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By Gorr W. W., Wyche E. H, R. Smith

The combination of high strength and corrosion resistance of cold-worked 18 Cr, 8 Ni steel has been advantageously utilized for some time, particularly in aircraft and rail car structures. There are, however, certain limitations on the use of such materials because the high strengths can be obtained only by cold-working, limiting the available products to sheets, strip, wire and tubes. The authors sought to overcome these limitations by resorting to precipitation-hardening, which has been used so successfully in nonferrous metallurgy but only to a limited extent in iron-base alloys. Accomplishment of this objective not only overcame the limitations, but also effected certain improvements in mechanical and other properties. This paper is an account of the development by Carnegie-Illinois Steel Corporation of a precipitation-hardening 18-8 stainless steel (called Stainless W‡ and tentatively identified as type 322). A description is given of its composition and metallurgical characteristics, heat-treatment, physical and mechanical properties and corrosion resistance. Development of the New Steel For a considerable length of time the authors were unable to determine the mechanism of the precipitation-hardening process that had been noted by Ffield18,19 in 18-8 Ti or 18-8 Cb after cold-working and reheating to moderately elevated temperatures. All known variables were exhaustively studied, but with little success. However, results began to indicate that chemical composition was the most important variable, particularly the ratio of austenite-forming to ferrite-forming elements. The investigators then focused their attention upon the composition, and, in particular, upon the element titanium and its mode of alloying in the presence of other elements. A heat was obtained that could not be brought to the softness level of annealed 18-8. The response to cold-straining and aging* was very marked by previous standards, and, more important, cold-straining was found to be entirely unnecessary to produce the precipitation-hardening effect. The chemical composition of this heat was: C, 0.06 per cent; Mn, 0.54; P, 0.016; S, 0.016; Si, 0.58; Ni, 7.28; Cr, 17.60; Ti, 0.90; Al, 0.17. For some time the development work, particularly on composition, was carried

Jan 1, 1947

By Gorr W. W., R. Smith, Wyche E. H

The combination of high strength and corrosion resistance of cold-worked 18 Cr, 8 Ni steel has been advantageously utilized for some time, particularly in aircraft and rail car structures. There are, however, certain limitations on the use of such materials because the high strengths can be obtained only by cold-working, limiting the available products to sheets, strip, wire and tubes. The authors sought to overcome these limitations by resorting to precipitation-hardening, which has been used so successfully in nonferrous metallurgy but only to a limited extent in iron-base alloys. Accomplishment of this objective not only overcame the limitations, but also effected certain improvements in mechanical and other properties. This paper is an account of the development by Carnegie-Illinois Steel Corporation of a precipitation-hardening 18-8 stainless steel (called Stainless W‡ and tentatively identified as type 322). A description is given of its composition and metallurgical characteristics, heat-treatment, physical and mechanical properties and corrosion resistance. Development of the New Steel For a considerable length of time the authors were unable to determine the mechanism of the precipitation-hardening process that had been noted by Ffield18,19 in 18-8 Ti or 18-8 Cb after cold-working and reheating to moderately elevated temperatures. All known variables were exhaustively studied, but with little success. However, results began to indicate that chemical composition was the most important variable, particularly the ratio of austenite-forming to ferrite-forming elements. The investigators then focused their attention upon the composition, and, in particular, upon the element titanium and its mode of alloying in the presence of other elements. A heat was obtained that could not be brought to the softness level of annealed 18-8. The response to cold-straining and aging* was very marked by previous standards, and, more important, cold-straining was found to be entirely unnecessary to produce the precipitation-hardening effect. The chemical composition of this heat was: C, 0.06 per cent; Mn, 0.54; P, 0.016; S, 0.016; Si, 0.58; Ni, 7.28; Cr, 17.60; Ti, 0.90; Al, 0.17. For some time the development work, particularly on composition, was carried

Jan 1, 1947

By F. D. Wright, H. D. Fara

The solution to the plastic and elastic stresses around a circular shaft in a hydrostatic stress field that has appeared in two editions of a widely used book on rock mechanics1 is in error. Although this is a relatively minor matter, the correct solution was not found by a literature survey, so it appears worthwhile to present it. For a homogeneous, isotropic, rigid plastic-elastic body in plane strain which obeys Tresca's yield criterion the following equations must be satisfied:'," In the plastic zone,

Jan 1, 1963

THE 125th meeting of the Institute was held in New York, Feb. 20-23, 1922, inclusive, and was the most successful annual meeting of the Institute ever held; there was a larger registration, there were more sessions of importance, and a greater number of sessions, than in any previous year. The total registration was 1331, comprising 351 New York members, 393 visiting members and 587 guests. At the annual business meeting of the Institute, held on Tuesday, Feb. 21, with President Ludlow presiding, there was a much larger attendance than usual. The report of the tellers was read and the following officers were declared elected: Arthur S. Dwight, Director and President-District 0 J. V. W. Reynders, Director and Vice-president-District 0 A. R. Ledoux, Director and Vice-president-District 0 Charles F. Rand. Director-District 0 George D. Barron, Director-District 0 William H. Bassett, Director-District 1 Thomas B. Stearns, Director-District 8 William Kelly, Director-District 5

Jan 3, 1922

Jan 1, 1970

By R. L. Fullman, J. W. Cahn

A method is derived for obtaining the distribution of sphere diameters and plate thicknesses (or pearlite spacings) from size distribution functions obtained along randomly oriented lines. The method described offers several advantages over existing methods. IT is often of interest to measure not only the average particle size but also the distribution in sizes of particles dispersed in an opaque material, such as an alloy. Particles of a single size will exhibit a range of apparent sizes on the plane of polish. If the sample contains a distribution of particle sizes, the distribution of observed sizes on the plane of polish is related to the distribution of actual particle sizes by an integral equation, For example, a distribution of sphere sizes, N(r),

Jan 1, 1957

By J. F. Butler, H. W. Paxton

The vapor pressures of manganese in equilibrium with several alloys in the iron-manganese-carbon system between 1200° and 1275°K have been measured using the Knudsen effusion technique in conjunction with a vacuum microbalance. The effect of orifice area of the effusion cell upon the measured pressure has been determined. The binary iron-manganese system shows small negative departures from ideality, and the system of mixed carbides, (Fe, Mn)7C3, in equilibrium with graphite behaves ideally. THIS work is a continuation of the investigations in which the Knudsen effusion method has been used to determine thermodynamic activities in systems and at temperatures of interest to metallurgists. In a previous publication,' the free energy of formation of Mn7C3 was determined and some preliminary work on the solution behavior of this carbide with the hypothetical "Fe7C3" was reported. The present work deals with this latter topic and also includes data on the binary ir-on-manganese system. EXPERIMENTAL METHOD The Knudsen effusion method was used to measure the vapor pressure of manganese in both the alloy and carbide sections of this investigation. This dynamic method of vapor pressure measurement presents a problem when studying solid alloy systems in which one of the components has a much larger vapor pressure than the others. Over-all depletion of the alloy in the most volatile component will occur during evaporation so that the pressure of that component will decrease. Even more serious than the over-all concentration change is the surface depletion of volatile component in the alloy brought about by the slow rate of diffusion of this component from the interior to the surface of the solid particle. Since knowledge of this surface composition is necessary in order to relate it to the activity determined through the measurements, changes in surface composition from the analyzed bulk composition are to be avoided in dynamic vapor pressure studies of solid alloys. The system under investigation in this study presents the problem of surface depletion of manganese since its pressure at 1230°K is 105greater than iron and 1020 greater than carbon. Since the existence of a volatile manganese carbide had been ruled out previously,' the high manganese pressure relative to iron and carbon insured that the only species leaving the effusion cell was manganese. Therefore, the effusing species required no analysis so that the manganese pressure was determined directly from the weight loss of the effusion cell. In order to detect small weight losses near the beginning of effusion, a vacuum microbalance was used to weigh the cell continually. These initial weight loss data allowed the rate of manganese effusion to be determined before the surface of the alloy became depleted in manganese. The apparatus used in this investigation is shown in Fig. 1. Temperature was measured using chro-

Jan 1, 1962

By H. B. Charmbury, D. R. Mitchell

Everyone in the coal industry from top management to the preparation engineer is vitally interterested in recovering as much salable coal as possible from the run-of-mine product. Coal losses from a preparation plant occur in the solid refuse material being discharged from the plant and in the bleed-off slurry from the water circuit. The refuse is generally hauled from the plant in solid form by trucks, conveyors, or aerial trams to the refuse or culm banks or it may be crushed and transported by hydraulic methods to refuse ponds or dams. The loss of coal in refuse material and the extent of this problem has been covered in another paver.' The loss of salable coal in the plant bleed-off slurry is one of the water circuit problems in coal preparation plants. Slurries originate at various places in the processing circuits and are usually disposed of by transportation to waste ponds known as slurry ponds. Even though the combustible material discharged as slurry and refuse from the plant is labeled a loss, the loss must only be considered temporary. There is a tendency at the present time to examine refuse and slurry losses and to reprocess these materials to recover valuable coal. Slurries from eight bituminous coal preparation plants in central and western Pennsylvania have been sampled and examined to determine the amount of recoverable coal in each. Examinations of the samples were made to determine the tons per hour of solids and the gallons per minute of water in the slurry; the size, ash, and sulfur analyses of the solids; and the sink-float characteristics of the larger solids. The extreme fines (—325 mesh material) from one of the samples has been examined further to determine the micron size fractions as well as the ash and sulfur content of the micron sizes. Collection of the Samples: Field trips were made to each of the plants where samples were obtained and discussions held with the preparation engineer prior to sampling. The flowsheet of the plant operation was studied and a time-period selected to obtain a representative sample. At least 20 1-gal samples of total plant bleed-off suspensions were collected at each plant in increments over designated periods belived to be typical of the plant flow Three of the samples were obtained from plants in the Pittsburgh area. Each plant supplied information on the capacity, operating time, type of cleaning equipment used, water and material balances, and auxiliary equipment. From the time required to collect given amounts of slurry and from the amount of solids in the slurry, total solids discharges from the plant were calculated and compared with the plant flow. Ash and sulfur analyses of the total solids were also checked, at some plants, with company figures. In all cases where checks could be made there was reasonable agreement between company figures and those reported here. Analysis of the Slurries: Representative fractions of properly agitated samples were examined in the laboratory to determine the specific gravities of the slurries. The solids and water were separated by filtration to check the weight of each so that the percent of solids in the pulp could be determined. From the resulting data, presented in Table I, it may be seen that the percent solids in the slurries ranges from 2.8 to 39.0 and the amount of solids from 2.61 to 45.61 tph. Size Analysis of Solids: Representative fractions of the slurries were permitted to settle and the clear water was removed by siphoning. The solids were then wet-screened at 28, 35, 48, 65, 100, 150, 200 and 325 mesh. Results of the size analyses are presented in Table 11. These results indicate the extreme variation of sizes and in most cases the degree of fineness of the solids. The amount of —325 mesh ranges from 22.5 to 84.5 pct and the amount of+200 mesh from 8.3 to 69.1 pct.

Jan 1, 1961

By K. E. Merklin, F. D. DeVaney

Students of the modern blast furnace seem unanimously agreed that they are observing a major revolution in practice. Rather than changing construction and operation of the furnaces, most of the great advances now under way deal with the raw materials feed. Prepared burdens have gained increasing significance during recent years. Sizing, concentration, and agglomeration have all become bywords to greater production and reduced operating costs. The remarkable results with test furnaces in which self-fluxing sinter makes up part or all of the ore charge foretell even greater improvements. Other investigators have reported many of these advances, and it is enough to predict here that more and more operators will turn to the use of self-fluxing sinter. This change in the operator's requirements comes at a time when one major section of the iron ore regions, the Mesabi, is finding it difficult to maintain, let alone improve, the tonnage and grade of its shipping product. To meet the new demands with respect to quality and structure, the iron ore producers of this area turned first to screening, crushing, and concentrating intermediate ores. More recently, declining higher-grade reserves have led to multimillion-dollar investments in plants to treat the low-grade magnetic taconites.1,2 To yield a suitable concentrate, the Minnesota magnetic taconites must be ground to about 80 pct through 325 mesh, too fine to be charged directly to the blast furnace or to make acceptable feed to the sinter strand. The pelletizing process was developed to meet the structure requirements laid down by the blast furnace operators. Taconite producers are succeeding in their efforts just when the attention of the blast furnace man is being drawn to the great advantages of self-fluxing sinter.3 The taconite operators are ready with an alternative. Why not produce sclf-flus ing pellets? At the Hibbing laboratory of Pickands Mather & Co., where much of the early work was done that led to Erie Mining's 7.5-million ton taconite plant at Hoyt Lakes, Minn., preliminary investigations have been made. Present Taconite Operations: Details of this work will be clarified by a brief review of agglomeration practice in commercial taconite plants. After the taconite has been ground to about 80 pct through 325 mesh to liberate the magnetite grains, the ore is concentrated on magnetic separators, thickened, and filtered to about 10 pct moisture. This structure and moisture fit in closely with the conditions required to produce good balls. It has been found with taconite concentrates that at least 60 pct of the feed to the balling drum must be —325 mesh to obtain good ball compaction within reasonable time. The filter cake moisture usually permits a slight water addition at the balling drum, and further balling control is obtained by adding about 12 Ib of bentonite and 1 1/2 lb of soda ash per dry short ton of concentrate. These additives, and occasionally small quantities of fine coal, are thoroughly mixed with the filter cake ahead of balling. The swelling property of bentonite improves the green and dry strength of the balls so they can be handled without breakage until they are fired. Soda ash is added for pH control to insure maximum performance of the bentonite, and coal is added for more heat in the firing process when required. The balls, normally 3/8 to l-in. diam, are brought to a temperature of 2350" to 2500°F in the indurating furnace. Heat for this process comes from three sources: 1) fuel burned in the combustion chamber, 2) oxidation of the magnetite concentrates to hematite, and 3) coal added to the balls. Pellet strength is developed by grain growth and bridging and, if enough slag-forming constituents are present, by slag bonding. Conversion to hematite is usually close to 100 pct in the fired pellets. Batch Test Procedures: Initial studies of self-fluxing pellets were made by producing balls on a batch basis under carefully controlled laboratory conditions. The l-in. balls, uniform in size, were fired in an oxidizing atmosphere in a standard laboratory muffle furnace. The firing procedure consisted of

Jan 1, 1961

By Lewis Blanchard Brown

It is my purpose in the following paper to describe the south-central part of Siberia, with special reference to its geology and the mineral deposits. This region is known politically as the Achinsk and Marinsk districts of the Tomsk Government. It is situated among the Altai mountains, in. ]at. 50° to 55O n and long. 87O to 93O E., not far from the northern frontier of Mongolia, and is divided as follows: Mining Districts.—(1) The Tomsk mining district, including the political districts of Altai (belonging to the private crown lands of the Russian Emperor) and Marinsk; (2) the AchinskMinusinsk mining district, including the political districts of Achinsk and Minusinsk; and (3) the North Yenisei mining district, situated in the northern part of the Yenisei political district of the Yenisei Government. Fig. 1 is a map of the Tomsk mining provinces, showing the useful mineral-deposits, excepting those of gold, and giving the routes of the railroads and post-roads connecting the various districts. Political Divisions.—The Tomsk Government is sub-divided into seven " oojesdy " or districts, as follows: Barnaul; Biisk; Kuznetsk; Kainsk; Kolyvan; Marinsk; Narim; and the Altai district (private land, as above). The Yenisei Government is sub-divided into five "oojesdy" or districts, as follows : Erasnojarsk ; Kansk; Yenisei; Achinsk; Minusinsk. Concerning the geology of the region, in addition to the record of my own observations, references will be made to the works of earlier writers. These have been consulted for the purpose of comparison, as regards the districts which I have actually traversed, and for the purpose of completing my account of such portions as I have not been able to visit.

Jan 1, 1904

By H. H. Dreissen, F. J. Fontein

The operating principle of the classifying cyclone has been described often but some special aspects of the cyclone receive further clarification here. In addition, several uses of the classifiers are summarized and made clear by means of practical examples. In coal and ore washeries, the washing cyclone is widely used for the separation by specific gravity of sizes up to about 12 mm. This application has lately been extended to the separation by specific gravity of particles up to about 50 mm. This use makes special demands on the construction and wear resistance of the cyclone. The sieve bend, a development of the Dutch State Mines which is less well known than the hydrocy-clone, is dealt with at some length. The sieve bend is an apparatus designed for wet screening. Attention is given to the variables influencing the performance of the sieve bend. Hydrocyclones are now so widely applied that it would be difficult to find an industry not, directly or indirectly, using them or knowing how to use them since publications on this subject abound.1-3,5,9-11,13-15 However, because of the large number of variables influencing the operation of classifying cyclones, it is not entirely possible to calculate the results of this type of cyclone. Therefore, a number of lesser known variables will be discussed here along with some special applications of the classifying cyclone. FACTORS INFLUENCING CYCLONE CLASSIFICATION Shape of Particles: The shape of particles may cause a much coarser classification than the one expected, considering the sieve analysis and the cyclone dimensions chosen. This was clearly shown by feeding a mixture of spheres and disks in water into a cyclone. The spheres were 0.36 mm diam and the disks, 3 mm diam and 0.03 mm thick. These dimensions were chosen in order that the disks and spheres might have the same rates of fall under gravity. Both spheres and disks had a specific gravity of 1.05. The results obtained with these particles in a cyclone are summarized in Table I. Test No. 2 shows that the catch of spheres was

Jan 1, 1963

By Phillip E. Deering, Robert M. Cox

A model pillar study was conducted in which the engineering principles of dimensional analysis were applied to the problem of coal mine pillar design. The paper reviews the theory of similitude as applied to the model pillar study conducted in the investigation. An example solution of a design problem is included to indicate how the results of the study may be used as a first approximation in the design of coal mine pillars. The design of mine pillars for adequate support with minimum loss of valuable raw materials has always presented a problem to the mining engineer. Most often, for lack of a better method, past practice has influenced the design of new mine pillars. This process has always left doubt as to the safety factor of the pillars. The work presented in this paper is an initial attempt toward adapting the engineering principles of dimensional analysis to the problem of pillar design in underground mines. The use of the dimensional analysis technique is advantageous because all the variables associated with the problem are considered, and by systematic analysis the relative influence of each variable is determined. The model material utilized in this study was taken from the Helena seam of the Cahaba coal field located in central Alabama. The research study was sponsored by The Southern Electric Generating Co. as part of an over-all rock mechanics investigation of the Helena seam area. THEORY OF SIMILITUDE Model analysis is used extensively in engineering today, particularly in the solution of design problems that defy the classical methods of analysis. Such problems arise when materials with a nonlinear stress-strain relationship are involved, when geo- metric boundaries are difficult to define in simple form, when strains become large, or when partial failure occurs. All of these difficulties usually exist in pillar design problems. Those principles which underlie proper design and construction of models, and the interpretation of test results, comprise the theory of similitude. That is, the theory of similitude includes a consideration of the conditions under which the behavior of two separate entities or systems will be similar, and the techniques of accurately predicting behavior of one from observation of the other. The theory of similitude may be developed by dimensional analysis. Dimensional analysis, as a powerful analytical tool, is developed from a consideration of the dimensions in which each of the important quantities involved in a phenomenon is expressed. It is based on two axioms: 1) Absolute numerical equality of quantities may exist only when the quantities are similar qualitatively. 2) The ratio of the magnitudes of two like quantities are dependent on the units used in their measurement, provided that the same units are used for evaluating each. Dimensional analysis, developed from these two axioms, differs from other types of analysis in that it is based solely on the relationships that must exist among the pertinent variables because of their dimensions, rather than on the relationship of natural laws. In itself, dimensional analysis ~rovides qualitative, rather than quantitative relationships, but when it is combined with experimental procedures, it may be made to supply quantitative results and accurate prediction equations. APPLICATION OF THEORY The design of an adequate mine pillar requires the determination of a design equation and the selection of a dimensional system with which to work. Since force plays an important part in the design of mine support, the FLT (force, length, time) system has been used. The factors involved in the dimensional analysis of mine pillars and their dimensions are: A = cross-sectional area L Cp = design strength FL- E, = tangent modulus of elasticity FL

Jan 1, 1969

By J. R. Lucas, R. L. Frantz

Mine sealing programs for the alleviation of acid mine drainage were begun by the Federal Government in the '30's. As part of an acid mine research project to The Ohio State University, a field test was undertaken to determine the effectiveness of mine seals for reducing mine acid. Details of the tests made at the McDaniels mine show the feasibility of air-sealing and flooding an acid-producing drift coal mine. Work by the University continues. The Federal Government undertook in the early thirties an extensive mine sealing program for the alleviation of acid mine drainage. In the states of West Virginia, Ohio, and Pennsylvania many general summaries have been made on this program but no critical evaluation with supporting data has been found on the effectiveness of mine seals for reducing mine acid. Because of this it was decided to undertake a field testing program as part of an acid mine research project of the Engineering Experiment Station, The Ohio State University. The objective of this phase of the project was to develop and install a field research laboratory for acid mine drainage studies. Specifications for such a mine laboratory were developed and resulted from the following considerations: 1) Size and preservation—the test mine shou1d be of limited size to permit frequent and detailed examinations; it should be in a reasonably sound condition to permit safe entry. 2) Isolation—the mine should be physically separated from all other mines. 3) Openings—a minimum number would be desirable to reduce the sealing problem. 4) Structure—the mine especially near the openings should be structurally sound. 5) Acid production—the mine should be producing significant quantities of acid. After considerable searching, the McDaniels mine was selected in the Hocking coal field in Vinton County just above Lake Hope State Park in southeastern Ohio. The small drift mine in the middle Kittaning coal consisted of two small rooms with one mine opening about 6 ft above a seasonal stream bed. Before it was finally decided to seal the mine, a short study was made of the acid drainage over several months. Fig. 1 shows a plot of acidity (milligrams per liter), flow (gallons per minute), and acid production (pounds per day) vs time over the sampling period. Because the coal was overlain with a porous sandstone, the mine drainage was consistent the year around even though the mine was

Jan 1, 1961

The regular activities of the Institute are financed mainly by income derived from members' dues, from advertising in MINING AND METALLURGY, and from the sale of publications to the public. In addition, collateral activities and special projects are financed each year by means of income from endowed funds controlled and administered by the Institute. In the aggregate, the principal sums of these endowments amount to more than $530,000. An active effort is being made to increase the endowment funds of the Institute through a standing committee, of which H. T. Hamilton is chairman, and of which the other members are: W. H. Aldridge, George D. Barron, Cleveland E. Dodge, D. C. Jackling, Henry Krumb and J. V. W. Reynders. This committee feels that there exists a tremendous opportunity for the Institute to be of ever-growing service to the public, to the mineral industries, and to the profession. It welcomes suggestions as to names of men of means who are vitally interested in the mineral industries, and to whom the opportunity to make a contribution or bequest might appeal favorably if presented in the proper light by the committee.

Jan 1, 1941

By J. F. Havard

The enterprises based upon the industrial minerals are diversified in geologic habit, mining systems, processing techniques and marketing methods. Nevertheless, in 1972 these enterprises faced many of the same frustrations and hopes and knotty problems and crucial decisions. Volume and profits were generally improved but were uneven in extent and effect. The U.S. cement industry, for example, was unable to meet demand in major markets. It was constricted by a frozen low-level price structure, faced expensive pollution control measures and watched heavy imports penetrating its markets from several European nations, Mexico and Canada.

Jan 1, 1973

By N. A. Gokeen, M. Ohtani

EFFECT of elements on the solubility of carbon in liquid iron is useful in calculating and correlating a number of thermodynamic properties as shown elsewhere in detail.' Kitchener, Bockris, and spratt2, and later Turkdogan and Hancock3 have investigated the effect of sulfur on the solubility of carbon at various temperatures and concentrations. For any chosen sulfur concentration, the solubility of carbon reported by Kitchener et al. is considerably lower than that by Turkdogan and Hancock. It was therefore felt that a reinvestigation of this problem was necessary. EXPERIMENTAL METHOD An alloy of Fe-C-S .was prepared with electrolytic iron and ferrous sulfide melted by induction in a graphite crucible, 4 in. high 1 1/2 in. ID under a CO-atmosphere. The temperature, held at 1500" ± 5°C in all experiments, was measured with a Pt-Pt + 10 pct Rh thermocouple immersed into the melt. In order to assure saturation with carbon, the melt was stirred with a graphite rod. After approximately 1 hr at 1500 °C, a sample was obtained by sucking the melt into a silica tube, 4 mm ID. The sample was then analyzed for carbon and sulfur by usual methods. RESULTS The results are presented in Table I and plotted in Fig. 1 with the individual values of Turkdogan and Hancock.3 Scattering in the data is equivalent to 3 pct or less in carbon analysis. The broken line represents the empirical equation obtained by Kitchener et al. from their data. It is evident that the present data are in good agreement with those of the former investigators but in disagreement with the latter. The cause for this discrepancy cannot be readily offered since the experimental methods in the three investigations were nearly identical. Additional evidence corroborating the author's results may be presented in the following manner. The difference between the solubilities of carbon in the ternary Fe-C-X melt with a small concentration of any element X, and in the binary Fe-C melt is %?C = %CIII-%CII [1] where %?C is the change in solubility, and %CIII and %CII are the solubilities in the ternary and the binary systems respectively. The value of %Cii

Jan 1, 1961

By F. Seitz

STAFF: Editor, Gerhard Derge Carnegie Institute of Technology Schenley Park Pittsburgh 13, Pa. Editorial Assistant, M. A. Redmerski Managing Editor, James J. Burke THE METALLURGICAL SOCIETY: John Chipman, President; W. R. Hibbard, Jr., Post-President; C. C. Long, Vice-President; T. D. Jones, Treasurer; R. W. Shearman, Secretary. PUBLICATIONS COMMITTEE OF THE METALLURGICAL SOCIETY: R. Maddin, Chairman; Dennis Carney, J. C. Fulton, J. H. Hollomon, T. B. King, C. C. Long, W. 0. Philbrook, J. D. Sullivan, David Swan, and F.L. Vogel. Review and selection of manuscripts is under the supervisian of the following Publications Committees: Extractive Metallurgy D ivis ion: T. 0. King, Chairman; S. J. Dick inson, R. P. Hermsdorf, R. Schuhmann, Jr., and H. H. Kel logg. Institute of Metals Division: F. L. Vogel, Choirmon; R. L. Smith, Vice Chairman; R.W. Balluffi, J. H. Bachtold, A Servi, C.D.Graham, Jr., C. G. Goetzel, F. E. Joumot, Jr., G. E. Pellissier, Paul Gordon, Jock Washburn, Harold Margol in, A. U. Seybolt, I. R. Kromer, R. A. Meussner, R. W. Guard, M. Harmon, J. N. Hobstetter, Dean Starr, P. Shewmon, R. Gordon, J. 0. Betterton, and E. Morgan. Iron and Steel Division: W. 0. Philbrook, Chairman; F. C. Langenberg, C. W. Sherman, J. Wagstaff, and E. J. Whittenberger. Published bimonthly by the American lnstitute of Mining, Metallurgical, and Petroleum Engineers, Inc., 29 West 39th Street, New York 18, N. Y. Telephone: PEnnsylvania 6-9220. Subscription $20 per year for non-AIME members in United States and North, South, and Central America; $25, foreign; $5 for AlME members. Single copies, $4.00, single copies foreign, $5.00. The AlME is not responsible for any statement made or opinion expressed in its publications . . . Copyright 1959 by the Americon Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. . . . Registered cable address, AlME New York ... Indexed in Engineering Index, Industrial Arts Index, and Chemical Abstracts . . .Second class postage paid at New York, N. Y. , ond Ann Arbor, Mich. Volume 215, Number 3

Jan 1, 1960

By W. C. Phalen

The production of salt in the United States divides itself at the outset into two distinct classes…

Jan 1, 1915

By . M. Muskat

A THEORETICAL consideration of the mechanics of various water-flooding systems with the viewpoint of comparing their relative merits involves the study of two fundamental properties of such systems. On the one hand, it is important to determine the efficiency of the flood as measured by the percentage of the total area that is swept out by the encroaching water before water actually reaches the output wells. This is really a measure of the regional tendency of the water to "bypass" the oil. On the other hand, the various systems must be compared from the viewpoint of their resistances which determine the rate of fluid production obtainable for given pressures maintained at the water input wells. The first of these questions has been studied and very definite answers have been obtained by means of simple electrolytic models.1 These models showed that, in an ideal system, the percentages of the areas flooded out before water reaches the output wells are about 57 per cent for the direct line-drive flood (the input and output wells being equally spaced and placed in alternate parallel lines), 74 per cent for the regular five-spot network, and 79 per cent for the seven-spot network. With respect to the efficiency of the usual flooding arrangements, they are, therefore, given quite accurately by the above numbers. With regard to the resistances of the flooding networks, electrical conduction models have also been used successfully2 and are well adapted to the problem of determining experimentally the pressure distribution and streamlines, or over-all resistances of specific flooding networks. However, such models do not permit readily a study of the effect of changing dimensions or configuration within a network, since a new model must be made up for each set of dimensions considered.

Jan 1, 1933

By R. D. Pehlke, J. V. Gluck

AS a portion of a general study of liquid-metal thermodynamics, high-temperature galvanic cells were used to study the effect of added dilute solutes on the activity of zinc in dilute solution with molten bismuth in the range 450° to 650°C. 1,2 The cells were of the type The experimental procedures have been described previously.1 In the course of studies conducted in the bismuth-rich corner of the systems Bi-Zn-Au and Bi-Zn-Cu, marked discontinuities were observed in the electromotive force-temperature relations for a number of the experimental compositions. Above the discontinuity temperatures, the relations, which were linear, exhibited slopes similar to the binary alloy of the same mole fraction zinc, as shown in Figs. I and 2. Below the discontinuity temperatures, the slopes were markedly different, but the relations remained linear. In general, as the amount of the third eletnent was increased, the slope of the lower portion of the relations tended to become less positive. The slopes of electromotive force-temperature relations reflect the entropy of mixing of zinc and, therefore, the occurrence of a discontinuity marks the transition between two different equilibrium situations involving the solution of zinc. A number of other investigators3-5 have used such observations to determine liquidus boundaries in binary alloys. Since the upper portions of the ternary electromotive force-temperature relations of this study had the same slopes as the binary alloys, the discontinuities are interpreted as marking the transition between the single-phase liquid region and the underlying two- and three-phase regions. Reference to the Zn-Bi equilibrium diagram6 confirms that the binary alloys were single-phase liquids at the experimental temperatures. Fig. I shows the electromotive force-temperature relations for the alloys containing Bi-Zn-Au and Fig. 2 shows similar relations for the Bi-Zn-Cu alloys. In the lower portion of each figure, the temperature of the discontinuity is plotted vs the mole fraction of the added solute at the various levels of zinc concentra- tion. Cross-plots from these curves at constant temperature permitted the construction of the partial liquidus surface isotherms shown in Figs. 3 and 4.

Jan 1, 1967