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INSTITUTE MEDALS AND PRIZES ASIDE from the John Fritz Medal, in which the Institute participates through its representation on the John Fritz Medal Board, the Institute itself has five major awards to make annually for excellence in technical papers, as follows The Robert W Hunt Medal, The Hadfield Prize, The J E Johnson Jr , Award, The Lewisohn Platinum Prize to senior members, and the President's Prize to junior members ROBERT W HUNT MEDAL The partners of Robert W Hunt established a fund which was presented to the Institute at a fitting ceremony on May 27, 1920, to establish an annual medal and a sum of money to be awarded under the following rules, 1 The award shall consist of two prizes, first of a gold medal, second of a sum of money, a certificate to accompany each prize The money prize shall not be awarded to a member over 40 years of age, but under unusual circumstances, both prizes may be allotted to one person provided that he is not over 40 years of age In general it will be understood that the Committee shall award the money prize to, the younger men, rather than the medal 2 The awards shall be made not oftener than once a year to that person or persons contributing to the Institute the best original paper or papers on iron and steel The scope of the term "iron and steel" shall be determined by the sub-committee consider¬ing the awards In general, papers dealing with the practical side of the subject have preference over those dealing with the theoretical side in recognition of the fact that Captain Hunt's main contributions to the industry have been in the improve¬ment of production and quality of material 3 A sub-committee of three to five, including the Chairman of the Iron and Steel Committee, shall be appointed by the Iron and Steel Committee annually to adjudge the award subject to approval 4 The awarding committee shall submit its report to the Iron and Steel Committee at its October Meeting, and the award be certified to the Secretary of the Institute in time to permit the presentation to be made at the Annual Meeting of the Institute 5 The recipient of the award shall be designated "The Hunt Medallist "

Jan 1, 1923

By Carmine D. &apos, Lemuel Tarshis, Joel Hirschhorn, Antonio

Vapor-deposited nickel films in the thickness range 700 to 4360A were tested in uniaxial tension utilizing a microtester designed specifically for this study. Contrary to the findings of some investigators, a definite thickness-strength relationship was observed below 3000 A with a four-to sevenfold increase in strength over that of bulk nickel. The films were characterized by high elastic strains and little plasticity. On the basis of these and other reported data, it is suggested that the high strength level in metal films is related to the manner in which they are produced. Vapor deposition, owing to its severe quenching effect. is believed to promote the formation of point defects which inhibit dislocation movement. IN recent years it has been reported that metals, when in the form of thin films, exhibit extraordinarily high strengths. The data published to date have been primarily concerned with silver and gold because of the ease with which these metals can be vapor-deposited and their high resistance to surface oxidation. Previous investigations into the mechanical strength of thin films has uncovered an apparent dichotomy of view on film behavior. Beams and his co-workers have reported a definite dependence of strength on film thickness. Other workers,"-'6 however, in separate studies on the strength of poly crystalline and single-crystal films have found no such thickness-strength relationship. The study of thin-film strength is extremely difficult because of the many variables associated with film preparation, handling, and testing. Moreover, the manner of test employed by different investigators has varied quite radically, ranging from simple uniaxial-tension to biaxial-bulge testing. The work reported herein was conducted in order to determine the mechanical behavior of a structural metal when in the form of a vacuum-deposited thin film and to gain some insight into the reasons for the high strengths exhibited by metals having such a con- figuration. In this study a method of test was chosen which would yield results which are easily interpreted and lend themselves to comparison with properties of the same material in bulk form. Moreover, specimen-preparation parameters and film-handling techniques are set forth so that other investigators can properly compare their findings with ours. EXPERIMENTAL PROCEDURES A) Film Preparation. Vacuum deposition was performed in an 18 by 30 in. bell jar using a standard New York Air Brake Co. vacuum station with a 6-in. oil-diffusion pump. Before evaporation the system was pumped to a pressure of less than 2 x 10"5 torr. A shield was employed to protect the substrates from the emission of contaminants during the critical melting and outgassing of the evaporant. The source consisted of from one to six filaments (0.020 in. diam). The length of each filament was about 5 in. and was placed 6 to 8 1/2 in. from the substrate in such a manner that the substrate face was at 90 deg incidence with respect to the evaporant beam. The temperature of the source was 2000"~ during evaporation. The films were deposited onto a substrate arrangement which was composed of four basic components, that is: 1) a 3 by 1 in. glass slide; 2) a 22-mm sq micro cover glass on 1); 3) a 22 by 50 mm micro cover glass coated with collodion on 1); and 4) a stainless-steel sheet mask containing twelve rectangular openings of 1-mm and 2-mm widths and lengths of 5 mm laid over 3). Thus, test specimens of 1-mm and 2-mm widths are deposited onto a collodion substrate which precludes epitaxial effects in the specirnens. 17-le The rectangular cover glass and square cover glass were positioned in such a manner that a strip of film would be evaporated along the length and across the width of the large glass slide. This boundary of evaporated film was used to determine the film thickness by multiple-beam interferometry. The square cover glass was used for X-ray and chemical analyses. Thickness of the deposits was varied by changing the number of filaments used (one to six). The duration of evaporation was 30 sec for each filamgnt which resulted in a deposition rate of 8 to 20A per sec. Evaporations were all performed at room temperature; however, radiant heat from the source raised the substrate temperature to 40" to 60°C. All substrates were cleaned by ultrasonic agitation in a solution of spectranalyzed isopropyl alcohol. Collodion was deposited on the micro cover glass by immersion in solution of collodion in amyl acetate. B) Thickness Control and Measurement. Film

Jan 1, 1963

By S. E. Bretherton

During the year 1878-79, Anton Eilers, who was then interested in the lead smelting and refining business near Salt Lake City, Utah, made a somewhat radical departure from the regular practice at that time, which was to use but little lime in the slag, with a high percentage of iron. Lime was not only a cheaper flux than iron, but it enabled the metallurgist to make a more siliceous slag, an economical advantage in smelting where the smelting companies had to purchase either iron or lime to neutraiize the excess silica, and penalize the ore shippers accordingly. The larger amount of both lime and silica in the slag also made it of lighter specific gravity, and a better separation of the metals and mattes was secured. This change in the formation of slags for lead smelting was brought about by Anton Eilers, prior to the Leadville mining excitement of 1879.. We must also give Mr. Eilers credit for the general introduction of the hollow water-cooled cast-iron jacket for the blast furnace. Again referring to the use of more lime and less iron in the formation of slags, there is no doubt but that it prevents the formation of a great many so-called "sows" in the lead crucible, such as were made in the early history of lead smelting in the Rocky Mountains; these sows consisted of lead, iron, arsenic, sulphur, copper, and other metals, including gold and silver, mixed with unconsumed fuel, and often, after vain attempts to cut them up or melt them to a suitable size for handling, were buried in the slag dumps to get them out of sight. Another advantage derived from the adoption of high-lime slags when smelting ore containing arsenic is the production of less speiss (a byproduct heavier than matte, resulting from careless operation of the furnace, in the lead being driven out of the crucible and sows built up). This speiss, while usually not as rich in precious metals as matte made at the same time, is too valuable to be thrown away; but it is difficult to treat, and it was thrown away or piled on the slag dumps in the pioneer days of lead smelting in this country. About the time of the introduction of the lower iron and higher lime slags in lead smelting, sulphide ores were encountered in Utah and Colo-

Jan 1, 1916

By Carl F. Dietz

(New York Meeting, February, 1912.) THE problem of drying ores is one that most mill-engineers are sooner or later called upon to meet, and it may be timely to point out sortie of the difficulties resulting from such operations from purely a metallurgical and economic stand-point. We mean, in the following pages, to discuss primarily the effect of such operations on. the ore itself, without particular reference to the mechanical or cost features of the subject; That an appreciable tonnage of the ore fed to the usual form of drier, either rotary or stack, is lost, is fairly well appreciated, but we believe that only a few mill-managers know just. what their drier-losses amount to, and we have found that in most cases they console themselves with the fact that the drier-smoke is not very much discolored, and it is generally believed that the draft is not sufficient to carry away more than a. negligible percentage of the values. The drying of ores is becoming an important factor. since the more general application of magnetic, static, and dry-table treatment. Its importance in the field of metallurgical operations warrants a close examination into its effects. This subject has been repeatedly brought hone to us, and while the drier-losses, in every case examined, have considerably exceeded even the most generous estimate, an attempt at a recovery of these values is rarely made. We have found that the losses resulting from drying-operations can be effectively recovered, at a low cost, and believe that the publication of the results of a number of investigations along these lines will be of interest and benefit to the profession at large. To dry an ore quickly and effectively, it must be brought into actual contact with hot gases or air. The rapid drying is effected by the fact that the hotter the gas the hungrier it is

Jul 1, 1912

By R. M. Brick, J. T. Richards

Tests have been conducted to determine the mechanical properties of several beryllium copper alloys down to liquid air temperatures. The materials investigated include beryllium copper, beryl-lium-cobalt-copper, and beryllium-zinc-copper in the wrought and cast conditions. As a means of evaluation, the influence of cold work and age hardening treatment upon subzero behavior has been observed. The effects of temperature upon both elastic and plastic deformation are also considered. THE low temperature mechanical properties of beryllium copper are of current interest in view of the increasing number of subzero applications. At extremely low temperatures, beryllium copper components are employed in temperature control and gas liquefaction equipment. At more moderate temperatures, such as those encountered in arctic regions, these alloys find use in a wide range of civilian and military applications. Although several previous subzero investigations have included beryllium copper,'-' none have been complete with respect to test temperatures or materials employed. As indicated in Table I, the alloy: used by Colbeck and MacGillivray,1 Walle,2 and Kostenets' were nonstandard and were not representative of present commercial practice. In addition, Kostenets4 did not test age hardened specimens, while the temperature in the other investigations", "-' were not carried below —100°F. These tests, however, indicate that beryllium copper offers interesting possibilities in subzero atmospheres, since the increase in strength with decreasing temperature is not accompanied by a reduction in ductility or impact resistance. As a means of checking and extending this earlier work at subzero temperatures, an investigation was undertaken at the University of Pennsylvania. In addition to testing the standard 2 pct beryllium copper, other alloys were also considered in wrought and cast forms. Charpy impact and tension tests were included with particular emphasis on the elastic characteristics, since beryllium copper is frequently selected for its spring qualities. Nominal test temperatures were +80°, —75", —200°, and —300°F. Test Materials Wrought beryllium copper, beryllium-cobalt-copper, and beryllium-zinc-copper specimens were machined from 0.560 in. diameter rod. These alloys were tested in the solution treated, cold drawn, or age hardened conditions. In the case of solution treated beryllium copper, some specimens were aged (3 hr at 600°F) for maximum hardness and others were overaged (1 1/2 hr at 750°F) to determine the effect of heat treatment. The compositions and average room temperature properties of these wrought alloys are presented in Table 11. The casting alloy versions of beryllium copper and beryllium-cobalt-copper were prepared as sand-cast cylinders, roughly 3/4 in. diameter x 6 in. long. Test specimens were machined from these cylinders. Conditions tested included as cast as well as solution treated and age hardened. Table 111 lists compositional and room temperature property data for the cast alloys. Test Methods Tension tests were conducted on specimens having a 0.25 in. diameter reduced section over a 1 in. gage length. To insure axiality, specimens were loaded by means of hardened chains. The yield strength at 0.2 pct offset was obtained from autographically recorded stress-strain curves resulting from a spe-

Jan 1, 1955

By H. P. Greenwald

THE rapidly increasing use in coal mines of portable auxiliary fans, which are generally "blowers" employed in connection with canvas tubing, raises questions concerning the hazards of such equipment, especially where the practices are opposed to established methods of ventilating face workings. Half a dozen or more coal-mine explosions and some fires have been attributed to the use of auxiliary fans; moreover, competent mining engineers have found many dangerous installations and methods of use-for example, intermittent running of the fans in gassy mines with consequent accumulations of firedamp at the faces. These facts have led the U. S. Bureau of Mines to issue this recommendation: "In the interest of safety, the Bureau of Mines, Department of Commerce, recommends that auxiliary fans or blowers should not be used in coal mines as a substitute for methods of regular and continuous coursing of the air to every face in the mine." The comparatively recent introduction of new types of mining machines, mechanical loaders, face conveyors, and slabbing machines has encouraged the trial of new systems of face mining, all of which have for their object the rapid advance of the faces. Although the latter has certain economic advantages, in gassy mines the rate at which gas is given off is generally found to increase in proportion to the speed of advance into new territory, which in turn increases the difficulties of efficient ventilation of the face workings. Some of the systems of advance mining being tried in connection with new mechanizing methods practically compel the use of blower fans and tubing, as single narrow places are now driven, 300 ft. or more without crosscuts. In some instances a series of parallel headings are driven without crosscuts pre-

Jan 1, 1928

By S. Feuerstein, L. Rice

The effect of low pressures on the flow and fracture behavior of molybdenum is described. For poly crystalline samples, room-temperature tensile tests indicate greater ductility under 10 Torr than under intermediate pressures up to and including atmospheric pressure (760 Torr). In addition, tests conducted at 760 Torr under atmospheres of air, dry nitrogen, and purified argon exhibited no apparent difference in mechanical properties. Critical tests involving baking in situ as well as those involving single-crystal deformation further imply that the ductility effect is a pressure-dependent phenomenon related only to the fracture process. This dependency is discussed in terms of adsorption and diffusion contributions. THE effect of very low pressures on material properties has heretofore been presumed to be important only for substances possessing relatively high vapor pressures at ambient temperatures. Research has therefore been concentrated primarily on organic solids and liquids, and in some instances on metals such as zinc and cadmium. Most vacuum-effect studies' on the mechanical behavior of metals have been performed under conditions of either cyclic loading or creep rupture at elevated temperatures, i.e., over extended time periods. These studies were not restricted to high vapor pressure materials but also encompassed such metals as gold, copper, and nickel. Very little concern, however, was placed upon the importance of a vacuum environment on the mechanical behavior of metals subjected to a simple unidirectional deformation at ambient temperatures. A tension test is generally of short duration as compared to a creep test, and at room temperature vacuum effects if any would be expected to be surface-limited. In early 1963, Kramer and podlaseck2 reported a change in the bulk flow behavior of aluminum single crystals during room-temperature tension tests. The deformations were performed under pressure conditions of 760 to 3.4 X 10-8 Torr and indicated for the first time a vacuum surface effect contributing to the bulk tensile behavior of metal specimens. As a consequence, an experimental program was initiated in this Laboratory to study the effects of ultrahigh-vacuum conditions on the mechanical behavior of metals. The results of a preliminary study on poly-crystalline molybdenum3 revealed, unlike Kramer's observations of changes in the stress-strain behavior, only an increased ductility under ultrahigh vacuum. Flow behaviors were nearly identical for all tests re- gardless of pressure. This paper presents comprehensive results obtained in this area of research. 1) EXPERIMENTAL PROCEDURE Three material categories were used in this study: sintered and are-cast polycrystalline molybdenum of nominal purity 99.93+ pct and single-pass electron-beam zone-refined molybdenum single crystals having a nominal purity level of 99.99+ pct. The interstitial levels (weight percent) as determined by the Materials Testing Laboratories, Division of Magnaflux Corp., were as follows: sintered molybdenum (C— 0.005, H—0.0004, O—0.015, N—0.008); and arc-cast molybdenum (C-0.0038, H-0.0003, O-0.015, N-0.023). Single-crystal molybdenum obtained from Materials Research Corp. had a typical interstitial analysis of C-0.0015, H-0.00007, O—0.00045, and N-0.0001. Tensile specimens having a 5 mm diam by 50.8 mm length were prepared from these materials. An average grain diameter of 0.059 mm was obtained for the sintered specimens following a 4-hr, 1600°C heat treatment. Grain sizes from 0.019 to 0.149 mm were obtained in the arc-cast specimens following heat treatments from 1100° to 1600°C for 1 hr. This series of specimens was used exclusively for the grain-size effect studies. All samples were electrolytically polished in 97 pct sulfuric acid solution prior to testing. Experiments were performed at room temperature in an ion-pumped ultrahigh-vacuum system positioned in an Instron tensile machine, Fig. 1. A constant strain rate of 4.2 x 10-4 sec-1 as derived from crosshead displacement was assumed for the deformations. Starting vacuums ranged from 2 to 0.5 X 10-10 Torr. These pressure measurements were made using corrected values4 of an NRC Redhead gage. Comparative readings were also made against a G.E. triggered dis-

Jan 1, 1967

By J. C. Williams, M. J. Blackburn

Several of the decomposition processes that can occur in supersaturated phases in a Ti:11.6 wt pct Mo and a Ti:20 wt pct V alloy have been studied by transmission electron microscopy. The deformation induced "marternsitic phase" in the Ti:Mo alloy has been found to have a bcc or bct structure rather than the previously reported hexagonal structure. The morphology of&apos; the transformed region is a rather complex asserrlblage of twins, twinning occurring in one or more systems; this internal twinning has been found to occur on (112). The w phase is formed in both alloys on aging and is present in the Ti:Mo alloy after quenching. The structure of this phase has been confirmed as hexagonal in both systems, however, differences in morphology and stability are found between the two alloys. Thus in the Ti-Mo alloy the w phase has an ellipsoidal morphology with the major axis lying parallel to <111>ß or [0001]w while in the Ti-V alloy the phase forms as cubes, the cube faces lying parallel to {100}ß or {2021}w Some observations on the particle sizes, volume fraction, and composition of the w phase in the Ti-Mo alloy are listed. The mode of formation of The a phase from the (ß + w) structures is also different in the two alloys. In the Ti-Mo alloy the a phase is formed by either a cellular reaction or by the growth of isolated needles, whereas in the Ti-V alloy the a phase is nucleated at an w:ß interface and grow to consume the w phase. Some of the difjerences in behavior of the w phase are attributed to the mismatch between it and the solute enriched ß matrix in which it forms. MaNY transition elements tend to stabilize the bcc or ß-phase when added to titanium. In general two types of phase diagrams are produced, either a ß-stabilized (ß-isomorphous) system, e.g., Ti:Mo, -Ti:V, Ti:Nb, or a ß-eutectoid system, e.g., Ti:Cr, Ti:Fe, Ti:Mn. In previous papers&apos;-4 the phase transformations in the a-phase and (a + ß)-phase alloys have been described and this work has been extended to ß-stabilized systems. Specifically, transformations in the alloys Ti:20 wt pct V and Ti:11.6 wt pct Mo have been studied; in both of these alloys the ß phase is retained at room temperature when quenched from the ß-phase field. A number of phase transformations can occur in such metastable ß phases and the two alloys were chosen to include most of the transformations reported for ß-stabilized systems. We list these possible phase transformations below. Ti:11.6 Mo quenched from >780°C to retain the ß phase: a) The w phase can form on quenching.5 b) Martensite can be produced by subzero cooling or deformation. Two martensite habit planes have been reported in Ti:Mo alloys; (334)ß and (344)ß=6 c) On aging at temperatures <-550° C the w phase is formed before the a-phase.5,7 d) On aging at temperatures >550°C the a phase is formed.7 e) The martensite can be tempered. It has been reported that the a phase rather than the ß phase is precipitated during tempering.&apos; Ti:20V quenched from >660°C to retain the ß phase:9 a) At aging temperatures <260°C separation into two bcc phases occurs. b) The w-phase is produced prior to the a phase on aging at temperatures <-400°C. c) At temperatures 2400°C the a phase is formed directly. T-T-T diagrams describing the temperature and time regimes for the formation of these phases have been published7,9 for a Ti:12 pct Mo and a Ti:20 pct V alloy. We have attempted to investigate these transformations using transmission electron microscopy, however thin foils undergo a spontaneous transformation in all conditions except the equilibrium (a + ß) structure. This transformation has been reported previ0usly10,11 and we will comment on its morphology and nature in the various sections of experimental results. EXPERIMENTAL The compositions in wt pct of the two alloys investigated were: Ti:11.6 Mo, 0.100 02, 0.006 N2, 0.0015 H2 Ti:20V, 0.0574 O2, 0.0111 N2, 0.005 H2 These alloys were cold-rolled to 0.020 in. thick sheet. Specimens were heat treated in vacuum or in inert gas at temperatures >500°C and in a circulating air furnace at temperatures <500°C. Thin foils were prepared using standard techniques, described in detail previously." Dark field micrographs were obtained using high resolution technique. RESULTS Martensitic Transformation in Ti:11.6 pct Mo. Detailed study of the deformation induced martensite is not possible due to a spontaneous transformation which occurs near the edge of thin foils as shown in Fig. 1. Similar transformations have been observed in iron-" and copper-base13 alloys as well as other titanium alloys, but some observations specific to the Ti:1l.6 Mo alloy are listed below. a) The boundaries of these transformed regions are glissile and move under the influence of the electron beam during examination. b) Selected area diffraction indicates the transformed regions have the same structure as the matrix, being separated by tilt boundaries. The misori-

Jan 1, 1969

By R. E. Boehler, N. C. Ludwig

At Buffington Station, Gary, Ind., Universal Atlas Cement operates fourteen 8 x 101/2 x 155-ft cement kilns in mill 6 and two 11 x 360-ft kilns in the Harbor plant. The No. 11 and 12 kilns in mill 6 are equipped with Manitowac recuperator sections. This report describes studies in measuring exterior shell temperatures on several of these kilns and the development of a traveling radiation pyrometer with certain novel features. Preliminary Work: At first various temperature-sensing devices were placed on the steel shell: 1) crayons with calibrated melting points, 2) colored paints with temperature-calibrated pigments, 3) aluminum paints with temperature-calibrated binders, and 4) metal-stem dial thermometers. The colored paints and aluminum paints failed to indicate the temperatures correctly. The crayons and thermometers did indicate fairly correct temperatures, but it proved impossible to apply enough of these on the shell to detect all the potential areas where hot spots might develop. Furthermore, considerable labor was required to apply these sensors and read the temperatures. Consequently no further work was done with these devices. Formation of Hot Spots: In the burning or clinker-ing zone of a cement kiln, the thickness of the protective coating and thickness of the brick govern the amount of heat transmitted to the steel kiln shell. Usually the protective coating consists of 4 to 8 in. of fused cement clinker. The formation of a hot spot is usually caused by loss of coating? that is, localized areas of the coating become thin or fall away from the refractory. This is generally caused by excessive temperature in the burning zone over a fairly long period of time. It may also be caused by a sudden thermal change in the burning zone. Variations in raw feed composition and in feed rate require changes in the fuel and air rates, and when these are not appropriately altered, conditions may develop in the kiln that will result in loss of coating. Luminescence on the kiln shell indicates that a hot spot has developed to a point that usually alters the refractory&apos;s thermal conductivity properties. When this thermal weakness zone occurs in the burning zone of the kiln, constant vigilance is required to protect it by maintaining proper coating. Even so, it has been the writers&apos; experience that within a period of several days to about four weeks the hot spot usually recurs with greater severity. This necessitates shutting down the kiln and re-bricking the affected area. One of the prerequisites of a good burnerman is the ability to maintain a protective coating despite the many variables in operation. When he knows that it is getting thin or that an area has dropped off, he reduces the firing rate and kiln speed and brings feed into the affected area in an effort to rebuild the coating. But when powdered fuel is burned, the atmosphere of the kiln may prevent the burnerman&apos;s observing the condition of the coating closely at all times without taking off the fire. It is not considered good practice to do this frequently, as it imposes a thermal shock on the coating and upsets operation of the kiln. To help the burnerman scan the shell of the kiln along the burning zone, therefore, a radiation pyrometer, connected to a potentiometric recorder, was mounted on a slowly moving steel cable. The theory of operation, construction details, and adaptability of the radiation pyrometer are included in an excellent monograph&apos; and also in a textbook.&apos; Shell temperatures of the Atlas Cement kilns were measured with a Brown Instruments Div. low intermediate range Radiamatic unit, of range 200" to 1200°F, and a circular chart Electronik potentio-metric recorder, of range 500" to 1000°F. In Bulletin 59095M the supplier publishes standard calibration data (millivolts vs degrees Fahrenheit) for this radiation pyrometer, These data, however, apply only to flat surfaces having emissivities of unity. Calibration of Radiation Pyrometer for Use on Curved Surfaces: When applied to surface temperature measurements, the radiation pyrometer reading depends on the nature of the surface, the material of which it is composed, and also to some extent on the temperature of the surroundings. Although the present radiation pyrometer is designed to give a calibrated response under ideal (black body) conditions when used commercially, it must be calibrated empirically. The calibration procedure, given below, follows that described by Dike (Ref. 1, pp. 38-39). Calibration tests on plane and curved surfaces showed that the response of the radiation pyrometer was very

Jan 1, 1961

By Thomas H. Sheehan

The purpose of this paper is to present an application of computer technology to assist the mineral company financial executive in assessing exchange risks. The paper is divided into five parts: Background, Translation Approaches, Theory, Empirical Validation, and Conclusion. BACKGROUND Exchange risk results from a change in the rate of exchange between a host and a home country&apos;s currencies. Legitimate reasons exist for changes in the currency exchange rates among countries in a world with over a hundred different currencies. These reasons include: different economic growth rates, social factors, cultural heritages, and political motivations. The problem of exchange rate changes are perennial and exist whether the world operates on exchange rates or floating exchange rate practices. The cause of the problem is trade and international payment imbalances. If one accepts the premise that exchange rates fluctuate over time, then the mineral company financial executive faces a continual process of reassessment of the impact of exchange rate changes on the financial worth of his company. (1) The mineral company financial executive prepares balance sheets and income statements that are audited by certified public account- ants annually for shareholders, bankers, and tax authorities. The financial executive translates assets and equities denominated in foreign currencies into domestic dollars, e.g., Japanese firms convert to Yen, French firms convert to Francs, and so on. When figures from foreign subsidiary operations are consolidated into the balance sheets of the parent corporation, estimates of the company&apos;s finan-

Jan 1, 1977

By George Tryon, E. A. Barnard

The importance of the conservation of the waste heat contained in copper reverberatory furnace gases was realized very early by those in charge of operation at Anaconda. The first attempt to utilize it was in preheating the air used for combustion of the coal. This was done by forcing the air through ducts surrounding the flue-gas downtake and continued down beneath the furnace hearth to the firebox. Any small advantage gained by the heat transferred from the flue gases was more than offset by the losses sustained in cooling the hearth, therefore this process, after several trials, was soon discarded. It was first used at the Old Works as early as 1893 and again for a comparatively short time on the original furnaces at the Washoe smelter, or present works. Water-tube boilers came into general use very rapidly after 1890. Their adaptability for waste-heat steam generation, as well as the saving to be effected by the production of cheap steam from this source, was soon recognized. The first waste-heat boiler to be used in connection with a matte furnace at Anaconda was installed in September, 1900, at the "Old Lower Works." It consisted of a 100-hp. "Cook," vertical water-tube boiler. This boiler had 65 small perpendicular tubes arranged in concentric circles around a 10-in. tube in the center. These tubes were expanded into 4 ft. 4 in. inside diameter cylindrical steel top and bottom drums which served as the steam and mud drums respectively. This boiler was set in a cylindrical brick housing into which the furnace gases entered just above the mud drum and thence circulated upward around the tubes and steam drum to the stack. This installation proved unsatisfactory, presumably on account of difficulty with dust, and was soon abandoned. However, the possibilities for steam generation were undoubtedly encouraging for shortly afterwards (December, 1900) a 300-hp. Stirling boiler was installed, to be followed by two more in the spring of 1901. The choice of the Stirling type of boiler for application to copper reverberatory furnaces was particularly fortunate, as the arrangement of the tubes appears to combine to a great extent the maximum contact of the gases with the heating surfaces of the boiler and at the same time

Jan 1, 1934

By C. D. Woodward

THE Anaconda Copper Mining Co. purchases 25,000 kw. of electric power for its mining operations at Butte Mont. This power is delivered, over duplicate feeders, in the form of 60-cycle, 2400-volt, three-phase current, to five compressor plants, where most of the energy is used for driving air compressors. At the compressor plants are located the switching apparatus for controlling the 2400-volt power and distributing it to the various mines. At these points, also, there are a number of motor-generator sets for converting the alternating current to 275-volt. direct current for the haulage systems. Pole lines convey the power from the compressor plants to outdoor transformer substations at most of the mines. When it is not economical to distribute the power at the lower voltages in the mines, transformers and motor-generator sets are placed at strategic points .underground. All power is purchased on a maximum-demand basis, therefore there is installed at one of the compressor plants an eight-element totalizing graphic wattmeter. This instrument records simultaneously the value of all power taken at the numerous points of delivery, which not only eliminates the diversity factor but permits load dispatching between compressor and pumping plants, and thus materially reduces the maximum demand from the power system. As most of the mine hoisting is done, by 90-lb. compressed-air winding engines, the air-compressor equipment for the winding engines and mining operations is quite extensive. The standard air compressor has a rating of 7500 cu. ft. per min. of free air, and most of the compressors are directly connected to synchronous motors. The synchronous motors are designed for 80 per cent. leading power factor, thus facilitating power-factor correction of total mine load. Consequently by cooperation with the power company, the voltage of the power received at the compressor plants is constant.

Jan 2, 1922

By R. C. Troxell, S. C. Sun

EFFORTS to obtain definite quantitative data when employing the currently used bubble pick-up method1,2 as a pre-flotation investigation tool led to the adoption of the magnifying mirror method and the microscopic method modifications. Quantitative data obtained by these two methods were converted into bubble pick-up indices and bubble pick-up coefficients. Rough correlations were established between the calculated indices and the results of contact angle testing as well as actual flotation under the same conditions. The basic steps of the magnifying mirror method are as follows: 1—mixing 200 ml distilled water, sized and cleaned mineral particles of approximately 0.5 g, pH regulator, and flotation reagents in a glass beaker; 2—swirling the mineral particles to the center of the beaker to leave a clear circumference; 3—pressing an air bubble against the mineral particles for about 1 sec, and then moving the mineralized air bubble to the clear part of the beaker; and 4—dropping all the attached mineral particles of the air bubble by tapping the bubble holder, and counting the number of the dropped particles by looking at the magnified image in the mirror positioned beneath the beaker. This method is impractical for mineral particles which are transparent in water or finer than 200 mesh. The microscopic method is essentially similar to the above described magnifying mirror method, with the exception that the mineralized air bubble was drawn up into the bubble holder and subsequently discharged onto an externally placed watch glass, where the number of pick-up particles was counted with the aid of a microscope or hand lens. Drying was necessary when the discharged liquid interfered with the counting. The results of the bubble pick-up tests can be simply expressed in the form of the actual count. However, this can be misleading because the number of pick-up particles varies not only with the size of bubble but also with the size of particles. This short-coming is largely remedied by the use of the bubble pick-up index. as calculated from the following equation: PI = (pn/p) 100 [1] in which PI and pn are respectively the pick-up index and the number of pick-up particles under any test conditions, and p is the maximum number of pick-up particles of the same mineral under optimum flotation conditions, with the same size holder and particle. The bubble pick-up coefficient is a term coined to denote the difference between the bubble pick-up index of mineral particles in a liquid and that of the same mineral-liquid mixture plus a chemical reagent at the same pH value. For example, the difference between the pick-up index of a naturally floatable bituminous coal in a solution of water and kerosene and that of the same coal in water alone is a bubble pick-up coefficient. Compared with the contact angle method, the quantitative bubble pick-up method is inferior in accuracy but superior in sensitivity. Other advantages of the bubble pick-up method are that the apparatus can be easily assembled, the mineral sample is conventionally prepared, and the test procedure is relatively simple. References S. R. B. Cooke: The Flotation of Quartz Using Calcium Ion As Activator, Trans. AIME (1949) 184, p. 306. &apos;G. A. Last and M. A. Cook: Theory of Collector-Depressant Equilibrium at Mineral Surfaces. Paper presented at St. Louis Meeting, AIME (February, 1951).

Jan 1, 1954

By R. Schuhmann

Jan 1, 1965

By Frederic Benard

PRIOR to 1936, the Ontario Refining Co. received all incoming blister copper from The International Nickel Company&apos;s smelter in the usual form of 460-lb. cakes, or slabs. These were received in open cars in lots of 250 pieces. At the refinery the cakes were unloaded onto narrow-gauge cars, for convenient handling and pickup by charging cranes. In March 1936, an investigation was started on the feasibility of transferring converter copper in the molten state from the smelter to the refinery anode furnaces, a distance of 1 ¼ miles. Although common in steel practice, the transportation of blister copper in this form had not previously been attempted and a preliminary study of the various factors involved was therefore necessary. For this purpose, a series of experiments was made in which molten copper, removed at different stages during the furnace cycle, was held in a small portable holding furnace. This vessel was essentially a refractory-lined steel cylinder provided with ports for filling and emptying, heated by an oil burner. Dimensions of the steel shell were 3 ft. 10 in. diameter by 7 ft. 3 in. long, and thickness of refractories depended on the design and combination used for the particular experiment. The vessel was filled with approximately 2 ½ tons of copper at a predetermined temperature, the lining having been preheated to a definite point by means of an oil burner. All openings were well luted and temperature readings were made every 15 min. by means of an immersion-type thermocouple. In this manner the rate of heat loss resulting with different refractory design could be developed. The ratio of exterior surface to weight of metal was taken into consideration in comparing the experimental results with what might be expected for a full-sized unit, and observations were also made on type and degree of slag accretion. It was not possible to get as much information on this latter point as desirable, but all evidence showed that the problem would be control of slag build-up rather than attack on refractories. From the information derived, and in consultation with the engineering staff of the supplying company, an order was placed for the first

Jan 1, 1938

By Rees D. Rawlings, C. W. A. Newey

The aging characteristics of an Fe-11 at. pct Mo alloy have been studied by means of light metallography together with density, Young&apos;s modulus, and hardness measurements. The results were consistent with the precipitation of a single intermetallic compound during aging; overaging was slow relative to that in other iron-based binary alloys. The solution treatment temperature had a small effect on the rate of hardening whereas deformation prior to aging had a marked effect on both the rate of hardening and the peak hardness. The density data indicate that the compound precipitated is Fe3MO2 and not the Laves phase Fe2Mo. Analysis of the modulus and density results gave values for the time exponent for precipitate growth of approximately 1.0 and 1.5 for the alloy aged with and without prior deformation, respectively. DETAILED studies of precipitation hardening in bcc matrices have been confined largely to the effects of carbides and nitrides. In view of this and the growing technological interest in intermetallic compound strengthening, e.g., in maraging steels, a study of precipitation in iron-based alloys with a low interstitial content has been undertaken. This paper is concerned with the aging behavior of an Fe-11 at. pct Mo alloy; the mechanical behavior of the alloy will be reported later. The early work of sykes on Fe-Mo alloys showed that precipitation of the intermetallic compound was accompanied by an increase in hardness and a decrease in volume of the material. More recent surveys of the strengthening associated with precipitation have been made3-5 and, in particular, Elsen and wassermann4 showed that deformation prior to aging increased the rate of hardening. These latter workers also followed the precipitation process by means of dilatometry, electrical resistivity, and lattice parameter measurements. Their results confirmed that there is a decrease in volume on aging. Except for the work of Hornbogen on an Fe-20 at. pct Mo alloy, neither clustering nor the precipitation of a nonequilibrium phase has been observed in Fe-Mo alloys. Studies of alloys of lower molybdenum content475 indicate that the equilibrium intermetallic compound is precipitated during aging. However, there is some doubt concerning the nature of the equilibrium precipitate phase. According to the phase diagram constructed by Hansen,8 the phase should be precipitated. This phase has a rhombohedra1 crystal structure which is characterized by the formula Fe706,&apos; although the composition of the molybdenum-rich boundary corresponds approximately to Fe3Mo2. The version of the diagram proposed by Sinha, Buckley, and Hume-Rother indicates that the A phase, a Laves phase Fe2Mo, should be precipitated. Their observation of a Laves phase supports the earlier findings of Bechtoldt and Vacher,13 although, in a recent study of the system by means of diffusion couples, Rawlings and Newey did not detect the phase. The work presented here describes the effect of solution-treatment temperature, aging temperature, and prior deformation on the aging characteristics of the alloy as revealed by light metallography together with hardness, density, and Young&apos;s modulus measurements. In addition the density data are used in an attempt to determine the compound precipitated during aging. EXPERIMENTAL PROCEDURE A 29-kg ingot of the alloy was cast at R.A.R.D.E., Fort Halstead, from deoxidized, Japanese electrolytic iron and sintered molybdenum. The ingot was homogenized for 6 hr at 1473°K and then worked, with intermediate anneals, into 6- and 16-mm-diam rods and 6-mm plate. Chemical analysis of the alloy gave, wt pct: Mo, 17.5 (11 at. pct); C, 0.003; Si, 0.002; S, 0.005; P, <0.002; and02, 0.0098. Solution treatments were carried out under a dynamic argon atmosphere in a vertical, "crusilite" element, furnace which had a facility for rapid quenching into iced water. Except for the study of the effect of solution treatment temperature, all specimens were solution-treated at 1573" * 2°K for 1 hr. Salt baths were used for the aging treatments. Specimens for hardness, density, and Young&apos;s modulus measurements were produced, after heat treatment, from the stock rod or bar using a precision silicon carbide slitting wheel. As described later, the quenching treatment produced local plastic strain in the stock material; consequently, care was taken to ensure that the specimens were not prepared from these regions. Those specimens used in the studies of the effects of prior deformation on the aging behavior were strained in compression in a Denison universal testing machine. Specimens for light metallographic observations were mechanically polished on successively finer grades of diamond paste down to and then etched in either alcoholic ferric chloride or in a 2 pct nital solution. Vickers diamond pyramid hardness data were obtained using a 30-kg load. At least five impressions were averaged for each determination. Density measurements were made using a displacement technique in which each specimen was weighed in air and in dibromoethane at 296°K. The specimens were cylindrical and weighed 3 to 4 g; all weighings were made on a balance reading to 1 x 10"5 g. For each specimen the mean value of five weighings was used to calculate the density. The density of the dibromoethane was determined using the displacement procedure and a standard nickel specimen. The error in an absolute density value was estimated to be HI.01 pct. To obtain the density as a function of aging time a single specimen was used and the density meas-

Jan 1, 1969

By Magnus Troilius

The method of using the bromine process of determining sulphur in steel, described below, is in successful use at the Midvale Steel Works. Ten grams of drillings are weighed out and put into the 1/2-liter flask A, with long neck. The flask is connected with a wide glass tube C&apos;, which, in its turn, is connected with the absorption bulbs B, containing HCI, 1.12 specific gravity, and ahout 5 C.C. of bromine. The wide tnbe C causes the vapor to condense and flow back into the flask A during boiling. The bulbs B connect with a long glass tnbe, which may be made to carry off the bromine fumes through a hole in a window, or, better still, through a flue with powerful draught. The connections being made, 100 C.C. of boiling water are run in through the thistle tube T. The air is thus completely driven out of the flask. 100 C.C. of HC1 (about 1.19 specific gravity) are then run in. When the gas begins to run rattler slowly through B, heat is applied until boiling gradually ensues. The steel being completely dissolved, the apparatus is disconnected, and the contents of B rinsed out into a beaker of 100 C.C. capacity, into which a few C.C. of a concentrated solution of BaCI, have been previously introduced. Heat is then applied (best by means of the hot iron plate) until the bromine is completely driven off and the BaSO, has settled nicely to the bottom. The BaSO4, is then filtered off on a small

Jan 1, 1884

By Frank Firmstone, Kenneth Robertson

Peculiar crusts having appeared on certain irons made at Glendon and Pequest, which, in our experience, were entirely new, some analyses of them were made; and these analyses, together with an account of the manner of appearance of the crusts, are herewith submitted to the Institute. At Pequest the ores mere: & Peters, from Ringwood, N. J.; + roasted sulphurous ore, from Charlotteburgh, N. J.; and + red ore (decomposed magnetite), from Chester, N. J. The fuel was 7/8 Lehigh anthracite and + Connellsville coke, and the limestone a dolomite from Andover, N. J. The resulting iron varied in silicon from 0 84 per cent. in No. 1 foundry to 0.51 per cent. in gray forge; in phosphorus, from 0.81 per cent. to 0.55 per cent.; sulphur, 0.035 per cent.; manganese, 0.375 per cent. It was highly "chilling" in its properties, and very strong. In running, it invariably appeared to be of a lower grade than it really was; the higher grades scintillating as much as hard iron usually does. After getting into the moulds, and beginning to cool, a black crust began to show itself, seeming to exude from the pigs, till finally, when the iron was cold enough to break, it completely covered the face of the pigs. At this time it was dense black, but after some exposure to the air it ac .

Jan 1, 1884

By L. A. Tarshis, H. E. Cline

A stability criterion for a lamellar eutectic interface was derived previously1 assuming that the wavelength, A,. of the perturbation which grows most rapidly is much larger than the lamellar spacing. A. This assumption was required to permit averaging of both the interface temperature and composition over the complicated geometry of a lamellae. If this assumption is invalid, as has been suggested.2,3 then the problem becomes too complicated to solve completely. The first of these analyses1 did not calculate the wavelength. A,. of the initially unstable perturbation. whereas the more recent analysis.&apos; which led to a contradiction of this assumption. did not include one of the key factors for determining this wavelength. To rigorously determine the wavelength, the effect of the curvature of the perturbed interface (not considered by either of the above treatments) must be included. By omitting this term, one would be led to an incorrect conclusion regarding the magnitude of A,. but to an accurate criterion for stability as evidenced by the excellent agreement with experimental observations.&apos; In the case of single-phase alloys. the critical wavelength. A,. for instability can be calculated from the Mullins and Sekerka4 (M.S.) analysis which includes the effects of capillarity. In the following discussion, the M.S. analysis is applied to lamellar eutectics and the critical wavelengths calculated for reasonable growth conditions in Pb-Sn eutectic alloys. In order to apply the M.S. analysis to eutectics. one may substitute i) the effective liquidus slope.1 m*. for the single-phase liquidus slope and ii) the ratio of the bulk alloy composition. C,. to the average interface composition in the liquid (Ci = CE where CE is the equilibrium eutectic composition) for the distribution coefficient to give:

Jan 1, 1970

THE Fall Regional Meeting of the Institute, which has now for some years been held in cooperation with the Western Division of the American Mining Congress, will be held this year at Joplin, Mo., in the heart of the great Tri-State district. This year the Tri-State Zinc and Lead Ore Producers Association is joining in the meeting. The Society of Economic Geologists will also take part though not offering any papers. The district in which the meeting is held includes adjacent parts of Missouri, Kansas and Oklahoma. Out in the heart of a fertile prairie farming country, it is one of the major mining districts of the world. It produces normally approximately one-third of the zinc ore mined in the United States which is equivalent to nearly one-half the zinc since the concentrate has always been notable for the height of its grade. Even in the depressed business year 1930, the American Bureau of Metal Statistics credits the district with 434,460 tons of concentrates equal to 217,230 tons of zinc out of 1,503,095 and 576,630 respectively for the country as a whole. This was equal to about one-seventh of the world&apos;s output of zinc, more than that of any foreign country. In addition about 75,000 to 100,000 tons of lead is annually furnished by the same mines. Elsewhere we present a general description of the district prepared for this meeting by J. C. Heilman, a Lehigh graduate, who has spent the past eleven years there and has had charge of explorations for many of the companies.

Jan 1, 1931