Search Documents

By B. M. Larsen, T. E. Brower

Introduction and Summary By "thermochemical factors" we refer to those variables which affect the net heat which must be put into the bath in order to make a heat of steel from any given set of charge materials. This is admittedly only one phase of the production rate problem. The whole problem includes also consideration of rate of charging, flame radiation intensity, rate of optimum fuel input obtainable without undue damage to the furnace structure and any variations in conditions such as stirring, slag volume or viscosity which affect the rate at which heat can flow down and away from those exposed surfaces where the heat is first received from the flame. Because a given type of charge in a shop is often considered as being nearly constant in both physical and chemical characteristics from one heat to another, and because such a state of affairs may be thought of as resulting in a reasonably constant net heat requirement, this requirement is usually neglected as an invariable, inevitable matter, about which nothing can be done. With normally variable charge, and variable percentages of limestone and cold pig, however, the net heat requirement can be subject to very appreciable change; it may also be affected by such things as the currently popular procedure of blowing oxygen into the bath. To bring the general problem of production rate into better perspective, therefore, it seems worthwhile to try to evaluate the net bath heat requirement and the amount by which it may change through variation in different factors. Because our calculated values of net heat are admittedly uncertain, we have tried to check them in part by statistical data on actual production rates over rather large groups of commercial heats. The results of calculation of net heat requirements in a wide range of actual commercial practices may first be summarized briefly. We find a wide range between the extremes of different practices, as would be expected, with duplex practice (essentially blown metal plus hot metal) having essentially a zero net heat requirement, an all-cold charge practice somewhat over I million Btu per ton of steel and a high hot metal practice about 0.75 million Btu per ton. Over the commercial range of scrap plus hot metal practice, increasing the percentage of hot metal from 40 to 78 pct, with other factors nearly constant, decreased the net heat by only some 5-10 pct. The net heat is increased by about 1.2 pct for each I pct of the metallic charge present as cold pig. Calculated values of oxygen supplied by air varied from about 25 up to 60 lb per ton of steel, and in a 60 pct hot metal practice, an increase from 32 to 52 Ib oxygen from air decreased the calculated net heat from 0.88 to 0.74 million Btu per ton. Use of pure cold oxygen to substitute for about one half of the total charge ore (about 28 Ib oxygen replacing 145 Ib ore per ton of steel) decreased the

Jan 1, 1949

By L. G. Austin, R. R. Klimpel

This article demonstrates that the Gilvarry and Klimpel-Austin equations for the random fracture of solids are incorrect by deriving intuitively correct expressions for simple cases and showing that the foregoing equations do not reduce to right answers. It is the purpose of this article to point out serious errors in some existing treatments of the random fracture of solids. Gilvarry ' gives the equation where B(y,x) is the cumulative fraction by weight of particles which fall below size y when particles of size x are broken. The constants i, j, k contain shape factors and densities of flaws leading to propagating fracture surfaces. The authors believe this equation to be incorrect. Klimpel and usttin' give where r~ is the number of fracture planes originating from edge flaws (per L where L is the edge length of the original particle), rs is the number of fracture planes originating from flaws on the particle surface (per S where S is the surface of the original particle) and rv is the number of fracture planes originating from flaws within the particle volume. This equation is also incorrect. The failures of these equations will be demonstrated by deriving intuitively correct expressions for simple cases and showing that the Eqs. 1 and 2 do not reduce to the correct answer. In this process, the flaws in statistical reasoning inherent in the derivations of Eqs. 1 and 2 become apparent. THE KLIMPEL-AUSTIN EQUATION Eq. 2 was derived by considering a set number of fracture planes occurring spatially at random within a given particle. This case will be treated here in its simplest form: a line with 1, 2, 3, etc., fractures occurring at random. This is illustrated in Fig. 1, with the original length of the line as Vo. The breakage of a long, thin, brittle fiber is a corresponding physical case, with the volume of a fragment proportional to its length. Assuming independence of the occurrence of the fractures, the probability of any one fracture occurring in length dV is dV/V0. The probability of the first fracture occurring at a length V to V + dV is dV/Vo. For the case of only one fracture per particle, formation of a number-size distribution of the left-

Jan 1, 1969

By Robert T. Howard, Morris Cohen

IT has long been realized among metallurgists that a fast, reliable method for the quantitative determination of the percentage of microconstituents in an alloy would be of great benefit in studies of equilibrium and transformation in the solid state. For example, Polushkin1 has shown that the compositions of two coexisting phases in a a binary system at a given temperature may be calculated very simply with the aid of two alloys lying in the two-phase field if the relative amounts of the two phases in each alloy can be determined. Recently, Grange and Stewart2 have traced the course of the austenite-martensite reaction in a series of commercial steels by making visual estimates of the percentage of martensite formed as a function of cooling temperature. The correlation of mechanical properties with structure, a subject of wide-spread current interest, is likewise dependent upon quantitative microanalysis.3 Yet, there are very few investigations described in the metallurgical literature, wherein methods of quantitative microscopy are employed. Usually, the relative amounts of the microconstituents are estimated in a qualitative or semiquantitative way. The authors were faced with this problem some time ago in studying the kinetics of austenite decomposition. Several aspects of, this research could not be treated satisfactorily by other quantitative tools, such as specific volume,4 magnetic,5 dilatometric,6 electrical resistance7 or x-ray measurements.8 It became necessary to find an impersonal quantitative method that could be applied to microstructures. Fortunately, it was noted that geologists and petrographers had coped with quantitative microscopy to a considerable degree in their attempts to evaluate the mineral contents of rocks. A number of excellent articles were found on this subject, and since they appear to be unknown generally to many metallurgists, the first part of the present paper is concerned with a review of the literature in some detail. With this survey as a background, the authors have adapted the so-called methods of point-counting and lineal analysis to metallography, as described in the second part of the paper. Austenite-martensite structures were selected for illustration not only because they are important in many ways, but because such fine intermixtures are notoriously difficult to estimate visually. LITERATURE SURVEY Perhaps the earliest work on quantitative microscopic analysis goes back to Delesse9 (1848) who proved mathemati-

Jan 1, 1947

By Jerome Alexander

The object of this paper is to show that many of the important phenomena of metals and alloys are due to the facts that, at some stage, metals and alloys, or some of their constituents, are in a colloidal state and that a portion of the metal or alloy tends to remain in this state. The so-called amorphous phase in pure metals is an isocolloid, consisting of colloidal groups of metal molecules that may be dispersed in still more finely subdivided metal; these colloidal particles are not truly amorphous, but may consist, in part, if not entirely, of ultramicroscopic crystals; as a result the expressions amorphous phase and amorphous theory might he replaced by the expressions colloidal phase and colloidal theory. Any substance is in the colloidal state when the constituent particles consist of molecular or atomic groups, whose size varies approximately from about 100 down to about 5pp, that is from just below the limit of microscopic resolvability to the dimensions commonly ascribed to the larger molecules. Colloidality involves no assumption as to the shape, internal structure, or orientation of the colloidal particles; size alone is the critical factor. A colloidal system may therefore contain crystalline groups, or amorphous groups (non-crystalline, random or haphazard clusters), or a mixture of the two. All colloids consist of at least two phases, the subdivided substance, or dispersed phase, and the substance into which this is subdivided, the dispersion medium. It is not necessary that there be any chemical difference between the dispersed phase and the dispersion medium. As molecular forces are extremely powerful, their application may produce marked changes in the physical properties of metals. It is doubtful whether metal in the interior, especially of large masses, possesses the same properties as that on or near the surface, which alone is open to inspection.

Jan 1, 1921

By A. S. Yue

The interface morphology of the Mg-32 wt pct A1 eutectic has been studied in terms of the freezing rate, the temperature gradient, and the impurity content. For the impure eutectic it has been found that for a given temperature gradient a fast freezing rate favors the formation of a cellular intwface with sub-grain strucfure. This cellular interface can be changed to a planar interface of the same substructure either by decreasing the freezing rate or by increasing the temperature gradient. For the eutectic of highest purity, as purified by zme-refining, no cellular interface was found for any growth condition and only a planar interface with subgrain structure was observed. Furthermore, a layer of liquid adhering to the interface during de-cantation freezes with shapes and sizes of the phase particles different from those in the main eutectic solid. WHEN a molten metal or a binary eutectic liquid with zero freezing range is solidified unidirec-tionally, a cellular interface is usually formed-3 This interface is schematically represented by Fig. 1. The profile of the solid-liquid interface has a corrugated shape, as shown in Fig. l(a), while the decanted interface consists of cells, as shown in Fig. l(b). The cell boundary in a frozen eutectic is distinguishable from the cell interior by changes in particle shapes, as shown in Fig. 4. The formation of a cellular interface, according to Weart and ack,' is attributed to a layer of constitutionally supercooled" liquid generated at the advancing interface by the simultaneous rejection of an impurity by the two phases of the eutectic mixture, which then permits freezing over an appreciable temperature range. This concept has been further elaborated by Tiller, who predicts that even in the absence of an impurity the rejection of solute ahead of each lamella of the eutectic may promote the formation of a cellular interface. More recently, Chilton and Winegard, and

Jan 1, 1963

By G. L. Oldright

THE development of the reverberatory furnace for smelting copper ores up to 1912 was described by E. P. Mathewson1 with details concerning the great changes in dimensions of the furnace. Hayward2 tabulated similar data, giving developments up to about 1924, in his revision of Hofman's Metallurgy of Copper. DEVELOPMENT OF PRESENT SMELTING PRACTICE Dimensions of Furnace Very great changes were made in the dimensions of the smelting hearths of the furnaces in the period from about 1800 to 1906, the length increasing from about 11 to 116 ft., and the width from 8 to 19 ft. During this time the tonnage smelted increased from about 9 to 250 tons per 24 hr., and the tons of charge smelted per ton of coal increased from 0.77 to 4.3. Dr. Mathewson3 noted no great difference in the "fuel ratio" (i. e., the amount of charge smelted per ton of coal) as the furnace at Anaconda was increased in length by stages from 85 to 116 ft. (The percentage of copper in the slag, however, was lowered from 0.42 to 0.36 per cent. The other components of the slag were not given.) Lump coal fired on grates was the fuel used during this period. The practice in operating the furnaces over such a length of time naturally varied considerably, and there were differences in composition and nature of the charge, yet it may be considered that the improvements made were due largely to increases in the size of the furnace used. Doubt-less some credit should be given to improvements in operating technique, like changes in the methods of firing the lump coal. However, the greater part of the advance was probably due to factors influencing the

Jan 1, 1928

By P. D. Gorsuch, D. L. Newhouse, Irvin R. Kramer

ALTHOUGH many methods have been suggested for the calculation of tensile strength and yield point from chemical composition, their usefulness has been limited to a particular cooling rate or section size. Further limitations have been imposed by failure to take into account many of the alloying elements that exert a considerable influence on the tensile strength or yield point. These systems, nevertheless, have filled an important need in many instances. The value of a system for the calculation of the tensile properties from the chemical composition and cooling rate is that it permits the prediction of the effect of alloying elements and heat-treatment on the mechanical, properties, so that more efficient use of alloying elements may be made. Furthermore, it aids in the choice of steel for a given application and tends to decrease the number of steels that otherwise would have to be tested. It is the purpose of this work to present a method of calculating tensile strength and yield point from the chemical composition and to suggest a method of correlating the tensile-strength and yield-point factors and cooling rate. Steelmakers have been interested for many years in the calculation of the tensile strength of hot-rolled steels. Quest and Washburn' summarize several of the attempts that have been made to devise formulas. They show the inadequacy of each of these formulas and present one of their own. It is apparent from their work that a simple additive equation of the type TS = A + BX + Cy + DZ + ? ? ? , where A, B, C, D, etc. are experimentally determined constants and x, y, z, etc., are the percentages of alloying elements present in the steel, is not adequate to analyze fully the situation encountered in the calculation of tensile strength. For example, it was found that the difference between the calculated and observed values became progressively greater as the carbon and manganese contents were increased. Therefore, the effect of manganese was given as a function of the carbon content. Grossmann,2 in his work on the hardenability of quenched steels, and Walters,3 in his method of calculation of tensile strength of normalized steels, present two cases in which multiplying factors were successfully used to express the combined effect of alloying elements. The factors in both cases were obtained from the fractional increase in hardenability or tensile strength with increase of alloy content. Yield point often is more important in design than tensile strength. For quenched and tempered steels a linear correlation exists between yield and tensile strength .4 This is not true, however, for normalized

Jan 1, 1946

By C. Kolm, E. P. Warekois, S. A. Kulin

MUCH insight has been gained into the nature of the cold-worked state of metals in recent years through the use of modern X-ray techniques. These methods have revealed the existence of stacking faults together with regions of high internal strain and have provided means of measuring the atomic perturbations in plastically deformed metals. In view of the recent increased interest in the solid state, it is desirable to extend these techniques to the study of lattice imperfections introduced into semiconductors during plastic deformation. It is of particular interest to compare the state of imperfection sustained by metallic bonding with that sustained by the covalent bonding found in semiconductors. A knowledge of the imperfections which can exist in semiconductors is important from both a theoretical and a practical point of view since they can greatly influence many of the physical properties. In order to determine the possible existence of stacking faults in covalently bonded structures, precise measurements were made of the diffracted peak positions of plastically deformed germanium, gallium antimonide, and indium antimonide. These measurements were based on the theoretical treatment of Paterson1 and are similar to those employed by Warren and warekois2 in their studies of deformed a brass. In addition, diffraction peak profiles were measured on the annealed and plastically deformed materials in order to obtain information concerning the distribution of internal strains through the use of the Fourier methods developed by Warren and Averbach.3 EXPERIMENTAL PROCEDURES AND TECHNIQUES Because of the room-temperature brittleness of the semiconductors studied, it was necessary to plastically deform the materials at elevated temperatures. The brittle-ductile transition temperature ranges of GaSb and InSb are sufficiently low to permit hot-filing operations. Therefore, high-purity, polycrystalline GaSb and InSb were filed in an argon atmosphere at 400' and 300°C, respec-

Jan 1, 1959

By F. C. Sturges

[CONTENTS PAGE ................. Introduction-Grouting in Mines. By F. C. STURGES. I Use and Technique of Pressure Grouting in the Construction Industry. By V. L. MINEAR . 3 Technique of Pressure Cementing in the Petroleum, Mining, and Construction Industries. By WY. D. OWSLEY and R. E. MOELLER. ..................... 9 An Example of Controlled Pre-grouting in Shaft Sinking. By R. H. ALLEN and J. W. GALPIN. 15 ........ Solidifying Mines and Shafts Areas by Pressure Grouting. By B. H. MOTT 17 .............. Grouting in Southeast Missouri District. By W. W. WEIGEL 20] Introduction-Grouting in Mines By definition the word "grout" means a thin mortar, or a kind of plaster or cement, and "grouting" means to fill up or finish with grout. The words "cement," "plaster" and "mortar" mean a substance that is used in a soft state which subsequently hardens. Thus, grouting is the filling of void space with a substance that hardens. Construction cements are the most common substances used, either by themselves or in mixtures, but the term grouting is applied quite correctly when other substances such as plastics and certain chemicals are used. Also, the use of the term grouting to cover the filling of voids with materials that do not actually become hard, such as the flotation tailings used in grouting in the southeast Missouri lead district, should be considered correct, as some stiffening does take place and, anyway, it is a better descriptive term than any substitute. Engineers are interested in grouting because some of the materials with which they must work contain voids, and certain conditions can be improved if these voids can be filled with something solid and permanent. Grouting is done to accomplish several purposes: I. To stop the passage of fluids and gases, 2. To cement materials together to make them stronger, and 3. To prevent consolidation of materials by filling void space with something solid as a replacement for the air and water that could be forced out under load. The construction industry uses grouting extensively for all three purposes. Grouting is used to stop water percolation under and around dams. It is used to control water flow in tunnel driving and in shaft sinking. It is used to improve foundation conditions under civil engineering structures by permanently filling void space and thereby reducing settlement, or by cementing broken rock together and increasing its supporting strength. The oil and gas industry does a lot of grouting, primarily to stop the passage of gases and fluids. The search for oil at increasingly greater depths has meant greater investment per well, and the oil industry has spent large sums on development of improved drilling methods. This

Jan 1, 1947

By Reinhardt Thiessen

Under sulfur in coal, is usually understood that form of sulfur which is combined with iron and known as pyrite. It occurs in the form of balls, lenses, nodules, continuous layers, thin sheets, or flakes, both in horizontal planes and vertical cleavage fissures. But pyrites also occur as very fine microscopic particles, or nodules, disseminated through the compact coal. This form has had but very little consideration. Finally, there is sulfur in coal in an amicroscopic form (not visible with an ordinary microscope), probably combined with the organic matter that exists in the coal. This form has had considerable attention from a scientific standpoint, but has probably not been recognized enough on the economic side. One or the other, or both, of these two latter forms may comprise the larger part of the sulfur content of coal, especially after it has been washed or otllerwise prepared for use. Pyrites in Microscopic Particles All coals that have been examined by the author contained a varying amount of sulfur in very small globules, or particles, of pyrite. These particles are seen in a thin [section as roughly rounded opaque dots, Figs. 1 to 10. When isolated, they are generally shown to be approximately spherical in shape, with a rough outer surface. They vary in diameter from a few microns to a hundred microns, the majority messuring from 25 to 40 microns; relatively few exceed the latter diameter. They are, therefore, very small objects. Their size is best appreciated by comparing the illustrations, in which they are shown. at a magnifiea tion of 100 diameters, with some known area like the period used in the ordinary printed page. The period is about 0.6 mm. in diameter, and . when magnified 100 times, will cover a circular area of about 2 1/2 in. in diameter, or all but the corners of the illustrations. The illustrations, therefore, represent an area about as large as an ordinary period, and the pyrite globules form but a small part of the total area. Very frequently a number of these particles are joined together in horizontal rows; oc-

Jan 1, 1920

By B. Trentini

In the spectacular development of pure oxygen steel-making, the process using the vertical lance converter LD, is at the present time the most widely employed. Proper control of slag composition during the steel-making process appears to be essential in achieving satisfactory blowing from both the metallic yield and metallurgical points of view. The paper illustrates the primary importance of the presence of a large quantity of metal droplets in the slag during the process. In the case of both phosphorus and hematite pig iron, it can be deduced from the phase diagrams and confirmed by experimentation that nonhomogeneous slags are one of the causes of slag overflowing during the blow. The problem is however a complex one and further physicochemical studies appear necessary. Finally, the new continuous steelmakingprocess developed by IRSID is described. PEOPLE who knew Henri Marion Howe have said that he took great pleasure in speculating on the future of metallurgical processes. It is therefore not inappropriate to devote, in his memory, some description and discussion to processes unknown to the world of his time, in particular oxygen steelmaking and continuous steelmaking. The first industrial application to steelmaking of tonnage oxygen produced by air liquefaction was made in Germany just before the war and consisted in enriching the air blown through the bottom of a basic Begsemer converter in order to melt a higher proportion of scrap and to produce steels with lower nitrogen content than is achieved with conventional practice. While this process was being developed after the war, mostly in Western Europe, steelmakers were becoming increasingly familiar with the technique of blowing pure oxygen from the top, first by means of consumable steel pipes, with or without refractory shielding, and later by water-cooled lances, designed for the purpose and affording longer life. The field was then open for the wide use of pure oxygen in steelmaking, either in existing processes such as open-hearth or electric furnace, or in new processes. These new processes can be broadly classified according to the category of furnace employed. In the case of the vertical converter taken as the first category, bottom-blowing of pure oxygen causes extremely rapid wear of the refractory tuyeres, and although various expedients have been tried to overcome this drawback (such as mixing oxygen with CO2 or H2O or using high pressure oxygen), they have had to be abandoned. The solution for vertical converters has been found in top-blowing with a vertical water-cooled lance; this is known as the LD process or basic oxygen converter process.

Jan 1, 1969

By R. M. Brick, Arthur Phillips

The normal method of preparing metallic alloys for commercial use involves the preparation of a melt containing the given components in the chosen proportions and allowing the homogeneous liquid mass to solidify in a mold of the desired form. The solidification is frequently accompanied by a segregation of the alloying elements in different parts of the casting. When the segregation is occasioned primarily by marked differences in density of the solid and liquid phases, it is termed "gravity" segregation. When the segregation conforms to a selective freezing in harmony with the teachings of the equilibrium diagram of the alloy system—i.e., the lower melting phases are concentrated in the regions of the casting last to freeze—it is often referred to as "normal" segregation. However, in many cases the lower-melting part of the system is concentrated in the parts of the casting first to freeze and the result in this case is termed "inverse" segregation. To complete the terminology of the subject, normal segregation in a single phase is usually called "coring" and the word will be used in that sense in this paper. Inverse segregation, particularly when the liquid phase is exuded or sweated out on the surface of the casting, is sometimes called "liquation." Unfortunately, some ambiguity has arisen from the use of this term and it is perhaps advisable to confine its use to the dictionary definition; namely, "The separation of two phases by heat sufficient to melt one but not the other." The gravity and normal types of segregation are both well understood and to some extent, are controllable by taking advantage of the most favorable cooling rate for a given casting condition. Inverse segregation has received considerable attention from several investigators but none of the theories offered seem to account in a convincing way for the many examples of this type. The observations made in the present work on segregation in single crystals, and in some other castings, tend to support one theory of the mechanism of inverse segregation and definitely to

Jan 1, 1937

By Christopher H. Bierbaum

The first significant fact observed in the study of bearing metals is that not a single pure homogeneous metal has given satisfactory service; all bearing metals are alloys made up of two or more phases; that is, they consist of hard and of relatively soft microscopic particles intimately mixed. The function of the hard particles, or bearing crystals, is to support the load and resist the wear when actual metallic contact exists between the bearing surfaces. The functions of the softer particles are to allow the harder particles to adjust themselves to the surface requireinents of the journal and to wear down slightly below the surface of the harder, forming slight depressions on the apparently smooth wearing surface of the bearing, in which some of the lubricant is held when the bearing surfaces are brought into contact with each other. It is this characteristic of certain alloys to form these slight depressions, and thus provide the means for retaining a lubricant, that characterizes them as true bearing metals; in fact, a bearing metal has been defined as "an alloy that is capable of retaining a lubricant upon a bearing surface."' The extent to which the lubricant can be so held determines the most valuable characteristic of an alloy as a bearing metal. An alloy which, perhaps, most characteristically represents a bearing metal is the composition of copper and tin that contains sufficient tin to produce the tin-copper eutectoid, or delta crystal. The depressions worn upon the surfaces of the softer crystals of the teeth of a motor-truck worm wheel, made of an ll-per cent. tin bronze, in many cases were from 5 to 6 microns in depth; all other conditions remaining constant, this depth of wear increases with an increase of working pressure. This copper-tin bronze contains intercrystalline shrinkage cavities, which also

Jan 1, 1923

By N. T. Cotman, C. H. Pickering, P. B. Crawford

A beat-conduction model has been developed to study the flow of fluids in a stratified oil reservoir which is being subjected to unsteady-state depletion. To simulate stratification, plates of different metals were joined together so that cross flow could occur between strata. A description of the model, plate construction and necessary instruments is included. The data indicate that stratified oil reservoirs experiencing cross flow may be treated as a single, homogeneous, producing sand having properties intermediate between those of the layers making up the system. A technique for averaging core-analysis data to arrive at the proper average value of rock permeability and porosity is presented INTRODUCTION Although oil has been produced from reservoirs for 100 years and reservoir injection processes have been undertaken for 40 years, the industry is still inadequately informed on the problem of reservoir inhomogeneities. Stratification is perhaps the best-known type of reservoir heterogeneity. Urenl discussed the possible significance of this nonuniformity in his 1927 paper on the theoretical aspects of water flooding. Since this time the problem of vertical permeability variations has been the subject of much discussion and numerous papers. Levorsen2 simply describes the origin of layered beds in his Geology of Petroleum. Some beds are field-wide and may be traced from well to well, while others apparently pinch-out and become discontinuous. In addition, the physical characteristics of a layer may vary from place to place. For these reasons, a stratified system is not easily defined. In calculations involving oil reservoirs in which permeabi1ities vary, methods presently used contain many simplifying assumptions. The reservoir frequently is considered as consisting of permeable layers, each of uniform vertical and lateral permeability and each behaving as if separated from adjacent layers by thin impermeable layers. Other assumptions frequently made in reservoir calculations are steady-state flow conditions, unit mobility ratio, linear geometry, average or homogeneous porosity, and negligible capillary-pressure and gravity effects. Muskat3 has. developed solutions to the stratification problem for mobility ratios other than unity for both linear and exponential permeability distributions. He assumes lateral uniformity and continuity of all productive strata and does not consider porosity. This study will take into account transient effects, cross flow and varying porosity, as well as the variations in permeability, by means of a heat analogy. Muskat5 has shown the similarity of the equations which describe the flow of fluids in a porous medium to the flow of heat through a solid. Landrum, et al,6 made an analogy between the flow of fluid in an unsymmetrical reservoir and the conduction of heat in a similarly shaped metal plate. This analogy is summarized briefly as follows. If fluid is produced from an oil reservoir above the bubble point, the resulting pressure distribution will be identical to the temperature which would result in a metal or heat-conducting plate if heat were similarly removed. This means that a study of heat flow in stratified thermal models will behave like fluid flow in stratified oil reservoirs. For mathematical correspondencies, set- Ref. 6. The fluid mobility k/p is proportional to the thermal conductivity, and the porosity-times-compressibility product is proportional to the density times specific heat of the thermal plate. EXPERIMENTAL EQUIPMENT AND PROCEDURE The stratified reservoir model used in this study is illustrated schematically in Fig. 1. A Leeds and Northrup Speedomax Type G temperature recorder

By John D. Sullivan, Edwin J. Rogers, Chester R. Austin

The problem of making a building unit combining the necessary physical and mechanical properties and good thermal insulation has been foremost in the minds of architects and ceramic and construction engineers for many years. This paper presents the results of studies on thermally expanding shales or clays to produce lightweight cellular products suitable for making building units. An expanded clay block suitable for building purposes should be large enough qo that substantial savings may be effected in labor costs in laying the wall. The permeability should be low and it should have sufficiently good "dry-wall" characteristics to permit exposing the exterior surface to the elements, and to permit plastering directly the inside wall surface. The thermal conductivity should be low and the mechanical properties should be adequate. Obviously, a unit possessing satisfactory qualities for constructing an - outside wall would be satisfactory for interior walls and for back-up purposes. The results of studies on bloating various shales or clays† and the properties of the expanded products are reported. In another paper1 basic factors involved in bloating of clays are discussed. Manufacturers of ceramic products, partitularly structural clay, may encounter bloating of the ware during burning, and precautions must be followed to avoid this phenomenon. About 1927 the C. F. Burgess Laboratories, Madison, Wis., while carrying on an investigation for the American Face Brick Research Corporation, conceived the idea of intentionally bloating clay while holding it in a restrained condition, with the hope of producing a unitary cellular mass. Work was carried on until about 1931, when studies were terminated because of business conditions. These studies were continued later by The Western Brick Co., Danville, Ill., which developed a process of "inwardly expansive bloating."² The major purpose of the latter investigation was to produce back-up tile to compete with concrete blocks made from Haydite or cinder aggregate. Haydite is a light-weight aggregate formed by heating certain clays or shales rapidly in a rotary kiln. While the investigations at the C. F. Burgess Laboratories or at Western Brick Co. were not carried far enough to lead to the commercial production of material for the construction of walls, particularly outside walls, they showed that certain clays could be thermally expanded and that it was possible to produce a material of low permeability with a large percentage of the total voids or cells closed. commencing in 1939, the Ozark Chemical Co. sponsored a research program at Battelle Memorial Institute for the Purpose Of determining whether it is technically feasible to make thermally expanded building units, and specifically to get answers to the following questions:

Jan 1, 1942

By Frederick L. Knouse

The south border of Espirito Santo begins about 400 km. north of Rio de Janeiro and extends along the Atlantic Coast northward some 325 km. and inland 100 to 150 km. The area under consideration, where quartz crystal of strategic grades has been mined, extends from 19º to 21º and 30º south latitude; and from 40º to 41º and 30º west longitude. This includes the central part of Espirito santo, chiefly south of the Rio Doce from the Atlantic ocean, and west across the border into Minas Gerais near the town of Aimores, in the municipalities of Aimores, Minas Gerais; Baixo Guandu, Santa Teresa, Santa Leopoldina, Colatina, Joao Neiva, Fundao and Domingo Mar-tines, Espirito Santo (Fig. I). During 1943 and the first half of 1944, this region accounted for approximately 3 to 5 per cent of the quartz crystal produced in Brazil. Shipments of crystal have been made chiefly by rail to Rio de Janeiro. This region is serviced by the E. F. Minas-Vitoria and E. F. Leopoldina to Rio de Janeiro through vitoria; and by the E. F. Minas-Vitoria and E. F. Centra] do Brasil through Bello Horizonte, Minas Gerais to Rio de Janeiro. The major deposits are accessible from the railheads by dirt roads, some being 5 to 30 km. off the road, reached by trail. In 1943 and the first half of 1944, the bulk of the production was from inter- mountain marshes and adjoining hillside alluvial placer deposits in the zone surrounding the town of Santa Teresa. Most of these deposits were formed from the erosion of pegmatite~, quartz veins and pockets in the gneiss, with minor quantities produced from miarolitic cavity fillings in the granitic rock. Early Operations Mining of quartz crystal in this region began in 1928 and has been stimulated by the market demand for military uses. Before 1936 little attention was given to it, either in Espirito Santo or eastern Minas Gerais. From 1936 to 1941 the Japanese sent agents to various points of production or potential production to acquire quartz through purchase. They bought crysta1 as small as 10 grams. Since '94' only the United States and Great Britain have received quartz from Brazil. The United States purchases crystals of 100 grams and larger for strategic purposes. The first known discoveries were made either in the municipalities of Aimores, Minas Gerais, or in Baixo Guandu, 01 Domingos Martines, Espirito Santo. Marketable quartz crysta1 was first found either in the massive quartz replacement veins of the Victor Hugo mine in the municipality of Domingo Martines, or in the large 'ores of quartz in the pegmatites near Baixo Guandu, extending into Minas Gerais. Production The production of quartz in Espirito Santo from 1936 through 1941 as recorded

Jan 1, 1948

By Arthur S. Dwight

From the latest and best literature on lead-smelting, little can be learned concerning the present state of the art of mechanical feeding in the United States. H. O. Hofman, in his Metallurgy of Lead (5th ed., 1899), briefly describes the main features of the system in use at Pueblo, Colo., and later (p. 235) says " the only successful mechanical feeding, as far as the writer is aware, is that found at the works of the Pueblo Smelting and Refining Co." H. F. Collins, in his Metallurgy of Lead and Silver (London, 1899), covers American practice pretty thoroughly; but as to mechanical charging, he says: "The German plan of taking off the gases by means of a small iron pipe suspended in the center, and the plan of charging by means of cup and cone, as in iron blast-furnaces, have both been tried, but have not found favor, chiefly on account of the difficulty of obtaining free access to the furnace-shaft for barring, etc., with such devices."' . H. W. Hixon, in his Notes on Lead and Copper Smelting (3d ed., New York, 1900), gives a description and drawing of the Hixon feeding device, as originally installed at East Helena. Evidence that this system of feeding has passed its experimental stage, and deserves more serious consideration than it has heretofore received, is furnished by two large plants—the Pueblo and the East Helena—of the American Smelting and Refining Co., where mechanical feeding has been in continuous and successful operation for a considerable period; one new plant now erecting at Salt Lake City, Utah, and one old one belonging to the same company, the El Paso works, now being rebuilt after a disastrous fire, in both of which mechanical feeding is to be a prominent feature ; one new plant of an independent concern at Torreon, Mexico, which will adopt mechanical feeding; and a number of other smaller plants, among

Jan 1, 1902

By R. D. Lee

A simplification of the method of Hurst and McCarty for conducting potentiometric model studies by the single probe method is presented along with experimentally determined invasion patterns for certain idealized flow problems. The analytical solution for one class of these problems is given. Finally, a general description is given of a newly developed instrument which permits direct mapping of flow lines and determination of transit times in potentiometric-model studies. Introduction The object of this paper is to present: I. A simplification of the method of Hurst and McCarty for conducting poten-tiometric-model studies of oil and gas reservoirs by the single probe method. 2. Results of a series of studies of certain idealized flow problems and the general conclusions to be drawn therefrom. 3. A description of a new instrument, the Chronocartograph, which greatly reduces the labor and time required for conducting potentiometric-model studies. Certain general conclusions may be drawn as results of the investigation of the idealized flow problems. They are: I. Injection and extraction areas should be separated by as great a distance as conditions permit since, in general, the recovery prior to first breakthrough tends to vary as the square of this distance. 2. Little advantage is to be gained by use of more than eight injection wells or groups of injection wells for the case of circular productive limits. 3. Elongated shapes of productive limits are best exploited by injection on the extended major axis only, with a line of extraction wells lying on the major axis. 4. The use of peripheral injection wells for elongated shapes is permissible, if necessary, but requires extension of the line of extraction wells. The exploitation of an oil or gas field is effected either by the expansion of the gas and oil, or by their displacement by another fluid. Both methods may be used simultaneously. When the displacement of the oil or gas is the controlling factor there arises the problem of mapping the progress of the boundary between the fluid in place and the displacing fluid. This problem is of particular interest in the operation of a cycling project in a gas-condensate field, where the wet gas is produced from one or more wells, commonly called "extraction wells.'' This wet gas is taken into a processing plant where the condensate is removed. The remaining "dry" gas is injected back into the field through one or more wells, called "injection wells," both to conserve the gas for future use and also to maintain the pressure in the field. In an operation of this type it is essential to anticipate the manner in which the dry gas will spread through the field, because the ultimate recovery of the wet gas depends

Jan 1, 1948

By J. Charles Miller

NATURAL carbon dioxide has recently been exploited in the United States in consequence of oil and gas developments in the Western States and the growing demand by transcontinental and transoceanic shippers for solid carbon dioxide. The discovery by drilling of commercial deposits resulted in consideration of its geographic and geologic distribution and occurrence. Its wide distribution in nature is evidenced by its occurrence in the atmosphere, hydrosphere and lithosphere. The question of origin of carbon dioxide involves consideration of theories similar to those concerning natural hydrocarbons, although available evidence favors an inorganic rather than an organic source. Areas favorable to development of commercial production appear to be those in proximity to igneous rocks or in the vicinity of decadent volcanic activity, where, it has long been known, the gas is evolved either free or dissolved in the waters of fumaroles, geysers or mud pots. Structure contour maps are presented showing the Wagon Mound anticline in New Mexico and the Farnham anticline, Utah. A well drilled on the latter supplies gas to a 20-ton plant manufacturing solid carbon dioxide at Wellington, Utah, on the Denver and Rio Grande R.R., whence it is shipped to surrounding territory and to the West Coast. Before funds are invested in a plant for the manufacture of liquid or solid carbon dioxide, whether supplied by wells or springs, an effort to ascertain the volume of gas available is advisable. The use of present methods of estimation of gas reserves with modifications to account for the quantity absorbed by any water present in the producing formation is recommended, The Farnham anticline is used as an example and cornputationa are made of the probable volume of gas originally present in the structure. No attempt was made to compute reserves in the Niland area, California, for the reason that in such areas it is believed the volume is indeterminate. INTRODUCTION Carbon dioxide, in liquid and solid form, has found a wide variety of uses other than its primary application in carbonating beverages. It is now used in more than 40 different ways, ranging from cooling or freezing to use in gas or liquid form for mechanical purposes, chemical industry, explosive, fire extinction, and tire manufacturing. Undoubtedly the chief supply of carbon dioxide is obtained from industrial plants or artificial sources and until recently natural deposits of the gas have received little consideration. Few will question the utility and perhaps dependability of artificial sources, which possess the advantage over

Jan 1, 1937

By AIME AIME

Council. * PRESIDENT OF THE COUNCIL. JAMES F. KEMP NEW YORK, N.Y. (Term expires February, 1913.) VICE-PRESIDENTS OF THE COUNCIL. S. B. CHRISTY BERKELEY, CAL. W. A. LATHROP PHILADELPHIA, PA. GARDNER F. WILLIAMS WASHINGTON, D. C. (Term expires February, 1913.) KARL EILERS NEW YORK, N. Y. WALDEMAR LINDGREN WASHINGTON, D. C. BENJAMIN B. THAYER NEW YORK, N. Y. (Term expires February, 1914.)

Mar 1, 1912