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By C. H. Aldrich

For many years the City of Prescot, about 8 miles northeast of Liverpool, has been the home of British Insulated Cables, Ltd., one of the largest wire mills and manufacturers of electrical equipment in England. Since this location is close to the industrial center of the country and the seaboard, with good railroad transportation facilities, it was a logical site for the new refinery. Early in April, 1932, the writer was called upon to prepare a preliminary layout and estimate of cost of the proposed plant, and shortly afterward, following a discussion of these figures with officials of British Insulated Cables, in England, the decision was reached to proceed immediately with construction of the plant. The refinery was built by British Insulated Cables, Ltd. Designing of the plant was started early in May, 1932, orders for equipment being placed as rapidly as possible. On July 18 the first steel was erected and the first charge was cast on Jan. 5, 1933. No difficulties of any consequence were experienced in starting the plant and the grade of copper produced was quite satisfactory after the first charge. The initial capacity desired was 2500 tons of refined copper per month. Since only one furnace was to be built, it was necessary that it should have sufficient reserve capacity to catch up after unavoidable shutdowns. It was also necessary to lay out the plant so that it would operate efficiently at this tonnage and at the same time permit expansion in the future, if necessary, to several times its original capacity. In order to meet these conditions and also to take full advantage of the space available, the layout shown in Fig. 1 was adopted. The principal plant structures are a blister storage aisle, casting building, wire-bar storage building and a coal-pulverizing building. Additional smaller structures include a brick and charcoal shed, pumphouse, drill room, water-cooling tower, clay-preparation shed, substation and plant office. Incoming blister is received in either broad-gage railway cars or steam motor lorries in the blister storage aisle, unloaded by overhead electric crane to narrow-gage cars, weighed and sampled, then either sent directly to the furnace or placed in storage. After refining, the copper is cast on the wheel, passes through the cooling bosh and is

Jan 1, 1934

By HORACE V. WlNCHELL

Location. THE St. Helens mining-district, indicated in sketch-map, Fig. 1, is chiefly in Townships 9 and 10 North, Ranges 5 and 6 East, of the Willamette meridian, in Skamania county, Wash. There is no railroad or even a wagon-road at present connecting it with any base of supplies; access is usually by wagon-road for FIG. I.-SKETCH-MAP OF THE STATE OF WASHINGTON. about 50 miles from the town of Castle Rock to Spirit lake, and from that point by pony-trail from 6 to 10 miles farther. History. Nearly 20 years ago two German farmers, totally inexperienced in prospecting, penetrated this region upon a hunting and fishing-trip. Their attention was drawn to numerous joints and crevices filled with black, glistening tourmaline, and con-

Oct 1, 1912

By Alexander Field

INTRODUCTION THE Bureau of Mines is investigating the problem of slag viscosity, its variation with the temperature and with the composition of the slag, and its effect upon the distribution of the sulphur between molten iron and slag, as introductory to a series of contributions to the theory of the metallurgical processes. The method of measurement, viscosity, apparatus, furnace and other accessories mentioned in this paper have been described fully in a Bureau of Mines report.1 THE LITERATURE ON SLAG VISCOSITY The viscosity of blast-furnace slag had not been measured previous to the investigation described in this report. A number of investigators have determined the "fusibility," or softening temperature, of slags by means of the cone method or, other deformation method, but these methods supply only limited information regarding the temperature-viscosity relations.-of the slag in question. Any deformation method that may be employed indicates only the temperature at which the slag attains a more or less definite viscosity, the magnitude of the value obtained depending on the method used. For details of the various methods used by different investigators, see, the Bureau of Mines paper already referred to. An isolated measurement by Doelter on a single mixture at 1,300° C. represents the highest temperature reached in the various viscosity investigations previous to those described in this report, in which results have been referred to absolute units. Arbitrary deformation tests have of course been made at much higher temperatures.

Jan 2, 1917

By O?Harra B. M.

THE work here described had for its purpose the procuring of data from which some quantitative estimate might be made of the results obtainable by using oxygen-enriched air in roasting zinc ores on a commercial scale. The principal metallurgical advantages of using enriched air in roasting zinc ores would be: 1. The rate of roasting would be increased, with consequent gain in the capacity of the roasting furnace. 2. As less air would be required for roasting, the volume of hot gases leaving the furnace and the heat carried out of the furnace as sensible heat in these gases would be less per ton of ore roasted; partly for this reason and partly because of the increased quantity of heat generated in the furnace by the larger amount of ore that could be roasted, the consumption of fuel by the furnace would be lessened; and by the use of air sufficiently enriched with oxygen the necessity of using fuel might be entirely obviated. 3. Roaster gas having a higher SO2 content could be produced; this would make possible greater capacity and more economical operation of the sulfuric-acid plant. Certain phases of the application of enriched air to roasting can be worked out only by experimenting with a furnace of commercial, or at least semicommercial, size. Thus the precautions necessary to secure proper. distribution of heat in the furnace;1 the volume of enriched air; and the proportion of oxygen in this air, necessary to give the desired increase in roasting capacity of the furnace and in SO2 content of the roaster gases;; and the most desirable frequency of raking, thickness of

Jan 11, 1924

By R. B. Mears, E. H. Dix, R. H. Brown

In the Institute of Metals Division Lecture of 1940, E. H. Dix, J~.(I)~ discussed the acceleration of the rate of corrosion by high constant stresses. Experimental data obtained on this subject at the Aluminum Research Laboratories and a theory compatible with these facts were included in that lecture. The present paper contains data and ideas subsequently developed at the Aluminum Research Laboratories. Dix pointed out that in order for acceleration of corrosion by constant stress to occur: (1) There must exist in the alloy a susceptibility to selective corrosion along more or less continuous paths, as for in- stance at grain boundaries, and (2) There must exist a condition of high stress acting in a direction tending to pull the metal apart along these continuous paths. Acceleration of corrosion rate by stress is not confined to any one alloy system. Table I lists some of the metals and alloys and some of the corroding environments in which acceleration of corrosion by stress was sufficient to cause cracking (stress- corrosion cracking). It will be noted that the variety of alloys in which stress-corrosion cracking has occurred is rather large. Also, it will be observed that

Jan 1, 1945

By M. D. Cooper

For the purpose of obtaining some first-hand data in regard to the shooting down of coal in bituminous mines, it was the writer's good fortune to be employed as a shot-firer for almost one year. In all, 6020 shots were fired by him during this period. All of the work was done in what is known as the South Main section of the No. 2 Mine of the Ellsworth Collieries Co., Ellsworth, Pa., a subsidiary of the Lackawanna Steel Go. Position of Shot-firing in the Cycle of Operations The established practice of the Ellsworth Collieries Co. calls first for the undercutting of the coal by electric chain machines across the face of the entry or room. This is followed by replacing any posts removed by the machine-runners, or the setting of new posts or timber, as may be required. After this has been done the machine cuttings are loaded into cars. Then the coal is spragged, and a shot hole drilled to the depth of the undercut. Next in order, the shot-firer loads the hole and fires the charge. The working place is then cleaned up, timbered if necessary, the sides and face squared up, and loose material taken down. The face is again ready to be undercut. Materials Used Permissible explosives were used exclusively in blasting coal. These were Carbonite No. 2, a nitroglyccrine explosive; and three different makes of ammonium nitrate explosives, Tunnelite, Red H, and Mine-ite 5-D. The last-named was used during the greater part of the period. It is interesting to note that even at the beginning of this work, the gases resulting from the explosions of the charges caused no especial distress on. the shot-firer's part and this continued to be the case except on the occasions when a change was made from one class of explosive to another.

Jan 1, 1918

By R. W. Shoenberger, J. D. Clendenin, W. L. McMorris, N. Schapiro, B. R. Kuchta, A. A. Terchick, R. J. Gray, J. G. Price

INTRODUCTION * The United States is fortunate in having enormous reserves of metallurgical-grade coals. Although these coals are better in quality and more accessible than most coals found throughout the rest of the world, the best grades of these coals are being depleted. Consequently, more efficient exploration tools and techniques, such as advanced methods of core drilling and logging, correlation by palynology,** stratigraphy, paleontology and petrography are being used to help assess the extent and quality of the remaining coal reserves. Exploration and assessment of new and existing coal properties become of utmost importance in determining (1) the economic justification for mining the coal, (2) the optimum design of the preparation plant and (3) the most effective use of the coal. Fortunately, the cost of mining coal has remained stable because of better mine planning, more efficient operations and increased mechanization of mining operations. However, increased mechanization raises the amount of impurities in the coal mined, and this requires more and better coal beneficiation to meet the more stringent quality requirements set by the market. Besides, mechanical miners also produce relatively fine coal and, to ensure maximum liberation of impurities, much of the coal presently being used must be crushed to a finer size prior to preparation. The bulk of all coals presently used in this country is mechanically cleaned, much of it at a lower specific gravity than in the past. This necessitates the use of new and improved processes and equipment for coal washing and recovery, such as heavy-medium cyclones and vessels, and froth flotation cells. However, because wet-cleaning processes are pre- dominant in the United States and fine coal retains large amounts of moisture, the increased production of cleaned fine coal accentuates the need for new or improved methods and equipment for dewatering and drying this coal. The larger amounts of coal being beneficiated and the use of new and improved beneficiation processes will aid in controlling and ultimately eliminating sources of pollution. Modem coal markets demand coals that meet rigid specifications. Most coals are purchased under contracts that specify moisture, ash, and sulfur contents, or heating value, depending upon the end use. There has also been a growing trend toward specifying other properties, including particle size and coking capability. These specifications may include not only the * Editor's note: Because of the numerous and varied contributions of the associate authors of this chapter, the text does not differentiate between sections prepared by each individual as has been done in other chapters. ** Palynology is the study of plant microfossils, especially spores, pollen, and other types of fossils not usually studied by paleontologists.

Jan 1, 1968

By Robert D. Pike

IN November 1939, on behalf of the Harbison-Walker Refractories Co., the author undertook the study of the problem of utilizing the dolomite of northwestern Ohio for the manufacture of calcined magnesia suitable for use in refractories. Grateful acknowledgment is made of the unfailing assistance and encouragement throughout this work from the executive and technical staff of Harbison-Walker Refractories Company. The dolomite of the Niagara formation that is exposed or near the surface of a wide area in northwestern Ohio1 constitutes a vast supply of almost pure dolomite. It offers a virtually unlimited supply of cheap raw material of uniform dependable analysis for the manufacture of magnesia. A typical analysis of dolomite from the vicinity of Luckey, Ohio, follows: [ ] Brines containing magnesium chloride or sea water can be reacted with calcined dolomite to produce magnesia.2,3 In such reactions the MgCl2 of the brine supplies some of the magnesia and the amount of dolomite required is thereby reduced by an equivalent amount, but brines of commercial importance containing magnesium chloride are some distance away from the purest grades of the dolomite of northwestern Ohio. It was decided therefore to concentrate upon the development of a suitable process for separating the lime and magnesia of dolomite, depend¬ing upon the dolomite itself as the sole source of magnesia. This would make it possible to place a plant at the dolomite quarry, thus eliminating the cost of transporting the stone and also rendering the calcined magnesia available at a most convenient production point, considering the cost of delivery throughout the steel industry. The selection of a process depending solely upon the dolomite as a source of magnesia also necessarily entails production of the lime content of the dolomite as a by-product. It was recognized that if such a lime by-product could be produced in a suitable form, a plant location in northwestern Ohio would also be advantageous for marketing the lime. The problem, therefore, was the discovery and development of a low-cost process for separating the magnesia and lime of the dolomite of northwestern Ohio and producing each in a form relatively free from the other, and meeting the respective requirements of established markets. A satisfactory solution of this problem has been found, and it is the

Jan 1, 1947

By Edward Estabrook

THE Salt Creek oil field in Natrona County, Wyo., is the largest pool that has been found in the Rocky Mountain region and one of the largest in the United States. Many features of its production records are of peculiar interest, because of the unusual slowness with which it has been developed. This paper is published by the permission of the Midwest Refining Co., whose records have been freely drawn upon. Many mem¬bers of the Midwest organization have assisted in the collection of the material, but Messrs. F. E. Wood and L. E. Smith have been particularly helpful. The Salt Creek oil field is situated on a great dome with a closure of about 1500 ft., which rises at the northern end of a long anticline extending north-northwest by south-southeast for fully 25 miles. The productive area includes parts of townships 39 and 40 north and ranges 78 and 79 west of the sixth principal meridian. The Teapot oil field occupies a minor dome at about the center of the same anticline and adjoins the Salt Creek oil field on the southeast. The Teapot Naval Reserve includes the Teapot Dome and about 760 acres of the Salt Creek dome. In this paper, the Salt Creek oil field will be considered as' including all of the dome, except that part which lies within the Teapot Naval Reserve and the area west of the dome where oil is produced from shale crevices.

Jan 9, 1925

Discussion of the papers of Benjamin Talbot. E. A. Beck, Emil Gathmann, Sir Robert A. Hadfield, and P. H. Dudley, presented at the New York Meeting, February, 1913, and printed in this Bulletin (No. 76, April, 1913). CHAIRMAN JAMES F. KEMP :-I call upon Prof. Albert Sauveur to open the general discussion on the subject of sound steel ingots. ALBERT SAUVEUR, Cambridge, Mass. :-I believe that I have the privilege, this instant, of opening one of the most important, significant and far-reaching discussions ever held before this Institute. I believe that our talk this morning will be heard far and wide, not only on this side of the water, but also on the other side. Everywhere, in short, where steel is manufactured. I welcome the opportunity of expressing my mind in regard to the production of sound steel ingots, a subject about which I entertain some very decided opinions. I shall not attempt to discuss the relative merits of the various processes that have been described. I shall, on the contrary, confine myself to a general consideration of the important questions before us. So intensely do I feel regarding the production of sound steel ingots that I have put my remarks on paper in my desire to present my Views.

Jan 4, 1913

By Norris Johnston, Carrol M. Beeson

The gravimetric-vacuum distillation method was developed to permit rapid and accurate determinations of the oil-water ratios of small samples or sands containing little oil. In addition, the samples usually are so well cleaned and so little altered by the distillation at reduced pressure that rapid estimations of other physical properties may be made with the evacuated cores. Requiring only elementary glass-blowing technique, the distilling tubes and traps used in determining oil-water ratios were easily fashioned from the usual glassware. A sketch and description are given of the necessary apparatus, including the cylindrical electrical heaters. The procedure, requiring about 40 min., consists in raising the temperature and maintaining it between 675' and 725°F. for at least 10 min. while the pressure is held between I and 2 mm. Hg. The fluids condensed in the trap (cooled by a mixture of kerosine and solid carbon dioxide) are separated in a centrifuge and the volume of water is recorded. Determination of changes in weight with an analytical balance of all parts of the apparatus permits computation of weight of oil distilled and total weight of oil recovered. Introduction In determining the oil-water ratios of core samples, distillation at atmospheric pressurel-5 has proved to be sufficiently reliable for samples containing moderate quantities of oil. Since small samples and sands with little oil are encountered, how- ever, it appeared advisable to develop a method that would be applicable under these circumstances. Thegravimetric-extraction procedure1,6-9 undoubtedly is very reliable and could be used in all tests, but the time consumed in the determination would often delay field operations. This would be especially true when dealing with tight sands or viscous oils, both of which retard the extraction process. Accordingly, the gravimetric-vacuum distillation method was developed in order to combine the good features of both of the older methods; that is, accuracy and speed. By reducing the pressure, it was found possible to perform the distillation at a temperature that permits the use of glass apparatus, all parts of which can be weighed on an analytical balance. Thus, the fluids may be removed quickly from the core, the water is readily trapped and measured, and the loss in weight of the core is easily determined. In addition, the total weight of material condensed in the distilling tube and in the trap provides a method of determining the oil-water ratio that is practically independent of the one involving the loss in weight of the sample. The use of vacuum not only permits as much accuracy as does the gravimetric-extraction process, but it actually allows an increase in speed over the atmospheric-distillation method, because of the time required to cool the metal pots from about 1200°F. between runs. More important yet, the innovation makes possible the almost immediate reporting of permeability, and saturation, which is impossible

Jan 1, 1946

By J. H. Hollomon, L. D. Jaffe, M. R. Norton

In the practical heat-treatment of steel the decomposition of austenite usually occurs during cooling rather than at constant temperature. Nevertheless, the course of this decomposition has generally been studied only isothermally. Isothermal studies are not only simpler experimentally, but have the great theoretical advantage that one of the variables, temperature, is constant. It is the purpose of this paper to outline the principles that govern the relations between isothermal and anisothermalt‡ decomposition of austenite, to present and systematize the available experimental information, and to indicate the gaps in the existing knowledge. Some of the experimental information is the result of new work.§ Most of it is derived from scattered data in the literature. Many of these data were obtained incidentally in the course of research on other subjects and their significance has not been pointed out and perhaps not understood. It is hoped that this paper will aid future planning of more extensive research on anisothermal decomposition. Method In order to study the relations between isothermal and anisothermal decomposition, it appears fruitful to view anisothermal decomposition as taking place at a series of constant temperatures1 (except for the martensite reaction, which does not occur isothermally to an appreciable extent). When the time the steel is at each temperature is finite, the over-all amount of the reaction is considered to be the sum of the amounts occurring at each of the successive temperatures. During continuous cooling or heating, the time the steel is at each temperature and the difference between successive temperatures can be considered to approach zero. The over-all amount of transformation will then be given by integration over the range of temperatures involved. This point of view is advantageous in that it considers anisothermal transformation to be a series of isothermal transformations. The problem thus becomes one of determining the effect of partial decomposition at any given temperature upon subsequent decomposition at another temperature. Single Anisothermal Reaction Consider a phase brought to a temperature at which it is unstable, held there until it has partially transformed, and then brought to another temperature at

Jan 1, 1947

By E. C. Harder

In view of the gradually decreasing known reserves of high-grade manganese ore and the rapidly increasing consumption of iron-manganese alloys in the steel industry, it is well to turn our attention to the development of low-grade manganiferous ore deposits and to the utilization of these ores in steel manufacture. The dependence of this country on imported manganese ore and ferromanganese has been forcibly brought to the attention of steel makers during the last few years by the cessation of manganese-ore imports from Russia, the restriction of manganese-ore imports from India and of ferromanganese imports from Europe. Should the importation of manganese ore from Biazil cease, the steel industry of this country would face a serious situation. The present practice of steel making requires ferromanganese in large quantities and ferromanganese of the grade used at present can be produced only from high-grade manganese ores such as the United States appears to possess only in insignificant amounts. There are in the United States, however, large reserves of manganiferous iron ore which could probably be used extensively in the steel industry if certain changes in the practice of steel manufacture were made. Thus high-grade manganese ore could be conserved. Among the most important deposits of manganiferous iron ore in this couniry are those of the Cuyuna iron-ore district of Minnesota. It is probable that in case of restriction of foreign supplies, the users of manganese in the United States would have to rely to a large extent on the Cuyuna district to make up the shortage. Manganiferous iron ore was found in association with iron ore in the Cuyuna district in many of the early drilling operations and the possibility of its utilization was in the minds of various explorers in the dis-

Jan 1, 1918

By Norris Johnston, Carrol M. Beeson

The gravimetric-vacuum distillation method was developed to permit rapid and accurate determinations of the oil-water ratios of small samples or sands containing little oil. In addition, the samples usually are so well cleaned and so little altered by the distillation at reduced pressure that rapid estimations of other physical properties may be made with the evacuated cores. Requiring only elementary glass-blowing technique, the distilling tubes and traps used in determining oil-water ratios were easily fashioned from the usual glassware. A sketch and description are given of the necessary apparatus, including the cylindrical electrical heaters. The procedure, requiring about 40 min., consists in raising the temperature and maintaining it between 675' and 725°F. for at least 10 min. while the pressure is held between I and 2 mm. Hg. The fluids condensed in the trap (cooled by a mixture of kerosine and solid carbon dioxide) are separated in a centrifuge and the volume of water is recorded. Determination of changes in weight with an analytical balance of all parts of the apparatus permits computation of weight of oil distilled and total weight of oil recovered. Introduction In determining the oil-water ratios of core samples, distillation at atmospheric pressurel-5 has proved to be sufficiently reliable for samples containing moderate quantities of oil. Since small samples and sands with little oil are encountered, how- ever, it appeared advisable to develop a method that would be applicable under these circumstances. Thegravimetric-extraction procedure1,6-9 undoubtedly is very reliable and could be used in all tests, but the time consumed in the determination would often delay field operations. This would be especially true when dealing with tight sands or viscous oils, both of which retard the extraction process. Accordingly, the gravimetric-vacuum distillation method was developed in order to combine the good features of both of the older methods; that is, accuracy and speed. By reducing the pressure, it was found possible to perform the distillation at a temperature that permits the use of glass apparatus, all parts of which can be weighed on an analytical balance. Thus, the fluids may be removed quickly from the core, the water is readily trapped and measured, and the loss in weight of the core is easily determined. In addition, the total weight of material condensed in the distilling tube and in the trap provides a method of determining the oil-water ratio that is practically independent of the one involving the loss in weight of the sample. The use of vacuum not only permits as much accuracy as does the gravimetric-extraction process, but it actually allows an increase in speed over the atmospheric-distillation method, because of the time required to cool the metal pots from about 1200°F. between runs. More important yet, the innovation makes possible the almost immediate reporting of permeability, and saturation, which is impossible

Jan 1, 1946

By L. D. Jaffe, M. R. Norton, J. H. Hollomon

In the practical heat-treatment of steel the decomposition of austenite usually occurs during cooling rather than at constant temperature. Nevertheless, the course of this decomposition has generally been studied only isothermally. Isothermal studies are not only simpler experimentally, but have the great theoretical advantage that one of the variables, temperature, is constant. It is the purpose of this paper to outline the principles that govern the relations between isothermal and anisothermalt‡ decomposition of austenite, to present and systematize the available experimental information, and to indicate the gaps in the existing knowledge. Some of the experimental information is the result of new work.§ Most of it is derived from scattered data in the literature. Many of these data were obtained incidentally in the course of research on other subjects and their significance has not been pointed out and perhaps not understood. It is hoped that this paper will aid future planning of more extensive research on anisothermal decomposition. Method In order to study the relations between isothermal and anisothermal decomposition, it appears fruitful to view anisothermal decomposition as taking place at a series of constant temperatures1 (except for the martensite reaction, which does not occur isothermally to an appreciable extent). When the time the steel is at each temperature is finite, the over-all amount of the reaction is considered to be the sum of the amounts occurring at each of the successive temperatures. During continuous cooling or heating, the time the steel is at each temperature and the difference between successive temperatures can be considered to approach zero. The over-all amount of transformation will then be given by integration over the range of temperatures involved. This point of view is advantageous in that it considers anisothermal transformation to be a series of isothermal transformations. The problem thus becomes one of determining the effect of partial decomposition at any given temperature upon subsequent decomposition at another temperature. Single Anisothermal Reaction Consider a phase brought to a temperature at which it is unstable, held there until it has partially transformed, and then brought to another temperature at

Jan 1, 1947

ABOUT 2 lb. of alumina (aluminum oxide) of high purity is required to produce a pound of metallic aluminum. Projected production of metallic aluminum in the United States is now seven to ten times the peacetime rate a few years ago. In the past, all the alumina for aluminum production in the United States has been obtained from bauxite. Part of the bauxite was mined in the United States--chiefly in Arkansas-and part was imported from Surinam. All of it was chemically treated in the United States to separate the greater part of the aluminum oxide from the bauxite, alkaline solutions being used, in a method known as the Bayer process. The ingredients of the bauxite other than alumina, such as the compounds of iron titanium, and silicon, constitute the tailings from the Bayer-process operation. This product contains sufficient iron to give it a red color and hence it is called "red mud." Lime and soda used in the processing, are also present. Varying amounts of alumina remain in the red mud, depending upon the characteristics of the bauxite, the effectiveness of the treatment, and in particular upon the amount of silica originally present in the bauxite. High-silica bauxites result in high alumina loss in the red mud.

Jan 1, 1942

By T. Saburi, C. M. Wayman

The massive and martensitic transformations in ß Cu-Ga alloys were studied by optical microscopy and by transmission electron microscopy and diffraction. These types of transformation are distinct and do not merge into one another. An internal fine structure due to stacking faults was found in both the massive phase (m) and the martensite, but the origin of the faults is believed to be different in each case. The faults in the martensite are due to the lattice invariant or "second" shear of the phenom-enological theory, while those in the are probably growth faults and deformation faults arising from the transformation volume change. Evidence is presented for ordering in the ß phase prior to transformation into martensite, and the crystal structures of and ß' and ßi martensites are discussed. THE results from some previous investigations1,2 have led to the suggestion that martensitic and massive transformations have certain common characteristics. It presently seems established that massive transformations like martensitic transformations are essentially diffusionless,1,2 but unlike martensitic transformations, when a new phase forms massively there is no shape change or surface relief.= If the massive-type transformation is crystallographically similar to martensitic transformations, one would expect a fine structure as a result of the lattice invariant shear4 which is a part of the transformation mechanism. The existence of such a fine structure (i.e., slip, twinning, or faulting), if any, can be verified by transmission electron microscopy, and thus the present investigation was undertaken to compare the internal structure of massively and martensitically formed phases in Cu-Ga alloys which were derived from a parent of the same composition. The transformation characteristics of ß Cu-Ga alloys were also studied. The bcc ß phase in the Cu-Ga system, Fig. 1, is stable above 616oc.' Depending upon the cooling rate, ß Cu-Ga alloys can undergo three different types of phase transformations. The ß phase of eutectoid composition (23.7 at. pct Ga) decomposes into the ? phase (hcp) and the phase (complex cubic) by means of a eutectoid reaction. When the cooling rate is increased so that the decomposition of 0 into [ and ? is suppressed, the ß phase transforms into a nonequilibrium hcp phase, herein denoted ?m by a process of very rapid growth called a "massive" transformation. At even faster quenching rates the massive transformation can be suppressed and the ß transforms martensitically. Massive transformations, apparently similar to those in the Cu-Ga system, have also been studied in the Cu-Zn2,6-8 and Ag-Cd systems.9 Definitive characteristics if the Massive Transformations in 0 Cu-Ga Alloys1 1) The most remarkable feature of the massive transformation in Cu-Ga is that there is no bulk composition change on transformation. According to Massalski,1 the resulting [, phase is a supersaturated extension of the equilibrium [ phase. The lattice parameters continue the trend exhibited

Jan 1, 1965

By H. O. Hofman

The substance of this paper was prepared for the Seventh International Congress of Applied Chemistry, held in London, May, 1909, under the title, Some Developments in Blast-Roasting. In the absence of the author, a short abstract of the paper was read, and the abstract only will appear in the proceedings of the congress. The present paper has been partly rewritten and considerably enlarged by information gained since the original was prepared; also some illustrations have been added. Blast-roasting* is a generic term for the process of forcing air through finely-divided metallic sulphide with the object of roasting and agglomerating in a single operation. At first the process was confined to a galena-concentrate; lime, limestone, or gypsum was added, to serve both as a diluent to keep separate the particles of galena that they might be thoroughly oxidized, and as a flux that the partly-roasted ore niight be agglomerated by the formation of some slag. Later it was extended to treat other metallic sulphides. The leading processes were the Huntington-Heberlein and the Savelsberg of Europe, and the Carmichael-Bradford of Australia. In the United States and Canada, the Huntington-Heberlein process has found application in some instances with galena-concentrates, for which it was originally intended; but this class of ore is not often treated alone, hence the process has had to be modified to suit conditions. The Savelsberg process has been transplanted to this country in about its original form. The Carmichael-Bradford is not used at present. The changes called for in the Huntington-Heberlein process to adapt it to the class of lead-bearing ores usually smelted have been the

Jan 1, 1911

By C. L. Mantell

ALTHOUGH SO common and well known a metal, tin is really a less abundant element than many of those less familiar and usually ranked with the scarce or rare elements, such as cerium, yttrium, lithium, beryllium., titanium, zirconium and vanadium. The color of tin is white, with a slightly bluish tinge. When it is compared with nickel, the latter metal is brown. When placed alongside of tin, chromium is definitely blue. Tin is whiter than silver or zinc. Exceedingly thin films of tin show various shades of brown by transmitted light. The metal has a brilliant luster, and when mirror-polished, has high light reflectivity. The luster depends to a large extent upon the pouring temperature at which the metal is cast. If the temperature be, too high, iridescent colors may show on the surface. These are the result of oxide film formation. If the pouring temperature be too low, the surface is dull. Small amounts of foreign metals, such as lead, arsenic, antimony and iron, decrease the luster of tin and impart a yellowish tinge to the metal. The structure is decidedly crystalline. The cast metal is a mass of crystals. When a bar of tin is bent, it emits a characteristic creaking sound. This is called the "cry" of tin, resulting from the grinding of the crystals one against the other during the bending of the metal. Tin metal may lose its crystalline structure by cold working, but grain growth occurs rapidly under the influence of heat. Metal which has been cast at a low temperature may become amorphous as the result of mechanical work. If such material be heated to temperatures well. below the melting point, say at 110° C. for a half hour or for a few minutes at 150° C. recrystallization occurs. If the surface of tinned plate, tin foil, or tin metal in cast form be etched with hydrochloric acid containing a little free chlorine, attack occurs at the intercrystalline faces. The surface shows patterns resembling the frost flowers on window panes in winter. The etched appearance is called moiré metallique. Fine dendritic surface crystals of tin may be obtained by casting the metal on a surface of polished steel. In commercial tin plate, the intercrystalline boundaries are shown by fine grooves or channels, which result from the method

Jan 1, 1929

By F. Keller, J. D. Edwards

The anodic treatment of aluminum presents problems of scientific as well as of commercial interest.l-3 Of particular interest is the fact that, during the anodic oxidation process, the oxide continues to form at the metal-oxide interface under any oxide previously formed. This has led to speculation as to the mechanism involved in the formation of the relatively thick oxide coatings that are used commercially for decorative or protective purposes. Furthermore, the ability of certain types of oxide coatings to adsorb dyes and other substances has stimulated research to determine the actual structure of these adsorptive coatings. It has been found that anodic oxide coatings on aluminum are composed essentially of aluminum oxide. They are formed by the action of oxygen ions penetrating to the metal surface during the electrolytic oxidation treatment. These coatings can be formed in a number of different electrolytes, as for example, those which contain sulphuric acid, chromic acid, oxalic acid, or boric acid. These are the commonest and most useful electrolytes employed commercially. Except for certain specific conditions of formation, the coatings in general have been found to be amorphous alumina, as far as can be determined by X-ray or electron-diffraction methods. Anodic oxidation processes can be arranged in three rather general classes if they are grouped in relation to the solvent action of the electrolyte on the coating.4 In the first class, the electrolyte has little or no solvent action on the coating that is formed. In general, coatings produced under such circumstances are nonporous and non-adsorptive. In the second class, the electrolyte exerts an appreciable solvent action on the coating. These coatings are porous and adsorptive. Finally, for the third class, the electrolyte tends to dissolve the coating about as rapidly as it is formed. This action produces electrolytic brightening or anodic polishing of the aluminum surface and at most leaves only a very thin film of oxide. The nonporous and nonadsorptive type of oxide film is represented by the coatings that are formed when solutions of boric acid are employed as the electrolyte. It is especially significant that these impervious films are formed in electrolytes that exert little or no solvent action on the coating. Where a boric acid electrolyte is used, the coating tends to form rapidly, with the result that the flow of current is soon reduced to substantially zero. This indicates that the growth of the coating has stopped. As a rule, the thickness of the coating is roughly proportional to the voltage employed for formation and the coatings of this type are exceedingly thin. In an electrolyte of this type, the coating has a high resistance when the aluminum is made anode; consequently, any current that may flow (leakage current) is very

Jan 1, 1944