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By C. Burton Clark, J. Spotts McDowell

Refractories are defined as "materials having the ability to retain their physical shapes and chemical identities when subjected to high temperatures," or as "nonmetallic materials suitable for the construction or lining of furnaces operated at high temperatures." While resistance to "high" temperatures is thus the primary requirement for refractory materials, it is by no means the sole requirement. They must be able to withstand thermal shock resulting from rapid heating or cooling; other stresses induced by temperature change; pressures from the weights of furnace parts or contents; mechanical wear (abrasion) resulting from movement of furnace contents; and chemical attack by heated solids, liquids, or gases. Refractories of many kinds are needed for the many and widely diversified industrial applications. Those in greatest demand are classified on the basis of composition or properties into a few main groups, known as alumina-silica, silica, basic and insulating refractories. In each of these groups there are several classes. In addition to those included in the main groups, there are various special refractories, including silicon carbide, carbon, zircon, zirconia, alumina, and several others. Alumina-silica refractories comprise two main divisions: fire clay and high-alumina. The alumina content of fire-clay refractories covers the range from about 45 pct to 18 pct, and the silica content from 50 pct to 80 pct. The alumina content of fired high-alumina refractories ranges from about 99 pct to 45 pct, and the silica content from about 0.5 pct to 50 pct. Silica refractories of the different classes contain 94 pct to 97 pct silica. Basic refractories include periclase (magnesite), chrome spinel, forsterite, and dolomite. Refractory materials, including insulating firebrick, are supplied mainly as preformed shapes. Other products include bonding mortars and high temperature cements, ramming mixtures, plastic firebrick, hydraulic setting castables, dead-burned grain magnesite, and dead-burned dolomite. Refractory brick are classified on the basis of their physical form as Standard Sizes and Special Shapes. The Standard Sizes are brick of certain definite sizes and relatively simple design which are used in sufficient amounts to permit quantity production. The brick most widely used are the standard 9 in. X 4 ½ in. X 2 ½in. and 9 in. X 4½in. X 3 in. straights and corresponding series of sizes. All brick of nonstandard dimensions are regarded as "special shapes." They include a wide variety of brick regularly used for specific services, such as baffle tile for boilers, checker brick for regenerators, and others; together with shapes of special design manufactured on particular orders from designs submitted by the user. Not included in the broad classifications of Standard Sizes and Special Shapes are several specific-service refractory products, usually made by companies which specialize in their manufacture, or in some cases by the consumers themselves. These products include

Jan 1, 1960

By D. H. Woodard, G. W. Geil, W. D. Jenkins

In a series of papers, the authors and their associates have shown the influence of four important factors on the technical cohesion limit.3-l6 By "technical cohesion limitv is meant the technically determin-able resistance to fracture. The four importarlt factors are the stress system, plastic deformation, temperature, and the strain rate, The influence of any one of these factors may be represented by a curve of cohesion limits, although only one point on the curve may represent actual fracture. As the term "fracture stress" has come into general use with the same significance as technical cohesion limit, the authors are here using the shorter term with the understanding that it does not always refer to actual fracture. The previously mentioned series of papers contains ample evidence that plastic extension increases the fracture stress of any polycrystalline metal, In a recent paper of the series,l5 moreover, it has been shown that the effect of plastic deformation on the fracture stress cannot be attributed to reorientation of internal flaws but is a work-strengthening effect, similar to the effect on the flow stress, $ Plastic deformation of steels, however, may not only cause work hardening, but may result in additional hardness because of strain aging. Some evidence that strain aging affects not only the flow stress but also the fracture stress, has been presented in a recent paper.14 In that paper, a study is made of the influence Of Plastic deformstion at room temperature on the fracture stress of ferritic steels at -188°C. The study is based on the results Of two-stage tests. In the first stage each specimen was extended a predetermined amount at room temperature; in the second stage the specimen was tested to fracture in liquid air. In most Of these tests the specimen remained in the testing machine during the interval of about one hour between the first and second stages, it was kept under a tensile load of about 500 lb and maintained at liquid air temperature. The effects of various amounts of .plastic deformation on the fracture stress were thus determined and curves were obtained to represent the influence of plastic deformation at room temperature on the stress at brittle fracture in liquid air.14 Two specimens Of ingot iron, however, were removed from the testing machine at the end of the first stage and several days elapsed before the specimens were tested to fracture in liquid air, As shown in Fig 8 of that paper," the points representing fracture of these specimens are far above the curve representing the results of two-stage tests without a rest interval between the stages. The evidence thus indicated that the fracture stresses of these two specimens were increased not

Jan 1, 1949

By G. W. Geil, D. H. Woodard, W. D. Jenkins

In a series of papers, the authors and their associates have shown the influence of four important factors on the technical cohesion limit.3-l6 By "technical cohesion limitv is meant the technically determin-able resistance to fracture. The four importarlt factors are the stress system, plastic deformation, temperature, and the strain rate, The influence of any one of these factors may be represented by a curve of cohesion limits, although only one point on the curve may represent actual fracture. As the term "fracture stress" has come into general use with the same significance as technical cohesion limit, the authors are here using the shorter term with the understanding that it does not always refer to actual fracture. The previously mentioned series of papers contains ample evidence that plastic extension increases the fracture stress of any polycrystalline metal, In a recent paper of the series,l5 moreover, it has been shown that the effect of plastic deformation on the fracture stress cannot be attributed to reorientation of internal flaws but is a work-strengthening effect, similar to the effect on the flow stress, $ Plastic deformation of steels, however, may not only cause work hardening, but may result in additional hardness because of strain aging. Some evidence that strain aging affects not only the flow stress but also the fracture stress, has been presented in a recent paper.14 In that paper, a study is made of the influence Of Plastic deformstion at room temperature on the fracture stress of ferritic steels at -188°C. The study is based on the results Of two-stage tests. In the first stage each specimen was extended a predetermined amount at room temperature; in the second stage the specimen was tested to fracture in liquid air. In most Of these tests the specimen remained in the testing machine during the interval of about one hour between the first and second stages, it was kept under a tensile load of about 500 lb and maintained at liquid air temperature. The effects of various amounts of .plastic deformation on the fracture stress were thus determined and curves were obtained to represent the influence of plastic deformation at room temperature on the stress at brittle fracture in liquid air.14 Two specimens Of ingot iron, however, were removed from the testing machine at the end of the first stage and several days elapsed before the specimens were tested to fracture in liquid air, As shown in Fig 8 of that paper," the points representing fracture of these specimens are far above the curve representing the results of two-stage tests without a rest interval between the stages. The evidence thus indicated that the fracture stresses of these two specimens were increased not

Jan 1, 1949

By Margaret Dienes, Karl L. Fetters

IT is recognized that ingot structure is important in determining the quality of finished steel. Such elements of ingot structure as the size, shape and distribution of primary crystals; the size, shape and distribution of shrinkage cavities; the degree and kind of segregation (both macro and micro); the distribution of nonmetallic impurities and gas cavities are each the result of solidification phenomena. These structural features vary with variations in ingot practice: Their control requires a knowledge of their correlation with the variables of ingot practice. The structures of full-sized commercial steel ingots have been studied extensively by the Steel Ingots Committee of the Iron and Steel Institute.1 This work has contributed much to our knowledge of ingot structure and the factors that control it. These investigations of necessity have been limited in scope because of their costliness and the great amount of time required. Studies of the structure of small steel ingots have not been very satisfactory because of the rapid rate of freezing of the ingots. Their structures are thus difficult to resolve and to interpret. Medium sizes of steel ingots in the ranges of 150 to 500 lb. do offer opportunity for study, but their cost also becomes greater and their use less expeditious. Experimental models for the study of steel-ingot structure have been made of nonferrous metals. Gathmann2 used lead-tin alloys and reported that they were satisfactory for determination of the location of the major shrinkage cavities and the "planes of weakness" resulting from the pattern of crystallization. Certain features of mold design have been illustrated by these results. Bezdenezhnihk3 has used copper and aluminum ingots similarly and has shown the effect of mold-wall thickness on the depth of columnar grains. These studies of nonferrous models have been useful, but their results have been limited because the analogy with steel ingots obviously is not a close one. Model wax ingots have also been useful in pointing out important features of mold design. Gathmann4 watched the solidification of wax ingots, through a glass-walled mold, and has reported the effects of mold type on the location of the shrinkage cavities. Segregation was simulated by using a mixture of paraffin and stearine and adding a red dye that on freezing segregated preferentially to the stearine. Brearley5 also used wax models to determine .the effects of some of the principal features of mold design. Carlsson and Hultgren6 used stearic acid to show that the columnar crystals of ingots tend to slope upward progressively from the mold wall toward the center of the ingot. As with the nonferrous ingots, the wax ingots have

Jan 1, 1943

By Bruce F. Grant, Stefan F. Szasz

During 1947, a Sinclair research team was assigned to investigate thermal methods of oil recovery. The assignment was recommended by a survey of possible research approaches to increase the amount of oil that ultimately can be recovered from oil producing reservoirs. The use of heat to stimulate oil production rates by the melting of paraffin deposited in well bores can be traced back to within one or two decades of the drilling of the Drake well. The application of heat on a larger scale has been discussed by generations of oil producers. Shortly after the turn of the century, one intrepid operator is reported to have injected steam into a Pennsylvania property. After a few weeks, he apparently became discouraged and terminated his experiment. Subsequently, the literature contains references to several well-developed techniques for supplying heat to a producing well bore to melt paraffin or to reduce the viscosity of oil contained in the formation immediately around the well bore.1.?.3.4 Some early references discuss procedures to furnish heat to the reservoir,5,6 with the injection well as the heat source, thus obligating the process to maintain the entire rock mass at a temperature above that at which the desired improvement in oil recovery would occur. Another approach to reservoir heating was reported by a group of Russian technologists in 1935.7,8,9 They definitely demonstrated that combustion can occur within the porous structure of an oil-bearing sandstone. Their field experiments, however, relied less on combustion within the rock than on heat furnished by combustion of oil supplied to the injection well bore. Ignition of the air-oil mixtures in the well bore was found very difficult, and the field tests were carried on for only short periods of time. Publication of the Russian work spurred at least one independent operator in this country to try firing an air-gas injection well, on for only short periods of time. Publication of the Russian work spurred at least one independent operator in this country to try firing an air-gas injection well. The Brundred Oil Corp. reportedly obtained combustion in the sand immediately around the injection well bore, but the experiment was abandoned because of interference with normal production schedules. Injection capacity of the experimental well was greatly reduced by firing. The well was reshot and pieces of sand showing partial fusing of the quartz matrix were recovered. To the authors' knowledge no other field experiments utilizing combustion techniques for formation heating were undertaken prior to 1948, although the patent literature evidences continued interest in formation heating."'," CONCEPT OF COMBUSTION-SUPPORTED HEAT WAVE The references cited were in agreement that heat applied to a reservoir would increase recovery, but there

Jan 1, 1955

By J. L. Thompson

There are two basic forms of the LPG-slug process: the gas driven and the water driven. The pressure required for miscibility between gas and LPG prohibits the use of the gas-driven LPG process in shallow reservoirs. The water-driven LPG slug process normally exhibits good sweep efficiency. However, displacement of the LPG by water is poor. An improvement in this process appears possible by injecting a slug of carbon dioxide between the LPG slug and the water drive. Laboratory experiments were conducted in homogeneous linear systems to determine the effect of pressure on the various displacement zones. In the carbon dioxide-LPG displacement zone, the effect of pressure on the displacement efficiency is negligible above the miscibility pressure. However, the displacement efficiency decreases linearly with decreasing pressure below the miscibility pressure. With water displacing carbon dioxide, it was found that the recovery of carbon dioxide after water breakthrough can be predicted from its solubility in water. A displacement test was conducted with LPG and carbon dioxide slugs large enough to avoid interference between the oil-LPG, LPG - carbon dioxide and carbon dioxide - water displacement zones. Under these conditions, essentially complete oil and LPG recovery was obtained. However, a substantial amount of carbon dioxide was left in the core at water breakthrough. INTRODUCTION It has been shown in homogeneous linear systems that essentially complete oil recovery can be obtained by displacement with a miscible fluid such as LPG. Economic considerations dictate that the valuable LPG also be recovered. Methods proposed for recovering the LPG include (1) displacement with natural gas at a pressure high enough to make the two fluids miscible1 (the disadvantage of this method is that the required pressure of about 1,500 psi is too high for shallow reservoirs) and (2) displacement of the LPG with water2 (principal disadvantage is that a large amount of LPG remains in the formation because of poor displacement efficiency). This paper treats an improvement in the water-driven LPG slug process3,4 where carbon dioxide is injected between the LPG and water. Carbon dioxide is completely or at least partially miscible with propane and soluble in water; thus, displacement efficiency is improved at both ends of the carbon dioxide slug. To minimize effects of other variables, all experiments were conducted in linear core systems. GENERAL PROCESS DESCRIPTION The displacements of propane by carbon dioxide and carbon dioxide by water are considered separately, assuming enough of each is injected to prevent mutual interference. Displacement descriptions are confined only to the part of the pore volume containing mobile fluids unless otherwise specified. The schematic representation is given in Fig. 1. Starting at the producing well, a zone containing only oil is followed by a zone containing a single-phase mixture of propane and oil. The concentration of propane increases in the direction of the injection well and ultimately grades to pure propane. Then follows a zone containing a mixture of propane and carbon dioxide in continuously varying proportions until 100 percent carbon dioxide is reached. In this zone, the concentration of carbon dioxide in the immobile water phase also varies from zero to full saturation. Whether the displacement of propane by carbon dioxide is of complete or partial miscibility depends on pressure and temperature (Fig. 2). If the horizontal line representing the prevailing pressure intercepts the boundary curves of the phase envelopes for the prevailing temperature (i.e., if the pressure is lower than the critical

By M. H. Shumate

Rope-type haulage has had many applications in the mining and allied industries. Records have indicated favorable results both from a standpoint of efficiency and investment. The Truax-Traer Coal Co. has used some variations of rope haulage at their mines and preparation plants. They have built a system which solves their particular problems, and have an investment which has indicated an annual savings in operating costs. Rope haulage, as applied to the mining industry, goes back many years for both underground and surface mining, or a combination of both. The Truax-Traer Coal Co. has used gravity retarding hoists as well as several variations of rope haulage, including electrical and combinations of both, but each was limited in its use and application by natural conditions and economies of the operation. Several systems of rope haulage equipment are offered by manufacturers today for handling railroad car movement on a limited or continuous basis. The portal and railroad loading facilities of Truax-Traer Coal Co.'s Burning Star Slope mine, located in Jackson County, Ill., were moved in 1960. The old location was abondoned, eliminating 3% miles of underground track haulage. The mine was converted to an all-belt system, and coal is loaded at a new raw coal plant and shipped by railroad cars to a central cleaning plant. The company wanted to operate the surface facilities as efficiently as possible, employing a minimum number of workers, using the latest type railroad car movers. The existing rope haulage facilities at several locations throughout the country were examined and considered for the Slope mine location. The application of each appeared favorable but lacked flexibility, and it was difficult to justify the capital investment. The company decided to investigate the possibility of building a system that would apply to their problem, and have an investment that could be amortized in a relatively short period. SPECIFICATIONS They employed the services of Allen and Garcia Co. of Chicago, Ill. Through combined efforts, a railroad car rope system was designed to specifications as shown in Fig. 1. The Falk Corp. of Milwaukee, Wis. built the hoist to the specifications as shown in Fig. 2. It has an all welded base and pedestals. The all welded drum is not grooved. A single helical gear was used in lieu of herring bone type. A Falk speed reducer, Unit 90Y3-A, is driven by a 25-hp 1800-rpm, 440-V ac type 'C' (high starting torque) drip-proof, Frame 324-U motor. The speed reducer shaft is equipped with a solenoid operated ac spring set shoe brake, operating on a 7-in. diam. brake wheel. The dolly car, shown in Fig. 3, was field constructed, using the trucks and frame of a railroad tank car. Truax-Traer did not alter the frame but added plates and anchors for hoist ropes and frames for 8.5 tons of concrete to be used as ballast on the car. The limit switch operating shoe was also installed and the car coupler latch mechanism overhauled. The hoist rope selected was 1% in. in diam., 6x37 improved plow steel extra flexible, right lay, regular lay, with independent wire rope core, and preformed. Wedge sockets were used to connect rope to the dolly car as shown in Fig. 4. The system employs two 30-in. and three 16-in. diam. sheaves. All are bronze bushed and equipped with grease fittings. Larger sheaves are used for directional change of hoist rope and the smaller ones as snub sheaves to correct fleet angle of rope as it approaches the hoist drum. The Trench lay cable, buried between the two tracks, is used for electrical distribution and controls between hoists and operator's cab. Foundations for the system required 187 cu yards of reinforced concrete using approximately 60 cu yd each at three locations. Four hoists are employed in the system, two for each track. A pair is interconnected electrically and when one operates, moving the cars, the tail hoist idles with brake released. The process is repeated for the reverse direction. A limit switch, mounted in the track near each end of the system, is tripped by the dolly car as it approaches the hoist. The limit switch controls movement in one direction only, protecting the dolly car and establishing positive con-

Jan 1, 1962

By Jerome F. Kuzmick

The use of iron powder during the postwar conversion period has been increasing with great rapidity. This is particularly true in regard to the manufacture of molded mechanical parts such as bushings, gears, cams, small wheels, and the like. Many manufacturers have found it possible to replace machined cast iron and carbon steel with molded iron powder parts, and thereby can not only effect a savings in cost, but can produce a better product as well. As the field of application for iron powder parts widens, greater demands are made upon the powder supplier concerning quality and uniformity characteristics. The following are some of the most important properties parts fabricators desire in the iron powder they use: 1. The powder should have high compressibility so that good density can be obtained without the use of excessive pressures. At the same time, it should show low die wear so that a large number of pieces can be produced from the die. This means that the powder must be of high purity and good softness or plasticity. 2. The powder should produce compacts of high green strength, so that unsintered parts can be handled without breakage or fraying of the edges. 3. The sintering properties should be good so that satisfactory strength is obtained in the sintered piece. 4. Compacts made from the powder should show small but, above all, uniform dimensional changes during the sintering operation so that accurate parts can be produced, and warping and other such bad effects eliminated. 5. The powder should have satisfactory flow properties for automatic molding. 6. It is very important that the powder be uniform in sieve analysis, compressibility, flow, purity, and other qualities, from container to container in any given lot and from shipment to shipment. 7. Price—The fabricators desire all these good properties, but in many instances still do not wish to pay a premium price. There has been considerable discussion as to the importance of price of the powder in relation to the cost of the finished product. It is true that in cases where certain special properties only procured by powder metallurgy are required, price is not a criterion. On the other hand, there have been a number of applications recently made which would not be commercially practical with a powder which commands a premium in price. Iron powder parts are compressed in automatic presses to definite size, shape, and density. The powder is compressed to a density figure dependent upon the function the part is to perform, as well as upon such important considerations as press capacity and die wear. Such parts can be roughly broken down into the following density ranges:

Jan 1, 1949

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

In the past most of the research in pelletizing has as its aim the production of a physically strong pellet. Now that this problem is solved, more attention is being paid to uniformity in grade and chemical composition. Consideration has been given in recent years to a study of additives which will make pellets partially or fully fluxed. Blast furnace tests show fluxed pellets to have advantages over both fluxed sinter and acid pellets. Lower slag volumes are used more frequently in the blast furnace and the uniformity of the charge, both physically and chemically, is becoming increasingly important. A considerable improvement can be secured by having all of the flux uniformly distributed through the pellets in a calcined state. A fluxed pellet, therefore, should be a superior product. The use of an ore burden that contains an appropriate quantity of fluxing materials is not new to the blast furnace industry. For years the Minette ores of France and Germany, the Clinton ores of the Birmingham, Ala., areas, as well as others, which are low in iron but contain calcium carbonate in sufficient quantities to give them self-fluxing properties, have proven economical. The adaption of the sintering process to the preparation of ore burdens provided a means for artifically associating the fluxstone with the iron ore prior to charging to the blast furnace. In 1944 Torpl discussed the effects of using lime in sinter made in Sweden on the sinter's metallurgical performance in a blast furnace. Hessle2 reported in 1945 on the advantages of using lime in sinter to increase the sintering plants' capacity and reduce fuel requirements. Robinson3 discussed the use of lime in Swedish sintering practice at the 1950 Blast Furnace, Coke Oven, and Raw Materials meeting. One of the suggested advantages was the combining of lime with silica to prevent the formation of a fayalite slag, which is difficult to reduce in the blast furnace. Nilson4 at the same meeting commented briefly on experimental work that had just started in the U. S. on the use of lime in sinter. The literature tends to indicate that most of this early work was directed towards improvement in sinter physical quality, and the fact that the feed to the blast furnace was partially fluxed was incidental. It was not long, however, before blast furnace advantages were being claimed. The matter was forcibly called to the attention of North American operators by reports of remarkable production records established by the Russians using fluxed sinter. The leading step was taken on this continent by the Steel Company of Canada in 1957; McMahon5 reported on the marked improvement in performance of an 18-ft blast furnace using fluxed sinter at its Hamilton works. Other North American operators quickly followed theStelco lead.

Jan 1, 1963

By Robert E. Cuthbertson

IT is the purpose of this paper to describe in detail the laboratory development and mill application of an unusual combination of flotation reagents employed in the concentrator of the Climax Molybdenum Co., on the Continental Divide, near Leadville, Lake County, Colorado. This development originated in an ore-dressing research laboratory maintained by Climax at the experimental plant of the Colorado School of Mines, which is staffed by men directly employed by the Climax Molybdenum Co. Mill-scale testing of laboratory developments was supervised by a representative from the testing laboratory, working in close cooperation with the operating staff at the mill. General milling practice at Climax is ably described in a paper by E. J. Duggan,1 mill superintendent. Other aspects of the Climax project have been described in papers by W. J. Coulter,2 by Butler, Vanderwilt and Henderson3 by Allen Kissock,4 and by Leo H. Glanville.5 Consequently, this paper will be confined to the metallurgical aspects of recent reagent developments, avoiding, as much as possible, repetition of material covered in these earlier publications. BRIEF HISTORY OF REAGENT PRACTICE AT CLIMAX Prior to the year 1937, the only reagents employed at Climax for froth production and collecting action in the flotation of molybdenite were steam-distilled or destructively distilled pine oils. The only exceptions to this practice were brief periods of mill testing, when reagents of various types were tried on an experimental basis. None of these experimental runs was sufficiently encouraging to justify its continuation as regular practice. Sodium, cyanide has been employed since the very early days of milling at Climax as an inhibiting agent for control of pyrite and chalcopyrite. Alkaline reagents such as lime or soda ash have been used in recent years to minimize the detrimental effect of iron salts on flotation of molybdenite. The presence of these harmful salts is attributed to the decomposition of fine metallics abraded from liners and balls in the first stage of regrinding rougher concentrate. Flint pebbles are used in subsequent regrinding, since alkaline reagents are not entirely adequate to offset the inhibiting effect of iron salts as the grind becomes progressively finer and the grade of concentrate progressively higher. Climax metallurgists were familiar at an early date with the use of petroleum products such as kerosene and gas oil as promoters of flotation of molybdenite. Charles C. Oliver6 discussed the use of pine oil and kerosene as early as 1920, in connection with the milling practice at Dominion Molybdenite Co., Quebec. Never theless, the early attempts to apply this knowledge in the Climax concentrator were complete failures. In the light of recent experience, it may seem strange that the early mill tests with petroleum

Jan 1, 1944

By J. H. Lightfoot, Stuart E. Buckley

DEEP drilling has led to the development of numerous pools which yield products consisting predominantly of natural gas accompanied by high-gravity water-white or slightly straw-colored liquid. Yields of this "condensate" or "distillate," as it is commonly called, vary from traces to over a hundred barrels per million cubic feet of gas. The fact that this liquid exists in the reservoir as an integral part of the gas phase and is formed by condensation attending simultaneous reduction of pressure and temperature after its entry into the well was apparently first recognized about 1932.1 The nature of the physical phenomena involved in this condensation was clarified for the petroleum industry in 1933 by a report by Sage, Schaafsma, and Lacey2 of the results of an experimental investigation of the behavior of mixtures of methane and propane. Search of the literature has revealed that the condensation of liquid from gaseous mixtures by isothermal pressure reduction is not a new discovery. Kuenen was led by theoretical considerations to expect such a phenomenon, and in 1892 reported3 the results of experimental verification of his deductions. This was followed by a considerable amount of work on the phase relations of mixtures by Kuenen4,5,6 and by others,7,8 mostly in European universities. Since 1930 investigators in this country have reported experimental data on the properties and behavior of a number of hydrocarbon systems.9-17 It is now generally known that in the presence of natural gas the solubility in the gas phase of the heavier and normally liquid hydrocarbons increases rapidly with increasing pressure above 500 to 1000 lb. per sq. in. Thus, at pressures of 2500 lb. per sq. in. or higher a gas may contain appreciable quantities of hydrocarbons with normal boiling points as high as 600°F., which in turn may be condensed from the gas phase by the reduction of their solubility therein attending pressure reduction. The combined effects of pressure and temperature on condensation and vaporization of mixtures are most readily visualized by the study of phase diagrams. Since the construction, application, and interpretation of such diagrams have been described fully in readily available literature, 18-20 this paper will not review the theoretical aspects of this subject. While the behavior of gas-distillate systems is now clearly understood, at least in a qualitative way, most of the published work deals with the results of laboratory studies of binary systems or of synthetic mixtures of hydrocarbons, and although several systematic investigations of the effects of separator pressure and temperature on the yields of liquid product from gas-distillate wells have been made21.22 it appears that in all cases the limitations have precluded the construction of even approximately complete phase diagrams for naturally occurring systems. There has

Jan 1, 1941

By H. G. Doll

An earlier paper on the general subject of the SP log has analyzed the limitations of that log, in particular when dealing with thin permeable beds enclosed in thick highly resistive ones. Under such conditions, the SP log does not give a good definition of the permeable beds. Selective SP logging is a new method which gives an accurate determination of the permeable beds; even in highly resistive formations, except when the salinity of the mud is extremely high. It also permits a close approxi. mation of the static SP to be obtained. The method consists generally in controlling the potential of auxiliary electrodes located in the drill holes in the vicinity of the measuring electrode. In this manner. the flow of SP current along the drill hole is modified to counterbalance the effect of highly resistive strata. Several procedure; and arrangements used to record selective SP curves and static SP curves are explained. Field examples illustrating these methods are given and discussed. INTRODUCTION In an earlier paper,' the shape of the SP curves and the amplitude of the SP peaks were analyzed, considering how the circulation of the SP current is influenced by the subsurface media as a function of their geometrical configuration and their resistivities. It was shown, in particular. that the permeable beds situated between highly resistive formations are sometimes indistinctly indicated by the deflections of the SP log. It is the purpose of this paper to dircuss a new method now being developed, namely selective SP logging, whose principal feature is to enable a more accurate determination of the depths of the permeable beds present in highly resistive formations, such as occur in limestone fields. It will be shown also how an addi-tional curve called the static SP log can be derived from the selective SP log, or recorded directly, to facilitate the interpretation. Another purpose of the static SP log is to provide an approach toward the determination of the value of the static SP, where this value is not readily given by the SP log. This application. although less important at the present time than that mentioned above, nevertheless is of interest, inasmuch as, according to laboratory and field experiments conducted by several investigators, the determination of oil saturation of reservoirs from the data of the electric log implies the knowledge of the resistivity of the connate water,2,3 to which the static SP seems to be related.4,5,6,7 PRINCIPLE OF SELECTIVE SP LOGGING The method of selective SP logging of the formations traversed by a bore hole consists in recording two curves under the following conditions: The measuring device comprises one measuring electrode M and two additional electrodes G-G', connected to each other. located above and below

Jan 1, 1950

By C. H. Mathewson, H. l. Burghoff

The study of the creep of metals under conditions of prolonged loading has received the attention of many investigators for several years and almost innumerable papers have been published on the various aspects of the subject. As it appeared that much could still be learned from a study of single crystals, the present work was carried out to study the effects of temperature and conditions of loading upon the properties and deformation in tension of single crystals of alpha brass containing about 70 per cent copper and go per cent zinc. In particular, it was hoped to obtain information from tests below and above the recrys-tallization temperature of the material, so that properties such as elastic limit, yield point or critical stress, and manner of deformation might be compared for tensile tests at an ordinary loading rate and for prolonged loading. Accordingly, short-time tensile tests and creep tests were made at room temperature, 300°, 500° and 700°F. The two latter temperatures are above the lowest possible recrystallization temperature of polycrys-talline 70-30 brass. Previous Work Clarke and White1 have made creep tests of some copper-zinc alloys, including 70-30 brass, and copper-zinc-tin alloys at temperatures both below and above the recrystallization temperature of the materials considered. Hanson and Wheeler2 have studied the flow and fracture of single crystals of aluminum for short-time and prolonged tensile loading over a range of temperature extending from room temperature to 400°F., their experiments being made without consideration of the orientations of the test specimens. Extensive creep and fracture tests on single crystals of lead at room temperature have been made by Betty3 and by Baker, Betty and Moore." Results of the last-named investigation were published while the present work was in progress. Miller5 examined the elastic limit of zinc single crystals at and above room temperature by means of creep tests, while Miller and Milligan6 reported the results of tests designed to show the influence of temperature on elastic limit of single crystals of aluminum, silver and zinc. The behavior of iron crystals under static tensile loading at room temperature was reported by Gensamer and Meh17 while the present investigation was in progress. Their specimens exhibited a well-defined yield point, below which no appreciable creep could be detected. The manner of yielding proved interesting, as the shape of the creep-time curve for the iron crystals differed from the common type of crcep curves. Elongation did not begin immediately, or at least was initially very slow. The rate of elongation then increased continuously and finally decreased to zero. This S-shaped type of elongation-time

Jan 1, 1941

By H. l. Burghoff, C. H. Mathewson

The study of the creep of metals under conditions of prolonged loading has received the attention of many investigators for several years and almost innumerable papers have been published on the various aspects of the subject. As it appeared that much could still be learned from a study of single crystals, the present work was carried out to study the effects of temperature and conditions of loading upon the properties and deformation in tension of single crystals of alpha brass containing about 70 per cent copper and go per cent zinc. In particular, it was hoped to obtain information from tests below and above the recrys-tallization temperature of the material, so that properties such as elastic limit, yield point or critical stress, and manner of deformation might be compared for tensile tests at an ordinary loading rate and for prolonged loading. Accordingly, short-time tensile tests and creep tests were made at room temperature, 300°, 500° and 700°F. The two latter temperatures are above the lowest possible recrystallization temperature of polycrys-talline 70-30 brass. Previous Work Clarke and White1 have made creep tests of some copper-zinc alloys, including 70-30 brass, and copper-zinc-tin alloys at temperatures both below and above the recrystallization temperature of the materials considered. Hanson and Wheeler2 have studied the flow and fracture of single crystals of aluminum for short-time and prolonged tensile loading over a range of temperature extending from room temperature to 400°F., their experiments being made without consideration of the orientations of the test specimens. Extensive creep and fracture tests on single crystals of lead at room temperature have been made by Betty3 and by Baker, Betty and Moore." Results of the last-named investigation were published while the present work was in progress. Miller5 examined the elastic limit of zinc single crystals at and above room temperature by means of creep tests, while Miller and Milligan6 reported the results of tests designed to show the influence of temperature on elastic limit of single crystals of aluminum, silver and zinc. The behavior of iron crystals under static tensile loading at room temperature was reported by Gensamer and Meh17 while the present investigation was in progress. Their specimens exhibited a well-defined yield point, below which no appreciable creep could be detected. The manner of yielding proved interesting, as the shape of the creep-time curve for the iron crystals differed from the common type of crcep curves. Elongation did not begin immediately, or at least was initially very slow. The rate of elongation then increased continuously and finally decreased to zero. This S-shaped type of elongation-time

Jan 1, 1941

By R. P. Carreker, J. G. Leschen, J. H. Hollomon

The external appearance of a crystal which has undergone plastic flow suggests that adjacent blocks of the crystal have glided bodily past one another along the slip planes. However, the great discrepancy between the shear stresses calculated to effect such a movement and those actually observed has for many years stimulated searches for more satisfactory interpretations of the slip process. Appreciable success in these efforts has been realized by assuming the presence in the crystal of various sorts of imperfections and by considering the consequences of the presence of these flaws when stress is externally applied. The theory that has received the most attention recently—that of dislocations—postulates the occurrence of small, mobile imperfections or dislocations which move through the crystal along the slip direction, each dislocation being attended by a local shear displacement of one interatomic distance. Thus only that portion of the crystal through which the dislocation has passed may be said to have slipped. Since each dislocation produces a displacement of only one interatomic distance, an avalanche or train of many dislocations would be necessary to account for the observed displacements of several hundred or thousand interatomic distances. The salient point of the theory of dislocations is the concept that a slip band does not suddenly appear in its entirety. On the contrary, it grows progressively across the slip plane as the individual dislocations successively appear and advance in a train through the crystal. However, the concept of growth is not intrinsic only to the theory of dislocations, since atomistic mechanisms other than that postulated by the dislocation theory can quite probably also describe the growth of a slip band. For instance, a slip band might resemble a disc-like interface that appeared and then grew continuously from a small size, producing a displacement that increased with the size of the disc. Whatever the precise mechanism, the concept of growth is in itself consistent both with the observed low values of critical shear stress and with the experimental observation that slip bands frequently do not traverse the entire crystal. The likelihood that slip bands grow implies that they must first be nucleated and that the initiation of slip can therefore be analyzed in terms of the general concepts of nucleation. Indeed, this suggestion was advanced1 several years ago, but the matter does not appear to have been further pursued. Recent advances in the theory of nucleation 2,3,4 have encouraged such a treatment of the slip process. As will presently be demonstrated, this approach to the problem not only accounts successfully for the incubation periods that have been observed 5,6 to precede slip but also predicts certain transient effects in the deformation process. The existence of these transients apparently has not hitherto

Jan 1, 1949

By J. J. Arps, T. G. Roberts

Since the introduction of the relative permeability concept in the middle thirties1,2 various investigators have shown3,10,11,12,15 how the basic equations for the flow of oil and gas through porous media can he utilized to compute the recovery from depletion type or solution gas drive type reservoirs under certain conditions, when the necessary physical data pertaining to the reservoir rock and its reservoir fluids are known. In the study by Muskat and Taylor" in 1945, the effects of viscosity, gas solubility, shrinkage, and the permeability-saturation characteristics of the producing formation on the production histories and the recovery of gas drive reservoirs were analyzed. Each parameter was varied a limited number of times, while keeping the others constant. The work was not carried to the point where the data could be used directly to estimate the primary recovery in those cases where certain rock and fluid characteristics were known or could be assumed. Since the publication of this classic study, the work by Beal in 194616 and Standing in 1952'" has established general correlations of oil viscosity and shrinkage with gas solubility and oil gravity. In addition. a considerable number of relative permeability relationships for different types of reservoir rocks has been published2,5,13,17,19,20. Also, the burden of the numerical work required in the solutions of the differential equation has. during the last few years, been greatly reduced with the availability of modern electronic computing facilities. The purpose of this paper is therefore to present the results of a large number of such recovery computations covering the normal range of variation of the main parameters such as the type of rock, the API gravity of the oil, and the amount of gas in solution. As is to be expected, the ultimate recovery is found to increase with the oil gravity. except for the higher solution gas-oil ratios. Within the normal range of solubilities, the ultimate recovery generally appears to decrease with the amount of gas in solution for the higher oil gravities, and to show a slight increase for the lower oil gravities. Intermediate oil gravities seem to fall between the two trends. The type of reservoir rock, as identified by its relative permeability relationship, appears to have a very pronounced effect on the ultimate recovery. In general, sands and sandstones show higher recoveries than limestones and dolomites, although certain intergranular limestones seem to show a higher theoretical recovery than unconsolidated sand. The recovery from sands and sandstones generally decreases with increasing cementation and consolidation, while the recoveries from limestones and dolomites are highest for the intergranular type and lowest for the fracture type porosity.

Jan 1, 1956

By H. S. Rankin, E. C. Houston

OLIVINE is considered a valuable potential source of metallic magnesium in the chloride electrolytic process. Treatment of olivine with hydrochloric acid can be carried out under conditions that prevent the formation of gelatinous silicic acid, which would inhibit the reaction by forming a covering around the ore particles. It is our hypothesis that the formation of gelatinous silicic acid is avoided by the dehydrating action of the magnesium chloride, which takes up water to form a series of hydrates and leaves the silicic acid in granular condition. Leaching serves to separate the magnesium chloride from the silicic acid and unattacked ore, which can be treated with fresh acid in successive steps until extraction is essentially complete. The leach solution can be purified by the addition of caustic magnesia and the precipitated impurities removed by decantation or filtration. The resulting magnesium chloride contains: Fe, less than 0.001 per cent; Mn, 0.012 per cent; Ni, none. Chlorination[f] of olivine has two major defects: (1) a large part of the chlorine goes to form silicon and iron chlorides, (2) the anhydrous magnesium chloride is held by absorption in the finely divided silica. SUPPLY It is well known that olivine, a silicate of magnesium and iron, is present in large amounts in several localities in the United States. The largest deposits occur in the southeast and on the Pacific Coast.1 The southeastern deposits were surveyed by Lewis2 in 1896 and by Hunter3 in the period 1933-1940. It is estimated that high-grade olivine, conveniently located with regard to transportation and power, is present in excess of 230 million tons above local drainage level in western North Carolina and north Georgia. PREVIOUS TECHNICAL WORK In the past few years, olivine has attracted considerable attention in the refractory field. In the chemical processing industry, however, it has long been thought axiomatic that the cost of processing silicates is an economic barrier to their utilization, especially where more reactive minerals, such as carbonates, oxides or salts, are available. This attitude is not entirely justified in connection with olivine. Unlike most silicates, olivine is readily attacked by acids, chlorine and other reagents without resorting to fusion to break down the silicate structure. Olivine has been suggested as a raw material for making epsom salt by roasting with pyrites.4 Other processes include acid treatment5 and digestion with calcium chloride.6 Recently a small plant was built near Webster, N. C., for making epsom salt from olivine by treatment with sulphuric acid. This plant is now in commercial operation, producing approximately two tons per day. Olivine is also receiving attention from the fertilizer industry as an inexpensive source of soluble magnesium.

Jan 1, 1942

By R. T. DeHoff

A new approach to the measurement of the size distribution of particulate structures imbedded in opaque bodies is developed. The method is based upon the assumption of a general two-parameter distribution curve, and the estimation of these two parameters from three well-known counting measurements made upon metallogvaphic sections. The total number of particles in the system is also a product of the analysis. Application of the method with the assumption of the logarithmiconorma1 disfribution function is developed in detail. A complete description of the geometry of a particulate structure requires the determination of the size distribution of particles. The problem of estimating the size distribution of particles of a particular phase in a multiphase system, or the grain-size distribution in a homogeneous system, has been approached by many investigators.'-'0 All of the solutions proposed by these investigators share the following characteristics. a) A minimum of several hundred particle sections in the microstructure must be examined, and some characteristic dimension recorded, such as area,3'5 intercept length,6"9 or diameter.1'2'4'10 b) The resulting data must undergo a series of fairly complex calculations to generate the empirical histogram which describes the size distribution in three dimensions. c) In order to manipulate the result, the histogram must be fitted to some assumed mathematical formula, using the attendant statistical procedures. d) With two notable exceptions,8,10 the particles must be spherical. The measurements and calculations involved are in general very tedious and time-consuming, with the logical result that much effort has been expended in the development of equipment which will perform these tasks automatically and semiautomati-cally.9,11-15 considerable success has been achieved in this area, but the equipment is in general expensive, and usually places stringent requirements On the quality of microstructure which can be reliably analyzed. In laboratories which do not possess such equip- ment, the analysis of geometry is usually limited to measuring total properties of the microstructures, such as volume fraction and interfacial area, because the measurements required are much simpler to make. The determination of size distributions rarely is undertaken. The development which is presented in this paper permits the estimation of size distributions of three-dimensional structures from the same simple counting measurements which are required to determine the surface area and volume fraction of the particulate structure, and one other counting measurement. The basic approach that is used is to assume a general mathematical form for the distribution, which is described by two parameters (as the normal distribution is described by assigning values to the mean and the standard deviation), and then estimate these two parameters from the results of the counting measurements. The introduction of a third counting measurement also permits the evaluation of the number of particles per unit volume, Nv.

Jan 1, 1965

By Frank Foote, E. R. Jette

In recent years the constitution of the high-silver aluminum-silver alloys has been extensively investigated. Hansenl has reviewed the literature to 1935. More recently, Obinata and Hagiya,2 Hofmann and Volk,3 Taziri4 and Tishchenko5 have confirmed the general features of the phase diagram in the region around 25 atomic per cent aluminum. In this paper we present the results of high-precision measurements of lattice constants of the silver-rich alpha solid solution in the homogeneous range and the neighboring two-phase regions. These results are used to establish the nature of the solid solution, the identity of directly measured densities with those calculated from lattice constants and the homogeneity limits of the alpha solid solution with respect to three different neighboring phases. A study of the earlier investigations indicated that the last two subjects in particular required new and accurate data. Experimental Procedure Preparation of the Alloys.—The alloys were made from high-purity silver and aluminum. The silver was "Proof Silver," 99.999 per cent pure, supplied by the U. S. Metals Refining Co. The aluminum was 99.97 per cent pure (contained Si, 0.009 per cent; Fe, 0.0016 per cent; Cu, 0.004 per cent) and was supplied by the Aluminum Company of America. The lattice constants of these two materials have been reported by Jette and Foote.6 Weighed amounts of the two metals were placed in alundum crucibles and melted in vacuo in a high-frequency induction furnace. The melts were allowed to cool in the crucible, the ingots thus obtained weighed about 10 grams. These ingots were then filed clean, hamered, again cleaned and given a homogenizing anneal in vacuo of from 6 to 15 days at temperatures ranging from 500" to 695°C. The ingots were air-cooled from the annealing temperature. Lattice-constant Measurements.—Carefully prepared filings for X-ray analysis were sealed into evacuated quartz or Pyrex tubes and annealed for various periods of time at suitable temperatures. The furnaces used were vertical, rapid-quenching furnaces, the samples being quenched by crushing the sample tube under water by means of a heavy plunger. The general X-ray technique has been previously described6 The cameras were of the symmetrical, back-reflection, focussing type. Ka, radiation from a cobait-nickel alloy target was used. The wave-length values were taken from the second edition of Siegbaum's book.7 A correction for the index of refraction was applied and the lattice constants were calculated by the method of Cohen.8, 6 The lattice constants were calculated to a common temperature of 25°C., using the value of the linear expansion coefficient of pure silver as 18.9 X 10-6. Presumably the expansion coefficient for

Jan 1, 1941

By Frank Foote, E. R. Jette

In recent years the constitution of the high-silver aluminum-silver alloys has been extensively investigated. Hansenl has reviewed the literature to 1935. More recently, Obinata and Hagiya,2 Hofmann and Volk,3 Taziri4 and Tishchenko5 have confirmed the general features of the phase diagram in the region around 25 atomic per cent aluminum. In this paper we present the results of high-precision measurements of lattice constants of the silver-rich alpha solid solution in the homogeneous range and the neighboring two-phase regions. These results are used to establish the nature of the solid solution, the identity of directly measured densities with those calculated from lattice constants and the homogeneity limits of the alpha solid solution with respect to three different neighboring phases. A study of the earlier investigations indicated that the last two subjects in particular required new and accurate data. Experimental Procedure Preparation of the Alloys.—The alloys were made from high-purity silver and aluminum. The silver was "Proof Silver," 99.999 per cent pure, supplied by the U. S. Metals Refining Co. The aluminum was 99.97 per cent pure (contained Si, 0.009 per cent; Fe, 0.0016 per cent; Cu, 0.004 per cent) and was supplied by the Aluminum Company of America. The lattice constants of these two materials have been reported by Jette and Foote.6 Weighed amounts of the two metals were placed in alundum crucibles and melted in vacuo in a high-frequency induction furnace. The melts were allowed to cool in the crucible, the ingots thus obtained weighed about 10 grams. These ingots were then filed clean, hamered, again cleaned and given a homogenizing anneal in vacuo of from 6 to 15 days at temperatures ranging from 500" to 695°C. The ingots were air-cooled from the annealing temperature. Lattice-constant Measurements.—Carefully prepared filings for X-ray analysis were sealed into evacuated quartz or Pyrex tubes and annealed for various periods of time at suitable temperatures. The furnaces used were vertical, rapid-quenching furnaces, the samples being quenched by crushing the sample tube under water by means of a heavy plunger. The general X-ray technique has been previously described6 The cameras were of the symmetrical, back-reflection, focussing type. Ka, radiation from a cobait-nickel alloy target was used. The wave-length values were taken from the second edition of Siegbaum's book.7 A correction for the index of refraction was applied and the lattice constants were calculated by the method of Cohen.8, 6 The lattice constants were calculated to a common temperature of 25°C., using the value of the linear expansion coefficient of pure silver as 18.9 X 10-6. Presumably the expansion coefficient for

Jan 1, 1941