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By Vladimir Lobanov, Pritchinm Alexander, Nikifor Ageev

"Sulfuric anhydride is one of the most voluminous technological emissions. The possibility of high-temperature SO2 oxidations without catalyst in presence of calcium-bearing filling materials (CaO, Ca(OH)2 and CaCO3) with obtaining of binding material on the basis of waterless calcium sulfate is studied. Due to application package HSC-4 the thermodynamic analysis of the specified interactions is made and following conclusions are drawn: 1) Reactions are feasible in the all range of investigated temperatures (400 – 1000 °?); 2) The best results should be expected at use of ???; 3) The heat of reaction does possible autogenous behavior of process. The researches have shown: 1) Practical possibility of the process; 2) SO2 oxidation without the catalyst is feasible in presence of ???, Ca(OH)2 and CaCO3; 3) The optimum temperature range is 600-800 °?; 4) The content of waterless calcium sulfate in a product reaches 48% that makes it possible to use as the binding material; 5) At excess of ??? the degree of SO2 collection is nearer to 100%. Introduction At processing of sulfide raw materials in metallurgical furnaces the significant amount of sulfur, mainly in the form of sulfuric anhydride is escaped. Rich gases (SO2>3 %) are used for the sulfuric acid or element sulfur production. Chemism of sulfuric acid manufacturing is based on catalytic high-temperature oxidation of anhydride. Poor gases of metal works (SO2 =2,5 %) and power combustion units (SO2 =0,5 %) after clearing discharge into the atmosphere. Commonly, to recovery of weak sulfuric anhydride the chemical and physicochemical methods are applied. A few chemical ways of recycling sulfur dioxide are applied practically. In a number of methods for SO2 recovery a pulp of metals oxides (magnesium, zinc, etc.) with formation of sulfites is used. In other case sulfuric anhydride is catch by weak sulfuric acid in the presence of an oxidizer (pyrolusite ore). Methods of absorption SO2 by solid sorbents, (carbon fibers, silica gels, zeolites) are known and put into practice. Regeneration of the saturated sorbents is realized by thermal decomposition or extraction. Obtained as a result high-concentrated solutions are a commercial product."

Jan 1, 2008

By Samuel L. Hoyt

This paper gives a brief description of an investigation made several years ago on the diffusion of zinc into copper. The material for that study was furnished in the form of thin copper strips coated with zinc. The result was required rather quickly and at not too great an expense, and especially information was desired as to the rate at which zinc would diffuse from the zinc coating into the copper and the temperature at which the operation should be carried out. A study of the requirements of this problem indicated that the solution might be secured by means of six determinations. This is the smallest number that will give the information desired and, at the same time, furnish checks on the accuracy of the determinations which justify an abbreviated experimental program. This does not count a preliminary test which was designed to give some idea of the correct temperature to use. The minimum number of temperatures that can be used is two. Knowing the rates of diffusion of zinc into copper at two properly chosen temperatures, it is possible to calculate the rate for any other temperature, and also to check the accuracy of the determination by means of the heat of diffusion, which is calculated from the effect of temperature on the rate of diffusion. The minimum number of determinations at any one temperature is three. The amount of diffusion which occurs at a fixed temperature is definitely related to the time of diffusion, so that by determining the amount of diffusion for three different time intervals, this relationship may be established and possibly a check on the accuracy may be secured. This accounts for the six determinations or experiments, and suggests the logical plan of the work. The check used here is not generally applicable to diffusion phenomena, but it seems to hold closely enough for the limited amount of diffusion in this investigation to justify its use. The samples used were 5 to 6 mils thick and about 1 in. square. They were placed between iron blocks and set in the hot zone of a nichrome furnace which had been brought to the desired temperature Time was taken from the moment the samples reached the furnace

Jan 1, 1929

By C. W. Washburne

Continued discussion of the paper Of ROSWELL H. JOHNSON, presented at the New York meeting, February, 1015, and printed in Bulletin No. 98, February; 1915, pp. 221 to 226. See also Bulletin No. 101, May, 1915, pp. 1157 to 1162, and No. 103, July, 1915, pp. 1449 to 1450. C. W. WASHBURNE, New York, N. Y. (communication to the Secretary*).-Mr. Johnson recognizes that connate waters must be driven, outward toward the earth's surface. He considers the ascent due to the settling and packing of the underlying sediments and to the formation of gas within the rocks, supplemented by abyssal pressures. The origin of the methane in the sedimentary strata probably is not simple. There are three possible modes of origin: (1) as marsh gas formed near the surface and entrapped in the sediments; (2) from abyssal sources; (3) by the decomposition of organic matter buried in the sediments. The abyssal source is generally negligible, and in all cases doubtful. The third origin is the most important in the gas fields. A fourth mode of origin, by the dissociation of liquid hydrocarbons, frequently has been suggested, but it is improbable, because crude oils are exothermic. Therefore they have no tendency, to split or decompose at low temperatures, as do endothermic substances, such as coal, which is geologically by the loss of methane, water, and carbon dioxide. This cannot happen to a hydrocarbon until its temperature of dissociation (" cracking point") is reached, which is over 250'.C. for the most easily cracked hydrocarbons and over 400° C. for others. Engler says that the dissociation of fats and waxes into oils is an endothermic process, thereby unconsciously nullifying his own theory of the dissociation of these substances at low temperatures. However, recently I have found reason to think that heat is liberated by the disruption of the molecules of fats and waxes, as it is in the molecular decomposition of the substances of wood, coal, etc. If this tentative opinion is correct, and Engler wrong, then it seems that the Engler-Höfer hypothesis of the origin of oil becomes not only possible, but even probable.

Jan 9, 1915

By Richard Moldenke

So FAR as the quality of the product is concerned, the history of the production of pig iron for foundry purposes is one of constant retrogression. The steps in this deterioration began with cold-blast charcoal pig iron, then anthracite iron, coke iron; then gradually warm to hot-blast coke iron, with the charcoal furnaces also heating their blast to get greater tonnages, and finally the present day hot-blast coke irons with scrap additions to the ordinary burden that, according to one European report, have gone as high as 135 per cent. Parallel with this quality retrogression is the enormous increase in furnace tonnages from about 15 tons daily to over 1000 tons per day in exceptional instances of modern practice. The key to this situation is economic pressure. The effect is a growing differentiation between furnace production for gray iron and malleable foundries and for the production of commercial steel. As the foundry is often compelled to draw upon the pig irons made for steel purposes, for economic reasons, whereas the steel industry does not draw upon foundry pig irons proper, the situation is resolving itself into one of grave consequence for the life of the gray-iron castings industry, and hence the intensive present-day feeling in foundry circles for rigid specifications to govern the quality of pig irons sold for foundry use. In the discussion of a paper on the use of scrap in the blast furnace held recently in the Institute, a very pertinent remark was made by one of the participating furnacemen, who confessed that "the things found wrong by the foundryman with his iron were beyond his depth." It may be added that those things are also beyond the depth of most foundrymen who, however, know from their results that they are getting poorer castings today with many pig irons than they did with those same brands in former years. Under the former fracture buying, the foundryman at least could select the strongest metal, as judged by the sledge, from various brands of similar fracture and pig section, and his results proved the soundness of his conclusions. With the advent of iron analysis, and in spite of the growing uniformity of the metal through greater tonnage

Jan 2, 1927

By E. Keller

Some years ago the writer's attention was called to the fact that rolling-mill scales from auriferous copper do not have the gold content proportional to the gold contained in the copper from which they are derived.' So, later, he made a few simple experiments, which are described herewith. In order to test the gold movement on the changing surface of a copper plate under the influence of oxidation, plates 6 in. by 8 in. by 1 in. (15.2 cm. by 20.3 cm. by 2.5 cm.) of converter copper, refined, of 99.29 per cent. purity, and leaded copper with a content of 95.65 per cent, copper, were obtained. Ten cuts were made through the thickness of the plates along the longitudinal center and the silver and gold content ascertained in each of the 10 samples in both plates, as shown in the accompanying illustration. The assay results, recorded in Tables 1 and 2, show that the gold distribution is relatively uniform in both plates, while silver has greater variations, especially in the leaded plate. The plates subjected to oxidation were placed in a red-hot muffle for about 2 hr., two small scarifiers being used as supports. Arranged alongside each other, they nearly filled the width of the muffle, and so were practically under equal conditions of heat and draft. The accurate observance of the time was not possible, however, because of other work, but the time of the exposure of each plate in a pair was identical. At the end of each period, each plate was plunged into water and completely freed of scale, which was carefully collected, dried, weighed, and analyzed. Samples of the plates had also been taken of the molten metal and duly analyzed. Table 3 contains the analytical data for the two plates and their several sheets, or layers, of oxide scales. These figures show that in the oxidations of the converter copper the silver is fairly uniform, while the gold is highly irregular and especially low in the first layer. In the oxidations of the leaded copper plate, the silver and gold contents are variable; however, this irregularity is due to two different causes. The

Jan 1, 1919

By Emil Gathmann

STEEL as it is poured, or teemed, into the mold for forming the ingot may be broadly separated into two divisions; i.e., effervescing or gassy steel, also termed evolution steel, and non-effervescing or killed steel, also termed solution steel. Between these primary divisions there are various types having the characteristics of both divisions but really not belonging to either; such steels are termed semi-piping, rising, or wild, as the type may be. True unkilled, or effervescing, steel should contain large volumes of gases, which are evolved while the metal is being teemed, or cast from the ladle nozzle into the mold, and while the temperature of the steel is being reduced prior to the solidification or freezing of the steel, the upper portion, or top, of the ingot remaining liquid due to the evolution of gases until an ingot skin of considerable thickness has been formed. These gases consist principally of hydrogen, carbon monoxide, nitrogen, and ammonia. It is generally understood that nitrogen gases are the first evolved and form the skin blowholes, at times troublesome, in the forming solidifying ingot. Ingots made of effervescing steel will always contain a large number of blowholes. Such blowholes are not deemed objectionable in various products if they occur well within the interior of the ingot where they will not be subject to oxidation upon the ingot's cooling and subsequent re-heating and rolling or forging. Very little top or bottom discard is taken from this type of ingot as pipes, or large shrinkage cavities, at the upper portion of the ingot do not usually occur, the difference in volume between the liquid and the solid steel (6 to 10 per cent.) being compensated for by the innumerable blowholes distributed throughout the body of the , ingot. Of the 40,000,000 tons of steel made in the United States during the year 1919, at least 35,000,000 tons of ingots were made of gassy or semi-gassy steel. Killed, or solution, steel is termed true piping steel from the characteristic pipe or shrinkage cavity that usually occurs in the uppermost central portion of the ingot.

Jan 8, 1920

Dimitri Konstantinovitch Tschernoff, was horn in Petrograd, Russia, on Nov. 1, 1839, and died in Yalta (Crimea) in the south of Russia, on Jan. 2, 1921. He obtained his early education in the Russian Gymnasium, corresponding to the American high school, and in the Technologic Institute. On graduation from this Institute in 1858, he was engaged as a professor of geometry and algebra and later became a librarian and superintendent of the museum in the same Institute. He also attended lectures in the mathematical physics section at the Univrrsity of Petrograd from 1859 to 1862. In 1866, Professor Tschernoff left the Technologic Institute and entered the employ of the Obouchoff steel plant, founded in 1863 for the manufacture of guns. Here he did his most important work on the heat treatment of steel, its crystallization and metallography. In 1880, he left the Obouchoff plant and went to the south of European Russia, where he discovered and developed some rock-salt mines. This enterprise brought him a rather large fortune. In 1884, he returned to Petrograd and during the next four years held several prominent positions in government departments. In 1899, he became professor of metallurgy in the Michael Artillery Academy, and retained that position until the time of the Russian Revolution. In 1902, Professor Tschernoff was elected an honorary member of the American Institute of Mining and Metallurgical Engineers. In September, 1917, Professor Tschernoff was sponding his vacation, as usual, in the city of Yalta (Crimea) in the south of Russia, with his wife and one of his daughters. The revolution progressed so rapidly that they were unable to return to Petrograd, and were compelled to stay in Yalta without provision for the winter season. Suffering from hunger. and lack of sufficient clothing, and deprived of his books, Tschernoff nevertheless continued his studies and gave a number of lectures on steel at the Polytechnic Institute. At the same time he worked hard on some. mathematical problems. His health broke down through long-continued under-nourishment. His works in the metallurgical field are well known to the students of metallurgy; good abstracts of his most important papers were published in Revue de Metallurgie (1915, pp. 829-882) in commemoration of his 75th birthday.

Jan 1, 1922

By Robert W. Hunt

When I had the honor of presenting to the Institute at the Buffalo meeting in October, 1888 (Trans., xvii., 226), my paper on " Steel Rails and Specifications for their Manufacture," I expressed my hesitancy in submitting my ideal rail-sections. Since then, continued residence in Chicago, perhaps, or greater intercourse with railroad officials, has either given me more courage or has taught me that so little is really known on the subject that one is safe in expressing one's views, let them be ever so erroneous. As a further personal excuse, I may remind you that " fools rush in," etc. At all events, I would now call attention to certain rail-sections which I believe to be good. I do not say they are the best, but I feel sure they have more merit than the majority of the adopted heavier-sectioned rails. In determining the proper form for a rail, the subject should be considered from two points; first, and most important, the duty required ; second, and of almost equal importance, the influence of existing details of manufacture upon the character of the finished product. It is perfectly proper that all the strains to which the rail will be subjected should be considered and calculated. But its ability to resist them will depend quite as much upon the character of the metal as upon the form of its section. That which would be the realization of the ideal with good steel would be disappointment with poorer metal. Therefore, the railroad engineer should always have in mind and pay due respect to what the metal worker may give him—the may being the factór of danger to be covered by his factor of safety, and possessing greater importance than any formula laid down by never so eminent authorities. It is well-known how positive is my conviction that high heat during manufacture and good rails cannot go together; hence, if we insist upon the avoidance of this evil by rail-makers, we must give them sections which can be made at low temperatures with commercial as well as technical success. The market-price for rails controls the practice of makers, and,

Jan 1, 1889

By Amer S, Novais A. Q, Limpo Gil J

A proprietary hydrometallurgical ammonium chloride process for the recovery of not only zinc, but also copper, lead and silver from sulphidic zinc-rich concentrates has been developed at bench scale by CENIM and INETI (ex-LNET) as part of a research project supported by the Commission of the European Community (DGXII). This paper deals with the innovative chemical aspects applied to this chloride process and also with the more relevant data relating to mass balance, heat balance and process economics. Under mild temperature and oxygen pressure leaching conditions it is possible to extract practically all the zinc together with the other metals of interest and to precipitate simultaneously the solubilised iron fraction as goethite. The pH is kept close to neutrality in spite of the ammonia released in the leaching of the non-ferrous sulphides. A buffer effect is observed mostly due to the formation of zinc ammines which are very soluble in this medium. The zinc is further extracted by D2EHPA, the acidity being neutralised by the ammonia. Most of the ammonium chloride is naturally regenerated in this step. The zinc is recovered as zinc cathodes in a conventional sulphate electrowinning circuit. All the main raw material consumptions excluding the concentrate, such as oxygen, lime and ammonium chloride are linked to the sulphate formation in the leaching step which must be kept as low as possible by decreasing the reaction time under neutral conditions. The process analysis is complemented by the economic evaluation of a reference case. Difficulties encountered in finding a more convenient method of assessing the economics of the process in the absence of a reference price for a complex sulphide concentrate are examined and discussed. The reason why this analysis was performed with a much more optimistic metal prices scenario is also highlighted. The process economics are primarily dependent on the zinc market quotations and of course on the concentrate cost. Around 70 per cent of the total revenue is due to zinc sales. Assuming an internal rate of return of 17 per cent, the price of the concentrate can be as high as 255 $US/t for a plant capacity of 320 000 t/y (90 000 t/y of zinc).

Jan 1, 1993

By S. B. Flagg

Advancement in the art of burning fuels for steam generation has been so marked and so rapid in the last 10 or 15 years that one may well hesitate to classify as unsuitable for stationary steam boiler firing any material having a fuel value. This statement should not be interpreted to mean that any existing boiler plant can successfully utilize any fuel with which it might be supplied. It does mean, however, that almost without exception it is possible to design and construct stationary boiler plants so that they can be operated with whatever coal is the economic supply therefor. In considering the subject of the use classification of coals, it must be recognized, first, that the suitability or unsuitability of a coal for certain uses or conditions may be largely a matter of opinion and, second, that as advancement in the art of burning fuels continues, fuels that may have been considered unsuitable may later be regarded as entirely suitable. This is well illustrated in the creation of a market for slack bituminous coal and for the finer sizes of anthracite that resulted from the development of mechanical stokers adapted thereto. Coke breeze is another fuel of which large tonnages were formerly wasted, that has now been found suitable for use in properly designed furnaces. Again, results that would have been thought quite impossible a generation ago are being obtained in steam boiler plants today with lignites of high moisture content and with coals of excessive ash content. It must, however, be admitted that oftentimes an existing boiler plant can be successfully operated with only a limited number of the coals that are available as possible supplies. We may briefly consider some of the more important factors that may affect the suitability of coals for such a plant. Insufficient or barely sufficient draft to meet peak steam demands is often a limiting factor, and the permissible frequency of fire-cleaning periods is another. In some cases, the action of the molten coal ash on refractory furnace linings prohibits or makes inadvisable the use of certain coals. Again, clinker conditions in the fuel bed or slag conditions on the boiler-heating surface may be much worse with some coals than with

Jan 1, 1930

By Ernest Kirkendall

The amount of research done in the last fen years on the subject of diffusion in solid metals is significant of the importance of this problem. To review the literature dealing with diffusion is unnecessary here. Deschl in 1912 reviewed the work that had been done on diffusion in solids and gave a bibliography of the literature published before that time. Mehl's paper in 19362 is an excellent review of diffusion in metals and contains a large bibliography. Of importance also for it? review and bibliography is an article by 14. I. Krynitsky.~ While considerable material lias appeared in the literature on diffusion in brass, the amount of information is not great compared to that pertaining to some of the other alloys. Most of the information published is of a qualitative nature; that which is quantitative varies considerably. Thus the quantitative determination of the rates of diffusion of copper and zinc in alpha brass by a new method appeared worth while. In the present investigation the rate of diffusion of zinc in approximately the same composition alpha brass has been determined :it three temperatures. Procedure The method used consisted of plating copper on a beta brass, heating it, to allow diffusion to take place, and measuring the concentration of copper by determining the lattice constant of the alloy. This method is unique in that it uses a beta brass of such a composition that at the tem perature at which diffusion takes place the beta brass is saturated wit11 copper. Thus, while the beta brass supplies thc zinc, no diffusion takes

Jan 1, 1939

By Ernest Kirkendall

The amount of research done in the last fen years on the subject of diffusion in solid metals is significant of the importance of this problem. To review the literature dealing with diffusion is unnecessary here. Deschl in 1912 reviewed the work that had been done on diffusion in solids and gave a bibliography of the literature published before that time. Mehl's paper in 19362 is an excellent review of diffusion in metals and contains a large bibliography. Of importance also for it? review and bibliography is an article by 14. I. Krynitsky.~ While considerable material lias appeared in the literature on diffusion in brass, the amount of information is not great compared to that pertaining to some of the other alloys. Most of the information published is of a qualitative nature; that which is quantitative varies considerably. Thus the quantitative determination of the rates of diffusion of copper and zinc in alpha brass by a new method appeared worth while. In the present investigation the rate of diffusion of zinc in approximately the same composition alpha brass has been determined :it three temperatures. Procedure The method used consisted of plating copper on a beta brass, heating it, to allow diffusion to take place, and measuring the concentration of copper by determining the lattice constant of the alloy. This method is unique in that it uses a beta brass of such a composition that at the tem perature at which diffusion takes place the beta brass is saturated wit11 copper. Thus, while the beta brass supplies thc zinc, no diffusion takes

Jan 1, 1939

By A. R. Troiano, W. J. Barnett

IN recent years the demands of space limitations and increased loads, particularly in the aircraft industry, have accelerated the trend toward utilization of ultra-high strength steels. The increased application of such steels has focused attention on the phenomenon of delayed failure or static fatigue. Parts subjected to a static load, after successfully sustaining the load for an extended period of time, may fail in a brittle manner. Subsequent examination of such failed parts by conventional laboratory tests in many cases reveals no apparent signs of embrittle-ment. That is, the material exhibits good ductility and impact resistance. Furthermore, consideration of the service conditions (environment and temperature) under which this brittle failure occurred eliminates its classification as a stress-corrosion or creep type of failure. Recently this unique time dependent fracture process has been the subject of numerous investigations. The most significant result of these studies was the recognition of hydrogen as the source of embrittlement. While the effect of numerous variables on the occurrence of static fatigue failure has been defined, an adequate explanation of these behaviors is lacking. The occurrence of this phenomenon in steels generally has been limited to strength levels in excess of 180,000 lb per sq in. Although steels at high hardness levels have exhibited delayed failure in the absence of hydrogen introduction after heat treat-ment,'.' this behavior was most prevalent when the material in processing had been subjected to an environment conducive to the absorption of hydrogen. Delayed failures have been produced in high strength steels by the introduction of hydrogen

Jan 1, 1958

By D. W. Smith

The beta solid solution phases of the systems copper-zinc, copper-aluminum, copper-tin and silver-zinc are structurally analogous.' R. F. Mehl and 0. T. Marzke2 have shown that the a phase upon segregating from the 6 phase in the system copper-zinc takes the form of needles lying parallel to a [Ill] direction or some similar direction, such as [556], of the parent solid solution, and that the a phase upon segregating from the ß phase in the system copper-aluminum also takes the form of needles. By analogy they assume that in this case also the segregate needles lie parallel to the [ill] or [556] direction in the ß lattice. The purpose of this investigation is to determine whether the structures resulting from segregation of the a phases from the respective ß phases of the systems copper-tin and silver-zinc are analogous to those obtained by Mehl and Marzke in the systems copper-zinc and copper-aluminum. Segregation of the a Phase from the ß Phase in the Copper-tin System Preparation of the Alloy.—An alloy containing 74.92 per cent (by weight) of copper and the balance tin was chosen for this investigation. This alloy, as can be seen from a portion of the constitutional diagram, Fig. 1, of the system copper-tin by Hamasumi and Nishigori,3 with the proper heat treatment should segregate the « phase out of the a parent, solid solution phase. The alloy was prepared from high purity cathode copper (analyzing 99.98 per cent Cu) and Straits tin (analyzing 99.94

Jan 1, 1933

Gold is actively precipitating at grades up to 80 g/tonne at and near the surface of the Waiotapu geothermal system, located in the Taupo Volcanic Zone of New Zealand. Many characteristics of this active system makes it analogous to the environment deduced for epithermal precious metal mineralisation in the circum Pacific region.The near surface area of the geothermal system is approximately 17 km2, caused to an extent by the upflow of deep, neutral pH fluids being deflected into a lateral flow of several km. This fluid has pervasively altered the rhyolite pyroclastic and ash deposits to an assemblage generally characterised by the term propylitic; major vein mineralisation is not observed. The temperatures at the 1100 m limit of drilling are 300¦C, and decrease to the surface along a boiling point curve.Condensation of steam and H S (subsequently oxidised) at the surface (derived 2from deep boiling) results in the formation of heated acid sulphate waters. These have caused a shallow (50 m) cap of advanced argillic alteration. Mixing of this oxidised condensate with the deep neutral pH fluid appears to be the principle cause of gold deposition from thiosulphide complexes. The major focus of gold mineralisation is in Champagne Pool, a hot spring which fills one of several 900 year old hydrothermal eruption craters.

Jan 1, 1984

Page Foreword. By Edmund M. Wise..................... 3 A.I.M.E. Officers and Dircctors...................... 4 Institute of Metals Division Officers and Committees............ 7 Institute of Metals Division Annual Award Certificate............ 8 Institute of Metals Division Lectures and Lecturers............. 9 Photograph of E. H. Dix, Jr., Institute of Metals Division Lecturer...... 10 PAPERS Acceleration of the Rate of Corrosion by High Constant Stresses. By E. H. Dm, JR. (Institute of Metals Division Lecture, T. P. 1204).......... 11 Variation of Internal Friction with Grain Size. By Clarence Zener and R. H. Randall. (T.P. 1146, with discussion) .............41 Changes in Damping Capacity during Annealing of Alpha Brass. By John T. NoRton. (T.P. 1168, with discussion)................49 An Electron Diffraction Study of Anodic Films. By R. A. HarrinQton and H. R. Nelson. (T.P. 1158).....................62 Determination of Orientations by Etch Pits. By Charles S. Barrett .and L. H. Levenson. (T.P. 1171, with discussion).............76 Process of Precipitation from Solid Solution, I—A Crystallographic Mechanism for the Aluminum-copper Alloys. By Carl H. Samans. (T.P. 1186). . . 85 Age-hardening of Aluminum Alloys, IV — Discussion of the Theory. By WilTJam L. Fink and Dana W. Smith. (T.P. 1083, with discussion). . . 95 Structure of Aluminum after Compression. By Charles S. BaRREtt and L. H. evensonON. (T.P. 1104, with discussion)................112 Recrystallization Texture of Aluminum after Compression. By ChaRlEs S. BarRett. (T.P. 1141, with discussion)................128 Plastic Deformation and Recrystallization of Aluminum Single Crystals. By J. A. Collins and C. H. Mathewson. (T.P. 1145, with discussion) . . . 150 Recovery and Recrystailization in Long-time Annealing of 70-30 Brass. By S. E. Maddigan and A. I. Blank. . (T.P, 1166, with disonssion).....170 Correlation of Deformation and Recrystallization Textures of Rolled 70-30 Brass. By R. M. Brick. (T.P. 1144, with discussion).........193 Tensile Deformation of Critically Oriented Brass Crystals. By H. L. Burghoff. (T.P. 1149).............................214 Recrystallization of Lead. By Paul A. Beck. (T.P. 1101, with discussion). . 222 Simple Method of Thermal Analysis Permitting Quantitative Measurements of Specific and Latent Heats. By Cyril Stanley Smith. (T.P. 1100, with discussion).............................236 Metallographic Study of Internal Oxidation in the Alpha Solid Solutions of Copper. By Frederick N. Rhines. (T.P. 1162, with discussion). . . . 246

Jan 1, 1940

By Shadia J. Ikhmayies

"Nanocrystalline fluorine doped tin oxide (Sn02:F) thin films were produced by the spray pyrolysis technique (SP) on glass substrates at a substrate temperature T, = 450 ° C. The hydrated stannous chloride (SnClz.2H20) was used as a precursor and ammonium fluoride (NH4F) and hydrofluoric acid (HF) were used as the doping compounds. A comparison between the compositional, morphological and optical properties of the films obtained by using the two doping compounds was performed by using scanning electron microscope (SEM) observations, energy dispersive spectroscopy by X-rays (EDAX) and transmittance measurements. It is found that the films prepared by using HF have larger grain size, and higher fluorine content than the films prepared by using ~- In addition these films have higher transmittance and higher direct optical bandgap energy. These results are interesting for the use of Sn02:F as a forecontact in CdS/CdTe solar cells.IntroductionTin dioxide is an n-type, wide bandgap semiconductor (about 3.5 eV) and in the form of thin films, it is a transparent conducting material, characterized by high optical transmission (80- 90%) [l]. Sn02:F is the most widely used transparent-conducting oxide material. The transparent-conducting thin films of this oxide are used as electrodes in a variety of optoelectronic devices, as heat mirror coatings in 'smart windows' for buildings, in automobile and airplane windshields, in incandescent light bulbs, in flat-plate and concentrating solar collectors. Tin oxide and zinc oxide, in thin film configuration are technologically important materials because of their applications in photovoltaic cells [2].Among various dopants for Sn02, fluorine is often preferred, because fluorine doping results in films with high transparency and good conductivity [3]. By exploring the literatures, it was found that different sources of fluorine were used to produce Sn02:F thin fihns, among which are ammonium fluoride (NH4F) and hydrofluoric acid (HF) are the most used. Some researchers used~ [2, 4-7] and others used HF [3, 6-8] for doping Sn02 films. Gordillo et al.[7] used both of NH4F and HF and showed that the resistivity of thin films obtained by using HF was lower than that of similar films obtained by using NH4F by a factor of 2.2. They also found that the films obtained by using HF have more random orientations."

Jan 1, 2013

By R. J. Murphy, N. J. Grant, J. W. Dowding

A large number of blast furnace slag-metal tests were examined to determine if the manganese reduction could be used as a primary indicator of the degree of oxidation or reduction of the slag and of its desulphurizing power. Slag basicity and temperature were also evaluated. Two laboratory heats were made and sampled prior to reaching equilibrium to check blast furnace data. IN a recent investigation of the factors affecting desulphurization in the blast furnace, is was evident that manganese reduction appeared to parallel the course of desulphurization. Grant, Kalling, and Chipman1 pointed this out in a series of time studies utilizing closely controlled laboratory melts. Fig. 1 is a composite plot of sulphur removal and manganese reduction as a function of time under two slags of different basicity. Manganese reduction appears to approach equilibrium at approximately the same rate as does sulphur. It was also demonstrated that the addition of oxygen to the slag, as manganese oxide, caused a sharp reversal of sulphur from the slag to the metal.' It has been shown that "Excess CaO" was a primary factor in measuring the degree of desulphurization under ideal reducing conditions,1,2 the following reaction being representative of the process: CaO (slag) + S + C (solid) = CaS(slag) + CO (gas) It was also evident that a second reaction could drive the sulphur from the slag into the metal. A suggested reaction was' CaS (slag) + 0 = CaO (slag) + S Any change in the oxidizing power of the system would thus affect both the sulphur and the manganese without causing any change in the calculated basicity of the slag. "Excess CaO," "Excess Base," and other similar basicity values, under such oxidizing conditions, would therefore not be the best measure of desulphurizing power; instead, as was shown by and Chipman" he oxygen content of the slag at low oxygen levels would be the controlling factor. Unfortunately, the extent to which FeO is reduced in the blast furnace makes it difficult to utilize slag FeO as an accurate indicator of the degree of oxidation. By comparison, manganese reduction in the blast furnace proceeds more slowly and is generally only about 40 to 70 pct complete. manganese, which is present in significant amounts and is readily analyzed, offers an opportun-

Jan 1, 1954

By Ellen H. Richards

It is of importance to analysts to have a ready means of detecting the presence of small quantities of titaninm in iron ores and in certain fluxes and slags. The method given in Elderhorst's Blowpipe Analysis (fusion with potassium hydrogen sulphate) requires considerable practice, in order so to regulate the heat that the titanium oxide shall become soluble. In Brash's Determinative Mineralogy is found a method which, at least in inexperienced hands, has given better results, i. e., fusion of the substance to be tested with sodium carbonate on charcoal in the reducing flame. The solution in hydrochloric acid of the bead thus obtained, boiled with tin or zinc, gives the characteristic violet color; but when the mineral contains less than four per cent. of titanium oxide, long boiling and consequent concentration is necessary. In fact the test would seem to be much less delicate than is generally supposed. In the course of some analyses I quite accidentally found that a peculiar color is given to turmeric paper by solutions of titanium chloride. This color is hard to describe, being modified by the quantity of ferric chloride present in the solution ; but it is neither the orange of zirconia nor the red of' boron. It is rather a dull shade of purple, arid is easily recognized when the paper is dried, although the color fades in a few hours. By this means a solution containing .015 per cent. of titanium oxide can easily be tested. The same solution, treated with tin, required to be concentrated to one-tenth its bulk before a decided color could be obtained. The color given to turmeric paper is intensified after the solution has been treated with tin. This and some other indications show that the best shade of color is given by the titanons chloride rather than by the titanic chloride, and no other salt of titanium than the chloride has been found to give the color. Another peculiar property of titanium salts has come tinder my observation. When titaniferous minerals are soluble in nitric acid, and the solution is subjected to the action of the battery, the soluble titanium salt is converted into the insoluble oxide and appears on the electrode, in some cases, as a white coating; this

Jan 1, 1883

By L. Arbore

Introduction Mine operators are interested in energy conversation in two ways. With our finite sources of energy, we are concerned for future generations. In addition, as mine operators, we want to minimize energy costs. Moving material represents a substantial amount of the energy used in mining operations. Wheeled vehicles are used extensively to move materials. And they derive all their energy from fuel. Energy is also required to overcome the vehicle's inertia, and internal and external frictional forces. Included in the vehicle's frictional forces is its suspension. Tires are an important part of this suspension. What influence do tires have on the overall fuel consumption of the vehicle? Does tire construction affect this influence? As far back as 1896, it was apparent that tires were a factor in fuel consumption. A test was devised in France using a coal-fueled steam-driven auto. The test measured whether there was any fuel savings with the new pneumatic tires rather than of the then commonly used solid tires. The result was a 28% savings in water and a 29% savings in coal on pneumatic tires. Today, the pneumatic tire is accepted, but there are differences in present constructions. Tire Construction: Bias vs Radial There are basically two types of tire construction, bias and radial. Bias tires have been around for about 60 years. Radial tires are more recent. They were developed to improve a tire's ability to withstand higher speeds and loads, as well as to improve tire life and vehicle handling. Another advantage of the radial tire is its lower rolling resistance. This characteristic results in lower fuel use by a vehicle. This has been demonstrated with passenger cars and over-the-road trucks. It is now being demonstrated with earthmoving equipment. A basic description of both types of tire construction should now be reviewed: The casing of a bias-ply tire is made up of crisscrossed textile plies or layers. The cords of these plies run on a bias, from bead to bead. The cords of each ply run on an angle relative to the cords of the adjacent plies. As the tire rolls and deflects, the angle between the cords changes, like the blades on scissors (Fig. 1). The cords of one ply pull one way, and the adjacent ply pulls another, straining each other. This movement generates heat. Since the same layers of cords wrap around under the tread, they

Jan 9, 1984