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By B. N. Bose, M. F. Hawk

SINCE Davenport and Bain' introduced the isothermal transformation technique for the study of austenite decomposition in steels, a new field of investigation has opened up. Extensive research has been carried out on many different steels, but relatively little work has been done on eutectoid transformations in analogous alloy systems. The researches of Smith and Lindlief,² Mack,³ and Klier and Grymko²0 on the beta-phase transformation in copper-aluminum alloys, of Hibbard, Eichelrnan, and Saunders4 and Smith5 on the kappa-phase transformation in copper-silicon alloys, of Chaudron and Forester6 on the decomposition of "FeO," and of Wasserman7 on similarities between the iron-carbon, copper-aluminum, copper-tin, and copper-beryllium systems essentially comprise the field. The iron-nitrogen system, in view of its remarkable similarity to the iron-carbon system, is particularly attractive for the study of eutectoid decomposition. The present investigation is concerned with the study of isothermal transformation, proceeding by the familiar nucleation and growth processes, and of martensitic transformation characteristics of pure iron-nitrogen alloys. The kinetics of transformation and the morphology of the transformation products have been investigated, for these must be the factors determining the properties and behavior of the final product. The Iron-Nitrogen System he binary iron-nitrogen phase diagram has been a matter of considerable disagreement among vari01.1s investigators. However, the phase diagram according to Eisenhut and Kaupp8 and Lehrer10 is now considered essentially correct as reproduced in fig. 1. The important values, 2.35 pct nitrogen and 591°C, for the co-ordinates of the eutectoid point (obtained from this diagram and used in the re- search to be described) were confirmed in a concurrent study of Paranjpe, Cohen, Bever and Floe." The eutectoid decomposition involves the transformation of the ? face-centered cubic interstitial solid solution of nitrogen in iron to the a body-centered cubic interstitial solid solution of nitrogen in iron and the ?' nitride of iron. This nitride is essentially the compound Fe,N; it also possesses a face-centered cubic lattice but a considerably larger one than the ?; the nitrogen atoms in ?' are arranged in an ordered way in the centers of the unit cubes.8,10,11 A martensitic structure has also been reported8,12 in iron-nitrogen alloys and was studied in the research to be described here. Materials and Methods The specimens used in this investigation were prepared by nitriding "pure" iron. This iron was supplied by the Westinghouse Research Laboratories and is the product bearing their trade name "Puron"; it contains about 0.04 wt pct total impurities, the major portion of which is oxygen. Specimens were ribbons several inches long, a tenth of an inch wide, and 0.125 mm thick; this was the

Jan 1, 1951

By M. R. J. Wyllie

Eight laboratory-prepared aqueous base drilling muds representing common mud types, and 15 aqueous base drilling muds sampled in the field, have been used in an experimental investigation of the relationship between the streaming potential developed across a mud filter cake and the differential pressure causing filtrate flow. It has been established that the relationship is of the form, ES = kPy, where Es is the streaming potential, P the differential pressure and k and y are constants for any particular mud system at constant temperature. Beyond a certain minimum thickness this relationship is independent of filter cake thickness. Experiment has shown that both k and y are temperature dependent parameters and that in certain mud systems there is a critical value of P above which the simple relationship Es = kPY ceases to hold. The constant k tends to be a function of the mud resistivity at 77ºF, but the exponent y has not been found to be related to any commonly measured mud property. Certain field experiments are described which serve to demonstrate that the total SP (self potential) developed opposite a formation may be quantitatively accounted for as the algebraic sum of an electrochemical potential and an electrokinetic potential. A chart to permit the simple use of mean solution activities in the interpretation of electrochemical SP data is given and its use described. Various field methods for computing the electrokinetic SP component of the total SP are considered and rejected as being unduly complicated and inaccurate. It is shown that the employment of low resistivity drilling muds is essential if optimum accuracy is desired in the use of the S.P. curve for the purpose of computing connate water salinities by the electrochemical SP method. The use of such low resistivity drilling muds is accordingly recommended. INTRODUCTION In a previous paper' a quantitative analysis of the electrochemical compovent of the SP (self potential) curve was made and it was shown that the electrochemical* emf, E, could be expressed as E = ZtRT/F In a,/a,, where t is the transference number of the chloride ion, R is the gas constant, T the absolute temperature of the formation water and mud, a, the mean activity of the connate water (assumed to be sodium chloride) and a, the mean activity of the mud (as sodium chloride). The essential accuracy of this expression was confirmed by an investigation 2 of the SP kicks opposite sands of known water salinity. The logs examined had been routine runs in oil wells in a number of Mid-Continent states. Further confirmation of the original analysis of the electrochemical SP is implicit in the paper by Tixier3 wherein a relationship between the SP and the ratio of connate water and mud resistivities, based only on field data, is given. Allowing for the fact that mud and connate water resistivities were used instead of activities, and that electrokinetic effects were ignored, the constant reported by Tixier is essentially 2tRT/F. The error involved in the universal substitution of resistivities for activities will receive further reference below. Possible reasons for the fact that the electrochemical properties of shales do not appear to be significantly dependent upon either the nature or the quantity of cation exchange materials, such as clays, they contain has been considered at some length by Wyllie and Patnode.4 In the same paper, the probable effects of shale thickness and compaction on electrochemical efficiency, and hence the inherent difficulty of obtaining reliable laboratory-scale data, were also pointed out. However, it is

Jan 1, 1951

By E. W. Hough, B. B. Wood, M. J. Rzasa

An apparatus for the determination of fluid-fluid interfacial tension by the pendant drop method has been constructed. The apparatus is refined beyond those previously described in that the samples are introduced into an evacuated windowed cell without contacting air or mercury. Interfacial tension data are reported for the water-methane system between 74 and 280°F and 15 and 15,000 psi. The variation of wettability of the stainless-steel dropper tip with pressure and temperature was observed incidentally to the measurements. INTRODUCTION The most refined previous apparatus --for the determination of fluid-fluid interfacial tension at reservoir conditions was built by Hauser and Michaels.' These authors used the pendant drop method, previously investigated by Andreas, Hauser, and Tucker.' Recently, Fordham3 has made the pendant drop method an absolute one by numerical integration of the differential equation of drop shape. It is necessary to know the difference in density of the two fluids and the acceleration due to gravity in order to evaluate the interfacial tension from measurements of drop dimensions. Contact angle is not involved in the measurements by this method. Some precise tests of the method have been made at atmospheric pressure and 77°F by Douglas," who found agreement with established values to within about 0.1 per cent for water and air, cyclohexane and air, benzene and air, and benzene and water. No values of interfacial tension from the recent pendant drop apparatusJ have been published by Hauser and Michaels. However, values for the water-benzene and water-decane systems are given in Michaels' thesis5 or Dressures from 15 .to 10,000 psi and temperatures from 73 to 268ºF. Some determinations on gas-oil and gas-water systems in the range of 15 to 4,000 psi and 78 to 178°F have been made by Hozott,' by the drop-volume method. The capillary rise method has been used to investigate the interfacial tension in gas-oil systems at 88°F to several thousand psi by Swartz.7 Other determinations in gas-oil systems at pressures under 1,000 psia have been made by Jones: and Beecher and Parkhurst.9 The scarcity of data for pressures above 5.000 psi is apparent. APPARATUS An assembly drawing of the working section of the interfacial tenqion apparatus is given in Fig. 2. 'The endanant drop (A) is housed in a pressure chamber having glass windows (B). An agitator (6) is provided. The metal parts of the apparatus coming into contact with the sample are made of AISI: Type 316 steel. Drain grooves are provided around the whdows so that the sample in contact with the O-rings is not returned to the working section when the pressure is reduced. A schematic arrangement of the apparatus is given in Fig. 3. The working section containing the pendant drop (A) is filled by samples from bombs (B) with the aid of the vacuum system (C). The O-ring sealed pistons (D) used to separate the sample from the hydraulic fluid are shown together with the pressure production and measurement system (E). A front view of the apparatus is shown in Fig. 1. Most of the hydraulic system is at the top of the panel. The pump and displacement piston are at the lower right. The Variacs for the air bath heaters. the camera. and the vacuum gauge are a1so visible on the panel. The working section together with a window closure and a drop-forming tip closure are shown in Fig. 9. The carbon arc light source with filter is visible in the upper part of the picture. Two sides of the air bath with the impeller and a part of the convection shield can also be seen. The assembled air bath is shown in Fig. 10.

Jan 1, 1951

By R. A. Kinzie

THE major operating costs in a cement plant are labor, power, and fuel. The opportunities and methods of savings in labor and power parallel other industries. Because our industry's use of fuel is large and its method of use is unique, the devices adapted for saving fuel are of interest. In normal practice the raw material in the form of a dry powder or a mud is fed to a rotating inclined cylinder where it is dried, calcined, and clinkered. In a Lepol kiln the raw material is rolled up into little balls with water in the nodulizer, fed to a traveling grate on which it is dried and partially calcined and tben to a short kiln where the process is finished. The more usual methods of saving heat have been the use of long kilns with chains in wet process plants and the use of waste heat boilers in dry plants (fig. 1). At the Santa Cruz plant we have used a Lepol system kiln and achieved a fuel 'economy of 4.7 gal per bbl of clinker or about 704,-000 Btu per bbl. This can be compared with our old kilns using the same fuel and raw material which consume 7.8 gal per bbl or 1,130,000 Btu per bbl. These are gross Btu and not the net figures usually used in reports of foreign companies. Our average consumption for 1948 was 708,000 Btu per bbl of Lepol clinker, based on cement sold, and oil purchased. The overall fuel consumption for 1948 was 6.61 gal per bbl. The Lepol system consists of a nodulizer, a grate, and a kiln. There is the usual accessory equipment which is similar to that used in other cement plants. The following description covers the equipment in operation at our plant. The nodulizer is a cylinder 8 ft 10 in. in diam by 18 ft long set on a slope of 1/2 in. per ft, and rotated at about 10 rpm. It is driven by a 50 hp wound rotor motor drawing about 9 kw. The inside of the shell is cleaned by a continuously operating scraper which draws 0.1 kw. The dry raw material is fed to the nodulizer where, being sprayed with water, it rolls into small spheres about 90 pct being between 1/2 and 1 in. in diam and containing about 15 pct water. The nodules fall on the traveling grate where the hot gas from the kiln is pulled down through the

Jan 1, 1951

May I first of all say that I am fully conscious of the great compliment paid to me when I was invited to accept the Presidential Chair for this current year. I realise that it is an onerous task by reason of the fact that the Chair has been occupied in the past by so many able and distinguished men, and I realise also that I have been set a standard which is hard to emulate. "It is my desire however, in accepting the post that I may be able to contribute in some small measure to the further advancement Of the aims and objectives of the Institute and I thank you all for the confidence you have shown in me.Secondly, on behalf of the Company and in my Presidential capacity, I want to extend to each and everyone of you a hearty welcome to Whyalla and I hope that you will all return to your respective fields of endeavour feeling that you have had a most interesting, enjoyabIe and instructive time with us here in Whyalla.In this year of 1951 marking as it does the culmination of the first 50 years of Federation in Australia and yet another half century of human endeavour and progress, we are brought to a point where it is perhaps natural that we should pause, to review what has been achieved, in that span of time, and to look at the tasks ahead.It is no exaggeration to say that the story of Australian development since the inauguration of the Commonwealth 50 years ago has no more remarkable chapter than that of the-growth of its manufacturing industries.Each decade has borne witness to steady and substantial growth of our secondary industries and whilst it is true that our financial well-being still rests heavily on our primary production, we have, as a nation, moved surely in the direction of a more balanced economy. More and...

Jan 1, 1951

By Maurice Rey, Victor Formanek, Paul Chataignon

IT is found when floating oxidized lead ores by sulphidization, that the presence of calcium salts in the water, is usually detrimental and lowers the recovery. This effect is particularly marked in dry countries such as North Africa, where the waters often carry large amounts of calcium sulphate and where the ore may even contain gypsum. The effect of calcium salts is readily visible. Whereas in their absence cerussite is quickly stained brown and then black by sodium sulphide, in their presence the mineral remains very light in color. A similar effect is produced when barium sulphide is used as a sulphidizing agent instead of sodium sulphide. Magnesium salts have little or no effect and even tend to reduce the detrimental effect of calcium salts. A study of this phenomenon indicates that it is due to the precipitation of calcium or barium carbonate in contact with the mineral simultaneously with the formation of lead sulphide. The chemical reactions can be interpreted as: PbCO3 + Na2S = PbS + Na2CO3 CaSO4 + Na2CO3 = CaCO3 + Na2 SO4 They might also be written: PbCO3 + S = + Ca++ = PbS + CaCO3 The precipitation of calcium carbonate can be followed by the lowering of the pH with which it is accompanied. Magnesium carbonate is more soluble than calcium carbonate and usually does not precipitate under the conditions prevailing. It is interesting to note that calcium salts have no effect on anglesite (lead sulphate) because calcium sulphate is soluble, but barium salts hinder the sulphidization of anglesite because of the precipitation of barium sulphate. Remedies When calcium sulphate is present in large amounts, the softening of the water with soda ash is usually too expensive to be considered, but the precipitation of the objectionable calcium carbonate can be prevented in two different ways. One is the use of sodium hydrosulphide instead of sodium sulphide. This salt gives a lower pH than sodium sulphide and does not bring about the immediate precipitation of the calcium which remains in solution as calcium bicarbonate. The other procedure is to add ammonium salts such as the sulphate or chloride which have the property of increasing markedly the solubility of calcium carbonate. Ammonium salts have other effects such as cutting down conditioning time and accelerating flotation. They should be added to the flotation cells rather than to the ball mills. Table I. Effect of Sodium Hydrosulphide and/or Ammonium Sulphate on the Flotation of Two Oxidized Lead Ores Mibladen Ore4 La Plagne Ored Con- Tall- Con- Tail-centrate ing centrate ing Reagents Pb, Pct Pb, Pct Pb, Pct Pb, Pot Without addition of CaSO, NaS 56.0 0.68 43.4 0.65 NaSH 56.2 0.60 40.4 0.50 Na2S + (NH4)2SO4d 54.6 0.56 NaSH + (NH4)2SO4d 43.0 0.66 With addition of 40 lb/ton CaSO4 Na2S 39.4 3.85 34.0 3.21 NaSH 49.1 0.70 49.6 0.88 Na2S + (NH4)2SO4d 53.9 0.85 NaSH + (NH4)2SO4d 51.0 0.45 41.1 0.78 In table I are given the results of representative tests on two different oxidized ores. They show that the strongly detrimental effects of calcium sulphate can be offset by the two procedures outlined above. Sodium hydrosulphide is now used regularly on a mill scale on certain ores. Tests are being carried out with ammonium salts. It should be noted that malachite is subject to influences similar to cerussite. One final word of caution—when the ore is rich in primary slime, which is flocculated by the calcium salts, it may be indispensable to remove these by washing or precipitation with sodium carbonate instead of keeping them in solution by the above methods. Acknowledgment We wish to thank Socibtk Miniere & Metallurgique de Penarroya and Minerais et Metaux, for permission to publish these results.

Jan 1, 1951

By R. F. Mehl, C. E. Birchenall

SINCE Maxwell1 first considered the self-diffusion process in 1872 its importance in the kinetic theory of matter has been recognized. Until the discovery of isotopes in 1913, a direct measurement of this quantity seemed impossible. The only information that could be gathered indirectly was for gaseous systems for which the kinetic theory was well developed. When methods of direct observation be-came available, investigations on self-diffusion were carried out in condensed phases. In metals these data are presumably of potential importance in the study of recovery, recrystallization, creep, sintering, and related phenomena. Following the pioneer work of Von Hevesy2 and his collaborators, who determined the rate of self-diffusion in lead with the naturally occurring thorium B isotope, several metals have been investigated. Pb, Ag³, Au.6,5, and Cu6,7,8,9 are examples of isotropic crystals existing in only one phase modification. Anisotropy of diffusion has been demonstrated in Bil6 and Znll. This paper is a study of a single metal in two allotropic forms and also of self-diffusion in a body-centered cubic lattice. Despite the fact that the measurements in each of the papers cited on self-diffusion in copper seem to be internally consistent to about 10 to 15 pet, the curves reported by different authors differ by factors of 2 to 4 at the same temperatures. This uncertainty may account, in part, for the failure to establish a successful correlation between the self-diffusion rates and other physical characteristics of the metals. No satisfactory theory of metallic self- diffusion has as yet been proposed to account for all the existing data and to permit estimation in other metals. Experimental Part: Two units of radioactive iron were used in these experiments, each a mixture of Fe53 and Fe59 (12). Fe53 decays by K electron capture and the emission of an X ray with a half life of about 4 years. Fe59 emits two beta spectra, one with a maximum energy of 0.26 Mev, the other 0.46 Mev, and gamma rays of 1.1 and 1.3 Mev, with a half life of about 44 days. They were present in nearly equal concentration initially. The composite half life started at about 50 days and increased as the Fe59 decayed, leaving Fe55 relatively more abundant. After aging a year, the half life was too long to measure significant decay in a month. The absorption properties also changed with time. Because of the importance of the absorption coefficient in the diffusion calculations, it was necessary to determine this quantity frequently over the period during which these experiments were carried out. This correction was unsuspected at the time of publication of notesl3 on this work and accounts for the discrepancy in alpha iron and for part of the discrepancy in gamma iron.* * The data in the present paper supersede those given in the notes entirely. In one note the scale of log D was inadvertently reversed. In addition to the correction for the drift in absorption coefficient, the D values for gamma iron at low temperatures were high owing to insuficient correction for diffusion occurring during heating and cooling through the high temperature part of the alpha range at a rate much slower than that employed in the runs reported here. The high temperature alpha rates are much higher than the low temperature gamma rates and correspond to large equivalent times at these temperatures. These experiments were discarded and new measurements taken. Independent experiments with the same activity units indicated a radioactive contaminant in the iron, but exhaustive attempts to isolate and identify it chemically failed. These experiments? indicate † These experiments will be discussed in a later publication from this laboratory. that the contaminant represented only a trace of little importance in the diffusion results. The active iron was plated from an iron chloride solution. Enough of the solution was dropped on a 1% in. square of filter paper to wet it thoroughly.

Jan 1, 1951

By J. L. Taylor, P. Duwez

PARTIAL phase diagrams of titanium with iron, cobalt, and nickel have been established by previous investigators.1-3 These diagrams seem to be reliable, at least for concentrations of titanium ranging from 0 to about 50 at. pct. More recently, Long and his collaborators have presented a tentative titanium-nickel diagram covering the titanium-rich side.' These various studies indicate that in each system three intermediate phases exist and correspond to the compositions Tia, TiX, and TiX2 (or TiX3). The purpose of this paper is to review the available information on the crystal structure of these phases and to give the results of additional X-ray diffraction studies. Previous Work A summary of the work of Wallbaum and his collaborators"-' is presented in table I. The first intermediate phase on the titanium-rich side of the three systems, with iron, cobalt, and nickel, is of the Ti2X type and has a face-centered cubic structure. Although it is stated that the unit cell contains 96 atoms: no lattice parameters are given. The second phase is centered around the compositions TiX for the three systems. The crystal structure of this phase is mentioned in a short note" as being body-centered cubic (CsCl type), but no parameters are given. The analogy between the three systems, which is perfect as far as the two phases of the type Ti2X and TiX are concerned, disappears at the titanium-poor end of the diagrams. In the system titanium- iron, TiFe2 has an hexagonal (MgZn2 type) struc-ture with the parameters given in table I. The existence of TiFe3 has also been reported8 (table I) but was questioned by other investigators2 and is also refuted by the present study. In the system titanium-cobalt, a phase corre-sponding to the composition TiCo2 has been investi-gated by Wallbaum and Witte6 who claim that the structure is cubic (MgCu2 type) for alloys slightly deficient in cobalt and hexagonal (MgNi2 type) for alloys slightly deficient in titanium. The parameters of the two phases are given in table I. In the system titanium-nickel, the nickel-rich phase corresponds to the composition TiNi3 and has been described as hexagonal7 with the parameters given in table I. The present investigation was initiated for the purpose of filling in the gaps in the knowledge con-cerning the structure of the various phases sum-marized in table I. Since the titanium used by Wallbaum and his collaborators was only 95 pct pure,' it was found desirable to redetermine the lattice parameters of the alloys prepared with a

Jan 1, 1951

THE refining period of an open-hearth heat blends imperceptibly into the finishing period, during which final adjustments are made in slag composition, in bath action and temperature, and in composition of the steel, in order to prepare it for casting into ingots. Operations must be governed by the consideration that alterations in the character of the heat during the finishing period must be held to a minimum. In a broad sense, the finishing and deoxidation period of a heat may be said to begin when the action of the last ore addition has ceased, and to end when the teeming of the ingots is completed. INGOT STRUCTURES A survey of the relative advantages and disadvantages of different types of ingot structure is required because deoxidation treatments during the finishing period control the amount of gas evolved during solidification and consequently determine the type of ingot structure. Four classes of ingots are recognized, depending upon the degree of deoxidation to which the steel has been subjected. These types are killed, semikilled, capped, and rimmed; typical examples of their structures are represented by ingots 1, 2, 5, and 7, respectively, of Fig 9-1. The actual ingots from which these cross sections were sketched were all poured to the same height (indicated by the dotted lines) in the same type and size of bottle-top molds. The eight drawings of the figure represent selected types of ingot structure in a continuous series from "dead killed" to "wild," resulting from variations in the total quantity of gas evolved, from none at all to copious amounts, during solidification of the steel in the mold. Killed and semikilled steels are adjacent at the "quiescent" end of the ingot structure series where only small amounts of gas are evolved. The term "quiescent" describes the action of the molten metal during and subsequent to the teeming of killed and semikilled steels. Capped and rimmed steels are adjacent at the

Jan 1, 1951

By D. J. Salley, M. Burke, G. L. Simard

The depression of dithiophosphate by phosphate was investigated by correlating radiotagging measurements of competition in sorption with measurements of flotation. Competition in sorption was as complex as the sorption of the individual ions, thus strengthening the conclusion that more than one process was involved in the interaction of the ions with galena. The depression of flotation was chiefly a result of reducing the amount of dithiophosphate sorbed.

Jan 1, 1951

By T. B. Counselman

C. G. McLachlan—In the foregoing paper the author has presented a very neat method for calculating the solution recovery for a countercurrent flowsheet. He has, however, based his calculations, as he states, on the assumption that "the concentration of dissolved value must be exactly the same in the overflow and underflow of any thickener." This assumption, which is usually made regardless of the type of calculation used, is "not strictly correct because diffusion of the dissolved gold in the solution associated with the solids as it progresses through the countercurrent system is far from being instantaneous, with the result that on a ton for ton basis, the assay of the solution in the thickener underflow is higher than in the corresponding thickener overflow. An agitator introduced into the flowsheet between thickeners will reduce, but not entirely eliminate, this difference. In practice we have found that the best way to take care of this condition— in addition to the use of one or more intermediate agitators—is to circulate 20 pct or 25 pct more solution than called for by the cheoretical calculation. This presents no difficulty provided that adequate thickener capacity is provided in the original design of the countercurrent circuit.

Jan 1, 1951

By C. A. Siebert, D. J. Girardi

PRACTICALLY every metallurgical process in-volves, at some stage or another, the contact of a metal with a gas. Because of this, gas-metal re-actions are of great practical importance and have been subjected to numerous investigations. It has long been recognized that the presence of cuprous oxide in liquid copper has an important effect on its casting characteristics and .physical properties. This has led to the desirability of determining the quantitative relationships between cuprous oxide in the liquid copper and the usual gases present during processing. Such data are not only of practical importance but also of a theoretical interest in that they provide a means of applying the principles of physical chemistry to problems in applied metallurgy. The object of this investigation was to determine the quantitative relationship at equilibrium between the gases carbon monoxide and carbon dioxide and the cuprous oxide content of liquid copper. The reaction and its equilibrium constant may be expressed as follows: 2 Cu (liq) + CO2 (g) = Cu2O + CO (g) acu2o X aco/a2 cu X aco2 Here the underlined symbol Cu2O designates cuprous oxide dissolved in liquid copper and (a), the activity of the various constituents. The activities of carbon monoxide and carbon dioxide are assumed to be directly proportional to their re- spective partial pressures and the activities of cuprous oxide and copper are taken to be proportional to their respective mol fractions. The equilibrium constant may then be expressed as follows: K2 = Ncu2o X Pco [Ncu]2 X Pco2 where N = mol fraction The solubility of carbon monoxide and carbon dioxide in liquid copper is a rather controversial subject.'-' A review of the literature is given by 0. W. Ellis.' It appears that carbon monoxide and carbon dioxide are both only very slightly, if at all, soluble in liquid copper. Volskii and Slobodskoi5 determined the equilibrium between carbon monoxide, carbon dioxide, and liquid copper at 1100°C. Their results show a higher cuprous oxide content for a given CO/CO2 ratio than found in the present work. The system hydrogen, water vapor, and liquid copper was investigated by Allen and Hewitt8 over the temperature range of 1090" to 1350°C. Equilibrium values for the system carbon monoxide, carbon dioxide, and liquid copper calculated from these data agree reasonably well with the present work. Materials and Procedure The copper used was oxygen free, designated as OF and analyzed as 99.98 pct copper with no appreciable amount of any one impurity based upon spectrographic determinations. The carbon dioxide was cylinder gas averaging about 99.95 pct CO2 with air as the major impurity. The carbon monoxide was produced by passing carbon dioxide over heated charcoal. Alundum combustion boats were used as containers for the liquid copper. No appreciable reaction took place between the copper and the alumina. This was evident from the fact that the copper sample after a run did not ordinarily adhere to the bottom of the boat and that the

Jan 1, 1951

By L. Guttman, C. S. Barrett, J. S. Bowles

THE transformation from the face-centered cubic (Al) to the face-centered tetragonal (A6) structure in certain alloys of the indium-thallium system reported in the preceding paper1 exhibits many interesting crystallographic and metallo-graphic features, most of which presumably are similar to those of other cubic to tetragonal transformation such as, for example, the one which occurs in the chromium-manganese system,2 the one which, judging by microstructures and X-ray pat-terns,3 probably occurs in the copper-manganese system, the ones accompanying ordering in FePt,4 Copt,&apos; and AuCu,5 and the transformation near 115°C in barium titanate.6,7,8 If, as mentioned in ref. 1, the transformation is second order, the phases in equilibrium do not differ in composition, and it is both possible and likely that the mechanism is a diffusionless one. The present paper reports the results of a detailed study of the indium-thallium transformation and presents a theory for the atomic movements of the transformation which accounts for the observations. Experimental Crystallography of Transformation Markings The transformation from cubic to tetragonal in the indium-thallium alloys produces microstruc-tures of the type illustrated in fig. 1. These structures are observable either as relief effects produced on a smooth surface by the transformation, or after polishing and etching. These microstruc-tures are markedly similar to those found in copper-manganese alloys: iron-platinum alloys," and barium titanate,7,8 where it has been demonstrated that the lamellae are parallel to the (101) planes of the original cubic crystal. That the observed lamellae in indium-thallium alloys are also parallel to the (101) planes was proved by the following analyses performed on single grains in polycrystal-line samples containing 20.75 atomic pct T1. A study of the microstructures of a number of specimens revealed the fact that in many specimens the transformation markings continued unchanged in direction across the (111) interfaces of annealing twins. This at once demonstrates that the lamellae are parallel to a plane that is common to both parent and twin orientations, i.e., a plane in the zone <112>. This conclusion is compatible with the lamellae being parallel to (101) planes. To make a more complete determination of the habit plane of the lamellae, two grains were selected in which annealing twins ({Ill) twins) had been present in the high-temperature modification (cubic). The traces of the annealing twins, and of the transformation markings in both parent and twin crystals, were plotted together in stereographic projection, and a parent-twin pair of orientations was found that accounted for all lamellae as (101) planes. The projection of one of these twinned grains is reproduced in fig. 2. In view of these results the probability of there being another solution for the habit plane remote from (101) is very small, but to explore the possibility that the habit plane deviates slightly from (101), a more precise analysis was undertaken. In this, the orientation of a grain in the cubic modification was determined from a Laue back-reflection photograph taken with the sample at 90°C. The traces of the lamellae that formed in this grain on cooling were plotted in the stereographic projection

Jan 1, 1951

By Boyd Guthrie

As the American petroleum industry surveyed its position in early 1937, it had many reasons to be optimistic concerning its future. The industry had emerged successfully from the depression, and for the first time since 1929 it had produced over one billion barrels of crude oil in a single year. The demand for gasoline and fuel oils was up, and reserves of crude petroleum and production capacity seemed adequate for the future. Although production of crude oil dropped slightly in 1938, the oil industry was still in a good position with respect to its supply of raw material, which improved economically in 1939 with the decrease of crude-oil stocks in storage above ground. However, by 1940 a threatening cloud (the invasion of France and its rapid surrender) had appeared on the horizon. This aroused Somme fears as to the industry&apos;s immediate future, and these fears were intensified the following year when the United States entered World War II. As the war progressed, more and more ships, planes, and vehicles were produced, and the problem of obtaining enough liquid fuels to supply them intensified. Hearings were held in August 1943 before a subcommittee of the Committee on Public Lands and Surveys of the 78th Congress to determine the advisability of passing legislation to promote the development of synthetic liquid fuels.

Jan 1, 1951

By S. H. Ash

NO MORE important question has come before the coal-mining industry in many places, especially in the anthracite region of Pennsylvania, than prevention of stream pollution by mine drainage. Available information on acid mine drainage in the anthracite region of Pennsylvania indicates that a pollution problem must be solved in any program of anthracite mine drainage. The major problem concerns satisfactory disposal of the daily average mine-water discharge of 327,000 gallons per minute (g. p. m.), or 472 million gallons per day (g. p. d.), containing a free-acid load of 431 tons or a total acid load of 934 tons a clay as H2S04. This report indicates the scope of the problem and gives some suggestions concerning its solution.

Jan 1, 1951

By Walter E. Lewis

Ventilation-air-heating plants are in use at several iron mines on the Menominee Iron Range, Iron River, Mich. Many of the mines are exceptionally wet; during winter months, when fresh air is forced down the wet air shafts into the mine, it is usually necessary to heat the fresh air to above freezing so that the openings will not be closed by ice. The problem of ice closing air shafts has been solved by the practice of reversing the air current before the openings have become completely closed. This procedure involves drawing warm air from the mine up the usual down-draft air shaft. The M. A. Hanna Co. has found, at some of their mines on the Menominee Range, that it is more convenient to heat the below-freezing air rather than reverse the air current. Intermittent freezing and thawing of ice that has formed in the air shaft tends to loosen the wall rock, requiring major shaft repairs. The openings are kept free of ice the year around by heating the fresh air during periods of below-freezing weather. Table 1 shows the monthly minimum moan, maximum mean, and mean temperatures for the Iron River area. Under normal conditions of temperature, the furnaces are fired in November and usually are not allowed to go out until April of the following year.

Jan 1, 1951

By J. Chupak, D. J. Salley, G. L. Simard

DITHIOPHOSPHATES and xanthates are the principal collectors for sulphide minerals, and consequently any knowledge of mineral-collector systems of this type is of value. In the present investigation an attempt was made to obtain information on the interaction of a typical dithiophosphate with galena. In carrying out this study, radioiso-topes, so much discussed in the past few years,&apos;, &apos; were extensively employed. By using radioactive dithiophosphate synthesized from radioactive phosphorus, a rapid and sensitive analytical procedure G. L. SIMARD is in the Research Division, Stamford Research Labs., American Cyanamid Co., Stamford, Conn.; J. CHUPAK, formerly in the Research Division, Stamford Research Labs., is now at Camp Detrick, Frederick, Md.; and D. J. SALLEY is in the Research Division, Stamford Research Labs. AlME New York Meeting, Feb. 1950. TP 2815 B. Discussion (2 copies) may be sent to Transactions AlME before April 30, 1950. Manuscript received Oct. 17, 1949. was at hand. This permitted determination of such important quantities as the rate of uptake of dithiophosphate by the mineral, the amount existing at equilibrium on the mineral surface and in the solution, and the desorption of the agent from the surface. Such measurements were possible even on single crystals of galena. In addition the exchange of dithiophosphate between the solution and the sorbed phase was examined, a matter which could be accomplished only by the use of isotopes. It is desired to point out at this time that throughout this paper the term "sorption" has been employed to designate the uptake of agent by mineral, without implication as to the nature of the process by which the uptake was accomplished. Experimental Materials: Galena: The galena was from the Tri-State district. For studies on ground mineral four preparations were used during the course of the investigation. These were prepared from selected large crystals by wet grinding in order to reduce surface oxidation. Alcohol was chosen as a convenient medium for this purpose. The ground mineral was then fractionated by sedimentation in alcohol, dried by evacuation, and stored in a nitrogen-filled desiccator. Data on the preparations are tabulated in table I. The size analysis indicated that the areas of the preparations were of comparable magnitude, even though the absolute values may be somewhat incorrect. Dithiophosphates: Nonradioactive dithiophbsphate (di-isopropyl or di-secondary butyl) was obtained by purification of a commercial product. An aqueous acid solution of the agent was extracted with petroleum ether, the ether layer dried, and the dithiophosphate precipitated as ammonium salt with anhydrous ammonia. Several repetitions of this process resulted in a nearly colorless, flaky product of good purity. (General formula (RO,)PSSNH,). Radioactive dithiophosphate was synthesized by heating radioactive elementary red phosphorus* • For early experiments (1943 to 1944), the elementary red phosphorus was obtained from the cyclotron group at the Crocker Radiation Laboratory of the University of California. Berkeley, through the courtesy of Dr. Joseph W. Hamilton. For more recent work (1946 to 1949). the elementary radioactive Phosphorus has been supplied by the Oak Ridge National Labarotories on allocation from the U. S. Atomic Energy Commission. with sulphur at 270" to 300°C to produce radioactive P,S,. The latter was then treated with the desired purified alcohol (isopropyl or secondary butyl) at 60" to 80°C to form the dithiophosphoric acid derivative. Purification was effected in the same manner as for the nonradioactive material. The effectiveness of the purification method was established by the isotopic dilution method." The same technique was used to show that only negligible decomposition of neutral or of carbonate solutions of the dithiophosphate took place over a period of a day; this was true whether or not galena was suspended in the solutions. Procedures: Radioactivity: The activity of a solution was obtained by counting with a small glass-jacketed, silvered Geiger counter, using a conventional scaling circuit.&apos; Crystals and other solids were counted under a bell-shaped, mica-window counter tube. Sufficient counts were made so that the probable error of counting was of the order of +I-3 pct. The specific activity in terms of counts per minute

Jan 1, 1951

By J. C. Melrose, W. B. Lilienthal

The application of Bingham&apos;s law to the behavior of drilling fluids in a rotational viscometer permits the expression of viscometric data in terms of plastic viscosity and yield value, the flow properties of a plastic fluid. A commercially available rotational viscometer is described, and when modified to a multispeed type viscometer, is shown to provide a simple and convenient instrument for the measurement of these properties both in the laboratory and in the field. The data obtained are shown to be useful in defining and understanding mud control problems relating to chemical treatment and to the hydro-dynamic behavior of muds. INTRODUCTION The highly complex drilling fluids which are required for deep drilling often give rise to new and unusual mud control problems. Rapid and economic solutions to these problems may require, on the one hand, better understanding of the changes which contaminants and chemical treating agents produce in the colloidal and inert solids of the mud, or, on the other hand, closer control of the hydrodynamic behavior of the mud. The latter objective obviously can be achieved only if a correct rheological analysis of the flow behavior of drilling muds is available and if this is accompanied by the appropriate rheological measurements. The purpose of this paper is to describe such measurements in the field, and to show how the resulting data can be of value in solving difficult mud control problems. It is now generally recognized that Bingham&apos;s law of plastic flow can be utilized in describing the hydrodynamic behavior of drilling fluids in the non-turbulent flow range. Beck, Nuss, and Dunn&apos; have recently applied this law to the flow of mud in small pipes, and Rogers2 has reviewed the rather extensive literature on this subject. So far, however, the use of Bingham&apos;s law has been restricted to the analysis of mud flow in pipes or capillary tubes, and it has not been directly applied to the flow in rotational viscometers. In the work to be reprted, the Reiner-Riwlin3 equation for the flow of a plastic fluid in a rotational viscometer has been utilized to permit the expression of multispeed viscometric data in terms of plastic viscosity and yield value. the two absolute flow properties of a plastic fluid. With regard to the application of these measurements, the calculation of the relationship between pumping rate and pressure drop, both in the drill pipe and annular space, has long been a subject of interest. Beck, Nuss, and Dunn,&apos; following Caldwell and Babbitt: base their calculations for non-turbulent flow on Buckingham&apos;s integration of Bingham&apos;s law for pipe flow and measurements of the plastic viscosity (rigidity in their terminology) and yield value. In the case of turbulent flow, Fanning&apos;s equation is employed, and the pressure drop is relatively insensitive to the flow properties of the mud. Since flow in the drill pipe is likely to be turbulent at usual circulation rates, the plastic flow properties will chiefly influence the pressure drop in the annular space. As pointed out by Beck,&apos; the control of this component of the total pressure drop may be of special importance where lost circulation problems are encountered. Other hydrodynamic problems to which it should be possible to apply measurements of the plastic flow properties include predictions of the velocity distribution in non-turbulent flow and the critical velocity for transition to turbulence. Plastic viscosity and yield value. as abmlute flow propertie.;, will reflect the colloidal or surface-active behavior of the solids present in drilling fluids. Measurements of these properties should therefore find application in developing a better understanding of such behavior and in characterizing the type and condition of these solids. Garrison and ten Brink have utilized multispeed viscometric data in this manner. although their measurements were not expressed in terms of the absolute flow properties. In connection with the application of these measurements, it should be recognized that the presently used one-point viscosity measurements are relative in nature. The API Stormer 600-rpm measurement, for example. is a function of both plastic viscosity and yield value, as well as mud weight, and will often be misleading when its application to mud control problems is attempted. NOMENCLATURE, UNITS, AND DEFINITIONS In Fig. 1 an idealized plot is given of the flow variables involved in any viscometric measurement. It is seen that the flow behavior of plastic fluids is characterized by two constants — plastic viscosity, µp, and yield value, F. Other workers hate used the term rigidity for plastic viscosity or the term mobility for its reciprocal. The term plastic viscosity, however, emphasizes the close relation this property bears to the viscosity of a true fluid and is expressed in the familiar viscosity units of centipoises. The yield value is expressed in lbs/100 sq ft, the units adopted for gel strength measurements with the APT shearometer. Definitions of these properties based on rheological or macrc)scopic flow considerations follow from Fig. 1. The plastic viscosity of a substance obeying Bingham&apos;s equation is defined

Jan 1, 1951

Jan 1, 1951

By C. F. Floe, M. Cohen, M. B. Bever, V. G. Paranjpe

NITROGEN is becoming recognized as one of the important elements in ferrous physical metallurgy. Several investigations indicate that nitrogen plays a significant part in such phenomena as strain aging and temper brittleness. Nitrogen is known to be a powerful austenite stabilizer and may be a useful alloying element in stainless steels. The hard-enability of steels has been found to be increased by nitrogen. The nitriding and carbonitriding pro- cesses are examples of successful industrial application of nitrogen in ferrous materials. For a complete understanding of the various roles played by nitrogen in ferrous metallurgy a knowledge of the phase relations in the binary iron-nitrogen system is essential. The literature contains a variety of iron-nitrogen phase diagrams. Those suggested by Fry, Sawyer,² Epstein and his coworkers,³,4 Lehrer,5 Eisenhut and Kaupp, and Hägg7,8 differ significantly from one another. Moreover, the most recent of these investigations dates back about twenty years. A re-determination of the entire diagram, therefore, appeared desirable. In addition to the published phase diagrams, investigations have been carried out on portions of the iron-nitrogen system. Bramley and Haywood determined the composition and temperature of the iron-iron nitride eutectoid. The maximum solubility of nitrogen in a iron was investigated by Portevin and Seferian10 and by Diikstra. 11 Several investigators have determined the crystal structure of the various iron-nitrogen phases. In fact, Eisenhut and Kaupp6 and Hägg7 based their entire phase diagrams on the results of such studies. Epstein&apos; and Emmett12 reported lattice-parameter measurements on the E (hexagonal close-packed) phase. Osawa and Iwaisumi13 also studied the change in lattice parameters of the a, ? and E phases with nitrogen content. Brill" and Hägg7 showed that the y&apos; phase has an ordered structure, and Hendricks and Kostingsl5 suggested a structural relation between the E and phases. In a recent investigation Jackl6 arefully studied the super-lattice reflections from the y&apos; and phases. Experimental Procedure A large variety of experimental methods has been used by previous investigators in studying the iron-nitrogen system. These methods include thermal analysis, microscopic examination, X ray diffraction, magnetic measurements, dilatometric analysis and anelastic experiments. Thermal analysis is of low accuracy in determining changes in the solid state. This accuracy is further decreased for iron-nitrogen alloys since composition changes will occur during heating or cooling unless extreme care is taken to use a proper atmosphere. Metallographic methods are of small value . because homogeneous iron-nitrogen alloys of sufficient size can be produced only with great difficulty. The dilatometric method is open to the same objections as thermal analysis in that changes in composition may occur during heating and cooling. Lattice parameter measurements by X ray diffraction can be used satisfactorily for determining phase boundaries if cooling is fast enough to prevent structural changes. In view of the limitations of the various other techniques two methods only were adopted in this investigation, (1) X ray diffraction measurements, and (2) a controlled nitrogenizing method. The second method is an innovation for investigating the iron-nitrogen system, and will be described at length. Materials: All iron-nitrogen alloys were prepared from carbonyl iron powder of the analysis shown in table I. The average particle size was about 20

Jan 1, 1951