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By R. D. Daniels, T. G. Oakwood

A study was made of the effects of small quantities of hydrogen on the mechanical properties of colum-bium. Tensile specimens, hydrogenated to concentrations of 20 to 200 ppm, were tested at temperatures of 300°, 191°, and 77°K. Although hydrogen was found to have little effect on the strength of columbium, the ductility of Cb-H alloys was found to be quite sensitive to both hydrogen concentration and temperature. At 300°K, an abrupt loss in ductility occurred at a critical hydrogen concentration, although some ductility was observed beyond the tolerance limit. A similar result was found at a lower hydrogen concentration at 191°K. At 77°K, however, a more gradual loss in ductility with increasing hydrogen concentration was observed. Hydrogenated columbium was thus observed to undergo a ductile-brittle-ductile transition. Metallographic examination of fractured specimens revealed extensive porosity at both 77° and300°K which was a distinct function of hydrogen content. At 191°K, although some secondary cracking was noted, the amount of observed porosity was minimal. These observations are interpreted in terms of hydrogen solubility and mobility as a function of temperature and in the role of hydrogen in promoting growth of microcracks. lHE effect of hydrogen on the mechanical properties of the refractory metals is not, at present, completely understood. A number of studies have shown these materials to be susceptible to hydrogen embrittlement. Roberts and Rogers1 have found that vanadium can be embrittled by hydrogen. It was further demonstrated that fracture undergoes a ductile-brittle-ductile transition as the temperature is lowered from 150° to -196°C; i.e., there is a ductility minimum observed at a certain temperature. The ductility is increased by either raising or lowering the temperature from this point. A more complete study by Eustice and Carlson2 on vanadium containing 10 to 800 ppm placed the ductility minimum at about -100°C with variations reportedly due to hydrogen content and strain rate. Ductility minima have also been found at certain temperatures for tantalum containing 7 ppm H3 and 140 ppm H.4 At hydrogen concentrations above 270 ppm, however, the ductility return at low temperatures was considerably reduced.4 In the case of columbium, some disagreement exists in the literature. Eustice and Carlson,5 Wilcox et al.,6 and Imgram et al.4 failed to find a ductility minimum although a composition-dependent ductile-brittle transition was observed. Hydrogen concentrations in these investigations were 20 ppm,5 1 to 30 ppm,6 and 200 to 390 ppm.4 However, Wood and Daniels7 observed a rather pronounced ductility minimum at hydrogen contents ranging from 19 to 252 ppm. Those theories of hydrogen embrittlement involving the precipitation of diatomic hydrogen which have been applies to ferrous metals8-12 do not seem to be applicable to the case of columbium and other exothermic occluders. Such theories propose that extensive crack formation and propagation occurs by the precipitation and expansion of diatomic hydrogen at internal voids and microcracks. However, photomicrographs of hydrogenated columbium do not show any evidence of damage introduced by the sorption and precipitation of diatomic hydrogen; rather, at high hydrogen concentrations, a hydrogen-rich second phase is precipitated.13'14 In addition, a number of these theories require the development of high hydrogen pressures at voids in the structure.8'10'12 This does not appear to be feasible in the concentration ranges discussed in the aforementioned paragraphs. The possible interaction of atomic hydrogen with microcracks resulting from dislocation pile-ups15,16 remains in doubt since pile-ups have not been observed in bcc metals17 including columbium.18 Wood and Daniels7 have put forth the possibility that a hydride precipitation could be responsible for crack nucleation in columbium. Work by Longson19 has shown that hydrogen embrittlement of columbium parallels the bulk solubility limit; i.e., as the solubility increases, for instance with temperature, the amount of hydrogen necessary to cause embrittlement also increases. Although a hydride precipitation appears attractive as a means of nucleating microcracks in columbium, what require more intensive study are the low-temperature anomalies which have been observed, i.e., the ductile-brittle-d'ictile transition characteristics. Also, the hydrogen concentrations where embrittlement occurs are often below the bulk solubility limits determined by Albrecht et al.13,14 and Walter and Chandler.20 This work is an attempt to determine more definitively the effects of concentration and temperature on the mechanical properties of dilute Cb-H alloys. EXPERIMENTAL PROCEDURE Ultrahigh-purity columbium rods, obtained from the Wah Chang Corp., were cold-reduced by rotary swaging. A chemical analysis is given in Table I. The material was cut into cylindrical blanks 1.50 ±0.005 in. long. Individual specimens were either given a stress relief anneal at 750°C or recrystal-lized at 1200°C. Resulting microstructures were either a "bamboo" structure characteristic of a wrought material or a recrystallized structure with a grain diameter of approximately 100 n. All heat treatments were carried out in a vacuum of 10-5 Torr or less.

Jan 1, 1969

By W. H. Basssett

THE amount of oxygen present in refined copper bears an important relation to the effects of various impurities on physical properties of copper, as well as the effects of reducing gases at higher temperatures. It seems fitting at this time, when the effects of reducing gases on copper are being discussed, to describe methods that have proved satisfactory for the determination of oxygen and sulfur, and to present some results obtained by investigation of these methods in the authors' laboratory. The procedure for the determination of sulfur is closely interrelated with that for oxygen and has, therefore, been included. It was first proposed by Hamper that oxides in copper could be accurately determined by the loss in weight sustained by finely divided copper when reduced at red heat in pure hydrogen, or by the weight of water produced. Hampe's method was later modified by Archbutt,2 who established the accuracy of the method and demonstrated that equally accurate results were obtained by noting the loss in weight or by weighing the water formed. The determination of oxygen by heating in carbon monoxide has been proposed by West.3 In our hands this method has given slightly lower results than obtained by heating in hydrogen.

Jan 2, 1926

By C. A. Winkler, V. Hospadaruk

PREVIOUS papers from this laboratory have discussed the effect of chloride ion on the cathode polarization during electrodeposition of copper from copper sulphate-sulphuric acid electrolytes, in the presence and absence of gelatin. The steady state polarization'" was found to decrease sharply and pass through a minimum with increasing chloride ion concentration in the presence of gelatin. The minimum shifted to higher chloride ion concentrations and to higher polarization values with increase in current density or gelatin concentration, while an increase of temperature shifted the minimum toward lower halide concentrations and lower polarizations. Since these observations were made in acid-copper sulphate electrolytes that contained no other addend than gelatin, there was obviously the possibility that they were not applicable to deposition of copper from commercial electrolytes that contain a variety of other substances in relatively small amounts. In particular, it was of interest to determine whether the presence of arsenic, antimony, or bismuth in the electrolyte would materially alter the behavior. Experiments have now been made under a variety of conditions with systems containing these cations, and the results are summarized in the present paper. Experimental Polarization measurements were made at 24.5oC in a Haring cell in the manner described previously.' Electrolytes were made with doubly-distilled water, and contained 125 g per liter of copper sulphate and 100 g per liter sulphuric acid, both of reagent grade Eimer and Amend gelatin from a single stock was used throughout. Chloride ion was introduced as reagent grade sodium chloride, and arsenic, antimony, and bismuth by dissolving the chemically pure metal in hot concentrated sulphuric acid and adding appropriate amounts of the solutions to the electrolyte. Each cathode, of 1/16-in. thick rolled copper, was first etched in 40 pct nitric acid and washed thoroughly with distilled water. The surface was then brought to a standard condition4~9 by electrodeposition from an acid-copper sulphate electrolyte containing no gelatin, at a current density of 3 amp per sq dm for 30 min, followed by deposition at a current density of 2 amp per sq dm for l hr. As in previous studies, the cathode polarization eventually attained a steady-state value (15 to 75 min) such that further change in polarization did not exceed 0.2 mv per min. The polarization values recorded are those for the steady states. "Excess weights" were determined with arsenic and antimony present in the electrolyte, as the difference between the weights of the deposits obtained in the presence of these cations and those obtained in their absence, with the two cells connected in series. When gelatin was present along with the arsenic or antimony, it was also added to the electrolyte in the cell in series. Results and Discussion The results of the study are summarized in Figs. 1 to 6. From Fig. 1, top, it is evident that the presence of arsenic or antimony alone results in an increase of polarization, while bismuth alone causes a decrease. The presence of gelatin (25 mg per liter) rather drastically modifies all three cation effects, as indicated in the lower panels of the same figure. The addition of chloride ion, when no gelatin is present, causes comparable decreases in polarization in the presence of antimony and bismuth, but a relatively larger decrease when the electrolyte contains arsenic. It is interesting to note that the decrease in polarization brought about by addition of chloride when both arsenic and antimony are present parallels the behavior with arsenic alone, while the polarization in the electrolyte containing the cation mixture, without chloride added, corresponds to that for an electrolyte containing only the antimony cation. Similarly, the polarization at zero concentration of chloride in electrolyte containing arsenic and bismuth is that corresponding to an electrolyte containing arsenic alone. From Figs. 3a, 4a and 4b, it is clear that, in the presence of gelatin at a level of 25 mg per liter, the effect of chloride in the presence of arsenic and antimony, or a mixture of the two, becomes quite analogous to that observed in the absence of added cations. When both bismuth and gelatin are present (Fig. 5), the decrease in polarization with increased chloride concentration is virtually absent. This is perhaps a reflection of the large decrease in polarization brought about by the bismuth itself in the presence of gelatin. The shifts of the minimum in the polarization-chloride concentration curves brought about by changes of temperature (Fig. 3b), gelatin concentration (Figs. 3c and 4c) and current density (Fig. 3d) when the metal cations were present are all similar to the corresponding shifts observed in their absence." The approximately linear "excess weightv-anti-mony concentration relation recorded in Fig. 6 would seem to indicate that antimony is codeposited with copper to a considerable extent. On the other hand, only very limited amounts of arsenic appear to be adsorbed or codeposited.

Jan 1, 1954

By WILKES BARRE

AS PREVIOUSLY announced, the semi-centennial meeting of the Institute is to be held at Wilkes-Barre, Pa., on Sept. 12, 13, 14, and 15. An interesting program of technical sessions and excursions is now being prepared by the Local Committee. At the time of going to press the program had not been completed in sufficient detail to permit its being pub¬lished in this number. The detailed program will be published in the September MINING AND METALLURGY, which will be printed in time to be distributed before the Wilkes-Barre Meeting. It may be said in advance, however, that the Com¬mittee has progressed so far in its work that we are assured of one of the -most notable meetings the Insti¬tute has held and that members will miss a rare .treat if they do not attend. The many trips and excursions, as well as the banquet, will be -given to the members as a compliment from the members of the Local Com¬mittee. . . The paper by Howard Eavenson on the Lynch Plant of -the United States Coal and Coke Co. will be illustrated by lantern slides and moving pictures. One of the most appropriate discussions will be that opened by Prof. J. F. Kemp on the Stratigraphy of the Anthracite Region; this also will be amply illustrated.

Jan 1, 1921

By Thomas M. Dr. Drown

IN experimenting in connection with Mr. P. W. Shimer (now chemist of the Thomas Iron Company, Hokendauqua, Pa.) on methods for the determination of silicon in pig iron, in order to find one which should be accurate and yet give results in a few hours, I have adopted the following procedure, which, as far as my experience goes, leaves nothing to be desired. About one gram of pig iron or steel is treated in a platinum or porcelain dish with 25 cubic centimeters of nitric acid (sp. gr. 1, 2). When action has ceased, 25 to 30 cubic centimeters of dilute sulphuric acid (one of acid and three of water) are added, and heat applied until the nitric acid is nearly or quite driven off. The heat of a water-bath is sufficient, though the process may be hastened by heating higher on a sand-bath. Water is then cautiously added (as soon as the free sulphuric acid is sufficiently cool) and the contents of the dish heated until the crystals of ferric sulphate are completely dissolved. The solution is then filtered as hot as possible, the residue washed first with hot water, then with 25 to 30 cubic centimeters of hydrochloric acid (sp. gr. 1, 12), and finally with hot water. After drying and igniting, the silica will be found to be snow-white and granular. The following are some results obtained by this method compared

Jan 1, 1879

By Arthur Phillips, R. M. Brick, A. J. Smith

A previous publication1§ has described the effect of quenching stresses on the lattice parameter values of high-purity aluminum-copper alloys particularly with reference to the solution and precipitation of CuAl². A similar study has been made of the aluminum-rich aluminum-magnesium alloys. Attention has been directed in the present investigation to the magnitude of the quenching stresses as affected by the specimen size and shape, the number of solute atoms and the quenching rate. The effect of cooling stresses in causing plastic defomation or cracking has been considered in relation to the physical properties of the alloy On reheating alloys in the two-phase field, the time required for precipitation to occur has been observed in connection with the degrec of supersaturation, the rate of diffusion of the solute atoms as a function of the comparative atomic radii, degree of strain, temperature of reheating and grain size. A few qualitative comparisons on the relative effect of these factors have been drawn between the aluminum-copper alloys and the aluminum-magnesium alloys. Strain in Solid-solution Alloys A 10 per cent magnesium alloy ill the form of chill-cast bars was furnished by the Aluminum Company of America through the courtesy of L. W. Kempf. Additional alloys were prepared using alllminum (99.95 per cent Al) and high-grade magnesium. The alloys listed in Table 1 were melted in an Acheson graphite crucible under a flux of fused MgCl², CaC12, NaCI. Chill-cast rods were sealed under vacuum in Pyrex glass, homogenized several days at 450' C., air-cooled and machined to rods of from 1/8 to ¾-in. dia. Metal powders taken from these rods with a fine-toothed saw were again sealed under vacuum in

Jan 1, 1935

By R. M. Brick, Arthur Phillips, A. J. Smith

A previous publication1§ has described the effect of quenching stresses on the lattice parameter values of high-purity aluminum-copper alloys particularly with reference to the solution and precipitation of CuAl². A similar study has been made of the aluminum-rich aluminum-magnesium alloys. Attention has been directed in the present investigation to the magnitude of the quenching stresses as affected by the specimen size and shape, the number of solute atoms and the quenching rate. The effect of cooling stresses in causing plastic defomation or cracking has been considered in relation to the physical properties of the alloy On reheating alloys in the two-phase field, the time required for precipitation to occur has been observed in connection with the degrec of supersaturation, the rate of diffusion of the solute atoms as a function of the comparative atomic radii, degree of strain, temperature of reheating and grain size. A few qualitative comparisons on the relative effect of these factors have been drawn between the aluminum-copper alloys and the aluminum-magnesium alloys. Strain in Solid-solution Alloys A 10 per cent magnesium alloy ill the form of chill-cast bars was furnished by the Aluminum Company of America through the courtesy of L. W. Kempf. Additional alloys were prepared using alllminum (99.95 per cent Al) and high-grade magnesium. The alloys listed in Table 1 were melted in an Acheson graphite crucible under a flux of fused MgCl², CaC12, NaCI. Chill-cast rods were sealed under vacuum in Pyrex glass, homogenized several days at 450' C., air-cooled and machined to rods of from 1/8 to ¾-in. dia. Metal powders taken from these rods with a fine-toothed saw were again sealed under vacuum in

Jan 1, 1935

By Milton Williams

A comparison is made between the amount of interstitial water found by analysis in cores and that estimated from the resistivity curve of the electric log for the corresponding strata of producing reservoirs. It is shown that while the determined and the estimated water saturations are in good agreement in some cases, this agreement may be due to a fortuitous compensation of errors. Estimates of water saturations made from the electric 1og by use of existing relations should, therefore, be employed with caution. Also presented are data on the variation of salinity of interstitial waters in reservoir sands, and on the effect of variation of salinity and porosity on the validity of estimates of water content made from the electric log. INTRODUCTION Throughout the history of electric logging there have been recurrent cycles of optimism and pessimism as to the value of the electric log in the quantitative estimation of reservoir fluid content. The very early days of electric logging were an optimistic period, in which there was widespread faith in the ability of the resistivity curve to reflect fluid content, and in the ability of the potential curve to indicate textural characteristics. In time the accumulation of exceptions to this idealistic behavior brought about a general disillusionment, and caused the more pessimistic of those dealing with electric logs to believe that the sole importance of the log lay in stratigraphic correlation. Within the last several years optimism as to the quantitative use of the electric log has been revived, primarily as the result of the stimulating work of C. E. Archie' on the estimation of interstitial water in sands from resistivity data. Even though the general trend of thought on the quantitative value of the electric log reflects optimism, it is inevitable that there are some widely divergent opinions of the validity of quantitative estimates based on the electric log. A valid method of estimation of fluid content by means of the electric log and a general knowledge of the textural character of the reservoir rock would be of signal importance, not only in that it would save time and money in securing information on reservoirs now being drilled, but also because it would permit the evaluation of reserves in many fields drilled without adequate core data subsequent to the advent of electric logging. Because of this importance, Humble's Production Research Division, in cooperation with various other company divisions, initiated several years ago series of tests designed to evaluate the reliability of estimates of fluid content made from the electric log. The investigation was limited at the outset to sand reservoirs, since it was felt that the inclusion of limestone reservoirs would entail needless complications. In devising these tests it was immediately apparent that the chief difficulty in evaluating the worth of any method of estimation lay in establishing the true value of fluid content. The results of direct analyses of cores cut with ordinary mud were not sufficient, because of the probability of contamination of the fluids by filtrate from the drilling mud; the results of restored state tests on cores were deemed unsuitable because these results can hardly be said to furnish a primary standard. The method adopted was the direct analysis of cores cut with an oil-base drilling fluid. Such cores, when properly handled, are believed to afford the most precise determination of water content available at the present, and, in addition, lend themselves readily to the determination of various other properties which are pertinent to the estimation of fluid content from the electric log. Since it was desired to compare the fluid contents estimated from the electric log run in ordinary mud with cores cut in the same hole, the use of oil-base fluid necessitated the changing over, after all cores were cut, to a conventional mud. This procedure presented several advantages, one of which was that the use of oil-base fluid permitted

Jan 1, 1950

By M. R. Tek, M. L. Katz

The flow of fluids in stratified porous systems, in which adjacent layers of the system are in communication over part or all of their common interface, in many instances involves crossflow between layers. A theoretical study has been made of the unsteady-state flow of slightly compressible fluids during depletion of bounded stratified porous systems. Consideration has been restricted to single-phase flow, with negligible capillary and gravity effects. Analytical expressions have been derived for pressure distribution and for (luxes at the producing face in two-layer systems with complete fluid communication between layers. These expressions occur in the form of double Fourier and Fourier-Bessel series. The method of extending the solution to any number of layers is demonstrated by deriving the equation for pressure distribution in a three-layer system. On the basis of the exact results for two-layer systems, certain generalizations regarding the behavior of stratified systems in general are presented. The performance of stratified systems, in terms of cumulative flux as a function of time, is shown to lie at all times between bounds established from single-layer theory. The upper bound is given by treating the system as a single layer with arithmetic average physical properties. The corresponding lower bound is the summation of the fluxes from each layer as treated individually. Variation in performance of stratified systems between the upper and lower bounds is determined by the extent to which crossflow occurs in the system. The principal parameters affecting the amount of crossflow are the vertical permeability of the system, the ratio of system thickness to "radius of drainage" and, for radial systems, the ratio of system thickness to interior radius. At very early times, the system performance is near the lower bound. As time and the radius of drainage increase, the per- formance tends toward the upper bound. INTRODUCTION One of the principal problems confronting the reservoir engineer today is the incorporation of the effect of reservoir heterogeneity into predictions of reservoir performance. The first part of this problem is the characterization of the actual reservoir heterogeneity in a mathematically useful manner.1, 2 It is then necessary to calculate the effect of this heterogeneity on the system performance. It is frequently possible to estimate this effect by comparison with the known behavior of an idealized system. One such idealized system is the stratified or "layer-cake" model. Many studies have been made of the behavior of stratified systems, from both a theoretical and experimental standpoint. The great majority of the theoretical studies have been concerned with systems of separated layers, with no fluid crossflow. Among the more noteworthy of such theoretical papers is that recently published by Lefkovits, et al,3 in which a comprehensive analysis was presented for the behavior of bounded stratified systems which are unconnected except at the wellbore. Three recent references have dealt with stratified systems including the effect of crossflow. Jacquard4 has presented mathematical derivations pertaining to depletion of two layer systems producing at constant rate. A doctoral dissertation by Katz5 contains analytical solutions and tables of results for pressure distribution and fluid flux during constant-terminal-pressure depletion of two-layer and three-layer systems with crossflow, together with tables of eigenvalues necessary in the computations. The dissertation also presents results from experimental studies of stratified systems using a heat-transfer analog model. This paper is largely based on the material in this dissertation. A third paper has been presented by Russell and Prats6 since completion of the work resented herein, containing mathematical derivations for and discussion of the behavior

By W. Mostowitsch, H. O. Hofman

In a previous paper,' The Behavior of Calcium Sulphate at Elevated Temperatures with Some Fluxes, we published the results of our investigation into the behavior of calcium sulphate in air; that is, under oxidizing conditions. The results as a whole hold good for a neutral atmosphere, or one which has no chemical effect upon calcium sulphate. The present paper deals with the behavior of calcium sulphate under reducing conditions, the reducing-agents employed being carbon monoxide and carbon, and the changes the calcium sulphide formed undergoes when it is subjected to an oxidizing-roast. Technical literature deals very sparingly with the subject. The information furnished by the recent leading chemical manuals is general. Thus Dammer,2 Missan,3 and Abegg4 quote Berthier as having reduced, in 1823, calcium sulphate with carbon, and Stammer as having done the same in 1851

Jan 1, 1911

By A. S. C. Owili-eger

Coal mining is one of the major activities that may affect the natural or existing hydrologic equilibrium of a basin. Consequently, the mining industry is committed to the conservation and protection of the hydrologic balance within and around mining environments. This commitment embodies thorough and careful consideration of the quantitative and qualitative variations and, in general terms, the environmental impacts of mining activity on the natural water systems. A research program was undertaken to study the impacts of full extraction coal mining on the ground water systems at one of the coal basins in the Appalachian region. The primary objective was to provide reliable information for determining the local and possibly the regional effects of longwall mining on well yields, and the hydraulic and hydrogeochemical parameters of the immediate surface and subsurface water resources.

Jan 1, 1985

By P. N. Richards, M. K. Ormay

Commercially hot-rolled low-carbon steel strip may have one of two basic types of orientation texture, depending upon the amount of a iron which was present during the finishing passes. The changes in these textures with varying amounts of cold reduction up to 95 pct have been determined for the sheet surface plane and for parallel planes down to the mid-plane. The development of cold reduction textures has been reassessed on the basis of (200), (222). and (110) stereographic pole figures and pole density or inverse pole figure values. In agreement with the literature, it is shown that the textures can be described in terms of partial fiber textures but alternative descriptions are given for one of the fiber textures, in order to more closely correlate with experimental data. One partial fiber texture consists of orientations of the type (hkk)[011] extending from (100)[011] to {322}(011) in agreement with the literature. At moderate amounts of cold reduction, a second partial fiber texture forms with a <331> fiber axis inclined 20 deg to the sheet normal and a range of orientations centered on one close to (1 11)[112] and reaching to (232)[101] or (322)[011]. An alternative description involves a (111) fiber axis parallel to the sheet normal but capable of rotation about the rolling direction with rotation about the fiber axis. ORIENTATIONS developed in low-carbon steel strip after cold reduction are of commercial importance because they control, in part, the final preferred orientations after subsequent annealing. The method of control however is not understood completely. Some preliminary work indicated that the cold-reduced orientations and the subsequent annealing textures of commercial low-carbon steel were dependent on the orientations present in the material before cold reduction, that is, those present in the hot-rolled strip but, to date, the effects of initial orientations have not been extensively investigated. For this reason, much of the information given in the literature on development of preferred orientation is difficult to assess as details of initial texture and processing conditions are often inadequate or are altered by a subsequent heat treatment such as normalizing.&apos; It is known2 that anomalous results for near surface orientations may be obtained if lubrication during cold rolling is not adequate but whether lubricant was used during the experiments has not always been given, nor has the exact depth below the surface at which determinations have been made. A comprehensive review of cold rolling textures has been made recently by Dillamore and Roberts&apos; and more restricted recent reviews are due to stickels4 and Abe.5 Based largely on the experimental work of Bennewitz,1 reviewers have accepted that the preferred orientations produced on cold reducing low-carbon steel can be described in terms of two partial fiber textures as follows: Partial Fiber Texture A which has a (011) direction in the rolling direction and includes orientations within the spread from (211)[011] through (100)[Oll] to (211)[011.]; there is some controversy as to whether it extends as far as the orientation (111)[011]. As Dillamore6 has observed, the extent of this partial fiber texture depends on the intensity levels selected. Partial Fiber -texture B which has a (011) direction located 60 den from the rolling direction in the plane containing the rolling direction and the sheet normal. There are two directions which satisfy these conditions and orientations in this partial fiber texture extend from (21l)[0ll] through (554)[225] to (121)[101]. The orientations {211}(011) are members of both partial fiber textures A and B and it can be noted that a variant of {554)<225> is within 6 deg of a variant of {111}(112). Barrett7 had postulated earlier that, in addition to orientations which would fall into partial fiber texture A, a true fiber texture with a (111) direction in the sheet normal was present after heavy cold reduction. This fiber texture would include orientations such as {111}(011) and {111}(112). Later investigators, notably Bennewitz,&apos; have discounted this, mostly on the ground that the partial fiber textures A and B, as described above, contain all the strong orientations that have been observed. However in other work it has been reported2 that (222) pole density or inverse pole figure values show a continuing increase with increasing reduction by cold rolling and give values considerably greater than for any other low indices plane. Thus it could be inferred that a (111) fiber texture as described by Barrett would be one which becomes more dominant with increasing cold reduction, whereas Bennewitz&apos; concluded that components such as {554)(225) in partial fiber texture B began to decrease in intensity at high reductions. Following Bennewitz, one would expect a decreasing (222) pole density value (parallel to the sheet normal) with increasing cold reduction. Because fiber textures consist of grains with a range of orientations that have one axis in common, it has been inferred that during deformation the crystal orientations rotate about the fiber axis&apos;74 and that the orientations of crystals that at one stage belong to one fiber texture can rotate on further cold reduction into the other fiber texture through an orientation in which the two fiber textures intersect.&apos; For example,

Jan 1, 1970

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&apos;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 R. C. Croft

Many chemical methods of upgrading ilmenite to enhance its titanium dioxide content involve reduction of the FeO in this mineral followed by solution of the metallic iron produced. While the use of most mineral acids for this purpose entails acid regeneration or salt disposal problems, these difficulties can be overcome with carbonic acid. Satisfactory rates of iron removal have been achieved at temperatures below 100° C and at CO, pressures up to 600 psi. Lowering of gas pressure over soluble bicarbonate solutions permits recovery of CO. and precipitation of iron oxide. The removal of the manganese, often present in ilmenites, is also feasible with these treatments.

Jan 1, 1972

By Sir Robert Hadfield

Table 1 gives the composition of the specimens listed by the author. The details of test procedure and the results of the tests on mechanical, magnetic and electrical properties and cor-rodibility of the alloys are published in full in a paper by the same author, "Alloys of Iron and Manganese Containing Low Carbon," presented before the Iron and Steel Institute (of Great Britain) and published in full in their Proceedings for 1927, to which reference should be made. After reporting these tests the author gives the following discussion of results:] The studies here reported do not indicate that any of the series has really valuable or useful qualities for industrial applications, though the demands of industry are so varied that it is unsafe to prophesy that no special use will be found for a given material. The non-magnetic property of manganese steel is due to the association of Fe and Mn, but carbon has also an effect, enabling non-magnetic qualities to be obtained with a much lower percentage of Mn than would otherwise be the case; for example, 16 per cent. Mn is necessary for alloys practically free from carbon, while with 1 per cent. C nonmagnetic alloys may be obtained with as little as 7 per cent. Mn. Carbon, however, is the prime cause of the development of magnetic qualities by heat treatment. (Sec section 8 of the paper referred to above.) These Fe-Mn alloys show a resistance up to 87 microhms per c. c., but. as there are other alloys which have a resistance as high as 130 microhms per C. c., this does not provide any new feature of value. The most marked feature of the series studied is the brittleness in the range 3 to 10 per cent., with a maximum of brittleness at 7 per cent. Material with this percentage, while possessing quite appreciable hard-

Jan 1, 1927

By John Richards

MY remarks will be confined to the experience of our company in mining the No. 8 seam of coal in Ohio, although I believe that the relationship existing here between the method of mining and the method of cleaning will hold true in many of the coal seams throughout the country. The increasing demand for a cleaner and better graded product is being felt throughout the entire coal industry, and the methods of mining are playing an important part in the control of various sizes and quality of coal produced. We have found a definite relation between the mechanical loading of coal and its preparation for the market. In the No. 8 coal seam the location of the non-combustible material is regular. The&apos; marketable coal lies in three benches, separated by streaks or bands of impurities. These impurities must be removed from the coal to properly pre pare the product for the market. Where hand-loading methods are employed, the loader removes as much of this non-combustible material as possible at the working face. The impurities that are missed by the loaders are removed as the coal passes through the preparation plant, by means of picking tables. As this method of cleaning cannot improve the quality of the extremely fine sizes, a practice has been established in the company&apos;s hand-loading mines, of undercutting the coal about 2 in. above the bottom of the seam, thereby eliminating any possibility of impurities caused by the cutting machines cutting into the rock bottom below the coal seam.

Jan 1, 1934

By Horace Knerr

The term. "high-yield-strength," used in the title of Dr. Gillett&apos;s paper (p. 40) is obviously relative. His discussion is limited to improved steels intended to compete with the low-cost, low-carbon, hot-rolled, sheet and plate steels of commerce made and used on a tonnage basis, without heat-treatment. In his list of about three dozen steels, only three have a yield strength of 70,000 lb. per sq. in., or over. Double such values are not uncommon in aircraft steels. Dr. Jeffries (p. 21) refers to "light-weight metals," obviously meaning strong alloys of low specific gravity; namely, aluminum alloys of the duralumin type and certain magnesium alloys. In a structural material, "lightness" is determined by two factors, strength and specific gravity. They must always be considered jointly. The basis of comparison is a strength-weight ratio, obtained by dividing the desired strength value, such as tensile strength, yield strength, or endurance limit, by weight per unit of volume, such as specific gravity or pounds per cubic inch1. For example, aluminum is a heavy metal, structurally, unless alloyed and heat-treated to give it high strength. When the strength of a structural metal is raised by heat-treatment or by cold-work, its specific gravity is not appreciably changed, but it is made lighter in direct proportion to the increase in strength because less of it will be required to carry the load. The lightness of the finished structure of adequate strength is the real point of interest. This structure must not only carry designed load, but "stand the gaff" of service, which includes the effects of accidental overload, fatigue, corrosion, loosening of joints, and so forth. Neither Dr. Gillett nor Dr. Jeffries mentions the true "lightest material of construction," which is alloy steel, tubular in form (Fig. 1), assembled by welding and heat-treated to a yield strength in excess of 150,000 lb. per sq. inch.

Jan 1, 1936

By Frank Firmstone

Discussion of the paper of John B. Dilworth, presented at the Pittsburg meeting, March, 1910, and printed in Bulletin No. 35, November, 1909, pp. 1041 to 1043. FRANK FIRMSTONE, Easton, Pa. (communication to the Secretary*) :-Mr. Dilworth&apos;s formulas and tables are of course correct, and the extinction will occur as calculated, provided the money periodically set aside for sinking-fund be really invested. and the interest compounded as assumed in the calculation. Actually, in almost all cases, such funds are used "in the business," in which case, in addition to the periodical charges for principal of the fund, additional charges must be made at the end of each period to cover the interest and compound interest on previous charges. The periodical charge for sinking-fund thus becomes a varying and continually increasing one until the date of extinction. On many accounts it seems more natural and convenient to make the extinction by a fixed periodical charge under the legal rule for partial payments, namely, that each payment should apply first to the interest due at the date of payment;: and any remainder, after this is satisfied, be deducted from the principal before the interest for the next period is calculated. The formula below is convenient for such calculations S, Principal to be extinguished. Q, Periodical payment or charge for sinking-fund. B, Balance unpaid at date of nth payment, but before that payment is made. r, Rate of interest per period per cent. n, Number of payments or periods. Then, B=S(1+r)n-Q(1+ r)n-(1+r) Received July 27, 1910.

Apr 1, 1911

By J. R. Lucas, R. L. Frantz

Mine sealing programs for the alleviation of acid mine drainage were begun by the Federal Government in the &apos;30&apos;s. As part of an acid mine research project to The Ohio State University, a field test was undertaken to determine the effectiveness of mine seals for reducing mine acid. Details of the tests made at the McDaniels mine show the feasibility of air-sealing and flooding an acid-producing drift coal mine. Work by the University continues. The Federal Government undertook in the early thirties an extensive mine sealing program for the alleviation of acid mine drainage. In the states of West Virginia, Ohio, and Pennsylvania many general summaries have been made on this program but no critical evaluation with supporting data has been found on the effectiveness of mine seals for reducing mine acid. Because of this it was decided to undertake a field testing program as part of an acid mine research project of the Engineering Experiment Station, The Ohio State University. The objective of this phase of the project was to develop and install a field research laboratory for acid mine drainage studies. Specifications for such a mine laboratory were developed and resulted from the following considerations: 1) Size and preservation—the test mine shou1d be of limited size to permit frequent and detailed examinations; it should be in a reasonably sound condition to permit safe entry. 2) Isolation—the mine should be physically separated from all other mines. 3) Openings—a minimum number would be desirable to reduce the sealing problem. 4) Structure—the mine especially near the openings should be structurally sound. 5) Acid production—the mine should be producing significant quantities of acid. After considerable searching, the McDaniels mine was selected in the Hocking coal field in Vinton County just above Lake Hope State Park in southeastern Ohio. The small drift mine in the middle Kittaning coal consisted of two small rooms with one mine opening about 6 ft above a seasonal stream bed. Before it was finally decided to seal the mine, a short study was made of the acid drainage over several months. Fig. 1 shows a plot of acidity (milligrams per liter), flow (gallons per minute), and acid production (pounds per day) vs time over the sampling period. Because the coal was overlain with a porous sandstone, the mine drainage was consistent the year around even though the mine was

Jan 1, 1961

By K. J. Miller, R. E. Hucko

The Coal Reparation Division of the Pittsburgh Mining Technology Center conducted an investigation to assess and compare the pyritic sulfur reduction potential of coal-pyrite flotation and high-gradient magnetic separation (HGMS). Tests were run on three coals - an Upper Freeport bed coal, a Lower Kittanning bed coal, and a Pittsburgh bed coal - to establish grade-recovery relationships characteristic of both processes. Representative portions of each coal sample were crushed to two top sizes-nominal - 500 pm (-35 mesh) and nominal - 149 pm (-100 mesh)-and subjected to conventional froth flotation. The froth product was then beneficiated by coal- pyrite flotation or HGMS, to provide a direct technical companion of the two processes. At - 500 pm (- 35 mesh), the size normally employed for coal flotation, both coal-pyrite flotation and HGMS effectively separated pyrite from coal, and the performance of the two processes was essentially the same. At a - 149 pm (- 100 mesh) sire, however, the performance of HGMS exceeded that of coal-pyrite flotation. The separation effected by HGMS were more efficient at - 149 pm (- 100 mesh) than at - 500 pm (- 35 mesh). On the other hand, it was concluded that either the effectiveness of coal-pyrite flotation decreases with diminishing top size or the process has not been optimized to treat material finer than 500 pm (35 mesh).

Jan 1, 1983