Search Documents

By A. W. Doepke

CLIMAX is situated in the heart of the high Rockies at Fremont Pass on the Continental Divide. This setting naturally throws some of the romantic aura of the old mining camps around the town. In its early days it was much like them, even to its air of impermanence. Its founders had faith in the future-as did every adventurer who started a hole in the ground and called it a mine. In those days, however, all available money was expended on the mine, and those who labored on the job had to he content with rugged living arrangements. The visitor at Climax today. however, sees a townsite carefully laid out to enhance the natural' beauty of the surroundings. There are 250 houses and 43 apartments which have been carefully designed by an architect, and missing is the long line of houses of the same type. Every house is of a different design, all being modern in every respect, with haths, running water, electricity, and .sewage disposal. They vary in size from three to six rooms and rent for $5 per room per month. A complete, well-designed water-treatment plant supplies water for domestic purposes.

Jan 1, 1946

By K. E. Beu

IN the measurement of retained austenite concentrations in steels using the integrated intensity method,1 Averbach has pointed out" that the absorption factor A(0) for a flat sample making a glancing angle 4 with the incident X-ray beam can be combined with his constant factor R to obtain our constant factor" G provided that "1—There is no preferred orientation in the sample, and 2—The geometric requirements [for the sample, film, and X-ray beam] have been met precisely."' If A(0) can be combined with R to give G according to the equation G = R . A(0) [14] then the possibility for making non-compensating errors in the austenite determination has been eliminated. This has been described previously in a technical note." Because of the brevity of the previous note,3 it was impossible to emphasize the fact that the two conditions on preferred orientation and geometry can be easily met experimentally, contrary to Aver-bach's statement that: ". . . the necessary conditions must be tested experimentally for each determination, and this is done most easily by observing whether the apparent absorption has the form of Eq. 2 [the theoretical equation for A(0)]."" he way in which these two conditions can be met experimentally will be discussed briefly to help clear up this point. In addition to these two conditions, other factors such as sample shape, homogeneity, and grain size which also affect A will be included in this discussion. A (0) depends on sample shape. The theoretical function for A was derived originally for a flat surface.' In general we have found that a flat sample surface is readily obtainable." If such a surface can * The effect of surfaces which are not flat on the measurement of retained austenite will be discussed later. be obtained, it has the following advantages: 1—it is easily reproducible from sample to sample, 2—it is the form required for metallurgical examination —this type of examination being frequently desirable for this work, and 3—it is an efficient shape for diffraction purposes. Perhaps the most important of these features is that a flat sample surface is easily reproducible; hence, this requirement on the repro-ducibility of A from sample to sample is met for all such samples. Fig. 1—Schematic diagram of the quartz crystal monochromator diffraction unit. The centerline of the main beam is at 6' to the target face. The tangent to the crystal face is at 16.8' to the moin beam. The centerline of the monochromatic beam is at 33.6 to the main beam. The sample surface can be rotated in its own plane. The angle of the sample surface and the monochromatic beam can be adjusted by rotating about the vertical axis, The film holder can also be rotated about B so that the film can be exposed over the desired angular range. For Fe K, X = 1.932A. 1011 planes of quartz have d = 3.35A. A(0) depends on homogeneity and grain size. If the sample is badly segregated or the grain size is large, the effect of micro-absorption and primary extinction1. ' must be considered. It has been shown, however, that for most plain carbon or low alloy hardened steels, neither micro-absorption nor primary extinction effects are present.' A (0) depends on camera geometry. For a given angle 0, A remains theoretically constant from a geometrical viewpoint only if the following factors are kept constant: 1—the angle of inclination .+ of the sample to the X-ray beam, and 2—the centering of the sample with respect to the film cylinder. These are mechanical problems which can be solved readily if the facilities of a good machine shop are available. The arrangement used to insure that the angle 4 remains constant and the centering of the sample is reproducible is indicated schematically in Fig. 1. The sample is clamped against a thin plate with a hole in it by means of a spring-loaded pres-

Jan 1, 1954

By John D. Price

COAL blending, in the preparation of coal before coke making, is so commonly practiced as to be almost universal. But the reasons underlying this practice, the benefits resulting from it, and the materials used in blending vary widely. This paper will outline the various phases of the subject and present information which may be correlated with work that has been done elsewhere. It will deal entirely with work done on the high-volatile coking coals of the western part of the United States, special emphasis being given to the coals of Colorado and Utah. A surveyL of the 86 coke plants in active operation in the United States during 1949 indicates that only 9 plants, or 10.5 pct of the total, charged one single rank of coal into their ovens, while the remaining 89.5 pcl made use of blending in some form. This report indicated that of these total plants 5 used straight high-volatile coal, 4 used straight medium-volatile coal, 47 used blends of high and low-vola-tile coals, 25 used blends of high, medium, and low-volatile coals, 2 used blends of high and medium-volatile coals, 3 used blends of medium and low-volatile coals. The fact that certain plants operated on a single kind of coal should not be interpreted to mean that no blending was practiced there, for invariably such plants secure their coal from more than one source and in the interest of uniformity do blend the coals as received. The general term coal blending covers two fields, the first of which is the mechanical mixing of a number of coals to secure uniformity. Often it is found necessary to secure coal for coke production from a number of different mines; these coals, though of the same general type or rank, may differ in their chemical composition or in the physical qualities they impart to coke made from them. Again, it is not unusual to find that coal from different sections of the same mine may show variations in quality. Under such conditions it may be necessary, in the interest of a uniform final product, to introduce a system of blending bins, a bedding yard, or other mechanical methods of securing a uniform mixture. Unfortunately this form of blending has received very little attention up to the present time; it has not received the consideration its value merits. The second type of blending, while also for the purpose of coke improvement, deals more particularly with the use of a blending agent differing in character from the base coal: it is this form of blending that will be discussed here. To consider only the western coals, for blending may be found necessary for other reasons with other coals, blending has been practiced experimentally or commercially under the following conditions: 1—When a single coal or mixture of coals of the same rank does not produce a satisfactory coke. For example, a high-volatile coal when used alone is likely to contract when coked so that a comparatively weak coke is formed. Or, if of very low rank, the coal may be deficient in the necessary bitumens required for good coke production. 2—When a product of some special quality is required, for example, when a plant ordinarily producing blast furnace coke must operate at slow coking rate to produce a high-grade foundry coke. Under this condition the reduced daily production of all products which accompanies slow coking time may be undesirable, and the use of some blending agent to increase the size of coke made at faster coking rates may be necessary. 3—When greater yield of coke or its coproducts is needed. Depending upon economic values of the products it may be found desirable to increase the yield of one or the other. 4—When supply of a particular coal must be used, either to protect reserves of high quality coking coal or to utilize a surplus or inferior product not otherwise usable. Many materials have been used for blending purposes, the exact agent to be used depending both upon the condition to be corrected and the nature of the base coal. No universal blending agent that can

Jan 1, 1954

Annual Meeting, February 17 to 19, 1914.-The following Committees have been appointed to have charge of the arrangements for the Annual Meeting in New York City: . General Committee: Louis D. Huntoon, Chairman; Arthur S. Dwight, Vice-Chairman; W. deL. Benedict, George F. Kunz, Thomas T. Read, E. Maltby Shipp. Reception Committee for Each Day: Chairmen to be announced later. Banquet Committee : Theodore Dwight, Chairman. Luncheon Committee: E. Maltby Shipp, Chairman. Ladies' Committee: Mrs. Arthur S. Dwight. Badge Committee : George F. Kunz, Chairman; E. Maltby Shipp, Vice-Chairman. Program Committee: Thomas T. Read, Chairman. Bureau of Registration and Information: Burr A. Robinson, Chairman.

Jan 1, 1914

By AIME AIME

TWO technical sessions, an excursion through the Midwest refinery and a smoker, marked the first day of the meeting of the Petroleum Division at Casper, Wyo., on Aug. 28. Ninety-nine members and guests registered and there was an excellent attendance at 'all functions. The -local committee under the general chairmanship of J. C. Lindsay, general manager of the Western Pipe Line Co., had made every possible arrangement for the convenience and comfort of the visiting members and the Program Committee under E. L. Estabrook, vice-chairman of the Petroleum Division, had brought together a most interesting series of technical, papers. The meeting centered mainly on the various features of the Salt Creek field but there were also contributions from the technology of production in California, the Mid-Continent, and the Texas fields. The opening session was called to order by Mr. Estabrook at the Townsend Hotel on Friday morning. The members and visitors were welcomed appropriately by Ex-Governor B. B. Brooks, president of the "Rocky Mountain Oil and Gas Association, who recalled the changes that had taken place as Casper, a frontier cow town, became a thriving oil metropolis. F. Julius Fobs, chairman 'of the Petroleum Division, responded and then took the chair. He introduced H. Foster Bain, Secretary of the Institute, who expressed the regret of those members members who found it impossible to stop over en route to Salt Lake City and his own pleasure at meeting with the Division in the field. Following these introductory ceremonies the technical session began with a "Sketch of the Geological Formations of Central Wyoming," presented by J. G. Bartram of the Midwest staff. It was brief and to the point and contributed greatly to the easy under¬standing of the succeeding papers by those unfamiliar with the region. The talk was illustrated by a large scale columnar section -and a copy of the excellent, geological map of the State recently issued by the U. S. Geological Survey.

Jan 1, 1925

By J. E. Berg

THE geology of the Coeur d'Alene mining district is so familiar to every one interested in mining that I will only note as an introduction that the main producers are mines whose orebodies lie in the Revett or Burke quartzites ; that the known orebodies in the eastern part of the district all lie north of the Osburn fault; that the Prichard formation is quite generally looked upon as being unfavorable for lead deposits ; that the monzonite intrusive mass extending north from Gem to Sunset Peak, and over into Cedar Creek divide, is considered to have been the prime agent in the crea-tion of our orebodies, and that diabase dikes are a quite common feature at most of the properties with which I am familiar. Some of the exceptions to these statements may be mentioned. The Interstate-Callahan mine is considered the exception disproving the alleged relation between large ore-deposits and the Prichard formation, but this property was primarily a zinc producer, with lead secondary, though of sufficient tonnage to be a valuable product. A second interesting occurrence in the Prichard worth calling to your attention is the Jack Waite property, on Tributary Creek, north of Murray. This vein lies at a low horizon in the Prichard forma-tion, and the ore differs essentially from others in the same horizon elsewhere in that it is a clean, medium to coarsely crystalline, lead ore carrying very little zinc, about one ounce silver to ten units lead, and is accom-panied by a clean quartz gangue or vein filling. I believe that quartz was the primary mineral in the fissure, and that the lead ore was deposited in the vein as a replacement of the quartz.

Jan 7, 1927

IT is a pleasure for the translators to record their gratitude to the Seeley W. Mudd Memorial Fund of the American Institute of Mining and Metallurgical Engineers for underwriting the cost of publication of this volume, to the Printing-Office of the Yale University Press for doing an unusually fine printing job, and to the following for granting permission to reproduce the title pages of volumes in their collection: The Bibliothèque Nationale of Paris, for edition A of the Bergbüchlein; the Osler Library of McGill University, Montreal, for editions B and G of the Bergbüchlein and edition D of the Probierbüchlein; Mr. Herbert Hoover, Jr., for editions C and E of the Bergbüchlein and editions E, M, N, and 0 of the Probierbüchlein; the Parsons Collection of the Reference Department of The New York Public Library, for edition D of the Bergbüchlein; the Library of the Bergakademie Freiberg, for edition F of the Bergbüchlein and editions A, H, and L of the Probierbüchlein; the Herzog August-Bibliothek of Wolfenbüttel, for edition C of the Probierbüchlein; the British Museum. Library, London, for edition I of the Probierbüchlein; and the library of the University of California at Berkeley, for edition J of the Probierbüchlein. The cooperation of those who helped with the translation of the Bergbüchlein is acknowledged on p. 64. A. G. S. C. S. S.

Jan 1, 1949

By S. G. Proctor, D. L. Baaso, W. V. Conner

A double crucible system was developed for I-g scale plutonium reductions. The equipment consists of an inner MgO crucible, an outer MgO crucible, and a stainless steel pressure vessel. The reduction charge is PIaced in the inner crucible and the annulus between the inner and outer crucibles is filled with a mixture of calcium and iodine. The exothermic reaction between the calcium and iodine in the annulus supplies the heat required for complete reaction of the reduction charge ana' good metal coalescence. Metal yields of 80 to 85 ,pct were obtained from I-g scale reductions and yields as high as 97.5 pct were obtained from 0.5-g scale reductions. The system was used to reduce charges containing as little as 0.1 g of Pu resulting in metal yields up to 90 Pct. THIN metal foils of highly enriched plutonium isotopes are used as targets for cross section and other measurements. The isotopes are separated in the calutrons at Oak Ridge and are very expensive to prepare. Often, only 1 or 2 g of material are available thereby emphasizing the need for a method of preparing these small quantities of metal. Procedures for 1-g scale plutonium reductions have been described, but these procedures require elaborate or expensive equipment. For example, the procedure described by Anselin et al.1 requires an inert atmosphere glovebox and induction heating equipment. The procedure described by Baker2 also uses induction heating equipment to obtain the recommended heating rates and liner temperatures. Baker's procedure also requires high purity PuF4 with very little PuO2 present. The procedure described in this paper resulted from a search for a simple and inexpensive method for making 1-g scale plutonium reductions. EXPERIMENTAL Equipment. The equipment required for the double crucible system consists of a pressure vessel, two MgO crucibles, a MgO crucible lid, and a resistance-heated, vertical crucible furnace. The crucibles were slip cast from high purity MgO and were supplied by the Coors Porcelain Co. and the Norton Co. The pressure vessel and lid were fabricated from 316 stainless steel. Materials. The PuF4 used for this study was obtained from the P1utoniu:m Metal Production Department at Rocky Flats. The PuF4 was prepared in a con- tinuous hydrofluorinator by reacting Pu02 with HF at 650°C. The isotopic composition of the plutonium was approximately 93 pct 239PU, 6 pct 240PU, and 0.5 pct 241PU. Some of this PuF, contained less than 1 pct Pu02 (Batch No. 6 and 7), while other batches contained up to 15 pct Pu02 (Batch No. 3). The chemical analyses of all the PuF4 used for this study is given in Table I. The calcium was 99 pct pure, AEC grade, and only that fraction which would pass through a 20 mesh screen was used. The I2 was USP grade re-sublimed I2 which was ground before being used. Procedure. Various charge compositions and methods for loading the double crucible system were tested. The optimum conditions for 1-g scale reductions are described below. The double crucible system was loaded as shown in Fig. 1. The outer crucible was placed in the pressure vessel and the annulus between them was filled with MgO sand. The inner crucible was placed in the outer crucible, supported by a layer of MgO sand in the bottom of the outer crucible. A mixture of 5.2 g of Ca and 25 g of I2 was placed in the annulas between the two crucibles. The upper portion of the annulas was filled with MgO sand. Next, a layer of a mixture of calcium and I, equal to 20 wt pct of the calcium and I2 used in the main charge was placed in the bottom of the inner crucible. The PuF, to be reduced was mixed with a 30 pct excess of calcium and 1 mole of I2 per mole of Pu and this mixture was placed in the inner crucible. The charge was topped with a layer of a mixture of calcium and I2 equal to 20 wt pct of the calcium and I2 used in the main charge. The pressure vessel was sealed with a flat copper gasket and was purged by alternately evacuating and filling with argon. The purge valve was closed and the vessel was placed in a vertical crucible furnace which was preheated to 950°C. The furnace was turned off after 20 min of heating and the vessel allowed to cool. Experience has shown that. this amount of heating is sufficient to assure complete reaction of the charge. RESULTS AND DISCUSSION The double crucible system has been used to produce plutonium metal on a 0.1- to 1-g scale. Reduction

Jan 1, 1970

By D. M. Schuster, E. Scala

The elastic effects occurring in the matrix of a composite reinforced by discontinuous fibers were studied by means of photoelastic techniques. A hirefringent plastic was employed as the matrix material with high-strength a Al2O3 whiskers as the reinforcing fibers. It was found that for whiskers aligned parallel to the tensile load direction: (I) Matrix reinforcement occurred along the length of the whisker to within about 5 diameters of the whisker tip for a length to diameter ratio, L/D, of 40. (2) Significant stress concentrations were created in regions immediately surrounding the tips; the fine as-formed tapered ends exhibited the minimum stress concentration whereas the square-ended whisker produced relatively high values, K r 2.5 for L/D = 40. (3) The axial and radial stress distributions could he determined quantitatively; the stress distribution at the whisker-matrix interface was in general agreement with theoretical calculations. (4) The highest source of stress concentration occurred at points of fracture in whiskers which had ruptured after incorporation into the composite. Whiskers aligned perpendicular to the load direction neither reinforced nor caused appreciahle stress concentrations in the matrix. ThE properties of composites have generally been formulated empirically on the basis of macroscopic tests. There are still many questions concerning the mechanical and chemical interactions occurring at the interface between the reinforcing fiber and its matrix. Continuously reinforced plastics and dispersion-hardened metals represent the two extremes of composite reinforcement. Whether artificially produced or formed in situ, the whisker composite falls between these two extremes and is an example of discontinuous fiber reinforcement. The effect of fiber shape, size, surface condition, and end configuration on the stress distribution in the matrix is important since the presence of stress concentrations, especially in any high-strength, thin-wall structure, could become the cause of catastrophic failure. DOW,' in his theoretical discussion of discontinuous fiber reinforcement, has pointed out that appreciable stress concentrations occur at the tips or ends of the reinforcing fibers. It is the purpose of this study to examine directly, by means of the photoelastic technique, the stresses which occur in the vicinity of a discontinuity or whisker tip and to measure qualitatively and quantitatively the effects of whisker geometry when embedded in a birefringent matrix material. The use of sapphire (a A1,O3) whiskers was decided upon as the reinforcing agent because of their high elastic modulus (E- 60 X 106 psi) and in some cases strengths in excess of one and a half million psi. Sapphire whiskers are of further practical interest since they retain large fractions of their strength up to temperatures approaching the melting point (3720oF).2 The whiskers were grown, by the vapor-phase reaction commonly employed,3 as part of this study to insure a physically uniform supply. Tensile and bend tests were performed to verify that the whiskers were of the expected ultra-high strength. The high-strength whiskers can be identified and selected from the combustion boats by surface perfection, shape, and size; otherwise, strength values can vary by a factor of ten or more. Macroscopic defects are quite common on the surface of large bladed whiskers and the principal experiments were conducted with hexagonal whiskers of about 0.002 in. diameter and lengths ranging from 0.1 to 0.4 in. Upon completion of these two phases of the experiment, several birefringent resins were evaluated. A plastic, developed by Zandman,4 which is supplied by the Budd Co., was found most suitable and was used as the matrix material for the whisker composite throughout the study. It has a sensitivity of 60.5 lb per in. order, calibrated in tension and cures without introducing residual stresses. Young's modulus for this matrix material is 430,000 psi in the fully cured condition. Since good wetting and bonding between the sapphire and the matrix material is essential to the interpretation of the results, a wettability test was performed. The contact angle was measured to be 168 deg where perfect wetting is defined as 180 deg; therefore, the Budd Plastic wets the sapphire

Jan 1, 1964

W. M. PEIRCE, Chairman J. L. CHRISTIE, Past-chairman E. H. DIX, JR., Vice-chairman ALBERT J. PHILLIPS, Vice-chairman E. M. WISE, Secretary International Nickel Co., Bayonne, N. J. W. M. CORSE, Treasurer Executive Committee W. H. BASSETT, JR. R. H. LEACH' D. K. CRAMPTONR. F. MEHL J. A. GANN W. E. REMMERS G. O. HIERS H. J. ROAST JEROME STRAUSS Finance Committee J. L. CHRISTIE, Chairman W. M. CORSE C. H. MATHEWSON T. S. FULLER H. S. RAWDON

Jan 1, 1934

By AIME AIME

ALL sessions of the Mining Geology Committee at the Annual Meeting this year were held jointly with other groups, a plan that seemed to work out to the satisfaction of every one. Certain of these sessions are reported in this issue by others; the ones held on Wednesday are covered here. Ten papers, as published in the February M&M, were on the program for the Wednesday morning session, held jointly with the Society of Economic Geologists. Mr. Eckel made a brief presentation of his paper, on which there was no discussion, and Mr. Peoples presented that of which he was a joint author. D. M. Fraser then discussed a gravimeter survey for chromite in Cuba, which blocked out some 50,000 tons of ore, and F. G. Wells told of work on chromiferous sands in Oregon.

Jan 1, 1943

By James T. Kemp

AN historical society of particular interest to mining engineers all over the world was born in Cornwall in 1935. A hundred-year-old winding engine then finished its long labors at the Levant mine on the cliffs near Lands End, England. The engine was to be dismantled and scrapped. A few men living near-by, appreciating that this event was one of the final acts in closing a long century of extraordinary mining and engineering evolution. armed a committee to prevent the destruction of the old mine hoist and succeeded in purchasing the engine. They restored the engine house and in time arranged with the Manor of Trewellard, owners of the land, for a 99-year ground lease on a peppercorn rental.

Jan 1, 1947

By Wallace W. Wilson

This DaoerAA calls to attention for the first time, to the writer's knowledge, a purported recovery of oil by substantially horizontal gas cycling that is considerably in excess of 50 per cent of the oil originally in place. The average angle of dip along the path of travel of the gas is less than one degree of arc. The best recovery by gas cycling previously brought to the writer's attention1 occurred in the case of the Mile Six Field in Peru, where about 68 per cent of the original oil in place has so far been recovered. In this case, however. the recovery was greatly aided 1)y the high dip angle of about 17.5". An approximate estimate of recovery was made by the method developed by the writer' for the case of the Cook Ranch Field, using an average relative permeability ratio function dictated by past experience with a number of good quality sandstones. A result of about 40 per cent recovery of the original oil in place wa* obtained after the 8.5 pore volumes of cumulative gas cycling undergone by the Cook Ranch Field. Tile writer desires to emphasize what appears to him as the sound engineering practiced at Cook Ranch, and also the care attending the taking of data and the high quality of the calculations made. It is impossible to take issue on factual grounds with any of the conclusions drawn in the paper. It is, however, desired to point out the difficulty of explaining the unexpectedly favorable oil recovery on ordinary theoretical grounds. It would be of interest to know whether relative permeability ratios have been measured on the Cook sand. The operator is inclined to attribute some of the excess benefit to settling of the oil across the bedding planes into the lower part of the sand. It is difficult for the writer to appreciate the importance of such an effect, inasmuch as the concomitant opening of excessive vacated pore space in the upper part of the sand would he expected to cause excessive bypassing of the gas. REFERENCE 1. Welge. H. J.: "A Simplified Method for Computing Oil Recovery by (Gas or Water Drive." Trans. AIME, (1952), 195, 91. AUTHOR'S REPLY TO MR. WELGE Welge has poined out clearly the difficulty of applying material-balance procedures in calculating the Performance of low-pressure, dispersed gas injection operations. There can be no argument that even with the most favorable assumptions of K,/K,, and with cumulative gas cycling in excess of normal expectations, the calculated oil recovery will be considerably less than the 72.5 per cent recovery realized from this project to Jan. 1, 1951. There probably are at least two reasons for the unusually high recovery from this reservoir, the effects of which would be difficult or impossible to calculate by known methods: 1. The operator did not use the same injection wells for the entire operation, and exercised considerable control over producing GOR by changing the locations of injection wells whenever well performance indicated excessive bypassing. Fifty-six wells were used for injection, not over 29 of which were in use simultaneously. This procedure resulted in frequent shifting of the fluid movement patterns in the reservoir and undoubtedly increased the ultimate recovery. The writer knows of no satisfactory procedure for calculating the effect of this practice. 2. Vertical movement of oil across the bedding planes of the reservoir rock hy gravity drainage tended to maintain a relatively high oil saturation, and hence a favorable K,/K, ratio, in the lower sections of the reservoir. As pointed out by Welge, this condition has aggravated the tendency for high producing GOR, but at the same time it has resulted in increased oil recovery. As may be seen from the performance charts for the various battery areas, operating (GOR'S have been quite high for the last several years of reported history.

Jan 1, 1952

THE Institute of Metals Division of the A. I. M. E. has joined with the American Society for Steel Treating and the American Welding Society in support of National Metal Week in Philadelphia, Oct. 8 to 12. Individual and joint technical sessions, plant inspection trips, and a general exposition to be held in Commercial Museum have all been arranged. With the coming of the Institute of Metals Division into the circle, the scope of the exposition has been broadened to cover non-ferrous metals, and exhibits of much interest are promised. Headquarters for the Institute of Metals and the American Society for Steel Treating will be at the Benjamin Franklin Hotel, and for the American Welding Society at the Bellevue-Stratford. The American Society for Steel Treating and the Welding Society will hold technical sessions each forenoon at their hotel headquarters. The Institute of Metals Division will hold sessions Tuesday morning and Wednesday and Thursday afternoons; that for Wednesday being a joint session with the American Society for Steel Treating. The latter society will hold independent afternoon sessions on Thursday and Friday. Registration and information desks will be open at the hotels throughout the week, and an attractive program of entertainments has been arranged.

Jan 1, 1928

By AIME AIME

THE organization of the Board of Directors was effected Tuesday afternoon in ' executive session. Messrs. Bassett,. Buehler, Cates, Daveler, Eavenson, Eilers, Elliott, Evans, Guess, Lovejoy, Moulton, Rickard, Tally, Turner,, Wraith and Wright being pres¬ent. Messrs. Tally, Bassett, Rickard, Mathews and Cates were chosen to form the Executive Committe with Mr. Tally as Chairman, and Messrs. Krumb, Guess and Moulton for the Finance Committee with Mr. Krumb as chairman. Karl Eilers was reelected as Treasurer and H. Foster Bain as Secretary, after which the Directors adjourned for the usual dinner reported elsewhere. At the open session of the Board, at which in addition Messrs. Allen and McAuliffe were present, the work of organization was continued with appointments to committees as listed herewith. Various actions of the Executive and Finance Committees were confirmed, the budget for 1931 formally approved, the meeting dates for the year adopted, 34 new Members and Associates, 13 Junior Members and 31 Student Associates admitted by election and transfer and 29 resignations accepted.

Jan 1, 1931

By John D. Hanks

INTRODUCTION Chevron's Uranium Mill is located near Panna Maria, Texas; 70 miles southeast of San Antonio. Designed by Kaiser Engineering, the Mill will process a nominal 2500 dry T.P.D. of uranium bearing ore containing 15% uncombined moisture. Earl Torgerson, San Mateo, California, is the consulting metallurgist on process design. Feed to the plant consists of a mixture of high, medium and low grade sandy day ore; the average grade of the ore will be 0.7% throughout the life of the project. The ore is delivered to the mill via truck and stored by type in individual piles on a flat storage area. The ore is fed by conveyor to a semi-autogenous grinding mill. The SAG mill discharge slurry is pumped either to a storage tank or to the first of five mechanically agitated leach tanks where both H2SO and NaC103 are added. Following leaching, the slurry is mixed with thickener No. 2 overflow before being pumped to a six-thickener, countercurrent decantation circuit where the solution containing uranium is separated from the leach residue. The residue is washed essentially free of solubilized U308 values at the sixth thickener and discharged to an adjacent tailings pond. The first thickener overflow, containing approximately 0.4 grams U308 per liter, is filtered for clarification and sent to the liquid ion exchange (solvent extraction) section. The pregnant aqueous solution is mixed with organic solvent containing amine on which the complex uranyl sulfate ions are absorbed. The immiscible aqueous and organic solutions are mixed and separated in each of the four stages of solvent extraction. The final pregnant organic is directed to a stripping section. A strip solution containing (NH4)2S04 (ammonium sulfate) and NH4C1 (ammonium chloride) is contacted and separated from the organic in each of the four mixer-settler units. The strip solution is mixed with NH3 and the uranium precipitates along with trace amounts of sulfate, chloride, and ammonia. After washing in a thickener, the uranium precipitate or yellowcake is centrifuged and dried in a multiple hearth roaster. Overflow from the yellowcake thickener is recycled back to the stripping section of the solvent extraction circuit. The dried yellowcake concentrate contains more than 98% U308; diluents include H20, ammonia, chloride, etc.. Impurity concentratons in the product are sufficiently low, after drying, to permit direct shipment to refinement installations. ORE RECEIVING Ore from one or more mines will be stored on a pad adjacent to the uranium processing mill. Ore stored in the area may total 200,000 tons or more, which is equivalent to over a two month treatment reserve for the mill. In addition to providing surge capacity, the proposed storage facility permits natural oxidation of the ore and affords an area which, in turn, improve plant U308 recovery and reduces consumption of oxidizing reagents. The uranium bearing ore is segregated at the storage area into several distinct types. One group can be identified by its sandy, clay-like matrix and will be distinguished by its U308 concentration of high, medium, or low. Other ores contain substantial quantities of carbonaceous shale, typical of ore in the area. Feed is recovered from any one or combination of piles, in accordance with operating requirements and recovery factors. The run-of-mine ore, at 15% moisture, is transferred to a stationary, 24-inch by 24-inch grizzly. Undersize material falls into a 280-ton surge hopper located below grade, while oversize material is removed for preliminary size reduction. A sump-pump is located at the reclaim hopper to recover excess mositure and ore spillage for processing. Plant feed is continuously drawn from beneath the hopper at an average rate of 120 tons per hour by means of an apron feeder. The hopper is equipped with a low level safety system to protect the apron feeder assemble. The ore is transferred to a belt conveyor, elevated and discharged into a semi-autogeneous grinding (SAG) mill. Water addition at the discharge point is automatically controlled by a feed rate, moisture analyzer system located on the belt conveyor. GRINDING Minus 24-inch ore, at a rate of 120 mosit tons per hour and cyclone underflow at a rate of 137 moist tons per hour are combined with a controlled 186 gallons per minute fresh, warm plant process water. The mixture, at an average 68% solids, is fed to the SAG mill. The viscous mass is subjected to grinding at a temperature moderately above ambient resulting from use of the 140ºF well water. The 16.5'x5.0' Marcy Mill is driven by a 500 H.P. A.C. Motor. The mill will rotate at 73.4% of critical speed or 14.06 R.P.M. Eight percent of the mill's volume will be occupied by steel grinding balls; 22% by pulp. The mill is designed to rotate in either direction, in order to obtain maximum lifter and liner life. The SAG mill is equipped with a trommel having ½ -inch slots for removal of oversize material at its discharge and the large or oversize material is collected and either recirculated periodically or discarded. The undersize slurry is diluted to 64% solids with the addition of hot well water or mine water to the mill discharge sump. The flow is automatically controlled utilizing data from a gamma density meter. The slurry from the mill discharge sump is pumped to hydrocyclones to classify the particles. Underflow from the cyclones, at 80% + 28 mesh, is recycled to

Jan 1, 1979

By J. S. Billheimer, B. H. Sage, W. N. Lacey

A restricted ternary system made up of n-pentane, tetralin, and a purified bitumen was investigated at 70, 160, and 220 °F. Most of the experimental observations were at atmospheric pressure or at 200 psi." However, some experimental measurements were carried out at a pressure of approximately 8000 psi. It was found that the purified bitumen was precipitated from its solution or dispersion in tetralin by the addition of n-pentane and that the separation occurred at lower weight fractions of n-pentane at the lower temperatures. The bitumen-tetralin solutions show some colloidal characteristics at temperatures below 160 °F when near compositions at which the bitumen separates as a solid phase. At states remote from the phase boundaries and at temperatures above 160 °F these characteristics become less evident. Under these latter circumstances the mixtures tend to follow the behavior of true solutions, particularly in regard to the approach to heterogeneous equilibrium. An increase in pressure appears to increase the solubility of bitumen in tet-ralin-n-pentane solutions. This effect is more pronounced at temperatures above 160 °F than at lower temperatures. INTRODUCTION Asphaltic phases of plastic or solid nature have appeared in numerous instances during the recovery of petroleum from underground reservoirs. Such depositions occurring underground appear to have caused adverse production histories for particular wells or zones. Because of this field experience, it is desirable to understand the factors which influence the formation or separation of the asphaltic phases from petroleum. The problem is unusually complex because the number of true components involved is very large and the details of the phase behavior encountered are difficult to ascertain experimentally. The literature relating to asphalts, asphaltines, and bitumen is voluminous and widespread.' Only those references which are directly pertinent to the work at hand are cited. The separation of an asphaltic phase, hereinafter called bitumen? from naturally occurring hydrocarbon mixtures has been the subject of several investigations.2'3'4'5'6 It has been found that as many as four phases4 may be produced from a crude oil by the solution of a natural gas and propane at a pressure of 1500 psi and a temperature of 70 °F. The separation of bitumen from such naturally occurring mixtures results in at least one liquid phase which is substantially free of high molecular weight components.³ The influence of the solution of lighter hydrocarbons on the separation of bitumen from a Santa Fe Springs crude oil has been investigated. The results indicate that in the case of the methane-crude oil system, the quantity of plastic or solid phase separated reaches a maximum between 0.14 and 0.19 weight fraction methane and then decreases until negligible at higher weight fractions of methane. Similiar behavior was encountered in the case of mixtures of ethane and crude oil. The decrease in the quantity of the solid phase with an increase in the weight fraction of the lighter component appears to result from the formation of an additional liquid phase6 in which the bitumen is relatively soluble. The formation of this additional phase probably occurs at a weight fraction of methane close to that at which the quantity of separated solid reaches a maximum. A comparison of the deposition of bitumen in the field with the separation of asphalts from lubrication oil has been made' and apparently the phenomena are similar. The phase behavior of bitumen also appears to be comparable to that of coal tar."' The chemical and physical characteristics of asphalts and bitumen have been the subject of extended investigations which have been reviewed in some detail by Katz.¹º The conclusion was reached that the dispersion of bitumen in a number of organic liquids was not entirely colloidal since it was impossible to isolate individual dispersed particles even with the electron microscope. However, the evidence appeared to indicate that at states close to phase boundaries the extent of the dispersion of the phases influenced the equilibrium to a greater extent than is encountered in many simpler systems. From earlier study of field samples it became apparent that the phase behavior of bitumen-hydrocarbon systems was unusually complex. It was difficult to characterize in detail the phase behavior involved in naturally occurring hydrocarbon systems, even after a relatively extended investigation. For this reason, the study of a somewhat simpler system which still behaved in a similar manner became desirable. Three major constituents were necessary as-follows: a bituminous solid, a liquid constituent which was a reasonably good solvent, and a constituent in which bitumen was largely insoluble. A sam-

Jan 1, 1949

By W. N. Lacey, B. H. Sage, J. S. Billheimer

A restricted ternary system made up of n-pentane, tetralin, and a purified bitumen was investigated at 70, 160, and 220 °F. Most of the experimental observations were at atmospheric pressure or at 200 psi." However, some experimental measurements were carried out at a pressure of approximately 8000 psi. It was found that the purified bitumen was precipitated from its solution or dispersion in tetralin by the addition of n-pentane and that the separation occurred at lower weight fractions of n-pentane at the lower temperatures. The bitumen-tetralin solutions show some colloidal characteristics at temperatures below 160 °F when near compositions at which the bitumen separates as a solid phase. At states remote from the phase boundaries and at temperatures above 160 °F these characteristics become less evident. Under these latter circumstances the mixtures tend to follow the behavior of true solutions, particularly in regard to the approach to heterogeneous equilibrium. An increase in pressure appears to increase the solubility of bitumen in tet-ralin-n-pentane solutions. This effect is more pronounced at temperatures above 160 °F than at lower temperatures. INTRODUCTION Asphaltic phases of plastic or solid nature have appeared in numerous instances during the recovery of petroleum from underground reservoirs. Such depositions occurring underground appear to have caused adverse production histories for particular wells or zones. Because of this field experience, it is desirable to understand the factors which influence the formation or separation of the asphaltic phases from petroleum. The problem is unusually complex because the number of true components involved is very large and the details of the phase behavior encountered are difficult to ascertain experimentally. The literature relating to asphalts, asphaltines, and bitumen is voluminous and widespread.' Only those references which are directly pertinent to the work at hand are cited. The separation of an asphaltic phase, hereinafter called bitumen? from naturally occurring hydrocarbon mixtures has been the subject of several investigations.2'3'4'5'6 It has been found that as many as four phases4 may be produced from a crude oil by the solution of a natural gas and propane at a pressure of 1500 psi and a temperature of 70 °F. The separation of bitumen from such naturally occurring mixtures results in at least one liquid phase which is substantially free of high molecular weight components.³ The influence of the solution of lighter hydrocarbons on the separation of bitumen from a Santa Fe Springs crude oil has been investigated. The results indicate that in the case of the methane-crude oil system, the quantity of plastic or solid phase separated reaches a maximum between 0.14 and 0.19 weight fraction methane and then decreases until negligible at higher weight fractions of methane. Similiar behavior was encountered in the case of mixtures of ethane and crude oil. The decrease in the quantity of the solid phase with an increase in the weight fraction of the lighter component appears to result from the formation of an additional liquid phase6 in which the bitumen is relatively soluble. The formation of this additional phase probably occurs at a weight fraction of methane close to that at which the quantity of separated solid reaches a maximum. A comparison of the deposition of bitumen in the field with the separation of asphalts from lubrication oil has been made' and apparently the phenomena are similar. The phase behavior of bitumen also appears to be comparable to that of coal tar."' The chemical and physical characteristics of asphalts and bitumen have been the subject of extended investigations which have been reviewed in some detail by Katz.¹º The conclusion was reached that the dispersion of bitumen in a number of organic liquids was not entirely colloidal since it was impossible to isolate individual dispersed particles even with the electron microscope. However, the evidence appeared to indicate that at states close to phase boundaries the extent of the dispersion of the phases influenced the equilibrium to a greater extent than is encountered in many simpler systems. From earlier study of field samples it became apparent that the phase behavior of bitumen-hydrocarbon systems was unusually complex. It was difficult to characterize in detail the phase behavior involved in naturally occurring hydrocarbon systems, even after a relatively extended investigation. For this reason, the study of a somewhat simpler system which still behaved in a similar manner became desirable. Three major constituents were necessary as-follows: a bituminous solid, a liquid constituent which was a reasonably good solvent, and a constituent in which bitumen was largely insoluble. A sam-

Jan 1, 1949

By Christie A. Callender, Harry M. Dahl

The Hobson uranium deposit is located in Karnes County, Texas, along the prominent south Texas uranium trend. The uranium mineralization occurs in the Deweesville Sandstone of the Whitsett Formation of the Eocene Jackson Group. The host rock is a friable, fine-grained, well-sorted, highly porous and permeable sandstone interpreted to be an ancient beach deposit. The sandstone contains significant volcanic constituents and ranges in composition from arkosic to tuffaceous. Locally, the host sandstone contains hard, dense opal cement. Bentonitic shales underlie and overlie the mineralized sandstone unit. Geometrically, the Hobson uranium-bearing zone resembles an elongated roll front type deposit. Chemical uranium values compared with gamma ray equivalent uranium values indicate that the uranium has been dissolved from the updip side and precipitated on the down- dip side of the roll front. Details of the uranium mineralization were studied using thin section microscopy, autoradiography, x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques. The uranium mineralization occurs in the pores of the sandstone, as grain coatings and as replacement of sand-size and smaller grains. It is commonly associated with pyrite and other opaque minerals. Other favored hosts for uranium (other than pore openings) appear to be clay aggregates, altered rock and glass fragments, and carbonaceous plant debris. Aggregates of coffinite were identified by XRD and SEM/EDS analyses. Some uranium mineralization also appears to be dispersed and is postulated to be adsorbed on the clay and carbonaceous matter.

Jan 1, 1985

By Alfred H. Brooks

PetRoleUm seepages are known in Alaska at four localities, all on Pacific seaboard. These, named from east to west, are Yakataga, Katalla on Controller Bay, Iniskin Bay on Cook Inlet, and Cold Bay on the Alaska Peninsula. Besides these, a petroleum residue has been found near Smith Bay on the north Arctic coast of the Territory. At Katalla, Cold Bay, and Iniskin Bay there has been some drilling for oil, and in the first field several productive wells have been opened up. Alaskan petroleum, so far as its composition is known, is a refining oil, with paraffin base and low sulphur content. Most of what is known of the geology of Alaska oil fields is based on the investigations of Dr. George C. Martin, of the United States Geological Survey. A, G. Maddren, of the same service, has recently made a reconnaissance of the Yakataga oil field. The data to be here presented are chiefly taken from the following publications: G. C. Martin: The Petroleum Fields of the Pacific Coast of Alaska, with an account of the Bering River coal deposits, Bulletin No. 250, U. S. Geological Survey, pp. 9 to 27 (1905). G. C. Martin: Geology and Mineral Resources of the Controller Bay Region, Alaska, Bulletin No. 335, U. S. Geological Survey, pp. 112 to 130 (1908). G. C. Martin and F. J. Katz: A Geologic Reconnaissance of the Iliamna Region, Alaska, Bulletin No. 485, U. S. Geological Survey, pp. 126 to 130 (1912). A. G. Maddren: Mineral Deposits of the Yakataga District, Bulletin No. 592, U. S. Geological Survey, pp. 143 to 147 (1914). Katalla Field The Katalla field is marked by a series of seepages and gas springs occupying an east and west belt, about 25 miles in length and from 4 to 8 miles wide. (See Fig. 1.) This zone skirts the north shore of Con-

Jan 1, 1915