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By C. G. Dunn, J. L. Walter

Secondary recrystallization to the (110) [001] texture in high-purity silicon iron occurs if low-oxygen material is annealed in a nonoxidizing atmosphere. Any departure from these conditions results in a growth of (100) oriented grains. The nature of the matrix and secondary recrystallization structures and textures and the nature of grain boundary interactions during growth show that the low gas-metal interfacial energy of the (110) surfaces provides the driving force for growth of these grains. A type of grain growth, characterized by a driving force which derives from energy differences of {hkl} surfaces at the gas-metal interface, has been treated in recent papers.&apos;-7 Secondary recrystallization to the cube text!:: in high-purity silicon iron provides one example. The present paper also deals with a surface energy driving force but the texture that results by secondary recrystallization is not the cube texture; it is a texture in which the (110) plane is in the plane of rolling and the [001] direction is in the direction of rolling. The phenomenon described in this paper is different from the impurity (dispersed phase)-controlled secondary recrystallization process in which the (110) [001] oriented grains grow under the action of grain boundary driving forces.8-12 It is also different from tertiary recrystallization,2 which also produces the (110) [001] texture in high-purity silicon iron, since the matrix textures and grain sizes are different. Finally, it is unlike any other form of secondary recrystallization reported in the literature. The possibility of obtaining the (110) [001] texture in high-purity silicon iron became clear in a study of the effect of impurity atoms on the energy relationships of (100) and (110) surfaces. In this study Walter and Dunn6 observed the migration of (100)/(110) boundaries, i.e., boundaries between two grains, one of which has a (100) plane and the other a (110) plane, respectively, parallel to the plane of the sheet specimen. At 1200°C the (100)/(110) boundaries advanced into (100) grains in a vacuum anneal, then reversed their direction and migrated into (110) grains in a subsequent anneal in impure argon. Finally, the direction of migration reversed once again with (110) grains growing into (100) grains in a second vacuum anneal. These results were explained in terms of a change in concentration of oxygen atoms at the gas-metal interface during the anneals. Thus, oxygen atoms were added to the surface during the anneals in impure argon to the point where ?100, the specific surface energy of the (100) oriented grains, was lower than ?110, the surface energy of (110) oriented grains. In vacuum, however, the oxygen concentration at the surface was lowered to the point where ?110 < ?100. Concerning the possibility of secondary recrystallization in high-purity silicon iron with a low initial oxygen concentration, the observed effect of adsorbed oxygen atoms has indicated6 that a good vacuum anneal would favor the rapid growth of matrix grains with the (110) plane in the plane of the sheet much more than grains in the (100) orientation. The growth of only (110) oriented grains of course would depend upon y110 being less than ?hkl, where hkl refers to any plane different from (110). The present paper is concerned with the application of the above ideas to secondary recrystallization to the (110) [001] texture in high-purity silicon iron. The matrix and secondary recrystallization textures and structures are defined and discussed. Observations of growth of nuclei for secondary recrystallization and of boundary interactions are included to provide direct information on the surface energy relationships between (110) and other (hkl) surfaces. EXPERIMENTAL PROCEDURE As before, 2,4-6 high-purity iron and silicon were melted and cast in vacuum to provide an alloy containing 3 pct Si with less than 0.005 wt pct impurities. The oxygen content of the ingot was lower than in previous ingots, being approximately 3 ppm (by weight). The carbon content of this ingot may have been slightly higher than was found for previous ingots. The same rolling and annealing schedule used previously2 was followed in this study to obtain samples 0.012 in. (0.3 mm) thick. These samples were electropolished prior to annealing. After rolling and polishing, the oxygen content of the material was approximately 6 ppm; material used in the previous studies contained about twice this amount of oxygen.

Jan 1, 1961

John J. Porter, Cincinnati, Ohio (communication to the Secretary *):—The remarks of Mr. Firmstone concerning the presence of nickel in Oriskany ores, call to my mind some additional evidence on this point. In 1903, while engaged in the determination of zinc in a number of samples of ore from the Oriskany mine of the Alleghany Ore & Iron Co., I was surprised to discover the presence of nickel and cobalt. As far as I was then able to discover, their present;! had up to this time remained unnoticed. The amounts ranged from 0.05 up to 0.10 per cent. of the combined oxides, and while no attempt was made to separate the metals, the presence of both nickel and cobalt was conclusively proven. Since that time I have learned that traces of these metals are of quite general occurrence in Virginia iron-ores, and more especially in the ores of the Potsdam formation from the western slopes of the Blue Ridge. In certain manganese-ores from this formation, I have found as high as 0.50 per cent. of nickel and cobalt oxides. Any one interested in this subject will find further information in a volume l written by Andrew 8. McCreath, and printed in 1884 for distribution by the Norfolk & Western railway. A number of complete and accurate analyses of Virginia iron-and manganese-ores are given, and practically all show nickel and cobalt in appreciable quantity. Still another source of information on the occurrence of nickel in iron-ores in the United States, for which I am indebted to Charles Catlett, is found in the Tenth Census. Several analyses of Oriskany ores are given: all of which show the presence of nickel, with less cobalt, while the single representative from the Potsdam formation shows nickel, with no cobalt.

Jan 1, 1909

By R. H. Jacoby, M. J. Rzasa

Experimental equilibrium vaporization ratios were obtained for nitrogen, methane, carbon dioxide, ethane, and hydrogen sulfide in natural gas-condensate systems. Two different overall mixture compositions were investigated over the pressure range 500 to 4,000 psia at 100°, 150°, and 200 °F. Partial phase diagrams of the mixtures were obtained; one of these showed a critical point at 204°F and 3,875 psia. These and earlier data&apos; were compared with the Kellogg correlation&apos; at! 100°F and 1,000 psia. INTRODUCTION The authors&apos; have presented equilibrium vaporization ratios for nitrogen, methane, carbon dioxide, ethane, and hydrogen sulfide in complex mixtures, such as natural gas-crude oil and natural gas-absorber oil. Since mixtures of the natural gas-condensate type also occur widely in petroleum reservoirs and often contain the non-hydrocarbons mentioned, it would be useful to have appropriate K data for calculating equilibrium vaporization conditions. Roland, Smith, and Kave-ler&apos; obtained K&apos;s for methane and the light hydrocarbons in gas-condensate mixtures; and Poettmann and Katz3 obtained K&apos;s for carbon dioxide in a gas-condensate system. The data presented in this paper extend this coverage to include K&apos;s for nitrogen and hydrogen sulfide and phase diagrams for the experimental mixtures. EXPERIMENTAL WORK The equipment and experimental procedure was essentially as described previously, except for analysis of the vapor samples. The vapor sample bombs were filled at the pressure and temperature of the run. Immediately after sampling, a portion of this sample was flushed from the bomb into a 650 cc glass bulb, filling it to near atmospheric pressure. The sample in the glass bulb was then analyzed by the mass spectrometer. Some checks were made on this analytical procedure to find the accuracy of measurement of the C + content of the vapor samples. The modifications tried were complete fractionation of the vapor sample and the use of several liquids (depropanized condensate and retrograde liquid from several vapor samples) as calibrating materials for the mass spectrometer. The results obtained from these various checks differed by about 10 per cent relative and this is believed to be the order of accuracy of the vapor C+ concentrations.

Jan 1, 1953

By G. Kimmel, A. Bar-Or

The rate of nucleation and the rates of both lateral and longitudinal growth of martensite plates (needles) in b—a transformation were determined as a function of temperature, in various U-Cr alloys. The activation energies for nucleation and both modes of growth were calculated from the experimental results. The identical values for lateral and longitudinal growth clearly indicate that both are controlled by the WHITE,&apos; Mott and Hines and Holdeen3 showed that characteristic martensite plates (needles) appear in U-Cr alloys during the transformation 8 —0 in the lower temperature range (up to -300°C). Holden pointed out that the rate of growth of the individual martensite plates under isothermal conditions is same mechanism. Lomer&apos;s suggestion that single-atom movement over subatomic distances controls the specially slow growth of martensite receives further support from the present kinetic study, which shows that the growth rate can be described quantitatively by known formulas for the growth rate in processes involving single-atom movement. very slow, and suggested that this is due to the slowness of the relief of the stresses engendered during the growth of the individual plates. lomer4 attributed the slow growth to the complexity of the atomic adjustment at the growing interface b/(u. In the present work the rates of nucleation and growth of martensite plates in U-Cr alloys were studied by direct observation, in order to elucidate the mechanism which controls their characteristic slow growth.

Jan 1, 1968

By D. M. Collingwood

The year 1928 has been marked by scattered but considerable wildcat drilling considering the overproduction prevalent in the oil industry. This wildcatting has resulted in the discovery of oil in one interior salt dome, several small fields producing from serpentine, Taylor marl, and Austin chalk, and two new fields producing from the Edwards limestone, one of which in the Bruner or Salt Flat area of Caldwell County promises to be of major importance if not quite as large as the Luling field. Fig. 1 shows production by fields for 1928, compared in the case of the older fields, with that for 1927. New Production From Salt Domes Boggy Creek Dome This salt dome was discovered in 1927 by core drilling and deep tests recommended on the evidence of surface geology. A large block of acreage controlled by the Humble Oil & Refining Co. covers the dome. Since the discovery of the deep-lying salt plug and oil on the flank of this dome in 1927, development has proceeded slowly. Since most of the acreage is controlled in a large block by one company there has been no intensive competitive drilling. Approximately 8 producers and 16 dry holes have been drilled. Production is from the eastern equivalent of the Woodbine and Eagleford horizons of the Mexia district, and has been found extending in a northeast-southnlest direction across the River Neches on the southeast flank of the dome. One of the best wells, the T. H. Jones No. 2, had an initial production of 90 bbl. per hr., and others have made from 100 bbl. per day to 50 bbl. per hr., but production of the better wells has either been shut in or choked down to less than 2000 bbl. per day. At the end of the year the daily average, production was about 2500 bbl. from 8 wells. Considerable gas pressure is present and one well, the Elliot Clark No. 2, drilled in 1927, was shut in with an estimated wet gas production of over 5,000,000 cubic feet.

Jan 1, 1929

By W. A. Tiller, W. C. Johnston

The solute distribution ahead of an advancing solid-liquid interface is controlled by varying the momentum boundary layer thickness in the liquid adjacent to the interface. Single pass zone-melting experiments on Pb-Sn alloys are described in which the liquid is caused to rotate in the plane of the solid-liquid interface due to the influence of a magnetic .field rotating in this plane. The variation of the diffusion boundary layer thickness with field strength is determined. DURING the freezing of an alloy a partitioning of solute occurs at the solid-liquid interface, the magnitude depending upon the difference in the solid and liquid solubilities at the interface temperature. Because the diffusion coefficient is so small in the liquid relative to normal freezing rates, either a pileup or a depletion of solute occurs at the interface when the partition coefficient, kO, is either less than or greater than unity, respectively. This solute distribution is completely characterized by i) the solute concentration in the liquid far from the interface, C) the ratio of freezing velocityf, to diffusion coefficient, D, iii) the partition coefficient, ko, and iv) the thickness of the diffusion boundary layer, 6,, at the interface (this assumes that an electric field is not applied across the interface). For a particular system, C ko and D are fixed so that the character of the solute distribution can be changed only by a variation of either f or 6c. As is well known, the freezing velocity can be changed by varying the thermal environment of the alloy. Whereas, the thickness of the solute rich layer can be changed by varying the fluid flow conditions in the liquid. It is the purpose of this paper to describe a technique for controlling the fluid flow conditions in the liquid. During most solidification experiments the driving force for fluid flow arises from either mechanical mixing, thermal convection or electromagnetic mixing. The momentum boundary layer thickness, 6m at the solid-liquid interface, within which negligible movement of the liquid occurs, has been calculated for the special case of mechanical mixing where crystals are solidified by the Czochralski technique.l,2 The calculation of 6m for the case of thermal convection has also been made.3 In some calculations it has been assumed that the momentum boundary layer thickness, 6,, may be equated to the thickness of the diffusion boundary layer 6c, at the interface. However, as may be seen from Appendix I this is only true in very special cases and in general where a is a constant of magnitude determined by the particular liquid alloy. Neither calculations nor experimental data exist for the dependence of upon electromagnetic mixing. In this paper experiments are described in which the liquid is caused to rotate in the plane of the interface due to the torque developed on it by a magnetic field, H, rotating in this plane. The variation of is controlled by the variation of H. A magnetic field rotating in a plane perpendicular to the interface has been used for the purification of aluminum. Experimentally, we determined the variation of 5C with H by using the zone-melting technique of pfann5and a theoretical relationship of Burton et a1.2 pfann5 has shown that, after the passage of one molten zone through a long cylindrical charge of uniform concentration, CO, the solute distribution, C,, in the solid is as shown in Fig. 1. The equation describing this distribution is

Jan 1, 1962

By T. H. Alden

A correlation has been found in rock-salt structure single crystals between the latent hardening, measured by the direct stress activation of oblique slip systems, and the stress-strain behavior in simple compression. Materials with high latent hardening, like LiF, strain-harden at a low rate (Stage I) even when severely constrained. KCl, in contrast, shows low latent hardening and a tendency to strain-harden at a high rate (Stage 11). This correlation suggests that oblique slip is essential for Stage II hardening of these materials. THE role of secondary slip in the strain hardening of metal single crystals is a topic of lively controversy. On the one hand are theories in which secondary dislocations participate directly in Stage II hardening in the fcc metals, for example through the production of sessile dislocations,1 forest intersections, or jog formation. Much of the experimental evidence on which these theories are based has been reviewed by Clarebrough and Hargreaves.~ On the other hand, a recent theory5 denies that secondary slip has an essential role in Stage II hardening or in the transition from Stage I to Stage 11. In the latter view, Stage I is not terminated by an increase in the activity of secondary systems but by the exhaustion of undeformed material.6 The experiments reported in this paper will not resolve this controversy since the materials being studied are cubic ionic crystals rather than metals. However, the results do show in an unusual way a direct connection between "secondary" (nonortho-gonal or oblique) slip and strain hardening in these materials. Specifically, a correlation has been found between two independently measured properties, first the latent hardening of oblique (110)(1i0) slip systems as measured by direct stress activation of these systems, and second the stress-strain behavior at small strains. From prior work, it was known that in most cubi-cally oriented rock-salt structure crystals, two orthogonal slip systems operate and exclude the other equally stressed pair, oblique to the first pair.7&apos;8 This observation apparently indicates that a significant interference exists between slip on oblique (110) planes and a relatively small interference between orthogonal (110) planes. The present experiments were begun with the intent of obtaining a quantitative measure of this difference by means of a study of latent hardening in these crystals. I) EXPERIMENTAL METHODS The experiments were basically of two types, first the determination of stress-strain curves by compression along a single (100) axis, and second the measurement of latent hardening by compressive prestrain along one cube axis followed by the determination of the yield stress in a second (latent) cube direction. All tests were done at room temperature in an Instron machine by compression between lapped, parallel steel faces. Three specimen shapes were used. For long crystals (nominal dimensions, 1/8 in. square by 1/2 in. long) the ends were lubricated with an oil-graphite mixture. Superior results with short crystals (about 1/8 in. cube) were obtained using 0.003-in. teflon film.&apos; Thin crystals (1/4 in. square by 3/32 in.) were used for latent-hardening measurements and similar results were obtained with either lubricant. Test specimens were cleaved from Harshaw single crystals which had been irradiated to a dose of lo8 roentgen using a cobalt-60 source. The irradiation raises the yield stress and tends to prevent plastic deformation during sample preparation.10 Prior to testing, the irradiation hardening was removed by an anneal at 400°C. Ideal compression specimens have flat, parallel faces. In short specimens particularly, satisfactory results demand a close approximation to this ideal. In the present work, cleaved surfaces were often used directly as compression faces. The degree of success using this method depends on two factors: 1) the smoothness of cleavage faces, and 2) the extent to which the crystal is deformed or crushed by the chisel during the cutting of a long crystal into short pieces. Unfortunately, only one material of those studied, LiF, was completely satisfactory. NaF, NaC1, KC1, and KBr behaved less well so that

Jan 1, 1964

By Gerhard Derge

Metallurgists have used borax as a fluxing agent traditionally, but until recently elemental boron has played an insignificant role as an alloying element. Neither the metal nor its compounds have been regarded as important metallurgical materials and there is a surprising lack of knowledge concerning their metallurgical behavior. The new applications to steel-making of both boron and borates, which arose in part from wartime incentives and restrictions, have been seriously handicapped by this lack of data. For example, rasorite, a naturally occurring sodium borate, has been shown to be an effective substitute for aluminum as a ladle deoxi-dizer in rimming steels.&apos; Likewise, the effectiveness of boron as an alloying agent has been demonstrated,2,3 giving deep hardening when used in restricted amounts. The exploitation of both of these uses has been retarded by the difficulty of attaining suitable metallurgical control. Recognizing that the most important information required was a knowledge of the equilibrium between boron and oxygen dissolved in liquid iron. Gurry4 calculated this relation from the best thermal data available. However, estimates of the entropy of melting of boron, the activity coefficient of boron in liquid iron and the activity coefficient of B2O3 in slag were involved, and experimental work on this problem was obviously desirable. The experiments to be described were planned to establish the boron-oxygen relations in liquid iron and to demonstrate at the same time the ferroborate slag compositions in equilibrium with various amounts of oxygen in liquid iron. Accordingly, slags containing varying proportions of iron and boron oxides were held in contact with molten iron, and samples of both slag and metal were analyzed. The limitations upon the accuracy of the data will be considered, but in a practical sense the oxygen levels that can be attained in iron by iron borate slags, and the amounts of boron in iron at these oxygen levels were established. Experimental Procedure No entirely suitable refractory was found for the mixtures of iron oxide and boron oxide used as slags. Crucibles of silica, magnesia, Ramix, beryllia, and zirconia were all tried unsuccessfully. The must satisfactory method discovered for handling them was the rotating-crucible technique, which creates a parabolic crucible of liquid iron.5,6 Even this was not entirely successful, for at steelmaking temperatures (1600°C.) the slags had such a low surface tension that they crept up to the refractory and slowly dissolved it. These difficulties made it impossible to maintain a constant slag composition for an unlimited period Of time. However, by using the rotating technique, short runs could be made in

Jan 1, 1947

By Gerhard Derge

Metallurgists have used borax as a fluxing agent traditionally, but until recently elemental boron has played an insignificant role as an alloying element. Neither the metal nor its compounds have been regarded as important metallurgical materials and there is a surprising lack of knowledge concerning their metallurgical behavior. The new applications to steel-making of both boron and borates, which arose in part from wartime incentives and restrictions, have been seriously handicapped by this lack of data. For example, rasorite, a naturally occurring sodium borate, has been shown to be an effective substitute for aluminum as a ladle deoxi-dizer in rimming steels.&apos; Likewise, the effectiveness of boron as an alloying agent has been demonstrated,2,3 giving deep hardening when used in restricted amounts. The exploitation of both of these uses has been retarded by the difficulty of attaining suitable metallurgical control. Recognizing that the most important information required was a knowledge of the equilibrium between boron and oxygen dissolved in liquid iron. Gurry4 calculated this relation from the best thermal data available. However, estimates of the entropy of melting of boron, the activity coefficient of boron in liquid iron and the activity coefficient of B2O3 in slag were involved, and experimental work on this problem was obviously desirable. The experiments to be described were planned to establish the boron-oxygen relations in liquid iron and to demonstrate at the same time the ferroborate slag compositions in equilibrium with various amounts of oxygen in liquid iron. Accordingly, slags containing varying proportions of iron and boron oxides were held in contact with molten iron, and samples of both slag and metal were analyzed. The limitations upon the accuracy of the data will be considered, but in a practical sense the oxygen levels that can be attained in iron by iron borate slags, and the amounts of boron in iron at these oxygen levels were established. Experimental Procedure No entirely suitable refractory was found for the mixtures of iron oxide and boron oxide used as slags. Crucibles of silica, magnesia, Ramix, beryllia, and zirconia were all tried unsuccessfully. The must satisfactory method discovered for handling them was the rotating-crucible technique, which creates a parabolic crucible of liquid iron.5,6 Even this was not entirely successful, for at steelmaking temperatures (1600°C.) the slags had such a low surface tension that they crept up to the refractory and slowly dissolved it. These difficulties made it impossible to maintain a constant slag composition for an unlimited period Of time. However, by using the rotating technique, short runs could be made in

Jan 1, 1947

By John C. Ludlum

A most stimulating event in the development of world mineral production and technology, the Eighth Commonwealth Mining and Metallurgical Congress was convened at Melbourne Town Hall on March 1 by Sir Maurice Mawby, President of the Congress. Continuing successively at Melbourne, Canberra, Sydney, and Surfers Paradise in Australia and then at Wellington, New Zealand, the four plenary sessions, 50 technical sessions, and both local and extended mine and plant tours during the seven weeks of the Congress, provided a superb medium for assessing the present and looking into the future. There were more than 2300 participants from 32 countries in the various functions of the Congress, including 500 delegates and wives from countries other than Australia and New Zealand, and from 18 countries not members of the British Commonwealth of Nations. Registrants from South Africa numbered close to 200 and there were about 100 from Canada, 70 from the United Kingdom, 60 from the United States, and 20 from Zambia. Although most of the overseas delegates held administrative positions with companies, government agencies, and colleges or universities, professions identifiable from registrations included 100 engineers, 60 geologists and 30 metallurgists.

Jan 8, 1965

By J. C. McCarthy, J. B. Stone

At Fresnillo a series of veins that has yielded very large quantities of silver and other metals has been developed over a length of 6500 ft. and to a depth of over 3000 ft. In the course of this work striking changes in the mineralogy and metal content of the principal veins have been disclosed and are well illustrated by assay data and ore reserve calculations. This paper describes those changes and suggests their bearing on theories of ore deposition. Location The Fresnillo mines and the adjacent city of Fresnillo are in the central part of the state of Zacatecas, 35 miles northwest of the capitol city of Zacatecas, once a great silver-mining center whose total production is said to place it fourth in. the world. Another famous old silver district, Sombre-rete, lies northwest of Fresnillo. Fresnillo is connected by a 5-mile branch with Fresnillo On on the Mexican National Railways line from Juarez to Mexico City. Lying near the southwestern edge of the central plateau of Mexico, Fresnillo is Surrounded by a semi-arid rolling plain from which rise widely scattered low hills. One of these is Proano hill, an inconspicuous elevation rising barely 300 ft. above the plain, but in and around Proano hill are the Fresnillo mines, and it is marked now by a great gash cut by glory-hole mining. According to an account written in 1834 by Francisco Garcia, then Governor of the state of Zacatecas, Fresnillo was discovered in 1554, and a presidio was established there in 1568 to protect travelers on the road between zacatecas and sombreretea Little is known of the earliest mining at Fresnillo, which seemingly began soon after its discovery, but by piecing together various accounts, it appears that mines there were working in 1717 and were notably active in 1751 under an administrator named Murguia, who left detailed notes describing them. In I757, however, the mines became inactive because of dificulties with creditors and no doubt also because of increasing water troubles, and they remained abandoned until 1830. In 1830 the mines at Fresnillo became the property of the State of Zacatecas because the interest of Governor Garcia had been aroused by the long disregarded notes of Murguia. Under Garcia&apos;s energetic leadership the mines were reopened, and silver production began in 1832 in spite of serious difliculties, including abnormal rains and an epidemic of cholera. In 1835 English capital was sought to allow installation of steam-driven is pumps at the two principal shafts and to build the great hacienda de beneficio (the present Proano hacienda). The company formed in 1835 (Cia. Zacatecano-Mexicana) operated successfully until 1872, when its career was brought to an end by the political and economic disturbances

Jan 1, 1949

By J. C. McCarthy, J. B. Stone

At Fresnillo a series of veins that has yielded very large quantities of silver and other metals has been developed over a length of 6500 ft. and to a depth of over 3000 ft. In the course of this work striking changes in the mineralogy and metal content of the principal veins have been disclosed and are well illustrated by assay data and ore reserve calculations. This paper describes those changes and suggests their bearing on theories of ore deposition. Location The Fresnillo mines and the adjacent city of Fresnillo are in the central part of the state of Zacatecas, 35 miles northwest of the capitol city of Zacatecas, once a great silver-mining center whose total production is said to place it fourth in. the world. Another famous old silver district, Sombre-rete, lies northwest of Fresnillo. Fresnillo is connected by a 5-mile branch with Fresnillo On on the Mexican National Railways line from Juarez to Mexico City. Lying near the southwestern edge of the central plateau of Mexico, Fresnillo is Surrounded by a semi-arid rolling plain from which rise widely scattered low hills. One of these is Proano hill, an inconspicuous elevation rising barely 300 ft. above the plain, but in and around Proano hill are the Fresnillo mines, and it is marked now by a great gash cut by glory-hole mining. According to an account written in 1834 by Francisco Garcia, then Governor of the state of Zacatecas, Fresnillo was discovered in 1554, and a presidio was established there in 1568 to protect travelers on the road between zacatecas and sombreretea Little is known of the earliest mining at Fresnillo, which seemingly began soon after its discovery, but by piecing together various accounts, it appears that mines there were working in 1717 and were notably active in 1751 under an administrator named Murguia, who left detailed notes describing them. In I757, however, the mines became inactive because of dificulties with creditors and no doubt also because of increasing water troubles, and they remained abandoned until 1830. In 1830 the mines at Fresnillo became the property of the State of Zacatecas because the interest of Governor Garcia had been aroused by the long disregarded notes of Murguia. Under Garcia&apos;s energetic leadership the mines were reopened, and silver production began in 1832 in spite of serious difliculties, including abnormal rains and an epidemic of cholera. In 1835 English capital was sought to allow installation of steam-driven is pumps at the two principal shafts and to build the great hacienda de beneficio (the present Proano hacienda). The company formed in 1835 (Cia. Zacatecano-Mexicana) operated successfully until 1872, when its career was brought to an end by the political and economic disturbances

Jan 1, 1949

By C. D. Stahl, S. M. Farouq Ali, W. E. Culham

One- and two-dimensional mathematical models have been developed that simulate transient, two-phase flow of hydrocarbon mixtures in porous media in a manner that accounts for interphase mass transfer. Numerical simulations of one-dimensional depletion-drive experiments using a two-component hydrucarbon fluid were used to establish the validity of the mathematical models. In addition, the experimental and numerical data were used to demonstrate that production rate had a relatively insignificant effect on the recovery of individual hydrocarbon components from the experimental system, and that attainment of equilibrium between phases is possible for a wide range of liquid and vapor velocities in reservoirs containing light hydrocarbon fluids. Results of some two-dimensional numerical simulations are also presented. INTRODUCTION This study was undertaken to develop a mathematical model that would simulate transient, two-phase flow of hydrocarbon mixtures in porous media under conditions that result in interphase mass transfer and to test the validity of the assumptions used to set up the model. In addition, the study was designed to determine if production rate influences the recovery of individual hydrocarbon components from reservoirs producing by depletion drive. Two-phase flow in porous media, with interchange of components between the two phases, is important in many petroleum recovery processes. Studiesl-5 conducted within the last 3 years have outlined methods of solving multiphase flow problems incorporating mass transfer. Some of these studies have also indicated the importance of accounting for mass transfer under various producing conditions. An earlier work6 first demonstrated the importance of combining relative permeability data with equilibrium ratios in compositional balance methods. The mathematical model presented in this paper is formulated so that a phase behavior package, as described in previous papers,5,17 is not required as an integral part of the routine employed to solve for the primary dependent variables. The finite difference formulation is designed so that all the primary variables can be solved for simultaneously. This is accomplished by utilizing one basic set of equations. These innovations, which are in contrast to other models2,3,5 but are similar in some respects to the approach used by Taylor,l render the total problem computationally simpler than any of the previously referenced formulations. The mathematical model was developed by combining Darcy&apos;s law with a continuity equation for each hydrocarbon component. The principal assumptions invoked in the formulation were (1) that capillary forces and diffusional effects are negligible, and (2) that thermodynamic equilibrium exists in the reservoir at all times. No assumption as to the type of vaporization process was made in formulating this model. Experimental data were required to complete this study. These were generated by conducting several depletion drive experiments. The experimental apparatus consisted of a sandstone core enclosed in a pressurized casing. The apparatus was designed in such a manner that the core could be charged with a liquid hydrocarbon mixture and depleted at different production rates. The experimental tests were designed to determine the effect of production rate on component recovery. In addition, direct comparison of experimental and mathematically predicted

Jan 1, 1970

By Y. C. Liu, R. H. Richman

Deformation and recrystallization textures of the a solid solutions of Cu-P, Cu-As, and Cu-Sb alloys are examined as a function of composition. It is found that the deformation texture of copper is unckanged up to a composition of 0.43, 0.41, and 0.24 at. pct of phosphorus, arsenic, and antimony, respectzvely, and then the transition to the 70 : 30 brass type of deformation texture proceeds linearly as the logarithm of the solute content. Recrystallization textures consist of strong, new components that do not all bear the usual<111> rotational relation to the deformation components. The dependence of the deformation texture transitions and the recrystallization orientations upon composition and solute-element type is discussed. A systematic evolution of individual recrystallization components in the annealing texture of copper was portrayed as a function of germanium or tin content in a previous study.&apos; Similar patterns of tex-tural change have been observed with copper-zinc alloys,2 and in less detailed studies of other systems.3,4 In fact, most of the literature dealing with preferred orientations in copper alloys indicates that the influence of solute elements upon textures in copper is of one general type. As the alloy content of copper is increased, the deformation texture changes from the copper type to the 70:30 brass type, and the annealing texture undergoes a comparable change from the (001) [ loo] orientation of unalloyed copper to the {113} <211> type of 70:30 brass, with the notable exception of copper alloyed with Periodic Subgroup V-B elements.4-8 In almost every case it is possible to describe the reorientations after annealing as 30 to 40 deg rotations about <1ll> poles of the deformation components. Since there is apparently not much difference in the final textures of the copper binary systems already investigated, only a limited variety of preferred orientations has served as the basis for current theories of the origin of annealing textures. In order to test the validity of the proposed theories, and the possibility that the <111> rotations are not unique, it would be most desirable to study the reorientation relationships of additional, and heretofore unanalyzed, recrystallization components if such components exist. Examination of the literature reveals a good deal of uncertainty concerning preferred orientations in copper alloyed with elements in Subgroup V-B of the Periodic Table. Phosphorus is known to inhibit the cube texture in copper when present in amounts as low as 0.01 wt pct,8 but the recrystallized matrix that occurs instead of the cube orientation was reported as either random or weakly textured, with orientations not observed in Cu-Zn, Cu-Ge, or Cu-Sn alloys.4-9 A Cu-0.75 at. pct As alloy apparently contained, along with the (001)[100] and (113) <211> type of recrystallization components, {110} <112> and (110) <001> components, whereas an almost random distribution of orientations was found in alloys of higher arsenic content.4 A {110} <001> component also appeared in rolledand annealed Cu-Sb alloys, but otherwise the recrystallization textures of Cu-Sb alloys seem to con-

Jan 1, 1962

By William P. Blake

THE occurrence of enormous masses of pure copper has given the mining district of Lake Superior worldwide reputation. The first masses brought from there excited great attention, and directed the notice of the mining world to the few particular mines from which they were taken. It may not now be generally known that nearly all the veins which are worked, and which cut across the trap ridge, contain mass copper, and that large masses are continually being raised from them. The largest continuous mass which has been taken out was probably that from the Minnesota, in 1857, which is variously stated as weighing 420 tons and 470 tons. Its length was about 45 feet, its breadth or height 22 feet, and its greatest thickness 8 feet. All such masses are very irregular and ragged in their form and thickness, thinning out generally from a foot to a few inches, and straggling through the vein until they connect with other large masses. This was the character of a mass found in the Phoenix Mine, one of the oldest on the lake, which mass altogether weighed some 600 tons. But this was really a series of masses more or less connected by strings of metal, yet no one large part of it weighed, singly, over 200 tons. A similar series of masses, weighing about 600 tons, was extracted from the Minnesota. Some of the Phoenix masses were four to five feet thick of solid copper. The Cliff Mine has yielded masses weighing from 100 to 150 tons in one piece. One of 40 tons was taken out this year, besides numerous blocks weighing from 1 to 8 tons. This mine and the Central are now yielding mass copper in abundance. It is, of course, impossible to pick, or drill, or to break out such huge masses of solid metal when they are found, by drifting upon the course of the vein. The method of extraction is as follows The miner picks out or excavates a narrow passage or chamber upon one side of the mass, laying it bare as far as possible over its whole surface. It is usually firmly held by its close union with the vein-stuff, or by its irregular projections above, below, and at the end. If it cannot then be dislodged by levers, the excavation of a chamber is commenced behind the mass, and this excavation is made large enough to receive from 5 to 20 or more kegs of powder. In one

Jan 1, 1876

By William P. Blake

The occurrence of enormous masses of pure copper has given the mining district of Lake Superior worldwide reputation. The first masses brought from there excited great attention, and directed the notice of the mining world to the few particular mines from which they were taken. It may not now be generally known that nearly all the veins which are worked, and which cut across the trap ridge, contain mass copper, and that large masses are continually being raised from them. The largest continuous mass which has been taken out was probably that from the Minnesota, in 1857, which is variously stated as weighing 420 tons and 470 tons. Its length was about 45 feet, its breadth or height 22 feet, and its greatest thickness 8 feet. All such masses are very irregular and ragged in their form and thickness, thinning out generally from a foot to a few inches, and straggling through the vein until they connect with other large masses. This was the character of a mass found in the Phœnix Mine, one of the oldest on the lake, which mass altogether weighed some 600 tons. But this was really a series of masses more or less connected by strings of metal, yet no one large part of it weighed, singly, over 200 tons. A similar series of masses, weighing about 600 tons, was extracted from the Miunesota. Some of the Phœnix masses were four to five feet thick of solid copper. The Cliff Mine has yielded masses weighing from 100 to 150 tons in one piece. One of 40 tons was taken out this year, besides numerous blocks weighing from 1 to 8 tons. This mine and the Central are now yielding mass copper in abundance. It is, bf course, impossible to pick, or drill, or to break out such huge masses of solid metal when they are found, by drifting upon the course of the vein. The method of extraction is as follows: The miner picks out or excavates a narrow passage or chamber upon one side of the mass, laying it bare as far as possible over its whole surface. It is usually firmly held by its close union with the veinstuff, or by its irregular projections above, below, and at the end. If it cannot then be dislodged by levers, the excavation of a chamber is commenced behind the mass, and this excavation is made large enough to receive from 5 to 20 or more kegs of powder. In one

By Nelson Severinghaus

AS far back as 40 years ago management made the initial steps toward utilizing the large amount of reject marble produced by the dimension stone quarries in sized products. In 1947 the Calcium Products Div. of the Georgia Marble Co. was organized to manufacture crushed, ground, and screened products from Georgia marble.* It became obvious early in operations that salability of any products of this type was determined by several factors: high calcium carbonate content, whiteness, dryness, and cleanness. Because no reject material could consistently meet these specifications, Calcium Products Div. now operates three underground quarries for raw material feed. In underground operations no stripping is required, surface contamination and trash are eliminated, weather causes no operational difficulties, and the raw material is maintained dry for plant processing.

Jan 12, 1957

By Milton Fies

ALTHOUGH pig iron from iron ore and red cedar charcoal preceded the mining of coal by many years, for tradition says that Alabama iron was used to shoe the horses of Andrew Jackson&apos;s soldiers, coal was not produced until 1830. In that year, coal was mined in Tuscaloosa County, in the vicinity of what is now the University of Alabama, and shipped on flat boats (obviously during the wet season, for there were many shoals) down the Warrior River to Mobile. About that time, the first railroad, the Decatur & Tecumseh, was being constructed in northern Alabama to overcome the obstructions to freight traffic caused by the now well-known Muscle Shoals in the Tennessee River. This railroad was patterned after a railroad at Mauch Chunk, Pa., which was used for hauling anthracite from the Panther Creek valley. The Alabama railroad, which required about four years to complete, was 46 miles long and was used solely for the transportation of cotton. Although it was a failure, it demonstrated the practicability of the undertaking, and the succeeding railroads, which were begun in 1834, 1848, 1852, and 1853, added immeasurably to the development of the coal resources of the state. Between the years 1830 and 1860, practically all the coal mined in the state was dug from the outcrop near the river or from the river beds, and shipped by boat to Mobile. Transporting coal down the Warrior River was one of great risk, required much skill, and frequently had heavy losses. It is recorded that this coal was sold to the gas company in Mobile in 1844; it was most likely mined from the Black Creek Seam. In 1914, on the completion of Lock 17, the Warrior River became a navigable stream from 9 miles above Cordova, Ala., to Mobile and offers a great opportunity for the future development of the coal resources of the state.

Jan 9, 1924

US 4,181,588 - Direct extraction of lead from lead sulflde ore. Ore is leached with a solution of ferric chloride and sodium chloride. The leach liquor is filtered to remove sulfur and gangue, then cooled in a crystallizer to precipitate lead chloride The slurry from the crystallizer is subjected to electrolysis to deposit lead chloride on the cathode plate. Solution from the electrolysis cell is used in the leaching step. M.M. Wong and F.P. Haver, assigned to US Secretary of the Interior Jan 1, 1980. 6 pp. (204-115). Filed: 1-4-79 (1,026).

Jan 1, 1982

By J. W. Rutter, K. T. Aust

The migration of individual, large-angle grain boundaries has been studied as a function of tempereature and solute concentration in specimens of zone i.e filled lead containig very small additions of silver and of gold. Tile results are compared with various the-ories of grain boundary migration and with observations made prev.iorlsly of grain boundary migration in similar specimens of zone-refined lead containing tin additions. A previous investigation by the authors dealt with [he temperature dependence of grain boundary migration in bicrystals of zone-refined lead containing small additions of tin.&apos; It was shown that tin additions as low as a few parts per million cause a large decrease in the grain boundary migration rate at any given temperature, as well as a marked increase in the temperature dependence of the migration rate. It was found that existing theories of grain boundary migration. based on the motion of dislocations. or upon the concept of atom transfer in groups across the boundary (group process theory). or upon the control of grain boundary motion by volume diffusion of impurity atonls along with the boundary. are incapable of accounting for the observations. The single process theory of grain boundary migration. which is an absolute reaction rate calculation based on the transfer ui atoms singly across the moving boundary, was found to predict the migration rate reasonably well for a number of boundaries whose motion was shown to be very little influenced by impurities, but not for boundaries whose illation was influenced markedly by impurities. It was concluded that the elementary process of grain boundary migration involves the activation of single atoms during transfer across the boundary. and that inadequate knowledge is available to permit the influence of impurities to be properly taken into account. The present study was initiated to check the validity of the above conclusions with other alloy systems, namely high-purity lead with small additions of silver and of gold. Both silver and gold diffuse faster. and with a lower activation energy of volume diffusion. than does tin in lead;&apos; consequently, a study of the effects of silver and gold on grain boundary migration in high-purity lead offered a means of testing theories of boundary migration based on bulk diffusion of the solute (eg. ref. 3). In addition. it was hoped that the present work, in comparison with the results for tin in lead, would provide information concerning which factors are important in determin- ing the interaction between solute atoms and a grain boundary. EXPERIMENTAL PROCEDURE The preparation of bicrystals of zone-refined lead, with various silver or gold additions, was identical to that previously described for the lead-tin alloys.&apos;&apos;4 Each bicrystal consisted of a striated crystal which was grown from the melt. and an adjacent striation-free crystal which was introduced by artificial nucleation and growth.&apos;&apos;4 The striation or lineage substructure in the melt-grown crystal provided the driving force for grain boundary migration. During the preparation of striated single crystals by growth from the melt, it was found that silver or gold concentrations as low as 2 or 3 ppm by atoms were sufficient to cause formation of the hexagonal cell structure. which is due to the presence of impurity, during freezing. This structure is revealed on the solid-liquid interface by decanting the liquid during freezing. The hexagonal cell structure was observed previously4 in zone-refined lead crystals with tin contents above approximately 200 ppm by atoms. These concentrations of silver, gold, or tin are in agreement with the predicted amounts required for cell formation in lead,5&apos;6 under the present conditions of freezing.4 The absence of cell structure at decanted interfaces, therefore, served as a useful indication that the silver or gold contents were less than 2 or 3 ppm by atoms in the specimens as grown. It was found that grain boundary migration occurred only very slowly when the solute content approached that necessary for cell formation. As a result, the present experiments were conducted with silver or gold additions less than 1 ppm by atoms. This impurity level is well within the solid solubility limits for silver and gold in lead.7 The annealing treatments, measurements of grain boundary velocities, and orientation determinations were carried out as described previously.&apos; However. each bicrystal was also chemically polished in a solution consisting of 8 parts glacial acetic acid and 2

Jan 1, 1961