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By L. E. Young

GERMANY'S recent collapse and the occupation by the Allies of the coal fields of the Ruhr, the Saar, Silesia, Poland, and Czechoslovakia have focused attention on the postwar coal problems of Europe. American coal operators are interested deeply in what is happening in Britain, particularly in the discussion of plans to rehabilitate and reorganize the entire British coal mining industry, as such reorganization will probably determine the place Britain will occupy in the European coal markets for the next few decades. The continuing decline of British out-ut per man-shift, particularly during wartime, has resulted in a most serious effort to determine whether this unfortunate trend is due to the physical condition of the coal seams, poor management, poor engineering and planning, inadequate use of power and machinery, or failure of labor to co-operate with management.

Jan 1, 1945

By C. Y. Ang, C. Wert

Quench aging of supersaturated solid solutions of nitrogen in columbium takes place in reasonable times in the temperature range 300&apos; to 500°C. Changes in internal friction, hardness, and electrical resistivity are found to accompany this change. THERE is practically no detailed information in the literature concerning interstitial solid solutions in either columbium or tantalum. The fact that both of these metals are used extensively commercially in both pure and alloyed states makes studies of their properties of value. While the plan is to study both these metals and their alloys extensively, so far only a small number of measurements have been made. This paper presents data obtained in the initial investigations of columbium. The principal interstitial impurities of columbium are likely to be hydrogen, carbon, oxygen, and nitrogen. The first of these, hydrogen, is outside the scope of internal friction measurements at present and nothing quantitative is known about the initial hydrogen content of the specimens. However, it is believed that it is completely absent after the preliminary heat treatments are carried out. The carbon content of the original samples is low and can be reduced still further during sample preparation. Oxygen is normally present to some extent in columbium and can also be added or removed easily. Nitrogen is also normally present in small amounts and can also be controlled within limits. Since it is not possible yet to remove all the nitrogen from columbium and since it is possible to remove essentially all the oxygen and carbon, initial measurements were made on the alloy system nitrogen in columbium. In this sense then, the alloys are true binary alloys. Little is known about the effects of nitrogen on the physical and metallurgical properties of columbium, so it was necessary to perform some rather elementary measurements on the specimens. These measurements are described briefly in the next section and are discussed in detail in later sections. Scope of the Work That internal friction is associated with diffusion of nitrogen in columbium has been known for some time. It is similar in nature to that for carbon and nitrogen in a-iron. In these latter cases, the information obtained from internal friction has been useful metallurgically.&apos; and it is not too much to expect useful information from similar studies on columbium containing nitrogen. The technique of internal friction measurements is adequately described by Ke2 At a frequency of 1 cps the internal friction peak for nitrogen in columbium occurs at 300°C and that for oxygen at 160°C." So that all the measurements will be meaningful metallurgically, the internal friction has been calibrated by making a measurement of the damping at the two peaks and a measurement of oxygen and nitrogen content by chemical analysis. A comparison of the two gives the following calibration factor: To go from damping capacity expressed in terms of 1/Q to weight percent of oxygen and nitrogen in solid solution in columbium, multiply the peak values of internal friction by about 4 and 3 respectively." Data from which these factors were calculated are presented in Table I. The increase of electrical resistance of columbium caused by the addition of oxygen and nitrogen as interstitial impurities has been quantitatively determined. At room temperature the percentage increase is small for small additions of impurities (<0.1 wt pct); as the temperature is lowered it becomes an increasingly larger factor of the total resistance. An empirical relation has been established to express the resistivity at — 195°C in terms of weight percent of oxygen and nitrogen in solid solution. It is easy to make supersaturated solid solutions of nitrogen in columbium and to observe aging phenomena. The optimum aging temperature, as in the case for carbon and nitrogen in a-iron, occurs at the temperature for which the time necessary for a single place-change in diffusion is about 1 to 10 millisec. This means for nitrogen in columbium that significant property changes should take place for this alloy at about 400" to 500°C in reasonable time intervals. Results of such aging experiments are

Jan 1, 1954

By H. W. Schadler

The superplastic behavior of low carbon and manganese bearing steels has been evaluated. The results of elevated-temperature stress-strain rate and elongation tests are reported which indicate that high strain rate sensitivity (>0.5) and adequate elongations are achievable in ultrafine-grained steels 1 to 2 p, but at strain rates which are not commercially attractive. It has been demonstrated that the fine grain size is retained after long times and high strains if the temperature is kept within the range of the two-phase (a + ?) field. INTEREST in superplasticity has been stimulated by the desire to: 1) understand the origin of, and mechanisms responsible for, the large uniform elongations observed, and 2) exploit this property for commercial advantage in metal forming operations. Although the Zn-22 wt pct Al alloy presently being studied as a model material1-5 may find application in sheet forming and extrusion, the potential of super-plasticity should best be realized in large tonnage materials, such as steel and aluminum alloys. The degree of superplasticity in low-carbon and manganese-bearing steels has been evaluated. The results of elevated-temperature stress-strain rate and elongation tests on ultrafine grain size material are reported. Avery and Backofen6 and Hart7 have shown that geometrically stable flow leading to extensive uniform elongation in the tension test is associated with high values of the strain rate sensitivity, m, defined: Lozinsky had reported that titanium and zirconium experience permanent deformation if subjected to a constant load and cyclic heating through the temperature range of the phase transformation. Although strain rate sensitivities in excess of about 0.2 had not been reported previously for steel, permanent deformation had been observed11-13 in a wide variety of steels subjected to a constant load and cyclic heating through the temperature range of the a-? phase transformation. Thus by analogy, steel could be expected to exhibit high strain rate sensitivity but only in the a + ? condition. High strain rate sensitivity has been observed at 650°C (a + Fe3C), but not reported as such, by Bailey, Dickenson, and pearson14 in 1931 at a strain rate of about 10-9 per min. It then remained to determine whether high tensile elongations would be observed in a rate-controlled test at constant temperature and at what strain rate strain rate sensitivity values greater than 0.5 would be observed. Since previous experience8 had indicated the importance of fine grain size to realizing high m at reasonable strain rates, it was first necessary to produce an ultrafine grain size and then keep the grains from growing during the test. The results of this investigation show that fine grain size can be readily produced16 and maintained by restricting the temperature of testing to below the ? transus. Further, superplasticity (high m and large uniform elongation) is observed. However, the strain rate range is only marginally useful for commercial forming operations with the finest grain size produced. MATERIAL The material investigated initially was a 1.9 wt pct Mn, 0.42 wt pct C, hot-rolled bar previously used by Low and Turka1015 and available in the laboratory. The 0.500-in. round was cold-rolled to a 0.090-in. flat, annealed for 4 hr at 850°C in argon, air-cooled, and cold-finished to 0.050 in. Subsequently, four additional steels of the compositions given in Table I were investigated to explore the effects of manganese, carbon, and test temperature on the observed stress-strain rate behavior. These steels were melted under argon, cast to 0.75 by 2 by 5 in. slabs, hot-rolled at 850°C, surface-finished to 0.13 in., and cold-finished to 0.050 in. Sheet tensile specimens 0.200 in. x thickness with 1- or 2-in. gage length were cut parallel to the rolling direction. Table I also includes the nominal transformation temperatures for the AISI 1340 and the four experimental steels. EXPERIMENTAL PROCEDURE Production of Fine Grain Size. Ultrafine grain size (1 to 5 p) was considered essential for this studv. Grange16 has described two techniques for producing

Jan 1, 1969

By W. D. France, H. l. Burghoff

FABRICATORS of copper and copper alloys have contended with the problems of reconversion during the past year in endeavoring to return to the full-scale production that is demanded of them. The problems have not been easy, for the industry, like so many others, has had to deal with strikes of long duration, and material shortages, particularly in the raw materials, copper, zinc, lead, and tin. Despite all these obstacles, it was possible to gear production to new peacetime records during the latter part of the year. This was made possible not only by the use of multiple shifts of personnel, but also by the improved production equipment, the development of which had been stimulated by wartime necessity. The work of installing new and better equipment is still continuing, and virtually every company is engaged in improving or planning to improve its processes.

Jan 1, 1947

By M. I. Sherman, J. D. H. Strickland

USE of a hydrometallurgical approach to the oxidation of sulfide ores and extraction of metals therefrom may have advantages over the more common smelting techniques when a low grade deposit is difficult to concentrate or the subsequent separation of metals, coexisting in the ore, is laborious by any known smelting operation. For economic reasons, the most promising oxidants are either atmospheric oxygen or electric power. The use of oxygen, or air under pressure, has recently been revised. Pyrrhotite has been converted to iron oxide and elementary sulfur&apos; and a variety of sulfides have been treated by Forward and co-workers.2-4 Generally sulfate is the end form of the sulfur but with galena in an acid medium, elementary sulfur can be formed." For economic reasons chlorine and ferric iron salts are about the only possible alternatives to the atmosphere as oxidizing agents for base metal sulfides. If aqueous solutions of chlorine or ferric iron are employed, the reduction products can be oxidized electrolytically in situ and used again, thus acting as catalysts for electric power as oxidant. The use of ferric salts for this purpose is established hydrometallurgical practicea but, although chlorine gas has been employed in the dry state at an elevated temperature, its use in aqueous solution at or near room temperature has not found favor. The reaction of chlorine water with the soluble sulfide ion has been studied by several workers,7-9 and both sulfate and elemental sulfur are found as end products, the latter being favored by the presence of a low concentration of oxidant relative to that of sulfide in solutions of about pH 9 to 10. Of direct bearing on the work in hand are an early American patent" and a recent Austrian patent." The former advocates stirring powdered ore with an aqueous solution of ferric chloride chlorine oxides and chlorine. In the latter it is claimed that both metal and sulfur can be obtained by electrolysis, in a diaphragm cell, of a metal ore slurry in brine. Details in these patents are scant and no data or explanation is given for the mechanism of the reaction which, in the Austrian work, is attributed to the (unlikely) action of nascent chlorine at the anode surface. No mention is made of possible differences in behaviour between various ores. Apparatus A complication encountered when working with chlorine water is that a serious loss of chlorine occurs by gas partitioning unless an enclosed system is used and any air space in the apparatus is kept very small and constant. Arrangements were made, therefore, to take out samples for analysis without letting air into the system to replace the liquid removed. For convenience in studying a heterogeneous reaction the apparatus was so designed that a reproducible controlled stirring rate could be maintained and the ratio of surface area of ore to volume of solution was approximately constant throughout any experiment. The apparatus used is shown in Fig. 1. The ground ore was placed in the horizontal cylindrical vessel, A, of about 1 liter capacity, heated by a constant temperature circulating bath pumping water through the concentric jacket, B. By adding chro-mate to this water, an ultraviolet radiation filter effectively surrounded the reaction vessel, greatly reducing any possible photochemical decomposition of chlorine solutions. Stirring was effected by glass paddles, C, attached by an axle to a magnet which was rotated by another powerful Alnico magnet, D, outside the glass end, this magnet being itself rotated by an electric motor electronically controlled to constant speed. Speed could be varied from about 150 to 900 rpm and was measured and held to within 1 pct of a given value. The end of the reaction vessel remote from the stirring magnet was closed by another one-ended glass cylinder, E, connected by thin polyethylene bellows, F, clamped by screw clamps and watertight rubber gaskets to the main vessel. Through E, a glass electrode and calomel electrode projected into the solution and a hypodermic syringe pierced a small bung and allowed acid or alkaline to be added to maintain a constant pH. By pushing the fully extended bellows until the two cylinders touched, from 50 to 100 ml of solution could be forced out through a sintered disk into the three-way tap system, G, either to waste (for flushing purposes) or up into a 10 ml burette where the solution could subsequently be measured out for analysis. The ore samples were introduced at H, the tube being stoppered by a thermometer of —1 to +52ºC range, graduated to 0.1°C intervals. To prevent ore from being ground in the end bearings of the stirrer these bearings were pro-

Jan 1, 1958

By AIME AIME

THE second meeting of &apos;the Open-Hearth Committee, &apos;sub-division of the Iron and Steel Committee of this Institute, was held at the Hotel Cleveland, Cleveland, Ohio; on Oct. 13-15. On Oct: 12, the Open-Hearth Superintendents visited the plants of the Youngstown Sheet and Tube Co. and. the Republic Iron and Steel Co. These men were courteously entertailled by the two companies and every facility for a thorough inspection was furnished. Luncheon was severed at the plant bf the Youngstown Sheet and Tube Co. The meeting was opened Tuesday morning with addresses by J. V. W. Reynders, President of the Institute, and Herbert M. Boylston, Chairman of the Ohio Section of the Institute. E. A. Whitworth, of the Gathmann Engineering Co., presided at the meeting and L. B. Lindeinuth was secretary.

Jan 1, 1925

INTRODUCTION This chapter summarizes porphyry copper deposits within the State of Alaska. Prospecting for porphyry copper-type deposits in Alaska germinated during the 1940&apos;s, grew slowly during the &apos;50&apos;s, boomed during the &apos;60&apos;s, and matured in the &apos;70&apos;s. Although large expenditures have been made in the search for porphyry-type deposits, most accrued data lies dormant in company files. However, an adequate base exists in the literature for a general synthesis of areas that contain porphyry prospects. To simplify the summary, porphyry molybdenum deposits as defined by Clark (1972) are omitted. Description of deposits in their geologic setting permits some correlations between deposit characteristics and crustal environment. These correlations allow speculation about the genesis of the deposits. The summary also attempts to group deposits on the basis of general mineralogic characteristics because diorite model deposits are separated from quartz phenocryst-bearing hosts. Data presented in this chapter summarize observations by the author, published descriptions of specific areas and deposits as noted in the bibliography, and comments by various government geologists. E. M. MacKevett, Jr., D. H. Richter, and H. C. Berg of the US Geological Survey have been particularly helpful. Because few comprehensive descriptions of individual porphyry copper deposits exist for this area, much of the data presented is new to the literature. Details of structure, isotopic geochemistry, and petro- genesis for individual deposits are largely lacking and even the general geology of some belts is not well understood. Details on petrography of Alaskan porphyry copper occurrences are inadequate for construction of ternary diagrams (e.g., Figs. 36a, b, pp. 103, 104, for the northern Cordilleran orogen). Petrographic descriptions summarized in the text are largely from published descriptions whose sources are cited. Porphyry copper-type deposits in Alaska include deposits with pervasive pyrite that contain disseminated copper (but not necessarily coproduct molybdenum). Available data preclude differentiating the deposits by size. No Alaskan porphyry copper deposit is now in production but this is believed to be, in part, a function of economics. In some cases available geologic information is in- adequate for classifying deposits. Some de- posits included with porphyry copper may, with further exploration, be demonstrated to be some other genetic type. Alaska has three distinct porphyry copper provinces: the Hogatza plutonic belt, the Continental Margin belt, and the Interior belt. Each belt contains deposits with characteristic geologic features distinct from those of other belts. Fig. 24 shows the continental margin belt to extend inland from

Jan 1, 1978

By A. C. Losekamp, J. B. Conway

Thermal-expansion data for, tungsten, rhenium, tantalum, .molybdenum, niobium, W-25 pct Re, Ta-10 pct W, ant1 Mo-50 pct Re are presented covering the range from room tempature to 2500°C. In these measureMents, made in a resistively heated tungsten tube furnace operating in a helium atmosphere, data for rod and sheet specimens were found to be identical; in addition, arc-cast and sintered tungsten were found to yield essentially identical results. Optical rneasurenlents of thermal expansion .made in any atmosphere other- than vacuum are subject to a refraction error which can be quite substantial. Specimens tested in helium appear shorter than when tested in racuum and hence a special correction factor must be applied to the helium data in order to obtain accurate results. WHILE it is true that linear thermal-expansion data for many of the refractory metals have been measured to very high temperatures, it is also true that except in a few instances the data from various investigators are not in good agreement. This is particularly evident in the case of tantalum and niobium although some tungsten data have been reported which differ by as much as 40 pct from the data of other investigators. Due to the sensitivity of both tantalum and niobium with respect to impurity absorption during exposure to high temperatures, it is probable that this single factor accounts for the majority of the discrepancies in the thermal-expansion data for these metals. However, this same factor can probably not be employed to explain the existing differences in the tungsten data. In all probability, these are due to errors in the measurement technique, to material composition variations, or to changes which take place in the material during the heating process (e.g., additional densifica-tion resulting from heating a sintered specimen above the original sintering temperature). In view of the discrepancies which exist in the linear expansion data reported for many of the refractory metals, the current study was initiated in an attempt to resolve such differences. Also, no high-temperature linear thermal-expansion data were found to be available for several refractory metals. Providing such data was another objective of the current investigation. MATERIALS In this study test specimens were employed in either rod or sheet form and in several instances both arc-cast and sintered material were employed. Material compositions are presented in Table I. Helium gas was fed to the furnace at a rate of about 0.5 SCFH and no special purification procedures were employed. However, the helium contained less than 50

Jan 1, 1967

By Lombard Squires, W. K. Lewis, W. I. Thompson

Clays consist predominantly of hydrated silicates of alumina. The formula is frequently assumed to be A1203 . 2Si02 . 2H20,&apos;and certain of I. North Carolina. Low plasticity. 11. Same as I, after washing. Low plasticity. III. Tennessee. Good plasticity. IV. Pennsylvania flint fireclay. Low plasticity. V. Laredo, Texas. Very plastic. CaO/Na2O corrected for GO2. VI. San Antonio, Texas. Fine grained, highly plastic. Moisture and CO2 were determined together at 18.8 per cent. VII. Selected crude bentonite, California. " Data from R. Ries: Clays. John Wiley & Sons, New York, 1927. them undoubtedly have substantially this composition, but in general the ratio of silica to alumina is considerably higher. However, they always contain water of chemical constitution, as shown by Table 1.

Jan 1, 1935

By Wilbur H. Somerton

W. H. Somerton is to be commended for his application of the methods of dimensional analysis in combination with the results of laboratory drilling tests to obtain a significant formula for the rate of penetration for the process of rotary drilling. This formula is shown to be a consequence of a more general formulation developed by the discussor as a result of his investigations of the basic action of most methods of rock drilling by mechanical means—the momentary loading of a chisel-shaped tool on the surface of the rock at the bottom of the hole. Some of the author&apos;s conclusions are re-examined in the light of this general formulation. DRILLING RATE FORMULA The author selects a minimum number of the most significant variables associated with the rotary drilling process to set up his two dimensionless parameters. Only one variable is associated with the geometry of the bit —the bit diameter, D; only one variable is associated with the properties of the rock pertinent to drilling— the drilling strength, S; and only two independent variables are associated with the conditions of operation the weight on the bit. F, and the rate of rotation, N. The dependent variahle of interest is, of course, the rate of penetration, R. The results of the author&apos;s drilling tests show that the variable R that appears in the dimensionless parameter, RIND is approximately proportioned to the square of the variable, F, that appears in the other dimension-less parameter, F/D2S. This establishes the functional relationship between these two simple parameters that leads to the formulation of a third dimensionless parameter, RD1T2/NF1. This last parameter is a significant one for the rotary drilling process, in general, although the author properly limits the validity of his equations to his present test conditions. The author realizes that the numerical value of this parameter, C, is not a constant but may be a function of one or more additional dimensionless groupings of the many other variables associated with the rotary drilling process, e.g. some dimensionless measure of bit wear. The author&apos;s parameter is shown to be a special case of a more general dimensionless parameter, developed by the discussor. that is applicable to practically all methods of rock drilling by mechanical means, namely. RD2S/P. P is the rate at which mechanical work is done on the rock, and S is the drilling strength, a term originated by the discussor. S is defined as the ratio of energy input to the rock to the volume of rock broken

By R. W. Woodward, G. K. Burgess

minum bronze. Nearly all copper-base alloys are improved by rolling processes, but the copper-aluminum alloys seem to possess equally good properties when cast or rolled; this is a remarkable metallurgical fact. Another important property of these copper-aluminum alloys is their resistance to alternating stress. Many tests indicate that their resistance is greater in this respect than that of some steels, and I have seen instances when cast aluminum-bronze bolts have outlived five steel bolts in foundation work subject to severe shocks. I mention these various instances to indicate that work originally started as research for substitution of one material for another frequently develops 212 article which has properties not possessed by the original metal or alloy. I have dwelt particularly on the aluminum bronzes because recently I have done more special work on them than on other alloys, but I believe that the use of aluminum itself, in many combinations of metals, is a very important subject for investigation. Undoubtedly, after the war, the cost of aluminum will be reduced from its present price, and considering its low specific gravity it offers a very interesting and important field for research in the non-ferrous business. Naturally, if combinations containing aluminum can be developed in view of a probably increasing supply of metal, the cost will be reduced. This will benefit the industry generally and will immediately conserve tin. Bronzes, Bearing Metals, and Solders G. K. Burgess* and R. W. Woodward,† Washington, D. C.— From a metallurgical standpoint, there are several ways in which a reduction of the tin consumed in commercial non-ferrous and white-metal alloys can be effected. First, a reduction of the tin content of the alloy; second, substitution of part or all of the tin content by some other metal; third, a substitution of a different type of alloy, which in some cases also involves a change in mechanical design. The Bureau of Standards has been studying these methods of conservation for tin alloys, particularly in regard to babbitts and bearing metals, bronzes, and solders. Much of the information sewed by the Bureau was obtained from answers to questionnaires sent to manufacturers and users of these materials, so that, in general, any of the following suggestions or recommendations can be considered as being practical and as having already been thoroughly tried. Bearing Metals There is no question that the tin content of nearly all bearing metals can be reduced to some extent, and in some cases actually eliminated

Jan 1, 1919

By Charles H. Jacoby

In 1774 a Swedish chemist, C. W. Schule, first recognized manganese as an element. That same year Schule&apos;s associate, J. G. Gahn, isolated the element manganese for the first time. In 1856 the Bessemer process of steelmaking gave birth to the economic importance of manganese. Later, in 1882, Robert Hadfield discovered high manganese steels. Although the primary use of manganese is in the ferroalloy industry, two additional important uses for manganese are making chemicals and dry cell batteries. Manganese is also vital to plant and animal life. Various chemical compounds of manganese are used in fertilizers, feeds, glass manufacture, paints, varnishes, and for numerous medicinal and chemical purposes. For the study of industrial minerals and rocks, only the chemical and battery grade material is of concern, but for the sake of comparison, metallurgical aspects are included in this presentation. Although currently the world&apos;s largest consumer of manganese, the United States is producing only minor amounts of ore at the present time. This is due primarily to the fact that although huge deposits of manganese occur within our borders, all are of such low grade as to be economically unfeasible to mine. For many years various government agencies and segments of private industry have devoted sizable sums of money and time in an attempt to upgrade ores from the various deposits, and also in an attempt to recover manganese from blast furnace slags. In view of current world prices, and the quantity of high grade material available, there is little likelihood that any of these approaches will be found to be economically feasible in the near future. Geology and Mineralogy Mineralogy There are over one hundred minerals that contain manganese. These minerals vary from those with compositions that are predominantly manganese to those having only minor percentages. [ ] Geology From a geological standpoint most manga¬nese deposits are complex. In general, it can be said that all primary deposits of manganese are carbonates or silicates. The most productive and profitable have been those of sedimentary origin and residual concentrations. Examples of these residual types of deposits are associated with the metamorphosed lodes of Madhya, Pradesh, India, and the lateritic deposits of Orissa and Bihar, India; nodules in the residual clays of the Philippine Islands, U.S. southern Appalachians and Arkansas, Ghana, and Brazil. Sedimentary manganese deposits are best exemplified by the Nikopol district of Russia and the Tchiatouri area of Georgia, USSR. Hydrothermal replacements are characterized by the rhodochrosite deposits of Butte and Phillipsburg, Mont. In general, the hydrothermal type deposit has not resulted in any large tonnages being produced, but may have given

Jan 1, 1975

Discussion of the paper of E. G. Woodruff, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 78, June, 1913, pp. 1001 to 1010. F. A. LINFORTH, Butte, Mont.:-I have not had an opportunity of reading this paper thoroughly, but I would like to call attention to the possible use of the contours on fault planes. It is obvious that if the contours of fault surfaces call be determined, we will be able to determine the axes of the hollows in the fault surface. It seems probable, and there are examples to point to the accuracy of, the assumption, that the axes of these hollows may be the direction of movements on the faults, and if that is true it will aid materially in locating faulted ore bodies or the shoots of ore on the opposite sides of faults. A few such contour maps of faults have been attempted on some of the faults of the Butte district, and those faults which are believed to have the nearly normal movement exhibit for the axes of these hollows a line nearly up and down in the plane of the fault, but in those cases where the throw is believed to bee nearly horizontal we find that the axes of the hollows are almost horizontal lines. In other words, the movements on faults, I believe, would be more nearly indicated by the larger grooves in the fault surfaces than by the small slickensides and minor hollows that are seen, so that contour maps might be valuable in geology in that way. C. W. GOODALE, Butte, Mont.:-I received a letter from Mr. Woodruff asking me to take part in the discussion of his paper, but I have not had time to give the paper any study. I can certainly add my opinion to that of all the engineers here that the topographic maps of the government are of great aid to the engineer. When I visit a new district, the first thing I do is to see if that district has been covered by the U. S. Geological Survey avid if topographic map has been issued. And I find that some of the younger engineers frequently come into my office to see if I have such maps. I know in some cases the reports made out by engineers contain copies of these topographic maps, or clippings from them. I am sure that. the topographic maps furnished by the government are of very great value to our engineers.

Jan 11, 1913

Discussion of the paper of G. Howell Clevenger and Bhupendranath Ray, presented at the New York Meeting, October, 1913, and printed in Bulletin No. 82, October, 1913, pp. 2437 to 2475. ALLERTON S. CUSHMAN,* Washington, D. C.:-I am very much interested in the subject matter of this paper. I have had occasion to speak to this question before. There has recently been so much written and said and claimed about the effect produced by the addition of small quantities of copper to steel that there is certainly an impression abroad that a new and wonderful cure-all has been discovered. Are we facing a method of alchemy by which, at the expenditure of very little trouble and only a few cents&apos; worth of copper per ton, the well-known characteristics of steel with respect to some features are so marvelously changed as in effect to produce a new metal ? I am a great believer in the future of the iron and steel alloy field. I do not think that with all the advances we have made in metallurgy we have begun to scratch the possibilities of usefulness to mankind in the exploration of the alloy field, and I include in that alloy field even what might be designated as the dilute alloy field; that is to say, where a very small quantity of a metal alloyed with iron and steel confers upon it some new or extraordinary qualities. With respect to many of the physical characteristics of the copper-iron or copper-steel alloys I am not particularly competent to speak. With respect, however, to the investigation of corrosion problems and with respect to claims made with regard to resistance to corrosion, I am competent to speak insofar as I have specialized to some extent in that field and have given up a great deal of my time for a great many years to a study of it. Some years ago, being particularly interested in the study of corrosion problems, I received the very generous permission of a large manufacturing concern to use their large open-hearth furnaces any way I saw fit for exploring this particular field. There is not a metallurgist in this room who will not realize the generosity of a manufacturing company who would permit a man to pursue a theory and give him as his material to work with 60 tons of molten metal. At all events, I threw copper into the open-hearth furnace. I explored this alloy field, not in a ittle crucible in which I had to take out portions and have them

Jan 12, 1913

The 140th meeting* of the American Institute of Mining and Metallurgical Engineers was held in New York, Feb. 16 to 19, 1931. It consisted of the annual business session, twenty-six technical sessions at which 149 papers were presented, two round table discussions, two meetings of the Board of Directors, three meetings of Section Delegates, two formal lectures, four group dinners and 11 group luncheons, luncheon daily for members and guests, 20 committee meetings and conferences, the annual reception and dinner dance, an informal dance, a smoker-dinner, two meetings of the Woman&apos;s Auxiliary and a special program of entertainment for the ladies. Former members of the Rocky Mountain Club and friends lunched together at the Engineers Club on Tuesday. The proceedings of the Iron and Steel Division included four general technical sessions, an Iron Ore Round Table, the Howe Memorial Lecture, the Division luncheon at the Engineers Club Wednesday noon, a session each of the Executive Committee and the Committee on Nondestructive Testing, a luncheon each of the Committee on the Manufacture of Alloy Steel and the Blast-furnace Conference Group, and a dinner of the Committee on Physical Chemistry of Steelmaking. Dr. F. F. Lucas delivered the Howe Lecture, the title of which was "On the Art of Metallography." The Institute of Metals Division held three general sessions, its annual lecture, which was delivered by Dr. Arne Westgren and entitled "X-ray Determination of Alloy Equilibrium Diagrams," and a Division dinner at the Hotel New Yorker Thursday evening, at which Dr. G. W. Thompson was the principal speaker. The Executive Committee assembled at a luncheon on Thursday. A round table on Coal Land Valuations, a general technical session and a Division luncheon were held by the Coal Division. C. E. Bockus, President of the National Coal Association, made an informal talk at the luncheon which was held at the Engineers Club Monday noon. The Petroleum Division held six general sessions, including its annual production symposium. The annual dinner was held at the Engineers Club Thursday evening. A Gold Supply Symposium was the feature of the proceedings of the Committee on Mining Geology. This Committee also held a general session and a luncheon meeting. Sessions were held by other Technical Committees as follows: Mining Methods, 2; Mine Ventilation, 1 (besides which the Committee on Mine Ventilation Code held a meeting); Ground Movement and Subsidence, 1; Milling Methods, 1; Nonferrous Metallurgy, 1; Engineering Education, 1 (also a Committee luncheon); Non-metallic Minerals, 1, and Geophysical Prospecting, 2.

Jan 1, 1931

Members of Fifty Years or More Lawrence Addicks &apos;02 T H Aldrich &apos;98 Walter H Aldridge &apos;89 Eugene Ant. &apos;99 George H Ashley &apos;99 R M Atwater, Jr &apos;97 James B Bailey &apos;00 Samuel Barker, Jr &apos;00 John F Berry &apos;93 Charles A Bohn &apos;93 W S Boyd &apos;02 H C Boynton &apos;01 H A Brassert &apos;99 Arthur C Brinker &apos;01 James F Brophy &apos;01 Davenport Brown &apos;02 Donald C Brown &apos;01 Victor B Buck &apos;98 Frederick Burbidge &apos;87 Frederick P Burrall &apos;97 John Cabot, Jr &apos;99

Jan 1, 1952

By Grimes, J. A.

EXTENSIVE discovery &apos;and rapid exploitation of orebodies within the past half century have attracted many able geologists to the mining industry and furnished them a wealth of data from which to develop theories concerning ore genesis. By tosting and elimillating theories which are not sufficiently sup- ported by fact, or which are based on inaccurate observation of field data, the trend of geological opinion has . moved strongly in certain directions until, at the present time, large numbers of geologists subscribe to a broad concept of .ore genesis that I would summarize as below:

Jan 1, 1928

By Persifor Frazer

I DESIRE to say that, owing to the number of papers which have been more or less crowded at this session of the Institute, and the fact that, as one of the Local Committee, I have the distinguished honor to feel somewhat like one of the hosts, I should not tax the patience of members at this late hour, but would have my paper read by title were it in any way possible to do this. But the task I have set myself this evening is to present to the eyes of the members of the Institute certain objects which have occupied more or less of my time during the last eighteen months or two years. The objects I allude to are some of the igneous rocks of this country, which, until quite recently, have been less understood than any others. It will be well known to some of the members that some of the cooled lavas of a previous age of our planet, when not directly coarsely crystalline and granular, were considered and spoken of as " natural glasses," or perfectly uncrystalline, vitreous, or hyaline masses of matter. Among the first results of the use of the microscope was the dispersion of this fallacy. Sir David Brewster, Mr. H. C. Sorby, and William Nichol (the discoverer of the celebrated calcite prism, which bears his name), had, with greater or less success, examined sections of various rocks and minerals, both by transmitted and reflected light, and also in the form of powder. But, until the genius of Vogelsang undertook the subject, these investigations had no permanent value, nor did they constitute an independent line of mineralogical and geological research. Since the close of his labors, by Vogelgang&apos;s premature and much-lamented death, the subject has been made one of renewed interest by his brother-in-law, Ferdinand Zirkel, as well as by Rosenbusch, Tschermak, and many others abroad, and at home by the commencement of a systematic study of the traps of Connecticut by Messrs. E. D. Dana and G. W. Hawes, of New Haven, and by the splendid set of described sections of the traps of the West which have been furnished by Zirkel to illustrate Clarence King&apos;s report. I had the honor of presenting a large number of thin sections of our traps at the Washington meeting, for the inspection of the mem¬bers, with the aid of a table microscope belonging to the Smithsonian Institution. Here I propose to project these sections upon the

Jan 1, 1877

By A. E. Lee

THE Blackwell Zinc Co., Inc., a subsidiary of the American Metal Co., Ltd., operates a horizontal retort zinc smelter at Blackwell, Okla. The plant has 14 furnace blocks of 800 retorts each, fired with natural gas on a 48 hr cycle. Over 13,000 tons of zinc-bearing material, chiefly sulphide flotation concentrates, are treated monthly to produce slab zinc and high lead-cadmium fume. In 1942 a program of rebuilding and modernizing the smelter was started. By 1947 furnace smelting capacity had been increased to a point where roasting and sintering facilities were inadequate, and it was necessary to purchase oxidized materials to supplement sinter production. The seven 210 ft Ropp roasters and three 42 in. x 44 ft Dwight-Lloyd machines then in use had been in service at least 20 years and were in need of major rebuilding. Thus it was entirely practical to consider all new equipment and a change of method rather than rebuilding and repairing obsolete units. A study of the problem indicated that roasting as such could be eliminated and roasting and sintering accomplished in one step by a modification of the Robson process,&apos; which had been used since the early 1930&apos;s by the National Smelting Co., Ltd., at their plants at Avonmouth, England, and Swansea Vale, South Wales. Francis P. Sinn, General Manager, Zinc Smelting Operations, The American Metal Co., Ltd., who was familiar with the practice in England, suggested the use of one large machine for the entire operation from concentrate to sinter. One step sintering appeared to best meet Blackwell&apos;s plant requirements and indicated substantial savings in labor, gas, coal, and repair costs. Choice of Machine Size The sinter machine size was set at 12x168 ft for a rated capacity of 540 tons per day. This tonnage, produced on a five day week, would meet the seven day requirements of the 14 furnace blocks. The one large machine was quoted at a lower cost than two or more 6 ft wide machines of similar total capacity. Further, the larger machine could be housed in a smaller structure and only one set of equipment for charge preparation and delivery and for disposal of sinter cake was needed. One machine on a five day week made possible a concentration of the skilled operating personnel and required less men than a plant including two or more machines and related equipment circuits. Fewer units of equipment meant less maintenance, and the two down days weekly allowed ample time to repair and, if necessary, to make up lost production. Experience had indicated better sintering quality and rates with larger masses of material, not only on wider machines, but also in deeper beds. The ratio of windbox perimeter to area for the 12x168 ft machine is 0.179, compared to 0.353 for a 6x102 ft machine and 0.617 for a 42 in. x 44 ft machine. This meant less air leakage with resulting fan power savings and less spoilage of charge along the pallet sides. Performance Initial operation of the new sinter plant was made in November 1951 and regular production attained late in December. The average product sinter output during 1952 and the first half of 1953 has been 18.2 tons per hr. The average for one month has been as high as 22.4 tons per hr. Considerable experimenting with varied operating conditions accounts in part for the below capacity — 24 tons per hr — average output, and work to further improve production rate continues. A typical sinter analyses is 66.0 pct Zn, 0.3 pct Pb, 0.1 pct Cd, 0.3 pct S, 8.0 pct Fe, 2.0 pct SiO,, 0.8 pct CaO, and 0.2 pct MgO. Use of this material has made possible increases in furnace burden and improved furnace operation over the former practice using sinter made from Ropp roasted concentrates. Better lead and cadmium elimination in sintering has permitted the furnace production of slab zinc lower in lead and cadmium. Anticipated economies of operation have largely been gained. The sinter plant is operated by seven men per 8 hr shift — one head operator, three equipment operators and three sweepers — plus one oiler on day shift only. While it has been necessary at times to operate seven days a week to produce the required sinter tonnage, the five day work week usually has been adequate. Consumption of natural gas for sinter bed ignition is 200,000 to 300,000 cu ft per day. Green Ore Sintering Practice The 30 to 31 pct sulphur content of the —200 mesh zinc concentrates is the fuel used to sinter the charge, no coal addition being required. In the feed to the machine, sufficient concentrates are added to crushed return sinter fines containing 0.3 to 0.5 pct sulphur to produce a charge averaging 5.0 to 6.5 pct sulphur. Since the return sinter used in Blackwell&apos;s practice is varied from — 1/2 to — 1/8 in., the actual sintering mixture of fine sinter and concentrates is somewhat higher in sulphur. The coarser sinter particles are too large to resinter and merely aid porosity in the sinter bed. The ratio of concentrates to return sinter in the charge ranges from about 1:4 to 1:5.5. Variations are based on the appearance of pried up bed sections, bed exit gas temperature trends, windbox suctions, and return sinter size. Sufficient sulphur must be used to obtain fritting of the charge into a soft sinter cake and to aid in the elimination of lead and cadmium. Excessive feed sulphur will result in partial slagging of the cake impairing porosity and prolonging sintering time.

Jan 1, 1954

ONE of the features of the annual meeting was a round table conference on carbon in pig iron, on Feb. 16. This was presided over by R. H. Sweetser, and the discussion, which was so interesting as to require holding an additional session in the after-noon, ranged over such a wide field that only a brief outline of it will be attempted here. The full discus-sion together with the papers will be printed later. The first paper was one on the need for research in foundry pig iron (1648-C) by Richard Moldenke, who pointed out the trend in present practice of attaining low cost in pig iron production by hotter blast, addi-tion of. scrap to the blast furnace, and. the enormous increase in the output per furnace day. He pointed out that remelting processes are oxidizing processes, to some degree at least, and the metal cannot be given the deoxidizing finish which is characteristic of the steel-making process. The trend today is toward specifying total carbon content in foundry pig irons, and since the carbon content depends on a variety of factors, he suggested that the blast-furnace men and the foundry men study the question and agree on a minimum of total carbon for the given silicon ranges. The discussion of this paper was participated in by E. J. Lowry, Robert Jones, T. L. Joseph,. R. H. Sweet-ser, J. G. Ferguson, W. B. Coleman, E. P. Ross and D. J. Demorest and ranged from a comparison of the total carbon used in making a ton of pig iron in charcoal practice versus coke practice to a discussion of the bad effects observable from the use of scrap This paper was followed by one on carbon character-istics of copper-bearing pig iron by W.. B. Coleman. In view of the belief in many foundries that copper-bear-ing pig iron made trouble in the foundry, experiments were made by adding copper in various amounts up to 1 per cent and with the cooperation of the Robesonia Iron Co. a large number of tests were made over a run of foundry iron. The final conclusion was that the ad-dition of less than 1 per cent metallic copper did not seem to alter the physical properties and that a blast furnace using copper-bearing ore can produce pig iron suitable for making small castings, showing low-Brinell hardness test, good transverse and deflection tests, and high-total carbon.

Jan 3, 1927