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By H. J. Struth

In these trying times of proration and low oil prices, it is decidedly necessary for all branches of the petroleum industry to accord full recognition to the economic phenomena that contribute to its varying state of welfare. Perhaps no other single factor has a more important bearing upon the general oil situation than the supply and demand of gasoline. Year after year, the records have shown that the degree of prosperity or depression accompanying the industry's developments has been to a large extent influenced by the degree of balance maintamed between the supply and demand of gasoline. More and more it is being realized within the industry that equilibrium between the supply and demand of gasoline forms the basic structure of crude and product market values and, consequently, the deciding factor in the financial results of the industry as a whole. The influence of the gasoline situation upon the market and financial structure of the petroleum industry was effectively demonstrated during 1930, when excess accumulation of gasoline undermined not only the refined oil market but the crude market as well. In fact, it was a top-heavy gasoline situation that defeated the realization of benefits that might have accrued from an otherwise favorable statistical position in the producing branch of the industry. Indicative of this is the fact that crude oil production was curtailed to the extent of 98,323,000 bbl. last year, while refinery runs to stills were maintained at an excessive rate until late in the year, creating an excess gasoline production of 6,663,000 bbl. above actual requirements. Nevertheless, the movement to curtail refinery operations during the closing months of the year prevented a far worse situation, although it came too late to turn the ebbing momentum of the general oil market. Despite the severe depression of the market values that accompanied 1930 developments, it can be said that the results attained during the closing months of the year, in the direction of production control, marked a decisive turn in the industry's economic affairs. In fact, a review of the oil situation from every angle points definitely to a better general understanding and recognition of the workings of the economic law of supply and demand. As a result, the year closed with crude production in

Jan 1, 1931

By Whitman E. Brown, Louis J. Erck

The installation in 1948 of a Hum-phrey~ spiral concentrator section at the Hill-Trumbull plant of The Cleve-land-Cliffs Iron Co. is the latest commercial method on the Mesabi Range being used for the recovery of fine iron ore. In two stages of concentration 84 spirals treat approximately 120 long tons per hour of minus ? in. ore. These spirals augment the production of the heavy-density plant which recovers the plus 36 in. iron from the plant crude ore. Structure of the ore is such that, when crushed, about 50 pct of the plant crude is minus ? in. size. After de-sliming in a 66 in. Akins classifier, grinding the classifier product in a ball mill and again desliming in a 78 in. Akins classifier about 15 pct of the crude ore remains to be treated in the spiral plant. Overall recovery of the ball mill feed in the Hill-Trumbull spiral plant during the 1948 season was about 53 pct of the weight and 66 pct of the total iron content. Of the actual feed delivered to the spirals from the 78 in. classifier 64.9 pct of the weight was recovered containing 73.7 pct of the total iron. The average analysis of the spiral concentrate is 55.05 pct Fe and 14.83 pct SiO2. An average of mill assays during the 1948 season is given in Table 1. The Hill-Trumbull plants treat both wash ore and jig-type ore. During the 1948 season spirals were used only on the fine sizes of jig-type ore. At times the deslimed minus ? in. size is of sufficient grade to warrant bypassing the spirals but in the main the fine size is delivered to the 48 first stage spirals and thence to the 36 cleaner or second stage spirals. In the past several years numerous Mesabi Range ores in the fine size cate- gory have been tested by a wide variety of beneficiating equipment. The prodigious amount of research devoted to the recovery of values in the fine ore reflects the dire need of the iron industry to squeeze the last possible unit of iron from the mined ore and to develop suitable equipment and processes to satisfactorily concentrate the leaner horizons as they are encountered in the process of mining. Large governmental and private appropriations have been allotted, new laboratories built, research and technical staffs increased, and operator-manufacturer cooperative agreements applied to hasten the solution of the problem. The University of Minnesota, at its Eighth Annual Mining Symposium in January 1947, dedicated as its objective the bringing to light of technological developments in iron ore beneficiation. Papers were given at that time relating to processes being developed. Specifically, these papers reviewed flotation, Baum jig, selective media concentrator, Hardinge concentrator, Dorrco sizer, heavy media concentration, Hydrotator, and the Humphreys spiral. The Cleveland-Cliffs Iron Co., after encouraging results from tests in a small pilot plant using one full size spiral, made the first commercial installation of Humphreys spirals on the Mesabi Range at their Hill-Trumbull mine, Taconite, Minn. This company

Jan 1, 1950

By C. R. King

Most of the acid volcanic glasses such as obsidian, perlite, pitchstone, pumice, and pumicite (volcanic ash) are susceptible to some expansion if suddenly subjected to a suitably high temperature in a properly designed furnace, and subsequently suddenly cooled. Expansion results from the action of chemically combined or dissolved water expanding as a vapor within the softened heated rock particles. This expansion forms countless minute bubbles within the pasty mass of the natural glass particles. If the particles are cooled before these bubbles can escape, the resulting products are cellular, more or less spherulitized glass froths or hollow glass spheres of many types. Chemically, they are essentially aluminum silicates containing about 70 to 75 pct silica, 10 to 16 pct alumina, and 2 to 7 pct sodium plus potassium oxides. They are relatively resistant to attack by acids or alkalies, are resistant to heat up to over 1000°F, and are completely inert to insect or fungus attack. These products are of great potential value in many branches of industry as insulation materials, aggregates, fillers, abrasives, and additives. By proper selection of the perlite rock type and control of processing conditions, expanded perlite of a bulk density varying from about 2 to 20 Ib per cu ft can be • made. The physical properties of the particles comprising a product of a given bulk density also may be varied within wide limits of porosity, water absorption, and crushing strength. In general, crushing strength of expanded perlite increases in direct relation to increase in bulk density, but insulating value varies in inverse ratio to bulk density. The selection of a particular grade of expanded perlite for a given use as an aggregate is therefore always a compromise between insulating value, lightness, and friability. If porosity and water absorption are factors affecting the use of the material, factors other than bulk density are important. Some types of perlite rock tend to decrepitate excessively during expansion, resulting in a highly porous or even hygroscopic product of high friability relative to the bulk density of material produced. In general, treatment of any good perlite rock below the temperature necessary for maximum expansion, or insufficient time in the hot zone of the furnace for effective heat penetration to the core of the rock particles will result in some decrepitation and high porosity in the expanded product. On the other hand, exposure of the material to the temperature required for optimum expansion for a period of time slightly longer than that necessary for proper heat absorption will result in a slightly heavier product of extremely low porosity, i. e., a glazed surface. It is beyond the scope of this paper to describe in detail the rock types and processing methods used to produce the many types of expanded perlite in present use, or that may be produced to fill the present and future needs of industry. A few phases of the economics involved in processing and selling products made from this abundant and cheap mineral raw material, plentifully distributed in large and relatively accessible deposits in most western states and in other areas within economic shipping distance of large centers of consumption, will be treated with particular reference to the Los Angeles area. Relation of Balk Density to Use and Cost of Production Perlite differs from most other lightweight aggregates and fillers in that the raw material (perlite rock) may be quarried much as rock arid sand is mined, and then shipped into consuming areas as crude rock in open gondola cars at correspondingly low freight rates and handling costs. At processing plants in or near large consuming areas the rock is converted into relatively fragile, very bulky products which in most cases are used within a short haul of the processing plant or enter into a manufactured product made at the site of the perlite processing plant.

Jan 1, 1950

By W. F. Stowasser

downdraft traveling grate process to agglomerate pelletized iron ore concentrates has been successfully demonstrated in a pilot plant at Carrollville, Wis. Work there followed several years of development in the Allis-Chalmers Mfg. Co. laboratories, and the pilot plant phase was carried out in cooperation with Arthur G. McKee & Co., consultants and engineers to the iron and steel industry. End result of the process is conversion of iron ore concentrates into a form which can easily be transported and smelted in the blast furnace. Process Description The first of two process steps incorporates the art of balling and prepares the concentrates for burning. The second step consists of burning the green balls on the grate machine to the hardness required for shipping and handling purposes and for reduction in blast furnaces, see Fig. 1. Facilities are provided at the pilot plant to receive carload quantities of concentrate. The concentrates are loaded into a 50-ton bin direct from railroad cars. Because of the variable moisture content of the concentrates after shipment in an open railroad car it is necessary to repulp and refilter the concentrates to maintain a uniform and proper moisture content for the balling operation. Concentrates are conveyed to slurry tanks, and the slurry, at 50 to 60 pct solids, is pumped to a 4x4-ft drum filter. The filter provides feed of uniform moisture to the plant. Magnetite concentrates are normally filtered to produce a cake containing about 10 pct moisture, a necessary requirement for the following balling operation. The filtered concentrate is conveyed to a rotary bin table feeder which acts as a surge bin for the filter cake and delivers a steady flow of concentrates to the balling drum. It is often desirable to make additions to the concentrates as they are fed to the balling drum. These additives, such as bentonite, increase the strength of the finished green pellet and improve ballability of the concentrate. A vibrating feeder supplies additive to the feed belt, and the additive is mixed with the concentrate in the balling drum. The balling drum, shown in Fig. 3, is 8x3-ft diam. An oscillating cutting bar maintains the lining in the drum by trimming off the buildup of excess concentrate as it forms. The drum is operated in closed circuit with a lx4-ft rod-deck vibrating screen. Undersize pellets or seed pellets from the screen are returned to the balling drum until they grow to the desired size. Size of pellets is controlled by the opening in the screen deck. The formation of pellets in the balling drum is affected by many variables. Some of these are: the size distribution of the feed, the particle shape of the concentrate, the feed rate to the drum, the moisture in the concentrate, the speed of rotation of the drum, the slope of the drum, and the type of trimming obtained with the cutting bar. In this process, attempts are made to control the pellet size within the limits of % to 5/8 in. diam. The screened oversize pellets are conveyed under a coal feeder where sufficient powdered coal is added to the belt to produce desired results in the burning process. The top size of the coal successfully used has been 20 mesh, and anthracite was used in the test program. Fig. 4 illustrates the vibrating screen and the coal feeder. The pellets and free coal are conveyed together to the 5x3-ft diam- reroll drum that rolls the coal onto the surface of the pellets. This drum is also equipped with a cutting bar. The prepared pellets, containing bentonite, water, and surface coal, are elevated to the traveling grate, which consists of a continuous strand of 37 pallets. Each pallet, with a grate bar area 2 ft wide by 1 1/2 ft long, has 14-in. high side plates, Fig. 5. Feeding and distribution of the green balls to the grate is handled by a short conveyor which oscillates back and forth across the 2-ft width of the grate. An adjustable vertical plate located several inches in front of the head pulley of the oscillating conveyor controls the height of the bed and levels the moving bed of pellets. This method of feeding prevents segregation of various size pellets as well as fines and produces a uniform, permeable bed. The pallet train moves under the furnace and across four windboxes, located beneath the pallet frames, see Fig. 2. As the green pellets are deposited on the grate, partial drying of the pellets begins over a 2-ft long updraft windbox. The low temperature air reduces the moisture in the pellets in the lower level of the bed and this operation is essential to prevent sagging of the bed during later stages of the Process. The air used for this drying is recuperated from cooling the pellets on the grate, and supplemental heat, required for starting the Process, is obtained from an auxiliary burner. The pellets are then moved by the grate into the furnace and over an 8-ft windbox, designated as the downdraft waste windbox. Products of combustion are exhausted from this windbox to atmosphere. The furnace, shown in Fig. 6, is constructed with three chambers to provide downdraft drying, preheating, and ignition, respectively, to the pellet bed as it passes through. Overall length of the furnace is 5.57 ft; however, the exterior wall ends may be moved to reduce the length and also adjusted to Obtain the bed height desired, The drying, preheating, and ignition sections of the furnace are supplied with medium temperature

Jan 1, 1956

By E. A. Gulbransen, J. W. Hickman

INTRODUCTION DURING the past two decades considerable progress has been made in the art of manufacturing heater alloys. The conventional iron-chromium-nickel alloys have been improved by the addition of small quantities of other elements. Up to the present time, to our knowledge, there has not appeared a systematic study of these alloys where the newer tools of investigation have been brought to bear on the problem. It is not yet clear what roles the additional elements play in increasing life time in usage. As a first approximation one might guess that elements such as manganese, silicon, zirconium, calcium and aluminum would aid in the formation of a protective film on the alloy surface, thus retarding the oxidation rate and increasing lifetime. If these additional elements do form protective oxides in the outer surface of the oxide film, it may be possible to identify them by means of reflection electron diffraction. It is also possible that the additional elements may not diffuse to the surface but may remain at the interface between the oxide and the metal. Then, too, the major elements in the alloys undoubtedly form oxides which are stratified on the surface. If the minor elements concentrate in a layer in contact with the substrate where they undergo oxidation and if this oxide film offers resistance to the diffusion of iron, chromium and nickel ions, then the lifetime of the heater element might be expected to increase. It is also possible that preferential reduction in the diffusion rates of the several ions may occur to such a degree that oxides may form in the body of the film and on the outer surface which are different from those that would normally form if the additional elements were not present. The use of transmisson electron diffraction may aid us in interpreting these phenomena. Up to the present time all of the factors which influence the lifetime of a given heater element are not definitely known. Among these are: (I) The rate of oxidation of the alloy. This may be dependent upon the composition and the physical state of the alloy. (2) The stability of the structure of the coating which forms. Transitions from one structure to another or solid phase reactions resulting in a change of composition may occur. The tendency of the film to adhere to the substrate when heated and cooled successively will be important. (3) The evaporation of various constituents from the alloy such as the removal of carbon by oxygen in a decarburization reaction. With these possibilities in view, an electron diffraction study of the oxides occurring on six different nickel-chromium alloys was undertaken with the hope that the results of this study could be correlated with oxidation rate studies as determined by means of the vacuum microbalance method1 and with

Jan 1, 1948

By Eizo Yabuuchi, Yukito Imanaga

INTRODUCTION In treatment of mine drainage, it is well known that the neutralization by calcium carbonate is far better than by slaked lime because of cheaper cost and better precipitability of its deposit. However, in case of iron ion contained in the mine drainage consists of ferrous salt, the ferrous salt must be oxidized to ferric salt before neutralization, because the ferrous salt does not react with calcium carbonate. At Yanahara Mine, during the period of 1950 through 1956, ferrous ion in the mine drainage had been oxidized to ferric ion, simultaneously neutralized by adding calcium carbonate into the aerated drainage. During the period of 1961 through 1974, after passing through many kinds of treating methods, the neutralization had been carried out by addition of calcium carbonate into the drainage after oxidized its ferrous ion to ferric by using nitrous gas as an oxidizing catalyzer. Meanwhile we had made an experiment on the oxidation of ferrous ion by utilizing iron bacteria, and developed a method which oxidized ferrous ion in large quantities briefly by cultivating and concentrating iron-oxidizing bacteria. Since 1974, we have been operating successfully for treating the drainage at Yanahara Mine by means of utilizing these bacteria.

Jan 1, 1976

By N. Brown

From the theories of flow and fracture it is shown that the difference in reciprocals of the transition temperatures (OK) is a quantitative measure of temper ernbrittlement. Experimental data are given which support this conclusion. STUDIES of temper embrittlement have been made with various viewpoints; some involved a study of the kinetics of the reaction,',2'" others were concerned with changes in the mechanical properties," . and still others investigated the structural differences between the embrittled and unembrittled states by means of the microscope," -ray ,' measurements of electrode potential," and electrical resistivity." In all these studies, the difference in impact properties was the criterion for distinguishing between the embrittled and unembrittled states. By common agreement the difference in transition temperatures is now taken as a measure of the degree of embrittlement, and this measure is used as the quantitative measure upon which studies of the phenomenon are based. Vidal and Jolivet"' suggested that the degree of embrittlement was the same whether measured by impact or by a slow bend test. Their conclusion was based on tests at constant temperature. Jaffe and Buffum" using the impact and slow bend test showed that, for a given degree of embrittlement, the difference in transition temperatures varied with the method of testing. Hultgren and Chang" showed that the difference in transition temperature produced by the V-notched Charpy impact test was not the same as the value produced by the keyhole-notched impact test. This is a very fundamental point because there can be no true measure of temper embrittlement unless it is invariant with respect to the test method. Theory The purpose of this analysis is to show how the transition temperature depends on the stress distribution and the state of the material. The criterion for fracture may be stated as follws: where iF is some function of the principle stresses and F is a critical condition depending on the state of the metal. Similarly yielding occurs when Where is another function of the prin-ciple stresses and Y is a critical value depending on the state of the material. There is some controversy as to the exact form of the function f,.(u,, u,, us) but most experimental data give the following criterion:= where 8, and 6, = 21 or 0. Combinations of 6, and 8, give the various criteria such as the normal stress, the hydrostatic tension, and the maximum shear stress laws. Agreement is general that the octahedral shear stress law adequately describes the yield condition. where the bracketed factor will be called the design factor and depends on the stress distribution. Whether the metal decides to yield or fracture is given by the condition that The effect of temperature and strain rate upon Y has been studied by various investigators, It has been shown by MacGregor and Fisher" that

Jan 1, 1955

By Roscoe C. Clark

A study of the effect of various corrosive waters on five different types of cements indicated that those cements containing less than 5 per cent tricalcium aluminate were the most resistant to corrosion. INTRODUCTION Oil field experience indicates that some formation waters are excessively corrosive to some cements. A study has been made to determine the most corrosive waters and the relative resistance of various types of cement to these corrosive waters. PROCEDURE This study of the corrosion of cement was limited to an evaluation of the effect of various corrosive waters on five different types of cements. A determination was made of the types of cements which offer the greatest resistance to corrosion and of the chemical contents of waters found to be the most destructive to cements. The laboratory tests were conducted by immersing small cylinders of 20 samples of set cement in various corrosive waters. The initial mixing of most of the cement slurries was done using Tulsa tap water as the mixing water; however, a few of the slurries were mixed using a sulfate water as the mixing water. When the 20 samples had been immersed for a period of nine months, they were removed from their corrosive baths, inspected and photographed. The field tests were conducted by placing ten cement specimens, each contained in a screen wire thimble, in the gas anchors of insert pumps in wells in six different fields. The specimens were observed whenever it was necessary to pull the pumps and were returned to the 1aboratory when deterioration had reached a serious state. EXPERIMENTAL RESULTS In both the field and laboratory tests the resistance of the different cements to corrosion was determined by the condition of the samples and the number of samples of each that were in good condition at the end of the immersion period. Table I lists the various cements tested in the order of their resistance to corrosion with the most resistant at the top and the least resistance at the bottom. An analysis of Table I reveals that the upper half of the table predominates in slow set and sulphate resisting cement.: (low 3CAO.A12O3 content) while in the lower half the port-land and high early strength cements are in the majority. Of the last two the high early strength cements appear to offer less resistance to sulfate water corrosion. An investigation of the composition of the cements listed in Table I indicated that as a general rule the cements containing less than five per cent tricalcium aluminate will exhibit the greatest resistance to corrosion. The destructive action of various corrosive waters was compared by listing the waters in the order of those containing the largest number of samples that failed completely. These ratings are presented in Table II with the most corrosive waters listed first and the least corrosive last. Figs. 1 and 2 show the end views of cement samples which had been immersed in the baths of five per cent MgSO, water and the five per cent Na2SO4 water respectively in the laboratory. These .pictures are representative of the results obtained and present a pictorial evaluation of the corrosive resistance of various types of cements.

Jan 1, 1950

After the close of the Revolution, settlers began to pour over the mountains, to settle in the western parts of Pennsylvania, of Virginia, to move down the Ohio into Kentucky, and in the late seventeen-eighties to settle on "the Indian side" of the river, now Ohio. With the growth of population the interest in coal increased and it was not long before the production of coal west of the mountains was larger than that east of them. Foreign nations, too, became interested in the young republic and in 1783, at the instance of the Swedish government S. A. Hermelin, an engineer, visited this country to investigate its iron industry. He made a very interesting report, not published until 1931, in which he gave many details of the iron plants in the eastern United States; apparently he was not west of the mountains, but was well informed about conditions there. He says, "that some coal near the first branches of the Schuylkill River has been mined and utilized by the blacksmiths," referring, of course, to anthracite; again that "coal mines have also been worked for several years near Pittsburg," and that "great supplies of iron ore are available at the Ohio Falls and further to the west, at Coney Creek, a part of the Green River, where there is also coal."' In 1788, Dr. Johann David Schoepf, who came to this country with the Hessian troops, visited Pittsburgh. He was an intelligent man and acquainted to some extent with minerals and methods of working them. In speaking of Coal Hill on the south side of the Monongahela he mentioned several strata of marble in the lower part and that

Jan 1, 1942

By Herbert Haas

GEORGE W. HAWKINS, Tucson, Ariz. (communication to the Secretary*).-The paper by Mr. Haas will no doubt be followed with considerable interest, as it covers the power-plant problem in quite a comprehensive way, including not only the usual operating costs but also the fixed charges on the investment, and for load factors ranging all the way from 25 to 100 per cent. and fuel oil ranging from $1.25 to $2 per barrel. The very fact, however, that his paper does cover such a wide range of conditions, makes it the more imperative that any conclusion drawn from his analysis be very carefully considered for any specific case, for in making such analysis the type of prime mover and size must be selected for some one condition which might not be the proper selection had some other condition been assumed as the basic one, resulting in an unfavorable comparison under all conditions except that condition assumed. From the reasons given by the author for his selection of the large turbine units, it is evident he had in mind very high load factors, ranging

Jan 12, 1916

By Thomas V. Falkie

The use of operation research and computer techniques in the mineral industries continued to gain acceptance during 1966. There are generally at least five sources of information for researchers and practitioners in the field: (1) Technical periodicals like MINING ENGINEER- ING, Mining Congress Journal, etc. (2) Proceedings of the Symposium and Short Course on Computers and Operations Re- search in Mineral Industries, held last year at Penn. State University and jointly sponsored by the University of Arizona, Stanford University, Colorado School of Mines, Penn. State University and the Society of Mining Engineers of AIME. (3) Various local conferences, such as the 1966 Rocky Mountain Minerals Conference held in Denver. (4) United States Bureau of Mines publications. (5) The AIME annual meeting in New York and the SME Fall Meeting in Tampa.

Jan 2, 1967

By Maynard O. Serbousek, James R. McVey

IS there a quick way of assessing the conditions of a newly exposed roof in a coal mine? This has always been a nagging question. The problem is that unless effective controls are established as soon as possible, it becomes extremely difficult to extract coal safely and economically from conventional underground milling operations. Until recently, little has been done to provide a means of measuring the structural behavior of a coal mine roof while the face advances during actual production. (In fact, most measurements have always been made after the fact or during a roof pull-down where the roof is actually caused to fail with no support.)

Jan 9, 1976

APPROXIMATELY 90 per cent of the steel that is melted and refined in the United States and poured into ingots is made in basic open-hearth furnaces, as shown in Table 1-1. The annual ingot capacity of the steel industry reported January 1,1950, by the American Iron and Steel Institute8* was 99,040,160 tons, of which the basic open-hearth process accounted for 85,896,580 tons, 86.7 per cent of the total. The capacity of the individual furnaces varies over a wide range, a large majority falling within limits of 50 to 200 tons (Fig 1-1). Most of the units constructed [ ] since 1942 are in the larger size groups, between 175 and 225 tons capacity.

Jan 1, 1951

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and guests who registered at Institute headquarters during the period Sept. 10 to Oct. 10, 1914: James D. Mooney, Akron, Ohio. J. Kojima, Ashio Copper Mine, Japan. Bernard A. Wilkinson, Guadalajara, H. Starkweather, Cripple Creek, Colo. Mexico. S. S. Langley, New York, N. Y. A. B. Parsons, Candor, N. C.. J. H. Warder, Chicago, Ill. Arthur Feust, Santo Domingo, Nicaragua. Lloyd T. Buell, Butte, Mont. G. B. Marshall, New York, N. Y. George R. Rogers, Gowganda, Canada. Henry Krumb, Salt Lake City, Utah. H. 0. Hammond, Douglas, Ariz. Herbert S. Kohlberg, El Paso, Texas. Percy E. Hohne, El Oro, Mexico. Wilbur L. Cross, Jr., Glen Carbon, Pa. Percy E. Barbour, Candor, N. C. Thomas H. Leggett, formerly-in charge of the mining interests of the American Smelting & Refining Co., has resumed practice as consulting engineer with offices in the Singer Building, New York, N. Y.

Jan 11, 1914

By Gilbert Soler

Producers of alloy steels recognize the importance of chemical composition in relation to the hot-working properties and the typical surface defects found in their product. Each analysis of steel has its own peculiar characteristics. Under conditions of standard mill practice each analysis is susceptible to certain types of defects. Mill practice must be varied to obtain the best combination of surface and internal quality in the product. Chemical composition influences the cast structure and crystallization characteristics of the ingot. It also determines the rate of heating and cooling, the plastic hot-working range, and the phase structure of the steel at various temperatures. as well as the tendency toward scale formation and decarburization. This paper endeavors to emphasize the manner in which chemical composition affects the various properties of steel, and to indicate the relative importance of these factors in relation to the hot-working properties and surface characteristics of killed steel. The influence of chemical composition may be outlined as follows: I. Effect on the cast structure of steel, including: A. State of deoxidation, and type of inclusions. B. Gas content of steel. C. Freezing point and melting point of steel. D. Crystallization characteristics and segregation. 11. Effect on the hot-working properties and surface characteristics of steel, including: A. Plastic hot-working range. B. Phase structures at hot-working temperatures. C. Rate of heating. D. Cooling characteristics. E. Scale formation. F. Surface decarburization. EFferect of Chemical Composition on Cast Structure of Steel State of Deoxidation and Type of Inclu-sions.—The state of deoxidation is limited by the final chemical analysis desired in the finished product, and is controlled primarily by carbon, manganese, silicon, and aluminum, and to a lesser degree by chromium, titanium, vanadium, or other deoxidizing elements. The degree of deoxidation affects the density of the cast structure and broadly classifies the steel as killed, semikilled, or rimming. This in turn manifests itself in surface characteristics. The manner and extent of deoxidation also controls the amount, type, and distribution of nonmetallic inclusions formed. The equilibrium of manganese, silicon and aluminum with the slags and pouring refractories with which the metal comes in contact is important, especially in regard to inclusions of fire-clay origin. Some surface Seams and hot-working difficulties can be traced to nonmetallic inclusions.

Jan 1, 1941

By Gilbert Soler

Producers of alloy steels recognize the importance of chemical composition in relation to the hot-working properties and the typical surface defects found in their product. Each analysis of steel has its own peculiar characteristics. Under conditions of standard mill practice each analysis is susceptible to certain types of defects. Mill practice must be varied to obtain the best combination of surface and internal quality in the product. Chemical composition influences the cast structure and crystallization characteristics of the ingot. It also determines the rate of heating and cooling, the plastic hot-working range, and the phase structure of the steel at various temperatures. as well as the tendency toward scale formation and decarburization. This paper endeavors to emphasize the manner in which chemical composition affects the various properties of steel, and to indicate the relative importance of these factors in relation to the hot-working properties and surface characteristics of killed steel. The influence of chemical composition may be outlined as follows: I. Effect on the cast structure of steel, including: A. State of deoxidation, and type of inclusions. B. Gas content of steel. C. Freezing point and melting point of steel. D. Crystallization characteristics and segregation. 11. Effect on the hot-working properties and surface characteristics of steel, including: A. Plastic hot-working range. B. Phase structures at hot-working temperatures. C. Rate of heating. D. Cooling characteristics. E. Scale formation. F. Surface decarburization. EFferect of Chemical Composition on Cast Structure of Steel State of Deoxidation and Type of Inclu-sions.—The state of deoxidation is limited by the final chemical analysis desired in the finished product, and is controlled primarily by carbon, manganese, silicon, and aluminum, and to a lesser degree by chromium, titanium, vanadium, or other deoxidizing elements. The degree of deoxidation affects the density of the cast structure and broadly classifies the steel as killed, semikilled, or rimming. This in turn manifests itself in surface characteristics. The manner and extent of deoxidation also controls the amount, type, and distribution of nonmetallic inclusions formed. The equilibrium of manganese, silicon and aluminum with the slags and pouring refractories with which the metal comes in contact is important, especially in regard to inclusions of fire-clay origin. Some surface Seams and hot-working difficulties can be traced to nonmetallic inclusions.

Jan 1, 1941

By R. Dugdale, F. Habashi

Studies on hand-picked samples of chrysocolla from Arizona showed that heating in an inert atmosphere enhances greatly copper extraction by ammoniacal-ammonium carbonate solutions. Heating in hydrogen improves the extraction of copper even further and maximum extraction by ammoniacal-ammonium carbonate and by sodium cyanide solutions is achieved for samples heated at 350°C. Heating in SO2 atmosphere results in the simultaneous formation of CuSO4 and Cu2O; maximum reaction rate is also achieved at 350°C. At temperatures higher than 350°C, CuCO4 starts to decompose. Chrysocolla heated above 600°C either in argon, H2, or SO2, is rendered less amenable to leaching, supposedly due to the formation of insoluble copper silicates.

Jan 1, 1974

By R. W. Raymond

The death of Louis Janin, which took place Mar. 6, 1914, at Santa Barbara, terminated the earthly career of almost the last survivor, and one of the most illustrious members, of that group of American mining engineers and metallurgists who, in the last quarter of the nineteenth century, directed the development of the mineral resources of the Pacific slope. Louis Janin was born in 1836 at New Orleans. His grandfather, an officer in the French army, had emigrated to this country, with his family, at or before the outbreak of the French revolution. His father became an

Jan 1, 1915

By J. E. House, J. L. Drobnick, R. R. Swanson, D. W. Agers

Since the commercial acceptance of the liquid ion exchange process in the mineral processing industry, it has been predicted that eventually the hydrometallurgist would have a wide selection of commercially available chemical reagents to make separations efficiently and economically of virtually all metals in solution under a wide range of conditions. Several years ago, General Mills began a research and development program to determine if it were possible to develop a reagent to extract a specific metallic ion from solution at a cost that would allow large scale commercial application. A giant step toward reaching this objective was announced in late 1963, when development quantities of LIX®-63 reagent, a highly selective reagent for the extraction of copper, were first offered to industry. The properties of this reagent were de- scribed in a previous paper.1

Jan 12, 1965

By Rex B. McLellan, W. A. Oates, William W. Dunn

Vapor transport experiments have been carried out in order to determine the saturation solubility of carbon in cobalt and nickel with respect to graphite over a large temperature range. Some of the uncertainty existing in the thermodynamics of these systems has been removed and accurate estimates of the heat and entropy of solution of carbon in nickel and cobalt have been deduced. The relatitle partial entropies of carbon are considered to be predominantly vibrational in origin. ALTHOUGH the thermodynamic properties of solid solutions of carbon in cobalt and in nickel have been investigated previously, the results of these investigations show a marked lack of agreement amongst themselves. In this investigation simple vapor transport experiments have been undertaken in order to measure the temperature variation of the saturation solubility of carbon in nickel and cobalt with the object of removing to some degree the uncertainties in the thermodynamics of these systems. In the case of the C-Co system, early measurements of the saturation solubility of graphite in Co show results at the same temperature differing by almost an order of magnitude.1-5 Recently Schenck, Frohberg, and Jaspert6 measured the equilibrium between CH4-H2 mixtures and C-Co solid solutions at five temperatures ranging from 850° to 1050°C. Their values of the activity of carbon in the solid solution, deduced from a knowledge of the chemical potential of carbon atoms in the gas, varies linearly with composition at each temperature and the authors concluded that the solutions were Henryan. The saturation solubilities deduced from Schenck, Frohberg, and Jaspert's measurements are in good agreement with the solubility determined at 1000°C by Rao and Nicholson7 and the value at 1000°C deduced from the measurements of smith8 on the equilibrium between CO/CO2 mixtures and C-Co solutions. The object of this investigation was to check the results of Schenck, Frohberg, and Jaspert and also to extend the range of solubility data to higher temperatures. In the case of the C-Ni system, there is fairly good agreement between the values given by schaefer9 for the saturation solubility of carbon C, in nickel, the value given at 1000°C by Rao and Nicholson,7 and that deduced from Smith's8 measurements of the equilibrium between C-Ni solutions and CO/CO2 mixtures at 1000°C. The values of C, deduced from Schenck, Frohberg, and Jaspert's6 measurements of the carbon activity in nickel are also in fairly good agreement. However, there is a large discrepancy between the above set of measurements and those of Lander, Kern, and Beach," who measured the carbon solubility of nickel in equilibrium with graphite by depositing an excess of graphite on the surface of Ni-foils from a gaseous mixture and subsequently diffusing in the carbon. These results are considerably higher than those mentioned above. The determinations6 of carbon activity a, in nickel from the CH4-H2 equilibrium showed that at all the temperatures investigated, the ac-values varied linearly with concentration up to about a, = 0.6 and then began to increase with concentration much more rapidly. On the basis of auxiliary experiments in which C-Ni solutions were equilibrated with graphite, Schenck, Frohberg, and Jaspert concluded that their CH4-H2 solid equilibrations at high values of a, were spurious and a, behaved linearly with composition up to the saturation limit (a, = 1). The short linear extrapolations of Schenck, Frohberg, and Jaspert's a, data yield values of C, in good agreement with those of Lander, Kern, and Beach." The solubility data for nickel discussed here is presented in Fig. 1 in the form of plots of ln[Cc/(l - 2cc)] vs 1/T. The discrepancies mentioned are clearly seen. In this investigation a vapor transport method is used to measure C, over as wide a temperature range

Jan 1, 1969