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LIST OF THE MEETINGS OF THE INSTITUTE AND THEIR LOCALITIES FROM ITS ORGANIZATION Transactions Number Place Date Vol Page 1 Wilkes-Barre, Pa May, ?71 1 3 2 Bethlehem, Pa August, ?71 1 10 3 Troy, N Y November, ?71 1 13 4 Philadelphia, Pa February, ?72 1 17 5 New York, N Y May, ?72 1 20 6 Pittsburg, Pa October, ?72 1 25 7 Boston, Mass February, ?73 1 28 8 Philadelphia, Pa May, ?73 2 3 9 Easton, Pa October, ?73 2 7 10 New York, N Y February, ?74 211 11 St Louis, Mo May, ?74 3 3 12 Hazleton, Pa October, ?74 3 8 13 New Haven, Conn February, ?75 3 15 14 Dover, N J May, ?75 4 3 15 Cleveland, 0 October, ?75 4 9 16 Washington, D C February, ?76 4 18 17 Philadelphia, Pat June, ?76, 5 3 18 Philadelphia, Pa October, ?76 5 9 19 New York, N Y February, ?77 5 27 20 Wilkes-Barre, Pa May, ?77 6 3 21 Amenia, N Y October, ?77 6 10 22 Philadelphia, Pa. May, ?78 6 18

Jan 1, 1923

By M. B. Bever, A. K. Jena

Equations for the heat effects of additions of mixtures of multicomponent phases to a solution have been derived in terms of the enthalpy interaction coefficients. By these equations and the measured composition dependence of the heat effects on addition of mixtures of Ag-Cd solid solutions and elemental gold to liquid tin-rich solutions, values of the enthalpy in-teraction coefficients in tin-rich solutions at 541°K have been obtained. Analysis of these results in terms of the regular solution theory and the quasichemical theory suggests that near the melting point of the solvent association in the solution becomes important. SEVERAL recent papers have discussed the nature of dilute solutions on the basis of measured enthalpy interaction coefficients. l-3 These coefficients contribute to the understanding of the constitution of solutions and can be used for the evaluation of thermo-dynamic data of multicomponent systems. Their experimental determination, however, is laborious. This communication reports values of the enthalpy interaction coefficients of silver, cadmium, and gold in liquid tin-rich solutions obtained from the measured heat effects of additions of mixtures of Ag-Cd solid solutions and elemental gold to liquid tin-rich solutions. These measurements were made in the course of the determination of the heats of formation of Ag-Cd solid solutions reported in a concurrent publication.4 THE HEAT EFFECT OF AN ADDITION TO A SOLVENT This analysis is concerned with the addition of a mixture of multicomponent phases from the temperature To to a solvent of known composition at temperature T. If Nmixture << Nsolvent, where N designates the gram-atoms involved, the heat effect per g-atom of mixture added can be expressed as (HT - HT )i = difference in heat contents of component element i in the mixture at T and To Q = heat effect on solution of the mixture at temperature T Also1 Q = S Xi [2] where ?Hi ,T,x = relative partial enthalpy per g-atom of i in solution at temperature T and composition of the solution x x = average of the atom fractions of the added material in solution before and after the addition The relative partial enthalpy ?Hi per g-atom of an element i in a dilute solution composed of a solvent 1 and the solutes j = 2, ... m is related to the interaction coefficients by the following equation5 ?Hi - ?Hi-?Hi,x1-1 + S n1ixj+ . . . +S...S...S nrixn2... Xnji...Xnmm+... [3] vhere Xj = atom fraction of solute j in the solution nri = the rth order enthalpy interaction coefficients, which can also be represented by the more general designation5 L(i)n2,n3...nm and nj may have any positive integral value or zero. For identification of various rth order interaction coefficients, nri is written as nn2i2,...nij,...nmm. Eqs. [1], [2], and [3] combine to give the following general equation for the heat effect on addition of a small quantity of a mixture to a large quantity of a dilute solution n = _?ga ?Ha,To + ? Xi(HT - HT o)i a. i + ?xi?Hi,X,i?1 + ??xnjixj + . . . + ???. . .?. . .?xinrix2n2. . . xnji. . . xnmm+ . . . [4] The first term on the right-hand side of this equation is the heat of decomposition at the addition temperature of the phases present in the mixture, the second term is the heat required to raise the temperature of

Jan 1, 1970

By G. R. Wilms

A study has been made of the structural changes in polycrystalline high purity aluminum during the tertiary stage of creep under conditions of constant tensile load. It appears that there is no basic modification in the particular mechanism of deformation that characterized the preceding secondary stage of creep, but that the changes in crystalline structure produced during the tertiary stage are only a consequence and not a cause of the accelerated strain. Intercrystalline fissures were observed on entry into the tertiary stage, and these might supplement the accelerated rate of strain owing to local stress concentrations. There is evidence that the formation of these fissures may be associated with the presence of surface imperfections, and it is suggested that a more generalized treatment of the results may explain certain creep characteristics of commercial alloys. IN previous work&apos;-4 a study was made of the changes produced when specimens of annealed aluminum were deformed at various temperatures and rates of strain, especially under conditions leading to creep under constant tensile load. It was shown that, as the temperature was increased or as the rate of strain was decreased, elements of the substructure produced within the grains became coarser, and with the strain rate constant at a given temperature, their size tended to an equilibrium value. The preliminary process of the breaking down of the grains into a substructure was identified with primary creep.&apos; The subsequent equilibrium, condition was associated with secondary creep. The question then arose whether the tertiary stage corresponded to any further significant change in the substructure. The question is also of interest in view of the opinion, expressed for instance by Andrade,5 that the tertiary stage is merely an accelerated rate of strain due to the reduced area of section of a specimen under continuous tensile load, and the other opinion, as suggested by the observation by Sully, Cale, and Willoughby6 of a tertiary stage in com-pressive loading, that this third stage is a real effect in its own right. The object of this paper is to record some observations on the tertiary stage of high purity aluminum. Experimental Procedure The material was aluminum of 99.98 pct purity as previously used. The specimens had a rectangular section of l/8 x l/2 in., and extensions were measured over a 1 in. gage length. After machining to shape, the specimens were annealed to give a standard grain size of 0.2 mm and then electropolished. The general procedure involved metallographic and X-ray diffraction examination at progressive stages of elongation (marked by arrows on the curves shown in Figs. 1 and 2), the specimen being extended to fracture under constant load at a given temperature. The X-ray tests were made by the back-reflection method from a stationary specimen, using CoK radiation. The longer edge of the micrographs in the paper corresponds to the direction of applied stress. Results The previous work showed that, in the secondary stage of creep in aluminum, three basic types of structure could be developed according to the temperature and rate of strain. These were: 1—slip, which predominated at the lower temperatures and higher rates of strain and produced the finest and least perfect substructure; 2—cell structure, which superseded slip as the temperature was raised and the rate of strain decreased and which was characterized by a coarser and more perfect structure and an absence of slip lines; and 3—a stage termed "boundary microflow," which predominated at still higher temperatures and lower rates of strain when the cell size had increased and become comparable

Jan 1, 1955

By E. S. Machlin

The kinetics of vacuum distillation, vacuum-melt surface reactions, crucible-melt surface reactions and boiling are analytically investigated. No disagreement with experiment is obtained upon applying a rigid flow model to describe the behavior of the melt in the vicinity of reaction surfaces. The theory focuses attention upon measureable parameters rather than upon the adjustable parameter, stagnant layer thickness, associated with other theories. The rigid flow theory is thus capable of quantitative evaluation and experiments to achieve this evaluation are suggested. KINETICS, rather than thermodynamics, often determine the degree of refinement achieved in vacuum melting. There is little understanding, however, of the kinetic principles involved in vacuum refining. This paper represents an attempt to achieve this understanding. There are two reactions which need to be con- sidered. The first is the refining reaction. The second shall be called the polluting reaction. It is the reaction associated with the introduction of components of the crucible into the melt. The mechanisms of both reactions are unknown. Many models can be constructed to describe either the refining or polluting reactions. For example, consider the refining reaction C + Q = CO(g). One model that can be imagined is that the carbon and oxygen combine in the melt to form CO which then diffuses to a melt-

Jan 1, 1961

LIST OF THE MEETINGS OF THE INSTITUTE AND THEIR LOCALITIES FROM ITS ORGANIZATION Transactions Number Place Date Vol Page 1 Wilkes-Barre, Pa May, ?71 1 3 2 Bethlehem, Pa August, ?71 1 10 3 Troy, N Y November, ?71 1 13 4 Philadelphia, Pa February, ?72 1 17 5 New York, N Y May, ?72 1 20 6 Pittsburg, Pa October, ?72 1 25 7 Boston, Mass February, ?73 1 28 8 Philadelphia, Pa May, ?73 2 3 9 Easton, Pa October, ?73 2 7 10 New York, N Y February, ?74 211 11 St Louis, Mo May, ?74 3 3 12 Hazleton, Pa October, ?74 3 8 13 New Haven, Conn February, ?75 3 15 14 Dover, N J May, ?75 4 3 15 Cleveland, 0 October, ?75 4 9 16 Washington, D C February, ?76 4 18 17 Philadelphia, Pat June, ?76, 5 3 18 Philadelphia, Pa October, ?76 5 9 19 New York, N Y February, ?77 5 27 20 Wilkes-Barre, Pa May, ?77 6 3 21 Amenia, N Y October, ?77 6 10 22 Philadelphia, Pa. May, ?78 6 18 23 Chattanooga, Tenn May ?78 7 3

Jan 1, 1923

T.P. 1958 D. H. DAVIS.*-Mr. Carris has ably pre¬sented the problems of coal preparation, particularly those brought about as the result of increased mechanical loading. Many mines are now crushing the run-of¬-mine raw coal through 12 or 15 in. immediately after it is dumped from the mine car and before it is handled by conveyors. At certain mines the removal of large slate mechanically has been solved by the installation of scalping screens consisting of bars or rails set at spacing of 12 to 15 in. on the top deck of the main raw-coal sizing screen. At the plants where these are in use, the plus 12 or I5-in. raw material contains 60 per cent or more free rock or slate, so that it is easier to pick coal than to pick rock. After the screening at 12 or 15 in. is accomplished, the oversize material is diverted to one side of the shaker, where a picker allows the refuse to pass off the shaker into a chute and guides the coal back onto the shaker. After the large rock has been removed, it is then advisable to reduce the size of rock by crushing before putting it onto a conveyor. A great saving in picking labor has been made by the use of such scalping screens, which in addition has maintained the plant capacity when handling a dirtier feed. The great increase in percentage of coal under 1/4 or 3/8 in., coupled with a greatly increased percentage of free impurities in this size, is the most serious problem that has been brought about by mechaniced loading. Many plants that formerly prepared good quality 1/4-in. to o or 3/8-in. to 0 slack by air¬cleaning are faced with installing facilities for wet-cleaning mechanical and heat-drying and water clarification. The change to wet prepa¬ration of fines usually affects the marketing problems for many coal companies. There will also be problems involving wastage of fine solids and stream pollution. Much work will be necessary for improvements in present practice. Pneumatic and electrostatic methods for cleaning fine coal should receive consider¬able attention in an attempt to avoid wet¬cleaning of fines. The preparation supervisor and the plant personnel should not be satisfied merely to run the cleaning-plant machinery and assume that the job will be done for them. Coal is a heterogeneous substance and in many instances is constantly changing. This is more true when full-seam methods are in use. Only persons trained to observe closely and make the necessary changes in plant operation will be able to solve the many problems that will be imposed on the preparation plants. The plants will require skillful and observant operating men. With full-seam mining methods, seams of roof coal will often be mined. Under the former mining systems these strata were not mined and frequently they contain a high per¬centage of bony and banded partings. The mining of this coal will greatly alter the washability and specific gravity characteristics of the feed to the plant. Often the percentage of 1.40 to 1.60 sp. gr. increased from 3.5 to 7.5 per cent, or nearly a 1.0 per cent increase in the ash content of the 1.60 sp. gr. float coal. Thus the cleaning problem is much more difficult, and it is unlikely the same ash content of cleaned coal can be produced as before without a decrease in recovery or the produc¬tion of a "middlings" product. Mr. Carris had this in mind when he said "The quality of the

Jan 1, 1946

Oct. 8-13, 1917 COMMITTEE ON ARRANGEMENTS H. A. BUEHLER, Chairman, W. E. McCOURT, Secretary, C. J. ADAMI, Southeastern, J. A. CASELTON, Entertainment, F. W. DEWOLF, Book, , E. F. GOLTRA, Finance, L. L. HUTCHISON, Tulsa, E. McAULIFFE, Transportation, P. N. MOORS, Reception, MRS. P. N. MOORE, Ladies, J. D. ROBERTSON, Publicity, VICTOR RAKOWSKI, Joplin., H. A. WHEELER, Excursions, A. THACHER.

Jan 7, 1917

A tentative plan for the Colorado Meeting has been formulated as follows: One day will be spent at Denver, one day at Colorado Springs, one day at Cripple Creek, a trip by automobile to the top of Pike&apos;s Peak, one day at Pueblo, one day at Leadville. All the principal mines and mills of the districts mentioned will be visited, including the gold mines in Cripple Creek, the lead, zinc, and steel works. of Pueblo, the production of ferro-molybdenum by electric furnace at Leadville, etc. Special arrangements are being made for the social entertainment of ladies at all points; one evening at Colorado Springs will be devoted to a reception and dance, and the usual dinner will he given on another evening. The following papers have already been accepted for the Colorado Meeting, and some have already been published: Fireproofing Mine Shafts by the Anaconda Copper Mining Co. By E. M. Norris. (March Bulletin.) Air Blasts in the Kolar Gold Field, India. By E. S. Moore. (March Bulletin.) The Use of Coal in Pulverized Form. By H. R. Collins. (April Bulletin.) Coal Mining in Washington. By F. A. Hill. (April Bulletin.) Carbocoal. By C. T. Malcolmson. (May Bulletin.) Gaging and Storage of Oil in the Mid-continent Field. By O. U. Bradley. (March Bulletin.) An Interpretation of the So-called Paraffin Dirt of the Gulf Coast Oil Fields. By A. D. Brokaw. (April Bulletin.) The Theory of Volcanic Origin of Salt Domes. By. E. DeGolyer. (May Bulletin.)

Jan 5, 1918

By W. T. Roberts, N. G. Turner

A study of the fatigue properties of several grades of commercially pure titanium has established that the strain-aging process is of minor importance in the development of a fatigue limit and a relatively high fatigue strength ratio. Metallographic observations and damping measurements at room temperature indicate that striations are able to spread from grain to grain only at stress levels above the fatigue limit. This suggests that the fatigue limit represents the stress above which large-scale dislocation unlocking takes place. Fatigue tests on annealed material at - 60" and - 196" c showed that under conditions when a thermally activated diffusion process would be suppressed the fatigue limit is not eliminated. Prestraining at room temperature did not have a detrimental effect on fatigue strength at room temperature but a decrease was recorded at — 60°C. This is further evidence that initial dislocation locking is a important strengthening mechanism. TITANIUM and titanium alloys have S-N curves with a definite fatigue limit, and a high ratio of fatigue limit to UTS can be attained. Other materials which show similar fatigue characteristics are mild steel and some Al-Mg alloys. The fatigue limit of these materials has been associated with their strain-aging capacity. It is well-known that commercial-purity titanium contains interstitial impurities which can give rise to a sharp yield point, and a small strain-aging effect following static strain has been demonstrated.7 This type of aging reaction is differentiated from the dynamic aging process when aging occurs during plastic deformation, and which is generally observed at elevated temperatures. In a titanium at room temperature, dislocation locking is associated with the interaction of interstitial oxygen, nitrogen, and carbon atoms with dislocations. Ehr-lich has shown that the distortion produced by introduction of these atoms into the hcp lattice has no shear stress component and hence there is no interaction between the stress field and the screw component of a dislocation. Thus the dislocations as a whole are only weakly locked. It is clear that strain-aging effects in hcp a titanium will be much less pronounced than those observed in bcc iron and steel. In recent years, the attribution of the fatigue limit solely to strain aging has been questioned. It has been pointed out that a definite fatigue limit is observed at temperatures as low as -196°C in some titanium alloys,&apos; and strain aging is not expected to be effective at this temperature. The role of initial locking of dislocations in determining fatigue behavior has been examined in low-carbon steel by Oates and Wilson. They showed that under conditions in which the aging potential is low the factors which control the buildup of local stresses and hence affect dislocation unlocking, e.g., grain size, are important. There are indications that other metals can have a definite fatigue limit with no established strain-aging capacity, an example being magnesium12 which has the same crystal structure as a titanium. The spread of plasticity from grain to grain in hexagonal metals may be more difficult than in cubic metals because of the limited number of slip systems in the former, and this may account in part for their fatigue behavior. The present work was undertaken to elucidate the relative importance of crystal structure, strain aging, and initial dislocation locking in determining the properties of commercially pure titanium when subjected to cyclic stressing. 1) EXPERIMENTAL METHODS Three grades of commercial-purity titanium were used and a material of lower interstitial content was prepared by melting high-purity Japanese sponge titanium (referred to as H.P. Ti). The compositions and typical mechanical properties of the materials are shown in Table I. Fatigue tests were made in push-pull (zero mean stress) using an Amsler Vibraphore machine at a frequency of about 160 cps. Two types of fatigue specimen were used—one with a waisted gage length for determination of S-N curves and the other with a parallel gage length for metallographic studies and damping measurements. After careful machining and mechanical polishing, all specimens were electropolished prior to fatigue testing. The electrolyte consisted of 10 parts methyl alcohol, 6 parts 2-butoxyethanol, and 1 part perchloric acid (SG 1.54) and it was maintained at a temperature of -10" to -20°C during polishing. Tests at room temperature were normally carried out with the specimen immersed in a silicone oil bath which could be heated for elevated-temperature tests.

Jan 1, 1969

INTO their great Pacific Northwest counting house went the members of the Industrial Minerals Division recently, to count their blessings amidst the scenic grandeur and mineral wealth of the State of Washington. From their vantage point in Seattle, those who attended the IMD&apos;s fourth Pacific Northwest meeting turned their sights to the South and Southeast, scanned Montana, Idaho, Oregon and Utah, and predicted a very healthy economic future for their region. The praises of Idaho&apos;s booming phosphate industry were sung by Earl W. Murphy, secretary of that State&apos;s Chamber of Commerce. He said the establishment of Fort Hall, on the banks of the Snake River near Pocatello, first turned the eyes of the world toward what is now the center of the greatest known deposits of phosphate rock-the section adjacent to the common corners of Idaho, Wyoming and Utah. With the founding of Fort Hall, Mr. Murphy said, historians will also rank the construction of the first electric furnaces for the production of elemental phosphorous as equally significant in the commercial history of the West. Those furnaces were installed only last year by the Westvaco Chemical Div. of the Food Machinery & Chemical Corp. at Pocatello, at a cost of $8 million.

Jan 7, 1950

By R. S. Shoemaker, F. W. McQuiston

EMPEROR GOLD MINES Vatukoula, Fiji 1974 Operating Data to July 1 ORE DESCRIPTION: Ore bodies occur in basalt and associated ash beds overlain by andesite tuffs and sediments. The basalt in much of the ore mined is weathered with alteration of olivine to serpentine and iron oxides, and augite to chorite. The most important host minerals for gold are the tellurides sylvanite and hessite. Next in importance the sulphide s, pyrite, marcasite and arseno-pyrite. A small amount of free gold also occurs. Chalcopyrite, sphalerite, tetrahedrite, bornite, galena and native tellurium are present in small quantities. TYPE OF MINE: Underground and open pit ORE HAULAGE TO MILL: 3.5 ton bottom dump skips from underground. 7 ton trucks from open pit. CAPACITY IN TONS/24 HRS: 1345 short tons ASSAY HEADS (1973): 0.232 oz Au per ton, 0.357 oz Te per ton PRODUCTS: Gold Bullion (400 oz bars) Metallic Tellurium (1 2 lb bars ) RECOVERIES: AU 86.2% Te 88.0% ORE GRINDABILITY: 9.25 Kwh/T TOTAL POWER: 25.7 Kwh/T WATER: Pumped 112 mile to a 318, 000 gallon head tank. Consumption: 2 140 gal per ton, no reclaimed water used. TAILINGS: Pumped 2 /3 mile through 8" pipe. Uphill sections are steel. Downhill sections are fibro asbestos.

Jan 1, 1975

By Margaret V. Doyle, R. W. Powers

INTERNAL friction measurements, carried out as functions of temperature, have been used extensively to obtain data on the mobility of interstitial impurities in the Group V metals, vanadium, colum-bium, and tantalum. For a given frequency of vibration, the internal friction peaks at a temperature which depends principally on the particular metal and interstitial impurity. Relaxation times and corresponding activation energies are determined from a knowledge of such peak temperatures for various vibration frequencies. These experimentally determined relaxation times are related to the average jump frequencies of the interstitial impurity atoms using the model of Snoek1 and can be related to macroscopic diffusion coefficients as shown by Polder.2 In these Group V elements, the impurity whose diffusion rate has been the hardest to pin down by the internal friction technique has been carbon. The experimental difficulties associated with carbon in these metals were not evident in the earliest investigation carried out by Ke on tantalum.3 The carbon peak was thought to occur near 140°C at 1 cps on the basis of the enhancement of the height of this peak measured on specimens which had been coated with colloidal carbon and heated in vacuo at 1200°C. Presumably on the basis of similar evidence, Wert identified a peak also near 140°C at 1 cps in columbium with the diffusion of carbon in that element." Later, the difficulties of admitting carbon into these metals without simultaneously introducing oxygen were pointed out by Ang and Wert- nd by Marx, Baker, and Sivertsen.6 The latter suggested that the peaks attributed to carbon in tantalum and columbium might arise from the presence of traces of oxygen, adventitiously absorbed during the carburization. Such suspicion was confirmed, at least in tantalum, when it was found possible to prepare C-Ta specimens without contamination by oxygen. Specimens sci prepared, aitnough high in carbon content, gave no evidence of a damping peak near 140°C.7 Recently, the authors were able to Show that carbon diffuses in tantalum at a rate only slightly slower than that for nitrogen.8 At 1 cps, the carbon peak lies at 34g °C, only a few degrees above the nitrogen peak at 341 °C. However, the two could be distinguished by a different stability with respect to aging at 400 °C and by a different dependence of peak height on solute concentration. On the basis of this experience with tantalum, it appeared worthwhile to search also for a carbon peak in columbium in the vicinity of the nitrogen peak." In this report, the location of the carbon peak in columbium is made known and its position relative to the nitrogen peak is compared with the authors&apos; previous findings in tantalum. In addition, a second source of internal friction seen only in specimens of very high purity is discussed. Columbium was obtained from the Fansteel Metallurgical Corp. as either 30 or 40 mil diam stock. The manufacturer gives the following analysis as typical of this material: 99.4 pct minimum Cb, 0.10 pct maximum C, 0.5 pct Ta, 0.04 pct Ti, 0.02 pct maximum Si, and 0.01 pct maximum Fe. Wires 13 in. long were degassed near 2200°C for 4 to 16 hr in an ultimate vacuum better than 2.10" mm Hg in an apparatus described previously.8 This treatment reduced the oxygen and nitrogen damping peaks observed in the as-received material to less than 0.0001 in Q-1 above background. The latter value varied somewhat from specimen to specimen in the range 0.0004 to 0.0008, depending chiefly on the wire diameter and the frequency of vibration. The high temperature evacuation left the specimen in a rather soft condition, the Vhn being reduced to 40 from a value near 121 in the as-received conGi~iur~. The gram size was about the diameter of the specimen. After outgassing, specimens were loaded with carbon by absorption of such hydracarbons as methane or ethylene. Carbon was also added to a few speclrnens by heating them at

Jan 1, 1958

By Robert B. Hoy

If the reader finds that the basic information in a commodity chapter is insufficient, he can consult the appropriate sources in this chapter to find more detailed or more up-to-date information. In these days, technology develops so rapidly that this 5th edition will be somewhat out of date even by the time it is distributed. A comparison of this edition with the 4th edition (1975) of Industrial Minerals and Rocks will clearly demonstate how rapidly the scene changes. One of the best sources of new information, of course, is attendance at technical meetings. For example, the papers presented at the national and sectional meetings of AIME usually discuss new developments in the respective divisions of the society. Frequently this information is available in Preprints. In addition some are printed in Mining Engineering and/or the Transactions of the Society of Mining Engineers of AIME. Furthermore, other professional and trade journals contain articles pertinent to the field. A journal introduced in 1967, Industrial Minerals, published by the Metal Bulletin, Ltd., London, is an excellent source of information. The Mining Journal, Ltd., also in London, publishes a weekly journal, a Mining Magazine (monthly), and a Mining Annual Review. The latter covers the field from three aspects: (1) by commodities, (2) through technical developments, and (3) geographically. The Industrial Minerals Directory 1977, 1st ed., Metal Bulletin Books, Ltd., London, provides addresses of organizations in the field. Other useful magazines and periodicals include Engineering and Mining Journal, Pit and Quarry, Rock Products, and World Mining, all published in the United States. In addition many new books related to industrial minerals have been published since the 4th edition of Industrial Minerals and Rocks. Most of these are included in the bibliography of each chapter in this volume. Another excellent information source is the proceedings of the Forum on Geology of Industrial Minerals. This group, which held its 18th annual meeting in 1982, is sponsored by a state geological survey or another mineral agency on a rotational basis. The proceedings have been published by the various sponsors and are available as indicated in Table 1. Two major sources of basic industrial mineral and rock data in the United States, and also a good source for many foreign countries, are the US Geological Survey and the US Bureau of Mines. The two agencies publish many reports and maps on a variety of geological and mining subjects. In addition, each agency has an indexed list of all their publications with a free service announcing new publications: New Publications of the Geological Survey, US Geological Survey, 329 National Center, Reston, VA 22092 and New Publications-Bureau of Mines, Publications Distribution Branch, US Bureau of Mines, 4800 Forbes Ave., Pittsburgh, PA 15213. The US Bureau of Mines (USBM) publishes annually Minerals Yearbooks which provide statistical data on mineral products including production, consumption, imports and exports, as well as information on new developments. Another very useful USBM series is called Mineral Facts and Problems. Editions were published in 1960, 1965, 1970, and 1975. Four major series of publications by the Bureau are Information Circulars, Reports of Investigations, Mineral Trade Notes, and Minerals and Materials. The last two are particularly good for news of foreign developments. The Bureau of Mines Employee Directory, available at all USBM offices, lists addresses and telephone numbers for all offices as well as same for all commodity and area specialists.

Jan 1, 1983

By L. R. Woodyatt, H. J. Beattie, C. T. Sims

Theories correlating the formation of u and related intermetallic compounds to the electron-per-atom density of binary and ternary alloys have appeared regularly in recent technical literature. These same principles can be modified and applied to complex precipitation-strengthened alloys such as the iron-, cobalt-, and nickel-base superalloys and the stainless steels. Since these complex alloys contain carbides and other phases that normally precipitate before the U-type phases, the nature and amount of the precipitated phases must be calculated first. The following general formula is then applied to the residual matrix composition of the alloy: element. The magnitude of the resulting number is indicative of whether the alloy will form a a -type phase. When these calculations (which are computerized) are systematically applied to alloys of knoun phase analysis, a breakoff in average electron-vacancy number is noted between U-free and U-prone alloys. Alloys with an average electron-vacancy number higher than the breakoff form a-type phases, while those with lower ones do not form these phases. This method could then be used to eliminate from consideration all experimental compositions that would precipitate undesirable phases. It also is useful in evaluating analyzed heats of alloys where minor heat-to-heat variations determine whether the alloy is o-free or o-prone. THE highly significant development of strong, ductile superalloys to provide reliable construction materials in the 1000" to 2500° F temperature range has been due principally to unremitting application of Edisonian techniques and logic by the dedicated physical metallurgists who have shouldered this responsibility. Tools such as the electron microscope, phase analysis, and computers to accomplish regression analyses have been used heavily, but the effort has been essentially practice of an art, rather than a science. The objective of this paper is to describe and illustrate application of some relatively fundamental principles to certain of these alloy systems in an attempt to remove some of the empiricism from the technology. Specifically, the work presented here deals with the use of periodic-group relationships to predict the formation of intermetallic phases which can occur in primarily austenitic (fcc) structures. Calculations that have been developed might be applied in the design of new alloys and the evaluation of known alloys, and thus have the potential of eliminating vast areas of unnecessary alloy preparation and evaluation. ALLOYING CONCEPTS AND STRUCTURAL FEATURES OF SUPERALLOYS Strength is produced in austenitic superalloys by three principle mechanisms: 1) precipitation of y&apos;; 2) formation of carbides; 3) solid-solution hardening by soluble refractory metals. The first mechanism requires the addition of aluminum and titanium, the second requires carbon and carbide-forming elements, while the third calls for the addition of molybdenum and/or tungsten. A considerable concentration of chromium is usually maintained to resist oxidation/corrosion, but it is also an important carbide-forming element. Fig. 1 shows a sketch and electron micrograph of the structure of a typical wrought nickel-base super-

Jan 1, 1967

By Arthur F. Taggart

In 1900, Elmore found that if an acidulated pulp was stirred up with an oil which was relatively insoluble in and lighter than water, and the mixture was allowed to stratify, much of the sulfide would be found hanging to the lower surface of the floating body of oil and could be skimmed off or overflowed with it. The action of the flotation agent here is twofold, first to select the sulfide from the gangue—what today is called collection—and second, to buoy the collected sulfide away from the gangue. The action in collecting is illustrated by Fig. 1: which contrasts the behavior of drops of oil brought, under water, to the surfaces of gangue and sulfide particles, respectively. The oil displaces water from the surface of the sulfide; the water displaces oil from the gangue surface. If, instead of considering the solid particles the fixed parts of the system of oil, water and solids. we consider the oil and water fixed and the solids presented to the surface of contact, the condition will be as shown in Fig. 2; the sulfide tends to be drawn into the interface and the gangue to be excluded. The sulfide particles are held in the oil-water surface by the tension of this surface. The buoyant effect is supplied by the oil droplets in bringing the sulfides to the water surface, but not in holding them there. Gas as Buoyant Medium of Flotation In 1906 Sulman. Picard and Ballot discovered a practical and substantially fool-proof method of doing what Everson, in 1886, and Fro-nlcnt. DeBavay Bessel and Elmore had been doing in the intervening years, viz.: using gas in place of oil as the buoyant medium for flotation, but retaining oil as the agent. To all of these inventors "oil," with no qualification as to its kind and no true understanding of its function, was the important thing. Hut they placed on the oil an additional burden viz.: froth-making, and it soon became apparent that not all oils were suitable for the dual purpose. As a matter of fact, it is probable that each of these inventors knew only one suitable oil at the time he wrote his patent, but used the generic term in the patent with the usual idea

Jan 1, 1928

ZAY JEFFRIES (written discussion*).-I have read with much interest Mr. Ruder&apos;s discussion of Professor Howe&apos;s paper, "The Supposed Reversal of Inheritance of Ferrite Grain Size from that of Austenite." I am yet of the opinion that my first explanation&apos; of Mr. Ruder&apos;s samples is substantially correct. In that explanation I did not intend, however, to convey the impression that "reversed inheritance" was the general rule nor even of common occurrence but rather that." Non-inheritance" was the general rule. Mr. Ruder suggests that a " perfectly formed" grain is an indication of inheritance. The grains in my Fig. 52 are perfectly formed and in fact more nearly equiaxed than those in Mr. Ruder&apos;s Fig: C,3 yet the grains in the former are known not to be inherited but to have been formed by the partitioning of larger austenite grains. On close examination of Mr. Ruder&apos;s Fig. C the very shapes of the grain suggest partitioning. Again, the grain size (25 to 30 grains per square millimeter) is at least 10 or- more likely 20 times smaller than might be expected of the austenite from which these grains were .formed under the given time and temperature conditions. Mr. Ruder&apos;s newer results on electrolytic and Armco iron are most interesting and instructive. His results fit in. nicely with my conclusions 5, 6 and 10.4 His photographs, however, indicate that the thickness of the pieces of sheet metal are such that abnormal grain growth is promoted. He indicates that equilibrium grain size after heating to 950° C., with furnace cooling, is about the same as his Fig. 1, above. I estimate this to be approximately one-half -grain per square millimeter, or 40 times as large as I have obtained with the same material (Armco iron) after heating Y4-in. bars to 1300° C. for 2 hr. and cooling in the furnace. The effect of thickness of sample on grain size is one which needs more attention.

Jan 3, 1918

By K. D. Hester, A. W. Fletcher

A nickel-copper sulphide concentrate was treated in a pilot plant at Warren Spring Laboratory during 1961, by a hydrometallurgical roast-leach-solvent extraction process devised to cleanly separate the metal values and produce acid sulphate liquors containing the metals. It is shown that 86 pct of the nickel and 95 pct of the copper could be leached from the calcine, after a sulphatizing roast on finely ground flotation concentrate. Iron was removed from the leach liquor by limestone neutralization with a small loss of values. Copper and nickel were separated by solvent extraction with naphthenic acid in kerosene after partial neutralization of the iron-free liquors with ammonium hydroxide. Hydrogen sulphide and chlorine were used to remove zinc (and residual copper) and cobalt impurities respectively. The recovery of pure copper and pure nickel, by electrowinning, from the acidic solvent extract strip liquors finally produced, appears technically feasible. An economic analysis of production costs shows that small, geographically isolated, nickel-copper sulphide deposits cannot usually be worked profitably by established processes. The requirements for profitable operation on a comparatively small scale could possibly be met by a flotation-roast-leach process. Two difficulties, obtaining satisfactory extraction of nickel from a sulphide concentrate and separating the copper and nickel in solution, have prevented the previous use of this method. A solution to the first problem, dissolution of the nickel, was described in a recent paper by Thornhill.1 It was shown in this paper that copper and nickel in a flotation concentrate could be oxidized to water soluble sulphates by roasting in a fluidized bed with added salt cake. Workers at the Warren Spring Laboratory have shown that the separation of copper and nickel can be accomplished by solvent extraction using a relatively inexpensive carboxylic acid, naphthenic acid. Moreover, the mineral acid required to strip values from the loaded solvent could be produced, and the metals recovered, by electrowinning; thus the latter section of the process was regenerative. The removal of iron from the leach liquor and the elimination of impurities such as zinc and cobalt before nickel electrowinning would be necessary to complete the flowsheet. The process under investigation could therefore be summarized (Fig. 1) as follows: 1) Flotation to produce a bulk sulphide concentrate. 2) Fluidized bed roasting to sulphate the nickel and copper minerals. 3) Leaching of roaster calcine to extract soluble nickel and copper. 4) Precipitation of iron from the separated leach liquor by air oxidation after the adjustment of pH and temperature. 5) Recovery of copper from the iron-free Liquor by pH adjustment and liquid-liquid extraction. 6) Purification of the copper raffinate by removing zinc and residual copper as insoluble sulphides and cobalt as cobaltic hydroxide. 7) Recovery of nickel from the purified liquor by pH adjustment and liquid-liquid extraction. Laboratory and pilot plant studies detailed below, were carried out at the Warren Spring Laboratory, to test the feasibility of each one of the unit processes and to obtain preliminary plant design data. FLOTATION The ore was an altered basic rock containing concentrations of magmatic sulphides.

Jan 1, 1964

Jan 1, 1906

By James T. B. Ives

The map exhibited* as an example of my method of construct ing geological strata-maps is essentially an educational appliance. The method, however, is available for the production of maps of comparatively small areas, which, I am confident, will be found of great practical value to mining engineers. Before stating how the method may be so applied I will briefly describe the map exhibited, as the easiest way of making my meaning clear. Almost any region might be taken. This map represents the eastern half of the United States; and the geology is that of the map issued by the Geological Survey, and revised and extended subsequently by Professor Hitchcock for your Institute. I use ten cards, of the colors used in the geological map, each having the geog raphy of the area printed upon it; and I superimpose these in the order in which the colors occur in the index to the map. I next cut away a portion of each card, excepting the lowest, leaving only so much of each as represents the exposure of the formation of that color plus all those which overlie it. When that is done, the whole, looked at from a distance, appears to be an ordinary geological map. Looked at more closely, however, the formations are seen to overlie one another, as in nature. The cards are covered with glass in a frame, which, hinged at the bottom edge, can be let down. The cards are then found to be all hinged in the same manner, and they, too, may be lowered, one after the-other. I am told by teachers of geology of great experience and the highest reputation that by this appliance they will be assisted in im parting to students the first facts and principles of geological sci ence. Having let down the whole series of cards, until that repre senting the Archaean is seen underlying all the rest, the teacher will gradually rebuild it. The Cambrian will thus be laid down upon the Archaean before the eyes of the class, the Silurian upon that,

Jan 1, 1888

The co-operation of the members of the Institute is earnestly sought by the Committee on Nominations, recently appointed by the Board of . Directors, in its work of formulating a ticket for officers and places falling vacant in the Board of Directors in February, 1916. The Committee must present the official ticket of nominations to the Board of Directors at its October meeting. Members are, therefore, urged to send promptly their nominations for officers and Directors in order that the Committee may have an opportunity to give them full consideration. The officers to be elected at the annual meeting in February, 1916, are: One officer, known as Director and President. Two officers, known as Director and Vice-President. Five officers, known as Director; The attention of members is called to Articles V and VII of the Constitution, and to By-Law XIII, which reads as follows: "The geographical districts to be considered by the Committee on Nominations shall he as follows, until otherwise ordered by the Board. District No. 1. New England, New York, and New Jersey, excepting New York City and district., which is provided for in the Constitution. (N. B.-New York City and district is designated District 0.) District No. 2. Pennsylvania. District No. 3. Ohio, Indiana, Illinois, Iowa, and Missouri. District No. 4. Minnesota, Wisconsin, and Michigan. District No. 5. Montana, North and South Dakota, Wyoming, Nebraska, Kansas, Washington, Oregon, Idaho, and Alaska. District No. 6. California and Nevada. District No. 7. Utah, Colorado, Arizona, and New Mexico. District No. 8. Louisiana and Texas. District No. 9. Other Southern States and District of Columbia. District No. 10. Mexico. District No. 11. Canada."

Jan 7, 1915