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By R. C. Edwards, Will Mitchell, T. G. Kirkland

A scrubber of new design has been invented for the beneficiation of glass and chemical sands. The machine is described and its capacity and metallurgical efficiency compared with the performance of other sand cleaning devices. THREE years ago, when the Process Research Laboratory at Allis-Chalmers Manufacturing Co. sought a remedy for the increasing cost of disposing of great quantities of spent sands from foundries, R. C. Edwards developed a continuous inclined paddle scrubber which removed a substantial amount of the charred coatings from the grains with a surprisingly small amount of degradation of the sand itself.' The satisfactory results obtained on foundry sand, using this piece of equipment in conjunction with classification, suggested that a similar procedure could probably be applied to the cleaning of other sands, such as those required by the glass and chemical industries. This paper describes the flowsheet and the results of tests performed on impure natural sands. The four materials tested were silica sands obtained from widely separated geographical areas. Three of the sands tested contained various amounts of iron oxide and the fourth an excessive amount of calcareous bonding material. The iron oxide was present predominantly in the form of grain coatings, which were scuffed by the paddle scrubber, and in all cases a product was manufactured which would meet one of the sets of specifications imposed by the glass industry.' The Edwards paddle scrubber used in these tests consists of a rubber-lined steel cylinder 18 in. in diam and 48 in. long, mounted on a frame so that its slope can be varied 5" to 35" from horizontal. This variable slope permits controlled flow of material through the machine. Rubber paddles rotate inside the cylinder and are secured to a center shaft 2 in. square, which extends through the entire length and is turned at both ends so that it can be supported by sleeve bearings centrally fixed in the end plates of the shell. At the upper or feed end it extends through the bearing on the end plate into a sheave, to which the motor drive is connected by means of Texrope transmission. The four sets of paddles mounted on the shaft, two in each set, are made of rubber belting, 1/4 in. thick, 9 in. wide, and 16 in. long. The two paddles in each set are secured on opposite sides of the square shaft, but in the same longitudinal position along the shaft axis. In other words, the two paddles in the set operate 180" apart. Each successive set is mounted 90" from the preceding one. One end of each paddle is bolted to the square shaft and the other weighted by a steel bar, lx1 1hx9 in. long, which is attached about Yz in. from the outer tip of the paddle. By centrifugal force at proper shaft speed, these weights force the paddle surface to rub smoothly against the rubber lining of the cylinder. During operation, the sand forces its way between the paddle face and the surface of the cylinder, providing the necessary abrading action as the pulp flows by gravity down the length of the cylinder. The capacity of the machine is limited by the amount and the hardness of the coating material and by the quality of product desired. The degree of scrubbing is governed by the retention time in the scrubber, which in turn may be changed by varying the feed rate, water content of the feed, and

Jan 1, 1953

By Frank A. Hill

A visitor to the Northern anthracite coal-field in 1844 wrote: " History and song have hallowed the valley of Wyoming, and everything pertaining to it seems wrapped in an atmosphere of romance." Song and history have since been almost forgotten in the rush of enterprise and business energy, while the invested capital which has built 160 colliery plants, producing last year 17,031,826 tons of coal and giving employment to 50,000 men and boys, lends an atmosphere the inspiration of which is the very sustenance of prosperity and progress. The fundamental cause of this great valley's financial strength, however, rests on the fulness of its mineral wealth. Its mountains surround and its cities are built upon anthracite coal. Its foundation, physically, financially and socially, is coal. Its geology has governed its growth and developed its greatness. In 1768, ten years, prior to the celebrated Wyoming massacre, two Connecticut Yankees, named Gore, settled near Wilkesbarre, Luzerne County, and, burning Pennsylvania anthracite in their blacksmith's forges, were the first to utilize it as a fuel. Its first use in the household was also at Wilkesbarre, where, in 1808, Judge Fell burned it in an open grate. Carbondale, Wilkesbarre, and Scranton were early recognized as the coal centers of the field.

Jan 1, 1887

By C. A. Hartnagel

The year 1944 marks the eightieth anniversary of the discovery of petroleum by drilling in New York State. It was in 1864 that a half dozen shallow wells were drilled at Limestone in Cattaraugus County, in a region that now forms the northern extension of the 82,000-acre Bradford pool. These early wells found oil, but not in paying quantities. They did, however, attract attention to the district and were a factor in the development of the still active Bradford pool of Pennsylvania and New York. During 1943, the production of petroleum in New York amounted to 5,029,000 bbl. This represents a decrease over the previous year, in which 5,421,000 bbl. was produced. The flush production for the New York fields occurred in the early eighties shortly after the discovery of oil in the Richburg pool of Allegany County. During the flush period, production was in excess of five million barrels annually. By 1887, however, the output had decreased to an amount only slightly more than two million barrels, and through the early years of the present century the annual total was often less than one million barrels. Flooding of the oil sands for increasing productioil was made legal in 1919, and in 1927 the output once more reached the two million mark. Two years later it had increased to over three million barrels. In Table r is shown production since 1935, in which year for the first time the output under flooding methods was in excess of four million barrels. From this table, it is evident that oil production in New 'I'ork is rather well stabilized, and since most of the oil is obtained by the flooding, or water-drive, method, with little or no prospect of discovery of new oil territory, rapid changes in yield from year to year are not to be expected. In thickness, the oil sands have a maximum of about 50 ft., and by means oi flooding may produce 10 to 12 thousand barrels an acre and proportional amounts for thinner sands. In some cases, floods have been developed in sands only 12 ft. thick. Under good flooding conditions a yield of 2000 bbl. an acre is about the lower limit at which oil can bc produced at the present price of $3.00 a barrel. The average cost for the physical development ol a lease, not including the cost ol the lease itself, is $5000 an acre. Since several months must intervene before the flood begins to act on the oil wells, and a year or more is required to bring thc wells to maximum daily production, it is evident that a considerable interval occurs before maximum returns are realized. Once a flood is developed and the wells

Jan 1, 1944

By C. A. Hartnagel

The year 1944 marks the eightieth anniversary of the discovery of petroleum by drilling in New York State. It was in 1864 that a half dozen shallow wells were drilled at Limestone in Cattaraugus County, in a region that now forms the northern extension of the 82,000-acre Bradford pool. These early wells found oil, but not in paying quantities. They did, however, attract attention to the district and were a factor in the development of the still active Bradford pool of Pennsylvania and New York. During 1943, the production of petroleum in New York amounted to 5,029,000 bbl. This represents a decrease over the previous year, in which 5,421,000 bbl. was produced. The flush production for the New York fields occurred in the early eighties shortly after the discovery of oil in the Richburg pool of Allegany County. During the flush period, production was in excess of five million barrels annually. By 1887, however, the output had decreased to an amount only slightly more than two million barrels, and through the early years of the present century the annual total was often less than one million barrels. Flooding of the oil sands for increasing productioil was made legal in 1919, and in 1927 the output once more reached the two million mark. Two years later it had increased to over three million barrels. In Table r is shown production since 1935, in which year for the first time the output under flooding methods was in excess of four million barrels. From this table, it is evident that oil production in New 'I'ork is rather well stabilized, and since most of the oil is obtained by the flooding, or water-drive, method, with little or no prospect of discovery of new oil territory, rapid changes in yield from year to year are not to be expected. In thickness, the oil sands have a maximum of about 50 ft., and by means oi flooding may produce 10 to 12 thousand barrels an acre and proportional amounts for thinner sands. In some cases, floods have been developed in sands only 12 ft. thick. Under good flooding conditions a yield of 2000 bbl. an acre is about the lower limit at which oil can bc produced at the present price of $3.00 a barrel. The average cost for the physical development ol a lease, not including the cost ol the lease itself, is $5000 an acre. Since several months must intervene before the flood begins to act on the oil wells, and a year or more is required to bring thc wells to maximum daily production, it is evident that a considerable interval occurs before maximum returns are realized. Once a flood is developed and the wells

Jan 1, 1944

THE following employment items are made available to AIME members on a nonprofit 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., Son 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 Geologist-Petrographer. Experienced subsurface geology and petrographic rock and mineral identification. Desires position as either geologist or petrographer. M-682. Geologist, 36, married, employed. Nine years' experience geology connected with engineering, includes planning and supervising core drilling programs, study of stratigraphy and structure, special problems, report writing. Three years' teaching experience. Desires responsible position offering opportunity for advancement with progressive concern. Will travel part time. Available reasonable notice. M-683. Mining Executive with record of accomplishment organizing and directing efficient low cost mining and ore dressing operations available for position in the United States. Broad experience engineering, mechanized mining, flotation, safety, union labor relations and preparation of reports. Married. Employed; available upon reasonable notice. M-684.

Jan 1, 1952

ARIZONA Established July 10, 1915 ROBERT W. THOMAS. Chairman ROBERT W. HUGHES, Vice-Chairman HUBERT O. WOODS. Secretary-Treasurer American Smelting & Refining CO., Hayden, Ariz. FRANK A. WARDLAW, JR., National Director THEODORE BROOKS I H. C. HENBIE THOMAS C. CHAPMAN P. D. I. HONEYMAN CARL H. COLE JOHN E. LANNING JOHN H. DAVIS ALBERT MENDELSOHN EDWARD G. DENTZER BRENT N. RICKARD MORRIS G. FOWLER F. A. WARDLAW, JR.

Jan 1, 1942

By John Dasher

Chemical processing is descended from alchemy, which developed our major lixivants. The profession might have done more if it had been less preoccupied with turning base metals into gold-a process that still hasn't been developed. Georg Agricola, over 400 years ago, gave us ten recipes for "aqua valens" to part gold and silver, and described cementation of gold and silver on base metals. His text stood for 200 years, by which time heap roasting, leaching and cementation were winning copper from pyrites at Rio Tinto and the Barba furnace was distilling mercury from the ores of Almaden.

Jan 1, 1971

By Harrison Schmidt

Since the U. S. Geological Survey published the data on the Central Mining District collected by Lindgren and Gratonl and by Paige2 much new information has been obtained by development and mapping, but none of it had been published until recently when Kniffin3 published on Fierro, Lasky4 on the Ground Hog mine, Thorne5 on Santa Rita and Landon6 filed a thesis on the Fierro-Hanover-Santa Rita area at the University of Chicago. During the years 1927-1930 much of the writer's time was spent in mapping the geology and ore deposits of this district, particularly in the area of the zinc deposits at Hanover. Some of the data collected are presented here. Previous publications have been freely drawn upon and additional data used that were generously supplied by L. M. Kniffin, Wilfred Wright and Gerald Ballmer. Thanks are due Augustus Locke, Samuel G. Lasky, Kniffin, Wright and Ballmer for suggestions and critical readings of the manuscript, and to the Empire Zinc Co. (a subsidiary of the New Jersey Zinc Co.) for the privilege of publishing material compiled largely at its expense. The relation of the Central or the Santa Rita-Hanover-Fierro district to the Silver City district is shown on Paige's geologic map in the Silver City folio.7 Granodiorite porphyry and quartz-monzonite porphyry

Jan 1, 1935

By Harrison Schmidt

Since the U. S. Geological Survey published the data on the Central Mining District collected by Lindgren and Gratonl and by Paige2 much new information has been obtained by development and mapping, but none of it had been published until recently when Kniffin3 published on Fierro, Lasky4 on the Ground Hog mine, Thorne5 on Santa Rita and Landon6 filed a thesis on the Fierro-Hanover-Santa Rita area at the University of Chicago. During the years 1927-1930 much of the writer's time was spent in mapping the geology and ore deposits of this district, particularly in the area of the zinc deposits at Hanover. Some of the data collected are presented here. Previous publications have been freely drawn upon and additional data used that were generously supplied by L. M. Kniffin, Wilfred Wright and Gerald Ballmer. Thanks are due Augustus Locke, Samuel G. Lasky, Kniffin, Wright and Ballmer for suggestions and critical readings of the manuscript, and to the Empire Zinc Co. (a subsidiary of the New Jersey Zinc Co.) for the privilege of publishing material compiled largely at its expense. The relation of the Central or the Santa Rita-Hanover-Fierro district to the Silver City district is shown on Paige's geologic map in the Silver City folio.7 Granodiorite porphyry and quartz-monzonite porphyry

Jan 1, 1935

Since the U. S. Geological Survey published the data on the Central Mining District collected by Lindgren and Gratonl and by Paige2 much new information has been obtained by development and mapping, but none of it had been published until recently when Kniffin3 published on Fierro, Lasky4 on the Ground Hog mine, Thorne5 on Santa Rita and Landon6 filed a thesis on the Fierro-Hanover-Santa Rita area at the University of Chicago. During the years 1927-1930 much of the writer's time was spent in mapping the geology and ore deposits of this district, particularly in the area of the zinc deposits at Hanover. Some of the data collected are presented here. Previous publications have been freely drawn upon and additional data used that were generously supplied by L. M. Kniffin, Wilfred Wright and Gerald Ballmer. Thanks are due Augustus Locke, Samuel G. Lasky, Kniffin, Wright and Ballmer for suggestions and critical readings of the manuscript, and to the Empire Zinc Co. (a subsidiary of the New Jersey Zinc Co.) for the privilege of publishing material compiled largely at its expense. The relation of the Central or the Santa Rita-Hanover-Fierro district to the Silver City district is shown on Paige's geologic map in the Silver City folio.7 Granodiorite porphyry and quartz-monzonite porphyry

Jan 1, 1935

By Harrison Schmidt

Since the U. S. Geological Survey published the data on the Central Mining District collected by Lindgren and Gratonl and by Paige2 much new information has been obtained by development and mapping, but none of it had been published until recently when Kniffin3 published on Fierro, Lasky4 on the Ground Hog mine, Thorne5 on Santa Rita and Landon6 filed a thesis on the Fierro-Hanover-Santa Rita area at the University of Chicago. During the years 1927-1930 much of the writer's time was spent in mapping the geology and ore deposits of this district, particularly in the area of the zinc deposits at Hanover. Some of the data collected are presented here. Previous publications have been freely drawn upon and additional data used that were generously supplied by L. M. Kniffin, Wilfred Wright and Gerald Ballmer. Thanks are due Augustus Locke, Samuel G. Lasky, Kniffin, Wright and Ballmer for suggestions and critical readings of the manuscript, and to the Empire Zinc Co. (a subsidiary of the New Jersey Zinc Co.) for the privilege of publishing material compiled largely at its expense. The relation of the Central or the Santa Rita-Hanover-Fierro district to the Silver City district is shown on Paige's geologic map in the Silver City folio.7 Granodiorite porphyry and quartz-monzonite porphyry

Jan 1, 1935

By G. H. Enzian

THE effects of phosphorus and nitrogen on the properties and behavior of low carbon steels are important considerations to both the manufacturer and the user of such material. For one thing, these two elements are the principal points of distinction between the chemical compositions of Bessemer and open-hearth grades. Further, open-hearth steels themselves may vary considerably in nitrogen content depending on the raw materials and ..practice used. In addition, appreciable amounts of rephosphorized open-hearth steels are being used at the present time in some low alloy, high strength grades and in certain other cases. For these and other reasons, it was felt desirable to obtain more complete knowledge of the effects of simultaneous small variations in phosphorus and nitrogen content on such properties of low carbon steel as tensile strength, impact toughness, sensitivity to cold work, and strain aging. A long range investigational program designed to furnish such information, was carried out, and the present paper summarizes some of the data currently obtained. General Discussion The strengthening effect of relatively small amounts of phosphorus in steel has been recognized, and to some extent utilized, for many years. A number of investigators have pointed out, from time to time, that under proper conditions of control, phosphorus can be a useful alloying element in low carbon steels.1-3 Nevertheless, in spite of the volume of data on the subject, the use of phosphorus for this purpose has always been handicapped by widespread feeling that its presence makes the steel brittle, difficult to cold work, and unreliable at low temperatures. This belief on the part of some steel users is not entirely justified in many cases, and often stems from early experience with acid Bessemer steels which have appreciably higher phosphorus (and nitrogen) contents than basic open-hearth grades. Nitrogen in steel, and its effect on properties, has also received considerable attention in the literature.4 In 1906, Braune5 ascribed the brittleness of Bessemer rails to the nitrogen content, and proposed a schedule of nitrogen limits for steels for various uses. This was one of the first papers to recommend directly the use of nitrogen content as a quality control measure, but it did not meet with much favor or support; as a matter of fact, the Jernkon-toret was rather sharply criticized for publishing the paper. In the intervening years a number of papers have been published on the subject of nitrogen in steel. As a result, it is now generally recognized that nitrogen can have an important effect on the properties and behavior of steel and that the presence of this element should be considered in any systematic study of factors affecting steel quality. In 1932, Graham6 introduced the concept that the quality of various steels could conveniently be evaluated and compared in terms of "sensitivity", which was defined as "the characteristic reaction rate of a piece of steel toward brittleness or hardness." This concept formed the basis for a broad research program into factors causing variations in the quality of commercial steels. At an early stage of this work, it became apparent that the observed effect of either phosphorus or nitrogen on the sensitivity of steel depended, in no small measure, on how much of the other of these two elements was also present. Indeed, the combined effect of phosphorus and nitrogen in steel may often be more important than the specific effect of either. With a few exceptions, it is not possible to predict accurately the effect on steel properties of a change in the amount of either phosphorus or nitrogen in the steel without also specifying the approximate amount of the other element. It seems desirable, at this point, to discuss briefly the distinction between strain-sensitivity and strain aging as used in this paper. In the early stages of its development, the work-brittleness test7 (which will be described in more detail later) was used

Jan 1, 1951

Terminology Relating to Nonmetallic Elements in Metals. BY T D YENSEN AND C H HERTY, JR (Tech Pub 555, Metals Tech, June 6100 words ) The paper gives arguments for confining the term "gases in metals" to its proper sphere and recommends the name "nonmetallic elements in metals" as a general title of the subject dealing with: (1) nonmetallic elements introduced into metals unintentionally or for various specific purposes; (2) phenomena occurring in metals caused by non¬metallic elements It also recommends a classification of the subject in which "gases in metals" occupies a definite, logical place

Jan 1, 1935

By H. E. Cline, D. F. Stein

A fine lamellar structure with interlamellar spacings ranging from 0.I to 3.7 was Woduced by high-speed directional solidification and used to study the interaction of dislocations with an array of bimetallic bound-am.es. The tensile flow properties were measured at elevated temperatures and the results interpreted in terms of an image force model. As the width of the plates decreases the strength increases according to a Hall-Petch relation, suggesting pile -ups. Considerable strengthening was also observed at elevated temperatures. In recent years composites containing a strong but brittle phase and a ductile but weak phase have been studied extensively in the search for a high-strength material with adequate ductility.' However, the strength of these composites has been limited to a volumetric average of the strengths of the component phases. In this paper we will show that a composite made by directional solidification of a Cu-Ag eutectic has strength properties that substantially exceed the strength of either of the metals in the composite, and an explanation for this increased strength will be presented. The Cu-Ag eutectic is a near ideal material to study for several reasons. The eutectic structure is made up of alternate plates of silver-rich and copper-rich phases with the same crystal structure.2'3 In addition, the mechanical and elastic properties of silver4 and copper5 are known over a wide range of temperatures and the eutectic microstructure is stable to nearly the melting point.6'7 Therefore, the properties of the eu-tectic are readily comparable to various theories involving the mechanical properties of copper and silver. The experiments consisted of producing directionally solidified Ag-Cu eutectic material, determining the structure and performing tensile tests at different temperatures and strain rates. EXPERIMENTAL A) Solidification and structure. A cylindrical ingot 2.2 cm in diam and 15 cm long was prepared from 99.999 pct pure materials and cast in argon. The ingot was placed in an alumina crucible and was direc-tionally solidified at 7 x 10"4 cm per sec in a Bridg-man apparatus in argon. Metallographic examination at both ends and along the length of the ingot showed a uniform structure that consisted of fine alternate plates of silver- and copper-rich phases. The plates were aligned parallel to the growth direction, as shown in the longitudinal section, Fig. 1, and were in small randomly oriented domains of parallel plates as viewed in a transverse section, Fig. 2. Four smaller ingots 0.175 in. in diam were solidified at speeds of 2Xlo-', 4.4 xlo-', 4.4 x 10-3, and4.4x10-4 cm per sec to produce a range of lamellar spacings. Replica electron micrographs were taken to resolve the individual plates as shown in Fig. 3. The copper-and silver-rich plates in the larger ingot were about

Jan 1, 1970

Established as a Division February 16, 1948 H Rush Spedden, Chairman Neil Plummer, Associate Chairman Stephen E Erickson, First Regional Vice-Chairman D A Dahlstrom, Second Regional Vice-Chairman Win T Marston, Secretary-Treasurer Dorr-Oliver, Inc 77 Havermeyer Lane Stamford, Connecticut

Jan 1, 1960

By Arnt Solbu, Jomar Thonstad

The reaction between CO, and aluminum in cryolite-alumina melts in contact with aluminum has been studied by passing CO2 over the melt. In unstirred melts a homogeneous reaction between dissolved metal and dissolved CO2 was observed. In stirred melts in which convection was induced by bubbling argon through the melt, the dissolved metal apparently reacted mainly with gaseous CO2. The rate of formation of CO increased slightly with increasing depth of the melt, and it did not depend on whether CO2 was passed over or bubbled through the melt. The rate of formation of CO increased with increasing area of the metal/melt interface and with the application of anodic current to the metal. It is concluded that the dissolution of metal into the melt is the rate-determining reaction. THE current efficiency in aluminum electrolysis is determined by the rate of the recombination reaction between the anode gas and the metal: 2A1 + 3CO2—A12O3 + 3CO [1] as originally stated by Pearson and waddington.1 The occurrence of this reaction in cryolite-alumina melts in contact with aluminum was first verified experimentally by Schadinger.2 Thonstad3 has shown that the reaction may proceed further to give free carbon: 2A1 + 3CO— A12O3 + 3C [2] Normally only a few percent of the CO formed undergoes such reduction. The mechanism of these reactions has not yet been clarified. Aluminum, as well as CO,, is soluble in the melt. The solubility of aluminum in cryolite-alumina melts at around 1000°C corresponds to 75 x 10- 6 mole A1 per cu cm,4 while that of CO2 is only 3 x 10-6 mole CO, per cu cm.5 Taking into account the stoichiometry of Reaction [I], the ratio between dissolved aluminum and dissolved CO2 available for the reaction in a saturated melt is about 40. Therefore, as will be shown in the following, the reaction probably mainly occurs between gaseous COa and dissolved aluminum. The dissolved aluminum presumably consists of subvalent ions of aluminum and sodium.4'6 Since the interpretation of the present results is not dependent upon the nature of this solution, the dissolved metal will be designated solely as Al+ in the following. The reaction can then be divided into four steps: A) dissolution of metal, e.g., 2A1 + Al3 — 3A1+ [3] B) diffusion of dissolved metal through a boundary layer; C) transport of dissolved metal through the bulk of the melt; D) Reaction [1]. If dissolved CO, takes part in the reaction, three additional steps embodying the dissolution and transport of CO2 must be added. schadinger2 observed, when bubbling CO2 through the melt, that the rate of formation of CO (in the following designated rfco) did not depend on the distance from the metal surface. The results also indicate that the rate of bubbling did not affect the rfco. When passing CO, over the melt, Revazyan7 found that the loss of metal did not depend on the depth of the melt above the metal or on the flow rate of CO2, and concluded that Step A is rate-determining. In an unstirred melt, however, Gjerstad and welch8 found that the rfCo decreased with increasing depth of the melt, indicating that step C was rate-determining. It thus appears that the rate control of the process depends on the experimental conditions, particularly on the convection. In the present measurements the reaction has been studied in unstirred as well as in stirred melts. EXPERIMENTAL AND RESULTS The experiments were carried out at 1000°C in a Kanthal furnace with a 10-cm uniform temperature zone (±0.l°C). The melts were made up of "super purity" aluminum (99.998 pct), hand-picked natural cryolite, and reagent-grade alumina. In experiments where alumina crucibles were used, the alumina content in the melt was close to saturation (13.5 wt pct9); otherwise it was 4 wt pct. Pure Co2 (99.85 pct) was passed over the melt, and the exit gas was analyzed for CO2 and CO by the conventional absorption method.3 From the weighed amount of CO (as CO2) the rfco was calculated as the number of moles of CO formed per min per sq cm of the surface area of the melt. The amount of carbon formed by Reaction [2] was not determined. As already indicated the rfco is much higher than the rfC, by Reaction [2]. Since the rfC probably is proportional to the rfco, the measured rfco should then the proportional to, but slightly lower than, the total rate of Reactions [I] and 121. In general the scatter of results obtained in duplicate measurements was ±5 to 10 pct, while within a given run a precision of ±3 to 5 pct was obtained. The various crucible assemblies that were used will be described below. Measurements in Unstirred Melts. When carrying out aluminum electrolysis in small alumina crucibles. Tuset10 observed that after solidification the lower part of the electrolyte was gray and contained free metal, while the upper part near the anode was white and contained no metal. One may test for the presence of free metal by treating with dilute hydrochlorid acid.

Jan 1, 1969

By A. B. Hildebrandt

P. B. Baxendell is to be complimented for an exccllent piece of work. To our knowledge there has been no previous publication of field data on the flow of oil and gas through the annulus of a well. It is certainly gratifying to see this work on annular flow confirm the previous published correlation procedure on tubing flow. It extends considerably the range under which reliable gas-lift calculations can be made. Baxendell discussed this work with us about a year ago and was kind enough to send a large scale plot of his correlation. We had been designing gas-lift installations on flow through the annulus, assuming that the original correlation of the f factor based on tubing flow' was valid as long as we stayed within the same mass velocity range on which the correlation was based. Doing this work necessitated the use of an equivalent diameter for the annular flow. The equivalent diameter is defined as area' of stream cross section wetted perimeter and for the case of an annulus is D, — D,. Substituting this in the basic equation correlating energy loss along with the area to flow required to convert the velocity, to volumetric flow rate, D (Baxendell's Eq. 7) becomes dell's expression, D,). Similarly, the D in 1.4737 X 10 (M&/D) becomes (D, + D;) for annular flow. On receipt of Baxendell's data, we. of course, recalculated it to put it into the form we were using, and to see how well it agreed with the correlation based on tubing flow. Fig. 1 shows the results, which were certainly gratifying. For low values of (D, - D,) pv, the data coincide with the data on flow through tubing, whereas at high values the data on flow through the annuli appear to be leveling off to a constant value. For very high rates of flow where the turbulence is very high, one might expect the value f to level out and become constant. A bulletin published in 1914 by the U. of Wisconsin presented results of a large number of laboratory teats in air lifting water through short lengths of 1.25-in. tubing. It was possible to correlate a random sampling of

BRANCH COUNCILS MINING BRANCH R M Foose, Chairman (Industrial Minerals) Carroll A Garner (Coal) J V Beall, Eastern Secretary A B Cunmins (Industrial Minerals) R E O'Brien, Western Secretary E D Gardner (Mining, Geology, and Geophysics) Carroll F Hardy (Coal) Philip J Shenon (Mining, Geology, and Geophysics) R E Byler (Minerals Beneficiation) A C. Callen (Mineral Industry Education) Grover J Bolt (Minerals Beneficiation) R J Lund (Mineral Economics)

Jan 1, 1951

THE following employment items are made available to AIME members on a nonprofit 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., Son 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 Engineer, 43, married. Sixteen years' experience mining. Desires permanent position mine superintendent. Broad knowledge all types underground mining and shaft sinking. Construction and milling experience. Prefer North American continent but will accept foreign. Presently located Australia but available May 1, 1953. M-706. POSITIONS OPEN Mining Engineer with broad exploration experience, young, single status, and must be in excellent physical condition, as nature of work will be under very primitive conditions. Salary about 25 pct more than applicants last salary rate plus travel expenses and living allowance. Duration until July 1953. Location, Burma. Y7498.

Jan 1, 1952

By M. Gensamer, B. Lustman

A recent paper described, by means of stereographic pole figures, the preferred orientations produced by cold-rolling low-carbon steel of automobile-body grade. It was found that the surface of the sheet exhibited a deformation texture significantly different from the texture possessed by the inside of the sheet. Efforts to produce the surface texture by buffing a sample exhibiting the normal or inside texture, using a copper lap, have not been successful. In view of the data collected by Kurdjumow and Sachs2, it was suggested that the surface texture might be the result of partial recrystallization of the normal or inside texture. The recrystallization texture of cold-rolled mild steel was studied by Goss3, but he did not use the pole-figure method, so that his conclusions were in need of verification. For these reasons the work reported in here was undertaken. It had two objectives: (1) to study the general behavior of cold-rolled mild steel on recrystallization below the critical temperature Al, and (2) to attempt experimentally a demonstaration of the genesis suggested above for the surface texture in cold-rolled steel. The material was that used by Gensamer and Mehl, cold-rolled to 97.5 per cent reduction in thickness. Fig. 1 is an X-ray pinhole photo-gram of this material, taken with the beam transmitted perpendicular to the plane of the sheet, using a molybdenum target at 35 kv. with no filter. It is typical of the inside texture, but in it the deformation texture is better developed than in the samples that showed a well developed difference between the inside and surface samples. Specimens from this sheet, which was 0.005 in. thick, were annealed for 5 min. at various temperatures in a lead bath. After about 0.0005 in. had been etched from both surfaces, X-ray photograms were prepared, using the technique described in the earlier paper1. Figs. 2 to 6 are photograms of the annealed sheet, at 566, 571, 577, 580 and 650" C. (1050' to 1202" F.), in order. Fig. 2 shows that 5 min.

Jan 1, 1937