Search Documents

By J. V. Calara, J. D. Miller

The sign of the surface potential for complex non-reactive ionic solids cannot be predicted solely from consideration of the hydration energy of gaseous ions which constitute the ionic lattice. Accurate analysis of these systems must involve the hydration energy of surface ions, which requires knowledge of the crystal structure, the identification of cleavage planes, and the calculation of binding energies of surface ions. Surface binding energies for ionic solids can be determined if the Surface Madelung Constant is known. A computational technique was developed for the calculation of Madelung Constants for infinite lattices which gives excellent agreement with the values calculated by other more complicated methods reported in the literature. Extension of this technique permits the calculation of Surface Madelung Constants and binding energies of surface ions, [Aus], for semi-infinite solids. The hydration free energy of gaseous ions, [AFh], together with the calculated binding energy of surface ions, [Aus], allows calculation of the hydration energy of surface ions,[AGh], as for the case of the ionic solid, MX: [ ]

Jan 1, 1976

By Donald B. Evans, Robert D. Pehlke

The solubility of nitrogen in liquid Fe-B alloys has been measured up to the solubility limit for the formation of boron nitride. The activity coefficient of nitrogen increases with increasing boron content in the range 0 to 7 wt pct B. From experimen -tal data, values have been calculated for the B-N interaction parameter e3 at temperatures in the range 1550" to 1750°C. A value of 0.038 has been estimated for the boron self-interaction parameter eg at 1550°C. The standard free energy of decomposition of boron nitride into the elements dissolved in liquid iron has been determined to be: ?F° = 45,900 -21.25T in the range from 1550° to 1750°C. The nitride is assumed to be of composition BN. BORON nitride has an unusual combination of properties which make it appear attractive in a wide range of engineering applications. Some of its more important and most recent applications are in the nuclear area, particularly in connection with the liquid-metal cooled reactor concept now receiving considerable emphasis. Boron nitride has a high degree of stability at elevated temperatures. It also has excellent ma-chinability and the ease with which its crystals deform suggests applications as a lubricant. These properties stem from a hexagonal layer-type structure similar to the structure of graphite. One of its primary uses to date has been for seals in liquid-metal pumping systems. It is also used in nuclear reactors as an insulating layer to separate two solid metals which are not themselves compatible under the conditions of temperature and atmosphere in which they are used. Its inertness to liquid metals has also suggested use as a mold-release agent in casting processes. In addition to its excellent machinability and reported inertness to liquid metals such as iron, silicon, aluminum, copper, and zinc, boron nitride has high thermal conductivity and excellent thermal shock resistance. This combination of properties would make it appear ideal as a refractory crucible material for refining of high-purity liquid metals, for example high-quality steels. However, since it is known that concentrations of boron as low as 50 ppm can have a marked effect on the physical properties of certain steels,' in particular on the creep and stress-rupture properties, an investigation was undertaken to define accurately the chemical equilibrium among boron, nitrogen, and liquid iron in the range of steelmaking temperatures. EXPERIMENTAL PROCEDURE Two experimental approaches to this problem were employed: a Sieverts' method and a quenching method. In the first method, the Sieverts' technique was used to measure the equilibrium nitrogen solubility in liquid Fe-B alloys of 0 to 7 pct B as a function of nitrogen gas pressure over the melt. The solubility limit of the boron nitride phase formed was determined by the point of departure of the nitrogen absorption from Sieverts' Law. This technique has been applied to liquid Fe-Ti alloys by Rao and parlee,' to liquid Fe-A1 alloys by Evans and Pehlke,3 and to solid Fe-V alloys by Fountain and Chipman.4 In the second method a melt of liquid iron was held in a crucible of boron nitride under a known partial pressure of nitrogen gas. After thermodynamic equilibrium was attained, the melt was quenched in a stream of helium and then analyzed by wet-chemical methods for boron and nitrogen. The Sieverts' apparatus used in the first method was essentially of the same design as the one described by Pehlke and Elliott.5 The charge materials were vacuum-melted high-purity iron (Ferro-vac E) supplied by the Crucible Steel Co. and -325 mesh boron powder supplied by Cooper Metallurgical Associates of Cleveland, Ohio. The boron contained less than 0.02 wt pct O, according to supplier's analysis. Recrystallized alumina crucibles were used to contain the melt. Examination of solidified melts showed these crucibles to be satisfactory with no evidence of any reaction or physical penetration of the crucible wall by the melt. The melt temperature was measured by a disappearing filament-type optical pyrometer sighted vertically downward on the melt surface through a 1/4-in.-diam sight hole in the crucible lid. The pyrometer was calibrated against the melting point of pure iron in the same apparatus, taking the emissivity of

Jan 1, 1964

By Ellis Clark

These mines were discovered by George W. Lufkin in August, 1878, and mere worked almost continuously until August, 1893, a period of fifteen years. The ore-deposits in this locality lie close to the surface, and it is strange that the Spaniards, passing and repassing for nearly three centuries, did not discover them, particularly as they are marked in several places by large outcrops of black flint and iron, which would lead even a casual observer in a mineral country to suspect the proximity of ore. The mines are situated about six miles from the old Santa Fé trail, and fifteen miles from the Rio Grande. The geology is such that a skilled geologist passing over the ground would probably suspect, from the peculiar arrangement of the formations, the occurrence of ore. The formations in the district, eruptive and sedimentary, are nine in number; and of these eight are to be found within one thousand feet of the Grande workings. Topography. The topography of the Lake Valley district shows its dependence on the surface and underground geology, in a degree more marked

Jan 1, 1895

By K. Mukherjee

Instantaneous resistance change during martensitic transformation in Fe-30 at. pct Ni alloy has been studied using a low-noise electronic system. The smallest signals recorded in this investigation were of the order of 10 pv. These small signals did not show the initial increase reported by earlier investigators to support a double shear mechanism.&apos; A variety of pulse shapes and sizes was observed during "burst" transformations, and these signals were neither a linear function of the size of martensite plates nor of the volume fraction transformed. Even the smallest signals, presumably from single plates, showed complications resulting from elastic and/or plastic deformation, shock wave propagation, and so forth, which are inherent in the growth process of a martensite plate. The time of formation and interface velocity determined froni this experiment agree very well with the pioneering work of Bunshalz and Mehl.&apos; AN Fe-30 at. pct Ni (c0.005 pct C) alloy was used to study the time of formation of martensite plates. Martensitic transformations, unlike the nucleation and growth processes, are usually characterized by an extremely fast reaction rate. During the transformation, the crystal structure changes and this change is propagated through a finite volume of the parent crystal lattice within a very short time interval. The interface between the two phases probably consists of moving dislocations, and the time of formation of the plate depends on how fast this dislocation interface can move. Knapp and Dehlin~er or Cottrell and Bilby mechanisms, or similar dislocation models, can be used to calculate the time of formation of a martensite plate of a given size. In the past, conventional photographic technique475 as well as electrical resistivity techniques"~-" have been used to measure the time of formation of a martensite plate. The specific resistance of the martensitic phase in Fe-30 at. pct Ni alloy is lower than that of the austenite phase. Therefore if a current is passed through a small austenite sample in series with a large external resistance, then one would observe a voltage change across the sample as martensite is formed. Such dc measurements are shown in Fig. 1. The initial large voltage drop in Fig. 1, at the M, temperature, is due to a "burst" transformation where a large number of plates are formed in a cataclysmic manner within a very short interval of time. Even during the later stages of transformation as shown in Fig. 1, one can observe discontinuous voltage changes due to small bursts. In order to resolve the time scale of such discontinuous stages, the voltage signals are amplified and fed into a highspeed oscilloscope. In this investigation a low-noise amplifier was used for the first stage of amplification. The signal to noise ratio was further improved by the design of a pulse transformer. This transformer was capable of amplifying the signal by a factor of six. Voltage signals were studied over a wide time scale ranging from 2 sec to 0.1 psec. I) EXPERIMENTAL PROCEDURE A) Specimen Preparation. Specimens were cut from induction-melted Fe-30 at. pct Ni (<0.005C) alloy and cold-rolled to 0.2 by 1 mm cross section and an average length of 5 cm. During mechanical shaping, the specimens were strain-annealed at 950°C for 24 hr in vacuum. Finally the finished samples were vacuum-annealed at 1000°C for 6 hr and water-quenched to room temperature. The average grain diameter was 0.02 cm. B) Cooling System. The M, temperature of the alloy was -55°C. Fig. 2 shows the arrangement which was used to cool the specimen at a slow rate. The specimens were mounted inside a i -in.-diam hole in the 2-in.-long section of the copper specimen holder. This cavity was filled with silica gel. A dummy specimen was used under identical conditions for

Jan 1, 1969

By Charles B. Dudley

In view of various papers and discussion.;, at recent meetings of the Institute, upon testing, methods of testing, inspectors, inspection and specifications, it has occurred to me that my experience of some fifteen years, in the making and enforcement of specifications, in connection with the Motive Power Department of the Pennsylvania Railroad, might give some value to the few suggestions offered in this paper. There is friction, not to say antagonism, between the producers and the consumers of structural materials. On the one hand, the producers complain of the severity of inspection, or the lack of knowledge and want of good judgment on the part of inspectors, and, indeed, have gone so far as to suggest the abolition of the whole scheme of inspecting and testing materials. On the other hand, the consumers are, apparently, more and more relying on specifications

Jan 1, 1893

By Kenneth S. Ritchie

THE discovery well of the world&apos;s -deepest oil producing structure, University 1-B of Group No. One Oil Corporation, in the Big Lake oil field, Reagan County, Texas, has had a remarkable record. The well is outstanding for the following reasons: (1) It is the world&apos;s pioneer well to produce. oil in commercial quantities from a structure 8500 ft. below the earth&apos;s . surface; (2) this well was the only. producer from the 8500-ft. pay for a period of 17 months and 24 days; (3) the flow of the discovery well has been free from-the customary changes at the casinghead, with the exception of putting on a back-pressure of 185 lb.; and, (4) the well&apos;s daily production of oil and gas increased rather steadily for 17 months and 18 days from an initial of 40 bbl. per day to a maximum of 2926 bbl. per day, and then six months later, after a period of decline and self-readjustment to subsurface changes caused by six more deep producers, the well set its real record for one day&apos;s production of oil at 2950 bbl

Jan 1, 1931

By Sam Tour

WHAT is a die-casting and what is the die-casting industry? From the literal translation of the words "die" and "casting"&apos; one concludes that a die-casting is a casting made in a die. The casting may be of any metal or alloy or, for that matter, may be of some nonmetallic material capable of being cast, such as plaster of paris or glass. The die may be of any material that will take successive casts so it need not necessarily be metallic in nature. The term "die-casting," therefore, is indeed broad, though in practical usage it has come to mean the casting of metals and their alloys in metallic molds or dies. Even this limitation of the term leaves -a broad field, for castings may be made in a number of different ways. For example, the molten metal may be allowed to run into the die by gravity it may be sucked into the cavity of the die, it may be forced to take the contour of the cavity in the die by centrifiugal force, or it may be forced into the cavity under hydrostatic pressure. In England, castings made by practically all of these

Jan 1, 1935

By J. H. Palm

Experiments have shown12 that the formula -S = St - (St - Se&apos;)e ne [1] expresses very well the relation between the true stress S and the true form monotonic deformation of plastic metals in single tension and compression (Fig 1). St (asymptotic or final stress), Se&apos; (threshold stress) and ne (characteristic or specific strain) are constants, the significance of which immediately follows from Fig 1. Only at the initial stages of deformation the experimental curve runs below the theoretical curve. This may be due, at least partly, to the uneven stress distribution caused by the anisotropy of the crystals. It is now obvious that a similar formula H = Ht- (Ht- He)e ne&apos; [2] might be valid for the relation between the hardness and the strain. The hardness can be only a function of the strain and must therefore be independent on the hydrostatic tension present in the neck during straining. Hence, if Eq 2 is correct it will also represent the relation between hardness and strain in the middle section of the neck, the strain of which is generally assumed to be almost or fully homogeneous. For aluminum, copper, and several copper alloys it is indeed observed that Eq 2 agrees very well with the experimental Vickers hardness-strain relation from zero strain on up to the strain at fracture. Moreover nc&apos; is, for several metals fairly equal to nc- Hence H = C1 + C2S [3] C1 and C2 are constants during uniform uniaxial tension. Eq 3 was also obtained for copper by Voce.3 According to Hencky&apos;s theory4 the ratio of the Brinell or Vickers hardness and the yieldstress (expressed in kg per mm2) of a non-strainhardening metal is approximately equal to 2.8. If Eq 1, 2 and 3 are correct the ratio Ht/S, must accordingly be the same for all plastic metals and be equal to 2.8. It is now experimentally established that this ratio varies between 2.7 and 3.1 with a mean value of 2.9. Taking into account that Ht and especially St can be obtained only by extrapolation from the range of rather low strains, the agreement with the theory is very satisfactory. References 1. J. H. Palm: Appl. Sci. Res. Al (1948) 198. 2. E. Voce: Jnl. Inst. of Met. (1948) 74, II, 537. 3. E. Voce: Metal Treatment (1948) 15, 53. 4. H. Hencky: Zlsch. f. angew. Math. and Mech. (1923) 3, 241.

Jan 1, 1950

By B. E. Sundquist

The various methods based on solution models for obtaining free energies of mixing from miscibility-gap data have been applied to a number of binary-alloy systems. For nine of these systems there exist experimental thermodynamic data that permit a comparison of the results to experiment. It was found that the method of van der Toorn and Tiedema almost invariably leads to results that are physically unacceptable and that vary drastically with small changes in the miscibility-gap parameters. The subregular solution model is found in all cases, except the Al-Zn, Fe-Cr, and Cu-Pb systems, to exaggerate the free energy of mixing by 30 pct or more. The model developed by Lumsden is found to give results that are often in excellent agreement with experiment and which exaggerate the free energy of mixing by no more than 30 pct. These results and others give evidence that the Lumsden treatment of the effect of unequal atomic sizes and of imperfect configurational randomness due to deviations of AB bond energies from the mean of AA and BB bond energies is adequate for most systems. ANALYTIC expressions are frequently proposed for the dependence on composition of the activities of the components of a solution. Because the development of solution theory is incomplete, these expressions contain parameters which must be determined by experiment. The measurement of activities is often difficult and consequently such measurements are less readily available than are measurements of phase equilibria which, under certain conditions, can also be used to evaluate these parameters. For example, suppose it is known that two structurally dissimilar phases, each of known composition, in an n-com-ponent system are at equilibrium at a given temperature and pressure. n equations can be set up in terms of these parameters expressing the equality of the chemical potential of each component in the two phases. In addition, one can write the Gibbs-Duhem equation for each phase that also contains these parameters. Thus, if these n + 2 equations contain n + 2 parameters, these parameters can be determined (at the temperature in question) from the phase diagram alone. If the average number of parameters in each expression for the activity of a given component in a given phase is V then there will be 2nV parameters involved. Equating 2nV to n + 2 shows that, for n + 2, V = 1. If the temperature dependence of each parameter were to be expressed in some explicit form one could use equilibrium conditions at a number of temperatures to increase V. The situation is much improved when the two phases in equilibrium are structurally similar. It can then be assumed that, stably or metastably, two phases will become one at higher temperatures. Thus the number of parameters involved becomes nV instead of 2nV. Hence, V = 2 for n = 2 using only one temperature. (It is implied here that the activity expressions used are valid over the entire composition range.) In this investigation only the equilibrium of two structurally similar, two-component phases (miscibility-gap systems) will be considered. The various proposed solution models will be applied to a number of these systems and the results compared with available experimental results. All of the analytic expressions that have been proposed for the free energy of mixing of a two-component system are of the form where ?Gmix is the free energy of mixing per mole of solution, N1 and N2 are the mole fractions of components 1 and 2, respectively, and f(Ni, T) is some function of composition and temperature. In the "ideal" solution model f = 0. In the "regular" solution model f = a constant. Since these two models permit only a symmetric equilibrium diagram they will not be considered further here. The simplest model that permits a nonsymmetric miscibility envelope is the so-called "subregular" solution model proposed by Hardy.1 This model gives where the Ci(T) are functions of temperature only. The same expression for f is obtained from the "linear a function" model proposed by Darken and Gurry2 and applied to miscibility-gap systems by Wriedt.3 This model requires that the a function defined by be a linear function of composition (yi is the activity coefficient of component i). This model is not purely hypothetical for it has been found2 to hold true for a number of systems. It is readily shown3 that the f(Nl, T) obtained from this model is of the form given in Eq. [2]. It will be noted that the subregular solution model contains only two parameters and hence both of them can be determined at any desired temperature below the critical temperature, Tc, for a miscibility-gap systems in the manner described previously. At T, the two constants can be determined by equating the second and third derivatives of ?Cmix with composition to zero. Another two-parameter model was proposed by Lumsden4 who set

Jan 1, 1967

By R. E. Ogilvie, N. L. Peterson

Diffi-lsion measurements were conducted at all compositims in the bcc solid solution of the U-Nb system employing incremental couples at composition intemals of 10 at. pct. Diffusion coefficients were determined by the Matano method from concentration gradients obtained with the electron-probe microanalyzer. The activation energy for inter-diffi-lsion as a function of compositim shows three distinct regions: 1) 80 to 100 pct U.6= 30 kcal per mole; 2) 20 to 80 pct U, $ - 70 kcal per mole; 3) Oto 20 pet U, Q = i40 kcal per mole. The frequency factor, fi0 and the activation energy $ were found to be roughly related by the following equation: log Do ^9.7 X IO-5Q -6,6. The Kirkendall marker movement indicates that DU is larger than DNb between 16 and 100 pct U and DNb is larger than DU from 0 to 4 pct U. FOR practical as well as fundamental reasons, the rates of diffusion in alloys are of considerable consequence. Most solid-state reactions are largely dependent upon the diffusion of atoms through the lattice structure and along grain boundaries. The high-temperature strength and reasonable nuclear properties of niobium have prompted its use as a reactor material in contact with uranium fuel. Hence, diffusion data for the U-Nb system are of considerable importance. In the previous diffusion study1 on the U-Nb system using pure element couples, reliable data were obtained only in the range of 0 to 10 at. pct Nb due to the large variance of the diffusion coefficient with composition. Also, a large Kirkendall effect and considerable porosity in the uranium-rich areas of the specimen were reported, which suggests that the true diffusion coefficients are somewhat larger. The purpose of the present study was to obtain reliable diffusion coefficients at all compositions using incremental diffusion couples with intervals of 10 at. pct. In view of the abnormal self-diffusion be- havior of y uranium2-4 and some other bcc transition elements,&apos;-&apos; it was felt that a comparison of the interdiffusion coefficients in the bcc U-Nb system with those of Reynolds et al.9 for the fcc gold-nickel system might shed some light on the diffusion mechanism involved. Both systems have similar phase diagrams, in that complete solid solubility exists above a miscibility gap. EXPERIMENTAL PROCEDURE The uranium used in this investigation was obtained through the courtesy of Argonne National Laboratory. An analysis of this material detected only Si-30, A1-7, C-6, N < 10 and 0-18 ppm. The niobium was electron-beam melted material obtained from Stauffer-Temescal. The gaseous impurities were less than 50 ppm, and the spec troc hemical analysis showed Ta-500 and W-200 ppm. U-Nb alloys were prepared at composition intervals of 10 at. pct by melting the appropriate amounts of the pure elements in an arc furnace. The buttons were inverted and remelted 6 times to assure complete mixing. The buttons were then wrapped in molybdenum foil, canned in Zircaloy-2 or stainless steel, and hot rolled 30 pct reduction in thickness at temperatures between 850" and 1100°C. Alloys with 10, 20, 30, 40, and 90 at. pct Nb rolled quite easily under these conditions, but the 50, 60, 70, and 80 pct alloys remained brittle. After melting and rolling (when possible), the alloys were annealed for 24 hr at a temperature within 100°C of their melting point in a dynamic vacuum of better than 4 x 10-8 mm Hg. These treatments produced alloys which were homogeneous on a 1 p scale within the detectability limits of the electron probe. During fabrication, the alloys picked up as much as 100 ppm Mo and 100 ppm Zr. Other elements checked for but not found were Co, Cr, Fe, Mn, Ni, and Ti. The grain size of the annealed samples ranged from 3 mm for the uranium-rich alloys to 0.3 mm for the niobium-rich alloys. This permitted measurements of the concentration gradients in the diffusion samples without crossing more than one or two grains, thereby eliminating any grain boundary effects. The specimens were bonded by theU&apos;picture frame" technique as reported by Kittel.10 Specimens of composition b)U + (100 - x)Nb were sandwiched between two specimens of composition (x + 10)U + (90 - x)Nb after they were ground flat and parallel

Jan 1, 1963

By T. Sterry Hunt

This remarkable mine, to which attention has lately been drawn, is situated not far from the New River, in Ashe County, North Carolina, on a spur of the Blue Ridge which lies between the main crest of this name and the so-called Iron Mountain, a part of the Unaka or Smoky Mountain range. It is on a true fissure-lode, which cuts the strata of gneiss and mica-schist of the region. These, which have the lithological characters of what I have called the Montalban or White Mountain series, have here a dip of about forty-five degrees to the southeast, while the lode is vertical, with a course north 60&apos; east. Both the country-rock and the lode, as is usual in this region, are decomposed to considerable depths; and the latter exhibits a cap of hydrous peroxide of iron or gossan, blocks of which, left by the denudation of the softer inclosing rock, are scattered over the surface, and first called attention to the locality as a source of iron ore. In sinking upon this lode, it was found that the porous gossan at a certain depth became charged with carbonate and red oxide of copper, and lower down was replaced by sulphuretted ores of this metal of remarkable richness. This deposit was worked for copper, in an irregular manner, before the late civil war, but was afterwards abandoned, and only reopened during the present year, by Messrs. S. S. & J. E. Clayton, of Baltimore. The outcrop has been traced for 1900 feet, and the sulphuretted copper ores have been met with in five shafts in a distance of 661 feet, a drift having moreover been carried for the above distance through the solid ore. The breadth of the lode, so far as opened, varies from six to eight feet to fourteen feet in places, and that of the outcrop of gossan is, in some parts, twenty feet. After comparing this deposit with the copper mines of Ducktown, Polk County, Tennessee, and those of Carroll County, Virginia, it is evident that we have, at Ore Knob, to do with the same kind of black ores as were met with in these mines, and will be noticed further on, Beneath the gossan, at Ore Knob, is found, in some parts, an iron-black, friable, drusy, crystalline, sulphuretted ore, inclosing grains of quartz, garnet, and magnetite, besides a black non-magnetic mineral, not attacked by nitric acid. This ore contains about 36 per cent. of copper, and portions have the mineralogical charac-

By G. V. Jere, C. C. Patel

Chlorination of the various constituents of ilmenite by different chlorinating agents in presence of various reducing agents, have been considered on the basis of the standard free energy and standard enthalpy changes as a function of temperature. The standard free energy change considerations show that it is beneficial to chlorinate ilmenite by chlorine in the presence of carbon and also that iron constituent of ilmenite can be preferentially chlorinated by clzlorine, titanium tetrachloride or their mixture. These findilzgs have been corroborated from the published work. METALLURGICAL processes involving the use of titanium tetrachloride have gained in importance because of the use of the latter in the manufacture of titanium metal. Since ilmenite is more abundant in nature than any other titanium mineral, the future of the metallurgical processes depends on the utilization of ilmenite for the production of titanium tetrachloride. In these laboratories, investigations have been carried out on the chlorination of ilmenite under a variety of conditions.1&apos;2 During these studies, it was noticed that 1) preferential chlorination of iron was effected at low temperatures (400° to 600°C) and at low carbon content (6 to 7 pct), 2) carbonyl chloride retarded the chlorination of iron oxides and titania perceptibly, while 3) carbon-tetrachloride, compounds of sulphur and some other catalysts favored the chlorination. Moles3 has found that oxides of iron are chlorinated in preference to titania at high temperatures, while wilcox4 has claimed the preferential chlorination of titania between 1200" and 1500°C. It has been shown in this paper that preferential chlorination of titania claimed by Wilcox is not likely to occur. Daubenspeck and coworkers5,6 have claimed the preferential chlorination of iron by chlorine or by a mixture of titanium tetrachloride and chlorine between 700° and 1050°C in the absence of carbon. Even when plain titanium tetrachloride is employed as the chlorinating agent, pascaud7 noticed the preferential chlorination of iron and other oxides. The purpose of this paper is to explain from thermodynamical considerations, the various chlorination reactions studied so far. ILMENITE CONSTITUENTS AND THEIR CHLORINATION PRODUCTS Although the general composition of the ilmenite mineral is represented as FeTiO,, most of the ilmenites found in nature have variable quantities of TiO2 (44.6 to 64 pct), FeO (4.7 to 36 pct) and Fe2O3 (6.9 to 28 pct).8 The higher content of ferric iron in ilmenites was attributed by Millerg to the presence of arizonite (Fe2O3.3TiO2). But the X-ray studies by Overholt, Vaw, and odd" have shown that arizonite is a mixture of haematite, ilmenite, anatase, and rutile. Except for the anatase, similar views have been advanced by Lynd, Sigurdson, North, and Anderson8 from magnetic, X-ray, and optical and electron microscope studies. The ilmenite ores can, therefore, be assumed to consist of mineral aggregates of ilmenite, rutile and haematite. From the free energy of formation of ilmenite (FeTiO3), it has been shown by Kelley, Todd, and King11 that ilmenite is stable even up to its melting point (1367°C) and would not undergo decomposition into its constituent oxides. Schomate, Naylor, and Boericke12 have found that in the presence of a reducing agent the iron constituent of ilmenite is selectively reduced. The reaction of chlorine with ilmenite in presence of a reducing agent can, therefore, be synonymous with that of the reaction of chlorine with the constituents of ilmenite, viz., TiO2, FeO, and Fe2O3. Most of the reaction products of chlorination of ilmenite in the presence of reducing agents will be in equilibrium with their dissociation products, depending on the temperature. The titanium tetrachloride is, however, quite stable up to 1500°C due to its covalent nature. The equilibrium for the ferric chloride system has been investigated by Kangro and Bernstorff, 13, schafer14 and Kangro and petersen,15 and the results are summarized in Fig. 1, curves a, b, and c respectively. From these results, it is clear that the ferric chloride disociates as follows: 324° to 700°C FeaCl6(g) ?2FeCl2(c) + Cl2(g) [1] 324°to 900°C Fe2Cl6(g) =2 Fe Cl2 Reaction [I] (curve a) occurs in the forward direction to about 6 pct at 400°C but falls off very rapidly with increase in temperature and beyond 600°C, it is practically negligible, perhaps due to the formation of the stable monomer, FeC13(g). As the temperature is further increased, the amount of FeCl,(g) in-

Jan 1, 1961

By Herbert M. Wilson

We of the employer class represent labor in the social organization and in industry just as truly as do those who labor only with their hands, and, because our labor is chiefly with our brains, the duty is all the more imposed upon us to use those gifts in which we excel in helping steer a clear course through the turbulent waters in which we are now enmeshed. Only their selfish engrossment in the daily tasks they were employed to perform could possibly have permitted the great majority of the intelligent and industrious German people to become terrorized by a handful of the idle, the vicious, and the criminal, whom the elections to the National Assembly showed to be in as pitiful a minority as they are in Russia, in this, and in other countries. It is the leisure unemployment of the I.W.W.&apos;s, the Bolsheviki, and the Sparticans that has enabled them to devote their whole time to a concerted and aggressive struggle against the great majority of those of the world&apos;s workers who are unorganized, and who are therefore even in opposition one to the other. In union there is strength, and this was never better illustrated than by these conditions. The great fallacy of our previous attitude toward social and industrial problems has been the belief that labor, by which we commonly mean organized or physical labor, is something antagonistic to and having a different object in life from that great body of unorganized laborers who work with their brains. Our difficulty has been our lack of will or opportunity to think. The hurry of our daily struggle to earn our livelihood under the nerve-racking pressure of modern civilization has left us no opportunity for quiet thought and study. The physical laborer, and above all the laborer in the mines, on the other hand, has all his hours of toil in which to think over, in all their varied aspects, those problems that concern his immediate, personal well-being. As a result he has arrived at perhaps a more true appreciation of the facts of life in their relation to social and industrial conditions than we. Have we not too readily adopted the view that, as the managers of industry under the direction of capital, it has been our duty to think and act in opposition to labor, rather than to realize that we also are laborers, have like aspirations, and should participate in a free and aggressive solution of these problems rather than leave their solution

Jan 1, 1919

By VILLIAN BRADEN

THIS paper is presented in the hope that it will be instructive in view of the future large expansion of the mining industry in the west-coast countries of South America. There is a more or less general impression that the Spanish-American workman is inferior to the American, but after some years of experience and observation I doubt the correctness of this view. Taking into consideration all the elements which make for efficiency of labor, it has been found, particularly in Chile, that under proper organization native labor yields as much, man for man, and more, dollar for dollar, than in the Western United States. If a manager is willing to accept unreservedly the c costumbres del pais, without combating intelligently and patiently the ones tending to inefficiency, he should expect no better results than he deserves. He must conscientiously insist that a " square deal " be given and exacted; that liquor be excluded from camp as far as possible; that comfortable quarters and other uplifting elements of life be provided; and that the costumbres del pais shall not be over-ridden roughshod. He should also insist upon the gradual and reasonable adjustment of these conditions to the exigencies of the work; and (by no means the least difficult of his tasks) he should select the most competent men to patiently direct and teach the natives in the several departments, and by their own example encourage self-respect and decency. While the Braden mine is by no means as yet operated on a large scale, according to modern rating, it will nevertheless be interesting to note what has actually been accomplished there. An illustrative description of the mines and mill of the\

Oct 1, 1909

By N. A. Stockett

SOUTHEAST Missouri is the largest and oldest lead-producing district in the United States. For the year 1941, the statistical picture of pig-lead production, stated in short tons (partly estimated by the Engineering and Mining Journal) is as follows. [Tons World production 2,000,000 United States production 460.000 Southeast Missouri production 242,000] The consumption of primary lead in the United States in 1941 was approximately 900,000 tons, or almost double the country&apos;s production. The largest previous year&apos;s consumption in the United States was 718,000 tons, in 1926. The largest quantities of lead are used for cable sheathing, storage batteries and white lead. During 1941 tetraethyl lead for auto and aviation gasoline consumed 50,000 tons of lead. The entire lead production of Southeast Missouri is now mined by the St. Joseph Lead Co., whose dominant position as the largest producer in the United States of lead directly from ores is best shown by the fact that in 1941 it produced approximately 31 per cent of the lead production of the United States from its mines in southeast Missouri, where 22,000 tons of ore, averag¬ing over 3.00 per cent lead, is mined per working day. It is known that lead was mined at Mine La Motte, Madison County, Missouri, by Renault in 1723. Other white men and Indians probably did some mining prior to that time. Since 1865, the recorded production to Jan. 1, 1942, shows that the St. Joseph Lead Co. and the various other companies that have operated in St. Francois County mined lead ore, which, after milling and smelting losses produced 5,00,000 short tons of pig lead. About 95 per cent of the present lead production of Southeast Missouri is mined in St. Francois County. The northern part of this area is 60 miles south of St. Louis. The remainder of the lead is obtained at Mine La Motte, about 25 miles southeast from the center of the producing area in St. Francois County. PROSPECTING In this district, most of the ore is discovered by surface and underground diamond drills and by prospect drilling underground with rock drills. Each 2-ft. length of the cuttings from these Jackhamer prospect holes is assayed for lead. These holes are marked and the records are entered on maps. It has been found that close drilling--100-ft. centers of holes, and sometimes less-is necessary in order to locate most of the smaller commercial ore bodies, many of which previously had been missed by drilling the areas with holes spaced 200-ft. centers or more.

Jan 1, 1943

By P. B. Butler

IN common with others, the zinc industry found itself after the war largely over-capitalized, a condi-tion which still exists notwithstanding that Tri-State production has doubled since prewar days. This is partly due to the abnormal war demands and partly because of the war impetus given to research, a stim-ulus that because of its success has persisted (and probably will persist) constantly since then. Improved practice and metallurgy resulting from research are today responsible for an increased pro-duction in the Tri-State district of 15 per cent over the practice of five years ago, and the giant strides in this respect in the western states together with the more moderate advance in the Tri-State district has thrown out of equilibrium the more or less balanced production of before the war and production has con-sequently gained on consumption, a condition resulting in rapidly narrowing profits in the Tri-State field, where the present average cost is actually greater than the price received for our product. Despite this condition, no thinking person will de-plore the cause or means used to achieve a greater production and, as this progress is merely the economic application of intelligent thought, it follows that equal effort and thought may be expected to produce the remedy. It has been suggested that the practical application of research has resulted in less need for man-power and consequently in the lessening of employment to common labor and to engineers. I cannot think that such is the case although personally I have received more ap-plications for employment during the last two years than ever before. But when one considers the strides production of all commodities has taken, it is difficult to reconcile this immense development with the possible increase in pop-ulation especially in view of our stringent immigration laws. Whether or not improved industrial methods are responsible for the lessening of employment the ques-tion as to the wisdom of such improvement is hardly debatable. While the Tri-State district of Oklahoma, Kansas and Missouri continues to be the leading factor in the zinc¬mining industry, gradually lowering prices during 1925 and 1926 and a. decided drop during 1927, have de-creased its production almost 20 per cent, this tonnage having largely been replaced by western concentrates.

Jan 4, 1928

By R. B. Kelly, Paul Martin

Central Texas added 76 producing oil and gas wells during the year, abandoned 378 wells in the same period, and produced 10,359,905 bbl. of oil in the 12 months under consideration. The oil production represents a decline of only 3 per cent as compared to 1934, but it must be remembered that much new production was added during the year. The activity in new work centered in Frio, Bexar, Williamson and Cald-well counties, with development in the Pearsall, Von Ormy and Byersville fields taking first importance. New discoveries in 1935 were confined to Pearsall area of Frio County and an extension to the Darst Creek field in Guadalupe County. The Red Lake field, in eastern Freestone County, proved itself of importance from the standpoint of a gas reserve but no oil production has yet been obtained. In Bexar County, the Von Ormy field, in which the discovery well was drilled early in 1934, completed 22 oil producers during the year. (A map of Central Texas showing location of oil and gas fields was published in Volume 114 of the A.I.M.E. Transactions.) New Fields Pearsal1.—The Amerada Petroleum Corporation, in developing its 60,000-acre block in Frio County, has definitely proved the existence of commercial oil production in four separate horizons; namely, the Navarro, the Austin Chalk, the Buda and the Georgetown. The discovery well, a two million cubic foot gas well, was tompleted in 1934. A test of the Trinity sand at 10,050 ft. found salt water but later was plugged back and finished as an oil well in the Navarro sand. Most recent of their discoveries has been in the Austin Chalk at a depth of 5666 ft., where a 24-hr. gage through 1-in. choke showed 2640 bbl. of pipe line oil. The oil has a gravity of 28.0" A.P.I. and is brownish in color. Because of lack of pipe lines in the area, the wells are produced only for short periods of time, and it is predicted that development will be slow until the district is entered by pipe line purchasing companies. Von Ormy.—In March, 1934, Umbren et al. completed their Wentz

Jan 1, 1936

By Gerald Sherman

IN the southern field of the anthracite region of Pennsylvania, many of the coal seams dip at angles of 40° to 50° from the horizontal. For transportation purposes, "tunnels" are driven across the coal measures and, occasionally, "rock gangways," beside the seams and parallel with them. The use of gangways driven in country rock appears to be increas-ing, as they avoid the maintenance&apos; of long gangways in coal, which eventually are driven to the colliery boundaries, and permit mining from a number of intermediate blocks without interference. The rock consists of slates or sandstones of moderate hardness, which may range into very hard, highly siliceous, fine-grained conglomerates. In this distinctly bedded formation,&apos; the direction of the heading, whether parallel with or across the structure, makes it necessary to distribute the drill holes in a different pattern to break the ground, but does not change loading conditions. In 1932, practically all the mucking was done by hand, and it was the established custom to use four men on two drills for drilling and breaking the ground, and five for loading it, out. A driver and mule was needed in addition, to assemble the rock cars at a siding or branching track in the rear, pending their final disposal. This might occupy the driver&apos;s whole time, or if the length of haul were short, he might be able to do other useful work. It was thought possible in 1932 to reduce the cost of driving such headings in rock by mechanical loading, and to investigate this subject a scraper loader was used in a section of tunnel then being driven. Opera-tions while driving 195 ft. of this tunnel using a scraper loader were care-fully observed. Time studies were made of the loading, and records made of the routine of breaking ground, but not in such detail. Tunnels or gangways in the colliery are 7 ft. high above the rails, by 10 ft. wide, which requires a minimum of 8 ft. in height, broken to allow for rails and ties. This cross section is of sufficient size to permit the use of any one of several types of power loaders, but for this demonstration if was found most convenient to use a scraper loader.

Jan 1, 1936

By Paul Martin, R. B. Kelly

Central Texas added 76 producing oil and gas wells during the year, abandoned 378 wells in the same period, and produced 10,359,905 bbl. of oil in the 12 months under consideration. The oil production represents a decline of only 3 per cent as compared to 1934, but it must be remembered that much new production was added during the year. The activity in new work centered in Frio, Bexar, Williamson and Cald-well counties, with development in the Pearsall, Von Ormy and Byersville fields taking first importance. New discoveries in 1935 were confined to Pearsall area of Frio County and an extension to the Darst Creek field in Guadalupe County. The Red Lake field, in eastern Freestone County, proved itself of importance from the standpoint of a gas reserve but no oil production has yet been obtained. In Bexar County, the Von Ormy field, in which the discovery well was drilled early in 1934, completed 22 oil producers during the year. (A map of Central Texas showing location of oil and gas fields was published in Volume 114 of the A.I.M.E. Transactions.) New Fields Pearsal1.—The Amerada Petroleum Corporation, in developing its 60,000-acre block in Frio County, has definitely proved the existence of commercial oil production in four separate horizons; namely, the Navarro, the Austin Chalk, the Buda and the Georgetown. The discovery well, a two million cubic foot gas well, was tompleted in 1934. A test of the Trinity sand at 10,050 ft. found salt water but later was plugged back and finished as an oil well in the Navarro sand. Most recent of their discoveries has been in the Austin Chalk at a depth of 5666 ft., where a 24-hr. gage through 1-in. choke showed 2640 bbl. of pipe line oil. The oil has a gravity of 28.0" A.P.I. and is brownish in color. Because of lack of pipe lines in the area, the wells are produced only for short periods of time, and it is predicted that development will be slow until the district is entered by pipe line purchasing companies. Von Ormy.—In March, 1934, Umbren et al. completed their Wentz

Jan 1, 1936

By Wallace Ralston

DuRing the year of 1937, the East Texas district produced 211,194,467 hbl. of oil and marketed more than 22,329 million cu. ft. of gas; 3377 oil and gas wells were completed. During this same period 106 exploratory wells were drilled, discovering three new oil fields and one gas-distillate field. Fields East Texas Field.—The East Texas field again led the district as to production and number of wells completed. During the year, 2420 oil wells were completed, making a total of 24,382 producing wells, which produced 171,336,854 bbl. of oil, for a total of 1,156,352,834 bbl. since the beginning. During the year the average bottom-hole pressure dropped 49 lb., making the average bottom-hole pressure 1119 lb. Approximately 3500 wells are making salt water, 20 per cent of them making over 80 per cent of the water. During the month of December, the daily average production of salt water was 119,000 barrels. Talco Field, Titus and Franklin Counties.—The Talco field produced 9,780,948 bbl. of oil during the year, from 637 wells. During the year 472 wells were completed. All of the wells are pumping and 241 are making salt water. This field has followed a normal development and did not exceed the estimated number of acres reported last year. Rodessa Field, Cuss and Marion Counties.—The Rodessa field was extended about 13 miles southwest into Marion County, which added approximately 4000 acres to the field. During the year 260 wells were completed, making a total of 416 producing wells, which produced 12,646,-970 bbl. of oil. The author was unable to obtain figures for the amount of gas produced. The field has two gasoline plants, which had a daily average of 16,558,000 cu. ft. of gas during December, averaging 0.83 gal. per M cu. ft. As of Jan. 1, 31 wells were making salt water. The bottom-hole pressure varies greatly, depending upon the pay from which the well is producing. The average bottom-hole pressure from the Young

Jan 1, 1938