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By M. J. Humenick, K. Garwacka

A laboratory experimental research project was conducted to evaluate the use of chlorine for the oxidative destruction of residual ammonia that may remain in ground water after in-situ uranium solution mining operations. The work tested the idea of injecting high strength calcium hypochlorite solution into the mining zone to convert ammonia to nitrogen gas as a final cleanup process for ammonia removal from the ground water system. This paper details ammonia removal efficiency as a function of chlorine dose, reactant, and product material balances, and how the concept may be used as a final ground water restoration process.

Jan 1, 1985

By H. M. Day

THE constitution of the system silver-mercury has attracted the attention of many investigators during the last two decades, but since their results are for the most part in poor agreement, there is little need for a review of their individual contributions. It remained for the very careful thermal and microscopic investigation of Murphy1 in 1931 to give the constitutional diagram in its present and unquestioned form, which is shown in Fig. 1. He devised methods for taking cooling curves on alloys under high pressures and for the microscopic observation of alloys which contained liquid mercury as a structural constituent at ordinary temperatures. The compositions of the intermediate phases were con-firmed and supplemented through X-ray analyses by Preston and Stenbeck.3 According to Murphy, at 276° C. silver is able to dissolve 44 to 45 weight per cent of mercury, which may increase at lower tempera-tures to about 50 per cent. Preston concluded that the saturation boundary occurred at 46 ± 2 per cent at 100° C. From the values reported in the literature, these are the only ones that may be accepted as lying even in the right region.

Jan 1, 1938

By Walter H. Bucher

This symposium is designed to lay the basis for a general discussion of the place of geophysics in the training of geologists. As there is danger that in the ensuing debate individual interests may be given emphasis out of proportion to their place, we shall do well to view the whole field of geological inquiry in order to see the problem in true perspective. The Nature of Geological Inquiry "Basic" and "Complex" Sciences It is convenient to divide all science into two major divisions, the basic and the complex sciences. The basic sciences separate out from reality such entities as "substances" and "movements," describe their behavior in terms of arbitrary units of measurement and derive from them by progressive abstractions concepts and patterns of behavior that exist between them, so-called general "laws" and "properties" of nature. The complex sciences, on the other hand, deal, with little or no abstraction, with those objects of reality that are accessible to man in the atmosphere, the hydrosphere, the lithosphere and the biosphere. Their work comprises two types of inquiry. One is concerned with abstractions to the extent of dealing with types rather than individuals—that is, with such things as plants, animals, protoplasm; clouds, streams, gla- ciers; volcanoes and mountain ranges. It comprises the search for general properties and patterns of behavior or "laws" that characterize the objects and their reactions to each other. These properties and laws apply always, everywhere. They are independent of the stream of time. We may call the results of this sort of inquiry timeless knowledge. The other type of inquiry is concerned with the objects themselves—that is, with this animal and that plant; this river system and that mountain chain; this glacier and that valley. Like all concrete objects in nature, they are subject to change with the passage of time, especially when it is measured in years, centuries, eons. The characteristics by which we recognize them —indeed, their very existence—are dependent on their position at this point in the stream of time. This we may call time-bound kntowledge. The so-called descriptive sciences are all bound to the past of which the objects of their study are the product and through which alone their present properties call be understood. They are historical sciences. This obvious fact is easily overlooked, which leads to serious misunderstanding, as we shall see later. Dynamic Geology With this broad picture in mind, let us now examine the nature of geological inquiry, defining, for the purposes of this discussion, geology as the science of rocks. Air is not a rock; water is. Meteorology and climatology are, correspondingly, gen-

Jan 1, 1946

By Walter H. Bucher

This symposium is designed to lay the basis for a general discussion of the place of geophysics in the training of geologists. As there is danger that in the ensuing debate individual interests may be given emphasis out of proportion to their place, we shall do well to view the whole field of geological inquiry in order to see the problem in true perspective. The Nature of Geological Inquiry "Basic" and "Complex" Sciences It is convenient to divide all science into two major divisions, the basic and the complex sciences. The basic sciences separate out from reality such entities as "substances" and "movements," describe their behavior in terms of arbitrary units of measurement and derive from them by progressive abstractions concepts and patterns of behavior that exist between them, so-called general "laws" and "properties" of nature. The complex sciences, on the other hand, deal, with little or no abstraction, with those objects of reality that are accessible to man in the atmosphere, the hydrosphere, the lithosphere and the biosphere. Their work comprises two types of inquiry. One is concerned with abstractions to the extent of dealing with types rather than individuals—that is, with such things as plants, animals, protoplasm; clouds, streams, gla- ciers; volcanoes and mountain ranges. It comprises the search for general properties and patterns of behavior or "laws" that characterize the objects and their reactions to each other. These properties and laws apply always, everywhere. They are independent of the stream of time. We may call the results of this sort of inquiry timeless knowledge. The other type of inquiry is concerned with the objects themselves—that is, with this animal and that plant; this river system and that mountain chain; this glacier and that valley. Like all concrete objects in nature, they are subject to change with the passage of time, especially when it is measured in years, centuries, eons. The characteristics by which we recognize them —indeed, their very existence—are dependent on their position at this point in the stream of time. This we may call time-bound kntowledge. The so-called descriptive sciences are all bound to the past of which the objects of their study are the product and through which alone their present properties call be understood. They are historical sciences. This obvious fact is easily overlooked, which leads to serious misunderstanding, as we shall see later. Dynamic Geology With this broad picture in mind, let us now examine the nature of geological inquiry, defining, for the purposes of this discussion, geology as the science of rocks. Air is not a rock; water is. Meteorology and climatology are, correspondingly, gen-

Jan 1, 1946

By S. Leber, R. F. Hehemann

This investigation describes the kinetics of alloying in a (Cb-15 wt pct W. 5 wt pct Mo, 1 wt pct Zr) powder-metallurgy alloy. The degree of homogeneity obtained in hydrostatic ally pressed and vacuum-sintered samples is described by composition distributions resulting from analysis of X-ray dvfraction line profiles. Sintering variables and degvee of powder dispersion were evaluated. The utility of single-value parameters obtained from composition distributions is disaissed. The spatial distribution of composition, as revealed by anodically tinted metallographic sarrzples, was used to provide diffision models based on a concentric-sphere geometry. Diffusion equations developed from these models were found to be in general agreement with experimental results. The powder-metallurgy method for the production of refractory metal alloys has the ability to produce an inherently fine-grained, fabricable structure. The more general use of this method is inhibited, in part, by the presumed difficulty in obtaining homogeneity on a microscale. The degree of homogeneity therefore is an important, but usually neglected, variable in specifying the quality of a powder-metallurgy alloy. Convenient techniques for measuring the degree of homogeneity are now available,' and have been used to develop a model describing the process of alloying in a simple binary mixture.' In this investigation, the process of alloy formation has been studied in a more complex system. PROCEDURE The columbium-based F-48 mixture was prepared from the constituent powders shown in Table I. The particle sizes tabulated were provided by the vendors of the individual powders. Standard laboratory techniques utilizing a jar mill were employed for blending. The blended powders were hydro-pressed into 1-in. diam rods which were then sliced into thin discs for vacuum sintering. All samples were given a preliminary treatment at 1700°C for 2 hr. Varying degrees of homogeneity were obtained using additional treatments at higher temperatures. The degree of homogeneity obtained by a specific sintering treatment was evaluated metallographi-cally using the anodic-tinting technique described by olff,' and quantitatively by the analysis of X-ray diffraction line profiles using the X-ray diffraction technique developed by udman.' The diffraction technique is strictly valid only for binary systems. However, the relatively small difference between the lattice parameters of tungsten and molvbdenum when compared with columbium permitted the treatment of the complex composition of F-48 as a (W, Mo)-Cb pseudobinary. Calculations were weighted in accord with the W-Mo ratio in the F-48 composition. The contribution of the 1 pct Zr was ignored since it could not even be detected in the blended powder. Two factors are required to convert an X-ray line profile into a composition distribution. The variation of these factors with composition is shown in Fig. 1. Curve A was used to convert angular posi-

Jan 1, 1964

By H. Tabachnick, N. Hedley

The extraction of gold and silver from ores with alkaline cyanide solutions is well known. Cyanide solutions are also good solvents for many base metal minerals, particularly most of the copper minerals. Leaver and Woolf,1 who determined the solubilities of copper minerals in 0.10 pct sodium cyanide solution, showed that malachite, cuprite, chalcocite, and bornite are readily soluble in cyanide; least soluble are chalcopyrite and chrysocolla. The Mining Chemicals Laboratory of American Cyanamid Co. has studied the possibilities of using cyanide solutions for leaching base metals. In this article the authors present the results of their experiments with cyanide leaching to reduce the copper content of a zinc concentrate from 0.050 pct to the desired specification of less than 0.02 pct. Zinc Ore Sample: The sample of commercial zinc ore used in this investigation to produce zinc concentrates was ball mill feed ranging from 1/2 in. to fines. The ore was crushed to —10 mesh and riffled into 600-g charges for zinc flotation. Analysis revealed 4.54 pct Zn and 0.005 pct Cu. Examined microscopically, the ore consisted essentially of cream-colored sphalerite and carbonate gangue. It contained a small amount of pyrite, partly tarnished. The only copper mineral identified was chalcopyrite, mostly smaller than 20µ, some of which occurred as attachments on sphalerite. Flotation Procedure: Batches of zinc concentrates were made as required according to the following general procedure. A 600-g charge of —10 mesh ore was ground for 4 min at 60 pct solids in a laboratory steel rod mill. Screen sizing showed it to be all —35 mesh with 42 pct —200 mesh. The pulp was transferred to a Fagergren laboratory flotation machine, diluted to 25 pct solids and conditioned for 5 min with 0.6 lb per ton CuSO4, . -5H2O. It was then conditioned with 0.10 lb per ton Sodium Aerofloat promoter and floated for 5 min with pine oil as frother and creosote as froth stiff-ener. The pH during flotation was 8.5. A typical analysis of zinc concentrate subjected to leaching is 44.41 pct Zn and 0.051 pct Cu. The ratio of concentration was close to 10 to 1. Leaching Procedure: Aero Brand cyanide, technical calcium cyanide analyzing 49.5 pet NaCN equivalent, was used for all cyanide leaching tests. For each test three rougher concentrates floated as described were combined (total weight close to 180 g) and the water content adjusted to 150 ml. The percent solids in the pulp was thus 55. After a weighed amount of cyanide flakes had been added, the pulp was agitated on rolls for a given period, then filtered and washed. Filtrate and washed concentrate were assayed for copper content. The procedure for ammonia leaching was similar to the cyanide process. A series of tests was run in which the effects of ammonia as a solvent for copper in the zinc rougher concentrate were investigated. In each test 180 g of zinc rougher concentrate was leached with 150 ml of ammonia solution. Various strengths of ammonia and times of leaching were investigated. The results are shown in Table I. It is apparent that ammonia was a poor solvent for copper in the zinc concentrate; 60 min of agitation with a relatively strong NH:, solution extracted only 2 pct of the copper. CYANIDE LEACHING TESTS Effect of Solution Strength: The solvent effects of 0.125, 0.187, and 0.250 pct NaCN equivalent solutions were compared for leaching periods of 15 min. Residue and filtrate were assayed for copper content. The copper content of the filtrate plus wash was calculated back to the original volume of cyanide solution (150 ml). The effects of cyanide strength are given in Table II, It will be noted that 15 min leaching with 0.25 pct NaCN equivalent solution extracted 74.6 pct of the copper in the zinc concentrate. The leached product assayed 0.013 pct Cu, appreciably below the required specification of 0.020 pct. Effect of Leaching Time: Portions of zinc concentrate were leached with 0.25 pct NaCN equivalent

Jan 1, 1961

By F. Forward, H. Veltman, A. Vizsolyi

Activities of oxides in the ternary FeO-MnO-SiO system are calculated from data on the binaries, using the Gibbs -Schuhmann method. These activity data are used, together with thermodynamic relations, to calculate the contents of oxygen, silicon, and manganese in liquid iron, and the composition of the corresponding oxide phases in equilibrium with it. Excellent agreement was found between calculated and experimental metal compositions, indicating that thermodynamic methods, such as those presented, can supply useful data on slag-metal equilibria, and are therefore capable of wider application. When molten steel containing oxygen is treated with a deoxidizer, the product of the reaction is composed of the oxides of the deoxidizing elements together with more or less iron oxide. This assemblage of oxides is presumably very close to equilibrium with the melt since it is formed directly from elements dissolved in it. Therefore, it is likely that metal analyses corresponding to a given oxide phase composition are calculable with considerable precision where sufficient information is available on activities in both phases. The present study was made to test this hypothesis in the case of deoxidation by silicon and manganese. Here experimental data on the relationship among oxygen, silicon, and manganese in the metal phase are available, as are activity data for the MnO-SiO2, FeO-SiO2, and FeO-MnO binary systems. A further objective was to demonstrate in a specific example how gaps in the data may be filled by judicious interpolation, and how the Gibbs-Schuhmann method is applied to obtain activities in ternary systems. The rigorous derivation of the latter, requiring considerable facility in handling partial differential equations, tends to mask the real simplicity of the method, and repel the very engineers and experimenters who would benefit the most from its use. I) GENERAL PROCEDURE Deoxidation of steel with silicon and manganese results in the formation of two phases, metal and oxide. The number of components is four—Fe, Mn, Si, and 0. The phase rule then gives the number of degrees of freedom: If temperature and pressure are fixed, 2 deg of freedom remain. Consequently, it suffices to fix the concentration of two of the components of the system for all the concentrations to be determined and, at least in principle, calculable. The practical problem is then to discover a straightforward method of calculation with a minimum of trial and error solutions. The type of reactions to be dealt with are like the following: Si (in steel) + 2 O(in steel) = SiO2(in oxide phase) The standard free energy of this reaction is readily obtained from the literature, so that the equilibrium constant can be calculated by the expression: Since the metallurgist is concerned with percentages rather than activities, a real solution requires information that will permit activities to be converted to concentrations. This information is fairly adequate for the elements dissolved in molten steel, but is not available for the FeO-MnO-SiO2 oxide system. Therefore, the first step in this study was to find the relation between activity and concentration for the three oxides making up the system. The next step was the calculation of slag and metal compositions that are in equilibrium with one another. As shown by the phase rule, it is sufficient to assume the values of two composition variables in order to calculate the rest. But which two are picked makes a vast difference in how difficult the calculation turns out to be, so that it is necessary to make preliminary trial of several routes to find the easiest one. A convenient method is to begin with the slag, and to pick FeO concentration and that of one of the other oxides. Starting with the relation between oxygen dissolved in the liquid steel and FeO in the slag permits a good first estimate to be made of the oxygen content of the steel in equilibrium with FeO, because the iron content being fairly close to 100 pct, Fe has an activity close to unity. Using this first estimate of oxygen activity, approximate values of the manganese and silicon contents of the melt are readily calculated from the appropriate equilibrium constants. A minor correction for the depar-

Jan 1, 1963

By J. H. Brophy, A. L. Prill, H. W. Hayden

An error lzas been found in the conventional way of determining the time exponent of linear shrinkage for the solution-precipitation stage of liquid-phase sintering. Large amounts of shrinkage due to initial rearrangenzent result in erroneously low exponents and tni si dentification of the rate-controlling process. Two alternative, mathematically correct, methods of calculation are applied to existing data on Fe-Cu, WC-Co, and Tic-Ni-Mo. This results in reidentifi-cation of the rate-controlling process and somewhat better agreement with related data. In each case the solution-precipitation process is solution-controlled and not diffusion-controlled. THE liquid-phase sintering process has been the object of a considerable amount of research for many years. Linear shrinkage vs time data at various sintering temperatures have been used recently in an attempt to identify the prevailing mass-transport processes in a number of metallic and nonmetallic systems. There is an analytical error inherent in the methods previously used for handling data during the "solution-precipitation" stage of shrinkage which must be recognized before the correct rate-controlling processes can be determined. It is the purpose of this paper to show how the error has affected previous conclusions and to suggest corrections. A number of mechanisms have been proposed to explain experimental observations during sintering in the presence of a liquid phase. The earliest of these is due to Price, Smithells, and williamsl who attributed the observed growth of the solid phase to the simultaneous solution of smaller particles and growth of larger particles. From the work of Lenel et al.2,3 and Gurland and Norton4 has come the suggestion that the liquid-phase sintering process may be divided for analysis into three steps: 1) rearrangement upon formation of the liquid phase; 2) solution and reprecipitation of the solid phase in the liquid; and 3) "coalescence" or a final stage of sintering, characteristically slower than the solution-precipitation process. The sequence of steps is shown schematically in Fig. 1. Kingery5 presented a thermodynamic and kinetic analysis of the first two "stages" of the liquid-phase sintering process in which the functional dependence of lineal shrink- age on time at temperature was used to identify the rate-controlling mass-transport process. Table I summarizes the time dependences and processes considered by Kingery.5 This method of data presentation has been employed by Kingery and coworkers for Fe-CU,6 WC-Co, and a number of nonmetallic systems," and bv Whalen and Humenik for Tic-Ni-Mo and Fe-cu.8 In each of these studies, the rate-controlling step during the "solution-precipitation" stage was identified from the slope of the curve in that stage on a logarithmic plot such as Fig. 1. However, in all of the previous studies, at a certain composition, relatively large amounts of shrinkage due to rearrangement preceded the solution-precipitation stage. Under these conditions, the larger the amount of rearrangement shrinkage the

Jan 1, 1965

By G. F. Comstock

A serious disagreement as to the effect of titanium on the hardenability of steel exists in published references to this subject. Kramer, Hafner and Toleman reported1 that acid-soluble titanium decreased the hardenability, with multiplying factors less than unity according to Grossmann's system for calculating hardenability from the composition. Crafts and Lamont, on the other hand, showed2 how titanium increased the hardenability, with multiplying fdctors up to nearly I.; for about 0.1 per cent titanium, though reducing the hardenability with higher titanium. Their data, however, were obtained almost exclusively from steels containing more than 1.4 per cent manganese, and thus should be considered as applying mainly to manganese steels. Likewise, the results of Kramer, Hafner and Toleman regarding titanium are subject to the limitation that although they eliminated the effect of the insoluble titanium compounds from their calculations, they did not make a similar correc- tion for the carbon that was combined with titanium and therefore occurred in a similarly ineffective form. It is suggested by the literature referred to that titanium may have different effects on hardenability, depending on the mode of its occurrence in the steel. The different effects on strength, ductility, etc., have already been discussed by the author.3 In the present discussion some comparisons, on the basis of hardenability as revealed by the Jominy end-quench test, are given between three titanium and two non-titanium steels heat-treated in the same ways, and between other titanium steels heat-treated in several different ways. Comparison of Plain-carbon, Vanadium and Titanium Steels The five steels used for these experiments were cominercially melted and rolled products received in the form of 1.5-in. rounds from three different mills. Their analyses are given in Table I. Steels 2, 3, and 4 are from the same basic electric heat1 containing 0.009 per cent of phosphorus and the same amount of sulphur. They were made by adding aluminum and low-carbon ferrotitanium to different ingots. No. I is a plain carbon

Jan 1, 1947

By G. F. Comstock

A serious disagreement as to the effect of titanium on the hardenability of steel exists in published references to this subject. Kramer, Hafner and Toleman reported1 that acid-soluble titanium decreased the hardenability, with multiplying factors less than unity according to Grossmann's system for calculating hardenability from the composition. Crafts and Lamont, on the other hand, showed2 how titanium increased the hardenability, with multiplying fdctors up to nearly I.; for about 0.1 per cent titanium, though reducing the hardenability with higher titanium. Their data, however, were obtained almost exclusively from steels containing more than 1.4 per cent manganese, and thus should be considered as applying mainly to manganese steels. Likewise, the results of Kramer, Hafner and Toleman regarding titanium are subject to the limitation that although they eliminated the effect of the insoluble titanium compounds from their calculations, they did not make a similar correc- tion for the carbon that was combined with titanium and therefore occurred in a similarly ineffective form. It is suggested by the literature referred to that titanium may have different effects on hardenability, depending on the mode of its occurrence in the steel. The different effects on strength, ductility, etc., have already been discussed by the author.3 In the present discussion some comparisons, on the basis of hardenability as revealed by the Jominy end-quench test, are given between three titanium and two non-titanium steels heat-treated in the same ways, and between other titanium steels heat-treated in several different ways. Comparison of Plain-carbon, Vanadium and Titanium Steels The five steels used for these experiments were cominercially melted and rolled products received in the form of 1.5-in. rounds from three different mills. Their analyses are given in Table I. Steels 2, 3, and 4 are from the same basic electric heat1 containing 0.009 per cent of phosphorus and the same amount of sulphur. They were made by adding aluminum and low-carbon ferrotitanium to different ingots. No. I is a plain carbon

Jan 1, 1947

By D. A. J. Swinkels

The problem of determining oxygen levels in liquid steel to aid in deoxidation control has received general attention for a number of years. Work in this direction started at the B.H.P. Central Research Laboratories early in 1967 with an evaluation of sampling techniques followed by vacuum fusion analysis to determine the oxygen content of the samples (1). It was found that these techniques had a number of drawbacks if they were to be used for deoxidation control. The method of analysis was rather too slow to allow effective control and measured total oxygen level rather than dissolved oxygen. Furthermore, the results were found to be very variable due to slag entrainment in the samples. Attention therefore turned to the galvanic cell method using a solid oxygen ion conductive electrolyte such as cubic stabilised zirconia. The ionic conductivity properties of electrolytes such as (ZrO2) 85 (CaO).15 had been studied by a number of investigators and had already been applied to the measurement of oxygen activity in gases, in lower melting metals such as copper, lead, tin, silver, alkali metals and indeed the first studies in steel had been made (2,3). Since then the results of a number of studies in the development of an expendable oxygen probe for steel have been reported (4-9).

Jan 1, 1972

By Eric Jette

THE unusual physical, electrical and magnetic properties of the iron-nickel alloys has given rise to a voluminous literature. This work will be reviewed critically in "The Alloys of Iron and Nickel," a monograph of the Alloys of Iron Research Series, soon to be published. In what follows we shall therefore confine ourselves to those of the earlier investi-gations that involved the use of X-ray crystal-structure methods. The earliest X-ray work on the iron-nickel system was by Miss Andrews1. Using the powder method of X-ray analysis purely as a means of identifying the phases present, she located a region between 20 and 30 weight per cent nickel in which body-centered and face-centered phases coexisted. No lattice constants nor details of heat-treat-ment were reported. Bain2 also reported some qualitative observations. McKeehan3 made a systematic investigation over the whole of the system, giving many of his alloys four and some five different heat-treatments. In alloys furnace-cooled from 900° to 950° C. he found two coexisting phases between 0.15 and 30 per cent nickel. The precision of the lattice-constant measurements was low in comparison with what can be obtained today.. Even for alloys of the same heat-treatment, differences in the constants were often between two and ten parts per thousand. In regions where no change of lattice constant with heat-treatment should occur, differences of the same order of magnitude were found. Since the maximum change in the lattice constant of nickel with change of composition is only about 2 per cent of the constant for pure nickel, these variations in the constants for a given alloy cause the points

Jan 1, 1936

By T. L. Loucks, E. T. Guerrero

Pressure drop characteristics in a system composed of two adjacent concentric regions of different permeability were studied. The differential equations for continuity of mass flow in the two regions were solved using the Laplace transformation and the necessary boundary conditions to give the pressure distribution in the composite reservoir, the resulting equation for pressure drop at the inner boundary was evaluated for a variety of composite reservoirs and compared with the results for a uniform reservoir. From this study it was found that under certain conditions the permeability in both zones, as well as the size of the inner zone, can be determined from the pressure drop curve. INTRODUCTION The theory for the pressure distribution and pressure build-up behavior of a well producing a single, slightly compressible fluid from infinite and finite homogeneous reservoirs was presented by Hornerl and Miller, Dyes and Hutchinson.2 Extensions on this original work to provide improved and extended interpretations and better agreement between theory and observed results have been made by Matthews, et a1,3 van Everdingen,4 Gladfelter, et al5 Stegemeierand Matthews,6 Hurst and Guerrero,7 and Perrine.8 More recently Lefkovits, et al,9 studied pressure build-up behavior in bounded reservoirs composed of stratified layers. Houpeurtl0 has suggested various approaches to the general problem of variable permeability and porosity but presented no analytic solutions for particular permeability variations. Albert, Jaisson and Marionll studied the finite composite reservoir and presented numerical solutions to the unsteady-state case and an analytical solution valid only for large times. They also studied the so-called pseudo-steady state for several examples of radial permeability variations. Very similar examples have been treated in the unsteady state with application to pressure build-up by Loucks in an unpublished manuscript. More recently Hurst12 has presented the complete point-sink solution (valid for all times) for the infinite composite reservoir. He applied these solutions to interference between oil fields along with an even more elegant application of his explicit solution to the material-balance equation including water influx. Mortada 13 approaches the same application by avoiding the point-source limitation but gives the solution for the aquifer region which is valid only for large times. Hopkinson, Natanson and Temple14 have treated both the finite and infinite composite reservoir obtaining the pressure distribution for the inner zone valid for large times. This paper presents a theoretical study of the pressure distribution in an infinite composite reservoir composed of two adjacent concentric regions of different permeability. The object was to determine the manner in which pressure drop at the inner boundary of a composite reservoir depends upon time, the permeability of each zone and the size of the inner zone. Expressions for the pressure distribution in both zones are developed which take into account the radius of the sink and are valid for small times as well as large times. It was felt that an understanding of the pressure drop behavior in various composite reservoirs would be of assistance in the interpretation of some pressure build-up curves which do not behave according to the theory derived for uniform systems. Often the region surrounding the wellbore is either more permeable or less permeable than the reservoir because of the various drilling and completion practices. The effects of reduced permeability due to drilling-fluid invasion and of increased permeability due to fracturing or acidizing need to be more carefully defined. Therefore, an equation for the pressure drop in a composite reservoir was developed, and the effects of both the permeability in each zone and the size of the inner zone were studied. STATEMENT AND SOLUTION OF PROBLEM BOUNDARY CONDITIONS AND ASSUMPTIONS The physical system studied was a composite

By G. Krauss, W. Pitsch

The fine structure of the bcc martensite formed in an Fe-33 wt pct ATi single crystal of arrstenite is sho~on by transmission electron microscoPy to consist of combinations of transformation twins, stacking faults, deformation twins, and regular arrays of parallel screw dislocations. These structures constitute evidence for the multiple lattice-invariant deformations which operating during the formation of martensite could produce the real habit-plane scatter measured by a two-surface analysis of the plates formed in the single crystal of this investigation and reported in the literature for other Fe-Ni rnartensites. CRYSTALLOGRAPHIC theories1,2 of martensitic transformation show that the habit plane of martensite in a parent lattice is dependent in part upon an inhomogeneous distortion or lattice-invariant deformation which takes place on a fine scale within a martensite plate during its formation. Several recent theoretical papers3,4 have addressed themselves to an analysis of a wide variety of conceivable lat-tice-invarient deformations and the habit planes which they produce, while experimental investigation have been concerned with either the measurement of habit planes or the description and identification of the martensitic fine structure which reflects the nature of the lattice-invariant deformation operating during transformation. In Fe-Ni alloys with subzero Ms temperatures, the group of alloys with which this paper concerns itself, habit planes have often been found to scatter an amount greater than might be expected from possible experimental errors,5-7 and fine twinning has been identified as a major constituent of the fine structure of martensite.8-11 It has been suggested3,4 that more than one type of invariant shear occurs during martensitic transformation. This possibility has been experimentally supported12,13 by the observation of both dislocation configurations and twinning in a single martensite plate. The purpose of this paper is to report additional evidence for multiple lattice-invariant deformations in martensite and so to account for the real scatter in the habit planes of the martensite plates formed in Fe-Ni alloys. EXPERIMENTAL PROCEDURE The Fe-Ni single crystal was produced by pulling a high-purity iron and nickel charge through a single-crystal vacuum furnace in an alumina crucible. The crystal was double-melted to promote homogeneity and to increase its size by further additions on the second pass. In its final form the crystal was 4 cm in diam and 5 cm long. The nickel and carbon contents were analyzed at 32.9 and 0.006 wt pct, respectively. The austenite of this alloy first transformed to martensite by bursts at about -120°C, and, to preserve as much of the austenite as possible, all transformation was performed just below -120°C. Some observations were made on transformed samples which had been heated for 2 min at 340°C. It is assumed that the features of the martensite of these samples, Figs. 1 and 4, are the same as those of the as-quenched martensite. Orientation of the crystal by X-ray diffraction established 10.735 0.609 0.3161? as the axis of the crystal, an orientation that was checked within 2 deg by neutron diffraction. Further checks by electron diffraction of samples cut normal to the axis confirmed this orientation within the larger limits of error inherent in electron diffraction of thin foils. The X-ray orientation was the one used for the two-surface analysis of the martensite habit planes. A two-surface analysis was performed on the quadrant of the single crystal which had been oriented by both X-ray and neutron-diffraction techniques. Photomicrographs at X50 were made on two surfaces along an edge 2 cm long. Fiducial marks and the fact that many of the plates were almost completely surrounded by retained austenite made good matching of individual plates on two surfaces possible. The habit-plane trace on a surface was taken as the best line parallel to the long axis of a plate. A measure of the accuracy afforded by this criterion was provided by a family of very large plates which appeared at intervals along the entire 2 cm length of the edge. The plates all had habit-plane traces within 2 deg of one another. Many of the plates did not show midribs and, therefore, the use of midribs7 to represent habit-plane traces was not feasible in this investigation. The over-all experimental accuracy is estimated to be better than ±2 deg. Samples for transmission examination in a Siemens Elmiskop I at 100 kv were prepared by cutting 2-mm-thick discs from the single crystal, removing about 0.5 mm by chemical polishing,14 trans-

Jan 1, 1965

By E. P. Pfleider

DIAMOND drill research work was initiated at the School of Mines, University of Minnesota, in late 1949. The Drilling Symposium held in Duluth that spring highlighted the problem of high cost and core recovery and the need for controlled testing. An advisory committee made up of informed representatives of both mining companies and drilling companies was formed to suggest and advise on a program of drill research. A Hy-Mac hydraulic drill unit, see Fig. 1, especially designed for experimental testing, was obtained for this work by the School of Mines through the courtesy of the Carboloy Co. It is an extremely flexible unit, capable of exerting a forward thrust of about 1750 lb and turning at speeds from 650 to 2200 rpm. The feed arrangement is so designed that the advance can be set either at a constant rate or permitted to vary at a fixed pressure, see Fig. 2. The

Jan 1, 1952

By L. R. Gremillion, G. H. McClellan

Chemical and mineralogical data on 25 apatitic phosphate ores of diverse origins from commerical deposits around the world were widely variable. From 14 to 18 chemical constituents of each sample were determined, and each sample contained four to ten mineral phases. Altogether there were 34 different mineral phases, many of which occurred in only one sample. Samples contained varieties of francolites, fluorapatites, and mixed hydroxyfluorapatites. The apatite compositions calculated from chemical data showed that certain types of substitutions were characteristic of different apatite varieties, but every variety had some degree of substitution of (CO3)2- for (PO4)3-, and the P205 contents of the apatites ranged from 35.1 %for a North Carolina apatite to 41.9% for a Missouri apatite. In a concentrate with a grade of 32% P2O5, the North Carolina sample should contain about 8.7% gangue and the Missouri sample about 23.7% gangue. To optimize the digestion process of a phosphate ore, it is necessary to consider the dissolution behaviors of different mineral phases during acidulation and their possible effects on chemical properties of a fertilizer intermediate. In the production of wet-process acids or superphosphates, acidulation of certain minerals may cause foaming and formation of sludge, filtration, corrosion, and handling problems.

Jan 1, 1982

By W. M. Gray

The determination of the state of stress existing at a point in any solid body requires the determination of the six components of the stress tensor relative to a convenient set of axes. One general method of doing this in rock is to make strain or deformation measurements associated with local relief of stress in a number of boreholes penetrating a limited volume in the vicinity of the point at which the stress is to be determined. The stress is assumed to be constant throughout this volume. Leeman1 has described a number of the instruments that have been developed for making deformation or strain measurements in boreholes. Panek2 has described the application of statistical methods to the determination of the average components of ground stress from sets of measurements made in boreholes by means of deformation meters of the type developed by the U.S. Bureau of Mines. In this paper attention is given initially to the strain cell developed for use on the flattened ends of boreholes by the Council for Scientific and Industrial Research (CSIR) , South Africa. The equations required for evaluating the average components of ground stress from measurements made by means of the CSIR strain cell are derived. These equations are similar in form to those applying to measurements made by the borehole deformation meter developed by the U.S. Bureau of Mines. The results of an investigation of the properties of the equations are described. These results are important in the practical use of both the instruments mentioned above and any instrument based on similar principles.

Jan 1, 1968

By Fred W. Gordon

Apart from the character of pig-iron to be manufactured, other than that it shall be well reduced and open-grained, the selection of the materials should be such as to produce it at the lowest cost. As a rule, the sources of fuels and limestones are not so extensively varied as those of the ores. Many Eastern furnaces are now using Lake Superior ores, and but recently a part of the supply came from foreign ports. It is, however, of the highest importance that the character of fuels and limestones, as well as ores, should be carefully considered in determining their value and making judicious selection among those available. The formulas here offered are based upon the assumption that the heat-requirements for a given mixture are measured by a constant required by the oxide of iron, added to that required for a unit of slag, multiplied by the weight of that slag per unit of iron. The heat-requirements for oxide of iron per unit of pig-iron made are assumed to be 2854 centigrade units. This is taken from the careful analysis of Sir Lowthian Bell, and, so far as the writer is able to determine, is very nearly correct. Dividing this by the quantity of heat that may be evolved and utilized within the furnace per unit of carbon, determines the quantity of carbon required per unit of pigiron ; and if to this be added the quantity of carbon absorbed by the pig-iron, the total requirements in carbon are determined, on the assumption that pure oxide of iron is reduced with pure carbon by the ordinary process of the blast-furnace. Calculating the quantity of slag that would be made from a given mixture of ores, smelted with a given impure fuel and fluxed with a given impure limestone, multiplying this weight of slag by the heat-requirements of its unit (taken at 1050 C. H. U.), and dividing the product by the heat-units evolved and utilized within the furnace per unit of carbon, will determine the quantity of carbon required per unit of pig-iron for the slag.

Jan 1, 1893

By Albert Ladd Colby

PAGE I. Introduction,...........577 11. PRocess of Manufacture. 1. American Specifications. 2. Foreign Specifications, . ......... 580 III. Chemical Properties. I. Chemical Composition: (a) American Specifications ; (b) Foreign Specifications. 2. Chemical Analysis: (a) American Specifications ; (b) Foreign Specifications ; (c) Number of Analyses Required ; (d) Sample for Analysis ; (e) Check-Analyses Impracticable ; (f) Rejection Solely on Variation in Com-' position,............581 IV. Physical Properties. 1. Drop-Test and Drop-Testing Hachine: (a) American Specifications ; (b) Foreign Specifications ; (c) Limits in Deflection. 2. Tensile Test: (a) American Specifications; (b) Foreign Specifications ; (c) Test-Pieces are not Representative ; (d) Specified Tensile Strength is Affected by the Section ; (e) BpeciBed Tensile Strength is Often Inconsistent with Specified Chemistry ; (f) Specified Tensile Strength is Often Inconsistent with Specified Elongation ; (g) Amount of Tensile Testing Required is Excessive ; (11) Conclusions. 3. Dead-Weight Test: (a) American Specifications; (b) Foreign Specifications; (c) Number of Tests Specified. 4. Bending-Test: ((1) American Specifications ; (b) Foreign Specifications,..........589 V. Section. 1. American Specifications. 2. Foreign Specifications: (a) Templets ; (b) Sample Piece of Rail; (c) Allowable Variation from Templet,...........601 VI. Weight. 1. American Specifications. 2. Foreign Specifications,. . 603 VII. Length. 1. American Specifications. 2. Foreign Specifications, . . 604 VIII. Drilling. 1. American Specifications. 2. Foreign Specifications, . 604 IX. Finish. 1. American Specifications. 2. Foreign Specifications, . . 50.5 X. Branding. 1. American Specifications. 2. Foreign Specifications : (a) Data to be Rolled in Raised Letters on Web of Rail ; (b) Marking of the Blow-Number on Each Rail; (c) Additional Marking and Painting of Rails,........605 XI. Inspection. 1. American Specifications. 2. Foreign Specifications: (a) Prior Notice of Rolling; (b) Free Access to the Works ; (c) Cost of Inspection, Analyses and Tests to be Borne by the Manufacturer ; (d) Rails after Inspection by Manufacturer to be Sorted into Lots Prior to Inspection by the Engineer ; (e) Disposition of Rejected

Jan 1, 1907

By C. K. Donoho

SILICON is used in almost all commercial steels; up to about 0.20 pct in killed wrought steels and 0.50 pct in steel castings. Above about 0.50 pct in wrought steels and 0.70 pct in cast steels, silicon is considered an alloy. As an alloy, silicon is useful for several purposes: (I) for its effect on magnetic properties of parts for electrical apparatus; (2) for increasing the yield strength of carbon and low-alloy steels without too much sacrifice of ductility and weldability; (3) for adding hardness and toughness to spring and chisel steels; (4) for adding resistance to scaling and carburization to heat-resistant steels; and (5) for its graphitizing effect in graphitic steels. In acid electric steels for casting we are principally interested in the effect listed second; i.e., increase of strength with minimum sacrifice of ductility.

Jan 1, 1947