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By J. M. Toguri, K. Grjotheim

It is known 1,2 that the equilibrium between titanium metal, TiCl2 , and TiCl3, in a solvent of molten metal chlorides, is influenced both by the total amount of dissolved titanium and by the type of solvent. Assuming that the trivalent titanium forms the complex ion Ti111 Cl4, the equilibrium reaction may be expressed by the following equation, (Me) TiIII cl4+ 1/2 Ti = 3/2 TiII cl2+ (Me) Cl The ideal ionic equilibrium constant for this reaction is, Where the N's are the molar ionic fractions in the equilibrium melt, and (Me) the different types of cations present in the equilibrium mixture. The following thermodynamic relation is derived between Kand the concentration of cations in the equilibrium melt, mix The N"S are the equivalent ionic fractions, and so forth are constants corresponding to the standard changes in free energy for reactions in melts where only the cation indicated is present, and f (y1) is a function of the activity coefficients in the equilibrium mixture. When this term vanishes, a simplified linear relationship between In Kideal and the concentration is obtained. The simplified relationship has been applied with satisfactory results to the experimental data of Mellgren and pie,' and Kreye and Kellogg.2 MANY existing methods for the production of light metals involve the reduction of their respective metal halides in the presence of salt melts composed of alkali or alkaline earth chlorides. In such a solution phase, the light-metal halide may undergo stepwise reduction from a higher, to a lower valence, and finally to a zero valent state. In this connection, the disproportionation equilibrium is of great interest. In the case where the higher valence is three and the lower valence is two, the disproportionation equilibrium may be written as follows, 3 Me11 = 2 Me111 + Me [I] If this equilibrium occurs in a salt melt containing a large excess of alkali chlorides, a typical ionic melt is obtained. It is then possible to formulate the cation equilibrium: 2 Me+h' + Me = 3 Me++ [II] Reaction [11] is analogous to a cation exchange reaction. It has been shown thermodynamically that the equilibrium constant for such a reaction in 2

Jan 1, 1960

By N. Tiner

IN an article on magnesium and its alloys, Gann and Winston1 stated that manganese has a limited solubility in the liquid state. W. Schmidt2 showed a diagram according to Joseph Ruhrmann indicating that the solubility of manganese in liquid magnesium falls from about 2.65 per cent at 790°C. to about 0.5 per cent at 695°C. The curve was extrapolated to show zero solubility at the melting point of pure magnesium (Fig. I): This work suggested that at the lowest manganese contents it was not possible to detect either a eutectic or the formation of a solid solution, so that manganese was stated to be present in the structure as large individual crystals. Two years after the presentation of these results, Gann3 brought evidence to show that some manganese is capable of dissolving to form a solid solution, any excess of manganese present then assuming chiefly the form of small blue-gray particles scattered throughout the primary magnesium crystals, occasionally in clusters but seldom at the boundaries. He presented micrographs of cast alloys containing o.1, 0.4 and 1.0 per cent manganese that show a small amount of coring around the individual particles due to solid solution, and indicate that the location of the manganese particles is closely associated with the original dendritic structure of the primary crystallization. He also pointed out that the amount of manganese that can be dissolved in magnesium depends on the amount of other alloying elements present, the effect of the second alloying element being to decrease the amount of manganese retained in the alloy. E. Schmid and G. Siebe14 have determined the solid solubility of manganese and its variation with temperature by means of precision X-ray diffraction measurements. They found that the solubility is 3.4 per cent at 645°C and decreases to practically zero at 200°C. It is apparent that the X-ray diffraction measurements of Schmid and Siebel are not in agreement with the results of Ruhrmann as presented by Schmidt. This disagreement, and also the lack of data on magnesium-aluminum-manganese and magnesium-zinc-manganese systems, led the author to the present investigation, to determine accurately the liquid solubility of manganese and its variation with temperature. EXPERIMENTAL METHOD The experimental method for making solubility determinations consists of saturating the molten magnesium or the alloys with manganese at various temperatures and analyzing the dip samples taken from these melts. Melting is carried out in a cylindrical steel pot heated by an electric resistance furnace. The pot had a metallic outside coating to protect the steel against oxidation, and a graphite inside lining to prevent the contamination of the melt by prolonged contact with iron. The inside diameter of the pot was 4 in. and the depth 12 inches.

Jan 1, 1945

By N. Tiner

In an article on magnesium and its alloys, Gann and Winston! stated that manganese has a limited solubility in the liquid state. W. Schmidt2 showed a diagram according to Joseph Ruhrmann indicating that the solubility of manganese in liquid magnesium falls from about 2.65 per cent at 790°C. to about 0.5 per cent at 675°C. The curve was extrapolated to show zero solubility at the melting point of pure magnesium (Fig. I). This work suggested that at the lowest manganese contents it was not possible to detect either a eutectic or the formation of a solid solution, so that manganese was stated to be present in the structure as large individual crystals. Two years after the presentation of, these results, Gann3 brought evidence to show that some manganese is capable of dissolving to form a solid solution, any excess of manganese present then assuming chiefly the form of small blue-gray particles scattered throughout the primary magnesium crystals, occasionally in clusters but seldom at the boundaries. He presented micrographs of cast alloys containing 0.1, 0.4 and 1.0 per cent manganese that show a small amount of coring around the individual particles due to solid solution, and indicate that the location of the manganese particles is closely associated with the original dendritic structure of the primary crystallization. He also pointed out that the amount of manganese that can be dissolved in magnesium depends on the amount of other alloying elements present, the effect of the second alloying element being to decrease the amount of manganese retained in the alloy. E. Schmid and G. Siebe14 have determined the solid solubility of manganese and its variation with temperature by means of precision X-ray diffraction measurements. They found that the solubility is 3.4 per cent at 645°C. and decreases to practically zero at 200°C. It is apparent that the X-ray diffraction measurements of Schmid and Siebel are not in agreement with the results of Ruhrmann as presented by Schmidt. This disagreement, and also the lack of data on magnesium-aluminum-manganese and magnesium-zinc-manganese systems, led the author to the present investigation, to determine accurately the liquid solubility of manganese and its variation with temperature. Experimental Method The experimental method for making solubility determinations consists of saturating the molten magnesium or the alloys with manganese at various temperatures and analyzing the dip samples taken from these melts. Melting is carried out in a cylindrical steel pot heated by an electric resistance furnace. The pot had a metallic outside coating to protect the steel against oxidation, and a graphite inside lining to prevent the contamination of the melt by prolonged contact with iron. The inside diameter of the pot was 4 in. and the depth 12 inches.

Jan 1, 1945

By R. P. Abendroth

The hydrogen-water vapor ratio at which Fe-Cr alloy, chromium oxide, andiron chromite coexist in equilibrium was determined between 900" and 1200°C. A thermogravimetric method was used to determine equilibrium conditions. The results fit a straight-line relationship in the temperature region studied, and are given by Reduction experiments were also performed to confirm the results of the equilibrium investigation. ThE oxygen pressures at which Fe-Cr alloy, chromium oxide, and iron chromite coexist in equilibrium have been previously determined by Boericke and angert,' Morozov and Novokharski,' and Katsura and uan. Only one determination (at 1300°C) was made by Katsura and Muan, but it agrees with the results of orozov and Novokharski. The results of Boericke and Bangert, however, differ appreciably from the results of these investigators. Previous studies have assumed that the equilibrium metallic phase is pure iron, but Dahl and Van vlack have shown that the iron contains from about 1 wt pct Cr at 1000°C to over 2 wt pct above 1300°C. The chromium oxide also contains a small amount of iron in solid solution. In the present study, hydrogen-water vapor mixtures were equilibrated with the condensed phases, using a therrnogravimetric method to determine equilibrium conditions. The reaction can be written EXPERIMENTAL General Procedure. The starting material was a sintered pellet of Fe2O3-Cr2O3 solid solution with a hole in the center, and was placed on a fused silica hook. This assembly was raised into the preheated hot zone of the furnace in a helium atmosphere, hooked onto a fused silica hangdown suspended from one arm of an Ainsworth Model RV-AU-1 recording balance, and the starting weight determined. A flowing hydrogen-water vapor atmosphere was then exchanged for the helium by evacuation, and the sample reduced until the weight loss indicated the sample composition to be in the alloy-Cr2O3-chromite field. The tem- perature was adjusted incrementally until constant sample weight was achieved for several hours, to within 0.02 mg. A hydrogen-water vapor atmosphere of different composition was then admitted, and the same procedure carried out. At the end of a series of determinations, the sample was examined by X-ray diffraction to verify the presence of the desired phases. Microscopic examination of the silica hook showed no interaction with the sample, nor did it lose any weight. Several criteria were used to insure equilibrium besides constancy of weight. For a given hydrogen-water vapor composition, equilibrium was approached from both oxidizing and reducing sides by varying the furnace temperature slightly. The resulting slow weight loss or gain was observed for several hours. Constant weight could be re-established by returning to the original furnace temperature. The last criterion used was varying the relative amounts of the phases by further reduction or oxidation, and observing any changes in temperature required for constant weight for a given hydrogen-water vapor atmosphere. None were observed. This procedure was essentially the same as approaching the equilibrium from oxidizing and reducing sides, but larger weight excursions were carried out. Sample Preparation. Reagent-grade Fe2O3 and Cr83 powders were mixed in the desired proportions and heated in air at 1250°C for 2 hr. The mixture was re-ground and heated in air overnight at 1250°C. X-ray diffraction showed complete solid-solution formation as a result of this procedure. The solid solution was then pressed into l/2-in.-diam pellets using Carbowax 4000 as a binder. The hole was drilled in the center, and the pellets were sintered 24 hr at 1250°C in air on a bed of Fe2O3-Cr2O3 of the same composition, contained in an alundum boat. After cooling, the pellet surfaces were abraded with 310 paper to remove any surface compositional differences, such as loss of Cr2O3. Chemical analysis of the sintered pellets was 67.16 wt pct CrP3 and 33.02 wt pct Fe203. Atmosphere Generation and Control. The hydrogen-water vapor atmospheres were generated by passing Matheson ultrahigh-purity hydrogen, with no further purification, through two water bubblers contained in a constant-temperature water bath. Since the water-vapor dew points required in this study were below room temperature, the bath was insulated, and was cooled by thermoelectric-immersion devices. The bath temperature was controlled to 0.0l0C. Since rather high flow rates of about 900 ml per min were used through the furnace tube, an independent check of the dew point was made to insure saturation of the hydrogen by the water vapor. Although the dew point could only be determined to within 1/2"C, the determined dew points agreed with the water-bath temper-

Jan 1, 1967

By C. A. Stiles, J. W. Nyhus

Erie Mining Co. is a 10.3-million-tpy pellet producer on the east end of the Mesabi Range 60 miles north of Duluth. Its complex includes facilities for mining, crushing, grinding and beneficiation in addition to a pellet plant and power plant. A 74-mile railroad links the mine and plant to Taconite Harbor on the shore of Lake Superior. The concentrate recovery ratio at Erie is about 1: 3, and this, along with stripping activity, makes it necessary for the company to mine nearly a million tons of material a week. At the outset, all crude ore mined at Erie was hauled entirely by rail, but with expansion into additional mining areas, the company made a gradual transition towards truck-to-rail haulage. Today, in Erie's 11th year of operation, over 50% of all crude taconite mined is transported by truck to loading pockets where it is transferred to rail cars. Future years will see more taconite moved in this manner. Thus, the company has an increasing interest in tire performance.

Jan 6, 1969

By G. A. Reinhardt, H. J. Cutler

ThE Youngstown Sheet & Tube Co. has produced a large tonnage of 0.35 to 0.45 carbon forging steel, the acceptance of which was based on the physical properties of test specimens obtained by forging the original 5 3/4-in. (14.5 cm.) square bloom to a 3/4-in. (1.9 cm.) round. Annealed and tempered specimens were required. The test bars were annealed by heating from 900" to 950' C. and cooling slowly in mica. The test bars were tempered by heating to 825' to 875" C., quenching in water, and drawing to 515" to 535" C. Immediately after heat treatment, the test pieces were machined to a diameter of 0.534 in. (1.38 cm.) and tested. Very good physical properties were obtained and no difficulty was experienced in meeting the specifications called for. UlTimate Strength.. Elongation, Lb. pER Sq. In. PEE Cent.. in 4 In. Not LeEs Than Annealed specimens.............. 78,230 to 92,450. 18 Tempered...................... 120,000 to 149,350 9 After experience on this material, production of slightly higher carbon forging steel was started. The method of testing this material required that test blooms be either normalized or annealed. The normalizing consisted in heating to 850" to 900" C. and cooling in still air; the annealing, in heating to 850" to 900" C. and cooling in the furnace or in mica. From the treated bloom, the test pieces were taken either by core drilling or by sawing from points midway between the edges and the intersection of the diagonals. The cores or blocks were turned to a standard 2-in. test piece with a diameter of 0.564 in. and tested without further treatment. The physical requirements of the test pieces were: yield point, pounds per square inch minimum, 44,800; ultimate strength, pounds per square inch, 89,600 to 112,000; elongation, per cent. in 2 in. not less than 17. Difficulty was encountered as soon as work on this material was started. Many precautions and refinements were instituted but it was found very difficult to secure the required elongation.

Jan 1, 1920

By W. Klement

By quenching liquid alloys, single-phase solid solutions are obtained in the ranges 0 to 42.0 at. pct Co-Au and 0 to 15 and 75 to about 100 at. pet Co-Cu. Metastable solid solutions are also found in multiphase 42.0 to 49.0 and 69. 0 to about 100 at. pet Co-Au alloys. fie inability to achieve complete solid solubiliiies in Au-co and cu-co alloys is rationalized by a conszderation of the rate processes during cooling and solidification. Trends in lattice distortion and shifts in the compositions of the melting-point minima and critical points are discussed for the binary alloys of copper, silver, and gold with some of the transition metals of the first long period. By rapidly cooling alloys from the melt, a continuous series of metastable solid solutions can often be obtained for components of similar crystal structure which normally form eutectic systems.' The eutectic system Au-Co, Fig. 1, and the peritectic system Cu-Co, Fig. 2, were investigated in order to determine the extent of the metastable solid solutions attainable with the present technique.* EXPERIMENTAL PROCEDURES Most of the alloys were prepared by melting weighed quantities of the elements (purity greater than 99.9 pct) under hydrogen in alumina crucibles by means of induction heating. After reweighing, the alloys were cast under argon into 1 mm diam wires. However, it was not possible to prepare some of the Cu-Co alloys with the requisite homogeneity (over about 1 mm3) in this way. For these alloys, reduced powders (purity greater than 99.9 pct) were mixed for 12 to 48 hr, pressed into compacts that were sintered at 1000º to 1050°C for 6 to 48 hr under hydrogen, and then furnace-cooled. Alloy charges of a few mm3, cut from the cast wires or chipped from the sintered compacts, were heated to 1550º to 1600°C in 30 sec in an alumina insert held within a graphite support and then ejected by a pulse of helium onto a lightly polished copper strip on the inner periphery of a rotating wheel. The

Jan 1, 1963

By L. D. Jaffe

IN previous metallographic work on titanium and its alloys, difficulty has been encountered in distinguishing spheroidal particles of titanium hydride, dispersed in a-titanium, from other phases that may be present, such as p-titanium. This problem is common in examination of commercial unalloyed titanium.' In the course of an investigation of the Ti-H phase diagram, it was noted that titanium hydride, dispersed in a matrix of a-titanium, showed strong optical anisotropy when examined under polarized light. With sensitive tint illumination, particles of the hydride, when the stage is rotated, changed from bright yellow to bright blue in color. Since P-titanium is cubic, it showed no color change on rotation, remaining dark gray or blue-gray. Although a-titanium is hexagonal, it showed only a minor color change, going from pale pinkish-blue to pale purplish-blue. These colors could be modified somewhat by adjustment of the illumination. They were observed in specimens mechanically polished, both without etching and after etching with hydrofluoric acid-nitric acid mixtures in either water or glycerine. The strong color change of the hydride seems to offer a simple method for its metallographic identification. Optical anisotropy of titanium hydride is inconsistent with its accepted face-centered-cubic structure.' Samples of iodide titanium containing 6 to 40 atomic pct deuterium were prepared for diffraction studies. After deuterating and slow cooling' the samples were held 21 % hr at 400 °C, water quenched, held 61 hr at 100°C and quenched, then held 64% hr at 255 C and quenched. Debye ex-posures with MoKa X-rays and 1.111A neutrons were made at room temperature of samples as-deuterated and after the 100" and 255°C treatments. Table I shows the lines observed, in addition to those attributable to a-titanium. These data show that the hydride phase was not cubic, but probably tetragonal. The titanium atoms appeared to form a body-centered-tetragonal lattice complex, two titanium atoms per cell, with approximate dimensions: a = 3.12A, c = 4.18A, and c/a =1.34A. This is equivalent to a face-centered-tetragonal complex, four titanium atoms per cell, with approximate dimensions: a = 4.42A, c = 4.18A, and c/a - 0.946A. The presence of the 2.98 and 1.81A neutron lines indicates that the true Bravais lattice is not identical with this lattice complex, but may be primitive tetragonal with dimensions some multiple of those of the complex. The relative intensities of the hydride and a-titanium X-ray lines as functions of overall composition indicated that the hydride, presumably in equilibrium with the a at 100" to 255"C, contained more than 62 atomic pct H. Acknowledgments The experimental work covered in this report was done at Brookhaven National Laboratory, through the courtesy of D. Gurinsky. The cooperation of J. Sadofsky, 0. Kammerer, A. McReynolds, and A. Cendrowski is gratefully acknowledged.

Jan 1, 1957

By George Harrington

THIS paper is a brief description of the design and equipment of a new coal mine in southern Illinois, which has many features not common practice in shaft coal mining and which is laid out and equipped for such unusually large capacity that it promises soon to become one of the largest mining operations of its kind. Shaft sinking for the mine, New Orient, was commenced in May, 1921, by the Chicago, Wilmington & Franklin Coal Co. In October, 1924, the plant was practically completed and was producing over 6000 tons of coal per day. There is good prospect that within a few years, when the mine is fully developed and manned, the output will attain a daily rate of 12,000 tons. The coal seam at New Orient lies approximately horizontal, about 500 ft. below the surface, and may be said to run from 9 to 12 ft. in thickness. The tendency in Franklin County has been toward large mining units (5000 to 6000 tons per day) with great care being given to protection against fire and explosion hazards, and usually with quite elaborate surface plants permitting careful preparation of the coal into graded sizes comparable with those made in the anthracite region. The field is unionized, with uniform conditions of wages for various classes of work, hours, etc., and the Illinois mining laws are quite specific with regard to fireproofing and safety measures. These conditions make it difficult for any but well-equipped and well-operated mines to meet the competition of the numerous fine properties of which this county can justly be proud. The coal company's property was already developed on the western side by the Orient. mine-a much visited and written about operation (with which many of you are possibly familiar through the Department of Mines' film "The Story of Coal ") which until recently held the 8-hr. production record with 8218 tons and usually ran quite consistently with production of slightly over 6000 tons per day. Experience at Orient was naturally one of the greatest influences in determining the location and character of the New Orient.

Jan 2, 1925

. F. W. SPERR, JR.,* Pittsburgh, Pa.--Mr. Malcolmson states that the Carbocoal process produces ammonium sulfate in excess of that normally recovered in the ordinary byproduct coke process. Table 3 indicates that 20,000 to 25,000 lb. of sulfate of ammonia are obtained in carbonizing 1000 tons of Clinchfield coal. This is a high-grade coal and yields from 26 to 28 lb. of ammonium sulfate per ton in a modern byproduct coke oven. On the next page, 21 lb. is stated as the yield of ammonium sulfate per short ton of raw coal; this is less than the average production from any well operated byproduct coke-oven plant treating coal of the character usually coked, in Pennsylvania and Ohio. The statement as to the comparative yields of light oil is somewhat misleading in view of the results obtained during the past year or two by the more modern byproduct coke plants. The plants put in operation by the H. Koppers Co., during the past two years, are producing about 3.5 gal. of light oil per short ton of coal, and several of these plants are producing more than 4 gal. per ton. The yield of pure toluene runs from 0.45 gal. to 0.55 gal. per ton. .The quality of the light oil .obtained from the Carbocoal process is of much greater importance than would be inferred by one not closely familiar with the subject. The presence of paraffins in the benzol and toluol fractions seriously detracts from their commercial value; the benzol and toluol fractions derived fro in the Carbocoal process contain about 50 per cent, of paraffins. It should be thoroughly understood what these paraffins are. They are simply hydrocarbons that go to make up ordinary petroleum, and if a successful method for the removal of paraffins from benzol and toluol has been developed, this can at once be applied to several well known processes by which benzol and toluol can be made directly from petroleum, which have as yet been total failures on account of the contamination of these products by paraffins.

Jan 11, 1918

By J. P. Neumann, L. Raymond

At temperatures near 1000°C, only the (112) (111) slip systems are operatire in tungsten. Therefore, the substructure introduced into the billet upon rleforming a single crystal by rolling at 1000 "C can be controlled by proper selection 01. processing ral'iubles. Using a reduction of 10 pct pel- pass, the (001)[110] and the (110)[001] crystals will deform by duplex slip rip to a 50 pet reduction in thickuess. These rolled single-crystal sheels are characlerized by anisotropic hardening, retention of ductility with warm working, lattice bending which is related to the conlacl (angle, and macroscopic dimensional changecs in the length bid not the width of the billet. When several slip systems become operative, a greater degree of work hardening is itztvoducetl into the crystal. This rolling- condition is characlerized by isotropic hardening, loss of ductilily with warm working, complex lattice distortions, and macro-scopic dimensional changes in both the length rind Width of the billel. IN tungsten, the {1 10}(111) slip systems are operative below room temperature,' while above 700°C only the {112{ (111) slip systems are observed.2,3 In the transition region, i.e., room temperature. both systems appear. It is the purpose of this investigation to show that tungsten single crystals deformed by rolling at a temperature where only one slip system is operative generate dislocation substructure which depends on the crystal orientation. For a specific crystal orientation. the resulting dislocation substructure can be further influenced by modifying the rolling procedure. Crystals oriented for multiple slip display less substructural sensi- tivity to modifications in processing techniques than do single crystals oriented for duplex slip. Under simple slip modes of deformation, very little work hardening is introduced into a rolled single-crystal sheet. Mechanical properties such as room-temperature strength. ductility, and hardness are used to confirm the existence of the different work-hardened conditions generated within the crystal by modified warm-rolling techniques. EXPERIMENTAL PROCEDURE Material. Single-crystal billets of four different crystal orientations. grown by the Arc-Verneuil technique. were ground to a size of 0.25 by 0.375 by 3 in. In terms of their rolling plane and rolling direction, the billets had the following orientations: (1101 [001 ] (110) [110] (001) [110] (001) [100] The actual orientation of all crystals was within 5 deg of the ideal orientations. The typical impurity content of the crystals is given in Table I. Polishing and Etching. Polishing was done elec-trolytically in a 20 g per liter aqueous solution of NaOH at approximately 10 v. It was established by the Laue back-reflection X-ray technique that the surface damage due to grinding and cutting operations with a diamond wheel did not exceed 0.001 in. Therefore after each cutting or grinding operation at least 0.002 in. was removed electrolytically from the surface in order to eliminate surface effects. By lowering the voltage to 3 v, subgrain boundaries and individual dislocations are identified in agreement with Berlec 4 where the etch-pit traces on a cubic plane form a square. The etching time was about 5 sec at room temperature. Rolling. Rolling was carried out on a Loma 2-high mill (Model 600). The peripheral velocity of the 6-in.-diameter rolls was 500 in. per min, with the surface temperature of the rolls about 400° to 450° C The billets were heated before each pass for 30 min in argon to 1000 C. Oxidation of the crystals during rolling in air resulted in a thin layer of greenish-yellow WO 3 This oxide was removed after each pass by immersing the crystals for a few minutes in a boiling NaOH solution. Prior to the initial rolling pass, a surface layer of 0.001 in. was removed by polishing. The crystals were then annealed in vacuum (10-4 torr) at 2400 C for 30 min. All crystals were rolled in the same direction; i.e., the same end was always introduced into the rolls. The rolling program was conducted in

Jan 1, 1965

By W. L. Chen

The Batac jig was first introduced in the US for fine coal cleaning in 1973 (Tackett, 1977; Hake, 1976). Since then, a total of six such jigs of various sizes have been installed in five US plants for a total capacity of 2346 t/h. The raw coal size ranges from 19 mm x 0 to 9.5 mm x 0-fraction sizes previously fed to heavy medium cyclones, Deister tables, or water only cyclones. Growing interest in the Batac jig as a replacement for the above equipment is due to the following reasons: • Unlike heavy medium cyclones, no magnetite is required. As a result, the operating cost of the plant is reduced. • The compactness of equipment is unique on a unit ton per hour basis as compared to other equipment. • Solid state electronic control of jig stroke length, frequency, and jig bed depth makes the equipment highly efficient. Installations of Batac jigs in the US as of June 1980 are shown in [Table 1]. Use of the Batac jig is even greater outside the US (Anonymous, 1980; Chen, 1980). Its use is not limited to fine coal but is applied to coarse coal as well, with 102 mm size in the feed (Zimmerman, 1975). In countries where consumption of magnetite associated with the heavy medium system of coal cleaning is considered a waste of iron ore resource, the Batac jig is regarded as the primary choice in the selection of cleaning equipment (Chen, 1980).

Jan 1, 1981

By R. Stefanko, Y. J. Wang, H. R. Hardy, R. Y. Kim

Since 1964, the Dept. of Mining at The Pennsylvania State University has been carrying out extensive studies associated with the phenomena of microseismic activity and inelastic behavior in geologic materials. Briefly, the program to date has involved the following stages 1) Study of the microseismic noise and energy rates for selected geologic materials under incremental, uniaxial tension.1,2 2) Investigation of the frequency spectra of microseismic activity of selected geologic materials under incremental, uniaxial tension.3,4 3) Investigation of the time-dependent inelastic deformation of geologic materials and the analysis of such deformation in terms of mechanical models.5, 6 4) Simultaneous study of microseismic activity and time-dependent inelastic deformation in geologic materials under incremental, uniaxial compression.7,8 Details of the research involved in stage 4 of the program constitute the subject of this chapter. It should be noted that the majority of the experimental data quoted in this chapter forms part of a thesis to be presented by one of the authors (Kim) in partial fulfillment of the requirements for the Ph.D. degree in mining engineering at The Pennsylvania State University. During the last two or three years, a number of important papers have been published which deal primarily with the fundamental structure and mechanical behavior of geologic materials. Recent papers 9,10 have provided research workers in the rock mechanics field with a meaningful overall picture of rock as a structural material. The concept that many

Jan 1, 1970

By H. E. Hawkes, D. A. Barr

Time variations in the copper content of the sediments of streams draining mineralized areas were studied in two areas of contrasting climatic environment, one in northern and one in southern British Columbia. In each area, samples were collected and observations made of rainfall, stream discharge and air and water temperature at intervals throughout the summer season. Samples were analyzed for total and cold-extractable copper. Results showed a weak inverse relation between cold-extractable copper and discharge in two out of the three test sites in the southern area, and a decrease in ratio of COld-extractable to total copper over the duration of the test period at a highly anomalous site in the northern area. In suspended rock flour resulting from glacial erosion of mineralized rock in the northern area, virtually all the copper was found to be soluble in cold, dilute hydrochloric acid. None of the variations observed is sufficient to cause serious problems in geochemical sediment surveys. Systematic collection and trace analysis of stream sediments has seen wide application in recent years as a method of primary prospecting in primitive areas. Common practice is to collect fine-grained samples of sediment either from the active channel or from the flood plain near the channel. Samples are dried, sieved and the -80-mesh fraction analyzed after breakdown of the sample by a relatively strong attack, such as by fusion or by treatment with hot perchloric acid. Drying, sieving and rigorous chemical attack requires established facilities, either in a well equipped central laboratory or in base camp. Thus analysis for total metal involves a substantial delay from the time the samples are collected until the analytical data can be reported. An alternative system uses a cold aqueous extrac-tant in place of the hot acid or flux.4 Advantages of the cold-extraction techniques are that kits can be prepared for use directly at the sample site and that, in some problems, the patterns in cold-extractable metal, usually abbreviated cxMe, are more useful as ore guides than the patterns in total metal.' In the course of operational geochemical sediment surveys, a problem that has come up repeatedly is failure to reproduce anomalous values or patterns by resampling the same areas. The mystery of the vanishing anomaly has led to speculation as to whether there is a significant variation in the metal content of sediment samples with the weather or with the time of year. Review of the published literature shows that a number of experiments have been carried out on time variations in the metal content of stream water.1,2,5,7-9 The only published report on time variations in stream sediments that has come to the authors' attention, however, is by Govett,3 working in Northern Rhodesia.

Jan 1, 1963

By H. T. Kennedy, S. G. Dardaganian, J. L. Clanton

This paper presents equilibrium ratios measured on oil and gas samples taken from the Kelly-Snyder field at the reservoir temperature of 128°F. From these data smoothed curves were constructed for the reservoir fluid up to the bubble-point, 1,874 psia. A material balance calculation, based on the use of equilibrium ratios instead of the usual solubility and shrinkage meayr~rements is made on the field and compared to the con\.entional method. DETERMINATION OF EQUILIBRIUM RATIOS The equilibrium ratios, or K values were obtained by recombining separator samples of oil and gas taken when the reservoir was above its bubble point, and thus represented the reservoir fluid before any change had occurred due to the evolution of gas. The well sampled had a gas-oil ratio of 617 cu ft of high pressure sepalator gas per barrel of separator oil. and a bottom-hole temperature of 128°F. Samples were brought to equilibrium by agitating for 24 hours in a thermostat, maintained at the proper temperature within 0.2ºF, mercury being added when necessary to maintain the pressure constant. Samples of oil and gas were then taken by constant pressure displacement, and analyzed by low temperature frac-tionation. Equilibrium ratios were determined at 128°F and 500, 800, 1,000 and 1,400 psig. At the latter pressure, there were indications that the gas samples were contaminated with small quantities of oil, and only data taken at the first three pressures were included in Fig. I. This figure has been extended to higher and lower pressures by the use of the Fluor charts for 3,000 psi convergence pressure, on which the experimental points fit well. MATERIAL BALANCE EQUATIONS The possible errors involved in conventional material balance equations have been analyzed by Muskat1. Where the errors occur in field measurements, or in obtaining effective averages from variables such as gas-oil ratio and pressure, they will evidently be involved in any attempt to estimate the content of the reservoir. On the other hand, substantial errors may be introduced in conventional material balance calculations by: (1) the neglect of the amount of oil dissolved in gas at high pressures and temperatures in the reservoir, but which condenses under separator conditions; (2) the assumption that the separation of oil and gas in the reservoir may be duplicated by a differential liberation in the

By I. S. Levy, J. L. Brimhall, B. Mastel

Specimens of' Hastelloy X-280, a low-cobalt version of the solid-solution- hardened nickel-base alloy Hastelloy X, were given a series of thermomechanical treatttzents. They were then Lensile-tested at room temperature and 1350°F. The Microstructures of the specimens tested at 1350°F were studied by electron Microscopy. Microscopy showed that dislocation tangling, caused by the cold working, mas still in evidence after aging-for 24 hr to temperatures as high as 1550oF. (Cr, Mo)23 C6, (Fe, Mo)6 C'. as well us an unidentifiable phase precipitale due to the combination of the thermomechanical treatments and subsequent tensile strain. The room -temperature and 1350°F tensile properties show a general increase ill strength and decreccse in ductility with increusing cold-work level. This is due to the dislocation taangling-. PerLurbatiot~s to this general trend occur- due to solid-solution weakening at the higher cold-work levels as a direct result of the preciplitation reactions. THE requirements for corrosion resistance and high-temperature strength place nickel-base alloys among the more promising materials for advanced nuclear reactor applications. However, when these alloys are irradiated at service temperatures, they generally suffer severe embrittlement'" and reduction in rupture life.3 Certain experimental treatments resulted in improvements in the tensile and stress-rupture properties of Hastelloy X-280, a solution-hardened nickel-base alloy.' To provide a basis for understanding these improvements, unirradiated tensile specimens were examined by electron microscopy. The results are reported in this paper. EXPERIMENTAL DETAILS Material. Hastelloy X-280, a low-cobalt version of Hastelloy X, is a member of the solution-hardened class of nickel-base alloys. The Hastelloy X-280 was obtained from 4- and 1-in: thick plates in the mill -annealed condition. Table I gives the chemical composition of the material as reported by the National Spectrographic Laboratories. ~x~erimental Treatments. Plates of suitable size, 12 by 3 by 1 in., or by + in., were cut under a water jet from the stock material and examined ultrasonic -ally for homogeneity of grain size and absence of voids. The acceptable plates were solution-treated at 2150°Ffor 1 hr and air-cooled. These plates were then reduced in thickness by cold rolling 0, 10, 15: or 20 pct along the original rolling direction. The plates were machined into buttonhead tensile specimens with a gage diameter of 0.125 in., with a gage length of 1.125 in., and with their tensile axes parallel to the rolling direction. The specimens were examined for quality of finish with a penetrant dye, ultra son ically checked for voids, and finally given a dimensional tolerance check with an optical comparator. The acceptable specimens were aged for 24 hr at either 1000" or 1500 F and air-cooled. These specimens were then held at 540°F in a water loop for approximately 18 days to qualify as controls for similar specimens irradiated under the same conditions of time, temperature, water chemistry, and flow rate. Table U summarizes the treatments. These treatments were investigated to establish whether prior precipitation and stabilization of carbide phases at strain sites within the matrix could reduce the amount of carbides available for precipitation at grain boundaries during service. Tensile-Test Conditions. Specimens were tested to fracture at room temperature or 1350 F in air on an Instron tensile-testing machine at a crosshead speed of 0.05 in. per min. The time for the furnace to reach equilibrium at 1350°F was approximately 30 min; soak time prior to testing was 15 min; and test duration was approximately 5 min.

Jan 1, 1968

By Rodney L. Stone, David S. Cahn

As part of an over-all laboratory and plant test program to determine mixing ad other techniques for a more economic use of bentonite as an iron ore pellet binder, a settling test for measuring the bentonite content within a pellet or a batch of pellets has been developed. Through this test, it has been shown that dry fracture load is directly proportional to bentonite content in batches of pellets, but inversely propor tional to bentonite content in individual pellets of the same batch. This apparent paradox is explained by a negative correlation between a pellet's size and its bentonite content and the fact that large pellets can withstand a higher fracture load than small pellets. In past attempts to characterize green and dry iron ore pellets, the authors found large variations in the results of strength tests on closely sized pellets from the same batch.' Reasons advanced for such variations in the quality of pellets in which the binder is bentonite were the presence of internal flaws and the nonuniform distribution of the binder. Even when resulting pellet strength is good, there is still the question of whether the same strength could have been attained through a more effective use of a smaller amount of bentonite. The authors' own and other studies 2-3 have pointed out the strong dependence of pellet strength on the degree of "mixedness" of the iron ore concentrate and the bentonite binder. However, before such a relationship could serve as a guide for the development of better mixing techniques and the associated economy of

Jan 1, 1969

By Wm. C. Madge, H. P. Allen

The chloridizing mill of the Standard Reduction Co. is located about 75 miles south of Salt Lake City on the Tintic branch of the Denver & Rio Grande Western R. R. and 12 miles from the Tintic Standard mine. The daily capacity is 200 toss of a siliceous, low-grade, silver-lead ore from this property. It has operated continuously since it was started in January, 1921. The process consists essentially of a chloridizing roast followed by a percolating leach with a nearly saturated solution of common salt, acidified with sulfuric acid, the precipitation of silver on sponge copper and of copper and lead on tin-plate cuttings. The precipitates are shipped to a smelter. Some of the general ideas involved are said to have been used by Augustin in England, in 1840. A number of textbooks treat of the subject, especially the chloridizing roast followed by a leach with sodium hyposulfite or amalgamation. The process was revived in this district by Theo. P. Holt, N. C. Christensen, the Bureau of Mines, and others. Nature of Ore Treated The average assay of the ore treated during 1924 is as follows: Gold, ounces per ton...................................... 0.025 Silver, ounces per ton..................................... 18.26 Copper, per cent......................................... 0.30 Lead, per cent........................................... 5.00 Silica, per cent........................................... 65.00 Iron, per cent............................................ 10.00 Lime, per cent........................................... 0.70 Sulfur, per cent.......................................... 3.00 Arsenic, per cent......................................... 0.70 The silver is finely disseminated and occurs as native, combined as a sulfide and, to a very small extent, as the chloride. The lead may be present as carbonate, sulfide, or sulfate.

Jan 1, 1926

By W. V. Long, D. H. Reynolds, R. B. Bhappu

Equilibrium distribution coefficients were determined for some monovalent and polyvalent ions for several absorbing and exchanging media as functions of pH and initial ion concentration. Among ions studied were NH4 (I), K(I), Ni(II), Ce(III), Th(IV), and Mo(VI). Absorbents used were: ion exchange resins; a tertiary, and a quaternary amine in an inert solvent; and some activated carbons. The ions studied were in aqueous HCI, HNO3, H2SO4, or HC104 solutions. The classical mass action expression proved of little value in describing the variations observed. The data indicate that the determining factors in absorption and ion exchange may be the ionic species in the aqueous solution, which in turn depend upon pH, dilution, and perhaps other conditions. Three sorption processes have become prominent in recovering values from leach solutions. These are: 1) ion exchange, 2) solvent extraction (liquid ion exchange), and 3) physical adsorption by materials of high specific surface. In the first two of these processes the exchange reaction is considered chemical in nature, and is discussed in terms of the mass action principle. The third is considered a surface phenomenon and is discussed in terms of surface areas and various forms (Gouy, Stern, Grahame, etc.) of the Helmholtz double-layer theory. Generally speaking, we have found in chemical analysis and hydrometallurgical studies that there are close similarities between the three sorption processes, and also differences which are difficult to reconcile with any of the usual theoretical treatments. That others have experienced the same troubles is shown by the fact that usable processes, in chemical analysis as well as in hydrometallurgy, generally are discovered by empirical procedures. EXPERIMENTAL CONSlDERATlONS The gaps between theory and practice have allowed many conflicting statements to appear in the litera- ture. To learn, in particular, the behavior of some metallic ions on a cation exchange resin at a constant pH, equilibration studies were made over a wide range of concentrations.' Results are shown in Fig. 1 for four metals in hydrochloric acid solution on a strongly acidic cation exchange resin, AG 50W-X8 (Bio-Rad). The distribution coefficient, defined as D = amount of metal extracted per g of resin/amount of metal unextracted per ml of solution is seen to vary in a way to support all manner of reports about its behavior with changes in solution concentration. The metals used were chosen from those least likely to form stable chloro-complexes. The changes of slope in the various isotherms may reflect formation of unsuspected chloro-complexes of low stability (ion-pairing for example) whose concen-

Jan 1, 1967

By Harold Margolin, W. R. Hibbard, R. W. Fenn, H. P. Moore

Deformation lines, also called etch markings or strain markings, are non-effaceable lines developed in individual grains by etching a metal specimen which has been cold worked sufficiently to cause atomic non-conformity or slight orientation differences within the grains. Etching occurs more rapidly at these lines of high chemical reactivity to produce a result similar to that revealing grain boundaries. Wider etching effects forming bands have been found. They are believed to be bands of deformation lines which form areas of measurably different orientation from the crystal matrix. The crystallite rotations causing these bands have been shown by Barrett2 to contribute to deformation textures. Although deformation lines have been observed in many metals, the amount of deformation requireti for their appearance has been established only in general terms. Mathewson and Phillips3 observed the first appearance of deformation lines in cold-rolled alpha brass at about 20 pct reduction in thickness using the standard ammonium hydroxide hydrogen peroxide etchant. Price and Davidson4 noted defor- mation lines in common high brass after 26.5 pct reduction by cold rolling using the same etchant. Johnson6 observed dark thick forklike lines in 99.99 pct pure copper reduced 31.8 pct. Adcock6 observed deformation lines in 80-20 copper-nickel alloy rolled 50 pct. Samans7 found no deformation lines in alpha brass single crystals cold rolled 9.5 pct but they did appear after 25 pct reduction using ammonium hydroxide and hydrogen peroxide etchant. Barrett and Levenson8 observed deformation bands in drawn polycrystalline iron at very small reductions in area and noted that their initial appearance perhaps depends on grain size and other conditions. They reported deformation bands in a single crystal of iron reduced 6 pct by drawing. Brickg noted that deformation lines in 70-30 brass apparently associated with I I I I ) planes appeared after reductions of from 20-50 pct by cold rolling. Brick and Williamson10 noted that in single crystals of 70-30 alpha brass "as in polycrystalline brass, no deformation markings appeared until reductions exceeded 20 pct." Cook and Richards" reported that in Copper cold rolled less than about 50 Pet few strain markings were apparent but for higher reductions many strain markings appeared transverse to the rolled direction. In a review article Brick and Phillips12 noted that previous studies had not shown deformation lines in cold rolled alpha brass below 20 pet reduction and added that 4

Jan 1, 1949