor, 600 hp, slip ring; full load speed, 514 rpm. The results were increased head, higher capacity than the older design, with fewer pumps in the line from mine to washer.

Jan 1, 1952

By E. C. Truesdale

IN recent years various problems in connection with research work on the preparation and properties of zinc-base alloys have required reliable information concerning the constitution of the zinc-rich portion of the iron-zinc equilibrium diagram. On numerous occasions rather positive indications were obtained that, for example, the solubility of iron in zinc was incorrectly represented on the current equilibrium diagrams. A careful study of all the available literature relating to the iron-zinc system led to the conclusion that much of the early work was unsatisfactory as measured by present standards of experimental accuracy, and as a result it was decided to redetermine the location of the liquidus curve and of adjacent portions of the diagram. Part I of this paper comprises a description of the experimental methods and a summary of the results by means of which the zinc-rich end of the iron-zinc diagram has been revised in the following ways: 1. Measurements of the solubility of iron in liquid zinc by several different sampling methods, leading to a relocation of the liquidus curve. 2. Microscopic, conductivity, and X-ray studies of the solid solubility of iron in zinc, which, together with thermal analyses, have resulted in new values for the solid solubility and the eutectic temperature and composition. 3. Heating and cooling curves, obtained by a refined differential method, leading to new locations for the two peritectic horizontals. In Part II of the paper the attempt is made to review all of the pub-lished work having a bearing on the constitution of the iron-zinc system, and to correlate the present results, and some recently published data

Jan 1, 1935

By C.F. Pascoe, H.J. Roast

The object of this investigation was to compare the arsenical antimony-lead alloy with some of the regular bearing-metal alloys. With this end in view, the following tests were made: 1. Chemical analyses to show the composition. 2. Thermal analyses. 3. Macroscopic examination of fractures. 4.Microscopic examination. 5. Tensile tests. 6. Crushing tests. 7. Scleroscope tests.&apos; 8. Brinell tests, at temperatures from 80&apos; to 400&apos; F. Tests 3 to 8 were conducted on both sand-cast and chill-cast specimens. For the purposes of this paper the alloys have been numbered from 1 to 6; their composition is as follows: Lead. &apos; Antimony, Tin, CoppeR ARSEnic, NumBeR PeR CENT. PER CENT. PeR Cent. PeR CeNt. PeR Cent. 1 82.64 12.95 4.40 0.01 none 2 27.54 9.04 59.87 2.65 none I 3 none- 0.13 ------------1.47 4 82.95 16.85 none 0.20 none 5 83.78 15.35 none 0.05 0.82 6 0.15 7.87 . 84.13 7.85 none The analysis, in the case of the antimony, was made by solution in sul-furic acid and titrated with permanganate. For tin, the ferric-chloride method was used; for copper, the alkaline separations, and the thio-cyanate methods; for arsenic, volatilization of arsenic and titration with iodine. The lead, with the exception of alloy 6, was taken by difference. With the exception of No. 5, the alloys were taken as received from the manufacturer. About 40 lb, were melted in a graphite crucible and recast into small ingots to insure uniformity of composition; samples

Jan 1, 1923