Search Documents

A cooperative service for engineers and their employers under the direction of the American Institute of Mining and Metallurgical Engineers; American Society of Civil Engineers; American Society of Mechanical Engineers; and American Institute of Electrical Engineers, and with the cooperation in Chicago of the Western Society of Engineers, and in San Francisco of the California Section of the American Chemical Society and the Engineers Club of San Francisco. For information as to men available or positions open, address the nearest office.

Jan 1, 1923

By H. Case Willcox

AERIAL photographic surveying and mapping is not new or unknown to geologists. However, it has been utilized but little before, principally because it is only within the last few months that practical means of adapting this method to the requirements of petroleum companies have been discovered. No American aerial survey company has taken up aerial surveying and mapping as an engineering service to be offered to petroleum companies and their geologists for use in undeveloped and jungle-covered petroleum areas. This method of surveying and mapping, however, is used by the War Department, the U. S. Reclamation Service, and Geological Survey, and the corresponding Departments of the Canadian Government. ADVANTAGES OF AERIAL PHOTOGRAPHIC SURVEYING AND MAPPING The advantages of aerial photographic surveying and mapping to petroleum companies and their geologists are many. One of the most valuable is presented in the very first phase, or the exploration period. It is assumed that, when convinced that petroleum possibilities are present, a petroleum company has secured a concession of 8000 sq. mi. of unexplored area in Eastern Venezuela. The company may either have the entire area surveyed and mapped by the aerial photographic method, or send its chief field geologist up in an airplane so that he, from-an aerial reconnaissance, may reject certain portions that, for geological reasons, the company would not be interested in. He will then point out the regions that are to be surveyed and mapped. After the air-work is completed, the results are brought down, developed, and printed; then the resulting "contact prints" are given to the field geologist. They may be roughly assembled to give a general idea of the property in its entirety, or they are in shape to be examined in adjoining pairs under the stereo-scope. With this instrument, the geologist is enabled to make a minute examination of surface indications. The work of assembling and constructing a complete general or detailed map, according to the scales desired by the petroleum company and for the later office use, is continued by the aerial photographic company.

Jan 3, 1925

By AIME AIME

BUSINESS forecasting may be an inexact science, if it is a science at all, but in the opinion of the statisticians of the American Telephone & Telegraph Co. it is a valuable aid to the making of future business plans, whether it be used by a telephone system, a manufacturer whose distribution is country-wide or, one whose trade is confined to certain sections. Whatever the defects of business forecasting may be; the American Telephone & Telegraph Co: has employed it since 1921, not only for charting the probable; course of telephone traffic over long-distance lines, but' to determine the needs for new plant and equipment: caused by shifting tides in business or increases in population or general industrial expansion.

Jan 1, 1929

By S. E. Bronisz, R. E. Tate

s-plutonium samples possessing a strong growth texture have been produced by allowing them to transform under pressure from p to a. A fiber texture with [010] parallel to the pressure axis results. The textured samples are expected to be useful in determining the effects of crystallographic orientation on the physical properties of a plutonium, and initial results of measurements of resistivity and mechanical properties are described. THE crystal structure of a plutonium1 is mono-clinic, P21/m, and many of the metal's properties should reflect the crystallographic anisotropy. Unfortunately, it has not yet been possible to grow useful sizes of single crystals of a plutonium. Therefore, few of plutonium's orientation-sensitive properties have been determined as a function of crystallographic orientation. One way to gain information about at least some of the orientation-dependent properties is to study a highly textured sample. Such samples have been produced by cold rolling a plutonium,2 but they are necessarily very small in one dimension. We have now successfully used two other techniques to produce highly textured samples, not limited to small thicknesses. METHODS OF PRODUCING PREFERRED ORIENTATION The texture is produced by causing the plutonium to transform from ß to a while under pressure. It was observed by Gardner3 that applying a compres-sive load during the transformation resulted in the formation of columnar grains of a plutonium, and Cramer4 observed a similar structure in some diffusion couples rolled in the P phase. Neither of these workers, however, investigated the subject beyond these observations. The more flexible of the two methods developed is that of compressive loading. The technique is to enclose a sample of plutonium in a die assembly before applying the load. It is possible, of course, to dispense with the die and simply press the sample between two platens. In this case, however, the unrestrained sample deforms during the pressing, making it difficult to maintain the load and to control the final sample thickness. This compressive loading technique has been used on specimens ranging from 1/4 to 3 in. diameter, with height-to-diameter ratios ranging from 5 : l to 1:6. The procedure begins with loading the sample, a right cylinder of a plutonium, into the pressing die. Plastic deformation of the sample while it is being pressed is minimized by machining the sample so that its diameter is nearly the same as that of the die barrel. Then the loaded die assembly is placed in a vacuum pressing can that fits on a hydraulic press. After a vacuum is achieved the die assembly is heated to 180°C and equilibrated. The load is then applied and the specimen and die are allowed to cool to about 40° to 50°C before the pressure is removed. The resulting sample is composed of rod-shaped a -plutonium grains, the rod axes being parallel to the cylinder axis and the pressing direction. Photomicrographs of the oriented structure are shown in Fig. 1. Although most of the specimen is composed of grains whose rod axes are parallel to the cylinder axis, a thin, peripheral layer consists of rod-shaped grains whose rod axes are perpendicular to the cylinder axis. Presumably, the highly plastic nature of p plutonium leads to approximately hydrostatic conditions during the initial stages of the P — a transformation under pressure. At this time, the grains in the peripheral layer would have grown parallel to the local force direction. During the latter stages of the transformation, the accompanying volume contraction would have eliminated the radial forces, leaving only the axial force and resulting in the growth of the observed structure. The growth texture did not form without the application of pressure. Attempts were made to produce the texture by repeating the standard temperature cycle without

Jan 1, 1965

CONTENTS PAGE ANDERSON, ARVID E., and CAMERON, FRANK K.-Recovery of Copper by Leaching, Ohio Copper Co. of Utah. Discussed by Thomas B. Brighton, H. C. Goodrich, Arvid E. Anderson, Thos. P. Billings, Frank K. Cameron 2 BEESON, J. J.-Mining Districts and Their Relation to Structural Geology. Discussed by Charles Keyes, Chas. A. Porter 4 DOBBEL, CHAS. A.-Deep-hole Prospecting at the Chief Consolidated Mines. Discussed by G. W. Crane 10 CRANE, G. W.-Notes on the Geology of East Tintic. Discussed by G. W. Crane, H. E. Havernor, N. O. Lawton 11 SACKETT, B. L., BARDWELL, CARLOS, JACOBSON, SIMON, and JENSEN, N. H. Lead Smelting in Utah. Discussed by D. W. Jessup, B. L. Sackett, E. H. Laws 13 BARDWELL, E. S., and MILLER, Roy H.-Pulverized Coal as Fuel for Copper Refining Furnaces. Discussed by L. D. Anderson, E. S. Bardwell, C. P. Crawford 15 WIGTON, G. H.-The Chief Consolidated Volatilization Process and Mill. Discussed by Thomas Varley, S. G. Olmstead, V. O. Lawton, O. C. Ralston.... 16 JESSUP, D. W.-Evolution in the Preparation of Ores for Lead Blast Furnaces. Discussed by W. Spencer Reid, D. W. Jessup, Carlos Bardwell 19 ALLEN, H. P., and MADGE, WM. C.-Chloridizing Mill of the Standard Reduction Co. Discussed by Thomas Varley, H. R. Hanley, H. P. Allen, George H. Dern 20 TUCKER, E. L., and HEAD, R. E.-Effect of Cyanogen Compounds on Floatability of Pure Sulfide Minerals. Discussed by Blarney Stevens 24 Mix, B. E., and BARKER, L. M.-Method of Unloading Ores and Coarse-crushing Practice at Magna Plant of Utah Copper Co. Discussed by W. C. Madge,B. E. Mix 25 KEIGLEY, C. T.-The New Byproduct Coke Plant of the Columbia Steel Corporation. Discussed by W. M. Grant, C. T. Keigley, A. C. Feilder 25 JACKSON, P. W.-Blast Furnace Plant of the Columbia Steel Corporation. Discussed by W. R. Phibbs, H. M. Henton 26 OLDRIGHT, G. L., KEYES, H. E., and WARTMAN, F. S.-Production of Ferric Sulfate and Sulfuric Acid from Roaster Gas. Discussed by G. D. Van Arsdale William E. Greenawalt, G. L. Oldright 27 MAZANY, M. S.-Braden Copper Company Caletones Smelter. Discussed by A. B. Young, G. L. Oldright 36 HARRINGTON, D.-Safety Methods in Utah Coal Mines. Discussed by Edward K. Judd, Otto Herres, Benedict Shubart, A. C. Watts, D. Harrington 36

Jan 12, 1925

By Daniel T. O’Brian

Mineral exploration activities are benefiting from new interpretive techniques which have become economically practical with computers. Government agencies, educational institutions, and industry have each contributed research and development efforts for improving the mathematical analysis and graphical display of exploration data, resulting in operational aids not foreseeable a decade ago. Progress has been worldwide and is expanding rapidly. Books 1-10 are supplementing the periodic literature, at least one abstracting service is now active, 11 and an association has recently been formed to encourage and publicize advances in this field. 12 With the diversity of applications, only partial coverage of the subject can be made at any single symposium. Four of the six papers in this section report on the current state-of-the-art in selected areas of interest: graphics, time-sharing, mathematics, and economic analysis. The remaining two papers are descriptions of advanced statistical techniques for gaining additional information during exploration, and illustrate methods which will become more commonly applied in the future. "Computer Graphics: A New Tool for Exploration and Mining" describes the use of a computer and accessory equipment as an information retrieval device, graphically merging and displaying pertinent information for visual inspection and interpretation. This is a rapid means of studying information which has been pre-stored in a form accessible to the computer. Time-sharing is a means of achieving a comparable rapid response when calculations are being performed. The paper, "Some Applications of Time-Sharing in Mining Geophysics," describes the experience of one company using a time-sharing facility for geophysical computations. Another paper on this subject, stressing mining applications, has recently been published. 13

Jan 1, 1969

By Robert Glass Cleland

[Clarence F. Birdseye 1885-1891 William E. Dodge 1885-1903 James Douglas 1885-1917 D. Willis James 1885-1907]

Jan 1, 1952

By P. H. Royster, T. L. Joseph

In a study of the blast-furnace process, the Bureau of Mines has made many experiments for the purpose of determining the exact nature of the combustion of coke in the neighborhood of the tuyeres. Two papers1 presented at a meeting of this Institute discussed somewhat the practical aspects of coke combustibility in its relation to the operation of the blast furnace. In a later paper,2 Sherman and Kinney discussed the possible effect of variations in the combustibility of cokes on the furnace operation, and find that the "reoxidation theory" of Koppers and the "heat concentration theory" of Brassert³ are insuffcient to explain the variation in the conduct of different cokes that has been observed by furnace operators. In their report to the D-5 Committee of the American Society for Testing Materials, with which the Bureau of Mines has been cooperating, Perrott and Fieldner4 seem to agree with Sherman and Kinney that, for practical purposes, the nature of the combustion of coke at the tuyeres of any furnace is constant and is affected neither by the physical properties of the coke nor by the nature of the furnace operation. They omit as unimportant any tests on the combustibility of coke from their proposed methods for standard tests on coke. In the last two papers, it is pointed out that performance tests, in which all other factors except coke quality are kept constant, are to be desired and

Jan 1, 1924

By R. F. Miller, R. F. Campbell

Sixteen steels containing different combinations of chromium and molybdenum, in amounts up to 5 per cent of each element, were examined for microstructure and hardness after air cooling and after furnace cooling from suitable austenitizing temper- atures. Diagrams summarizing the structnres and hadness resulting from these two cooling rates are presented (Figs. 3, 4, 7).t Data were also obtained on the influence of these two elements, individually and in combination, on the depth of decarburiza-tion observed after furnace cooling (Fig. 8). Composition of Material The chemical composition of the steels investigated is given in Table I. The plain carbon steel was made in a 2 5-ton Heroult electric-are furnace, while the alloy steels were made in a 4.5-ton Ajax-Northrup elec- tric induction furnace. The cast ingots were hot-rolled to 1.75-in. bars. Air-cooled Series The I.75-in. bars were forged to flat plates, 0.25 in. thick, from which specimens 0.5 in. wide by 2 in. long were cut. The specimens were pretreated to improve their homogeneity by heating to 1830°F. (I000°C.) for 20 min. and oil-quenching. They were then reheated to 1740°F. (950°C.) for one hour and air-cooled, after

Jan 1, 1942

By R. F. Campbell, R. F. Miller

Sixteen steels containing different combinations of chromium and molybdenum, in amounts up to 5 per cent of each element, were examined for microstructure and hardness after air cooling and after furnace cooling from suitable austenitizing temper- atures. Diagrams summarizing the structnres and hadness resulting from these two cooling rates are presented (Figs. 3, 4, 7).t Data were also obtained on the influence of these two elements, individually and in combination, on the depth of decarburiza-tion observed after furnace cooling (Fig. 8). Composition of Material The chemical composition of the steels investigated is given in Table I. The plain carbon steel was made in a 2 5-ton Heroult electric-are furnace, while the alloy steels were made in a 4.5-ton Ajax-Northrup elec- tric induction furnace. The cast ingots were hot-rolled to 1.75-in. bars. Air-cooled Series The I.75-in. bars were forged to flat plates, 0.25 in. thick, from which specimens 0.5 in. wide by 2 in. long were cut. The specimens were pretreated to improve their homogeneity by heating to 1830°F. (I000°C.) for 20 min. and oil-quenching. They were then reheated to 1740°F. (950°C.) for one hour and air-cooled, after

Jan 1, 1942

By R. F. Campbell, R. F. Miller

SIXTEEN steels containing different combinations of chromium and molybdenum, in amounts up to 5 per cent of each element, were examined for microstructure and hardness after air cooling and after furnace cooling from suitable austenitizing temper- [ ] atures. Diagrams summarizing the structures and hardness resulting from these two cooling rates are presented (Figs. 3, 4, 7).† Data were also obtained on the influence of these two elements, individually and in combination, on the depth 0f decarburization observed after furnace cooling (Fig. 8). COMPOSITION OF MATERIAL The chemical composition of the steels investigated is given in Table I. The plain carbon steel was made in a 25-ton Heroult electric-arc furnace, while the alloy steels were made in a 4.5-ton Ajax-Northrup elec- [ ] tric induction furnace. The cast ingots were hot-rolled to I.75-in. bars. AIR-COOLED SERIES The I.75-in. bars were forged to flat plates, 0.25 in. thick, from which specimens 0.5 in. wide by 2 in. long were cut. The specimens were pretreated to improve their homogeneity by heating to I830°F. (1000°C.) for 20 min. and oil quenching. They were then reheated to I740°F. (950°C.) for one hour and air-cooled, after

Jan 1, 1941

By E. J. KENNEDY

FEBRUARY 15-18 will be the outstanding dates of the month for members of the A. I. M. E., for then the 141st Meeting of the Institute is to be held in the Engineering Societies Building, at New York. What with 41 technical sessions, the Annual Business Meeting at 4 o'clock Tuesday afternoon,, two sessions of the Section and Division delegates, minor committee meetings, and the many luncheons and dinners, the Dinner-Smoker, Informal Dance, President's Reception and the Dinner-Dance, the opportunity will be limited to do- more-than cast sheep's eyes at New York's other multitudinous attrac¬tions until the meeting is over. The technical program is diverse but well organized. The sessions are almost equally divided among the four days, with ten on Monday, Tuesday, and Wednesday, and 11 on Thursday. The meeting opens Monday morning with registration. Be sure to attend to this detail. Failure to do so may have its repercussions at the meeting and throughout the year.

Jan 1, 1932

By C. A. Hansen

ROASTING FERRUGINOUS ZINC-SULFIDE ORES IN 1912, Mr. J. B. Ideating was developing an electrolytic-zinc process for application to the ores of the Bully Hill mines of the General Electric Co. These ores consist of blende and pyrite so finely crystallized and so intimately mixed that no mechanical separation of the individual minerals had been found possible. The ore was reduced to about 60 mesh and roasted in a hand-rabbled reverberatory furnace preparatory to leaching with sulfuric acid. The extractions obtained were quite irregular, varying from a minimum of about 70 per cent. to a maximum of about 90 per cent. This irregularity led to the construction of a small electrically heated roasting furnace, and to the study of roasting under definitely controllable conditions. From time to time, these studies have been extended to other ores. Several commercial-plant operators profess to have gained useful information from the results of these studies and it is hoped that their usefulness may be extended by this publication. EXPERIMENTAL ELECTRIC ROASTING FURNACE The furnace used for experimental work is shown in Fig. 1. One fire-clay sagger, or pot, was set within another and the space between the two filled with Silox heat insulation. The hearth is a cast-iron plate with an imbedded ribbon of nichrome wire; this wire heater is connected to a potential regulator, which permits a very close voltage control. A mechanically driven arm is fitted with rabble blades so arranged that a uniformly thick ore bed may be maintained indefinitely. This arm is usually driven at about one revolution per minute but its speed of rotation can be varied as desired. Compressed air is led into the furnace through a meter, and it was found necessary to preheat the air in order to secure the definitely isothermal conditions sought.

Jan 8, 1919

By N. A. D. Parlee

The diffusion rate of hydrogen in liquid iron has been measured by a gas-liquid metal diffusion cell technique. The diffusion cell was formed by immersing an alumina tube containing hydrogen gas at 1 atm in a bath of stagnant liquid iron. The change in the composition of the melt in the cell was determined by measuring the rate of absorption of the gas in the cell. The appropriate solution to Fick's second law was used to examine the data and calculate diffusivi-ties. The absorption of hydrogen in stagnant pure liquid iron has been found to be diffusion-controlled. The results show that the chemical diffusion coefficient, D, of hydrogen in pure iron in the range of 1547" to 1726°C can be represented by the following Arrhenius relation: D(sq cnz per sec) = 3.2 x X exp(- 3300 i 1800/RT) where the uncertainty in the activation energy corresponds to the YO pct confidence level. Oxygen in the melt (above 0.015 pct 2) increased the apparent rate of absorption of hydrogen. The importance of diffusion data on liquid metals for predicting the rates of certain metallurgical processes has been recognized for a long time. Moreover, these data are much needed to test and develop theory for diffusion in liquid metals. Despite this practical and theoretical interest, however, relatively little reliable information about diffusion in liquid metals is available in the literature. This is particularly true for gas components such as hydrogen, oxygen, and nitrogen in liquid metals, where almost no data on chemical diffusion coefficients are to be found. This is probably due to a multitude of experimental difficulties particularly associated with high-temperature melts. In an effort to fill this gap in information, a research program was undertaken to study the diffusivities and rates of solution of gases in liquid metals. This paper presents the results of a study of the diffusion of hydrogen in liquid iron. EXPERIMENTAL METHOD Two methods for the study of the kinetics of dissolution of gases in liquid metals are being employed in this laboratory. Both involve the measurement of the volume of gas absorbed by the melt as a function of time and as such both avoid the uncertainties involved in chemical analyses of quenched samples for relatively small amounts of gas. In the first method, the gas dissolves in an inductively stirred melt and, in the absence of a slow surface reaction, the results are often interpreted in terms of mass transport across a liquid "boundary layer" between the homogeneous gas phase and well-stirred part of the melt. Other interpretations of the results of such experiments have also been described in the literature.1'5 In the second method a gas-liquid metal diffusion cell is used.' The gas dissolves in a cylindrical column of stagnant liquid metal and, in the absence of a slow surface reaction, the results are interpreted in terms of a non-steady-state diffusion solution to Fick's second law. The weakness of the first method is that while it gives information on the mechanism of absorption by stirred melts it yields an overall rate constant which even in the simplest cases depends on the nature and the thickness of the "mass transport layer" or "boundary layer". It yields no values of diffusion coefficients. The second method was used in this research because in many cases it is possible to determine the diffusion coefficient of the gas component in the liquid metal. In this research it has been utilized to measure diffusion coefficients of hydrogen in liquid iron. The apparatus used was essentially the same as that described by Mizikar, Grace, and par lee but certain modifications have been introduced to meet the elevated temperatures and special conditions of this research. Fig. 1 is a schematic drawing of the apparatus and Table I gives the identification of various parts in this figure. The diffusion cell, shown in detail in Fig. 2, was formed by immersing an impervious alumina tube (hereafter called absorption tube) in a bath of pure liquid iron contained in an alumina crucible. Two types of tubes were used, Morganite triangle RR and McDanel AP35. The crucible was contained in a vertical impervious alumina combustion tube (32 mm ID by 914 mm long) which was closed at both ends by water-cooled brass heads employing O-ring compression seals, Fig. 1. A protection tube enclosing a Pt, 5 pct Rh-Pt, 20 pct Rh thermocouple was introduced through the lower end of the combustion tube

Jan 1, 1968

By O. W. Simmons, L. W. Eastwood, C. M. Craighead

Binary alloys of titanium with silver, lead, tin, nickel, copper, beryllium, boron, silicon, chromium, molybdenum, manganese, vanadium, iron, and cobalt were studied. One-half-pound ingots of the alloys were prepared in an arc furnace, employing a water-cooled copper crucible, an argon atmosphere, and a water-cooled tungsten electrode. The half-pound ingots were fabricated by forging at 1700°F in air to 1/4-in. slab, followed by hot rolling at 1450°F to 0.060-in. sheet. Tensile properties, minimum bend radii, hardnesses, response to heat treatment and aging treatment, and phase relationships were determined for these alloys. EARLY in 1947, as one phase of the evaluation of materials for Air Force Project RAND, Battelle successfully arc melted Bureau of Mines titanium and obtained a few basic properties of unalloyed titanium and several titanium-base alloys. The low density, excellent resistance to corrosion, and high tensile properties of these materials stimulated a great deal of interest among metallurgists and designers seeking better materials of construction. As a result of this early work, Battelle, under contract with the Air Materiel Command, Wright-Patterson Air Force Base, has continued extensive studies of titanium alloys. The result of the first year's work is described in three papers. The present one deals with binary alloys, the second with ternary alloys, and the third paper with quaternary alloys. Melting Method The arc furnace for melting titanium and other refractory metals was developed at Battelle Institute under Air Force Project RAND. During the present work, considerable improvement has been made in the design and operation of this furnace for making small ingots of titanium and titanium alloys. The improved furnace design is illustrated by fig. 1, which shows a cross-sectional view with the dimensions of various parts and their relationship to one another. The essential features of the furnace are the inert argon atmosphere, the water-cooled copper crucible, and the water-cooled tungsten elec- trode. The melting crucible is formed by spinning 0.064-in. annealed copper sheet. A groove for an O-ring seal is spun into the flange of the crucible. A fiber gasket between the crucible flange and the water-cooled brass cover provides electrical insulation. The brass cover is fitted with a sight glass, an opening for the water-cooled electrode, and a tube through which the material is charged. Direct current is used for melting, with the positive electrical terminal connected to the water jacket and the negative terminal to the electrode. A typical heat is made in the new furnace as follows: Approximately, 0.20 lb of titanium under 2 mesh per in. and the alloy addition, if any is to be used, are placed in the bottom of the crucible. The cover is clamped on the crucible so that the O-rings make a tight seal. The remainder of the charge is placed in a glass bottle, and this is connected by a rubber hose to the charging tube of the furnace. The crucible and the charge are evacuated with a mechanical pump to a pressure below 50 mm of mercury, or less if desired, and held at this reduced pressure for 5 min. Hot water is circulated through the jacket during the evacuation period to assist in outgassing the crucible. Following the evacuation, tank argon of 99.92+ pct purity is flushed through the crucible for 5 min and then adjusted to give a positive pressure of 1 to 2 psi. During subsequent operation, an argon pressure regulator introduces only enough argon to compensate for the small leakage which occurs through a mercury trap. Re-evacuation and reflushing the melting chamber with argon produced a negligible reduction in contamination. Two 550-amp generators, connected in parallel, constitute the power source. Normally, about 800 amp are used for melting alloys which are not extremely refractory. The generators are set for 90 v open circuit and 200 amp. The arc is struck and the electrode is withdrawn to produce an arc of 23 to 26 v. This voltage is maintained while the electrode tip is moved slowly around a circle 1 in. smaller than the diameter of the ingot. The current

Jan 1, 1951

By Walter Miller

The remarkable strides which have been made in recent years in the art of petroleum refining are not fully apparent until we attempt to compare the scientific status of the industry today with the basic conditions existing a decade or so ago. The spotlight has played so strongly on the development of cracking that many of the wonderful steps brought about in other departments have crept upon us unawares. A number of causes have contributed to this highly accelerated rate of progress. Constant effort by both companies and individuals to obtain the honors and prizes rewarding new discoveries has played its usual important part in our industry as in others. Competition has applied its continuous pressure on the refiner to reduce costs and losses and increase the proportionate yields of the higher-valued fractions. Advances in the engineering professions and growth in chemistry and allied sciences have contributed much. But there are other factors which deserve particular mention. The rapid development of the internal combustion engine, with the rigorous quality requirements and large quantity consumption of both fuel and lubricants has been a tremendous influence in adding impetus to natural progress. The teaching of petroleum principles and practices in many of our best universities and technical schools, and the calling into the industry of ever greater numbers of scientifically trained men to supplement the efforts of the practically trained operators, as well as to apply at close hand the fundamentals of science as a life work, has had and is having an incalculable influence. Important Improvements Let us consider briefly some of the most important improvements: First, distillation, which constitutes the greatest single phase of refinery operations, even with cracking excluded; that phase of distillation being handled as an individual subject in this symposium. Today we are distilling crude oil and redistilling by-products at a rate very much faster than was possible with the lesser knowledge of the art which we possessed

Jan 1, 1927

By A. Perry Thompson

Discussion of the paper of A. PERRY THOMPSON, presented at the San Francisco meeting, September, 1915, and printed 'in Bulletin No. 100, April, 1915, pp. 645 to 677. ARTHUR S. EAKLE, Berkeley, Cal.-At the old Morning Star mine in Alpine County, where large masses of enargite were found some years ago, I looked particularly for evidences of replacement of pyrite by the enargite. While I have not made a particular study of any of the specimens, I judge that the pyrite and enargite were precipitated together. They were both primarily in those rocks. Of course, by using Mr. Graton's method of determination we might possibly find a situation somewhat different, but I should say that the enargite is not replacing the pyrite, but was simply precipitated at the same time. The bodies occurred there within 50 ft. of the surface, so it is probably not a case of secondary enrichment. H. W. TURNER, San Francisco, Cal.-In the case where secondary chalcocite shows a crystalline structure and cleavage lines, what is the evidence of the secondary nature of it? C. F. TOLMAN, Stanford University, Cal.-You can find practically all the evidences we have discovered in the microscopic study of ores. You can find all stages in the process of replacement of earlier minerals, especially bornite, by chalcocite, from a stage, in which the process has but just started with only occasional fragments of chalcocite set in bornite, to a stage where remnants of bornite are set in chalcocite. The replacement may take place along the cleavage lines or along the crystallographic directions of the earlier mineral, or it may take place irregularly. In one type of replacement you may find in one spot a few cross-cutting veins, and in another spot the latter may be so enlarged that there remain only a few individual specks of the replaced mineral.

Jan 12, 1915

By A. H. Larson, R. J. McClincy

The activity of Sb,03 in PbO-Sb,03 slags containing less than 50 mol pct Sb,03 was determined by the inert-gas saturation method at 700°C. In this composition range, the activity gf SbzO3 shows a strong negative deviation from ideality. The activity of PbO in these slags was calculated by application of the Gibbs-Duhem iniegration to the Sb203 activity data. The calculated activity of PbO in slags containing more than 63 mol pct PbO was found to deviate in a positive direction from ideality uthile a negative deviation was found for slags containing less PbO. The standard Gibbs free energies of formation of Sb,03 and PbO. Sb203 have been calculated and compared with existing data in the literature. The activity of Sb203 in PbO-Si0,-Sb203 (PbO/SiO, = 2) slags containing less than 25 mol pct Sb,03 was also determined by the inert-gas saturation method at 700°C. In this composition range, the activity of Sbz03 shows a very large negative deviation from ideality. VERY little experimental work has been published in the past to determine equilibrium data in the oxide systems connected with the refining of lead. These data are of value since impurities such as antimony, arsenic, and tin must be removed from lead and recovered for further treatment. Equilibrium studies on antimony and arsenic systems are also of interest for the design of new processes for lead refining and lead dross treatment. Maier and ~incke' first determined the liquidus curves for the PbO-Sb203 system and identified the compound PbO . Sb203. They found the phase diagram for this system to be two simple eutectics located on either side of the congruent melting compound. They also determined a very limited amount of vapor pressure data for Sb406 abbve PbO-Sba3 melts at 697"~. A second phase diagram investigation on this system was reported by Hennig and Kohlmeyer' who confirmed the existence of the compound PbO . Sb203 as well as the form of the diagram. A disagreement was noticed, however, in that their liquidus temperatures over nearly the entire composition range were higher than those reported by Maier and Hincke. Barthel~ and pelze14 redetermined the liquidus curve at the PbO-rich end of the PbO-Sb@, system and agreed very closely with the results of Maier and Hincke. None of the investigators mentioned above reported any mutual solid solubility in the PbO-SbD3 system. Zunkel and Larson5 have determined the phase diagram for the PbO-rich end of the PbO-Sb203 system by slag-metal equilibrium studies in the Pb-PbO-Sb203 system and by thermal analysis studies in the PbO-Sbz03 system. A maximum solid solubility of 5.6 mol pct Sb203 in PbO was observed at the eutectic temperature of 604°C. Their results for the phase diagram agree favorably with those of Maier and Hincke. The vapor pressure of Sb2O3 in the temperature range from 470" to 800°C has been determined by Hincke, using a modification of the transportation meth~d.~ His results for temperatures below the melting point of Sba3 are the only data reported in the published literature. The predominant vapor species has been shown to be Sb,06 by Norman and staley.? Myzenkov and Klushin,8 using the boiling-point method, have determined the pressure of Sb406 above liquid SbD3 in the temperature range from 715" to 1025°C. The agreement between these two studies is not very close. A portion of the discrepancy lies in the fact that Hincke used silica crucibles, which were attacked by the liquid Sbz03 at high temperatures. This fact does not account, however. for the large difference observed at the melting point. ~aier' gives a brief summary of vapor pressure data for Sb,O, above pure liquid Sbz03 which agree quite well with the data of Myzenkov and Klushin at temperatures near the melting point. This paper describes the determination of Sb2O3 activity data in the PbO-Sb203 and Pb0-Si02-Sb203 (PbO/SiOz = 2) systems by the inert-gas saturation method. These activity data are compared with the data calculated by Zunkel and arson. EXPERIMENTAL Materials. The materials used in this investigation were analytical reagent-grade PbO (99.8 pct PbO, 0.14 pct insoluble in CHsCOOH, 0.02 pct not precipitated by HB, 0.1 pct CaO, and 0.08 pct SiOz), Sbf13 (99.6 pct Sb203, 0.004 PC~ C1-, 0.005 PC~ SO;-, 0.15 p~t AS, 0.001 pct Fe, and 0.03 pct other heavy metals such as Pb), and SiOz (chromatographic grade). Apparatus for Vapor Pressure Determinations. The apparatus used in this investigation consisted of a transportation reaction system with two separate gas trains. The argon transporting gas was first mixed with a small amount of hydrogen, metered, and dried by passage through silica gel and anhydrone drying tubes arranged in series. After this preliminary drying, the argon was passed through copper wool at 500°C to convert the residual oxygen to water vapor which was removed by three anhydrone drying tubes. A second stream of argon was metered and dried and then passed around the outside of the alumina reaction tube to flush away the volatile species to pre-

Jan 1, 1970

By J. J. Kramer, W. A. Tiller, G. F. Bolling

The solidification of poly crystalline zone-refined lead has been examined. A novel casting technique was used, with several advantages such as unidirectional heat flow, atmosphere control, and decanting of the liquid during any stage of growth. The experimental results show the separate existence of two textures, a (111) surface texture at the chill surface and a texture in the columnar zone, in the absence of conditions which would produce dendritic growth. WALTON and chalmers have most recently shown that the dendrite direction is the preferred axial orientation for the solidification of many metals in casting. Experimentally, for aluminum and lead, they showed that in the columnar zone the dendrite direction, <l00>, predominated, developing from an equiaxed chill cast layer that exhibited no preferred orientation. A reasonable description of the way in which grains closer to the dendrite orientation were able to encompass other grains was then set forth. For their materials, it was also shown that high superheats could inhibit a preferred axial orientation from developing, presumably by inhibiting dendrite growth. The observations of Rosenberg and iller, on the other hand, showed that zone-refined lead, cast under conditions similar to those of Walton and halmers,&apos; had a definite <111> texture in the columnar zone. However, no examination was made of the chill surface to find out if the columnar zone texture was independent of the orientations at the surface. Since the existence of preferred growth in Upure" lead is thus in doubt, a reexamination of the casting of zone-refined lead is presented here, using a novel casting technique. EXPERIMENTAL PROCEDURES AND RESULTS Zone-refined lead was prepared from two starting materials;99.999+pct supplied by ASARCO, and 99.999pct supplied by COMINCO. The manner of zone-refining and the phenomenological tests for purity after refining, have been describedelsewhere.&apos; The casting apparatus is shown schematically in Fig. 1. The following general procedure was used: The metal was cut directly from the best parts of

Jan 1, 1963

POSITIONS VACANT (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons.) Superintendent for iron mine operated on the sub-level and caving system. Small output, moderate salary. Location, Southern State. No. 45. Chemist to sample and analyze iron ore. Experience in other branches not essential. Location, Southern State. No. 46. ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introducd by members.) Experienced mine superintendent desires position. Several years&apos; experience in practical management of mining and development work. Has also practiced ass consulting engineer and is thoroughly experienced in the examination and development of mining properties. Mexican experience. Will go anywhere for reliable concern. Salary moderate. References. No. 254. Member, mechanical superintendent, wants position. Has had 12 years&apos; experience as master mechanic of smelting plants in United States and Mexico. Also superintendent of shops doing marine, mining, and general contracting work. . Experienced in manufacture of mining tools and equipment. Up to the minute in copper, lead, and zinc smelting. Has learned a learned a great deal, can forget much, and has the inclination and ability to learn more. Best of references. No. 255.

Jan 10, 1915