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E. W. Parker, Washington, D. C.: In connection with Mr. Blauvelt's paper, a brief sketch of the development of by-product coke-making in the United States may prove of interest. The first radical departure from the prevalent beehive oven to the by-product retort oven was inaugurated in 1891 by the Solvay Process Company, at Syracuse, N. Y. In that year was begun the construction of 12 Semet-Solvay ovens, which were completed in 1893. During 1893 these ovens produced 12,850 tons of coke, an average.of a little over 1000 tons each. In the following year the production amounted to 16,500 tons, not quite 1400 tons per oven. These 12 ovens were in reality an experiment, the success of which was attested by the addition to the same plant of 13 more ovens, begun in 1895 and completed in 1896. They were followed by the construction in 1896 of 25 ovens of the same type at Sharon, Pa., and 50 more at Dunbar, Pa. These 100 ovens represented the total number of Semet-Solvay ovens completed and in operation up to the close of 1897. The construction of 180 more, however—120 at Ensley, Ala., and 60 at Benwood, near Wheeling, W. Va.—was begun in 1897. The plant for the latter is laid out for double the number stated. The 60 ovens begun in 1897 have now been completed. An initial plant of Otto-Hoffman ovens was built at Johnstown, Pa., in 1895, and began making coke in 1896. One hundred and twenty additional ovens of this type were begun in 1896 and completed in 1897 at Glassport, near McKeesport, Pa. During the present year 100 Otto-Hoffman ovens are being added to the plant at Johnstown, and 400 of the same type are in course of construction at Everett, near Boston, Mass. The plant at the latter place is laid out for a total of 1200 ovens.

Jan 1, 1899

By R. S. Barneyback

Not much more is known about concrete today than was known to the Romans. For all the research only better tools have resulted to measure the quality of the materials that go into it." In this paper "some of the materials for lightweight concrete and their characteristics are considered and effort is made to indicate their effect on the end result — a structure of lightweight concrete." Lightweight concrete had noble beginnings. It is believed that the first specification for lightweight concrete was written by the Roman Emperor Hadrian in the early years of his reign, 117-138 AD. Hadrian, was an engineer by trade and an Emperor by adoption. He took considerable interest in the structures sponsored during his reign, even to the point of working out the structural details and preparing working drawings for some of the more prominent works in the vicinity of Rome. In order to reduce the dead weight of the 140 ft diam dome of the Pantheon he specified that the lightweight structural concrete members supporting this concrete and tile composite dome were to be fabricated from a concrete containing pumice and scoria. Still standing after 18 centuries of abuse, this structure has been described as the master effort of a great structural genius, the ultimate achievement of Roman engineering skill.' The Romans were the first to employ many concrete techniques we think of as modem innovations. Some unnamed superintendent noted that when a carefully measured amount of pigs blood was measured into each batch of concrete during mixing, the concrete was more durable and exhibited much better resistance to freezing and thawing climates. He no doubt, attributed this success to the appeasement of one of the gods who in return provided protection for the building containing this sacrificial offering in its walls. It is known today that the blood-entrained air in the concrete tends to make mixtures more workable, resistant to moisture penetration and more resistant to frost damage.

Jan 1, 1964

By A. L. Pranatis, G. M. Pound

Changes in length of copper foils of varying thickness and grain size were measured under such conditions of low stress and high temperature that it is believed that creep was predominately the result of interboundary diffusion of the type recently discussed by Conyers Herring. The surface tension of copper was calculated and results confirmed previous work within the limits of experimental error. Under the assumption of viscous flow, viscosities were calculated as a function of temperature and grain size. Predictions of the Nabarro Herring theory of surface grain boundary flow were borne out fully and the Herring theory of diffusional viscosity is strongly supported. ONLY a relatively few techniques for obtaining the surface tension of solids are presently available. Of these, the simplest and most straight forward is the direct measurement of surface tension by the application of a balancing counterforce. Thin wires or foils are lightly loaded and strain rates (either positive due to the downward force of the applied load or negative if the contracting tendency of surface tension is sufficiently greater than the applied stress) are observed. By plotting strain rates against stress, the load which exactly balances the upward pull is found and a simple calculation yields a value for the surface tension. The technique is of comparative antiquity, and solid surface tension values were reported by Chapman and Porter,' Schottky; and Berggren" in the early part of the century. Later, the filament technique became fairly well established as a method for determining the surface tension of viscous liquids, and Tammann and coworkers,'. " Sawai and co-worker and Mackh howed good agreement between the values of surface tension for glasses and tars obtained by the filament technique and by more conventional methods. With the increased confidence in the technique gained in these experiments, the method was applied to solid metals and the first reliable values of surface tension of solid metals were reported by Sawai and coworkers10' " and by Tammann and Boehme." More recently, Udin and coworkersu-'" have reported the results of experiments with gold, silver, and copper wires. Similar experiments with gold wires were carried out by Alexander, Dawson, and Kling.'" The excellent review articles of Fisher and Dunn" and of Udinl@ should be referred to for detailed criticism of the foregoing work and for discussion of underlying theory. In all the foregoing calculations, it is assumed implicitly that the material contracts or extends uni- formly along the length of the specimen and also that it flows in a viscous fashion, i.e., that strain rates are proportional to stress. For an amorphous material, such as glass, tar, or pitch, the assumptions are quite valid and good agreement is obtained with values of surface tension measured by other techniques. The values reported for metals, however, are occasionally regarded with misgiving, since it can be argued that, because of their crystalline nature, true solids can not deform in a viscous fashion. If this is true, then the results reported for solid metals over a long period of years are of only doubtful value. Thus it is clearly necessary that a mechanism be established that would explain both the viscous flow and the uniform deformation that has been assumed. Such a mechanism has been proposed by Herring."' Briefly, he suggests that, under the conditions of the experiment, deformation takes place by means of a flow of vacancies between grain boundaries and surfaces. This is a direct but independent extension of the theory proposed by Nabarro" in an attempt to explain the microcreep observed by Chalmer~.In a condensed form the Herring viscosity equation is TRL there 7 is the viscosity, T the absolute temperature, R and L grain dimensions, and D the self-diffusion coefficient. In its complete form, all constants are calculable and it includes such factors as grain shape, specimen shape, and degree of grain boundary flow. When applied to existing data, good agreement was obtained between predicted and observed flow rates. The theory received provisional confirmation from the work of Buttner, Funk, and Udin" who observed viscosities in 5 mil Au wire much higher than those in the 1 mil wire used by Alexander, Dawson, and Kling.'" More significant were the completely negligible strain rates found by Greenough" in silver single crystals. Opposed to these observations were those of Udin, Shaler, and Wulff'" who found indications of viscosity decreasing as grain size increased. Thus, complete confirmation of the theory was lacking in that the data to which it could be applied contained only a limited number of grain sizes. Hence, it was proposed that a series of experiments be carried out with thin foils of varying grain size up to and including single crystals, where, according to the Herring theory, deformation would occur only at almost infinitely slow rates.

Jan 1, 1956

By A. H. Lindley, Fraizer M. Stewart

For many years large mining companies were able to finance nearly all of their capital requirements from internally generated funds. However, during the last decade, funds needed for capital expenditures, dividends, and scheduled debt retirement have grown faster than cash flow. As a result the minerals industry has had to rely increasingly on other sources of funds. Getting the capital for new mining projects is a challenge, particularly for smaller companies. New methods of financing and new variations to old methods have been developed and more are needed. Commercial banks are short-term lenders. By policy their loans are limited to low risk loans-those made solely on the borrower's general credit, and secured loans where cash flow is sufficient to provide repayment within a comparatively short term. To maintain liquidity, banks prefer to make loans of less than seven years' term. If a longer loan is needed an insurance company or pension trust may take the long-term part.

Jan 1, 1971

By C. C. Mattax, J. E. Bobek, M. O. Denekas

ABSTRACT investigations in recent years have shown that rock wettability can exert a profound influence on the displacement of oil by water from oil producing reservoirs. Core analyses frequently show oil recoveries from preferentially water-wet rock to be significantly greater than those from preferentially oil-wet rock. Thus, an accurate prediction of water-drive or waterflood oil recovery is dependent on the evaluation of reservoir rock wettability. Laboratory and field studies have been undertaken to examine and develop methods which may be used to measure rock wettahililiy, to investigate factors which may alter the wettability of reservoir rock, and to determine the wettability of specific reservoirs. It has been found that measurement of the rate and volume of spontaneous imbibition of the wet-ting phase by a rock is a reliable and reproducible test for semi-quantitarive determination of preferential rock wettability. Laboratory tests have shown that the wettability of reservoir rock may depend on both the crude oil composition and the rock type. Field and laboratory tests have indicated that coring flulids and core handling techniques can cause significant changes in the wettability of rock surfaces. However, a few fluids, brine in particular, appear not to affect core wettability and may be used when coring to determine reservoir wettability. Core handling and packing procedures have been developed which preserve core wettability during storage and laboratory testing. The wetfability characteristics of six reservoirs have been evaluated by wettabilify tests performed in the field on fresh cores cut with brine or special water-base muds. The tests indicated that all six reservoirs are water wet; however, the de-gree differed from one reservoir to another. INTRODUCTION Although surface properties of reservoir rock and interfacial characteristics of rock, crude oil, and water systems have been discussed for many years, the full significance of these properties to the production of oil is still in the process of evaluation. It is known, however, that one surface characteristic—preferential wettability of the reservoir rock—-is of paramount importance when the reservoir is being produced by water-flood or water-drive mechanisms. The importance of rock wettability has been pointed out by several authors'.',%* who have found that pref- erentially water-wet cores flood more efficiently than oil-wet cores; that is, more oil is recovered from water-wet cores in the early flooding stages than from oil-wet cores. Other authors'," indicate that waterflood oil recovery from cores of intermediate wettability may be greater than that from either strongly water-wet or strongly oil-wet cores. These recent investigations emphasize that the true wettability of a reservoir must be known before the performance of waterflood or water-drive reservoirs can be accurately evaluated. When reservoir wettability is to be determined by core analysis, precautions must be taken to maintain the original wettability which can be altered readily during coring5 nd testing.' In the coring operation the core may be partially or completely penetrated by the drilling fluid which, if it contains surface active materials, may drastically change the wettability of the core. Also, improper core handling during stcrage and testing may change its wettability because of evaporation of fluids or exposure to oxygen or surface active contaminants. One purpose of this paper is to discuss methods for obtaining, preserving, and testing cores without altering their original wettability. In addition, the results of wettability tests on fresh and preserved cores from six reservoirs are presented where special precautions were taken to obtain samples without altering their wettability during the coring operation.

By H. L. Marcus, C. D. Turk

Titanium was physically vapor-deposited by electron beam high rate evaporation. Rates of 50,000 and 85,000Å per min at deposition temperatures of 480°, 535°, and 595°C were used. Deposited thickness ranged front 0.004 to 0.010 in. The evaporated titanium had a high degree of basal Plane texture. The specimens were tested in tension at temperatures ranging from 78° to 520°K. From the data, the yield stress, thermal component of the yield stress, and work hardening characteristics were found as a function of temperature, deposition rate, and deposition temperature. It was found that Taylor's equation, best fit the work hardening data with m = 1/2. MANY investigations have been made on the tensile deformation characteristics of commercial- and high-purity titanium.1"7 The data obtained from these experiments emphasize the fact that the mechanical properties are generally related to the method of production. The correlation of mechanical properties to production history arises from the dependence of impurity concentration on the extraction and melting technique used. Additional effects are derived from crystallographic texturing which can result from fabrication history. Lee and Backofen8 and other investigators9 have shown that crystallographic texturing in titanium sheet has a significant effect on the deformation characteristics. Bunshah and Juntz10 prepared high-purity titanium by high rate physical evaporation techniques. These authors found the deposited material to have a columnar structure with grain sizes ranging from 12 to 104 µ, depending upon the substrate temperature. The room-temperature strengths of the coarse-grained distillate were similar to arc-melted, rolled. and annealed crystal bar titanium. Commercial-purity titanium was also produced experimentally in our laboratory using high rate physical vapor deposition techniques. The commercially pure material has a finer structure than the high-purity distillate,10 and is highly textured. Since the method of preparation and degree of texturing affect the mechanical properties, a research program was initiated to determine the temperature dependence of the yield stress and work hardening characteristics as a function of high rate deposition parameters. This paper relates the results of the investigation. EXPERIMENTAL A) Material Preparation. The titanium was received in the form of commercial-grade 0.096-in.-diam wire which has a composition of 0.016 pct C, 0.0037 pct N, 0.110 pct 0, 0.011 pct H, 0.05 pct Mn, 0.051 pct Fe. balance Ti. The wire was continuously fed into a vacuum evaporation unit as shown schematically in Fig. 1. The deposition chamber was evacuated, purged with argon, and reevacuated to a pressure of 10-5 Torr which was maintained during deposition. A focused electron beam was used to evaporate the titanium from a water-cooled copper crucible. The titanium vapor was condensed onto a preheated titanium substrate. The temperature of the substrate was controlled within ±5°C for the deposition temperatures of 480°, 535°, and 595°C. Control of the input power enabled the use of two deposition rates. 50,000 and 85,000Å per min. The evaporated titanium had a final analysis similar to that of the input titanium, within experimental limits. B) Testing. The evaporated titanium was physically stripped from the titanium substrate and machined into tensile specimens with 1-in. gage lengths. In addition, tensile specimens of as received annealed 35-A titanium sheet with a 20 µ grain size and 45 pct cold-rolled 35-A were also prepared. All specimens were tested in tension in an Instron at a strain rate of 3.3 x 10"4 in. per in. per sec. Proportional limit has been used as a measure of yield strength. Tests were conducted at 78°, 220°, 300°, and 520°K. Metallography, X-ray diffraction, and electron microscopy were used to correlate structure with the deposition parameters and mechanical properties. Room-temperature X-ray measurements were made to determine the phases present. Pole figures and a scans were made to determine deposition texture. Because the vapor deposition was symmetrical about the normal to the substrate, there was no preferred di-

Jan 1, 1969

By AIME AIME

To accompanying photograph of the plant of the Beattie Gold Miner Limited, at Duparquet,. Quebec, is taken from the east and shows the open-pit from which the ore is taken during the summer. The buildings on the level ground above the open-pit are the change rooms, steel shop hoist building, compressor building, machine shop, warehouse, carpenter shop, and oil house. The main five-compartment shaft is shown west of the hoist building. The crusher plant adjoins the headframe and a long conveyor transports the fine ore

Jan 1, 1936

By S. W. Ross

A. A. CENTER*—This paper reminds me of the beginning of the work of the Electrolytic Zinc Company of Australasia. Early work for this Company, as some of you may know, was done at the Bully Hill Plant in California. After working there for some time Herbert Gepp, now Sir Herbert, came to the Anaconda Co. plants in Montana where I met him. He spent some months there, in fact almost a year if I remember rightly. That was when we were breaking in the new electrolytic zinc plant at Great Falls, Montana. From there he went back to Australia and started in on the plant there. I believe they had an original plant of about 20 tons per day of cathode zinc. We heard from them for some time, until they were able to go along on their own, and they have done very well ever since as you have heard. Their practice, (the flow sheet, the leaching practice), has been quite different as reported in the paper and apparently they are still following that practice to some extent. While the earliest work on selective flotation was done down in Australia, the big companies there, strange to say, were far behind the American companies in taking it up; and it is only in comparatively recent years they have gone to the alkaline circuit and dropped out thereby more of their iron and lead. The zinc plant now is up to a capacity of 100,000 tons a year and I believe that may be notched up to about 105,000. T. H. WELDON*—I would like to ask

Jan 1, 1950

By C. G. Dunn

It is well known that plastic deformation alters many of the properties of a metal and subsequent heat-treatment partially or completely restores these properties.l In the deformed or strained state, the metal is unstable and tends to change toward a condition called a "strain-free state." The transformation occurs through recovery, recrystallization, and grain growth—processes that may take place singly or in combination. The distortion of the lattice of an individual grain of a metal in a state of strain may be rather complex in nature, because plastic deformation produces: (I) dislocations within mosaic blocks; (2) elastic variations of the lattice spacings; and (3) gross alterations throughout the lattice, especially along slip planes, along composition planes between a grain and its mechanical twins, and along boundaries of deformation bands. These gross alterations are of the nature of bent planes or rotated regions of the crystal lattice and are revealed by a spread in the orientation of the grain. Although we cannot describe these strains and their formation accurately because of insuffcient knowledge, we can, nevertheless, use the information as well as possible to obtain a better understanding of recovery processes. In recovery, the lattice of a grain is not made anew as it is in recrystallization, but is improved or mended in such a way that the basic structure remains unaltered: Until recatly observations were .that recovery produced no marked changes in the shapes of spots in Laue diffraction patterns, whereas recrystallization did, but now it is known for silicon ferrite2 that Laue spots may become quite sharp entirely through recovery. Consequently, the shape of Laue spots alone would not be a suitable test to distinguish between recovery and recrystallization. There is considerable evidence that the micro-structure usually does not change visibly during recovery. Absence of a visible change in the microstructure, therefore, provides a sufficient test of recovery in many cases. However, including this observation in a definition of recovery as a necessary condition (this is usually done) is unfortunate, because recovery may, as will become evident later, produce new grain boundaries that are visible not only in the microstructure but also in the macrostructure. For the present, therefore, let us say that a necessary condition for a process to be one of recovery is that the principal orientation or orientations of a deformed grain be essentially unchanged throughout the transformation toward the strain-free state. Several transformations may occur that fulfill this condition, and the nature of the distortion in a grain indicates what these must be if the lattice is to be mended in part or fully. Consequently, it will be convenient as well as

Jan 1, 1947

By C. G. Dunn

It is well known that plastic deformation alters many of the properties of a metal and subsequent heat-treatment partially or completely restores these properties.l In the deformed or strained state, the metal is unstable and tends to change toward a condition called a "strain-free state." The transformation occurs through recovery, recrystallization, and grain growth—processes that may take place singly or in combination. The distortion of the lattice of an individual grain of a metal in a state of strain may be rather complex in nature, because plastic deformation produces: (I) dislocations within mosaic blocks; (2) elastic variations of the lattice spacings; and (3) gross alterations throughout the lattice, especially along slip planes, along composition planes between a grain and its mechanical twins, and along boundaries of deformation bands. These gross alterations are of the nature of bent planes or rotated regions of the crystal lattice and are revealed by a spread in the orientation of the grain. Although we cannot describe these strains and their formation accurately because of insuffcient knowledge, we can, nevertheless, use the information as well as possible to obtain a better understanding of recovery processes. In recovery, the lattice of a grain is not made anew as it is in recrystallization, but is improved or mended in such a way that the basic structure remains unaltered: Until recatly observations were .that recovery produced no marked changes in the shapes of spots in Laue diffraction patterns, whereas recrystallization did, but now it is known for silicon ferrite2 that Laue spots may become quite sharp entirely through recovery. Consequently, the shape of Laue spots alone would not be a suitable test to distinguish between recovery and recrystallization. There is considerable evidence that the micro-structure usually does not change visibly during recovery. Absence of a visible change in the microstructure, therefore, provides a sufficient test of recovery in many cases. However, including this observation in a definition of recovery as a necessary condition (this is usually done) is unfortunate, because recovery may, as will become evident later, produce new grain boundaries that are visible not only in the microstructure but also in the macrostructure. For the present, therefore, let us say that a necessary condition for a process to be one of recovery is that the principal orientation or orientations of a deformed grain be essentially unchanged throughout the transformation toward the strain-free state. Several transformations may occur that fulfill this condition, and the nature of the distortion in a grain indicates what these must be if the lattice is to be mended in part or fully. Consequently, it will be convenient as well as

Jan 1, 1947

By C. S. Barrett, D. F. Clifton

THE transformation that occurs in lithium and its solid solutions containing magnesium1,2 is similar in many respects to other diffusionless transformations of the martensitic type. This general similarity makes it desirable to investigate the transformation curves in detail. The current interest in the phenomenon of stabilization in martensitic transformations has created a need for a careful appraisal of possible stabilization effects in both cooling and heating transformations in lithium alloys. The effect of prior heat treatment on the temperature at which transformation begins and the effect of various temperature cycles in partially transformed alloys also merit attention. Limited data on some of these features were presented previously,' but the present studies have been made with improved apparatus, in which erratic fluctuations were smaller than in the earlier work, and include many independent determinations of certain critical observations. Material and Methods Geiger counter X-ray spectrometers were used: a Norelco instrument, original model, and a General Electric XRD-3. The low-temperature specimen holder has been described elsewhere." Specimens 10 mm in diam and 1.5 mm thick were held in firm contact with a copper block which was attached to the lower end of a stainless steel tube that extended up to a reservoir of liquid nitrogen. A heating coil on the tube permitted a controlled temperature gradient along the tube, so that desired temperatures and rates of heating and cooling could be obtained by controlling the heating current. The specimen was surrounded by an atmosphere of evaporated nitrogen in an insulated chamber having double cellophane windows. The temperature of the specimen was read by a thermocouple imbedded in it close to the irradiated area; the specimen could be held at constant temperature within 1°C for long periods. The body-centered cubic 200 reflection near 8 = 26" was used as the index of the amount of b.c.c. material present; occasional checks were made using the most suitable line of the low-temperature phase, the close-packed hexagonal 110 line near 8 = 29". Copper radiation was used throughout. A continuous record was made of the reflected intensities on a strip chart recorder, both when the peak intensity of a line was being followed and when the lines were being scanned at constant temperature. On the continuous recordings of peak intensity, periodic checks were made on the background intensity between the lines, and on the setting of the spectrometer for maximum intensity. The lithium-base solid solution containing 12.4 atomic pct Mg (33.3 wt pct) that had been used previously' was chosen, as it had a transformation range at relatively high temperatures, so as to permit wide temperature cycling within the range. Just prior to use a pellet was cut from the ingot,

Jan 1, 1951

By H. E. Hawkes, D. A. Barr

Time variations in the copper content of the sediments of streams draining mineralized areas were studied in two areas of contrasting climatic environment, one in northern and one in southern British Columbia. In each area, samples were collected and observations made of rainfall, stream discharge and air and water temperature at intervals throughout the summer season. Samples were analyzed for total and cold-extractable copper. Results showed a weak inverse relation between cold-extractable copper and discharge in two out of the three test sites in the southern area, and a decrease in ratio of COld-extractable to total copper over the duration of the test period at a highly anomalous site in the northern area. In suspended rock flour resulting from glacial erosion of mineralized rock in the northern area, virtually all the copper was found to be soluble in cold, dilute hydrochloric acid. None of the variations observed is sufficient to cause serious problems in geochemical sediment surveys. Systematic collection and trace analysis of stream sediments has seen wide application in recent years as a method of primary prospecting in primitive areas. Common practice is to collect fine-grained samples of sediment either from the active channel or from the flood plain near the channel. Samples are dried, sieved and the -80-mesh fraction analyzed after breakdown of the sample by a relatively strong attack, such as by fusion or by treatment with hot perchloric acid. Drying, sieving and rigorous chemical attack requires established facilities, either in a well equipped central laboratory or in base camp. Thus analysis for total metal involves a substantial delay from the time the samples are collected until the analytical data can be reported. An alternative system uses a cold aqueous extrac-tant in place of the hot acid or flux.4 Advantages of the cold-extraction techniques are that kits can be prepared for use directly at the sample site and that, in some problems, the patterns in cold-extractable metal, usually abbreviated cxMe, are more useful as ore guides than the patterns in total metal.' In the course of operational geochemical sediment surveys, a problem that has come up repeatedly is failure to reproduce anomalous values or patterns by resampling the same areas. The mystery of the vanishing anomaly has led to speculation as to whether there is a significant variation in the metal content of sediment samples with the weather or with the time of year. Review of the published literature shows that a number of experiments have been carried out on time variations in the metal content of stream water.1,2,5,7-9 The only published report on time variations in stream sediments that has come to the authors' attention, however, is by Govett,3 working in Northern Rhodesia.

Jan 1, 1963

Discussion of the papers of FREDERICH LAIST and HAROLD W. ALDRICH, FREDERICH LAIST and F. F. FRICK, W. L. AUSTIN, and STUART CROASDALE, presented at the Salt Lake meeting, August, 1914, and printed in Bulletins No. 91 and 92, July, and August, 1914. R. C. CANBY, Wallingford, Conn. (communication to the Secretary*). -Apropos of the experimental reduction of copper from cuprous chloride by fusion with ground limestone and coke, as described by Messrs. Laist and Frick, and also proposed for use at Chuquicamata., it might be of interest to refer briefly to the experience at Argentine, Kan., in the smelting of the suboxide of copper (as produced in the Hunt and Douglas process) containing appreciable quantities of chlorides. In the Engineering and Mining Journal of June 10, 1911, I. gave some account of what had appeared to be crucial difficulties with the Hunt and Douglas process, and how the filter-press difficulty had been so rapidly overcome after my discovery of the effect of the sodium salts in the leaching solutions. I also described the effect of the cupola furnace gases upon the lime rock with which I had replaced the coke in the absorption tower, which apparently showed the presence of considerable-chlorine, clue to the imperfect conversion of the subchloride to suboxide, as well as that clue to the difficulties of washing thoroughly the suboxide with the means provided, and also to the presence of chlorides in the cement copper which was smelted With the suboxide. The fumes from the cupola, when issuing direct into the atmosphere, were very dense and white, except when a hot furnace top caused a reddish tinge due to dust. These, fumes had a peculiarly suffocating effect, so that when they were blown over into the town the population suffered the greatest actual distress, not the mere annoyance which would have been clue to a disagreeable odor. The absorption tower had been built at the instance of the city authorities to abate this nuisance, and not with the idea of making any additional metal savings. A serious feature in connection with the Argentine experience with the Hunt and Douglas process was, that it had been implicitly assumed that there could be no metal loss in the Hunt and Douglas process itself, and that all attempts to locate the ruinous copper losses which were accumulating in the metallurgical accounts were devoted to the roasting department. It is possibly unfortunate for metallurgical advance along these particular lines that just about the time of this discovery of this previously unsuspected volatilization loss, in the smelting of the suboxide, the Kansas City company made a contract with the Western Union Telegraph Co. for its supply of copper sulphate and the Hunt and Douglas

Jan 11, 1914

G. M. TAYLOR,* Colorado Springs, Co1o.-I do not think the plan outlined in this paper would work at Cripple Creek. Most of our men have had a pretty good education. The Cripple Creek district is a lessee district-I do not think there is one mine operating in Cripple Creek to-day that does not have the leasing system. We have as many men leasing on our property as we have mining and every plan who is working for wages is looking for n lease-everyman has mined for him- self, he has been his on7n boss on n lease, either on our own property or

Jan 1, 1919

By George Stern

The purpose of this investigation has been to study one method for making ordinary carbon steel by the powder metallurgy technique. This method con- sists of pressing and subsequently sintering an intimate mixture of iron powder and gaphite in a suitable atmosphere to Produce a steel. Two types of iron Powder have been studied, electrolytic and reduced. The sinkring of mixtures of loose Car-bonyf iron and carbon black for several hours at I000 to 1100 C. (1830' to 2010°F.), followed by forging of the resultant ingots to bars, has been studied by Offermann.' TrailZ has reported on the properties of hydrogen-reduced and electrolytic iron powders, both containing 0.5 per cent carbon. Methods for making steel bodies by powder metallurgy have also been sug- gested by Goetzel13 who recommends the addition of steel powder of well-defined carbon content to pure iron powder, and Volterra,~ who suggests compaction and subsequent sintering of a mixture of steel powder, iron oxide and iron powder. Additional methods for making steel bodies by powder metallurgy have been reported in the literature by Kohering Allen,6 Balke,7 Wulff,8 Boegehold,9 and others.,0,11,12 It is felt that the method of pressing iron powder and graphite, as described herein, lends itself best to production be-Cause of the lubricating action of the

Jan 1, 1946

By George Stern

The purpose of this investigation has been to study one method for making ordinary carbon steel by the powder metallurgy technique. This method con- sists of pressing and subsequently sintering an intimate mixture of iron powder and gaphite in a suitable atmosphere to Produce a steel. Two types of iron Powder have been studied, electrolytic and reduced. The sinkring of mixtures of loose Car-bonyf iron and carbon black for several hours at I000 to 1100 C. (1830' to 2010°F.), followed by forging of the resultant ingots to bars, has been studied by Offermann.' TrailZ has reported on the properties of hydrogen-reduced and electrolytic iron powders, both containing 0.5 per cent carbon. Methods for making steel bodies by powder metallurgy have also been sug- gested by Goetzel13 who recommends the addition of steel powder of well-defined carbon content to pure iron powder, and Volterra,~ who suggests compaction and subsequent sintering of a mixture of steel powder, iron oxide and iron powder. Additional methods for making steel bodies by powder metallurgy have been reported in the literature by Kohering Allen,6 Balke,7 Wulff,8 Boegehold,9 and others.,0,11,12 It is felt that the method of pressing iron powder and graphite, as described herein, lends itself best to production be-Cause of the lubricating action of the

Jan 1, 1946

By P. F. Allen

WITH capacity of 51,000 tpd, the Morenci concentrator produces approximately 49,000 tons of tailing for final deposition. Disposal involves distribution of thickened tailing to dams in such a manner that solids can be used for dam construction and water can be impounded for reclamation. During early operation, although tonnage treated was lower, it was necessary to use orthodox disposal practices in the areas available for tailing. Trestles mounted on a series of dams, constructed of borrow material, carried the pipelines from which tailing were spigoted behind the dams. When adequate disposal areas were finally established, it became desirable to look for more efficient methods. The idea of placing the distribution pipe or manifold directly on the crest of the dam was advanced in 1945. After a period of testing, that procedure in modified form replaced the older trestle arrangement. Marked economies resulted, and time required to prepare dams for succeeding storage cycles was greatly reduced. The tailing disposal area for the Morenci concentrator lies south and southwest of the concentrator building. Ample storage space is available. A wide valley contains three sharply defined ravines lying on an average slope of 4 pct. The more central of these ravines, and the largest of the three, is known as Morenci canyon, which provides substantially more tailing storage area than the other two. Stargo canyon lies to the west; the other is appropriately named East canyon. Total area of the tailing disposal site is nearly 31/4 sq miles, or about 2000 acres. The storage area in use was somewhat more than 850 acres at the end of 1954, or 16 acres per 1000 tons of tailing to be stored daily. At the present time none of the east side dams are in regular use but they are available in emergency. There are five dams on the west side (in Morenci and Stargo canyons) as well as two auxiliary dams adjacent to No. 4 West and No. 5 West. This has made it possible to concentrate men and equipment in a smaller area with consequent savings in both manpower and machinery. Tailing Thickening: Tailing from the flotation process reaches the thickeners with a solid content of about 18 pct. The launder carrying this pulp is subdivided at a central point into seven launders carrying a proportional share to each of seven tailing thickeners, which are located in Morenci canyon close to the concentrator. Five of these thickeners are 300 ft diam and two are 325 ft diam. Thickeners are of the peripheral traction type and rakes travel at the rate of one revolution in 37 to 39 min. The entire installation provides 500,000 sq ft of settling area, or approximately 101/2 sq ft per ton of tailing to be thickened daily.

Jan 1, 1957

By Francis Crockard

DURING the past five years we have probably witnessed greater technological advances than in any similar period. Industry and science have steadily marched ahead. The makers of iron and steel products have watched with great interest the development of stream-lined trains, faster and safer airplanes, the entirely new science of air-conditioning and the widespread use of stainless steels. Since 1930, we have witnessed the erection of the world's largest suspension bridge, the largest and fastest ocean liner and the spectacular Boulder Dam, while even greater things are planned in these particular fields. Other indus-tries, too, have been moving ahead rapidly. This advance in a few years has been caused primarily by the fierce competition of the depression. Now, more than ever, is the emphasis placed upon quality and service. Makers of southern merchant pig iron have been no exception and have been confronted with increasingly strict chemical specifications and with much greater stress on physical characteristics than ever before. For example, sulfur in the iron must be held very low, competition demanding that it be in the 0.020's and low 0.030's; silicon content must be held within a very narrow range, and definite requirements of phos-phorus and manganese are an essential part of the specifications. Physical characteristics are becoming of increasingly greater impor-tance. The introduction of triple-skimmed, slow-cooled iron several years ago was the first step in this direction. Now there are a few customers who buy iron by chemical analysis and physical appear-ance, having found that the analysis alone is an insufficient guide to their requirements.

Jan 1, 1935

By Francis Crockard

DURING the past five years we have probably witnessed greater technological advances than in any similar period. Industry and science have steadily marched ahead. The makers of iron and steel products have watched with great interest the development of stream-lined trains, faster and safer airplanes, the entirely new science of air-conditioning and the widespread use of stainless steels. Since 1930, we have witnessed the erection of the world's largest suspension bridge, the largest and fastest ocean liner and the spectacular Boulder Dam, while even greater things are planned in these particular fields. Other indus-tries, too, have been moving ahead rapidly. This advance in a few years has been caused primarily by the fierce competition of the depression. Now, more than ever, is the emphasis placed upon quality and service. Makers of southern merchant pig iron have been no exception and have been confronted with increasingly strict chemical specifications and with much greater stress on physical characteristics than ever before. For example, sulfur in the iron must be held very low, competition demanding that it be in the 0.020's and low 0.030's; silicon content must be held within a very narrow range, and definite requirements of phos-phorus and manganese are an essential part of the specifications. Physical characteristics are becoming of increasingly greater impor-tance. The introduction of triple-skimmed, slow-cooled iron several years ago was the first step in this direction. Now there are a few customers who buy iron by chemical analysis and physical appear-ance, having found that the analysis alone is an insufficient guide to their requirements.

Jan 1, 1936

By K. D. Sheffler, R. W. Hertzberg, R. W. Kraft

The Ni-Ni,Ti lamellar eutectic alloy responds to unidirectional solidification by alig-nment of the platelets of the two phases roilghly perpendicular to the moving solid-liquid interface. X-ray diffraction and zetallographic experimenls show that the following cryslallographic relationships exist in the directionally solidified ingots: lamellar interface w [0001] Ni3Ti 11 (111 }Ni local growth direction (1120) Ni3Ti n (110) Ni These relationships are rationalized on the basis of the crystallography of the constituent phases. In recent years researchers in several laboratories have shown that an aligned or "controlled" micro-structure can be produced in many binary eutectic alloys by forcing the alloy to solidify unidirectionally in an elongated crucible.'-3 It also has been found that a unique crystallographic relationship often develops between the two phases in such a structure.4, 5 Since a parallel arrangement of phase particles in an alloy should, and, in many cases, does, produce unique and highly anisotropic properties, the alloys so produced are of potential interest in a variety of applications. Studies of these alloys are also of interest at the academic level because they help to improve our basic understanding of the way in which metals solidify. This paper reports the metallographic and crystallographic structure of another of these alloys—that between nickel and Ni3Ti. In a separate paper, hot tensile and stress rupture properties as well as deformation and fracture behavior of the same alloy are discussed.19 EXPERIMENTAL DETAILS AND RESULTS General Characteristics of the Eutectic Reaction. Several small exploratory Ni-Ti melts were made to resolve a conflict in Hansen6 over the eutectic composition. The alloy containing 16.4 at. pct Ti, Fig. 1, appeared metallographically to be closest to the eutectic composition, although small dendritic patches of proeutectic nickel are present. The eutectic morphology is lamellar and appears quite sharp and angular, indicating a strong influence of crystallographic factors upon the microstructure. Some of the eutectic nickel platelets are continuous with the primary phase, whereas in hyper eutectic melts a "halo" of nickel generally surrounded the proeutectic inter-metallic platelets, indicating that nickel is the nucleating phase in this eutectic reaction. Extensive precipitation of Ni3Ti has occurred in the primary nickel phase in a Widmanstatten pattern which makes the dendrites difficult to differentiate from the eutectic mixture. This phenomenon may account for discrepancies among the eutectic compositions reported in the literature. The sloping solvus line bounding the nickel primary solid solution explains the presence of the intermetallic precipitate. Poole and Hume-Rothery7 report that the solubility of titanium in nickel drops from 13.8 at. pct at the eutectic temperature (1304°C) to approximately 9 at. pct at 700°C (Ni3Ti, on the other hand, melts con-gruently and exhibits essentially no solubility for nickel or titanium). Lever rule calculations based upon Poole and Hume-Rothery's phase diagram indicate an increase from 21 vol pct Ni3Ti in the eutectic mixture at the eutectic temperature to 61 pct at room temperature. Selective point count measurements of the volume fraction of eutectic Ni3Ti platelets in the eutectic microstructure yielded a value of 46 i 2 vol pct, which required extensive precipitation of Ni3Ti from the nickel solid solution onto the eutectic intermetallic platelets during cooling from the solidification temperature. Influence of Directional Solidification. Nickel bar and titanium sponge of 99.9 pct purity were induction-melted in zirconia crucibles under argon in the proportion of 13.8 wt pct (16.4 at. pct) Ti to produce 14-lb master heats which were cast into investment molds yielding 5/8-in.-diam pins approximately 10 in. long. These pins were remelted under argon in horizontal zirconia boats and unidirectionally solidified to produce 1/2-in.-sq ingots approximately 44 in. long. Details of the experimental techniques and apparatus are described elsewhere.'

Jan 1, 1970