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By Corliss R. Kinney

Since the first atomic bomb exploded over Japan, a great deal of speculation has been published about the use of atomic energy instead of coal for the production of power. Atomic energy, in time, may displace coal for this purpose, but atomic energy will not displace coal in supplying chemical raw materials to the rapidly expanding carbon-chemicals market. Modern civilization demands large quantities of carbon compounds and the logical source of many of these is coal. Consequently, many progressive operators are considering the possibilities of the utilization of coal as a chemical raw material as never before. Furthermore, the demand for clean, smokeless, and ashless fuels will continue to increase and the only way to handle coal under those conditions is to take it apart, just as crude petroleum is taken apart. One can readily imagine where the petroleum industry would be now if it had insisted on selling customers only crude oil, perhaps emulsified with a little salt water to correspond to the moisture and mineral matter in raw coal. The time seems to be coming at an accelerated Dace when mine operators will find that competing for a highly selective fuel market by producing a larger tonnage at smaller cost will be less profitable than to increase the value of a smaller tonnage many fold by producing something more valuable to industry and civilization than raw coal. For example, about 750,000 tons of carbon black selling for $50 to $60 per ton was produced in the United States in 1945. This tonnage is insignificant compared with the total production of coal in the United States, but a very tidy tonnage, together with the coal necessary to operate the process, for any mine operator fortunate enough to obtain a method of producing a better carbon black from coal. From the point of view of tonnage, the manufacture of coke of various kinds and its by-products is at present the most important source of carbon chemicals from coal. Nearly 20 per cent of the coal mined in this country is used for this purpose. A large proportion of the coke is used for the production of iron and steel, but even in this operation a considerable part of the coke is used for a chemical purpose; that is, the reduction of the ore to metallic iron. In addition, large quantities of coke are used in manufacturing many important products that find their way into the market. Possibilities of Acetylene One of the important chemicals manufactured from coke is calcium carbide, from which many products are made. One of these is acetylene. This hydrocarbon can also be manufactured from natural gas or from waste oil-refinery gas and these industries will probably offer competition for the manufacture of acetylene. Coke-oven gas can be used for making acetylene and should receive consideration

Jan 1, 1947

By C. M. Shigley

The record of the largest magnesium plant in the country utilizing sea water as a primary raw material stands as another victory in the struggle for large-scale production of pure chemical elements from the oceans. Bromine was the first element to be economically and commercially recovered when, in 1933, a six million pound per year unit was built on the Atlantic Coast near Wilmington, North Carolina, by the Ethyl-Dow Chemical Co.' The bromine was reacted with ethylene to produce ethylene dibromide, a necessary associate of tetraethyl lead in ethyl antiknock fluid. Within eight years that plant was doubled and redoubled, and another large unit was put into operation at Freeport, Texas, taking bromine from the Gulf of Mexico. In 1940, in fortunate anticipation of the impending demand for magnesium and the limitations of the production from natural brines, the Dow Chemical Co. turned again to the sea, and designed and erected a plant at Freeport to produce 18,000,000 lb. of magnesium per year from sea water.2 In March 1941, two months after the new plant had been put into successful operation, construction of an 18,000,000-lb. Government-financed addition was started. Late in 1941, as a part of the $400,000,000 defense program intended to produce 600,000,000 to 700,000,000 lb. of magnesium per year, Dow was asked to build and operate for the Government a 72,000- ooo-lb. plant near its original plant at Freeport. Within a few days after the Japanese made their attack at Pearl Harbor, preparation of a site was started at Velasco, Texas, for the construction of the Texas plant of the Dow Magnesium Corporation—the largest known magnesium plant utilizing sea water as its raw matcrial. Less than six months after the first piling was driven, urgently needed magnesium was in steady production. Five months later, the plant had exceeded its rated capacity. It remained above rated production until the general magnesium curtailment was applied to Government-owned plants in September 1944. Credit for the construction and operation record of the Dow magnesium plant must be divided among the efforts of a very determined group of men, an extremely favorable location, and a simple process. It is with the two latter aspects of the plant that this article will deal. The site for the new enterprise was chosen near Velasco, Texas, on property bordering the Brazos River at a point approximately 6 miles inland from the original magnesium plant and 7 miles inland from the Freeport Harbor on the Gulf of Mexico. This location was far enough away from the operating units to reduce both interference from construction and the vulnerability of closely bunched manufacturing operations to the then feared air attack. Yet the distance inland was not too great for the economical construction of a barge canal from the harbor to serve both the transportation of raw

Jan 1, 1949

By W. O. Philbrook, K. Natesan

The oxidation kinetics of spherical pellets of zinc sulfide made from Santander concentrates were studied using a thermogravimetric technique. The experiments covered a temperature range-. of 740" to 102O°C, 0-N mixtures varying from 20 to LOO pct O2, and pellet diameters between 0.4 and 1.6 cm. Mathematical models were formulated to Predict the reaction rate on the assumption that a single transport or interface reaction step was rate -controlling. Analysis of the data indicated that the process of oxidation was predominantly controlled by transport through the zinc oxide reaction-Product layer. ROASTING processes, which are reactions between solids and gases, are very important because they are employed in the production of a number of basic metals. These processes are highly complicated, and one needs to consider the transport phenomena of heat and mass between the solids and gases in addition to the kinetics of various chemical reactions involved. Because of such complications there is a lack of knowledge concerning the rate-limiting factors, which may strongly depend on temperature, particle size, gas composition, and solid structure. The oxidation of zinc sulfide, which is of commercial importance in zinc production, falls into this class of reactions. The major goal of this work was to elucidate the roles played by different process variables, such as reaction temperature, gas composition, pellet size, and pellet porosity, on the kinetics of oxidation of single pellets of zinc sulfide. Roasting of zinc sulfide single particles has been a subject of both experimental and theoretical investigations.&apos;-&apos; The reaction is exothermic and may be considered to be irreversible. Such a reaction has been found to proceed in a topochemical manner. In other words, as the reaction proceeds, a progressively thicker outer shell of zinc oxide is formed, while the inner core of unreacted sulfide decreases. It has been found experimentally, both in the present work and in the previous investigations,1-9 that the particle retains its original dimensions and the process requires transport of gaseous oxygen across the porous product layer for continued reaction. The reaction may be represented by ZnS(s) + 3/2 O2(g) = ZnO(s) + SO2(g) [1] The solid product considered here is only zinc oxide, since the diffraction patterns of zinc sulfide pellets oxidized partially at &apos;798" and 960°C showed K. NATESAN, Junior Member AIME, formerly St. Joseph Lead Fellow, Department of Metallurgy and Materials Science, Carnegie-Mellon University, Pittsburgh, Pa., is now at Argonne National Laboratory, Argonne, Ill. W. 0. PHILBROOK, Member AIME, is Professor of Metallurgy and Materials Science, Carnegie-Mellon University. This paper is based on a them submitted by K. NATESAN in partial fulfillment of the requirements for the Ph.D. degree in Metallurgy and Materials Science at Carnegie-Mellon University. Manuscript submitted December 2, 1968. EMD lines corresponding to original zinc sulfide and the newly formed zinc oxide. OXIDATION MODEL The generalized model for gaseous oxidation of zinc sulfide is illustrated in Fig. 1. This depicts a partially oxidized sphere of zinc sulfide in a gas stream surrounded by a laminar film of gas. The spherical sample of zinc sulfide of unchanging external radius r0 is suspended in a flowing gas stream of total pressure PT and composition specified by the partial pressures of the individual components. Partial pressures of the gaseous species in the bulk gas phase, at the exterior surface of the pellet, at the ZnS/ZnO interface, and at equilibrium for Reaction [I] are identified by the superscripts b, o, i, and eq, respectively. The overall reaction involves the following ~te~s:&apos;~&apos;~&apos; Step 1. Transfer of reactant gas (oxygen) from the bulk gas stream across the gas boundary layer to the exterior surface of the pellet and the reverse transfer of the product gas (sulfur dioxide). Step 2. Diffusion and bulk flow of oxygen from the pellet surface through the product shell (ZnO) onto the ZnS/ZnO interface and the reverse transfer of sulfur dioxide. Step 3. Chemical reaction at the interface, which results in consumption of oxygen gas and generation of sulfur dioxide gas and heat; at the same time the _________ PARTICLE SURFACE / x^^^^n^X / MOVING INTERFACE core-----/ sJSNxy " /T^T^02 \ V\V$\ ^NWX/ "*/— GAS BOUNDARY x. \\ZnO SHELLV/ / \^ . / &apos; ^ BULK GAS --------N_______ _____,------p£ w \ P« / (f> \ / a \ <i) / <----------------- _(o) ^^--------------(b) °- pso, pso2 ro ri 0 ri ro RADIAL POSITION Fig. 1—Generalized model for oxidation of a sphere of zinc sulfide.

Jan 1, 1970

By S. W. Kennedy, M. Cohen, L. D. Calvert

A high-temperature X-ray diffraction method has been used to study the composition and the kinetics of formation of oxide scales at 800 °C on iron and pure iron-nickel alloys containing 25.6, 75, and 84 pct Ni. This technique has been combined with chemical analysis, and metallographic examination, and determination of weight-gain time curves. The 75 and 84 pct Ni alloys form a three-layer scale consisting of porous NiO next to the metal, a spinel layer, and a -Fe203 on the outside. The 25 pct Ni alloy produces a scale of spinel and Fe,O,, in which, however, traces of FeO and NiO are observed near to the metal. On all the nickel alloys the Fe20, is orieqted with the (107) plane parallel to the surfaces. The exposed surface of the Fe20, is in the form of needles whose axis is perpendicular to the specimen surface. Although the alloys show nonuniform oxidation rates as determined from weight-gain measurements, the X-ray data indicate that the total scale and individml scale layers grow uniformly and parabolically. Deep subscale formation is observed in the 25 pct Ni alloy only. This appeared to be associated with cracking of the scale and penetration of the oxygen along the grain boundaries. ALTHOUGH film formation has been investigated by high-temperature electron-diffraction techniques, for example by Gulbransenl and Hickman,&apos; there have apparently been no investigations of scaling by methods permitting study of the scale during formation at the reaction temperature. Methods involving quenching of scales are based on the working assumption that no significant changes take place on cooling. In general, however, compounds may disproportionate, and the different thermal expansions of constituents may cause disruption of the scale on cooling. In particular, some scales cannot be quenched without spalling. These difficulties are avoided by X-ray diffraction examination at the temperature of formation. High-temperature diffraction procedures also provide a method of determining the kinetics of formation of each phase separately in a multicom-ponent scale. The scaling of binary iron-nickel alloys Containing up to 30 pct Ni at a temperature of 800°C has been studied by Benard and Moreau using cooled specimen~,~ whilst Foley, Druck, and Fryxel14 made an electron-diffraction study of cooled oxide films formed on an iron 42 pci Ni alloy. In the present work the scaling of three iron-nickel alloys containing 25.6, 75, and 84 pct by weight of nickel, at 800°C in oxygen at atmospheric pressure was investigated by X-ray diffraction techniques using a Norelco Geiger-counter diffrac-tometer. The oxidation of iron was investigated for comparison. In addition normal metallographic examinations and chemical and X-ray analyses were made, and weight-gain time curves obtained. EXPERIMENTAL Materials Used—The analyses of the alloys were as follows: Percent by Weight Nickel 25.6 pct 75.4 pct 83.2 pct Aluminum 0.004 None found 0.002 Cobalt — 0.05 0.05 Chromium — — — Silicon — 0.01 None found Carbon All less than 0.05 pct The chemical analysis of the iron was: Al— 0.002 i 0.001 pct, C—0.007 pct, Cr less than 0.001 pct, Cu—0.002 ± 0.001 pct, Mn—0.003 ± 0.001 pct, N—0.0002 pct, 0-0.013 pct, P—less than 0.0002 pct, Pb—not detected, S—0.0017 pct, Si—0.0095 pct, Sn—none detected. This iron was the same as that used to make the alloys and was obtained from the same source-Vacuum Metals Corp. One specimen of pure iron from The British Iron and Steel Research Association was used for preliminary investigation. Specimens were machined to shape from cast rod, polished (the final polish being with 600 Sic paper), degreased in trichlorethylene, washed, and etched. The etching and neutralizing procedure adopted by

Jan 1, 1960

By Bernard G. Carbajal

The dielectric properties and thermal stability of glow-discharge polytnerized films of styrene, chloro-benzene, and other organics and photoresist filrns are presented. Variations in the glow-discharge polymerization procedure are related to thermal stability. Thermal treatwzents to improve the dielectric properties of both positive (A2 340) and negative (KMER) photoresists are given. THIS study of the dielectric properties of thin organic polymer films is part of a program to investigate the electronic applications of organic materials. Thin organic polymer films have been produced in an ac glow discharge,13 with a low-energy electron-beam process,4 and in an rf dicharge. A process has been developed during the course of this program for forming thin organic polymer films in a dc glow discharge. These glow-discharge polymerized (GDP) films exhibit some useful dielectric and insulative properties. Variations in the properties of the GDP films can be induced by changes in the source material (monomer) andor in the conditions of the glow discharge. Thin organic polymer films can also be produced from typical positive and negative photoresists. Some variations in the properties of the photoresist films can be induced by suitable post-application treatments such as thermal crosslinking. The properties of interest in this study are dielectric constant, dielectric strength, resistivity, and thermal stability. POLYMER FILM PREPARATION I) GDP Films. The GDP films were prepared in a dc glow discharge in an atmosphere of organic monomer vapor. The details of the glow-discharge procedure have been presented previously.6 Briefly, under the influence of a dc glow discharge organic vapors can be polymerized in the vapor phase and the resultant polymer (GDP film) deposits on and in the vicinity of the cathode. Substrates placed behind a screen cathode can be uniformly coated over all exposed areas. Pattern definition can be achieved using normal mask stencil techniques. Table I presents the pertinent parameters in the preparation of GDP styrene. Conditions of Forrrzation of GDP Styrene. The rate of deposition for GDP films was monitored using a current-time integrator. The thickness of the deposited film for a given set of experimental conditions was a function of the current-time integral. The fifth row in Table I is a compilation of the deposition rate of GDP styrene films. Other organic monomers behave in a similar fashion. With the exception of the highly halogenated saturated hydrocarbons, all organics subjected to the conditions of the glow discharge form GDP films. 11) Photoresist Films. Photoresists are normally recognized to exist in two forms, a low molecular weight, soluble polymer form (A) and a high molecular weight, crosslinked insoluble form (B). Typical negative photoresists are applied in the low molecular weight form A and converted to the high molecular weight form B by the action of light. (Positive photoresists are applied in form B and converted to form A by the action of light.) Eastman Kodak Metal Etch Resist (KMER) has been chosen as a typical negative photoresist. Polymer film samples were prepared in the same configuration used for GDP films. The KMER was applied in the usual fashion using a 120°C drying step (infrared-lamp heating) and a 180°C post-bake. Care must be taken to completely remove the solvent in the drying step and to properly develop and postbake to exposed photoresist. If the photoresist film is not properly dried and postbaked, severe blistering and peeling will occur during subsequent elevated-temperature exposure. Thickness can be controlled by varying the viscosity of the form A photoresist and the spin rate at application. AZ 340 was chosen as a typical positive photore-

Jan 1, 1967

By T. M Morris

THE rate of flotation of solid particles determines the percentage recovery of these particles which can be obtained during a given time interval. It is an established fact that the recovery is greatest in the fine sand size range and falls off on either side of this size range. It is also a fact that the history of the development of concentrating devices has been marked by a desire to recover the small particles: tables were developed to treat material too fine to recover in jigs; flotation recovers material too fine to be recovered on tables. As our ores become more complex and require finer grinding, a greater proportion is in the slow-floating size range. It is therefore of economic importance that the effect of size of particle upon rate of flotation be studied. Many studies have been made along this line. The present investigation attempts to quantify the rate of flotation by means of a rate equation, and then compares the effect of size upon the rate of flotation. It was found that the flotation rate constant increases with increase in diameter of particle in the size range smaller than the optimum size particle. The flotation rate constant decreases with an increase in diameter of particle in the size range coarser than the optimum size particle. This suggested two different actions taking place, and these are discussed. Suggestions for further work in order to improve the flotation rate of both fine and coarse particles are made. The usual method of expressing rate is to plot cumulative percent recovery vs time. If we knew the equation of this kind of curve we could replot it as a straight line, and the slope of the line would be an index of the magnitude of the flotation rate. It is easier to compare straight lines than curves. The basis used for obtaining the equation of the recovery vs time curve is the law of mass action. This law states that the "rate of a chemical reaction is proportional to the &apos;active masses&apos; of the reacting substances present at any given time." This, of course, implies a constant temperature. We can modify this for our use by using the term flotation reaction instead of chemical reaction and the term floatable particle instead of active masses. dC Thus----— kc [1] where C denotes concentration of particles, t denotes time, k denotes a proportionality constant. If the exponent of C is 1, then we have a first order rate reaction. If the exponent of C is 2, then we have a second order rate reaction. For a first order rate reaction, we obtain, after integration, where k is again a proportionality constant and has the dimension of the reciprocal of time. C, is the original concentration or weight or percentage of floatable particles. C, is the concentration or weight or percentage of floatable particles remaining in the flotation cell after time t. If all particles of the mineral to be floated were capable of floating we could take C, as 100 and C, would be 100 - R, where R is the cumulative percentage recovery of mineral at time t. But it is not usual for all of the particles to be capable of floating, because of surface oxidation, etc. Therefore, we must introduce a factor x which is the percentage of un-floatable mineral. Hence the first order equation is It has been proposed by various workers1-&apos; that this equation describes the flotation rate. More recently N. Arbiter4 states that a second order rate equation fits the recovery vs time curve more closely than does a first order rate equation. Morris- as discussed the evidence presented for this statement. It has been concluded that the first

Jan 1, 1953

By T. M. Morris

THE rate of flotation of solid particles determines the percentage recovery of these particles which can be obtained during a given time interval. It is an established fact that the recovery is greatest in the fine sand size range and falls off on either side of this size range. It is also a fact that the history of the development of concentrating devices has been marked by a desire to recover the small particles: tables were developed to treat material too fine to recover in jigs; flotation recovers material too fine to be recovered on tables. As our ores become more complex and require finer grinding, a greater proportion is in the slow-floating size range. It is therefore of economic importance that the effect of size of particle upon rate of flotation be studied. Many studies have been made along this line. The present investigation attempts to quantify the rate of flotation by means of a rate equation, and then compares the effect of size upon the rate of flotation. It was found that the flotation rate constant increases with increase in diameter of particle in the size range smaller than the optimum size particle. The flotation rate constant decreases with an increase in diameter of particle in the size range coarser than the optimum size particle. This suggested two different actions taking place, and these are discussed. Suggestions for further work in order to improve the flotation rate of both fine and coarse particles are made. The usual method of expressing rate is to plot cumulative percent recovery vs time. If we knew the equation of this kind of curve we could replot it as a straight line, and the slope of the line would be an index of the magnitude of the flotation rate. It is easier to compare straight lines than curves. The basis used for obtaining the equation of the recovery vs time curve is the law of mass action. This law states that the "rate of a chemical reaction is proportional to the &apos;active masses&apos; of the reacting substances present at any given time." This, of course, implies a constant temperature. We can modify this for our use by using the term flotation reaction instead of chemical reaction and the term floatable particle instead of active masses. dC Thus----— kc [1] where C denotes concentration of particles, t denotes time, k denotes a proportionality constant. If the exponent of C is 1, then we have a first order rate reaction. If the exponent of C is 2, then we have a second order rate reaction. For a first order rate reaction, we obtain, after integration, where k is again a proportionality constant and has the dimension of the reciprocal of time. C, is the original concentration or weight or percentage of floatable particles. C, is the concentration or weight or percentage of floatable particles remaining in the flotation cell after time t. If all particles of the mineral to be floated were capable of floating we could take C, as 100 and C, would be 100 - R, where R is the cumulative percentage recovery of mineral at time t. But it is not usual for all of the particles to be capable of floating, because of surface oxidation, etc. Therefore, we must introduce a factor x which is the percentage of un-floatable mineral. Hence the first order equation is It has been proposed by various workers1-&apos; that this equation describes the flotation rate. More recently N. Arbiter4 states that a second order rate equation fits the recovery vs time curve more closely than does a first order rate equation. Morris- as discussed the evidence presented for this statement. It has been concluded that the first

Jan 1, 1953

By J. D. Meakin, H. G. F. Wilsdorf

An etching technique.has been used to investigate the dislocation structure of deformed @-brass single crystals. Isolated single ended pileups have been observed, and it is shown that, in certain cases, the configurations of such pileups agree with theoretical predictions. Many discrete pileups within heavily deformed regions have also been detected and the influence of surrounding dislocations on these groups are reported and discussed. Divergences between the experimental and theoretical spacings in the isolated pileups and the origin of the stress maintaining the pileups are discussed. THE spatial configuration of a linear array of identical dislocations has been evaluated theoretically by Eshelby, Frank, and Nabarro.&apos; Of particular interest is the equilibrium spacing of a series of dislocations under a uniform shear sti-ess when the leading dislocation is held fixed in the lattice; such an array is termed a single ended pileup. Eshelby, Frank, and Nabarro&apos; found that an explicit analytical solution to the problem of n dislocations in a pileup is not possible, but they were able to derive approximate formulae applicable under various limiting conditions. An alternative method of determining the equilibrium configuration was proposed by Leibfried and Leibfried and Haasen in which the discrete dislocations are replaced by a continuous dislocation density. This technique was used by Head and Louat to solve in first approximation, a number of problems of particular interest, eg., single and double ended pileups. Head has also solved numerically a number of specific configurations involving up to six dislocations. Recently Kuhlmann-Wilsdorf has obtained numerical solutions for single-ended pileups containing between three and seventy dislocations, thus making possible a comparison between appropriate experimental results and accurate theoretical values. The considerable use of the pileup concept in theories of plastic flow has stimulated a number of attempts to observe such arrays experimentally. There is of course considerable intrinsic value in revealing an isolated pileup because a direct check on the elastic theory of dislocations then becomes possible. The only technique generally applicable for studying pileups in bulk metal specimens is selective etching of the point of emergence of individual dislocations. Confining our attention to etching studies which have revealed pileups, the earliest reported work

Jan 1, 1961

By Charles Stuart

A PAPER on this subject can cover but a limited range. A thorough visualization of the subject would contemplate a comparative analysis of haulage machines and batteries of various types; the relationship of the storage-battery locomotive to other types of mine haulage should be considered and limiting factors in each case should be carefully developed. This paper will briefly deal with these factors. So far as the writer has been able to determine, the first storage-battery locomotives for mine haulage were manufactured in 1897 or 1898 and were tried out in the Pocahontas coal field, but they were not sufficiently satisfactory to justify their continued use. Battery explosions were frequent and caused serious damage to the wiring, electrical equipment, and the clothing and bodies of the motormen. Sulfuric acid was used as the electrolyte. Experiments were then conducted with locomotives bearing reels of flexible cable through which connection between the motors of the locomotive and the trolley wire was maintained. At first, these reels were turned by hand. Later, the reels were revolved by contact with the wheels of the locomotive, being raised out of contact with the wheels, by a lever, when necessary. About 1902, the plan of operating the reel, by chain and sprocket wheels, from one of the locomotive axles, as is still the practice, was devised. The popular floating motor-driven reel had its inception in the Pocahontas fields prior to 1906. The maximum radius of operation of the reel-type locomotive is about 500 ft. (150 m.) from point of connection with trolley wire. This is ample for room work and certain entry work, but the need for a machine that would operate entirely independently of the trolley wire was so great that, with the development of the storage battery, renewed efforts were made to manufacture a successful storage-battery locomotive. About 1908, the gasoline locomotive was introduced. In spite of many objections to this type of machine for such work, the fact that hun¬dreds of these machines were purchased was proof of the need for a machine operating independently of the trolley.

Jan 1, 1922

By A. N. Chirico

This paper reviews the three major distillation processes: multiple effect (LTV) evaporation, multi-stage flash distillation and vapor-compression forced circulation evaporation. Scale preventative measures are discussed for all saline water applications. Operational data is presented on the Freeport, Texas, demonstration plant, which is the first government facility to produce one million gallons per day of fresh water for a municipality. There has been much publicity concerning the water crisis that confronts many peoples today. There is little doubt that the arid regions - which include the Middle East, parts of Africa and the Caribbean — have suffered to no slight extent for the lack of this most precious commodity. But what about our own country? Government experts have extrapolated demands and flatly predict that by 1980 we will be faced with a shortage of 80 billion gal per day. The validity of this prediction has been disputed by others; however, it appears certain that there will always be a natural abundance in some areas, a shortage of supply in other areas. Distributing our total natural water resource equitably would be impossible. Transmission of water by means of aqueducts can be an expensive undertaking. The controversial Feather River Project in Calif. is an example. The estimated cost for this venture is a staggering three billion dollars. As our population continues to increase and our standard of living rises, agricultural and industrial requirements will be proportionate. What can be done to avoid a crisis? We can conserve and use our water for industrial and irrigation purposes more judiciously: we can attempt to eliminate pollution of our natural resources from sewage and industrial wastes; we can develop, while there is time, saline water conversion processes for the massive production of low cost fresh water. The scope of this paper will be limited to only the distillation type processes that are commercially feasible. The first step in making potable water is to find a source of raw material. An inexhaustible supply is provided by oceans in coastal regions, but the supply of water is more critical in the inland communities of our country. The source of raw material in these. regions is brackish well water and this must be utilized. There is a significant process difference when handling brackish water compared to seawater and this brings out an important fact: No single conversion method can be universally applied to solve all the water problems. Composition of the raw water and degree of distillate purity are factors which must be considered before a particular process is selected. Local conditions at the plant site, fuel costs, labor costs, disposal facilities, etc. are other equally important factors which must be evaluated. WATER CONVERSION PROCESSES Conversion processes commercially feasible today are: 1) multiple effect evaporation, 2) multiple flash distillation, 3) vapor compression distillation and 4) electrodialysis. The first three are distillation processes which take potable water out of the raw water, while the fourth is a membrane process which takes out the salt. In addition to the above there are a good number of other promising methods for production of potable water, many of them in the basic research stage. Freezing is another promising process with commercial potential. This process hinges upon the formation of ice crystals which are free of salt occulsions. Separation and washing of the crystals are problems that must be solved before this process can be considered commercially feasible. Freezing processes have several advantages mostly attributable to the low temperature of operation. This low temperature reduces the scaling and corrosion problems encountered in higher temperature operations. Several different freezing processes are being considered and will be tested in the pilot plant at Wrightsville Beach. One process is a flash freeze process, a second uses a secondary refrigerant such as butane for freezing, and a third process employs a secondary refrigerant particularly controlled to produce large ice crystals. Of the above processes, only the distillation processes are reliable when water of high purity is re-

Jan 1, 1963

By O. D. Gonzalez, R. A. Oriani

The migration of hydrogen and of deuterium dissolved in a iron and in nickel induced by an applied electrical potential has been measured over a range of temperature. In all cases the intevstitial solute migrates to the cathode. The deduced charges of transport are positive, independent of or slightly dependent on temperature, and markedly larger for the beavier mass. These results are interpreted as showing predominating momenlum transfer between electron holes and the acticated complex of the elementary diffusion act. THE migration of components of a metallic system under the action of an applied electrical potential is called electromigration or electratransport. This phenomenon has been known since 1861 and is becoming of increasing interest to metal scientists because of the opportunity it offers to explore the connections between mass transport and electron transport. Until recently, reliable data have been very scarce because of the difficulties inherent in the measurements. In addition, theoretical understanding has been either nonexistent or rudimentary and at present this situation is only moderately improved. Whereas the prevalent notion had been (and is still widely held) that electromigration directly reflects the state of ionization of a component in its equilibrium state in the metal, it is now becoming clear that the major, if not the sole, factor is the momentum transfer between the charge carriers, themselves in motion because of the applied field, and the metallic components in their activated state. It becomes important therefore to obtain reliable data over a range of temperature on electrornigration in systems where only one component moves, that is, either in pure metals (vacancy motion) or in interstitial solid solutions. Our choice of systems was dictated by our measurements&apos; of the Soret effect in solid solutions of hydrogen and deuterium in iron and nickel. Indeed, the main reason for making measurements on electromigration at all is that we suspected a mechanistic connection between thermal diffusion and electromigration. In our former paper&apos; we proposed that what is common to both phenomena is the momentum transfer between the charge carriers in the metal and the atom as it jumps from one equilibrium position to another. In Soret diffusion, however, there is in addition the dissipation of the energy of the jumping atom via pho-nons. We have since found that similar ideas for this interconnection have been developed by Fiks.2 In the present paper we will discuss in more detail our understanding of the mechanism of electromigration itself, but we turn first to a presentation of the experiments and results. EXPERIMENTS AND RESULTS Let us consider a metallic system in which only one component, m , can diffuse at the temperature in question, and to which are applied simultaneously an electrical potential gradient, grad cp, and a chemical potential gradient, grad p,. One may write3 for the material flux Jm and the electronic charge flux Je by applying the condition, grad = 0, to Eq. [I] and evaluating grad(um/T) for the isothermal case and for activity coefficient independent of composition over the relevant composition range. ere, c is the concentration and D the diffusivity of the mobile component. The experimental technique that we have used to measure Z* for the isotopes of hydrogen individually dissolved in each of two transition metals has been developed from a method used by Wagner and Heller.4 (A somewhat similar method was also used by Herold.5) A wire or thin rod of the metal under study connects two volumes of gaseous hydrogen at identical pressures; hence grad um = 0. A direct current is made to pass through the specimen, serving to maintain the specimen at the desired temperature and also to produce the electromigration of the hydrogen dissolved in the metal in equilibrium with the gaseous hydrogen. Under these conditions, the flux of hydrogen from one volume to the other is given, from Eq. [I] for grad( um/T) =0by

Jan 1, 1968

By T. M. Morris

THE rate of flotation of solid particles determines the percentage recovery of these particles which can be obtained during a given time interval. It is an established fact that the recovery is greatest in the fine sand size range and falls off on either side of this size range. It is also a fact that the history of the development of concentrating devices has been marked by a desire to recover the small particles: tables were developed to treat material too fine to recover in jigs; flotation recovers material too fine to be recovered on tables. As our ores become more complex and require finer grinding, a greater proportion is in the slow-floating size range. It is therefore of economic importance that the effect of size of particle upon rate of flotation be studied. Many studies have been made along this line. The present investigation attempts to quantify the rate of flotation by means of a rate equation, and then compares the effect of size upon the rate of flotation. It was found that the flotation rate constant increases with increase in diameter of particle in the size range smaller than the optimum size particle. The flotation rate constant decreases with an increase in diameter of particle in the size range coarser than the optimum size particle. This suggested two different actions taking place, and these are discussed. Suggestions for further work in order to improve the flotation rate of both fine and coarse particles are made. The usual method of expressing rate is to plot cumulative percent recovery vs time. If we knew the equation of this kind of curve we could replot it as a straight line, and the slope of the line would be an index of the magnitude of the flotation rate. It is easier to compare straight lines than curves. The basis used for obtaining the equation of the recovery vs time curve is the law of mass action. This law states that the "rate of a chemical reaction is proportional to the `active masses&apos; of the reacting substances present at any given time." This, of course, implies a constant temperature. We can modify this for our use by using the term flotation reaction instead of chemical reaction and the term floatable particle instead of active masses. [ ] where C denotes concentration of particles, t denotes time, k denotes a proportionality constant. If the exponent of C is 1, then we have a first order rate reaction. If the exponent of C is 2, then we have a second order rate reaction. For a first order rate reaction, we obtain, after integration, [ ] where k is again a proportionality constant and has the dimension of the reciprocal of time. C, is the original concentration or weight or percentage of floatable particles. C, is the concentration or weight or percentage of floatable particles remaining in the flotation cell after time t. If all particles of the mineral to be floated were capable of floating we could take C, as 100 and C, would be 100 - R, where R is the cumulative percentage recovery of mineral at time t. But it is not usual for all of the particles to be capable of floating, because of surface oxidation, etc. Therefore, we must introduce a factor x which is the percentage of unfloatable mineral. Hence the first order equation is [ ] It has been proposed by various workers1-3 that this equation describes the flotation rate. More recently N. Arbiter4 states that a second order rate equation fits the recovery vs time curve more closely than does a first order rate equation. Morris&apos; has discussed the evidence presented for this statement. It has been concluded that the first

Jan 1, 1952

By F. A. Crossley

The additions: o, Sn, Zr, Cb, Mo, and V were studied for their effects on the a/a + Ti3A1 boundary of Ti-A1 base ternary alloys. These additions were chosen because of their importance to commercial titanium alloy practice—oxygen as the major impurity (in terms of influence on mechanical properties) and the others as major alloying additions. The composition and temperature ranges of investigation varied according to the system as shown in Table I. The principal means of investigation was light-microscopy. The basis of the ternary studies was the recently determined titanium-rich end of the Ti-A1 system.&apos; MATERIALS, METHODS, AND PROCEDURES Ingots were prepared in 15 g size for all alloys except those of the Ti-Al-Mo and Ti-A1-V systems which were prepared in 20 g size. These alloys were prepared from high-purity, electrolytically refined titanium obtained from the Bureau of Mines, Boulder City Metallurgical Laboratory, Boulder City, Col., and Chicago Development Corp., Riverdale, Md., for the 15 g and 20 g ingots, respectively. The alloying additions were obtained from commercial sources, and were at least of 99.9 pct purity, except the V-15 wt pct A1 master alloy for vanadium additions. This alloy was of 98.2 pct purity; the major impurities were 0.37 wt pct Fe and 0.38 wt pct Si. The ingots were prepared by multiple melting in a nonconsum-able-electrode arc furnace. The ingots were covered with Markal coating "CR-T22" (Markal Co., Chicago) to protect them from scaling. Markal coating is applied as a slurry of solids in a volatile carrier liquid. The coated article is air dried. Upon heating to the hot working temperature the coating fuses to form a glassy, protective film. The ingots were heated to 1000°C and rolled to 0.16 in. thickness, reheating after each pass. The glassy film was removed by sand blasting. Ten mils were removed from all surfaces by grinding and/or pickling (3 pct HF, 30 pct HN03, balance water). Grinding was always followed by pickling to remove traces of the grindmg medium. Hydrogen removal was accomplished by vacuum annealing at 1000°C for 2 hr to a final pressure of about 0.02 µ Hg. This was followed by annealing in evacuated Vycor bulbs (800°C, 2 hr, ice brine quenched (IBQ)) in order to maximize ductility. The materials were then lightly pickled and cold rolled to 0.12 in. thickness or cracking, whichever occurred first. After rolling, 1/2 by 1/4 in. specimens were cut for the equilibration anneals given in Table 11 and carried out as previously described.1 Final polishing of the specimens for metallographic examination was done by electrolytic means. Specimens were first examined without etching under bright field and polarized light illumination, for this is the only means of detecting the "two-phase" phenomenon.1,2 The term "two-phase syndrome" refers to Ti-A1 al-loys which appear on the bases of their chemical, phys-ical, and mechanical properties, to be two-phase, but are actually single phase and inhomogeneous in composition. Since processing and heat treatment of the alloys of the first group were completed before the two-phase syndrome was discovered, a number of the specimens were found to exhibit this phenomenon—80 pct of those of the Ti-Al-Zr system, 5 pct of those of the Ti-Al-Sn system, 30 pct of those of the Ti-Al-Zr system. The affected specimens were homogenized by heating above the ß transus temperature and quenching. The heat treatment and working schedules to accomplish this are given in Table 111. After rolling, specimens were pickled (3 pctHF, 30 pct HNO3 in water) to remove 1 to 2 mils from the

Jan 1, 1970

By M. I. Sherman, J. D. H. Strickland

USE of a hydrometallurgical approach to the oxidation of sulfide ores and extraction of metals therefrom may have advantages over the more common smelting techniques when a low grade deposit is difficult to concentrate or the subsequent separation of metals, coexisting in the ore, is laborious by any known smelting operation. For economic reasons, the most promising oxidants are either atmospheric oxygen or electric power. The use of oxygen, or air under pressure, has recently been revised. Pyrrhotite has been converted to iron oxide and elementary sulfur&apos; and a variety of sulfides have been treated by Forward and co-workers.2-4 Generally sulfate is the end form of the sulfur but with galena in an acid medium, elementary sulfur can be formed." For economic reasons chlorine and ferric iron salts are about the only possible alternatives to the atmosphere as oxidizing agents for base metal sulfides. If aqueous solutions of chlorine or ferric iron are employed, the reduction products can be oxidized electrolytically in situ and used again, thus acting as catalysts for electric power as oxidant. The use of ferric salts for this purpose is established hydrometallurgical practicea but, although chlorine gas has been employed in the dry state at an elevated temperature, its use in aqueous solution at or near room temperature has not found favor. The reaction of chlorine water with the soluble sulfide ion has been studied by several workers,7-9 and both sulfate and elemental sulfur are found as end products, the latter being favored by the presence of a low concentration of oxidant relative to that of sulfide in solutions of about pH 9 to 10. Of direct bearing on the work in hand are an early American patent" and a recent Austrian patent." The former advocates stirring powdered ore with an aqueous solution of ferric chloride chlorine oxides and chlorine. In the latter it is claimed that both metal and sulfur can be obtained by electrolysis, in a diaphragm cell, of a metal ore slurry in brine. Details in these patents are scant and no data or explanation is given for the mechanism of the reaction which, in the Austrian work, is attributed to the (unlikely) action of nascent chlorine at the anode surface. No mention is made of possible differences in behaviour between various ores. Apparatus A complication encountered when working with chlorine water is that a serious loss of chlorine occurs by gas partitioning unless an enclosed system is used and any air space in the apparatus is kept very small and constant. Arrangements were made, therefore, to take out samples for analysis without letting air into the system to replace the liquid removed. For convenience in studying a heterogeneous reaction the apparatus was so designed that a reproducible controlled stirring rate could be maintained and the ratio of surface area of ore to volume of solution was approximately constant throughout any experiment. The apparatus used is shown in Fig. 1. The ground ore was placed in the horizontal cylindrical vessel, A, of about 1 liter capacity, heated by a constant temperature circulating bath pumping water through the concentric jacket, B. By adding chro-mate to this water, an ultraviolet radiation filter effectively surrounded the reaction vessel, greatly reducing any possible photochemical decomposition of chlorine solutions. Stirring was effected by glass paddles, C, attached by an axle to a magnet which was rotated by another powerful Alnico magnet, D, outside the glass end, this magnet being itself rotated by an electric motor electronically controlled to constant speed. Speed could be varied from about 150 to 900 rpm and was measured and held to within 1 pct of a given value. The end of the reaction vessel remote from the stirring magnet was closed by another one-ended glass cylinder, E, connected by thin polyethylene bellows, F, clamped by screw clamps and watertight rubber gaskets to the main vessel. Through E, a glass electrode and calomel electrode projected into the solution and a hypodermic syringe pierced a small bung and allowed acid or alkaline to be added to maintain a constant pH. By pushing the fully extended bellows until the two cylinders touched, from 50 to 100 ml of solution could be forced out through a sintered disk into the three-way tap system, G, either to waste (for flushing purposes) or up into a 10 ml burette where the solution could subsequently be measured out for analysis. The ore samples were introduced at H, the tube being stoppered by a thermometer of —1 to +52ºC range, graduated to 0.1°C intervals. To prevent ore from being ground in the end bearings of the stirrer these bearings were pro-

Jan 1, 1958

By G. A. Vissac

The only fine coal washer with proved automatic controls, the feldspar jig is capable of good efficiencies even at low separating gravities, handles a variety of products, and treats 150 tph and over. IN continental Europe the feldspar jig is used almost exclusively for cleaning the fine sizes of coal; it operates with an artificial bed, made up generally of pieces of feldspar or of any other hard and heavy rock with good cleavages. A primitive form of this machine requiring close supervision was used in this country years ago, but output was small. The modern machines are generally air-pulsated Baum-type jigs, with capacities up to 150 tph, and treat sizes from % in. to 0, usually previously dedusted or deslimed. These jigs are equipped with very accurate and sensitive automatic controls insuring satisfactory operation even at low separating gravity and with feeds irregular in quality and quantity. This paper will deal more particularly with coal cleaning separation, but the technical studies apply equally to all minerals. Theory of the Feldspar Jig To understand fully the operation of the feldspar jig and to appreciate its potential value, it is necessary to measure and analyze the motion of small particles of various specific gravities, falling in various media, under various conditions. As no practical formulas were available for that purpose, the writer has developed new theories and established new sets of formulas, which cannot be demonstrated here. They are applicable to all minerals and to many problems of coal or mineral concentration. These formulas do not pretend to absolute accuracy, but results, tested by comparison with experimentally recorded data, are sufficient for practical purposes, as they give definite indications of trends, relative values, and order of magnitude of the many factors involved. For pulsating motions no earlier formulas are available. In the case of continuous currents or motions, such formulas as Rittinger&apos;s, Allen&apos;s, or Stokes&apos;, over a hundred years old, apply only to special shapes and sizes of particles, involve factors and coefficients difficult to measure or appreciate, and deal only with free motions. They are of little use in solving practical problems. Units used with the formulas presented here are in the CGS system. Lateral friction and suction have been taken into account according- to methods currently used in aerodynamics, and only hindered motion is dealt with. As the feldspar jig is primarily intended to create a fluid bed condition, the mixture of fluids and solids obtained is homogeneous, and the apparent specific gravity of the separating medium is calculated accordingly. For instance, if 20 pct of the volume is coal and shale, with an average of 1.60 sp gr, in a liquid of 1.10 sp gr, the actual specific gravity of the separating fluid is 0.80 x 1.1 + 0.20 X 1.6 = 1.20. The fundamental equations are as follows: The general motion of a particle falling in a medium of specific gravity equal to u, hindered motion. is dv/dt = g/Ls [ L (s-u) - u/g v2 [1] g = 981 cm per sec, acceleration of gravity, and L = thickness of the particle of specific gravity (s) and velocity (v). The initial acceleration dv/dt = g (1-u/s ) [2] is a function of the specific gravity of the particle, only for a given medium, and independent of its dimensions—an ideal separating condition. The terminal velocity Vt = gxL- (s-u)/u, [3] for a given value of u, is a function of s and L. Two particles, L, s, and L2 s2, are said to be equivalent if they have the same terminal velocity, and accordingly L1/L2=s2-u/s1-u. [4] Two such particles cannot be separated by continuous currents, in any concentrating device. Because the initial accelerated motion, which provides for efficient separation, is followed by a constant velocity, which has a limiting effect, it is essen-

Jan 1, 1956

By N. K. Chen, R. Maddin

THE textures of straight-rolled and of cross-rolled molybdenum were first determined with the aid of pole figures by Custers and Riemersma.&apos; These authors have shown that for straight-rolling, the main texture was (100) [0111 with a considerable spread about the rolling direction. After cross-rolling a second texture was obtained in which there was a [111] axis perpendicular to the rolling plane, possessing a rotary symmetry. Recently Semchy-shen and Timmons2 in their study of preferred orientation of arc-cast molybdenum sheet obtained similar pole figures. In these two investigations, polycrystalline materials were used. In the main, the textures of molybdenum in these cases are qualitatively consistent with rolling textures of other body-centered cubic metals, such as iron and Fe-Si alloys." In the present investigation, single crystals of molybdenum were deformed by rolling with respect to specific crystallographic planes and directions. Since the deformation textures of polycrystalline aggregates have been related intimately to the behavior of individual grains,4 a study of possible correlations of final textures with respect to the initial orientations of the single crystals might conceivably lead to a better understanding of the textures. Annealing treatments were carried out after deformation in order to study the recrystallization characteristics as well as the recrystallization texture. Rolling of Single Crystals Single crystals of molybdenum (about 1/8 in. in diarn x 1-in. long), grown by the method previously described,5 were cold-rolled without intermediate anneals. Except for specimens MR-1 and MR-2, which were rolled at random in the preliminary test in order to find a proper rate of reduction, all other specimens were carefully documented as to their respective orientation before deformation by means of X-ray Laue back-reflection methods. A stereo-graphic projection was constructed from which it was possible to determine a particular plane and direction to be considered for rolling. Parallel flat surfaces were then polished metallographically with respect to a reference scratch on the specimen which was mounted in sealing wax. These flat surfaces contained the plane chosen for rolling. After etching, a Laue back-reflection photogram was again made of one of the flat surfaces to determine the exact plane of rolling. The initial orientations of all the specimens (specified by two elements for each crystal, direction of rolling and the pole of the rolling plane) are summarized in Fig. 1. The specimens were mounted in plasticene between two hardened Si-Fe plates. The sandwich was then rolled down, keeping the direction constant in the case of straight-rolling. In cross-rolling (MR-10, MR-11, and MR-12) the sandwich was rotated 90" after each pass so that every first and third pass contained the same rolling direction. Specimens MR-14, MR-15, and MR-16 were compression-rolled following the manner of Barrett." In these cases the direction of the sandwich through the rolls was changed by 3" to 5" for each pass until the specimens were rolled to the desired reduction in thickness. It was found that if extreme care was exercised in rolling, i. e., the amount of deformation per pass was extremely small, the specimens could be rolled to a large reduction in thickness. The rate of reduction used, with a single exception of MR-1. was generally 0.001 in. per 10 passes. Thus, it took about 800 passes to reduce a specimen to a final reduction in thickness of 87 to 98 pct. The results of rolling are shown in Table I. Cold-Rolling Textures The final orientations were determined by the conventional Laue transmission method," using molybdenum radiation, with or without a zirconium filter. Pole figures were plotted from (1101 and (200) reflections in which three degrees of intensity— heavy, medium, and light—were determined visually. Three main types of textures have been observed from the deformed single crystals. These are: 1—a

Jan 1, 1954

By W. K. Lewis, Lombard Squires, W. I. Thompson

The authors presented an article2† last year on colloidal properties of clay suspensions in which they attempted to sustain the position that the behavior of clay suspensions is due primarily to the mechanical interference of the platy particles, the nature and extent of the interference being profoundly influenced by the character of the surfaces of the particles, which in turn is determined primarily by the nature and amount of adsorbed foreign materials held on the surface of the particles by forces which are predominantly chemical in type. The following discussion is a continuation of that article to extend these same interpretative points of view to the behavior of clay gels. Insight into the mechanism of gelation is certainly of outstanding importance in the handling of drilling muds. In the former article it was suggested that the thin, flat plates that constitute the ultimate clay particles may build up aggregates by the overlapping of the ultimate plates face to face much longer and perhaps also much wider than the ultimate plates themselves, but not appreciably thicker. Exhaustive microscopic examinations of characteristic clays show no tendency for the larger particles, clearly visible under the microscope, to orient themselves in this way. It is true that the gelation of the clays is due primarily to the smallest particles, unresolvable other than by the ultramicroscope, so that the possibility of the deve1opment by them of an overlapping structure is not excluded. Furthermore, as one approaches the limit of resolving power of the microscope, the difficulty of observing accurately the shapes and relative positions of particles incresses excessively. However, in the absence of any observable tendency toward overlapping orientation of the large, visible particles, one hesitates to ascribe such a tendency to the smaller particles beyond the range of visibility. Should it develop that one must exclude the assumption of overlapping orientation, the explanations offered in the previous article are changed in only one respect; namely, one would now have to assume that the ultimate particles themselves have length, and probably also width, very large in comparison with their thickness.

Jan 1, 1936

By Lombard Squires, W. K. Lewis, W. I. Thompson

The authors presented an article2† last year on colloidal properties of clay suspensions in which they attempted to sustain the position that the behavior of clay suspensions is due primarily to the mechanical interference of the platy particles, the nature and extent of the interference being profoundly influenced by the character of the surfaces of the particles, which in turn is determined primarily by the nature and amount of adsorbed foreign materials held on the surface of the particles by forces which are predominantly chemical in type. The following discussion is a continuation of that article to extend these same interpretative points of view to the behavior of clay gels. Insight into the mechanism of gelation is certainly of outstanding importance in the handling of drilling muds. In the former article it was suggested that the thin, flat plates that constitute the ultimate clay particles may build up aggregates by the overlapping of the ultimate plates face to face much longer and perhaps also much wider than the ultimate plates themselves, but not appreciably thicker. Exhaustive microscopic examinations of characteristic clays show no tendency for the larger particles, clearly visible under the microscope, to orient themselves in this way. It is true that the gelation of the clays is due primarily to the smallest particles, unresolvable other than by the ultramicroscope, so that the possibility of the deve1opment by them of an overlapping structure is not excluded. Furthermore, as one approaches the limit of resolving power of the microscope, the difficulty of observing accurately the shapes and relative positions of particles incresses excessively. However, in the absence of any observable tendency toward overlapping orientation of the large, visible particles, one hesitates to ascribe such a tendency to the smaller particles beyond the range of visibility. Should it develop that one must exclude the assumption of overlapping orientation, the explanations offered in the previous article are changed in only one respect; namely, one would now have to assume that the ultimate particles themselves have length, and probably also width, very large in comparison with their thickness.

Jan 1, 1936

To assist the taxpayer of the oil and gas industry in correctly and expeditiously preparing his Federal tax returns, the Bureau of Internal Revenue has prepared a "Manual for the Oil and Gas Industry Under the Revenue Act of 1918." Although the endeavor has been made to anticipate all questions that may be asked, it is recognized that such a manual is only general and cannot cover all cases that may exist. The Manual is based largely upon information gathered during the fall of the year 1918 by a corps of geologists, technologists, and engineers. The investigation was undertaken primarily to furnish a basis for arriving at valuations, and depletion and depreciation deductions in connection with oil and gas properties. All fields in the United States were canvassed. Records of production of thousands of properties were collected and tabulated. These were carefully classified and studied by the most competent and experienced men in the country and the average future production curves and tables of valuation data were produced as a result of this study. Be American! Work and Save. Buy W. S. S.

Jan 7, 1919

By S. Skowronski, K. W. McComas

Page Purpose of investigation.....................&apos;. 354 Details of experiments........................ 357 Experiment Series No. 1, melting copper containing chlorine under carbon dioxide............................... 358 Experiment Series No. 2, melting hydro-electric cathode copper drillings under air................................ 362 Experiment Series No. 3, melting hydro-electric cathode copper drillings under furnace gases............................ 363 Summary.............................. 364 Purpose of Investigation Since cuprous chloride melts at 418&apos; C., boils at 954&apos; C. to 1032&apos; C.,&apos; and is known to be volatile at a much lower temperature, the presence of chlorine in any form in or on copper to be melted has always been looked upon by copper refiners as a possible source of serious copper loss. Although this fact has been known for some time, the copper literature contains little or no information regarding it and the field seems never to have been properly investigated from a metallurgical standpoint. According to Greenawalt,2 cupric chloride, CuCl2, when ignited gives cuprous chloride; therefore cuprous chloride is always formed when copper enters into reaction with chlorine at a high temperature. Cuprous chloride melts somewhat below a dull red heat, and does not volatilize in closed vessels, even if strongly heated, but if heated in the air it goes off as a white vapor, Hofman3 gives the melting point of cuprous chloride

Jan 1, 1919