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By Michael Hoch, Walter C. Wyder

The Cr-Ni system was investigated between 900" and 1400°C and 45 to 100 wt pct Cr. The Cr-Fe system was studied between 1200" and 1385°C and 70 to 100 wt pct Cr. Powdered alloy compacts were produced from high-purity chromium, nickel, and iron poulders. The compacts were sintered in an argon atmosphere and then machined into small, 0.030-in. diam cylindrical specimens. These were then heated by induction in the high-temperature X-ray diJfractwn camem under a helium atmosphere and irradiated with copper Ka radiation. From the results of the high-temperature X-ray diffraction patterns it can be concluded that chromium exists only in the bcc form, and that no eutectoid reaction occurs in the Cr-Ni system in the temperature interval 900" to 1400°C. The X-ray diffraction patterns are in agreement with the Cr-Ni phase diagram of Bechtoldt and Vacher, and Williams. It is possible that chromium undergoes one or more allotropic transformations between room temperature and its melting point. Most of the evidence was gathered from the study of the chromium-rich ends of the Cr-Ni and Cr-Fe binary systems. All the investigations rely heavily on indirect methods: thermal analysis, electrical resistivity, and micro-graphic inspection of quenched samples. In the present work the chromium-rich side of the Cr-Ni and Cr-Fe binary systems is studied, using high-temperature X-ray diffraction techniques. Thus the coexistent structures can be observed directly at temperature. PREVIOUS INVESTIGATIONS ~ansenl shows two possible Cr-Ni phase diagrams 1) a simple eutectic [Liquid =a-Cr(bcc) + y-Ni(fcc)], 2) a eutectic [Liquid+ P-Cr(fcc) + y-Ni(fcc)] and euctectoid [p-Cr(fcc) ==a-Cr(bcc) + yNi(fcc)]. The latter is based on the work of Grant and co-workers.2 Stein and rant'" placed the eutectoid composition at 1215°C and 68 wt pct Cr; their diagram is shown in Fig. l. Similarly, Sully3 also discusses the two proposed diagrams. Price and Grant,4 working on an isothermal section of the Cr-Ni- Fe ternary diagram at 1300°C, made no mention of a ß-chromium phase (fcc). The ß-chromium structure was also reported by Misencik 5 in the Cr-Nb(Cb) system. Williams 6 studied the Cr-Ni system using precipitation techniques. His work included the chromium and nickel solvus lines below 1250°C. He reported no ß structure nor any eutectoid reaction. The solvus lines which he produced were very similar to those of Jette, et al 7 below 1000°C. He concluded that Grant and coworkers2 had misinterpreted their data, and that effects which they had reported were actually due to the rapid and extensive precipitation of the nickel-rich phase. Bechtoldt and vacher8 used sintered powdered alloy compacts in an attempt to find the ß phase. They used metallographic and room-temperature X-ray diffraction techniques and also failed to detect the fcc chromium phase. They attributed the low slope of the chromium solvus at approximately 1150°C as the probable cause of the abundant precipitation obtained. They also stated that the precipitation was the probable cause for the abrupt discontinuities in the thermal analysis and electrical resistivity data which led to the conclusion that a eutectoid reaction existed. Fig. 1 also shows their diagram. Grigor'ev and coworkers9 investigated the polymorphic changes of chromium in the Cr-Ni phase diagram. Using standard microstructural and thermal analysis techniques, they published a phase diagram which contained five polymorphic forms of pure chromium and four eutectoid reactions. They stated that the room-temperature bcc chromium transformed to a fcc structure at 930°C, to bcc at 1300°C, to hcp at 1650oC, and then finally to bcc at 1830°C. The eutectoid reactions were placed at 850°, 960o, 1140°, and 1220°C. Also to be noted was the fact that the uppermost phase, the bcc above 1830°C, was different from the upper phase of Grant and coworkers,2 the fcc above 1840°C. Their eutectoid reactions, temperatures and compositions fall

Jan 1, 1963

By R. W. Shoenberger, J. D. Clendenin, W. L. McMorris, N. Schapiro, B. R. Kuchta, A. A. Terchick, R. J. Gray, J. G. Price

INTRODUCTION * The United States is fortunate in having enormous reserves of metallurgical-grade coals. Although these coals are better in quality and more accessible than most coals found throughout the rest of the world, the best grades of these coals are being depleted. Consequently, more efficient exploration tools and techniques, such as advanced methods of core drilling and logging, correlation by palynology,** stratigraphy, paleontology and petrography are being used to help assess the extent and quality of the remaining coal reserves. Exploration and assessment of new and existing coal properties become of utmost importance in determining (1) the economic justification for mining the coal, (2) the optimum design of the preparation plant and (3) the most effective use of the coal. Fortunately, the cost of mining coal has remained stable because of better mine planning, more efficient operations and increased mechanization of mining operations. However, increased mechanization raises the amount of impurities in the coal mined, and this requires more and better coal beneficiation to meet the more stringent quality requirements set by the market. Besides, mechanical miners also produce relatively fine coal and, to ensure maximum liberation of impurities, much of the coal presently being used must be crushed to a finer size prior to preparation. The bulk of all coals presently used in this country is mechanically cleaned, much of it at a lower specific gravity than in the past. This necessitates the use of new and improved processes and equipment for coal washing and recovery, such as heavy-medium cyclones and vessels, and froth flotation cells. However, because wet-cleaning processes are pre- dominant in the United States and fine coal retains large amounts of moisture, the increased production of cleaned fine coal accentuates the need for new or improved methods and equipment for dewatering and drying this coal. The larger amounts of coal being beneficiated and the use of new and improved beneficiation processes will aid in controlling and ultimately eliminating sources of pollution. Modem coal markets demand coals that meet rigid specifications. Most coals are purchased under contracts that specify moisture, ash, and sulfur contents, or heating value, depending upon the end use. There has also been a growing trend toward specifying other properties, including particle size and coking capability. These specifications may include not only the * Editor's note: Because of the numerous and varied contributions of the associate authors of this chapter, the text does not differentiate between sections prepared by each individual as has been done in other chapters. ** Palynology is the study of plant microfossils, especially spores, pollen, and other types of fossils not usually studied by paleontologists.

Jan 1, 1968

By J. P. Heller, H. B. Bradley, A. S. Odeh

A potentiometric model technique is presented for determining the areal sweep efficiency of a five-spot well pattern, at and beyond breakthrough. A sharp interface between displaced and displacing fluids is assumed. Although the prototype svstem is referred to as a waterflood operation, obvious changes in the notation and computations will adapt the results to other displacement processes. The results of the study include the following. 1. Areal sweep efficiencies for a five-spot well pattern, at and beyond breakthrough, for mobility ratios (displacing to displaced fluid) of 4:1, 2:1, 1:1 and 1:4. 2. Extension of potentiometric analysis to the investigation of the areal sweep efficiency beyond breakthrough in a five-spot pattern by the application of conformal mapping and conductive-solid models. 3. The use of layers of conductive fabric in representing mobility ratio changes in potentiometric models. 4. The development of a probe mechanism for probing conductive solids. The results obtained by conductive-cloth models agree with earlier areal sweep efficiencies at breakthrough obtained by Aronofsky and Ramey 1 on the potentiometric analyzer using electrolytic-tank models. Results beyond breakthrough differ from those obtained by the X-Ray Shadowgraph technique. Data from this study show that, for mobility ratios greater than one, water cut rises rapidly as fluid is produced after breakthrough. However, for mobility ratios smaller than one, a large increase in area swept resulted with only a small increase in water cut. INTRODUCTION In calculating reservoir performance of waterflood-ing operations and other fluid-injection programs, it is necesssary to estimate the areal sweep efficiency * before and after injected-fluid breakthrough into production wells. Influence of mobility ratio on oil-production history, before and after breakthrough for a five-spot well pattern, has been studied by X-Ray Shadowgraph techniques 2-5 and by gelatin models.6 In none of these investigations was the transition zone controlled experimentally. Steady-state anaiog techniques assume that a vertical and discrete interface exists between the displacing and displaced phase. Thus, when using a potentiometric analysis, it is assumed that no transition zone exists. To determine the areal sweep efficiency beyond breakthrough for a five-spot well pattern using the potentiometric analyzer, four principal problems had to be resolved. These were the following. 1. The laborious method of representing changes in mobility ratio in electrolytic tanks by means of contoured wooden blocks. 2. Vapcrization of the electrolyte solution during the study causing concentration changes and, thereby, variable conductivity. 3. The scale-limitation problem 7 that is accentuated by abrupt eiectrolyte depth changes. 4. A wellbore geometry problem. EXPERIhlENTAL EQUIPMENT AND PROCEDURES CONDUCTIVE-SOLID MODEL The theory, equipment and procedural techniques of the electrolytic-tank potentiometric model have been treaced excellently by Lee8 and by Muskat.9 By the use of a conductive solid to represent the fluid conductivity of the porous media, the need for contouring wooden blocks to represent mobility ratio was eliminated. It was found that a carbon-black coated fabric, Uskon D-16,** could be employed as a fairly uniform conductive media. This material, when stacked in appropriate layers and pressed together, can be used to represent changes in mo-

By Bryon W. Cheever

While working upon the processes which have been descaribed from time to time in the Transactions of the Institute for the estimation of these elements, I discovered that certain reactions take place under certain conditions which if overlooked, give erroneous results. Some of these reactions are new, to me at least. Estimation of Manganese. A weighed sample is dissolved in nitric acid and the manganese precipitated by potassium chlorate in the usual manner, care being taken to add some strong nitric acid at the last, and boil, to completely destroy the chlorate. Filter through purified asbestos, suck the filter dry with an aspirator; then wash with HNO3(1.40sp). gr.) until the acid comes through clear, and again suck dry with the aspirator. The nitric acid used for washing must be free from nitrous acid, for this acid reduces the peroxide of manganese; the lower oxide thus formed is dissolved by the strong nitric acid and is carried through the filter; some manganese also will nearly always be dissolved if the precipitate is washed with water. The nitric

Jan 1, 1886

By Y. A. Chang

Heat content values of tantalum monocarbide and tungsten monocarbide have been determined from 325" to 985°K by means of a drop-type diphenyl ether calorinzeter. Based on the values obtained in the present study and those available in the literature, best values lected and computed from 298. 15°K to temperatures close to their respectiue melting points. At temperatures higher than 1700°Kfor TaC and 27000 K for WC, values of Cp and related thermodynamic quantities were extrapolated based on the two Debye parameters: one corresponds to the metal sublattice and the other to the carbon sublattice. The contrzbutzon In the total specific heat due to lattice dilation was evaluated using the Nernst-Lindemann relalionship. The calculated values of Cp were in good agreement with the In view of their refractoriness, tantalum monocar-bide (TaC) and tungsten monocarbide (WC) are of con- experimentally determined ualues. Furthermore, the calculated values of the absolute entropies at 298.15"K were 5.03 and 4.15 in comparison to the experimental values of 5.05 and 4.15, all expressed in the unit of cal per degg-atom. Using the same Debye parameters, values of the linear coefficients of ther mal expansion for TaC and WC were calculated from absolute zero to their respective melting points using the Grüneisen equation. The calculated values are in excellent agreement with the experimental values available in the literature. Finally, the values of the bulk modulus of TaC from room tenzperature to temperature near its melting Point were also calculated using the equation recently derived by Anderson. No cot~ipari-son between the calculated and experimental values can be made due to lack of experimental data. siderable practical interest. In order to completely define these materials, it is necessary to know their thermal properties as a function of temperature. Tantalum rnonocarbide having a NaCl structure (B-1 type) melts congruently at 4250PK,1 while tungsten monoearbide with a simple hexagonal structure (Bh type) melts per itectically at 3049°K into melt and graphite.2 In the present study, the heat content values (from which

Jan 1, 1968

By Grover J. Holt

Open-pit mining on the iron range has been in a stage of transition for several years from the standpoint of mechanization. The most radical change in open-pit mining methods was started in open-pit haulage in 1937 with the departure from the then standard system of locomotive and car transportation and the advent of the heavy duty truck as a replacement. The initial use of trucks was followed shortly by the first installation of a conveyor belt for open-pit ore haulage. The growth of the combination of trucks for gathering units delivering to a conveyor system for transportation out of the pit, has been rapid and this transition appears to have reached a peak in 1949 with locomotives and cars now being used in only a few of the largest open pits. One point which must be considered, if we assume that the maximum equipment change- over point has been reached, is that the largest pits have probably passed their peak of production. Future ore replacement must come from smaller pits wherein the truck conveyor system has done an outstanding job.

Jan 1, 1950

By Oliver Bowles

WHILE vast quantities of limestone and dolomite. are used in metallurgy, the estimated production in 1926 being 23,860,000 tons, there are many problems connected with their use which have not received adequate study. The literature of metallurgy is notably lacking in comprehensive discussions of fluxing or furnace stone. Approximately 900 lb. of limestone is used for every long ton of pig iron produced in the blast furnace, but this important constituent of the charge receives little attention compared with the intensive study that has been applied to ores and fuels, the other important constituents of the charge. In an effort to elucidate some of the doubtful points, the writer has made a wide review of metallurgical literature, and has had the disappointing experience of finding not more than a paragraph or two on metallurgical stone' for each two or three thousand pages of literature reviewed. Furthermore, the limited information supplied is in some instances contradictory and even absurd. For example, a correspondent in a reputable metallurgical magazine classifies magnesia and silica together as impurities in flux "that must be melted and run off as slag." From the furnace operator's viewpoint it is desirable that as complete knowledge as possible be obtained concerning the effects of chemical composition and physical character of the stone on its action in the furnace and on the quality of the metal produced. A better knowledge of these features is advantageous also to the quarry operator in that it enables him to work more intelligently in producing stone that will best satisfy the metallurgists' requirements. The following pages comprise a brief compilation of data now available. Much of the information is well established and probably acceptable to most metallurgists. On some points there is room for debate, and the chief purpose in presenting a paper at this time is to arouse discussion which will throw more light on controversial points and thus assist the author in preparing a more comprehensive and accurate discussion of metallurgical limestone problems.

Jan 1, 1928

By J. J. Pye, J. B. Drew

Mzasurements of the surface diffusion coefficients of metals have been made. Diffusion profiles for the Ag-Ag system were obtained by means of a radioactive point source and a precision auto-radiographic technique. The activation energy for silver self diffusion (=8.1 kcal per mole) is lower than that previously reported (-10 kcal per mole) on poly crystalline wire by Nickerson and Parker. The bresent data indicate an effect due to parasitic volume diffusion at temperatures above 500°C. RELATIVELY few measurements have been made of the surface self-diffusion coefficients of metals. Nickerson and arker' measured the diffusion of silver over the surface of poly crystalline wires and estimated that the activation energy was 10.3 kcal per mole. Winegard and chalmers2 carried out measurements on both polycrystalline and single crystal surfaces but did not report a value of the activation energy. They found, however, that at temperatures between 250" and 400°C the diffusion coefficients were on the order of lo-' sq cm per sec and that there was an acceleration of the migration of silver on the polycrystalline sample when a change of surface shape occurred. Winegard and Chalmers used an autoradiographic technique, hereafter designated ARG, and Nickerson and Parker used a surface scanning geiger counter in order to determine the diffusion profiles. More recently, Hackerman and simpson3 measured the surface self-diffusion coefficient of copper at a single temperature (750°C), and the value of the diffusivity (- 10-5 sq cm per sec) is in agreement with that given by jostein from his thermal grooving measurements. This paper reports the results of an investigation of the surface self-diffusion coefficients of silver over a large temperature range and describes the adaptation of autoradiographic (ARG) techniques for the determination of diffusion profiles obtained from a radioactive point source. EXPERIMENTAL PROCEDURE The experimental procedure is a modification of the method employed by Hackerman and simpson3 in their measurements on copper. A brief description of their technique is as follows: A radioactive needle which sinters to the surface during the diffusion an- neal serves as the source of diffusing atoms. After the diffusion run the needle is removed and the surface is scanned with a shielded counting arrangement. The diffusion profiles reported in this paper were obtained by a modification of the above procedure which employs a precision ARG technique. Previous investigations in this laboratory and elsewhere51B have shown that under carefully controlled developing conditions and by the use of calibration sources a linear relation exists between the concentration of the isotope and the photographic density for values below unity. The use of ARG under these conditions has advantages over the counter scanning method in that cumbersome shielding and requirements for great mechanical precision of the scanner are eliminated. Also the ARG gives a complete picture of the surface which is advantageous in studies of anisotropic diffusion. A recording microdensitometer having a 0.1 p wide slit was employed. At low temperatures the disturbing effects of subsurface radiations are negligible. The diffusion anneals are carried out in the cell shown in Fig. 1. The needle is formed by grinding down a 1.0 mm rod of high-purity silver until a tip of 0.2 mm radius or smaller is formed. This tip is plated withA"' which becomes the source of the diffusing atoms that are detected by ARG. The needle carrier and the crystal holder, Fig. 1 are constructed of quartz and ports are provided in the holder pedestal which allow free vapor circulation ((2.0 oz) and the carrier apron fits snugly over the crystal holder cap, insuring that the needle does not move and scratch the surface. Temperatures are provided by a stabilized tubular furnace which can be quickly positioned around the cell, thus bringing the crystal up to temperature in a time that is short compared to the diffusing times. The diffusion anneals range from 2 hr for the high-temperature samples to about 25 hr for those at the lowest temperature. The possibility of vapor transport of the radioactive metal as a contributing factor in the diffusion profile was investigated in two ways. One method was to suspend the needle directly over a dummy sample, raise the temperature, for periods of time equal to the diffusion times, and then take an auto-radiograph of the surface. Negligible radioactivity appeared. In the second method a thin slot in the crystal face on one side of the source provided a "cong path" for surface diffusion. If evaporation was the primary source of surface atoms the region of radioactivity around the source would be symmetrical. This was not the case. The profile dipped abruptly at the edge of the slot but on the other side of the source the usual diffusion profile appeared.

Jan 1, 1963

By ARTHUR S. DWIGH

Discussion of the paper of W. W. NORTON, presented at the Salt Lake meeting, August, 1914, and printed in Bulletin No. 92, August., 1914, pp. 1993 to 1999. ARTHUR S. DWIGHT, New York, N. Y.-Mr. Norton's chief argument is directed against the idea that the D. & L. sinter is any better material for the blast furnace than the H. & H. product. He supports this by citing two experimental furnace runs. Reducibility.-To discuss a furnace record like that quoted by Mr. Norton for the five days' run in August, 1912, is manifestly difficult for an outsider, but a possible explanation for the poor reduction on Furnace No. 5, smelting D. & L. sinter, may lie in the fact that both sets of furnaces carried the same fuel charges. Other things being equal, if 11 ½ per cent. coke was right for the furnaces smelting H. & H. product, it Was too much for the furnace smelting D. & L. product, as I shall endeavor to show later, and incipient overfire, accompanied by higher leads in slag and matte, was induced. It may sound like a paradox to say that excessive fuel sometimes produces poor reduction, but it is a sad fact. In certain plants where practically the entire charge to the blast furnaces receives a preliminary treatment by being sintered on the D. & L. machines the peculiarities of this problem have had to be very carefully studied, for serious metallurgical difficulties presented themselves when the change was first made to D. & L. sinter in large quantities. Some of these plants had blast pots before they had D. & L. machines, and many opportunities were afforded for comparative study of this very point. There is reason to believe that, clue to the long period of blowing and the higher temperatures developed in the pots from greater mass action, the iron in the H. & H. product is present chiefly as Fe203, perhaps in the form of ferrites, while in the D. & L. product the iron is present as FeO. The fuel charge in the blast furnace must be so proportioned as to exactly meet the chemical and thermic requirements of reduction and melting. If ally of these functions have been performed before the material enters the furnace, a corresponding allowance should be made or the fuel balance will be disturbed and bad work will result. One of the functions of the coke is to reduce enough metallic Fe for the matte requirements, leaving the remainder of the iron as FeO to go into the slag. In smelting almost any other material than D. & L. sinter the iron must-be reduced from the higher oxides, Fe203 or Fe304, to the protoxide, FeO, before a true comparative basis is reached. Experience has shown that with about one-half D. & L. sinter on the charge the coke should-be cut about 10 per cent. This theoretical benefit is borne out by the practical blast-furnace results on a large scale in numerous plants. In fact, wherever this very important factor is ignored the evil symptoms of excessive fuel will be indicated,

Jan 11, 1914

By Ralph Arnold

WITHIN the past three weeks the price of crude oil in the Mid-Continent field has been cut 50 .per cent. Similar action has been taken, or probably, shortly will be taken, in most of the other fields of this country. This cut is very drastic. Is it justified? Some of the causes advanced for the cut are: that it is in line with the industrial downward readjustment now taking place throughout the country, and that there is an over-production of oil, which can best be slowed down by lowering the price of crude. In part, these two reasons are logically advanced, but such underlying causes as the great production- in Mexico have not been prominently brought forward nor the fact that it would be advantageous at this time to fill up the empty storage of many of the consuming companies at a low 'price. In order to properly comprehend the situation let us compare for a moment the production- of oil in the United' States and that in Mexico. Oil in the United States occurs in numerous often widely separated pools, varying in individual area, but each usually relatively extensive, compared to the area or gathering ground from which it is ultimately derived: It occurs in mod-erately porous reservoir rocks under such conditions of pressure, mobility and availability as to preclude its withdrawal except over a period of years-varying from 1 to at least 40 (average, say 15 years, depending on-the pool). One well will usually drain a limited area-2 to 10 acres-so that rate of withdrawal of oil under each owner's property is determined by the owner. - The important point to remember is that no matter how intensive the development, the oil reserves of -the United States cannot be materially exhausted' for at least 20 years, and the total available supply, not including shale oil, will probably require 50 to 75 years, or longer, for its withdrawal, the yearly rate of production decreasing slowly from this time on.

Jan 1, 1921

By Edward H. Robie

SHOULD the name of our Institute be changed? Perhaps one should say, should it again be changed, for until 1919 the name was the American Institute of Mining Engineers. When the American Institute of Metals joined our ranks we became the American Institute of Mining and Metallurgical Engineers. To make it a full mouthful, and strictly legal, one should add the word "Incorporated." At the June meeting of the Board of Directors it was suggested that this name was not a particularly happy one, especially so far as members of the Petroleum Branch, comprising a quarter of our membership, were concerned-not particularly appropriate as the name for the professional society for petroleum engineers. Apart from the petroleum group, the present name is felt by some not to be sufficiently comprehensive. Most geologists and many metallurgists, ceramists, and fuel technologists, for instance, are not engineers. They could never qualify as registered professional engineers under the licensing laws and yet they are valued and fully qualified Members of the AIME. The Directors, at the June meeting, thought the idea of a change in name should be presented to the membership for discussion, and suggested this column as the avenue of approach. Nine years ago Dean Steidle, of Penn State, recommended among other things that the name of the Institute be changed to "American Institute of Mineral Technologists and Engineers." In an editorial in Mining and Metallurgy in January 1944 objection was offered to this name but "American Institute of Mineral Engineers" was suggested. A special committee appointed by the Board to review Dean Steidle's suggestions (W. B. Heroy was Chairman) suggested that if the AIME were starting from scratch, the American Institute of Mineral Engineers might be a preferred name. It was not thought that the change suggested by Dean Steidle was one of major importance, and the comment was made that "the present name has gained prestige through many years and is cherished by our membership. An important element of 'good will' is attached to it and some of this would be unquestionably sacrificed by any change." In M&M for February 1945, Oliver C. Ralston went into the derivation of the terms mineralogy and metallurgy, and pointed out that both Mining and Metallurgical mean "digging," etymologically. He went on to show, with tongue in cheek, that if we want a short and all-inclusive name it should be American Institute of Geo-urgists, or, for euphony, Geolurgists. Oliver's brilliant development seems to have been received with speechless wonder! Should a decision ever be made to change the name, we think most members will agree that the American Institute of Mineral Engineers is to be preferred over anything yet suggested. "Mineral" has become, through usage, a much broader term than is indicated in the dictionary. Webster states that a mineral, in the true sense, must be inorganic, but Murray's Oxford English Dictionary seems more liberal, defining "mineral" as "any substance which is obtained by mining; a product of the bowels of the earth;" and "mineral oil" as any oil of mineral origin, as petroleum or shale oil. Certainly "the mineral industry" is ordinarily taken to include those activities based upon processing all the metallic and nonmetallic ores and deposits found in the ground, including the fuels. One advantage of this title is that the familiar abbreviation, "AIME" need not be changed. The advisability of maintaining a well-known abbreviation is evident, and was recognized, for instance, when the Committee for Industrial Organization became the Congress of Industrial Organizations some years ago. But if the petroleum engineers are the ones to be chiefly considered in revising the name of the Institute, it is by no means certain that they would feel that they are much more adequately recognized in a group of Mineral Engineers than in a society of Mining and Metallurgical Engineers. 'And then there remain, of course, the considerable number of professional members of the Institute who are not engineers at all. Comment from readers is invited.

Jan 1, 1952

Jan 1, 1881

President MRS. REED W. HYDE 84 Mountain Ave. Summit, N. J. First Vice-President MRS, WILLIAM A. SCHEUCH Trent St. Great Kills, S. I., N. Y. Second Vice-President MRS. THORNS E. LLOYD Box B Netcong, N. J. Third Vice-President MRS. H.. T. HAMILTON 24 Ridge Rd. Summit, N. J.' Fourth. Vice-President MRS. R. A. PALLANCH 1342 Laird Ave. Salt Lake City, Utah

Jan 1, 1939

By A. Kaufman

More than 3 trillion gal of water are used annually by the mineral industry. Of this, approximately 21/2 trillion gal are recirculated, the rest constituting intake water. The major users are natural gas processing plants and phosphate rock, sand and gravel, and iron ore producers. Water was used by the mineral industry for mining (6%), processing (64%), cooling and condensing (27%), and miscellaneous uses such as boiler feed and sanitary purposes (3%). Whereas total water use is dependent on the quantity of material processed and on the particular process requirements of an industry, recirculation is dependent on processing, as well as cooling and condensing requirements, quality of new water intake, and the necessity for treating new and discharged water. Consumed water, on the other hand, is dependent on the quantity of water recirculated, and temperature and humidity in the area. Based on this analysis, an increase in water use by the mineral industry of 21/2 times by 1985 is forecast. Wster intake, however, will only rise 62%, because of a substantial increase in recirculation. In one report of a special series concerning the water resources of the United States, the Senate Select Committee on National Water Resources, 87th Congress, estimated that water demand would double by 1980 and triple by 2000.' In view of the possible water deficiencies that might result from such expanded usage and the need for research guidance, the Bureau of Mines organized and carried out a statistical canvass of water use in the mineral industry for calendar year 1962. The data used in this paper, unless otherwise noted, are derived from that canvass.' The efforts in this paper are devoted toward summarization of the canvass and analysis of the data. SOME DEFINITIONS Intake: Water introduced from an external source for the first time into a given mine or plant regardless of quality. Intake water is also called new water, water withdrawn, or makeup water. Fresh Water: Water suitable for cooking and drinking. Saline Water: Water containing more than 1000 parts per million of dissolved solids. Contaminated Water: Water not suitable for domestic use, but excluding saline water. Recirculated Water: Water reused to conserve intake water. Solutions that are recycled primarily because of fixed metallurgical practices, such as copper leaching solutions containing sulfuric acid, are excluded. Gross Water Used: Recirculated water plus intake water. Also called total water used. Consumed Water: Water that is lost by evaporation, as well as water lost in product. Seepage and transferred water are not considered consumed. The use of either intake or recirculated water may result in consumption. However, because of difficulties in measuring consulmption, consumed water is defined as the residual between intake and water discharged from the mine or plant. Mineral Industry: For the purposes of this paper, mineral industry includes all metal and nonmetal surface and underground mines and their associated processing plants, as well as custom mills, coal washing plants and associated mines, petroleum and natural gas well drillers, natural gas processing plants, and secondary recovery operations. WATER USE IN THE MINERAL INDUSTRY Water used by the mineral industry constitutes a relatively minor fraction of the water withdrawn by all users. Data compiled by the U.S. Geological Survey in 1960 indicate that water withdrawals, exclusive of that used to generate hydropower, approximate 99 trillion gal annually.3 Our data indicate that water withdrawals by the mineral industry comprise only 1% of this total, or 2% of the water withdrawn by industrial users. Use by Industry: Water used by various mineral industries is shown in Table I. The table indicates that close to one-half of the gross water used by the mineral industry in 1962 was used by natural gas processing plants, followed by sand and gravel, phosphate rock, and iron ore producers. The largest aggregate users of water are also the largest users per dollar of product. For example, Fig. 1 shows that the natural gas processing and phosphate rock industries are very large users of water per dollar of product. Their recirculation per

Jan 1, 1968

THE following employment items are made available to AWE a non-profit basis by the Engineering Societies Personnel Service, Inc., operating in cooperation with the Four Founder Societies. Local offices of the Personnel Service are at 8 W. 40th St., New York 18; 100 Farnsworth Ave., Detroit; 57 Post St., San Francisco; 84 E. Randolph St., Chicago 1. Applicants should address. all mail to the proper key numbers in care of the New York Office and include 6c in stamps for forwarding and returning application. The applicant agrees, if placed in a position by means of the Service, to pay the placement fee listed by the Service. AIME members may secure a weekly bulletin of, positions available for $3.50 a quarter, $12 a year. MEN AVAILABLE Executive Engineer, Mining Engineer Graduate, 25 years' management experience from plant operation to vice president in charge of manufacturing for national concern. Management and operational experience in gypsum, asbestos, cement, paper, felt, asphalt products. West Coast or South location preferred. Prefer permanent position but would consider connection on consulting basis. M-663. Geologist and Engineer, E.M. (Geol.), Ph.D., 46, married, excellent health. Nineteen years' broad experience including appraisal, acquisition, large-scale exploration, special problems, planning, organization, and supervision in U.S., Africa, and South America. Sound approach and execution, writes clearly. Currently employed but available short notice. M-660. Mining Plant Designer. Over thirty years' broad mining experience. Graduate mining engineer, registered mechanical engineer, experienced structural engineer. Member AIME, NSPE. Fully experienced all phases design, from initial plant layout to final details. Excellent references. Presently employed but available reasonable notice. M-661-238-Chicago.

Jan 1, 1952

By Edel Moldenke

BURMA has long been known for its ruby, tungsten, and tin deposits, and, lately, for having the largest lead-zinc mine in the world, the Bawdwin Mine of the Burma Corpn. All the coal used, however, is imported from Calcutta; this is a bituminous coal of about 11,000 B.t.u., 24 per FIG. 1.-MAP SHOWING LOCATION OF COAL FIELDS AND TRANSPORTATION ROUTES. cent. ash, and costs about $8 per ton. Bituminous coal has not, thus far, been found, but many lignite deposits are known. The most promising lignite deposits are in the Namma field, Fig. 1, situated in the Northern Shan States of Upper Burma, about 30 mi. south of Lashio, the terminus of the Burma Railway, 750 mi. north of Rangoon. The

Jan 7, 1921

By H. J. French

AT THE request of a committee of the Engineering Division,1 National Research Council, a study of the properties of boiler plate at various temperatures up to about 900° F. (482° C.) has been instigated. The following is a report of preliminary tests made on two grades of ½ -in. plate and includes a description of the apparatus used in the determination of the proportional limit. Detailed reference to the many published investigations in connection with the properties of steel at various temperatures will be omitted from this report. Suffice to state that results obtained for variation in tensile strength elongation, and reduction in area with temperature are in substantial agreement with the effects now generally considered to be correct. Comparison of proportional limit values with results obtained by other investigators will be found in the conclusions.

Jan 2, 1920

By F. D. Rosi, C. H. Mathews

THE plastic properties of face-centered cubic metals below room temperature present a field of investigation which has not been extensively ex-plored. The work by Schmid and Boas1 has demonstrated the importance of temperature upon such properties as strain hardening and critical resolved shear stress. The work by Yamaguchi2 upon the shear stress as related to the number of slip bands accentuates the necessity for further experiments of a similar nature. The approach to a mechanical equation of state from the standpoint of thermal fluctuations and activation energies by Becker3 and more recently by Kauzmann4 further emphasizes the need for a quantitative and more comprehensive analysis of the dependence of fundamental plastic properties on temperature. The purpose of the present work was to investigate specifically: (1) The gross shape of the stress-strain curves at several temperatures, (2) the change in the critical shear stress as a function of temperature, and (3) the number and appearance of slip bands as a function of strain and temperature. Preparation of Specimens Single-crystal specimens of 99.996+ pct alumi-num, 1/2 in. in diam and 5 to 6 in. in length, were made by the Bridgman method of gradual solidification from the liquid state. The crystallographic orientation of the single crystals was determined from back-reflection, Laue X-ray photograms ac-cording to the method described by Greninger.6 In most specimens the Laue photograms showed double diffraction spots indicative of the lineage structure type of imperfection, discussed in great detail by Buerger.7 The angular spread of these spots was never observed to exceed 2". Most of the crystals were radiographed to insure against microporosity. In preparing the metal surface for optical microscopy, the following sequence of operations gave good results: The as-cast crystals were turned down in a lathe, 0.001 in. per cut, to obtain a 2.5 in. gauge length. The cold-worked layer resulting from this operation was removed chemically by etching with Tucker's reagent. Then the specimen was polished mechanically through 2/0 metallographic emery paper, after which it was etched again to remove the cold-worked layer resulting from the mechanical treatment. A 48-hr anneal at 580°C ±10°C followed so as to insure an essentially stress-free single crystal. After the annealing treatment, the specimen was electrolytically polished in a 2:l solution of methyl alcohol and concentrated nitric acid. With a current density of 10 amp per sq dm (decimeter) the time required to obtain a satisfactory surface varied from 10 to 12 min. The polish-ing was carried out for short periods of 2 min to avoid rapid deterioration of the solution as well as to enable the rotation of the specimen 180" for uniformity of polish. It was necessary to place the solution in a bath of dry ice in view of its explosive nature at room temperature. Etching of the electrolytically polished surface was accomplished by using the fuming etch-pit method recommended by Lacombe and Beaujard8 for high-purity aluminum. Method for Tensile Testing A modification of the loading equipment devised by Miller9 was used. In this apparatus, the specimen was suspended from a chain and gimbal arrangement (for axial loading) in a heavy steel framework connected at the bottom to a balanced 6:1 lever and bucket system. Loading of the specimen was accomplished by allowing sand to flow from a reservoir into the bucket suspended from the longer end of the lever-arm at a rate of approximately 3 lb per min. Strain measurements were made using the Baldwin SR-4, bonded, resistance-wire, strain gauge and an SR-4 portable strain indicator (type K), which permits a reading accuracy of 2 microinches per inch. For low-temperature study, the gauge was calibrated by measuring the elastic modulus of an annealed stainless steel rod, which is known to be independent of temperature."

Jan 1, 1951

By C. L. Magee, H. W. Paxton

The effects of testing temperature, frorn 77" to 420" K, and volume fraction of martensite on the micro-plastic response of unaged Fe-31Ni martensite-austenite aggregates have been determined. The kinetics of the aging phenomena which lead to a decrease in the microplastic response were also characterized. These determinations, supplemented by other experimental results, show that at least two mechanisms of plastic deformation give rise to the apparent softness of the quenched structures. Only one of these mechanisms is fully discussed in this paper The transformation of retained austenite to martensite during the application of stress leads, in specified conditions, to large microplastic strains. This deformation behavior cannot be described by normal transformation plasticity theory but is shown to result from the fact that stress-assisted formation of martensite is a possible deformation mode. The present results and further considerations of previous work lead to the conclusion that it is unnecessary to postulate a special work-hardening mechanism to explain the mechanical properties of unaged martensite. It is now generally accepted that dislocation motion can occur in many solids at stresses very much below the L'macroscpic" yield stress, e.g., 0.1 pct offset. This phenomenon has been investigated by a variety of techniques including measurements of elastic limit,' effective static elastic modulus,~ and irreversible deformation following stressing at low levels.3"5 Of particular interest to the work to be described are exper -iments conducted on the deformation of martensite in attempts to decide whether freshly quenched ferrous martensites are "hard" or "soft".6 Muir, Averbach, and cohenl and McEvily, Ku, and ~ohnston' have shown that as-quenched ferrous rnartensites can be plastically deformed at relatively low stresses. A difference between these two sets of experiments exists in that some diffusion of carbon would take place before testing in the experiments of Muir et a1. because the plain Fe-C alloys which they have tested transform to martensite well above room temperature. McEvily et a1. examined Fe-Ni-C alloys with Ms of about -30"~ and tested the alloys directly after quenching to — 195" ~ —a technique which obviates any appreciable carbon diffusion. Unfortunately, a characteristic of the alloys which transform below room temperature is that they do not transform entirely to martensite. The results discussed below will show that, because the transformation of this retained austenite under stress leads to plastic deformation, one cannot investigate the properties of martensite by such experiments. The existence of a second deformation phenomenon, which is not caused by retained austenite, is also established in the present work. In line with a previous suggestion,' it is believed that the second microdefor-mation mode is principally due to the internal stresses generated by the formation of martensite. To avoid confusion in the present report, the evidence we have found for this interpretation will be discussed separately in a brief note.7 EXPERIMENTAL Materials. The alloys were induction-melted and cast under vacuum; the resulting compositions are given in Table I. The ingots were hot-swaged to 2-in.-diam bar and further cold-swaged and/or cold-rolled prior to specimen preparation. The standard tensile specimens were machined from sheet. The gage section was 0.05 by 0.2 by 5 in.; 0.75-in.-wide ends had 0.2 5-in. centered holes for pinloading. The three-point bend samples were 0.075-in. thick and 0.6 in. bide. The distance between the outer loading points was 5.5 in. In order to establish a standard starting condition, all specimens were quenched to 77°K prior to annealing in vacuo for austenitizing. The temperature of the austenitizing anneal was controlled to + 5"~. The testing and aging temperatures were maintained by various liquid baths (nitrogen, 77"~; freon, 130° to 200°K; acetone, 200 to 300°K; silicone oil, 300' to 450°K) to better than il°K. Strain Measurement. The results herein were derived from both uniaxial tension and three-point bending experiments. For bending tests, the stresses and strains reported are those corresponding to the maximum fiber values. Normally, because of the small strains involved, very sensitive strain measurements are necessary to make microplastic measurements. However, because of the magnitude of the dilatation and shear involved in the martensitic transformation, the requirements in the present experiments proved to be less rigorous. In most experiments the plastic strain was evaluated by measuring stress relaxation and modulus defects. In this method, specimens are loaded rapidly to some predetermined load on an In-

Jan 1, 1969

G. F. COMSTOCK (author's reply to discussion *).-The discussion of this paper has been of such volume and interest as to constitute in itself a sufficient excuse for the paper, even though the paper itself may have been as much in error as some of its critics have maintained. Mr. Howard does not appear to realize some very practical facts that the opponents of his theory have advanced. Among these are: the coarsely crystalline fracture of the nucleus of a transverse fissure, so different from the smooth fatigue break around it; the occurrence of fissures in large numbers in certain heats or rollings of rails, while other heats or rollings do not develop them; and the much smaller proportion of transverse fissures found in rails rolled .from reheated blooms as compared with direct-rolled rails. These facts are not explained by Mr.

Jan 6, 1919