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By JOHN R. SUMAN

TONIGHT I want to speak of the current problems and the postwar difficulties facing American industry. American industry has done an outstanding job in adjusting its operations to wartime necessity. The national income for 1942 was nearly $120,000,090,000 and of this outlay approximately $55,000,000,000 went for war material. The enormity of the expenditures for war material is indicated by the fact that the expenditures for war purposes alone were greater than the annual gross national income in the period 1931-34. This tremendous production job in turning out a record output of war products was accomplished by industry in spite of a large number of restraining and hampering influences, and I want to mention several of the more important problems.

Jan 1, 1943

By Henry G. Morris

The use of compressed air for the transmission of power has reached so great a development that we find numerous large establishments devoted to the manufacture of machinery for its production and application, and special periodicals published for the dissemination of information on the subject. Moreover, its employment is so general in mining operations that no apology is needed for the presentation to the Institute of such a paper as the present. The admirable articles of Mr. E. A. Rix, published in Conzpressed Air, show a wide range in the mechanical efficiency of air-compressors, varying, under different conditions, from 15 to 60 per cent.; and it is evident that any

Jan 1, 1902

By Walter F. Bradley

CLOSE to 300 members and guests were registered at the Regional Meeting of the Institute in San Francisco. Oct. 3-6, and many other mining men were present at some of the sessions, but failed to register. Headquarters were at the Palace Hotel. Technical papers for the Metals Session were sponsored by the San Francisco Section, whereas the program for the Industrial Minerals Session was arranged by the Southern California Section. Walter W. Bradley, Chairman of the San Francisco Section, opened the General and Metals Session, introducing President Buehler, who gave a hearty welcome to those present. Clyde M. Eye, of the. Benguet Consolidated Mining Co., presented the first paper, entitled "The Economic and Strategic Value of Philippine Metals to the United States." In closing, he urged. that this country retain and control the Philippines because their large

Jan 1, 1935

By S. Terry, W. Callender, R. J. Cornelius

When a dry ball-mill grinding circuit was in- stalled at the pellet plant of Hamersley Iron Pty. Ltd., it was something of a pioneering venture, since this was one of the first instances where such a circuit had been applied to iron ore on a major scale. The Hamersley pellet plant is located in Dampier on the coast of Western Australia. The feed for it consists of -8mm fines produced as a screened product at the Mt. Tom Price mine 186 miles inland from Dampier. It was these fines that encouraged the choice of a dry grinding facility for the plant. At the outset, tests had shown that the fines could not be filtered satisfactorily with a wet grinding system. At the pelletizing plant, the fines are stockpiled, reclaimed, dry ground in ball mills, formed into pellets on balling discs, hardened on an indurating line, and stockpiled for shipment overseas. These operations are shown in Fig. 1.

Jan 7, 1969

By Arthur T. Word

STANDING room only seemed to be the order at the annual session and luncheon of the Eastern magnetite committee. Gatehouse check at the former indicated at least 80, with 33 attending the luncheon - all the crowded facilities could handle. Chairman Crockett opened the meeting by calling upon Meredith E. Johnson, who presented his illustrated paper on "Prospecting for Iron Ore in New Jersey in 1943." This "wartime" brief was discussed by Lucien Eaton, P. W. Henry, and Chairman Crockett. H. E. Hawkes, Jr., of the U. S. Geological Survey, then presented his unscheduled paper on the "Magnetite Deposits of the Jersey Highlands." Discussion was by A. W. Pinger and Chairman Crockett. Fred E. Stiefel then described shaft sinking at the Fisher Hill mine of the Republic Steel Corp., giving a detailed description of how modern

Jan 1, 1944

By Earl Oliver

IN times like these, the A. I. M. E. and similar societies have their greatest usefulness. . . . Individuals and companies acting alone in the development of public opinion are merely voices crying in the wilderness. United and organized they make a great force that can and does influence public action. . . . What part, if any, then, shall the A. I. M. E. take in these great stabilization processes of civilization? Shall it help to give direction and force to scientific knowledge which comes within its field of activity or shall it merely develop more of it? . . . Is it the A. I. M. E.'s function to help bring system, order and direction out of this situation so that the world can again have forward economic movement, or should it rest on its oars until other agenciess develop that public understanding and direction so necessary for economic progress? As we understand the functions of the A. I. M. E. Petro¬leum Division, they are to discover and promote knowl¬edge for the benefit of society on the mining of oil and gas. To the individual member of the Petroleum Division, there are certain advantages of social and professional contacts, but the collective purpose is that described. And the individual is benefited by membership only as the Division measures up to the purposes of its existence. Consequently, the welfare of this Division and that of its members depends on the extent to which it keeps pace with the needs of society on matters relating to the mining of oil and gas.

Jan 1, 1932

By B. C. Allen

Liquid surface tensions of copper and 18 Group IV-A to VIII transition metals (Ti, Zr, Hf, V, Cb, Ta, Mo, W, Re, Ru, Rh, Pd, Os, Ir, Pt, Fe, Ni. Co) have been measured by the static pendant-drop and dynamic drop-weight methods on the same rod sample. The drops were formed by electron-bombardment heating in high vacuum. Application of necessary corrections enabled determination of surface tensions to k2 pct and agreement between methods to * 1 to 4 pct for all the metals studied. Evidence is presented that the liquid surface was well screened by metal vapor, suggesting negligible adsorption of gaseous impurities and that the surface tensions measured are characteristic of the metals involved. Correlations between liquid surface tension and melting point, molar volume, heat of vaporization, and atomic number are presented and discussed. Temperature coefficients of surface tension were calculated using Eötvös' law. SURFACE tension and interface energies of metals are the result of incomplete atomic coordination resulting in a force perpendicular to the boundary, tending to minimize its area. These energies are important in many phases of metallurgy, including microstructure, sintering, joining, electronic emission, and lubrication, which in turn affect many physical and mechanical properties of metals. Liquid surface tension refers to the interface between the liquid and its own vapor or nonreactive atmosphere, and is considered a physical property of the liquid. Since equilibrium shapes can be readily obtained with liquids, the units of surface tension (force per length) and interface energy (energy per area) are interchangeable. Thermo-dynamically, the surface tension ?LV is given by the change in free energy F with surface area A at constant pressure P, temperature T, and composition N: for commercially important refractory metals, vanadium, columbium, tantalum,13,14 molybdenum,14 and tungsten,l5 and none for the rare platinum-group metals and rhenium. Measuring the surface tensions of transition metals is difficult because of their high reactivity and melting points. Of the many techniques available,16-18 the pendant-drop 19-21 and drop-weight methods17,22 are considered superior because they can be modified to eliminate persistent sources of contamination such as supports and capillaries necessary in the popular sessile drop, capillary rise, and maximum-bubble-pressure techniques. The necessary modification is to melt a drop on the tip of a vertical rod, which provides support through a solid of the same composition.13,15 The object of the work was to study the surface-tension behavior of copper and transition metals, having reasonably low vapor pressures. Liquid surface tension of each pure metal was systematically determined by using a combination of the static pendant-drop and dynamic drop-weight methods on the same rod. Liquid drops were formed by electron-bombardment heating in high vacuum. EXPERIMENTAL WORK As indicated in Table I, the metals studied were high purity and generally were obtained in rod form. The exceptions were titanium and zirconium, which were machined from crystal bars, and molybdenum (tot 11, osmium, and ruthenium, which were sintered and arc cast into rods. All the metals were ground or swaged to desired sizes between 1- and 7-mm diam, and centerless ground round and smooth to a finish better than 50 µ in., rms. Each rod was thoroughly cleaned with steel wool, degreased, acid etched, and dried. In a typical run, the rod was vertically clamped in a modified floating-zone electron-bombardment furnace designed after Calverley23 and Carlson.24 The specimen was outgassed and maintained positive at several kilovolts in a dynamic vacuum of 10-5 to 10-7 mm. The bottom end was enclosed by a tantalum pillbox and heated by electrons emitted from a hot concentric tungsten filament mounted on a movable bracket. The bombardment power was slowly raised until melting was observed. Power requirements ranged from 30 w for copper to 1300 w for 4-mm tungsten. The stabilized and out-gassed drop of near-maximum size was photographed at 4. 1X on panchromatic film at desired time inter-

Jan 1, 1963

By GILBERT E. SEIL

GREAT advances in the preparation of ores for reduction to ferro-alloys have been made, although standard methods of reduction have been continued at most plants. Efficiencies, yields per furnace, and energy requirements per ton are generally better than previously attained. The advantages of sizing and conditioning of ore, fluxing stone, and coke have been realized. Conditioning varies from drying the furnace burden to chemical rearrangements to facilitate reduction reactions and sometimes to furnish some of the energy required for the reaction before the burden reaches the furnace. During the war period it is impossible to discuss in detail many of the advances made. They are subjects for postwar papers. However, the new procedures mentioned in the following paragraphs are indicative of the work already done and in progress.

Jan 1, 1944

By Lovell Lawrence

MAGNETITE deposits in the Eastern States have been mined uninterruptedly since pre-Revolutionary War days. The industry, thriving in normal times, was given impetus in all periods of tumult, and continued to advance and expand, until the Lake Superior ores came into production. A period of comparative quiet existed until increased freight rates, together with increased mining costs on Lake Region ores, permitted the magnetites again to compete. This, coupled with World War demands, created unpre¬cedented activity. Producing plants were at their peak, new mines were equipped and put in operation and the industry pushed production beyond the absorption point. Ore stocks were tremendous, internal competition severe, and a great increase in import of European ores brought the industry to a low ebb in 1923.

Jan 1, 1933

By Robert T. DeGavre

The $650 million financing for Into Ltd.'s Soroako nickel project is a story worth telling-not only because the project itself represents a significant achievement but also because there are certain important lessons that can be derived from our experience in financing the project. A critical appraisal of the methods and successes in the financing plan is presented in this article, in light of goals which Inco sought to achieve. A technical assessment of the project is not included, since Inco Ltd. has submitted a series of papers on this subject at the International Laterite Symposium as part of the 108th Annual Meeting of AIME in February 1979. Progress in developing and financing the project is encapsulated in the accompanying project factsheet.

Jan 3, 1979

By Edwin H. Olson, Morton Smutz, Charles J. Baroch

IN 1949 an orebody containing some 10 billion lb of recoverable rare earth metals was discovered in the Mountain Pass district of San Bernardino County, California.1 The following year Molybdenum Corp. of America purchased a number of claims at the deposit and a mill on the property which had been constructed to process the district's gold ores. Average composition of ore from the San Bernardino deposit is less than 0.1 pct ThO2, 25 to 35 pet calcite, 10 pet rare earth oxides, 15 to 20 pet silica, and 30 to 40 pet barite.2 Rare earth content of the ore analyzes 50.7 pet CeO2, 4.2 pet Pr6O11, 11.7 pet Nd2O3, 1.3 pet Sm2O3, and 34.3 pet La2O3, and others.2

Jan 3, 1959

By J. A. Hutcheson

NO one questions that it is technically possible to achieve the controlled release of atomic energy in a form that can be converted into heat or electricity. However, before this is actually an accomplished fact a great amount of work must .be done. This work falls into two general classifications: research and engineering development. At present a research program is under way in this country, co-ordinated and directed by the Atomic Energy Commission, which, as time goes on, will uncover fundamental knowledge of this new science that is essential before industrial applications of atomic energy are practical. Undoubtedly therefore, as the store of available knowledge increases, a time will come when answers to the many questions relating to practicality of atomic energy in industry can be determined with reasonable certainty. That the application of atomic energy in industry will eventually be proved practical is assumed. What then are the engineering problems that must be solved before the first practical electric power generating station can be built?

Jan 1, 1948

By E. W. Murbach

The oxidation of uranium carbide by oxygen at various pressures, and by air, has been investigated at temperatures up to 600°C. Arc-melted and cast uranium carbide displays oxidation behavior that appears to be dependent on its treatment after melting. ccReactive" uranium carbide, which results from exposure of freshly melted material to laboratory air, ignites in oxygen at about 275° to 350°C depending on pressure, and in air at about 350°C. The product of the initial oxidation appears to be UO2+.. Continued heating produces U30,. The initial oxidation rate is poportional, roughly, to the square root of the oxygen pressure. The activation energy determined for the initial oxidation reaction is 7.1 kcal, from 400° to 600°C in 10 mm of oxygen. AN investigation of low-decontamination methods for reprocessing uranium carbide reactor fuels is being carried out at Atomics International. One of the reprocessing cycles includes oxidation of the fuel at relatively low temperature (300° to 500°C) and reaction of the product oxide with carbon at elevated temperatures (above 1500°C) to produce uranium carbide. A number of small-scale experiments have been carried out in which uranium carbide was oxidized in air and oxygen at various pressures to measure reaction rates and to obtain other information concerning the oxidation process. In initial experiments with arc-melted UC, ignition was observed at about 275°C in oxygen or 350°C in air. However, similar experiments by Neymark' at 426°C in air showed no ignition. It was soon determined that the difference in oxidation behavior was due to the treatment of the UC following arc-melting. Neymark's experiments were carried out with freshly melted UC while those reported in the

Jan 1, 1963

By Hermann Schmalzried, Carl Wagner

UPON heating a metal oxide or sulfide in H2, first only oxygen or sulfur is removed from the surface. Thus the metal/nonmetal ratio in the oxide or sulfide increases and the thermodynamic activity of the metal increases accordingly. For the formation of metallic nuclei, a certain super saturation is necessary, i.e., the activity of the metal must become greater than unity. Once nuclei of the metal have been formed, the supersaturation is supposed to decrease. Even under steady-state conditions of a reduction process, however, the activity of the metal inside an oxide or sulfide phase must be greater than unity in order to have a driving force for the individual steps of the reduction process. As an example, consider the reduction of Ag2S with a high mobility of cations and electrons. As shown schematically in Fig. 1, the reduction process involves the following steps:' 1) sulfur removal along the entire Ag2S surface in form of H2S, 2) migration of Ag' ions and electrons from the Ag2S surface to nuclei of metallic silver, 3) transfer of Ag+ ions and electrons from the Ag2S phase to the metal. For a finite rate of step 3, the activity of silver in Ag2S next to the Ag2S-Ag interface must be greater than unity. Moreover, for a finite rate of step 2, the activity of silver at the gas-Ag2S interface must be still somewhat greater. Theoretical considerations lead to the tentative conclusion that at least under steady-state conditions the supersaturation will be rather low.' To test this conclusion, the average activity aAg of silver in a Ag2S tablet about 2 mm thick with a diameter of 5 mm was followed as a function of time by measuring the electromotive force E of the cell Pt I Ag | Agl I Ag2S I Pt where AgI is used as a solid electrolyte in which only Ag+ ions are mobile. The activity aAg is calculated as aAg=exp(-EF/RT) Since the diffusion coefficient for transport of silver in Ag2S is very high (- 3 . l0-2 sq cm per sec),3 the average activity aAg is representative for both the bulk and the surface of the Ag2S tablet. Experiments were conducted at about 400°C. The cell was surrounded by an aluminum block in order to secure a uniform temperature and to eliminate thermoelectric effects. With the help of a potentiometer, first a potential of 0.16 v was applied to the above cell in argon in order to obtain a well defined initial state with a Ag/S ratio close to 2.000.~ Then the cell was disconnected from the potentiometer and a gentle stream of H2 was passed along the Ag2S surface. In view of the removal of sulfur in form of H2S, the electromotive force E decreased within 20 to 30 min to zero corresponding to a Ag/S ratio of 2.003 and became negative, indicating a value of aAg> 1. A representative plot electromotive force E vs time is shown in Fig. 2. The minimum of the electromotive force characteristic of the onset of

Jan 1, 1963

By KING HAMILTON GRAYSON

IRON and steel were the only basic industries in the Soviet Republic in 1928 that lagged behind the pre-war production on a comparative basis. This was due to the almost complete obliteration of all industrial units manufacturing iron and steel products during the Revolution, which resulted in the production of 1921 being only 4 per cent of that of 1913. By the end of 1927 the production of pig iron had reached a point equal to 70.5, per cent of 1913; steel was 84 per cent ; and rolled iron was 78 per cent. According to the. planned program of the Supreme Economic Council, the pre-war level of the iron and steel industry was to have been reached and exceeded during 1929-30. The production of the entire period from 1917 to 1928 in comparison with 1913, is shown in the following table

Jan 1, 1929

By J. W. Evans

ONE possible method for the separation of hafnium from zirconium is by the vapor phase oxidation of the purified mixed chlorides. An important factor for success depends on the difference in free energies of the following reactions: ZrCl(g) + O2 = ZrO2(s) + 2C12 [1] HfCl4(g) + O2 = HfO2(s) + 2C12. [2] Prakash and Sundaram1 have calculated these values from certain data and carried out experimental work with partial success. However, their free energy values for reaction 2 diverge rather widely from other data which are presented here. The possibility of successful separation is briefly considered in the light of these alternative values. Table I shows the free energy values (?F°) for reactions 1 and 2 derived from the recent compilation of data on oxides and chlorides by Glassner.2 The corresponding values of Prakash and Sundaram for the same temperatures are also shown. The alternative values to those of Prakash and Sundaram for reaction 2 are substantially confirmed by the data of Kubaschewski and Evans" and Cough-lin' on heats of formation, entropies, and heats of vaporization. In spite of the considerable uncertainty in the hafnium data it is reasonable to suppose that the oxide-chloride free energy difference for two such chemically similar elements would not be very far apart. These figures indicate clearly that the oxidation of hafnium chloride is appreciable at all temperatures. Nevertheless, there is a significant difference between the values for reactions 1 and 2

Jan 1, 1959

By Charles H. Moore, H. Sigurdson

When lime and magnesia are used as fluxes in the smelting of titaniferous ores fluid, digestible slags low in iron oxide and high in titanium dioxide are produced. The mineral phases present in such slags are (Fe,Mg)O.ZTiOp, CaTiO3, and minor amounts of silicate glass (or its devitrification products). The flux additions are added to the ore in relative amounts to crystallize a ratio of (Fe,Mg)O.2TiO2 to CaTiO, of near the eutectic proportions of 60 pct (Fe,Mg)O.2TiO2 and 40 pct CaTiOl. FeO.TiOz (ilmenite) remains present in the slag until the FeO content is reduced to approximately 8 pct. Optimum slag composition is obtained by reducing the FeO content to between 2 and 6 pct. Continued reduction shifts the (Fe,Mg)O.2TiO2 to oxygen deficient structures classified as MgTi306 and MgTi2O.. Further reduction yields titanium oxycarbides and freezes the melts. The(Fe,Mg)0.2TiO2 structure shows a complete isomorphous replacement of iron by magnesium. It also forms a solid solution compound with as high as 12 mols of TiO2 under reducing conditions without the occurrence of rutile or reduced titanium oxides in the slag.

Jan 1, 1950

By A. W. Schlechten, A. H. Larson

Equilibrium H2S/H2 ratios were determined as functions of temperature (500o to 900°C) and composition in a hydrogen-circulation apparatus. Within the composition range studied there exists a two-phase region of "Zr3S4" and "ZrS2". The upper composition limit of this two-phase region is hounded by a disulfide phase and is practically constant over the temperature range investigated. The lower composition limit of this two-phase region is bounded a "Zr3S4 " phase and varies appreciably with tem- perature. The upper composition limit of the homogeneous region of the disulfide phase is not definitely determined, but it appears to he bounded by the stoichiometric composition of ZrS2. The lower composition limit of the homogeneous region of the Zr3S4 phase could not he determined due to the extremely low values of the equilibrium H2S/H2 ratios. Various thermodynamic quantities are evaluated from the data. PUBLISHED free-energy data for the Zr-S system are practically nonexistent. Strotzer, Biltz, and Meisel1 measured the sulfur pressures for the reaction 2ZrS2(s) + S2(g) = ZrS3(s) in the temperature range 783" to 874°C. The average heat of reaction calculated from the temperature dependence of the sulfur pressure is -47 keal. It should be noted, however, that according to these investigators, the two-phase region as determined by sulfur pressure constancy under isothermal conditions extended from approximately ZrS2, 3 to ZrS2.7. From consideration of X-ray data they concluded that the homogeneous regions of the disulfide and trisulfide phases are ZrS1.8-2.0 and ZrS2.8-3.2, respectively. Hahn and coworkers2 have made a structure study of the zirconium sulfide phases. They summarized the zirconium sulfide phases as follows: the compounds ZrS3 and ZrS2 with narrow homogeneous regions, a "Zr3S4" phase with a homogeneous region roughly within the limits of ZrSl.5 and ZrSo.9, the compounds ZrS and Zr4S3, and a "Zr3S2" phase with a homogeneous region within the limits ZrSo.8 and ZrSo.5. It is noted that the compounds ZrS and Zr4S3 are only formed in the gaseous state through sublimation of a phase which has the approximate composition of the compound. This paper describes the determination of the stability of the zirconium sulfide phases by a hydrogen-reduction method in which hydrogen is circulated over the heated sulfide until equilibrium is attained. The resulting H2S-H2 mixture is then analyzed. Partial molar free energies, enthalpies,

Jan 1, 1964

By Herbert Clark Hoover, Lou Henry Hoover

GEORGIUS AGRICOLA was not only the author of works on Mining and allied subjects, usually asso ciated with his name, but he also interested himself to some extent in political and religious subjects. For convenience in discussion we may, therefore, divide his writings on the broad lines of (1) works on mining, geology, mineralogy, and allied subjects; (2) works on other subjects, medical, religious, critical, political, and historical. In respect especially to the first division, and partially with regard to the others, we find three principal cases : (a) Works which can be authenticated in European libraries today ; (b) references to editions of these in bibliographies, catalogues, etc., which we have been unable to authenticate ; and (c) references to works either unpublished or lost. The following are the short titles of all of the published works which we have been able to find on the subjects allied to mining, arranged according to their present importance :-De Re Metallica, first edition, 1556; De Natura Fossilium, first edition, 15,46 ; De Ortu et Causis Subterraneorum, first edition, 1546; Bermannus, first edition, 1530 ; Rerum Metallicarum Interpretatio, first edition, 1546; De Mensuris et Ponderibus, first edition, 1533; De Precio Metallorum et Monetis, first edition, 1550 ; De Veteribus et Novis Metallis, first edition, 1546; De Natura eorum quae Effluunt ex Terra, first edition, 1546 ; De Animantibus Subterraneis, first edition, 1549. Of the " lost " or unpublished works, on which there is some evidence, the following are the most important:-De Metallicis et Machinis, De Ortu Metallorum Defensio ad Jacobum Scheckium, De Jure et Legibus Metallicis, De Varia Temperie sive Constitutione Aeris, De Terrae Motu, and Commentariorum, Libri VI. The known published works upon other subjects are as follows:-Latin Grammar, first edition, 1520; Two Religious Tracts, first edition, 1522; Galen (Joint Revision of Greek Text), first edition, 1525 ; De Bello adversus Turcam, first edition, 1528 ; De Peste, first edition, 1554. The lost or partially completed works on subjects unrelated to mining, of which some trace has been found, are:-De Medicatis Fontibus, De Putre¬dine solidas Partes, etc., Castigationes in Hippocratem, Typographia Mysnae et Toringiae, De Traditionibus Apostolicis, Oratio de rebus gestis Ernesti et Alberti, Ducum Saxoniae.

Jan 1, 1950

By MERLE HOWARD GUISE

WHEN I was a boy I walked into Fairbanks in 1905. I was but a soft chechako, and arrived with blisters covering my feet, as a result of "mushing" the 400-mile trail on foot. Because of them, the display windows of the trading posts were first to catch my eye-dog and horse collars, harness and sled parts! And because of my enthusiasm for things adventurous, I looked long upon the prospectors' gold pans, shovels, rifles, camp equipment, and what not. Today those windows are filled with motor car accessories, tires and repair parts; yes, even thermos bottles and vacuum cleaners! There were many chance meetings with little parties of prospectors in my youth, and it always set my blood to tingling. Sometimes it was a 70-year-old sun-baked son of the Arizona desert, wrangling his stubborn, faithful jenny away from some outfitting store, at others a shovel-ended poling b0at in northern Canada, \vith the partners and the dogs towing upstream along the bank, or an old sourdough, with tug-rope around neck and hand on the spruce sapling gee-pole, mushing along behind his two or three old, plodding malamutes, dragging a little Yukon sled piled high with rusty sheet-iron stove, pick and shovel, cross-cut saw and axe, rifle, bales of dog salmon, and other paraphernalia. These meetings envisioned the panning of old creek beds and draws in the search for as yet undiscovered pay-channels; they meant the toughest kind of work sinking a hole to bedrock in some far-away valley of promise; they suggested wood fires to thaw the frozen muck and gravel and crude windlass and hand-made tub to hoist the water and the mud; but loudest of all they spoke of Adventure.

Jan 1, 1929