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By W. N. Lacey, B. H. Sage

The growing background of experimental information concerning the volumetric and phase behavior of binary and ternary hydrocarbon systems is used as the basis for a comparison of these systems with naturally occurring hydrocarbon mixtures under conditions representative of underground petroleum reservoirs. The qualitative and semiquantitative similarities and differences between the two types of systems are considered in reference to the possibilities and limitations of using experimental data on binary and ternary systems for predicting the volumetric and phase behavior of naturally occurring hydrocarbon mixtures of low molecular weight. The possible influence on such phase behavior of water, hydrogen sulphide, nitrogen, and components of relatively high molecular weight is discussed. INTRODUCTION During the past two decades much effort has been devoted to the study of the volumetric and phase behavior of pure paraffin hydrocarbons and of binary and ternary mixtures of these compounds. Many of these studies were carried out with the direct objective of utilizing a knowledge of the detailed characteristics of binary and ternary mixtures of the lighter paraffin hydrocarbons for predicting the behavior of more complex mixtures. The ability to make such predictions with accuracy would be of great value in petroleum production and refining. Although the behavior of the methane-propane system' served at one time as a qualitative illustration of the probable characteristics of the more complex hydrocarbon mixtures found in nature, it' fell far short of requirements for quantitative predictions. The present paper endeavors to indicate the relation of the more recently accumulated information concerning the behavior of binary and ternary hydrocarbons to this problem. In discussing binary and ternary systems as examples pointing toward the behavior of multi-component systems no effort is made to present new methods of predicting the characteristics of natural hydrocarbon mixtures. Preliminary proposals have been made elsewhere for the prediction of volumetric phase equilibrium and thermodynamic data for multicomponent mixtures, utilizing as a basis the behavior of binary and ternary systems. Numerous other proposals have been made. That based upon the concept of a pseudo-critical state" has proved to be of value to the petroleum industry. Concurrently with this study of binary and ternary systems investigations have been made of natural hydrocarbon systems. Of the many publications reporting such experimental information only a few examples will be mentioned. A number of studies of black oil and natural gas have been made and much attention has been directed to extended and detailed investigations of the behavior of fluids in condensate fieldS 16,17,18,19,20. This work has been supplemented by some studies of the separation of bitumen from natural hydrocarbon liquids The over-all behavior of such systems has been used in predicting the volumetric and phase behavior of naturally occurring mixtures This background of experimental and correlated information concerning the behavior of multicomponent hydrocarbon systems also permits a direct comparison of the characteristics of binary and ternary aliphatic systems with those materials produced from underground reservoirs. PRESENTATION OF DATA The primary limitation encountered in using binary and ternary aliphatic hydrocarbon mixtures as examples of the characteristics of the fluids encountered in underground reservoirs lies in the existing lack of knowledge of the quantitative effect upon behavior of the presence of several important constituents, notably hydrocarbons of high molecular weight, water, carbon dioxide, hydrogen sulphide, and nitrogen. The presence of substantial quantities of hydrocarbons of fairly high molecular weight serves to increase the complexity of the phase behavior of natural systems. No simple systems yet studied give adequate guidance in this regard. The influence of such materials of high molecular weight was indicated earlier",?' to an extent which serves to show that definite limitations now exist in the correlation of simple and complex systems. However, significant progress is being made in filling gaps in the information. For example, similarities in the behavior of fluids in condensate fields with that of binary and ternary systems are becoming more systematically evident. A few studies of the behavior of water in paraffin hydrocarbon systems have been made Results of investigations of mixtures of carbon dioxide and the lighter hydrocarbons also are available Limited work has been reported con-

Jan 1, 1949

The attached tables show that in 1935 production of crude oil in Poland slightly decreased (minus 14,450 tons) and that gas production

Jan 1, 1936

The attached tables show that in 1935 production of crude oil in Poland slightly decreased (minus 14,450 tons) and that gas production

Jan 1, 1936

By Joseph Pogue

THE writer visited the Muzo emerald mines in July, 1915, and spent six days in their study. This paper embodies the results of his observations, plus information personally communicated by Robert Scheibe, FIG. 1.-SKETCH MAP SHOWING APPROXIMATE LOCATIONS OF ALL IMPORTANT EMERALD MINES AND PROSPECTS IN COLOMBIA. (Data in part supplied by Robert Scheibe, July, 1915.) Professor of Geology in the Mining Academy of Berlin, who at the time of the visit was completing a detailed field investigation of nearly a year's duration of the emerald deposits of Colombia. An elaborate account of this valuable work may be expected at a future date from the pen of Professor Scheibe.

Jan 5, 1916

By C. Ernest Birchenall, Robert F. Mehl

Application of diffusion laws in the customary form to experimental studies in binary metallic solid solutions has shown the diffusion cocfficient to vary with concentration for all systems investigated. The factors determining this variation have not been ascertained. However, the question of whether the diffusion coefficient would become a constant, independent of concentration throughout a single phase if the concentration gradient in the diffusion equation were replaced by an activity gradient has been an attractive subject for speculation. Wagner¹ derived an expression for the force acting on a diffusing particle in terms of the chemical potential. This was also the approach chosen by Jost2 in his monograph. From a somewhat different point of view, Eyring3 and his co-workers have used activity gradients when dealing with diffusion in concentrated nonideal solutions. The only actual test with experimental data is that given by Darken,4 though this is more qualitative than quantitative. Many others opposed the application in any way of thermodynamic concepts to kinetic phenomena, including diffusion processes. A rigorous examination of this principle requires good data expressing the relationship between activity and concentration for solid solutions for which reliable diffusion work has been done. The literature provides such information only for the interstitial solution of carbon in gamma iron (austenite) and for the substitutional copper-zinc solutions (alpha brass). Activity data for carbon in austenite at 800°C and 1000°C are available from the recent work of Smith5 on the equilibrium of hydrogen-methane and carbon monoxide-carbon dioxide mixtures with gamma iron. Combining these with the diffusion studies of Wells and Mehl6 makes possible a quantitative test for this interstitial solid solution. The vapor-pressure determinations for zinc over brass by Hargreaves7 allowed the calculation of activities in this system over a wide range of temperatures and concentrations. Extensive investigation of diffusion in this substitutional solid solution has been carried out by Rhines and Mehl.8 Activities in Brass9 If the vapor phase of zinc is assumed to behave as an ideal gas, any solid or liquid solutions that are in equilibrium with the same partial pressure of zinc at the same temperature have the same thermodynamic activity of zinc. In order to assign a numerical value to the activity azn, it is necessary to choose some standard reference state to which an activity value of unity is arbitrarily assigned. It is customary to choose the liquid or solid state of the pure material. Then azn is defined numerically by

Jan 1, 1947

By C. Ernest Birchenall, Robert F. Mehl

Application of diffusion laws in the customary form to experimental studies in binary metallic solid solutions has shown the diffusion cocfficient to vary with concentration for all systems investigated. The factors determining this variation have not been ascertained. However, the question of whether the diffusion coefficient would become a constant, independent of concentration throughout a single phase if the concentration gradient in the diffusion equation were replaced by an activity gradient has been an attractive subject for speculation. Wagner¹ derived an expression for the force acting on a diffusing particle in terms of the chemical potential. This was also the approach chosen by Jost2 in his monograph. From a somewhat different point of view, Eyring3 and his co-workers have used activity gradients when dealing with diffusion in concentrated nonideal solutions. The only actual test with experimental data is that given by Darken,4 though this is more qualitative than quantitative. Many others opposed the application in any way of thermodynamic concepts to kinetic phenomena, including diffusion processes. A rigorous examination of this principle requires good data expressing the relationship between activity and concentration for solid solutions for which reliable diffusion work has been done. The literature provides such information only for the interstitial solution of carbon in gamma iron (austenite) and for the substitutional copper-zinc solutions (alpha brass). Activity data for carbon in austenite at 800°C and 1000°C are available from the recent work of Smith5 on the equilibrium of hydrogen-methane and carbon monoxide-carbon dioxide mixtures with gamma iron. Combining these with the diffusion studies of Wells and Mehl6 makes possible a quantitative test for this interstitial solid solution. The vapor-pressure determinations for zinc over brass by Hargreaves7 allowed the calculation of activities in this system over a wide range of temperatures and concentrations. Extensive investigation of diffusion in this substitutional solid solution has been carried out by Rhines and Mehl.8 Activities in Brass9 If the vapor phase of zinc is assumed to behave as an ideal gas, any solid or liquid solutions that are in equilibrium with the same partial pressure of zinc at the same temperature have the same thermodynamic activity of zinc. In order to assign a numerical value to the activity azn, it is necessary to choose some standard reference state to which an activity value of unity is arbitrarily assigned. It is customary to choose the liquid or solid state of the pure material. Then azn is defined numerically by

Jan 1, 1947

By R. F. Lynch, J. D. Wood

The Al-1.0 pct Mg alloy 565 7 was studied using optical microscopy and electron microprobe X-ray analysis. Constituent particles were found to exist inter-dendritically in the as-cast material in a region of precipitate free a -aluminum. Five phases besides a fine precipitate and a-Al were identified in the cast structure: Fel3, Fe2Al7, Mg2Al3, CUMgAl2, and Cu2FeAl7. Thermal treatments conducted for 100 hr at 1180°, 1130°, 1080°, 1030°, 980°, and 880° F revealed a general dissolution and spheroidization of the in-terdendritic constituent network observed in the cast structure. The principal constituents present in the thermally treated structures were FeAl3 and Fe2Al7 with the relative amount of Fe2A17 to FeAl3 increasing with a decrease in the treatment temperature. The phases Present in the wrought structure were identical to those observed after the thermal treatments, with the constituent particles strung out in the direction of rolling. ALLOY 5657 is a nonheat-treatable commercial purity Al-1.0 pct Mg alloy utilized extensively because of its bright finishing characteristics. This investigation was conducted to determine the constituents present in 5657 alloy, and to study the effect of extended thermal treatments on morphology. Numerous studies have been carried out to establish the equilibrium diagrams for various aluminum systems,1-3 with phase identification based on X-ray analysis, morphology, and the etching response of relatively large particles. Phragmen4 conducted a study of the phases in aluminum eutectic systems and compiled a "corrected" table of etching responses, drawing on his work plus that of Schrader,5 Keller and Wilcox,6 and Mondolfo.7 A review of the original work of Keller and Wilcox, and Mondolfo, which was concerned with the constituents found in commercial alloys, reveals that in numerous cases their etching responses differ from those reported by Phragmen and from each other. These inconsistencies may occur because a specific constituent will react to a given etch in a varying manner depending upon its size, the elements dissolved in the phase, the other constituents surrounding a phase, and the solute content of the matrix. Work with a commercial orientation was conducted on alloys 2024 and 3003 by Sperry8,9 and on alloy 3003 by Barker,10 where the relationship between the phase diagram and the nonequilibrium structure of an alloy was examined. Backerud11 investigated the A1-Fe binary system and found that at high cooling rates the equilibrium eutectic reaction forming a-A1 and FeA13 is replaced by another lower temperature eutectic reaction forming a-A1 and metastable FeAl6, a constituent first identified by Hollingsworth et al.12 Most of the above mentioned studies were conducted on materials having a significantly greater alloy content than 5657 alloy, where the relatively small size and sparse distribution of second phase particles hinders the process of identifying constituents. EXPERIMENTAL PROCEDURE Material with a composition as given in Table I was examined in the as-direct chill cast, hot rolled and cold rolled conditions, and after thermal treatment of the cast structure. Thermal treatments were terminated by a water quench. Microscopic examination was conducted under various lighting conditions following the application of standard etchants as specified in Table 11. A semi-quantitative electron microprobe X-ray analysis was conducted for Al, Mg, Fe, Cu, Si, Zn, and Ti. RESULTS AND DISCUSSION Microstructure of the As-Cast Material. Particles of second phase material were found to exist inter-dendritically, principally in regions of precipitate free a-Al, as illustrated in Fig. 1. Adjacent to the ingot edge was a region of inverse segregation, resulting in an increased amount of second phase material containing large sized particles which aided in phase identification. Phase Identification. Cast Structure. Five phases besides a-Al and a fine precipitate were identified using optical microscopy and electron microprobe X-ray analysis, as presented in Tables II and III, respectively. FeA13 and Fe2A17 are often found with Fe2A17 forming a sheath around the core of FeAl3, resulting from an incomplete peritectoid reaction. These phases have a nearly identical appearance under white light, although they are easily differentiated under crossed polarizers, as characteristically illustrated in Figs. 2(a) and 2(b), respectively. Microprobe analysis con-

Jan 1, 1970

By F. A. Forward, V. N. Mackiw

The paper relates to the laboratory and pilot plant studies that have been carried out by Sherritt Gordon Mines Ltd., Metallurgical Research Div., in developing the ammonia pressure leach process for extracting copper, nickel, cobalt, and sulphur from high grade nickel concentrate produced from Lynn Lake ores, and describes in some detail the chemistry of the process. IT is well known'.' 2 that copper, nickel, cobalt, zinc, ferrous iron, and a number of other metals combine with ammonia in aqueous solution to form complex ions of the form [Me(NH,)x]"+. The stability and solubility of these ions depend on the concentration of the metal ion in solution, on the amount of NH, present, and on the amount and type of anions present, e.g., OH-, C0;-, NO,, C1-, SO;-. If ammonia is partially or completely removed from such solutions, for example by boiling, the soluble ammines tend to decompose and the metals precipitate as basic salts. These properties of metal ammines have found practical application in the commercial recovery of copper, nickel, and cobalt from a variety of ores. In an operation formerly conducted at Kennecott"" the mill tailing containing 0.80 pct Cu as copper carbonate was leached by percolation with an ammonia-ammonium carbonate solution to dissolve the copper as the ammine. At Calumet and Hecla0-" With a mill tailing containing about 0.4 pct Cu as metallic copper, it has been found necessary to aerate the ammonia-ammonium carbonate leach solutions between stages to oxidize the solubilized copper. At Nicarol"-" where nickel and cobalt occur as oxides and silicates which are not soluble in ammonia, the ore is heated to decompose silicates and to selectively reduce the nickel and cobalt to metal, leaving the iron as Fe,O,, and is then leached with ammonia-ammonium carbonate solution accompanied by aeration to dissolve nickel and cobalt as ammines. In each of these leaching operations, the anion present is CO, and the metals can be precipitated from the leach solution as oxide (copper) or hydroxide and carbonate (nickel and cobalt) by boil- ing off NH, and C02 both of which are recycled to treat a subsequent ore charge. The products-—oxide, hydroxide, or carbonate—can be treated by conventional smelting, calcining, or electrolytic methods to convert them to refined metals. Thus the procedures mentioned utilize the properties of the ammines to extract copper, nickel, and cobalt from nonsulphide ores and separate them from the leach solutions. These processes have the advantage that they can be carried out in closed vessels at atmospheric pressure, that the leaching solutions are specific for the desired metals, that the metals can be recovered as relatively pure compounds by the boiling operation, and that the NH, and CO, can be recycled. Also, as the leach solutions after boiling and filtration are substantially free of metals, NH,, and CO,, they can be discarded, thus facilitating the control of the water balance in the leaching circuit. When, as is the case with Sherritt Gordon concentrates, sulphides are treated with ammonia solution in the presence of oxygen, the leach solution contains SO,--, and an entirely different set of conditions is encountered. The ammine sulphates (of nickel, for example) are more soluble than the carbonates and can be only partially decomposed by boiling. The SO, and NH, in the solutions can not be recovered by boiling. Thus, despite the more favorable leaching conditions resulting from high solubility of the ammine sulphates, the recovery of metals, NH,, and SO, from the solutions must be effected by other means. Sherritt Gordon Nickel Concentrate Treatment The Ni-Cu-Co flotation concentrate produced at Lynn Lake'" contains 12 to 16 pct Ni, 1 to 2 pct Cu, 0.2 to 0.5 pct Co, 33 to 40 pct Fe, 28 to 34 pct S, 8 to 20 pct insoluble, and less than 0.02 oz per ton precious metals. The nickel is present chiefly as pentlandite, the copper as chalcopyrite, and the iron as pyrrhotite and pyrite. Most of the cobalt is thought to be present in pentlandite, although it is known that a small amount occurs as Co-Ni-pyrite.

Jan 1, 1956

By Marston G. Fleming

E. C. Peterson (Anaconda Copper Mining CO., Darwin, Calif.)—A study of this quite comprehensible and interesting paper by Dr. Fleming brings to mind several observations in the practical application of alkalinity and related factors to the actual practice of lead mineral flotation. Soda ash has long been a widely used and a very helpful alkaline conditioning agent in the flotation of galena from the usual run of lead-zinc ores. Soda ash is one of the common "standard" conditioning agents tried in any laboratory investigation of lead-zinc ores because it has so often proved helpful to galena flotation. However, the use of soda ash in the actual flotation of oxidized lead ores is certainly not widespread. In the flotation of certain lead-zinc ores from the Park City district of Utah, it was found in the usual cyanide-zinc sulphate-xanthate circuit that soda ash had an effect of producing a very condensed and flat froth regardless of the many frothers tried and that substitution of lime for soda ash to produce the same pH (8.0 to 8.4) improved the froth condition. However, the flotation of coarse particles of galena became so critical that some would pass through into the tailing, but caustic soda as a substitute for either soda ash or lime produced a very desirable froth condition in the same pH range and greatly improved the metallurgical outcome. Milling was carried out in typically "hard water" from watersheds of limestone and other calcareous rocks and the ore also apparently contributed magnesium and calcium salts to the pulp. Certain lead-zinc ores of Mexico have shown their greatest flotation response in circuits conditioned with sodium bicarbonate, and such actual mill use was also believed to be related to the water necessarily used in milling. On other lead-zinc ores the optimum has been obtained in actual milling treatment by use of caustic soda in both circuits of the operation. In flotation of oxidized lead ores in which sulphidi-zation is employed by addition of sodium sulphide, very high pH's exist in the flotation circuit. With the usual oxide lead ores, demanding 5 to 15 lb of sodium sulphide per ton of ore, pH's in the circuit (closed and open water-circuits) may range from 9.5 to 12, and for ores that contain much anglesite or a high percentage of iron oxide minerals, sodium sulphide consumption may reach as much as 30 lb per ton of ore and the resultant pH will be correspondingly higher. Yet in such flotation treatment employing either xanthate or oil (high-sulphur crude oil or diesel oils) as the collector, satisfactory to excellent grades of concentrate and lead recovery are obtained. Although there have been great studies and accomplishments in the investigations of flotation fundamentals and flotation theory, and although an investigation to determine the effect of all factors entering into the actual plant flotation of sulphide and oxide ores must become very complicated, as Mr. Fleming has mentioned in his caution regarding the drawing of general conclusions for other ores, it seems that it would be of greater interest if the techniques and investigations could, with time, approach the conditions of actual practice and lead the way to improved and more efficient flotation plant performance. Marston G. Fleming (author's reply)—The gulf between fundamental flotation research and plant operation is, perhaps, less wide than Mr. Peterson suggests. For example, the work described in my paper developed from an extensive investigation of a complex lead-vanadium ore from southwest Africa. This investigation started as a standard ore-testing problem but, at almost every stage, results were obtained which could not be interpreted in terms of previous experience. A program of fundamental research was therefore undertaken and was closely interlocked with the ore testing. This coordinated investigation resulted in a flotation process which has now been proved by two years of successful plant operation, and although the grade and mineralogical constitution of ore as well as smelter requirements have altered more than could have been anticipated, our knowledge of the fundamental character of the problem has made it possible to meet each change in conditions with much more confidence than would have been the case had we neglected this aspect of the investigation.

Jan 1, 1954

By D. M. Warner, Samuel Daniels

In this paper are given the mechanical properties, determined by the Engineering Division, Air Service, U. S. A., of the 94 per cent. aluminum, 5 per cent. copper, 1 per cent. silicon alloy as 8and-cast and as heal-treated commercially to Air Service Specification No. 11,300. This particular alloy was tested both in the cast and in the heat-treated condition. Tension and tension modulus values were obtained from machined and from un-machined test specimens; while data for shear, compression, impact, torsion, and for Brine11 and Rockwell hardness were found from machined bars. Specific-gravity tests were made on sanded, un-machined specimens. The metallography of the alloy is useful as a control to heat treatment and presents some interesting peculiarities in regard to the two iron-bearing compounds. The demand for an aluminum alloy, suitable for sand castings, that may be heat treated to meet requirements of high strength, ductility, shock and corrosion resistance, and ready machineability has led to the commercial development of a proprietary material that contains from about 4 to 5 per cent. of copper, 1 per cent. of silicon, and such impurities as iron, up to a maximum of 0.75 per cent., and manganese, in quantity usually less than 0.1 per cent.' Magnesium is not generally present, for it tends to nullify the beneficial influence of the added silicon by forming magnesium silicide. The function of the silicon is to minimize casting difficulties and, structurally, to favor the precipitation of (insoluble) iron-bearing skeletons rather than the needles, which prevent full realization of tensile properties from heat treatment by stimulating intergran-ular fracture. The amount of silicon necessary to counteract the ill effect of iron is equal to or slightly more than the content of iron; the excess of silicon over this ratio, under certain conditions of heat treatment, enters with CuAl2, the principal hardening constituent, into solid solution and contributes somewhat to the strength of the alloy without appreciably impairing its ductility. The schedule of heat treatment of this alloy depends on the design (cross-sections) of the castings and on the nature of the tensile properties desired. Essentially, the process consists in heating the material at about 950" F., quenching in oil or in cold or boiling water, and artificially aging

Jan 1, 1926

By Lo-Ching Chang, Kenneth M. Goldman

INTRODUCTION THE kinetics and mechanism of transfer of a constituent across a slag-metal interface are fundamentally important because many metallurgical processes involve the existence of a slag phase and a metal phase. Industrial processes seldom proceed to equilibrium, and information of the rates and modes of reactions are therefore often of greater practical importance than equilibrium data. A study of the kinetics of sulphur transfer across a slag-metal interface under reducing conditions will contribute a great deal toward a better understanding of desulphurization in the blast furnace process. The general principles existing in the transfer of a constituent, such as sulphur, across a slag-metal interface can be extended to similar transfer phenomena in other metallurgical processes. The present paper will demonstrate how such studies will lead to fruitful results from both the practical and theoretical standpoints. EXPERIMENTAL METHOD The apparatus used was simple. A graphite crucible 1 5/8-in. id, a wall 1/8-in. thick, and a depth of 4 in., was packed in an outer fused silica tube with powdered magnesia. The crucible assembly was rotated at a speed of 235 rpm inside an induction coil. A charge of 250 g of Armco ingot iron was introduced into the graphite crucible and melted by induction heating. The melt was held at a desired temperature [ ] for 3-5 min., after which 7.5 g of granular ferrous sulphide was added and the bath was held for another 3-5 min. A metal sample was then taken by means of a fused silica tube and a rubber suction bulb. Immediately after the metal sample was taken, 30 g of a prefused and crushed slag were introduced. The slag reached the temperature of the furnace in 1 to 1 1/ 2 min. Slag

Jan 1, 1948

By D. I. Bardos, F. X. Spiegel, R. K. Malik, Paul A. Beck

Study of the occurrence of elongated ß-Mn phase fields and of their direction of extension in fifteen ternary systems indicates that the ß-,mn phases formed by manganese with other transition elements and with either silicon, germanium, or tin may be considered as electron phases. In these phases the alloying behavior of silicon on the one hand and of germanium and tin on the other shows a significant difference . Formally all observations can be satisfactorily described by attributing to germanium and tin an apparent electron concentration of nine electrons per atom. This behavior may be interpreted by assuming that germanium and tin exclude itinerant electvons because of a strong repulsive potential arising fromthe requirement that their wave junctions be orthogonal to those of- the closed d shells of these atoms. The absence of a d shell in silicon allows this atom to admit itinerant d electrons. The following new ternary phases of unknown structure were identified by means of their X-vay difjraction patterns: (Mn,Co,Si)I , (Mn,Co ,Si)Y, (Mn.Co,Si)Q , (Mn ,Ni ,Si)W , and (Mn, Ti ,Si)A. The X-ray data suggest that these phases have large unit cells and that to some extent they may he related structurally to the 0 phase. The a phase and certain other phases formed by transition elements are characterized by their preferred occurrence at a constant electron concentration. AS a result, these "electron phases" have relation to electron concentration. The tendency of the B phase to form elongated phase fields in ternary systems along the directions of constant electron concentration has been previously demonstrated. The occurrence of an elongated 0-Mn phase field in the ternary system Mn-Co-Si was schematically indicated by Cherkashin et al.l0 The present study includes fifteen ternary systems, each containing in addition to manganese a second transition element from the group Ti, V, Cr, Fe, Co, Ni and one of the nontransition elements silicon, germanium, or tin. In each system the boundaries of the B-Mn phase were determined in the 900°, 950°, or 1000°C isothermal section, the temperature being dictated on the one hand by the requirement of sufficient rates of diffusion to approach equilibrium conditions in reasonably short annealing periods and on the other hand by the need to avoid as much as possible the partial melting of alloys during annealing.

Jan 1, 1967

By Donald E. Grimes

In conjunction with Inland Steel&apos;s development of lead-bearing steels possessing improved machin-ability because of tellurium and/or selenium additions, it was decided to determine liquidus and solidus temperatures in the Pb-PbTe-PbSe sub-ternary system. With the exception of alloys in the PbTe-PbSe system, it is believed that no previous study of this subternary has been performed. Thermal analysis was employed in a general survey of the subternary. In addition to PbTe, PbSe, and pure lead, ten ternary compositions were selected at intervals of ten at. pct. Sixty-gram alloys were prepared by sealing an appropriate mixture of the elements in quartz crucibles with a central thermocouple-well under a vacuum of less than 10 p. All three elements were 99.999+ pct pure with only trace impurities detected by spectroscopic examination. After the alloys had been heated at least 20°C above the liquidus in a Kanthal furnace, cooling and heating curves were obtained. Two or more cooling curves were employed both for the determination of each alloy liquidus and for the solidus of those al- loys containing greater than 50 at. pct Pb. Cooling rates were 0.5° to 3.5°C per min during the 5 min immediately prior to the start or end of solidification. For those ternary alloys containing 50 at. pct Pb, the solidus was determined from heating curves. Temperatures were measured with a Pt/Pt-10 pct Rh thermocouple which was calibrated in the same apparatus against the freezing points of zinc (A. D. MacKay—99.999 pct), antimony (A. D. MacKay-99.999 pct), and copper (ASARCO—99.999+ pct) both before and after the experimentation. The only interruptions in the continuous strip-chart recording of the temperature occurred for brief periods at significant points of interest when direct readings were made with a Rubicon Type B potentiometer sensitive to * 1 µv. The average liquidus and solidus temperatures obtained in this investigation are listed in Table I together with probable errors based on the accuracy of the thermocouple calibration and the reproduci-bility of the data. No chemical analyses of the alloys were performed because the synthetic or as-charged compositions were felt to be reliable. The melting points obtained for PbTe (924.7° ± 0.7°C) and PbSe (1084.0° ± 0.6°C) compare favorably with recent findings of other investigators.&apos;-&apos; As indicated in Table I, both the liquidus and solidus temperatures increase as selenium replaces tellurium for a constant atomic percent lead. As a result, the ternary liquidus and solidus temperatures for a given percent lead lie between the corresponding binary temperatures published in the literature. It should be noted that those ternary alloys containing 50 at. pct Pb exhibit a relatively narrow liquid-plus-solid region (<80°C) when compared with alloys containing greater than 50 at. pct Pb. Alloys with 60, 70, or 80 at. pct Pb not only have a much wider liquid-plus-solid region (>500°C) but also exhibit considerably lower and approximately constant solidus temperatures which thus form a virtually isothermal solidus "plane" slightly below the melting point of pure lead (327.3°C). For these alloys

Jan 1, 1965

By B. Hyatt, E. Klokholm

The reesistivity of Cu-Pd alloys of 9.6 to 29 pct Pd alloys was measured after plastic deformzation in tension. For all compositions a continzting decrease in resistivity with increasing plastic strain was observed. By comparison with the results of Damask on a brass ad Cu3Au, it was deduced that these anonzalous decreases in resistivity are due to the decrease in short-vunge order caused by cold work. An anomalous decrease in the resistivity of cold-worked CU-Pd alloys was first reported by Jaumot and Sawatzky.&apos; They observed decreases in the electrical resistivity when disordered Cu-Pd alloys drawing at room temperature. Recently, a similar anomaly was reported by Aarts and Houston-Mac-Mi1lan2 in Ag-Pd alloys containing 10 to 45 pct Pd. The plastic deformation in this case was produced by tensile strain at liquid-nitrogen temperatures. For AE-Pd alloys the relative resistivity change becomes positive for tensile strains of about 20 pct.

Jan 1, 1960

By G. J. Heuer, J. N. Dew, G. C. Clark

The effect on well behavior of partial permeability barriers, changes in producing rates and well spacings have been calculated through use of a radial, unsteady-state, two-phase-flow mathematical model. This model allows for variations in permeabilities and porosities with distance from the wellbore. The numerical methods necessary to solve the problem require use of a highspeed digital computer, in this case an IBM 704. In each instance, pressure and saturation gradients, gas-oil ratios and recoveries around a well producing by solution-gas drive have been calculated as a function of time and distance from the wellbore. Comparisons are made to show the effect of changes in producing rate and of varying permeability near the wellbore and out in the formation on the production and pressure history of the well. The effect of different well spacings on producing rate and ultimate recovery is considered. Although the mathematical description of the reservoir is simplified in comparison to an actual reservoir, the results do give some insight into the difficult problem of spacing and proration in a heterogeneous solution-gas-drive reservoir. Results show that for the cases considered spacing has little effect on ultimate recovery and that permeability barriers removed from the well decrease producing rate for a period of time but have only a small effect on ultimate production. INTRODUCTION The effect of spacing and producing rate on the production characteristics and ultimate recovery of a well producing by the solution-gas-drive mechanism have been topics of interest to the oil industry for many years and the subject of many hearings before state regulatory bodies. The problem is very complicated because of the difficulty of simulating in the laboratory a reservoir producing by the solution-gas-drive mechanism under anything like normal field conditions. This paper gives the initial results of a study aimed at determining the effect of these factors on production from reservoirs simulated by a mathematical model. Two-phase, unsteady-state equations are used to calculate pressures, saturations, and rates of oil and gas flow as a function of time and distance from the wellbore. The model is radial, and reservoir properties may be varied with distance from the wellbore. A decrease in permeability at a given distance results in a low-permeability ring concentric with the wellbore through which all the fluids from more distant portions of the reservoir must flow. The current mathematical model allows for variation of permeability, porosity and saturations as a function of distance from the well. Any desired drainage radius for the well may be selected. Drainage radii of 745 and 1,053 ft, which correspond to 40- and 80-acre spacing, were chosen for the calculations which follow. A large amount of the input data has been held constant. No investigation was made into the effect of changes in fluid properties and relative permeability characteristics on oil and gas production behavior. Fluid properties and relative permeabilities are essentially those of the White Mesa portion of the Greater Aneth area in southeastern Utah. A recently concluded hearing before the Utah Oil and Gas Conservation Commission to determine spacing for the field aroused interest in the possible effect of permeability constrictions located some distance from the well on production and recovery. This interest stimulated the present study. In this paper, no attempt has been made to simulate any field production characteristics exactly. Only the solution-gas-drive mechanism has been investigated, and production by liquid expansion has not been considered. This investigation is exploratory in nature but does give some insight into the problems of spacing and proration in a solution-gas-drive field having permeability variations. THE MATHEMATICAL MODEL The mathematical model is similar to that proposed by West, Garvin and Sheldon.&apos; Approximately the same techniques have been used in arriving at a solution. The equations are nonlinear, partial differential equations which have been known for some time. The particular equations used for this study neglect the effects of capillary pressure and gravitational forces. The advent of modern digital computing equipment has made their solution practical. Basically, the method solves for pressure, saturations, and oil and gas flow rates as a function of distance and time. In our model, distance to the

By S. T. Wlodek

The scale md subscale reaction products were identified and their rates of formation were studied in air over the range 1600" to 2000°F (871 " to 1149°C) for periods of up to 400 hr and for hoth the solution-annealed and aged conditions. The effect of prior sltrface preparation on suhscale oxidation was also studied The general oxidation behavior of both Ni-Cr-Mo-Al-Ti type alloys was similar. A surface film of a, Al2O3, forms immediately on exposure Subsequent oxidation continued at a linear rate (QL = 55 * 5 kcal per mole) as colonies of Cr2O3 nucleated at the A12O3/gas interface Further oxidation proceeded at a paraholic rate zvhiclz could he fitted to two successive rate constants. During paraholic oxidation, and depending on temperature, the scale consisted of Cr2O3, NiCr2O4 , and TiO2 with traces of NiO. In the case of Rene 41, the activation energy of both paraholic processes was 66 * 3 kcal per mole suggesting that diffusion of cations tlzrozrgh Cr2O3 was the rate -determining process. An unusual decrease in the oxidation of Udimet 700 at 1900°F where a spinel of Ni(A1,Crh0, zuas the predominant reaction product prevented the accurate assignment of activation energies for this composition. In both alloys internal oxidation of Al2O3 commenced shortly after parabolic scaling was observed. Prolonged exposure prod7tced intemal oxidation of TiN, and in Udimet 700 a complex Mo-Ni nitride was also found. At 1900oF, the subscale reactions in Udimet 700 undergo an inversion which parallels the decrease in surface oxidation; internal oxidation ceases hut is replaced by the formation of "spherodized" 3.&apos; colonies. Surface-preparation techniqtles which introduce appreciable working, such as coarse surface grinding or grit blasting. increase the amount of alloy depletion and internal oxidation in Reni 41. The reverse is true of Udimet 700 for which electropolished or mechanically polished specimens show much more subscale oxidation than strongly worked stirfaces. The strongest commercial nickel-base alloys presently available are generic to the Ni-Cr-Mo-A1-Ti base which exploits the precipitation of Ni3(A1,Ti) as the main strengthening mechanism, while relying on solid-solution strengthening by molybdenum and chromium reinforced by the pre- cipitation of carbides to attain maximum properties. This study characterizes the oxidation behavior of Rene 41, the strongest alloy of the Ni-Cr-A1-Ti type commercially available in sheet form, and Udimet 700, whose higher aluminum and titanium content allows it to exhibit one of the more attractive combinations of high-temperature properties available in a wrought product. The scaling processes of complex, type nickel-base alloys have received relatively little attention. Malamand and vidal as well as Poulignier et al.2&apos;3 have determined the composition gradients across the metal/oxide interface produced by high-temperature oxidation and considered the effect of surface perature, Limited weight-gain data has also been published by Fere 5 for alloys of this type and Radavich6 has identified the reaction products on Udimet 500 and Inco 702 after oxidation at 1832°F. Reference can, of course, be made to the excellent reviews of Kubaschewski and Hopkins7 or Ignatov and Shamgunova8 for a summary of the data available on the oxidation of binary and ternary alloy systems which are related to the more complex alloys considered here. EXPERIMENTAL The analyses of the different commercial heats studied are given in Table I. Using the experimental procedures previously established,9 continuous weight-gain data were obtained on both heats of Rene 41 sheet (A and B) and 150-mil-thick slices of cast Udimet 700. Subscale oxidation reactions were followed by static exposure of cylindrical specimens obtained from swaged Rene 41 (Heat C) and Udimet 700 (Heats E and F). In brief, continuous weight-gain tests were performed on specimens with a surface area of 10 to 12 sq cm. These were abraded through 600 grit Sic paper, electropolished to 2p rms in an electrolyte of 10 pct H2So4 in ethanol, and lightly etched in 10 pct HCl in ethanol before final washing and rinsing in ethanol. All continuous weight-gain data were obtained in dried (-70°F dew point) flowing (1 liter per min) air to an accuracy of +0.1 mg. Subscale oxidation processes were followed by the metallographic examination of 0.5-in-diam by 1.0-in.-long specimens. After an initial center-less grinding, various additional surface treatments were employed to determine the effect of surface preparation on subscale oxidation processes. Before exposure in zirconia crucibles, all samples were lightly etched in 10 pct HCl-ethanol, washed in ethanol, and dried. The depth of internal oxidation was measured to ±0.00025 in. on unetched specimens mounted so as to provide a taper mag-

Jan 1, 1964

By John M. Campbell, W. E. Portman

A series of correlating charts have been prepared to enable the field engineer to predict the amount of stock tank fluid produced by stabilization of first stage separator fluid. The charts shown are particularly convenient for estimating the relative effect of temperature and pressure in economic studies. Further work is planned to investigate the factors affecting stage separation&apos; yo supplement this preliminary work. The direct correlation of separation variables is dictated as a convenience to eliminate the trial and error calculation necessary when using the standard flash vaporization equations. These are obtained by a material balance using the equilibrium vaporization ratio K, and have appeared in the following, or similar. form many times in the literature. where La = mols of any component n in the separator liquid Ko — equilibrium vaporization ratio for any component at separator pressure and temperature Fa = mols of any component n in the feed Vn = mols of any component n in the vapor V = total mols of separator vapor These equations may of course be effectively and accurately solved by use of digital and analog computers. However, these are not usually readily available in field offices and the need often arises for fast results during routine operational problems. Consequently, many methods have been devised in an attempt to simplify the basic calculation.2-14 The methods proposed are generally satisfactory, but do not eliminate trial and error methods and the necessity of subsequent calculations to obtain the answer in volume terms. The purpose of this work. therefore, was to develop accurate charts that would give the result directly in gallons. When using stage separation the recoveries would be lower than those shown, for stabilization usually gives about 95 + per cent recovery on the potential stock tank components in the separator liquid. The recoveries are shown in terms of a 14 psi Reid Vapor Pressure product which has a true vapor pressure of 14.7 psia at 98°F. Consequently, this product represents a stable stock tank liquid under normal storage conditions. To estimate natural gasoline re- coveries by stabilization the volume shown may be multiplied by 1.20 for 18 Ib RVP natural gasoline and 1.36 for 26 lb RVP natural gasoline. PROCEDURE The five analyses shown in Table 1 were chosen since they were representative of wellstream compositions often found and had almost the same propanes plus liquid content, expressed in gallons per 1,000 std. cu ft of wellstream. The distribution of the components though is widely variant. A temperature range of 0-100°F. and a pressure range of 200 to 1,250 psia was chosen inasmuch as most separations fall within these limits The K values used were modified values of those originally published by Katz and Hachmuth.&apos; In the range chosen these have generally given good results when predicting fluid recoveries. The choice was somewhat arbitrary, for the authors&apos; personal experience has shown that

Jan 1, 1957

By K. Sassa, I. Ito

The dynamic principal stresses induced within rock by an explosion under con fined conditions are analyzed for the case of blasting with one free face by applying the values of measured radial displacement, particle velocity and so on to equations derived from the theory of elasticity. The dynamic stresses on the free face are also calculated from the strain measured by wire strain gauges affixed on the free face. Some results obtained are briefly: 1) The maximum stress on the free face appeared at the intersection between the free face and the burden, and its magnitude was about twice as large as the magnitude of the tangential tensile stress imparted by the incident stress wave within the range related to the breakage by blasting. 2) The maximum value of the compressive stress near the free face was decreased due to the existence of the free face, while that of the tensile stress was increased. 3) At any point near the free face, the directions of the principal stresses in the r? plane using spherical coordinates with the origin at the center of the spherical charge, changed with time except in the direction of the burden. However, at another point near the explosion point where the principal stresses were mainly those stresses caused by the initial longitudinal wave, the directions of the principal stresses coincided with those of the coordinate used. 4) The maximum value of the tensile stress in the F direction was larger than those in the re plane at and near the free face. 5) The tensile stress caused by the Hopkinson effect appeared only near the burden. 6) It is presumed from the results of stress analysis that radial cracks will be produced in the rock mass near an explosion point, but with the approach of the free face, the directions of cracks curve towards a direction parallel to the free face. INTRODUCTION In order to investigate the mechanism of rock breakage by blasting, it is considered to be very im- portant to know how the stresses are generated and distributed within the rock by explosion of a confined charge. As part of a research program concerning the mechanism of rock breakage by blasting, the authors have already published papers on the detonation pressure produced at the inner surface of the charge hole1 and on the behavior of the dynamic stresses within rock caused by an explosion in the case where no free face existed.&apos; In this study the dynamic stresses on and near the free face have been investigated for the case of blasting with one free face. The mechanism of rock breakage in blasting is discussed in the light of these studies.

Jan 1, 1967

By Lyall Zickrick

Numerous brands of virgin pig lead are used in the manufacture of lead and lead-alloy cable sheath for commercial cables. In changing from one brand of pig lead to another a readjustment of press operating conditions is nearly always necessary. This is due largely to different flow characteristics, and some brands extrude at a much lower pressure than others; for example, copper-bearing lead requires much more pressure than a low-bismuth lead under the same operating conditions. With the modern type of lead press the extrusion practice in general differs very little. Molten lead at a temperature of 375" to 400" C. (710" to 750" F.) is cast in a water-cooled cylinder and allowed to cool or solidify into a slug for six to nine minutes, This slug is forced into the die block and around the core tube through which the cable runs. The • die block is held at an optimum temperature by means of gas flames, usually 175" to 225" C. (350" to 435" F.). Measurements of the temperature of the cable sheath taken at the time of extrusion have covered a range of 190" to 225" C. (375" to 435" F.). According to Tammann, the rate of extrusion for a metal under constant pressure through a simple orifice is almost doubled for each 10" C. rise in temperature. Because of the irregularity of die-block construction, such a great increase is not obtained in lead-cable extrusion practice. To obtain more definite information about the effect of small percentages of metals usually present as impurities in virgin pig lead, a series of compression tests were made covering several different brands of lead and various alloys. Since the usual temperature of the sheath is approximately 200" C. as it emerges from the die block, these compression tests were all performed at 200" C. Five different brands of virgin pig lead were selected, as follows: Brand A: A desilverized western lead of very high purity. This lead contains neit,her copper nor bismuth. Brand B: A bismuth-free southeastern Missouri lead, usually containing 0.05 to 0.08 per cent copper. Brand C: A copper-free mid-western desilverized lead of very good grade, usually containing around 0.06 to 0.10 per cent bismuth.

Jan 1, 1932