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By Arthur F. Taggart

In 1900, Elmore found that if an acidulated pulp was stirred up with an oil which was relatively insoluble in and lighter than water, and the mixture was allowed to stratify, much of the sulfide would be found hanging to the lower surface of the floating body of oil and could be skimmed off or overflowed with it. The action of the flotation agent here is twofold, first to select the sulfide from the gangue—what today is called collection—and second, to buoy the collected sulfide away from the gangue. The action in collecting is illustrated by Fig. 1: which contrasts the behavior of drops of oil brought, under water, to the surfaces of gangue and sulfide particles, respectively. The oil displaces water from the surface of the sulfide; the water displaces oil from the gangue surface. If, instead of considering the solid particles the fixed parts of the system of oil, water and solids. we consider the oil and water fixed and the solids presented to the surface of contact, the condition will be as shown in Fig. 2; the sulfide tends to be drawn into the interface and the gangue to be excluded. The sulfide particles are held in the oil-water surface by the tension of this surface. The buoyant effect is supplied by the oil droplets in bringing the sulfides to the water surface, but not in holding them there. Gas as Buoyant Medium of Flotation In 1906 Sulman. Picard and Ballot discovered a practical and substantially fool-proof method of doing what Everson, in 1886, and Fro-nlcnt. DeBavay Bessel and Elmore had been doing in the intervening years, viz.: using gas in place of oil as the buoyant medium for flotation, but retaining oil as the agent. To all of these inventors "oil," with no qualification as to its kind and no true understanding of its function, was the important thing. Hut they placed on the oil an additional burden viz.: froth-making, and it soon became apparent that not all oils were suitable for the dual purpose. As a matter of fact, it is probable that each of these inventors knew only one suitable oil at the time he wrote his patent, but used the generic term in the patent with the usual idea

Jan 1, 1928

By Shun-ichi Satoh

THE electric arc welding of cast iron has been studied by Braune, Lamberton, Schimpke, Kenyon, Gale Manufacturing Co., Wedemeyer, Candy, Neese, Miller, Carter, American Welding Society, Namack, Lebrun, Achenbach, Jansson, Kochendörffer and others.1 The writer of this paper has been able to obtain a series of cast irons, from gray to white, without using cast-iron electrodes but by coating on wrought-iron bars mixtures of carborundum (SiC) and graphite (C). In this work, he has found the curious phenomenon of barium- carbonate.

Jan 1, 1929

By Albert S. Trube

The purpose of this paper is to clarify the definition of compressibility and to present a uniform basis upon which instantaneous compressibilities of liquids and gases can be compared. The equations gaverning the instantaneous compressibilities of imperfect gases are derived and the concept of pseudo-reduced compressibility is introduced. Part of the data presented by Brown, Katz et a1 on compressibility factors for natural gases has been rearranged. A graph of pseudo-reduced compressibility vs pseudo-reduced pressure for various pseudo-reduced temperatures is presented. The need for additional work in relating the compressibilities of liquids and gases is discussed. This information should be of value to reservoir engineers in making non-steady state performance calculations in gas reservoirs. It should be of further use irz pointing the direction for additional research in the nature of liquid and gas compressibilities. INTRODUCTION With the increasing use of steady and non-steady state well and reservoir data, there is a corresponding increase in the importance of the various factors entering into such calculations. Increasing emphasis is being placed on the necessity for obtaining reasonably accurate estimates of the physical properties of the reservoir fluids well in advance of the more accurate laboratory data. One such factor is the isothermal coefficient of expansion of the media which are transmitting and attenuating the non-steady state pressure waves. The average isothermal coefficient of expansion, or "compressibility" is a complex function controlled by the physical properties of the formation and the fluids contained therein. The isothermal expansion coefficients for reservoir gases are usually quite variable, in many cases being highly-pressure sensitive. The coefficients for reservoir liquids tend to be pressure sensitive, but not nearly so much as reservoir gases. The coefficients for solids, usually expressed in terms of a "modulus of elasticity" are relatively insensitive to pressure variations within their elastic limits. For this reason, and also because many previous applications have been limited to rel- atively small pressure ranges, there has been a tendency to ignore the variable nature of isothermal expansion coefficients and treat them as constants. Also, the term "compressibility" by which these coefficients are generally designated is commonly confused with a similar term, z, used to define the deviation of an imperfect natural gas from the perfect gas laws. A clear distinction should be made at the outset between the term "compressibility", which is an isothermal coefficient of expansion of a substance, and the term "compressibility factor", z, which refers to the deviation of a gas from the perfect gas laws. Although the scope of this paper is limited to the compressibility of single phase natural gases, it is definitely related to the problem of accurately estimating the compressibilities of single phase hydrocarbon reservoir liquids, which will form the basis of a future presentation. BASIC PRINCIPLES The coefficient of isothermal compressibility of a substance, c, is usually determined from pressure-volume or pressure-length -measurements depending upon whether the substance is single phase gas, liquid, or solid. A convenient method for making such estimates for a finite change in pressure and volume at constant temperature is to use the well known equation V1-V2/V1 (p2 - p1) .....(1) Eq. 1 is negative because the volume of a confined substance decreases as the pressure is increased. In this case V1 > V2 and p2 > p1. This equation is useful in approximating the compressibilities of single phase gases and liquids undergoing small pressure changes. It is evident, however, that this equation is almost identical with the determination of Young's modulus of elasticity for solids. If the assumption is made that change in length is directly proportional to change in volume, as would very nearly be the case for a steel rod in tension within its elastic limit, then E5=-L1 (p2 - p1)/L1 - L2 .......(2) in which E. is the isothermal expansion coefficient, or Young's modulus of elasticity, for a solid. And further, for this special case L1 (p2 - p1)/L1 - L2 .......(3)

Jan 1, 1958

By F. E. Calkins

THE following presentation of the more important accumulated facts and probabilities involved in copper ore deposition is based on my experience in examination work and study of the extensive litera-ture of the subject; to make personal mention of all sources of information would require the naming of a small army of able geologists and other investigators who have contributed to, building up the science. I have tried to present the salient features of the subject in logical order and condensed form, and to point out the relative importance of processes involved. Doubt-less many geologists could suggest some changes and many additions. ORIGINAL SOURCE The original source of all copper was in the earth's interior; it has been brought to the outer part of the earth, within reach of man, in three ways: (1) By intrusions and flows of basic igneous rocks containing copper in minute quantities, presumably as silicate or sulfide. No orebodies have been formed by this method. (2) As segregations within intrusive igneous rocks, the copper minerals having solidified at the same time as the rock itself. The few deposits known to have been formed in this manner have been of little or no importance. The oft quoted Sudbury nickel-copper deposits are now known to belong to the class following. (3) By gaseous or liquid aqueous emanations from ,large deep-seated masses of intrusive molten rock. These emanations, or mineral solutions, ascended through zones of connected openings in the earth's crust and dropped their load at points far above their source. Deposits formed in this manner were the primary source of nearly all, if not all, of the world's copper production.

Jan 10, 1923

By Ferdinand S. Ruttmann

There is now in use at the mines of the Chateaugay Ore and Iron Co., at Lyon Mountain, New York, an ore-concentrating machine or jig, which, in view of the increasing attention given to the subject of concentrating lean ores of iron, seems worthy of notice. This Conkling Jig, as it is called, is not entirely unknown, having been used at several places with more or less success; but as yet, I believe, no drawings of it or records of its work have found a place in print. Although the jig will be found to be merely an adaptation of old forms, there are several points which deserve attention, particularly the method of central discharge, of freeing the bearings from grit, and the rotation of the sieve or screen. The ore-body at Lyon Mountain consists of a bed of rather compact, granular magnetite, occurring in a gueiss formation. The side walls of the ore-body are not sharply defined, the ore 011 either side becoming gradually poorer as the distance from the central point of the body increases. It is this lean ore, which, before the introduction of the jigs, was thrown away as waste, that is now concentrated. The material treated conseqnently consists of magnetite, intermixed with the component parts of gneiss, viz. quartz, felspar, hornblende, and mica. Grains of trap also form part of this material. These come from dykes of trap, which cross the ore-body at intervals. The ore which is to be concentrated usually contains from 30 to 40 per cent. of metallic iron. It is first crushed to the size of two inches, or less, by two large Blake crushers. The material from these crushers passes by a shute lined with screens, having holes 2 inches in diameter, to a second set of four crushers, set so as to close to one inch. The product from this set of crushers, together with that which passes through the screens in the shute, is then taken by an elevator to the top of the mill, and passed through a revolving screen, perforated with ) inch holes. The ore which passes through the screen goes to the jig-hoppers ; that which passes over goes to a third

Jan 1, 1888

Jan 1, 1922

Jan 1, 1922

By S. J. McCarroll

THE Three Kids mine, some six miles east of Henderson, Nev., is in a typical southwest desert area, with high dry summer heat and cool to cold winter seasons. The manganese deposit was located during World War I.1 During this period 15,000 to 20,000 tons of ore assaying up to 41 pct manganese were shipped. Interest in the deposit was not revived until the middle thirties, when experiments on the ore were initiated. Test work indicated possible recovery of only 70 pct by flotation, but in 1941 additional work was done at the Boulder City pilot plant of the U. S. Bureau of Mines and also by M. A. Hanna Co. As a result, the Manganese Ore Co. was formed and a plant utilizing the SO, process was constructed. Numerous operation difficulties ensued, and the plant was closed when the manganese situation in the country eased.

Jan 3, 1954

By C. S. Trewin

Zinc, in its wrought form, is produced commercially in rolled strip, sheet, wire, rod and tubing. Wire has been made periodically, but due to the fact that slight drafts are necessary, the cost of production is greater than for the more common non-ferrous metals which are made into wire. Notwithstanding the cost, zinc wire has certain special uses for which it is particularly adaptable. Rod has been made both by rolling and extrusion; the product, however, has not indicated great commercial value. Tubing has been made from strip from time to time by forming a strip around a mandrel and either electrically or gas-welding a longitudinal joint. Recently a tube manufacturer has succeeded in making a fair quantity of this material. Its commercial adaptability is still to be dctcrmined but anyone who desires it can obtain quantities of the smaller sizes. Inasmuch as strip and sheet are commercially the most important, this paper will be devoted to these products. In the broader sense, zinc is not alloyed. That is, there are no combinations comparable to the various copper, aluminum and nickel alloys. It has been recognized for some time that the lead and cadmium occurring with commercial zinc have some effect on its properties and such alloys as may be said to exist are those made from zincs containing varying amounts of lead and cadmium with a relatively low iron content. The foreign rolled zinc will analyze higher in lead than the domestic grades. A representative foreign analysis will run 1.1 per cent. lead, 0.07 per cent. cadmium and 0.02 per cent. iron. The American grades vary from zinc approximating high grade and analyzing 0.08 per cent, lead, 0.002 per cent. cadmium and 0.015 per cent. iron, to the lower grades in which the lead will vary from 0.3 to 1.0 per cent., cadmium from 0.10 to 0.5 per cent. and the iron in the neighborhood of 0.02 percent. Rolled Zinc Rolled zinc is produced in both the strip (or ribbon) form in which the product is rolled from a single bar in one continuous direction, or sheet in

By S. F. Emmons

The first paper which appears in the published Transactions of our Institute is that read by our respected Secretary at its first meeting in Wilkes-Barre in May, 1871. It is entitled " The Geographical Distribution of Mining Districts in the United States," and presents a brief but masterly review of what was known of the distribution of our deposits of useful minerals, particularly the metals, not only from a geographical but from a geological stand-point. At the request of Dr. Raymond I agreed, somewhat hastily, perhaps, to write for this occasion a brief sketch of the geological distribution of the deposits of the useful metals in this country, in the light of the increased knowledge of the present day. In the time given no personal investigation was possible, and as it was therefore out of the question to attempt to make anything that could be considered an original contribution to the history of our ore-deposits, I have been obliged to limit myself to an examination of such pub-

Jan 1, 1894

By L. S. Darken

Measurements of the electrical conductivity, the thermal electromotive force, and the deviation from stoichiometry by thermogravimetry were made on ferrous oxide (wüstite) single crystals as well as on poly-crystalline samples in the temperature range of -900" to 1330°C. In the region defined by T 2 1000°C and 1.05 5 O/Fe 5 1.10 the electrical conductivity was shown to be proportional to the sixth root of- the oxygen partial pressure and to be linearly dependent on the deviation from stoichiometry. The absolute Seebeck coefficient of single and polycrystalline wüstite was shown to be independent of temperature in the above region and a p to n transition of the Seebeck coefficient was observed at O/Fe = 1.09 in polycrystalline wüstite. Analysis of the results showed that the predominant defects in wüstite in the above region were doubly ionized cation vacancies. The analysis also ruled out the existence of complexes of the type postulated by Roth, except that below 1000°C there is some evidence of 'association of defects. Of the three oxides of iron (FeO, Fe3O4, Fe2O3) only FeO (wüstite) can exist within a wide range of the ratio O/Fe. This has been shown by several investigations of the phase diagram using for instance chemical analysis of quenched samples'-4 or thermogravimetric measurements. 5,8 Darken and Gurry's1 data for example in the temper- ature range 1100o to 1400°C show that the lowest O/Fe ratio obtainable for FeOl +. is about 1.045 and that the existence range extends to O/Fe = 1.20 at 1400oC. On the basis of detailed analysis of thermogravimetric measurements made by Vallet and Raccah6 the existence of three varieties of wüstite at elevated temperatures was suggested by these authors and by Kleman. It is well-established that wüstite has a NaCl structure with vacant cation sites.3, 8 From a neutron-diffraction study of wüstite samples quenched to room temperature Roth9 concluded that defects in wüstite are mostly complexes composed of two cation vacancies and one interstitial cation in a tetrahedral site. The atomic arrangement in the vicinity of such a defect is similar to that in magnetite, where each occupied tetrahedral site is surrounded by four vacant octahedral positions disposed at the corners of a tetrahedron, so arranged that each vacancy is shared by two tetrahedral cations. Thus there is an average of two vacancies per interstitial. Recent X-ray diffraction measurements made by Smuts10 on quenched wüstite samples confirmed the results of Roth's neutron-diffraction experiments. Roth's model of defects in FeO can be regarded as a solid solution of Fe3O4 in FeO; salmon1' used this defect model to calculate the activity of Fe3O1 in FeO at high temperature and claimed good agreement with the results obtained experimentally by Darken and Gurry.' Each missing cation in wüstite is accompanied by two trivalent cations, thus preserving charge neutrality. The "holes" which differentiate between the Fe 2+ and Fe3' states of the ions in octahedral positions can overcome the attractive field of the cation vacancies, and are then free to move through the crystal as charge carriers. A similar picture holds for COO, NiO, andMnO.l2, 13 Localization of the charge carriers in transition

Jan 1, 1968

By S. Paul Lindau

THREE years ago it was decided by the management to granulate the matte that is produced in the smelter of the St: Joseph Lead Co. at Herculaneum, Mo., thereby doing away with a large amount of labor in handling the matte and in subsequent crushing. On Mar. 1, 1915, the granulator was put in operation and up to Jan. 1, 1916, 18,735 tons had been, granulated. The four blast furnaces have a daily output of about 280 tons of pig lead and 100 tons of matte assaying about 11.0 per cent. Pb. It is expected that projected improvements in roasting methods will eliminate more sulphur from the charge, and cut down the matte-fall, to about one-half of the present figure. The blast furnaces are tapped into movable forehearths or settlers, 6 ft. by 4 ft. by 22 in., the slag overflowing into 27-cu. ft. slag cars which are hauled to the clump by electric locomotives. Previous to the adoption of granulation, the matte was tapped from the forehearths into small slag pots which were dumped after cooling. The matte cakes were broken with sledges, and transported to the crushing plant for fine crushing and screening. Here the matte was reduced to ¼ -in. size before being fed to the roaster bins.. A Wedge and a Holthoff mechanical furnace are used for preroasting before sintering on the Dwight and Lloyd machines. The matte is returned to the furnaces as an iron flux until the .gradually accumulating copper content reaches about 7 per cent., after which it is put aside to be concentrated in a small copper blast furnace, the resultant high-grade matte-being sold. When the matte does not settle readily from the slag, two settling devices are often used, the second one being a large catch-pot, which gathers any matte that may overflow from the forehearth, the slag then overflowing from the catch-pot into the slag cars. When full of matte, the catch-pot is removed, allowed to cool, and the contents broken and crushed.

Jan 10, 1916

By James K. Hallenburg

INTRODUCTION The delayed fission neutron, or DFN technique for uranium ore body analysis uses the first down-hole method for detecting uranium in place quantitatively. This technique detects the presence of and measures the amount of uranium in the formation. DFN TECHNIQUE DESCRIPTION The DFN technique depends upon inducing a fission reaction in the formation uranium with neutrons, resulting in an anomalous and quantitative return of neutrons from the uranium. Since there are no free, natural neutrons in formation, a good, low noise assessment may be made. There are several methods available for determining uranium quantity in situ. The method used by Century uses an electrical source of neutrons. This is a linear accelerator which bombards a tritium target with high velocity deuterium ions. The resulting reaction emits high energy neutrons which diffuse into the surrounding formation. They lose most of their energy until they come to thermal equilibrium with the formation. Upon encountering a fissile material, such as uranium, these thermal neutrons will react with the material. These reactions produce additional neutrons, the number of which is a function of the number of original neutrons and the amount of fissile material exposed. The particular source used, the linear accelerator, has several distinct advantages over other types of sources: 1. It can be turned off. Thus, it does not constitute a radioactive hazard when it is not in use. 2. It can be gated on in short bursts (6 to 8 microseconds). This results in measurements free of a high background of primary neutrons. 3. The output can be controlled. Thus, the neutron output can be made the same in a number of tools, easily and automatically. There are several interesting reactions which take place during the lifetime of the neutrons around the source. During the slowing down or moderating process the neutron can react with several elements. One of these is oxygen 17. This results in a background level of neutrons in any of the measurements which must be accounted for in any interpretation technique. These elements are usually uninteresting economically. The high energy neutrons will also react with uranium 238. However, the proportions of uranium 235 and 238 are nearly constant. Therefore, this reaction aids detection of uranium mineral and need not be seperated out. Upon reaching thermal energy the neutrons will react with any fissile material, uranium 235, uranium 234, and thorium 232. At present, we do not have good techniques for seperating out the reaction products of uranium 234 and thorium 232. However, uranium 234 is a small (.0055%) percentage of the uranium mineral and thorium 232 is usually not present in sedimentary deposits. When the uranium 235 reacts with thermal neutrons it breaks into two or more fragments and some neutrons. This occurs within a few microseconds after the primary neutrons have moderated and is the prompt reaction. One system uses this; the PFN or prompt fission neutron technique. We don't use this method because the neutron population is low and, therefore, the signal is small and difficult to work with, accurately. Within a few microseconds to several seconds the fission fragments also decay with the emmission of additional neutrons. Now, with a long time period available and a large neutron population we gate off the generator and measure the delayed fission neutrons after a waiting period. These neutrons can be a measure of the amount of uranium present around the probe. Thermal neutrons are detected with the DFN technique instead of capture gamma rays to avoid some of the returns from other elements than uranium. LOGGING TECHNIQUE The exact logging technique will depend, to some extent, upon the purpose of the measurement. However, the general technique is to first run the standard logs. These will include: 1. The gamma ray log for initial evaluation of the mineral body and for determining the position of the borehole within the mineral body, 2. The resistance or resistivity log for determining the formation quality, lithology, and porosity. 3. The S. P. curve for estimating the redox state and shale content, and measuring formation water salinity, 4. The hole deviation for locating the position, depth, and thickness of the mineral (and other formations), and 5. The neutron porosity curve. The neutron porosity curve is most important to the interpretation of the DFN readings. The neutrons from this tool are affected in the same way by bore hole and formation fluids as the DFN neutrons are. Therefore, we can use this curve to determine effect of the oxygen 17 in the water. Of course, this curve can be used to determine formation porosity. It can also be used to calculate formation density.

Jan 1, 1979

By H. J. Wasson, L. W. Mayer

The existing large stocks of raw materials have induced misgivings in the minds of many as to near-view prospects for a return to higher commodity price levels. Until stocks are materially reduced—and this operation will probably extend over a protracted period—a buyers' market will continue. Meanwhile the matter of production cost becomes more and more a factor of consequence to industrial management, finance and the investing public. With many commodities a general level of costs exists with which the public has been made familiar. Certain conditions surround these industries which, at the outset, determine whether there is a basis for sound commercial results. In other words, it can generally be determined in advance whether or not the cost of production is sufficiently below the normal average price to return a reasonable profit over the years. With all domestic agricultural products there are available exhaustive Government studies in the field of production costs. Such figures as the average cost of wheat, cotton, sugar, etc., are reiterated constantly. There are many products of foreign origin such as coffee, rubber, raw silk, etc., the production costs of which are to most of us matters of deep mystery. Forest products also are so diversified that few but specialists know what a thousand feet of lumber really cost at the mill, especially where remotely located. However, with respect to products of mines, production cost information has been widely disseminated. The literature is replete with such data. Here we find that without any special help from outside agencies the industry itself has given publicity to a large variety of cost figures. For example, we know, or know where we can ascertain, the cost of producing a pound of copper from Chile, Arizona or the Lake Superior district. In many cases we can secure from the company reports a vast amount of detail leading up to the cost per ton of ore and the cost per unit of the metal yield. These records are of great assistance to the mining industry as a means of estimating on new exploitations. This industry has been production-cost-minded almost from the beginning.

Jan 1, 1931

By J. H. Swartz

During 1938 and 1939, an extensive series of geophysical surveys, employing both resistivity and magnetic methods, have been carried on in the Hawaiian Islands by the Section of Geophysics of the United States Geological Survey in cooperation with the Division of Ground-Water of the Survey and the Division of Hydrography of the Territorial Government (see Fig. 1). During this time, surveys have been conducted on the islands of Oahu, Molokai, and Maui. Two distinct types of ground-water occurrence are being investigated: (1) The basal fresh-water lens floating on underlying salt water in obedience to the Ghyben-Herzberg principle (Fig. 2); and (2) perched ground-water (Fig. 3).

Jan 1, 1940

By J. L. Huiatt, G. M. Potter, R. B. Tippin

The US Bureau of Mines and Great Salt Lake Minerals and Chemical Corp. have developed a froth flotation process for concentrating potassium salts from Great Salt Lake solar evaporites containing about 6% K2O. The crude evaporites, which were predominately halite (NaCl) with smaller amounts of kainite (KCl.MgS0, 2.7Hp0) and schoenite KeS0,MgS04.6H,0), were conditioned in a saturated brine solution., thus converting nonfloatable kainite to the floatable mineral schoenite. Schoenite was then selectively floated with a medium-molecular-weight fatty acid. Continuous small-scale pilot-plant testing indicated that 80% of the potassium could be recovered from the crude evaporites in flotation concentrates assaying about 13% K2O.

Jan 1, 1976

Secretary's NOTE—on page 176,of this paper, in the fourth line of the first footnote, " 4° " should, be " 1" )'; and on page 180, at the beginning of line 23, ('lined boot" should be " unlined boot." Discussion. Frank Owen, London, Eng. (communication to the Secretary) : In his very interesting and valuable paper, Prof. Snow

Jan 1, 1900

By M. F. Trice

PYROPHYLLITE is a hydrous aluminum silicate (A12Si4O10(OH)2)1 that occurs in both the foliated and the massive forms. The foliated variety resembles talc in that it has a greasy feel, a pearly luster, perfect basal cleavage, and usually is white, although in some deposits apple green, gray, brown, russet, and nearly black specimens may be found. The massive deposits of pyrophyllite yield pearl gray to light tan aggregates, some of which are so friable that they may be crushed with the hands into a fine gritty powder. Frequently specimens of the massive variety are studded with crystals of radial structure. The mineral has a specific gravity of about 2.7 and a hardness of 1 on Mohs' scale.1 The chemical composition of commercial pyrophyllite reflects the mineralogy of the deposits, which, according to Stuckey,2 contain pyrophyllite and quartz, together with chloritoid, sericite, and a few other minerals of negligible importance. The latter, he says, "are noticed in but small quantities to the extent they might occur as accessory constituents of an igneous rock or as products of regional metamorphism or weathering. . . . Quartz is abundant everywhere except in the very best grades of pyrophyllite." Analyses of specimens from several deposits are listed in Table 1, showing that the silica content varies from 57 to 73 per cent and the alumina from 22 to 33 per cent. Oxides of iron and the alkaline metals are collectively present, with one exception, to an extent of about 1 to 1.5 per cent. SOURCES At present, North Carolina is the only commercial source of pyrophyllite, although the mineral has been found in small quantities in many parts of the world. The North Carolina deposits are in the "Carolina Slate Belt," which traverses the center of the state in a southwesterly direction. This

Jan 1, 1940

By C. S. Roberts

Four binary alloys in this system were creep tested at 300°' to 600°F. A photographic study of microstructural changes showed that the outstanding creep resistance results primarily from a potent precipitation hardening locally at grain boundaries. Twinning was correlated with the primary stage and nonbasal slip with the tertiary stage of creep. THE utility of the rare earth metals as ingredients of magnesium alloys destined for elevated temperature application has been recognized for about 15 years. A review of the early development of these alloys has been given by Leontis. 1,2 It has been only recently that a desire has arisen to understand basically their remarkable creep resistance. The present research had that object. The work of Leontis showed that the differences between the behavior of the individual magnesium-rare earth element binaries was of commercial significance. However, the variations were small compared to the overall difference in creep resistance between the group as a whole and the magnesium alloys of the Al-Zn type. It was decided to conduct this investigation with one binary system which would be representative of the magnesium-rare earth element alloy group. Cerium was chosen as the solute because of its near-middle position in the series and because of its availability in the commercially pure form. A previously published description of the creep behavior of electrolytic magnesium" serves as the background to this research. The experimental approach used in that investigation has been partially repeated here. A series of binary alloys was planned to include the following: 1—A dilute alloy which would contain the cerium almost entirely in solid solution. This would assess the solid solution effect. 2—An alloy which is nearly saturated at the selected solution heat treatment temperature, 1070°F. Here the effect of nearly maximum precip- itation would be obtained without the influence of undissolved Mg-Ce intermetallic. 3—An alloy containing slightly more cerium than is soluble at 1070°F. This would allow the investigation of the effect of a small amount of excess intermetallic. 4—A high cerium alloy in which the influence of a large volume of undissolved intermetallic may be examined. Experimental Details In order to specify compositions of the binary alloy series a knowledge of the solubility of commercially pure cerium in solid electrolytic magnesium and also of the composition of the terminal intermetallic phase was necessary. The latter has been proven to be approximately Mg,Ce by Voge14 and Haughton and Schofield.5 A series of both cast and extruded alloys were solution heat treated 24 hr at 1070°F for a solubility determination. Lineal analyses of the polished and etched microstructures were accomplished with the aid of a Hurlbut

Jan 1, 1955

By Eckley B. Coxe

SINCE our last meeting, the Institute has lost, by the death of Mr. Gowen, one of its most distinguished members. I shall only attempt in this place to give a brief account of his many accomplishments and achievements; but our records would certainly be incomplete without a recognition of the important influence which he exerted upon the mining and metallurgical industries of this country, and a testimony to his private virtues of character. Although Mr. Gowen was best known as a great lawyer and as the head of a great railway corporation, he began his career, before he was of age, as the manager of a small anthracite blast-furnace at Shamokin, Northumberland County, Pennsylvania. He left this position, to engage on his own account in the mining of anthracite coal at Mt. Laffee, near Pottsville. This proved an unprofitable business, and, after the panic of 1857, he began the study of the law. As soon as he was admitted to the bar, he at once entered upon the active practice of his profession, and soon achieved an extraordinary success. In 1869 he was made President of the Philadelphia and Reading Railroad Company, and he afterwards organized the Pliladelphia and Reading Coal and Iron Company, the largest coalmining corporation in the world. He became a member of. this Institute during the first year after its organization, and remained a member until his death. He always took a deep interest in the work, and was prompt to co-operate by all means in his power in furthering the objects of the Institute. Mr. Gowen was one of the first to recognize the great importance to both miner and consumer, of the proper utilization of the small

Jan 1, 1890