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By M. S. Klima, P. T. Luckie

Interfacing new or improved unit operations SUBMODULES with the EXECUTIVE of a macro analysis simulator usually requires modification of the input data. For example, particle processing SUBMODULES that are sufficiently general in nature to provide useful predictions require input data for rather narrow size fractions. Such data is not always available for the EXECUTIVE and must therefore be generated by the SUBMODULE. A successful interface to allow incorporation of a new SUBMODULE for comminution and one for classification in a general stream state flowsheet simulator is presented. The general nature of the SUBMODULES, as well as the logic of expanding and contracting the required data input is discussed.

Jan 1, 1983

By E. O. Chartkoff

IN 1926 one of the authors published researches on the determination and description of the iron-tungsten and iron-molybdenum systems,1 including the equilibrium diagrams. In 1929, further work was carried on, including the examination by X-rays, which is recorded here. Measurements were made of changes in lattice parameters in the solid solutions. Precipitation from the solid solution and the accompanying changes in hardness were studied as well as the formation of the intermetallic compound phases upon sintering a mixture of metal powders.

Jan 1, 1930

By K. E. Brown, F. W. Jessen

It is deemed feasible to store atomic reactor fuel wastes in salt dome cavities when the differential pressure acting on the cavity does not exceed 3,000 psi and the temperature is less than 400°F. Tests at pressure increments of 1,000 psi were conducted on a 2-in, cylindrical cavity contained in a 6-in. long X 6-in. diameter salt core. The cavity exhibited stability under pressures up to 3,000 psi and temperatures to 300°F. At temperature ranges of 100 to 400°F and with pressures of 5,000 psi and above continuous deformation of the cavity resulted. Initial movement of the salt was observed at all pressares. This was evidenced by vertical deformation and cavity size reduction. INTRODUCTION The development of storage techniques for safe disposal of atomic reactor fuel wastes is a goal of the Atomic Energy Commission. Salt domes have been used successfully for storage of liquefied petroleum gases and hence should prove to be suitable for liquid waste products of atomic reactors. The purpose of the following work is to evaluate the practicability of utilizing salt dome cavities for such wastes and to de-termine particularly the effect of pressure and temperature on a salt cavity. This work represents a part of a comprehensive study covering the over-all problem of storing re- actor fuel wastes in salt domes and/ or salt beds. The problem of accurately determining the stresses which exist in rocks in the earth's crust is indeed a complex one. Theoretical studies have differed widely in many of the basic assumptions about the physical properties of the rock itself. Some solutions of problems in underground stress analysis assume that rock is elastic, homogeneous and isotropic in character; others assume that rock possesses plastic, viscous, elasticovis-cous properties, or a combination thereof. Experimental evidence has shown that salt possesses plastic, viscous and elasticoviscous properties.' Recent work has shown that salt becomes more plastic with temperature.' APPARATUS AND PROCEDURE For experimental study a cylindrical cavity was chosen for analysis since it provided maximum volume per unit of depth with constant diameter. This particular cavity shape, allowing for irregularities, can be easily leached out of salt domes in field operations. For the purpose of approaching underground storage conditions as nearly as possible, the following factors were considered: (1) control of pressure and temperatures, (2) measurements of temperature gradients throughout salt mass, and (3) measurement of structural stability of salt cavities. In order to obtain triaxial pressure on the salt cavity without resorting to the application of fluid pressure directly on the salt mass, a system was designed whereby the same effect could be produced through axial loading only. By cutting a core to close dimensions to fit a steel test cylinder and applying axial pressure, a lateral pressure was obtained. This equipment is shown in Figs 1 and 2. A steel cylinder was made from

EXECUTIVE COMMITTEES OF LOCAL SECTIONS New York L. W. FRANCIS, Chairman, WILLARD S. MORSE, Vice-Chairman. THOMAS -T. READ, Secretary, Woolworth Bldg., New York: N. Y. P. A. MOSMAN, Treasurer. LOUIS D: HUNTOON. Boston HENRY L. SMYTH, Chairman. ALFRED C. LANE, Vice-Chairman. AUGUSTUS H. EUSTIS, Secretary-Treasurer, 131 State St., Boston, Mass. TIMOTHY W. SPRAGUE, HENRY A. WENTWORTH. Columbia F. A. THOMSON, Chairman. GEORGE W. RODDEWIG, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. R. S. McCAFFERY, S. H. RICHARDSON.

Jan 10, 1914

By A. H. Geisler, J. H. Keeler

Preferred orientations in rolled and annealed titanium sheets were determined by the Geiger counter spectrometer X-ray diffraction technique. Five annealing textures dependent upon the temperature range of annealing were found, and in order of increasing annealing temperature pendent upon the temperature range are: 1—a deformation like texture, 2—a rotated inorder a-recrystallization temperature texture, 3-a retained u-recrysraIlization texture, on annealing at lower temperatures of the ß-region, 4—a transformation texture based on recrystallized a and predicted by the Burgers' relationship, and 5—a ,ß-cube texture. These results are examined in terms of current theories of recrystallization textures. UMEROUS investigators have described the tex- ture obtained by cold rolling the hexagonal metals, titanium, zirconium, and beryllium, which have c/a ratios less than that of ideal packing, 1.633. The basal planes are rotated out of the rolling plane, about the rolling direction, so that the basal poles are tilted toward the transverse direction as shown schematically in Fig. la. In all instances but one,' it was also reported that the [1010] direction was parallel to the rolling direction (see Fig. lb). Hot rolling has been reported as causing a similar tilt of the basal poles in the transverse direction (see Fig. la) and causing the [1010] direction also to be parallel to the rolling direction as shown schematically in Fig. lb. Annealing after deformation does not appreciably change the tilt of the basal poles in the transverse direction." Beryllium2-7 continues to have the [1010] direction in the rolling direction after annealing, and similar observations for titanium and zirconium' . have been reported for annealing at fairly low temperatures, again as in Fig. lb. At higher annealing temperatures, however, the recrystallized grains of titanium" and zirconium have an orientation such that the [1120] direction is approximately in the rolling direction, although the basal poles are still inclined in the transverse direction. Figs. la and lc show the resulting orientations schematically. This change in orientation has been described as a nominally ±30° rotation of the hexagonal crystallites about the basal poles of the cold rolled texture and is apparent from the results which are summarized in Table I for investigations with the X-ray diffraction technique employing film. The angles y, , and ß are indicated in Fig. 2 which represents the stereographic projection of (1070) poles for the mean orientation of a pole figure. Texture determinations for titanium using the Geiger counter spectrometer have provided similar results except that in some instances additional components of the texture were proposed, as shown by the summary of data in the upper half of Table 11. On the other hand, the spectrometer technique, when applied to zirconium,* has revealed a splitting Recently completed studies of the textures of annealed zirconium", show zirconium to possess textures very similar to those reported here for titanium. Therefore, much of this discussion will include zirconium by virtue of its close similarity to titanium in pref erred orientations. of the intense areas of the pole figure for samples annealed at 600°C. This splitting could be described by a 7" rotation of the tilt axis about the normal to the rolling plane. Such a splitting for the annealed texture relative to the cold rolled texture was not observed in other determinations for either zirconium or titanium using the less sensitive film X-ray methoe and makes the relationship between the two types of texture more complex than the simple rotation about the (0001) pole based on film work. The more precise investigations on zirconium permit the descriptions in the lower part of Table 11, which show that the texture depends quantitatively on the temperature of annealing. When zirconium is annealed at temperatures up to 400°C, the texture is similar to the cold rolled texture, while annealing in the range 500" to 900°C produces a texture which is only approximately described as [11%] in the rolling direction. More precisely described results for zirconium show that the two types of splitting ( 1—about an axis in the rolling plane through an angle given in the second column in Table II and 2—about the normal to the rolling plane through an angle given in the third column of Table 11) depend on annealing temperature. The [1120 is the rolling direction only when the annealing temperature is in the vicinity of 900°C

Jan 1, 1957

By M. Cohen, R. J. Teitel

There is considerable interest in beryllium because of its low density (1.84 g per cu cm), high modulus of elasticity (40 X 106 psi), high melting point (1280°C), and special nuclear characteristics. Moreover, it has fair resistance to corrosion and oxidation. However, the purest beryllium known to the authors is relatively brittle at room temperature, and cannot be fabricated readily. The search for improved properties leads naturally to investigations of beryllium alloys and the phase relationships upon which they are based. The present paper is concerned with the alloys of beryllium and iron, primarily from the standpoint of the equilibrium diagram. Iron was selected (1) because of its all-round importance in metallurgy, and (2) because the beryllium-iron system is known to be quite complex. The most recent diagram in the literature is that of Gaev and Sokolov,' and covers only the iron-rich end up to 16 wt pct beryllium. Beryllium markedly restricts the austenitic field, closing the gamma loop at about 0.4 wt pct (3 at. pct). On the other hand, beryllium is soluble in a-ferrite up to a maximum of 7.5 wt pct (34 at. pct) at the eutectic temperature of 1160"C. The eutectic composition lies at 10 wt pct beryllium (42 at. pct) and corresponds to a mixture of or and FeBez (called j3 in the present paper). The solid solubility of beryllium in the a phase decreases with decreasing temperature, and makes precipitation-hardening possible. These findings substantiate the earlier work of Oester-held,2 Wever and Mueller3 and Laissus.4 In addition to the FeBe2 (ß) mentioned above, Misch6 has reported on FeBes, and indicated evidence for another compound containing still more beryllium. A preliminary diagram by Gordon,5 not hitherto published, is given in Fig 1. Besides the phases previously named, there are shown a solid solution of extended range (e), a compound of limited solubility (t), and a high temperature phase (7). Beryllium is designated as 8. The t field contains the compound composition FeBea, and the f phase undoubtedly corresponds to the beryllium-rich compound found by Misch.6 The region around the { phase was proposed by R. J. Teitel based on Gordon's data. The details of the diagram are self-explanatory. It was the unusual complexity of this system that prompted the authors to undertake the present studies. By the same token, more emphasis was placed on the beryllium-rich than the iron-rich end of the diagram. Exprimental Details RAW MATERIALS The beryllium employed in this investigation was one of the purest grades available. Its chemical analysis after vacuum melting is given in Table 1. The metal assayed 99.4 wt pct beryllium. Vacuum melted electrolytic iron of purity shown in Table 1 was the source of iron.

Jan 1, 1950

By R. M. Goldhoff, H. J. Beattie

The high-temperature properties of a 1 Cr-Mo-V forging steel are described. A series of controlled heat treatments was designed to delineate the effects of austenitizing and tempering treatments, temile strength, and grain size on such properties. Studies indicate that the mechanical properties and their varlations under creep can be described by the initial metallurgical structures and their changes droPirzg exposure, particulavly the carbide reactions. Such structures are described and correlated with the mechanical properties. FOR many years the large steam turbine industry has relied on the 1 Cr-Mo-V type forging steel for critical applications. Because of its adequate heat resistance and relative economy, it is currently in use in the temperature range up to about 1050" to 1075°F. Attempts to understand the large property variations attainable in this steel involve the structural modifications due to the wide latitude in its heat treatment. The heat treatment essentially involves a two-step process which includes solution-ing of carbides in the austenite range followed by a suitable tempering treatment below the critical to adjust the level of properties. The latter step is referred to as "secondary hardening" and is basically an ordinary aging reaction involving carbides. In the commercial heat treatment of large components of such steel, homogenizing and stress-relief anneals may be included and have some importance in determining subsequent properties. Several studies of the engineering properties of this steel as a function of transformation micro-structure have been reported.1 3 However, in this steel the carbide reactions, which are a function of composition and heat treatment, appear to be the property-controlling factor rather than the micro-structure defined as a transformation product. Thus, the tempering resistance of this type of alloy steel is mainly a function of the size and distribution of alloy carbides.4 However, it is also necessary to consider the stability of the microstructure and the effect of dynamic carbide reactions on subsequent properties. It is the purpose of this paper to show the interdependence of properties and corresponding structures, particularly carbide reactions, developed for a limited set of controlled heat-treatment conditions applied to 1 Cr-Mo-V steel. MATERIALS AND PROCEDURE The material for this work came from a large production forging whose chemical composition is shown in Table I. The property data accumulated on this steel as a function of heat treatment were room-temperature tensile and smooth- and notch-bar creep rupture at 1050°F (notch geometry: shank diameter = 0.357 in., depth = 50 pct, radius = 0.005 in.). To achieve controlled structural variations the temperature and time of both austenitizing and tempering were varied in a manner to produce a series of eight steels each at one of two grain sizes and one of two hardness levels in proper combination for valid comparisons. This will be clear upon examination of Table I. Structural studies involved the use of optical and electron microscopy as well as X-ray and selected-area electron diffraction. To reveal the nature of carbide precipitations, electrolytic extraction techniques were used with subsequent analysis of the residue by X-ray diffraction. Weight losses of the steel specimens during electrolysis were measured and successive chemical fractionations of the residues were applied and checked by X-ray examination. The details of fine structural distributions, morphologies, and crystallography of the precipitates as well as dislocation distributions were investigated by examining in the electron microscope three common types of preparation. a) Relief Replicas. Mechanically polished sections were etched in 2 pct nital, replicated with a nitrocellulose film, which was shadowed by chromium vapor deposited at a glancing angle of 20 deg. b) Extraction Replicas. A thin film of carbon was vapor-deposited on the polished and etched surface. The carbon films were then etched off and gathered on electron-microscope supporting grids. The carbides left imbedded in the carbon replica in their original distribution were then examined crystallo-graphically by selected-area electron diffraction. c) Thin Films. Specimens were mechanically ground and polished down to a thickness of 0.001 to 0.003 in. Final thinning was done electrolytically in a "chrome-acetic" electrolyte. When holes began to appear in the foil, the voltage was interrupted and applied in several 1-sec bursts. Sections of the foil between holes were thin enough to pass a 100-kv electron beam that carries an image.

Jan 1, 1965

By B. C. Wonsiewicz, W. W. Wilkening

Following a procedure proposed by Wheeler and Ireland, Plane stress yield loci were constructed from Knoob hardness numbers. Basically, six differently oriented hardness measurements were made on three orthogml surfaces through pure poly crystalline magnesium sheet, a magnesium single crystal, and sheet of the magnesium alloys: Mg + 0.5 pct Th, Mg + 4 pct Li, AZ31B, and EKOO. Hardness loci were found to be in poor agreement at small strains (E < 0.05) with loci established by a more rigorous technique. At larger strains (E - 0.10) the agreement is fair, but at this stage in deformation the conventional locus has lost much of the asymmetry that characterizes these anisotropic materials. Two effects which will lead to distortions in the Khn locus are discussed with reference to the geometry of plastic flow during a hardness test. DETERMINING a material&apos;s resistance to multiaxial loading is of interest not only from a structural design viewpoint but also from that of deformation processing. Unfortunately, the determination of the yield locus, although simple in principle, involves tedious procedures if the results are to be at all rigorous.&apos; The idea, first proposed by Wheeler and 1reland2 of determining the yield locus by means of six Knoop hardness impressions along the principal directions in a material has obvious appeal. It is simple, quick, and should be applicable to very thin sheets. If such a technique could be demonstrated to produce consistently reliable results, it would be of interest to both researcher and designer. Lee, Jabara, and ackofen have compared the yield locus determined by Knoop hardness measurements (the Khn locus) to a locus determined by more rigorous techniques. They found good agreement for two titanium alloys at a plastic strain of about 1 pct. The purpose of this paper is to investigate if the Khn locus construction is a reasonable approximation to the locus of a highly anisotropic material. Examples of such materials are magnesium and magnesium alloys which have severely distorted yield loci which in turn reflect markedly dfferent yield strength in different directions.&apos; In pure magnesium, for example, the yield stress in tension along the transverse direction may be four times the yield stress in compression in the same direction and twice the tensile yield stress in the rolling direction. Predicting such large differences ought to serve as a severe test of the Khn locus construction. EXPERIMENTAL PROCEDURES Samples of rolled sheet, 0.250 in. (6.35 mm) thick, of pure magnesium and four magnesium alloys (Mg experimental materials. The pure magnesium together with the lithium and thorium alloys were those used in the study of Kelley and Hosford. The grain size was ASTM number 4 for the pure magnesium and number 6 for the alloys. HARDNESS TESTING The materials were sectioned along the rolling and transverse planes, mounted in a quick setting resin, and mechanically polished. Most of the hardness tests were performed on a surface prepared by electro-polishing (30 pct nitric acid in methanol at 0°C and 20 v) with the exception of the AZ31B and EK00 alloys which were made directly on a metallographically polished surface. However, subsequent hardness tests on the same sample after heavily electropolishing, revealed essentially the same hardness as before. At least twenty Knoop hardness impressions under a 100-g load were made in each of the six orientations shown in Fig. 1. The average hardness number and standard deviation were then calculated for each orientation. CONVENTIONAL LOCUS CONSTRUCTION Yield loci were constructed using a technique described in detail by Lee and ackofen,&apos; in which the flow stress (stress at a given plastic strain) fixes the coordinates of a point on the locus and measurements of the strain ratio serve to establish the slope of the locus at that point. The loading paths which correspond to uniaxial tension or compression tests establish the four intercepts of the locus with the coordinate axes plus one point on the balanced biaxial tension line Tensile testing was performed along the rolling and transverse (r, t) directions. Samples had a uniform rectangular gage length 1 by 4 by 4 in. (25.4 by 6.35 by 6.35 mm) and were deformed at a strain rate of 3.33 x 104 sec-&apos;. The tests were interrupted periodically to unload the sample and measure the plastic strains by means of X-Y post yield strain gages. Compression tests in the rolling, transverse, and through-thickness (r, f, z) directions were performed on 1/4 in. (6.35 mm) cubes at an initial strain rate of 8.33 x sec-&apos;. Lubrication was provided by 0.002 in. (51 pm) Teflon sheet which was renewed after unloading for micrometer measurements used to calculate the strains.

Jan 1, 1970

With the signing of the armistice on Nov. 11, the direction of the main concentration of effort of the United States was changed. In order to win the war, all industrial efforts had to be organized and centralized. With the war won and peace in sight, this centralization of effort stopped and the full play of individual initiative was allowed to resume its sway in the community. During this period of reversal of direction of effort, there was a natural loss of momentum and the United States, as well as the rest of the world, is in for a period of readjustment. The immense progress that was made in one direction under the stress of the necessities of war, which focused the energies of a nation in one direction, is an outstanding example of what can be accomplished if a community with many varying interests can be united on one objective which it desires to attain. The realization that the fusing of many interests into one stream of effort is difficult should not prevent us from taking the long view ahead that is necessary in order to be able to measure the progress made. If we don&apos;t have a mountain peak to guide us, we are very likely to run in circles in the plain without reaching the goal to which we strive. The most efficient development of natural resources is an ideal that, from a material point of view, appeals to the engineer. This ideal includes giving of opportunities to everyone to take a share in the development of these resources.. It also contemplates rewarding foresight

Jan 4, 1919

By D. L. Feucht, R. L. Longini

The semiconductor heterojunction is considered in terms of simple models which may lead to an understanding of move complex heterojunctions. Metallurgical and electrical properties of hetero-junctions aye discussed including the interface structure, energy -band diagram, and carrier transbovt across the interface. It is found that in a heterojunction all mechanisms such as injection, tunneling, and junction recombination found in simple junctions play modified voles. INTERFACES between materials (grain boundaries, the electrical junction between two differently doped materials in a single crystal, the oxide-metal interface, or metal-metal junctions) are of considerable importance in many situations. These various interfaces all have one very fundamental thing in common. Quantum mechanically speaking, the wave functions of the electrons in one material may penetrate the other material but, in general, only to the extent of angstroms. From an electrical point of view the conduction mechanism changes as a current passes through such junctions. In some cases the change is tremendous, in others almost negligible. The interface, then, is the locus of a change of conduction mechanisms. Some of these, particularly in semiconductors, are well-understood. The ordinary p-n junction in a single crystal can be the locus of an injection mechanism or a tunneling process, depending on conditions. The mechanisms are probably best understood in semiconductors because of the possible simplified view of particlelike conduction. The bands are either nearly filled or nearly empty and band overlap is seldom involved. The same fundamentals are probably important in other situations too but they are very difficult to look at naively. Although the simple look at the semiconductor case only gives us a relatively rough picture which must then be refined, the other systems, which involve a more complex situation, immediately are in many ways too difficult. There are too many initial choices of complex systems and therefore it is not possible to be even reasonably certain of any one model. Because of the relative simplicity of semiconductors, their good and controllable structure, and because of the ability to make many measurements on them not normally available to either metals or insulators! they are probably the best understood materials. It is therefore desirable to use them as a tool to further the understanding of interfaces in general. Semiconductor-heterojunction concepts were first proposed by kroemer1 in 1957. This was followed several years later by reports on the fabrication and experimental characteristics of heterojunction structures by Anderson2 and Diedrich and jotten.3 I) THE HETEROJUNCTION STRUCTURE To get down to hardware, when we refer to a semiconductor heterojunction we imply that there exists an intimate contact between different semiconductor materials. We could put two pieces of material together, complete with oxide layers, we could remove the oxides, or we could even melt the interface and hopefully get wetting and a good "bond" on solidifying. In fact we could by some means grow a crystal of one material using the other as a seed. Essentially we are interested only in the last two because they are the simplest to look at analytically. The degree of perfection of fit varies greatly and is reflected somewhat in the arc welder&apos;s joint strength. The lattice match of the two materials, their orientation, and so forth. is obviously necessary for a good bond but so is the continuity of any polar bonds which are involved such as in the III-V semiconductors. The mechanical misfit between two similar lattices can be described in terms of edge dislocations. The edge-type dislocations must be very close together for the usual misfit and there must be dislocations for each of several different Burger&apos;s vectors in order to produce a lattice match. The .&apos;dangling bonds&apos;&apos; resulting will be involved in producing interface charge. Order of magnitude estimates of the charge density extrapolated from low densities of dislocations in homogeneous materials give 5 x 1013 cm-2 Ge-Si and 1 X 1012 cm-2 Ge-GaAs electronic charges. Edge dislocations also act as very active recombination centers between holes and electrons. One lattice "matching" difficulty usually exists even if two structures have essentially the same lattice constants as they will have different coefficients of therma1 expansion. Thus, on cooling from the usually high temperature of fabrication to room temperature, dislocations are produced, a good fit not existing at both temperatures. In brittle materials this shrinkage may even result in cracking. For the Ge-Si interface the mismatch is about 2 x 10 -6 per degree whereas it is less than 10"7 per degree between germanium and GaAs. The exact effect of the misfit is dependent on the thickness of the materials involved. For a very

Jan 1, 1965

By Ernest N. Patty, Sherwin F. Kelly

The present case history deals with the examination of an almost forgotten nickel prospect, near Winesap, Chelan County, Washington. Although the final results yielded no ore body of commercial importance, the integration of surface and underground exploration, geophysical survey and diamond drilling endow the story with interest. The program is significant because it is illustrative of how the most disappointing expenditures in mining exploration, the "not-finding" costs, could have been reduced had geophysical methods been applied at an appropriate stage in the prospecting work. The Chelan nickel deposit was discovered about 1900, on a sage-brush-covered hillside with a southerly slope, adjacent to Winesap Canyon; the paved highway now extending from Wenatchee northward, up the Columbia River and into Okanogan Valley, is only a mile away. After the deposit was found, three short prospect tunnels were driven into it, and the prospect then remained dormant for 40 years. No. x tunnel was 80 ft. long, running north into the hillside. For the first 35 ft. this adit exposed a typical, iron-stained gossan with streaks and stains of malachite, and small seams of water-soluble nickel sulphate. Beyond this, it encountered a relatively fresh peridotite, well mineralized with blebs of pentlandite. Systematic sampling yielded an average assay of 1.5 per cent nickel and 0.3 per cent copper. Down the hillside to the south and 35 ft. lower in elevation, No. 2 tunnel was driven under No. I and in the same direction, traversing 50 ft. of gneiss before it reached the peridotite. At this point the latter formation showed only scattered blebs of sulphides, not of commercial grade. To the west, on the same contour line as No. I tunnel, and 800 ft. around the hillside from it, No. 3 tunnel was driven 50 ft. into the hill to explore a strong gossan outcrop that assayed 0.5 per cent nickel (Fig. I). From the geological exposures on the hillside and in the tunnels, it appears that the main mass of the hill is formed of an ancient and altered gneiss complex. Into this, a sill-like injection of amphibolite (altered peridotite) was intruded, which, at least in some places, contains commercial quantities of nickel sulphide. Its structure is obscure, but it appears to dip into the hill at an angle of about 15°. In the vicinity of No. 3 tunnel a large dike of quartz diorite cuts the peridotite or amphibolite; about 140 ft. north of the portal of the tunnel, a dike of andesite 00 ft. wide cuts boldly up the hillside to break the continuity of the peridotite in that direction. The geological evidence available was not adequate to decide whether the peridotite forms a continuous sill, or occurs as isolated bodies in the gneiss. Not all of this peridotite carries commercial amounts of pentlandite, but if the mineral-

Jan 1, 1946

By Ernest N. Patty, Sherwin F. Kelly

The present case history deals with the examination of an almost forgotten nickel prospect, near Winesap, Chelan County, Washington. Although the final results yielded no ore body of commercial importance, the integration of surface and underground exploration, geophysical survey and diamond drilling endow the story with interest. The program is significant because it is illustrative of how the most disappointing expenditures in mining exploration, the "not-finding" costs, could have been reduced had geophysical methods been applied at an appropriate stage in the prospecting work. The Chelan nickel deposit was discovered about 1900, on a sage-brush-covered hillside with a southerly slope, adjacent to Winesap Canyon; the paved highway now extending from Wenatchee northward, up the Columbia River and into Okanogan Valley, is only a mile away. After the deposit was found, three short prospect tunnels were driven into it, and the prospect then remained dormant for 40 years. No. x tunnel was 80 ft. long, running north into the hillside. For the first 35 ft. this adit exposed a typical, iron-stained gossan with streaks and stains of malachite, and small seams of water-soluble nickel sulphate. Beyond this, it encountered a relatively fresh peridotite, well mineralized with blebs of pentlandite. Systematic sampling yielded an average assay of 1.5 per cent nickel and 0.3 per cent copper. Down the hillside to the south and 35 ft. lower in elevation, No. 2 tunnel was driven under No. I and in the same direction, traversing 50 ft. of gneiss before it reached the peridotite. At this point the latter formation showed only scattered blebs of sulphides, not of commercial grade. To the west, on the same contour line as No. I tunnel, and 800 ft. around the hillside from it, No. 3 tunnel was driven 50 ft. into the hill to explore a strong gossan outcrop that assayed 0.5 per cent nickel (Fig. I). From the geological exposures on the hillside and in the tunnels, it appears that the main mass of the hill is formed of an ancient and altered gneiss complex. Into this, a sill-like injection of amphibolite (altered peridotite) was intruded, which, at least in some places, contains commercial quantities of nickel sulphide. Its structure is obscure, but it appears to dip into the hill at an angle of about 15°. In the vicinity of No. 3 tunnel a large dike of quartz diorite cuts the peridotite or amphibolite; about 140 ft. north of the portal of the tunnel, a dike of andesite 00 ft. wide cuts boldly up the hillside to break the continuity of the peridotite in that direction. The geological evidence available was not adequate to decide whether the peridotite forms a continuous sill, or occurs as isolated bodies in the gneiss. Not all of this peridotite carries commercial amounts of pentlandite, but if the mineral-

Jan 1, 1946

By Robert F. Brindisi

There are approximately thirty to forty operating mills in the United States which are currently producing uranium yellow cake. This figure includes a significant number of in situ and by-product operations however the conventional acid leach flowsheet depicted in Figure 1 is the most common process used by domes- tic yellow cake producers. Ground ore is leached with sulphuric acid and the solids are separated from the pregnant liquor and washed in a series of counter- current decantation thickeners. After clarification of the pregnant liquor, uranium is recovered from the solvent extraction/stripping circuit by the addition of ammonia with precipitation of ammonium diuranate, or simply yellow cake. The yellow cake precipitate is then thickened in a conventional thickener before re- porting to the dewatering/washing unit operation. De- watered solids subsequently report to thermal drying, and clarified liquor from the dewatering/washing step is recycled to the yellow cake thickener. The yellow cake dewatering/washing unit operation is generally accomplished using either a solid bowl centrifuge or a rotary vacuum drum filter. In most cases the underflow from the yellow cake thickener is pumped to the dewatering/washing unit operation at approximately fifteen to twenty percent solids. For the purpose of this discussion ammonium diuranate, the product of ammonia precipitation from a conventional acid-leach uranium mill flow sheet, as discussed earlier, will be considered. With only slight adjustment this discussion will be equally applicable to sodium diuranate or uranium perioxide precipitates and to either in situ or by-product operations where such precipitates are generated. Some of the domestic uranium mills which have selected solid bowl centrifuges instead of vacuum drum filters for the dewatering/washing unit operations are listed in Figure 2. Why have these uranium mills, as well as others not listed, chosen to use the solid bowl centrifuge for this particular application? It is simply a matter of performance, reliability and economics. In the remainder of this paper the performance, initial cost, installation cost, maintenance and power consumption of both the solid bowl centrifuge and the rotary vacuum drum filter will be com- pared. In order to provide a consistent basis for comparison the appropriate sized (centrifuge or filter) unit for the dewatering/washing of 400 to 500 pounds per hour of yellow cake solids will be considered. Such a flow will usually be generated by a typical 3,000 ton per day (acid-leach) uranium mill.

Jan 1, 1980

By J. T. Williams

The equilibria in the V-Zr alloy system were investigated by solidus temperature determinations, thermal analysis, dilatometry, electrical resistance measurements, microscopic examination, and X-ray diffraction analysis. There is a eutectic reaction at 1230°C between a compound, V2Zr, and a solid solution containing 10 pct V in ß zirconium. V2Zr decomposes at 1300°C into liquid and a solid solution containing about 10 pct Zr in vanadium. The eutectic composition is probably about 30 pct V. A eutectoid reaction between V2 Zr and a zirconium takes place at 777°C at a very high rate. The eutectoid composition is 5 wt pct V. The limit of solubility of zirconium in vanadium was estimated to be 5 pct at 600°C. No attempt was made to determine the liquidus for the system. THE recent availability of large quantities of high purity zirconium has stimulated the study of zirconium binary systems. The equilibrium diagram for the V-Zr system has received little attention, however. Wallbauml appears to have made the first report concerning the equilibria in these alloys. He reported the existence of a compound, V2Zr, having the MgZn2 ((214) type of structure with a, = 5.277 kX and c° = 8.647 kX. Anderson, Hayes, Roberson, and Kroll2 made a survey of some potentially useful zirconium binary alloys and found that zirconium probably dissolves a small amount of vanadium. They reported the probable existence of a compound between the two elements and suggested that the zirconium-rich solid solution undergoes a eutectic reaction with this compound. Pfeil," in a critical review of the existing information, estimated that the solubility of vanadium in zirconium is less than 4.7 pct and probably less than 1.8 pct. Rostoker and Yamamoto&apos; proposed a partial diagram for the V-Zr system in a survey paper on vanadium binary alloys. Their diagram indicates the compound, V,Zr, a eutectic reaction at 1360°C, a peritectic reaction at 1740°C, and a limit of solubility of zirconium in vanadium of about 3 pct. They obtained no information on the equilibria in the zirconium-rich alloys. In view of the potential utility of the V-Zr alloys and the incomplete knowledge concerning the equilibria in the system, an attempt was made to establish the constitutional diagram. Preparation of the Alloys Raw Materials: The vanadium for making up these alloys came from the Electro Metallurgical Corp. Zirconium came from two sources. In the beginning of the investigation, sponge zirconium from the Bureau of Mines was used in making some of the alloys. Later, iodide metal made at the Westinghouse Atomic Power Development Laboratories became available. This material was used in the preparation of all the dilatometric and resistance specimens and about two-thirds of the solidus temperature specimens. A typical manufacturer&apos;s analysis of the vanadium is shown in Table I. No other analysis of the vanadium was made. The metal contained a dispersed second phase and did not have a sharp melting point. Typical results of spectrographic analysis of the Westinghouse zirconium are shown in Table 11. These data indicate a very high purity. The Bureau of Mines sponge metal was probably less pure but had good ductility. Melting: All of the alloys used in the investigation were made by melting pieces of vanadium and zirconium together in a dc electric arc furnace similar to those of Geach and Summers-Smith, craighead, Simmons, and Eastwood," and others. Melting was done in an atmosphere of helium scavenged of residual air by the preliminary melting of a separate charge of zirconium. Each ingot was turned over and melted at least three more times before removal from the furnace to aid in the attainment of homogeneity. Alloys prepared for use in the investigation are listed with the results of solidus determinations in Table III with the exception of the following compositions upon which no solidus determinations were made: 0.29, 0.54, 4.57, and 5.55 pct V. Analysis: The weight of each ingot made from iodide zirconium was within 0.1 g of the total weight of the initial charge, about 90 g. Since each component of each charge was weighed to the nearest 20 mg for amounts less than 10 g and to the nearest 0.1 g otherwise, the gross composition of an ingot could be calculated accurately. Chemical analysis for the vanadium content of several alloys agreed

Jan 1, 1956

By W. T. Hicks

The oxidation of CbO was studied by a gravimetric technique from 400° to 1200°C in oxygen. In this temperature range the oxidatiotz is characterized by an irlductive period of low oxidation rate, which becomes shorter as the temperature increases, followed by a rapid parabolic oxidation. The oxidation of CbO cannot be rate controlling in the oxidation of Cb metal in the temperature range, 800° to 1200°C. A thin optically inactive layer has been observed between the metal and Cb2O5 layer of Cb oxidized at 700°C or higher temperatures. Figs. 1(a) and 1(b) show the edge of a sample of Cb reacted to 50 pct of complete oxidation at 800°C. Fig. l(a) taken under bright field illumination shows a layer of oxide adhering to the unoxidized metal core. Fig l(b) taken under polarized light shows that this oxide layer is

Jan 1, 1962

By Stewart, J. B.

THE property at which this work was done consists of a large deposit of potash salts occurring in massive beds of rock salt, overlain by 600 ft. of salt-impregnated shales and marls. It is in the Province of Cataluiia, Spain, about 45 miles from the railway station of Mauresa and about a mile south of Suria. In addition to sinking the shaft, the program of construction work laid out by the European owners (not Spaniards) included a single-track narrow-gage railroad from Mauresa to the mine; one large office building and several large shop buildings, all of brick and concrete with steel truss roofs; two extensive benches for the future recovery plant; and a large village of stone dwellings for employees. The pay-roll showed approximately 1200 to 1500 men employed. After two years&apos; operation, ending early in the autumn of 1920, the shaft had been sunk 325 ft. and still had an equal distance to go to reach the potash; all tunnels for the railroad were done and the road-bed $0 per cent completed; only a little more than the foundations were completed for all the large buildings, and the excavations of the benches were about 75 per cent done-while only a fair start had been made upon the employees&apos; village. This was the state of affairs when the European owners decided to offer this property under a one-year option to an American syndicate, providing that they agreed to carry on the entire building program and to sink the shaft as fast as was consistent with the quality of work which they demanded, for they wished the shaft to endure at least 200 years.

Jan 1, 1926

By W. D. Roberts

INTERGRANULAR corrosion of metals and alloys has been extensively investigated and the current conclusions are summarized in the Symposium on Stress-Corrosion Cracking of Metals.&apos; It appears, however, that the relative importance of the various factors involved in the mechanism is still obscure. Several recent, independent studies, in combination with available X ray data op preferred orientation, indicate that there may be a direct correlation between relative orientation of contiguous grains and susceptibility to intergranular corrosion. The object of the present note is to show the nature

Jan 1, 1951

By Edward Martinez

Although the copper segregation process has been known as a method for treating oxide copper ores since the 1920&apos;s, the reactions involved in this process are still a matter of conjecture. However, the evidence turned up in a recent series of experiments at Asarco&apos;s Central Research Laboratories strongly indicates that some of the proposed reactions may not be occurring. Experimental work on oxide copper ores from the Sagasca mines in Chile led to the discovery of the copper segregation process in 1923. It was found that the reduction of the copper with coal at about 700°C occurred on the surface of the coal instead of remaining disseminated in the ore. The unusual behavior of the copper, which caused it to migrate from the ore particles to the coal, was traced to the presence of a small quantity of sodium chloride occurring in the ore. Further experiments with oxide copper ores proved that the presence of a halide, either occurring naturally or admixed with the ore, caused the copper to migrate from the ore particles and to segregate in the charge.

Jan 8, 1966

By W. M. Weigel

LESS advances in the technology of non-metallic minerals than for several years past mark 1931, and the cause is easily found. The universal depression and decreased markets for non-metallic as well as other mineral commodities has forced the producers to cut out all unnecessary expense and reduce operating costs to a minimum in order to keep going, even on a reduced output, and to prevent insolvency. The result. has been that but &apos;little research has been carried on, and such as has been completed has in but few cases been put into commercial practice on account of the expense involved in new equipment and plant changes. The trend in the industry has been more economic than technologic, and the greatest effort put on market studies and sales attempts to expand markets and scrutiny of present operating &apos;practice leading to reduction of cost of production. This tendency has been increased by highly competitive conditions and the buyer&apos;s market which has prevailed and to the fact that price has been a greater factor than quality in placing orders. Only in cases where improvements in technology would immediately and effectively reduce costs or where in special cases there was but little competition with almost a monopoly control has actual technical development taken place.

Jan 1, 1932

By A. F. Frederickson

Rapid advances in any branch of science often follow the development of new instruments or techniques which permit the scientist a closer look at the material in which he is interested. With the development of the polariz¬ing microscope, modern petrology was born. The resolving power of the microscope, however, was not great enough to enable the geologist to dis¬tinguish or identify the material now known to be minerals which constitute the bulk of the rocks known as "clays" and laterites. The discovery of X-rays and the development of powder X-ray diffrac¬tion techniques provided the extra resolving power necessary to get "a closer look" at the minerals in the clays and laterites. These techniques are largely responsible for the great strides made in the past two decades in the identification of the clay, sesquioxide and hydroxide minerals. To obtain an X-ray diffraction. pattern of a mineral or rock is relatively a simple procedure, but to interpret this pattern in terms of crystal structure or min¬eral identity is quite another matter. It has taken the combined talents of physicists, physical and colloid chemists, mineralogists, and geologists to unravel the identity of some of the minerals in these complex rocks and, as this symposium will indicate, many more problems remain to be solved. To assist in the identification of these minerals, we have the ever-useful microscope, which, is supplemented by the development, only in the last ten years, of differential thermal techniques and the powerful and costly "eye" that enables us to see the shapes and sizes of extremely small particles -the electron microscope. To this array of equipment must be added such gadgets as supercentrifuges, spectrographs, and the apparatus necessary for chemical analytical work. Obviously, not only is it difficult for any one man to master all of the techniques to the point where he can do competent re¬search, but also few institutions are able to provide the high capital outlay for purchase and maintenance of suitable equipment. Here we clearly see that if this equipment is to help us solve our many problems, a close co¬operation of specialists from various institutions and industry is essential. This, however, is less than half the problem. If the geologist is going to learn to intelligently find, and the industrialist to intelligently and eco¬nomically exploit the materials that constitute a large part of the mineral wealth upon which our way of life is based, we must get a better insight into

Jan 1, 1952