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By D. V. Carter, F. M. Hackbusch

Beginning the year 1938, the East and East Central Texas district comprised 48 counties, which is equivalent to the Texas Railroad Commission districts 5 and 6. At the close of the year there were 46 oil and gas fields in this district. Eight other fields, seven oil and one gas, have been abandoned. Exploratory Drilling During the year, 113 exploratory wells were drilled. Nine discoveries were made, five of which proved to be oil fields, three distillate, and one gas. Completions for the district were 2043 oil wells (distillate wells included), 36 gas wells and 163 dry holes. Exclusive of the East Texas field, the Marion County extension of the Rodessa field led the district in the number of completions during the year. Production and Proration All fields in the district produced a total of 182,369,484 bbl. of oil, a decrease of 12.57 per cent compared with the 208,594,453 bbl. produced during 1937. The East Texas field produced 148,189,913 bbl., which was 81.6 per cent of the district's production for 1938. November daily average oil production for the East and East Central district was 469,102 bbl. The estimated cumulative production to Jan. 1, 1939, for this district was 1,753,894,802 bbl. It is estimated that the East and East Central district produced 38.9 per cent of the state's total production for the year, which was 468,781,632 barrels. The decrease in 1938 production, as compared to that of 1937, in this district was partly due to the Saturday and Sunday shutdowns, 71 days for the year, which is equivalent to 19.45 per cent of the year. All fields in this district were affected by shutdowns except the Texas portion of the Rodessa field, which was shut in only during January and February. Certain wells were exempt from these shutdowns because of special pro-

Jan 1, 1939

By D. V. Carter, F. M. Hackbusch

Beginning the year 1938, the East and East Central Texas district comprised 48 counties, which is equivalent to the Texas Railroad Commission districts 5 and 6. At the close of the year there were 46 oil and gas fields in this district. Eight other fields, seven oil and one gas, have been abandoned. Exploratory Drilling During the year, 113 exploratory wells were drilled. Nine discoveries were made, five of which proved to be oil fields, three distillate, and one gas. Completions for the district were 2043 oil wells (distillate wells included), 36 gas wells and 163 dry holes. Exclusive of the East Texas field, the Marion County extension of the Rodessa field led the district in the number of completions during the year. Production and Proration All fields in the district produced a total of 182,369,484 bbl. of oil, a decrease of 12.57 per cent compared with the 208,594,453 bbl. produced during 1937. The East Texas field produced 148,189,913 bbl., which was 81.6 per cent of the district's production for 1938. November daily average oil production for the East and East Central district was 469,102 bbl. The estimated cumulative production to Jan. 1, 1939, for this district was 1,753,894,802 bbl. It is estimated that the East and East Central district produced 38.9 per cent of the state's total production for the year, which was 468,781,632 barrels. The decrease in 1938 production, as compared to that of 1937, in this district was partly due to the Saturday and Sunday shutdowns, 71 days for the year, which is equivalent to 19.45 per cent of the year. All fields in this district were affected by shutdowns except the Texas portion of the Rodessa field, which was shut in only during January and February. Certain wells were exempt from these shutdowns because of special pro-

Jan 1, 1939

By D. J. Carney, J. Chipman, N. J. Grant

An absolute calibration has been achieved for sampling and analyzing liquid steel for hydrogen based on Sieverts' values of hydrogen solubility in iron. Further checks were made in nickel, iron-nickel, and 18-8 stainless melts. The sampling method was successfully applied to a large number of commercial steel melts in various types of furnaces. The concurrent problem of sample storage was also solved. THE problem of sampling of liquid steel for hydrogen is more difficult than the problem of analysis. Hydrogen has a greater mobility than any other element; it is the only element that will diffuse out of steel at room temperature. In accordance with the known relation between temperature and diffusivity, the diffusion of hydrogen is extremely rapid at the temperature of liquid steel. Consequently, in the past, attempts to quench molten steel to retain the dissolved hydrogen have not been as successful as similar attempts with nitrogen or oxygen. The retention of hydrogen is especially difficult since it will continue to escape at room temperature even if the molten metal has been rapidly quenched. The hydrogen sampling methods may be classified broadly as (1) the rapid quenching techniques which attempt to preserve super saturation and (2) those methods which attempt to collect the gases evolved as the metal freezes and cools to room temperature. With all methods of sampling but especially with the rapid quenching methods, there is also a concurrent problem of storing the sample until analysis is undertaken. The two problems are interrelated and must be considered together when discussing liquid steel sampling techniques. The major obstacle in liquid steel sampling has been that there was no way of evaluating properly the various sampling and storage techniques which have been developed. It has not been possible to compare the accuracy of the various methods. For evaluation of sampling methods some known standard is required; this may be found in the published work on the equilibrium solubility of hydrogen in liquid iron which has been determined in three separate investigations.1,2,3 The data are shown in table I. Sieverts' original method of obtaining gas solubilities involved measurement of the volume of gas required to saturate the liquid metal contained in an evacuated bulb of known volume. This procedure, improved by introduction of high frequency induction heating, has yielded reproducible results which appear to be entirely dependable. Using Sieverts' method, it has been proved for iron and other metals and alloys that the hydrogen solubility is proportional to the square root of the pressure of the hydrogen gas above the liquid, so that one may work with various partial pressures of hydrogen to put different amounts of hydrogen in solution. From Sieverts' law it is possible to know accurately what amount of hydrogen is dissolved in the liquid metal at the time of sampling. The accuracy of a sampling method may be gauged by reference to this known solubility. It was the purpose of this investigation to develop a method for sampling liquid steel and for storing the sample so that the analytical result would represent the actual hydrogen content of the metal bath. For this purpose an induction furnace was

Jan 1, 1951

By C. G. Dunn

This note describes a method for revealing micro-structures in tantalum through an {hkl} effect which was found during a study involving amorphous and crystalline tantalum oxides. Three steps are involved. First, an amorphous film of Ta2O5 is formed anodically1 on the surfaces of the tantalum. The amount needed depents on the thickness of the substrate tantalum; 1600Å of oxide, however, is generally satisfactory in the 1/2 -mil (12 µ) to 3-mil thickness range. The film at this point is uniform in color. Second, the anodized specimen is heated to 800°C in. vacuo during a period of a few minutes and held at temperature for 5 min. During such a treatment some oxygen leaves the oxide through dissolution into the substrate tantalum (e.g., at 10-8 Torr oxide films thinner than about 800 completely disappear on 5-mil strip). Considerable crystallization of the amorphous oxide also occurs adjacent to the metal/oxide interface but not throughout the oxide thickness. The thickness of oxide needed as a residue is not too critical; values between 500 and 1000Å (optical estimate') may be most useful. (The presence of a residual oxide layer after the heat treatment usually is not apparent; in fact, in most instances the surfaces have a metallic appearance. This can be the case also for thicker residual films needed in the detection of a crystalline oxide phase by surface X-ray diffraction—e.g., if the initial oxide film is 3000Å thick, enough crystalline oxide is formed for X-ray detection.) The third step eliminates the metallic appearance at the surface and reveals (or produces) a varied colored film of tantalum oxide. Two methods can be used and both will be illustrated. If the specimen is dipped in 48 pct HF for a few seconds, the tantalum is found to be covered with a multicolored oxide. Moreover the colors correlate with the grain structure of the substrate tantalum through an orientation dependence of the type illustrated in Fig. 1, where results of an orientation analysis by the Laue X-ray method have been plotted. Other film conditions would have provided a different set of colors for the same orientations. Any such correlation, however, provides a basis for a qualitative assessment of the distribution of orientations in a large sample. The cold-rolled structure of tantalum foil produced by a recrystallization anneal and a cold-rolling reduction of 95 pct is not easily obtained by usual metal-lographic methods.' The structure, however, is easily revealed by the present technique, Fig. 2. The alternative third step is to reanodize the specimen. The optical nature of the final anodic film depends on the presence of the crystalline oxide phase; color variations indicate optical thickness variations in the film. As the reanodization voltage is increased from zero, straw and light brown colors appear (as usual), followed now by variations in color from grain to grain depending on {hkl} orientation. Suitable end points, which are determined by voltage and time, are easily established. Fig. 3, for example, shows the grain structure developed in 5-mil tantalum strip during a 30-min re-crystallization and grap-growth anneal at 1800°C. An anodic film of 1600Å thickness was added prior to the special 800°C anneal. Reanodization was done at constant current density (near 0.2 ma per sq cm) in an aqueous solution of H3PO4 (0.01 pct) and was terminated after the initial brown colors were replaced by a deep blue at approximately 30 v. Although good grain contrast can be obtained with bright field illumination, even greater contrast for black and white micrographs may be obtained with polarized light, as in Fig. 3.

Jan 1, 1967

By F. F. Aplan

INTRODUCTION The production of coal is a major part of the mining industry. In recent years the production of clean coal has exceeded 600 million tons per year and is reported to have reached 660 million tons in 1977. Some data on the magnitude and utilization for the year 1975 is given in Table I. In that year 648 million tons of soft coal were produced and of this 267 million tons or 41% approximately was produced by mechanical cleaning. Of the 374 million tons of raw coal sent to the preparation plant, 28.6% or 107 million tons was discarded as refuse. In the same year approximately 6 million tons of anthracite were produced and nearly all of this was cleaned. Table I also gives coal utilization statistics for 1975. Excluding the approximately 20% that goes to the coke ovens or to export, the vast bulk of our production is used for steam power generation and a lesser amount for captive production of industrial power and process steam. While much of the nation's coal (e.g. strip mined western, sub-bituminous coal) may be removed from the ground in relatively pure form by modest selective mining techniques, other coal requires preparation in order to remove ash and sulfur constituents and produce an acceptable steam or coking coal. Preparation is often a valuable adjunct to mining in that rather non-selective, low cost, bulk mining techniques may be used underground while the preparation plant is used to reject refuse at low cost above ground. The principal reason for the use of coal preparation is to convert raw coal into an acceptable commercial product by removing the high ash and high sulfur refuse material.

Jan 1, 1979

By E. P. Mathewson

In a discussion of a paper on The Basic Process as Applied to Copper Smelting, by Percy C. Gilchrist, read before the Society of Chemical Industry, London, Jan. 5, 1891,' Prof. W. C. Roberts-Austen asked Mr. Gilchrist whether he thought that the substitution of a basic lining for acid lining in the Manhks process would afford anything like the service which it had been shown to render in the metallurgy of iron. Claude Vautin stated that he had experimented for over two years. with basic linings for Bessemer converters for copper mattes at Cobar, but had given up the attempt on the score of cost. Mr. Gilchrist in his reply stated that he did not believe in applying any system of Bessemerizing to copper. About the time of the presentation of the paper mentioned,Hermann Keller, Superintendent of the Parrot smelter, in Butte, was experimenting on a large scale with converters lined with magnesite brick. He gave up the idea on account of the cost of linings and because no particular advantage was observed. My belief is that his tuyeres and converters were too small. A short time afterward similar experiments were tried at the Great Falls plant of the Boston & Montana Co., and at the Old Works of the Anaconda Copper Mining Co. in Anaconda. These were abandoned on the score of cost and the lack of advantages. The same cause of failure, in my opinion, holds here. The Anaconda Copper Mining Co., however, adopted the magnesite brick lining for its tilting casting machines. Fig. 1 is a view of the first tilting furnace casting copper. It was made from an old Brueckner roasting cylinder. Fig. 2 shows an elevation and vertical and horizontal longitudinal sections of the second tilting furnace, built in 1897.

Jan 1, 1914

By K. B. Nowels

DATA pertaining to pipe line flow for both oil and gas in horizontal or nearly horizontal pipe lines are both extensive and accurate. However, the pipe formulas used to determine pressure drop for flowing fluids (liquids and gases) under conditions of horizontal flow are not generally applicable to flowing oil and/or gas wells. Except for some data developed in small laboratory set-ups, little or no information was available concerning flow of oil and gas mixtures in vertical pipes, when, in 1928, the writer began the development of a method for computing pressure drops in the pipes of flowing oil wells, as outlined in this paper. In 1929, Uren1 presented some findings based on laboratory experi-ments in which vertical flow of an extremely heavy crude oil was induced, by means of air through a 2-in. pipe, 41 ft. long. The friction factors derived from the experiment, as well as values for pressure drop per 100 ft., are not believed satisfactory in their application to flow problems in the field. Versluys,2 also in 1929, presented a mathematical development of the theory of flowing oil wells, and in 1930, gave a companion paper3 setting forth some principles governing the choice of length and diameter of tubing in oil wells. Since the termination of the study presented in this paper, another. valuable contribution pertaining to the problem, of vertical flow was made by Moore and Wilde.4 Although there were writings dealing with the principles of the gas-lift, a search of the available literature indicated that specific information on vertical flow was lacking with the exception of the writings of Uren, Versluys, and Moore and Wilde, to which reference .has been made.

Jan 1, 1932

By C. G. Dunn, M. Sharp

HE orientations of 137 crystals of copper pro-T duced by secondary recrystallization in a cube texture matrix have recently been obtained. Although the crystals were not prepared for the purpose of determining a secondary recrystallization texture, the orientations obtained proved to be rather interesting, as they confirmed, in part, published results and also disclosed additional preferred orientations in the texture. The investigation of Dahl and Pawlek,&apos; Bowles and Boas,&apos; and Kronberg and Wilson3 showed respectively that the orientations of secondary grains growing in a cube texture matrix were related to those of the primary grains by a rotation of approximately 30" about [001], the rolling direction, by 30" about a <111> direction, and by either 22" or 38" about a <111> direction. Kronberg and Wilson also obtained a component of the texture similar to that of Dahl and Pawlek except the angle of rotation about [001] was 19". When the cube texture matrix was deformed a small amount, Kronberg and Wilson also obtained large grains on subsequent annealing corresponding to a rotation of 15" about the normal to the sheet, but these grains should not be classified as secondary recrystallization grains since they were produced subsequent to mechanical straining. The particular texture obtained, of course, depends on the composition of the copper and the processing schedule employed, since these factors markedly affect the primary recrystallization texture and the sharpness of any cube texture produced. In the present investigation, pieces of OFHC copper in the form of M in. round bars were cold forged to a thickness of about 0.40 in., annealed 1 hr at 350°C in an atmosphere of hydrogen, and cold rolled crosswise to a thickness of 0.200 in. These pieces were given a penultimate anneal of 1 hr at 350°C in hydrogen and a 90 pct cold-rolling reduction lengthwise to a thickness of 0.020 in. Indentations generally were put in one end of the as-cold-rolled strips to promote earlier formation of secondary grains.

Jan 1, 1953

By F. E. Lucas

This paper is offered with considerable diflidence, since some of the statements made may not agree with the opinions of other members of the Institute. What I give is the result of some years of experience in the operation and construction of coke-ovens, and observation of plants in America and Europe. Although my title is " The Manufacture of Coke," I have found it impossible to do justice to the subject without touching on a number of points which, while not strictly involved in the making of coke, yet are of paramount importance from an economic standpoint. There are, indeed, many points of interest, on each of which a separate paper of considerable length might be written, but the scope of my paper will permit me only to touch lightly some of them, in the hope that what I say will promote a full discussion on the whole question. Those of us who are interested in the manufacture of coke are under an obligation to the American Institute of Mining Engineers, which has opened its meetings to the discussion of this subject. I do not believe that there is any question to-day more worthy or more in need of discussion. When geologists and mining-men tell us that, at the present rate of consumption, our coal-fields will be exhausted in a few generations, me should welcome any means that will conserve these deposits as far as possible, and give us the greatest amount of heat or power from every ton mined. I shall try to show that much can be done in this direction through the by-product coke-oven, and that it should stand second to none as an economic factor in the industrial world. I shall here deal exclusively with the by-product oven, except for the comparative statement I hare prepared, showing the saving to be effected by coking in by-product instead of beehive orens. It should be borne in mind that this comparison

Jan 1, 1913

E. S. BARDWELL,* Great Falls, Mont. (written discussion ?).-There are several points in. connection with the manufacture of ferromanganese in the electric furnace which it seems to me. might prove of interest in this connection. Recent observation of a, number of electric furnaces varying considerably in size and transformer capacity, and all working under the same conditions, shows the small furnaces to be much more efficient in operation than the large furnaces. The furnaces examined were all of the same type. The crucibles consisted of tanks varying in size from 71-z by 15 ft. by 4 ft. deep, to 12 by 20 ft. by 9 ft. deep, with linings formed of carbon electrode butts. The smaller furnaces had transformer capacity rated at 1500 k.v.a.; the largest furnace had a transformer rated at 3000 k.v.a. All of the furnaces were operated on three-phase, 60-cycle current, the three electrodes being in a straight line. The voltages varied from 65 volts in the smaller to 100 volts in the larger furnaces. The charges consisted of manganese ore, coal, iron turnings, and limestone in proper proportions. The small furnaces, operating at low voltage, were making good recoveries. The slag loss was low and the volatilization loss almost nil. The larger furnaces, operating at higher voltages, showed increased loss of manganese in the slag and greatly increased volatilization loss when working on the same charges as the smaller furnaces, or on charges similarly calculated. The exact reasons for this state of affairs are difficult to state; a number of factors probably contribute to the results obtained in the large furnaces. First as to the effect of the higher voltage on manganese content of the slags. Increasing the voltage of the furnaces apparently tends to promote irregular working. The current takes the path of least resistance; this means superheating in certain areas in the crucible and insufficiently high temperatures in adjoining areas. The partially reduced manganese in the cooler areas passes into the slag and escapes further reduction.

Jan 11, 1918

By Robert D. Pike

IN November 1939, on behalf of the Harbison-Walker Refractories Co., the author undertook the study of the problem of utilizing the dolomite of northwestern Ohio for the manufacture of calcined magnesia suitable for use in refractories. Grateful acknowledgment is made of the unfailing assistance and encouragement throughout this work from the executive and technical staff of Harbison-Walker Refractories Company. The dolomite of the Niagara formation that is exposed or near the surface of a wide area in northwestern Ohio1 constitutes a vast supply of almost pure dolomite. It offers a virtually unlimited supply of cheap raw material of uniform dependable analysis for the manufacture of magnesia. A typical analysis of dolomite from the vicinity of Luckey, Ohio, follows: [ ] Brines containing magnesium chloride or sea water can be reacted with calcined dolomite to produce magnesia.2,3 In such reactions the MgCl2 of the brine supplies some of the magnesia and the amount of dolomite required is thereby reduced by an equivalent amount, but brines of commercial importance containing magnesium chloride are some distance away from the purest grades of the dolomite of northwestern Ohio. It was decided therefore to concentrate upon the development of a suitable process for separating the lime and magnesia of dolomite, depend¬ing upon the dolomite itself as the sole source of magnesia. This would make it possible to place a plant at the dolomite quarry, thus eliminating the cost of transporting the stone and also rendering the calcined magnesia available at a most convenient production point, considering the cost of delivery throughout the steel industry. The selection of a process depending solely upon the dolomite as a source of magnesia also necessarily entails production of the lime content of the dolomite as a by-product. It was recognized that if such a lime by-product could be produced in a suitable form, a plant location in northwestern Ohio would also be advantageous for marketing the lime. The problem, therefore, was the discovery and development of a low-cost process for separating the magnesia and lime of the dolomite of northwestern Ohio and producing each in a form relatively free from the other, and meeting the respective requirements of established markets. A satisfactory solution of this problem has been found, and it is the

Jan 1, 1947

By W. A. Walker, G. W. Ostroot

An increase in the number of deep wells being drilled where extreme bottom-hole temperatures are encountered, and the anticipated drilling of wells where temperatures in the range of 500°F or higher may occur, has brought about a comprehensive investigation of cementing materials and of the techniques involved in their proper usage at these elevated temperatures. Included are developments in cements, retarders, weighting materials and other cement additives which make it possible to formulate a variety of compositions to help resolve the cementing problems of these extreme well conditions. The problems associated with the selection and testing of cements are discussed, and a resume of field results is included. Previous studies on strength retrogression indicate that caution should be exercised in the selection of a cementing composition for use in high-temperature wells. It now appears that, by the addition of silica flour as a stabilizing additive to certain cements, compositions covering a wide range of slurry densities can be designed to meet extreme well conditions without strength retrogression. Improvements in cement retarders make it possible to produce a four-hour thickening time at static temperatures up to 500°F. This temperature is considerably higher than conditions presently being encountered in drilling and completion work. Inert weighting materials, used to produce 20-lb/gal or heavier cement slurries, are reviewed. INTRODUCTION As the search for oil continues, the number of wells being drilled to depths of 10,000 ft or below has continued to increase over the past decade. During 1959, there were 50,893 wells drilled in the United States for a total of 209 million ft of hole. Of this total, approximately 4.45 per cent were drilled below 10,000 ft and 0.30 per cent below 15,000 ft, with a record depth of 25,340 ft recorded (Table 1). With the drilling of this record-shattering hole comes the question, "How deep can wells be drilled?".&apos; Limitations with respect to equipment (surface and subsurface), cementing materials and techniques would cause some concern; however, a panel of experts have agreed that the U. S. oil industry has the equipment and know-how to drill a 50,000-ft hole. The greatest deterrent would be the 700°F temperature they would anticipate encountering at this depth. Although the number of wells drilled under what is generally considered hot-hole conditions (230°F and higher) has been relatively high, each well often presents distinctly individual problems and requires separate consideration and selection of special materials, techniques and equipment. At the present time there are over 30 additives and special cements available for use in "tailoring" a cementing composition for a specific well. It is not uncommon to use three or four different additives with the basic cement to produce the desired slurry characteristics. A generally accepted procedure is to make laboratory tests on selected cementing compositions prior to pumping them into wells deeper than 12,000 ft, or where static temperatures are in the range of 260°F or higher. In some instances, it is recommended that laboratory tests be made where less severe well conditions are encountered. Prior to selecting a cementing composition for a particular well, key personnel representing the operator, drilling contractor and service company should meet to determine that each individual is acquainted with every detail which might influence cementing results and to discuss the execution of the job. For cementing hot-holes, a number of factors must be evaluated before proceeding with the operation. Consideration must be given to the following. 1. Thickening time—The slurry must remain fluid for a sufficient length of time to allow displacement down the casing and up the annular space in a primary cementing job or, in squeeze-cementing, adequate thickening time for both the build-up of a satisfactory squeeze pressure and the reversing out of excess cement. The thickening time of standard retarded cements will often be too short under extreme temperature conditions, thus involving special formulations and requiring laboratory tests to determine the proper amount of additional retarder to obtain the desired pumpability.

By W. White, C. S. Barrett, R. M. Mueller

THIS communication reports film-recorded low-energy (-100 kev) proton blocking patterns&apos;-3 for hcp and wurtzite crystals. In particular the sequence of relative line intensities* (corresponding to planar blocking) of common hcp metals is compared with those of the wurtzite semiconductors CdS and CdSe. The results show that the sequence is characteristic of structure. For closely similar structures such as those of CdS and CdSe, differences of line intensity attributable to the difference in atomic number, 2, of the scattering centers may also be seen. The apparatus and techniques used in this work were identical with those reported previously in a study of cubic systems.3 All metals were given standard metal-lographic etches, and the semiconductors cleaved, immediately prior to introduction to the vacuum system. Fig. 1 shows the unit cell of the wurtzite structure, and the geometry used to obtain the [1120] and [0001] patterns of Fig. 2. The axial ratio, c/a, for all ma- terials of Fig. 2 is close to 1.63. The patterns are then directly comparable in linear dimensions inasmuch as they have been reproduced at the same overall magnification of the patterns. (Overall magnification is proportional to the product of film-to-target distance and printing magnification. Thus the 1/6-in.-diam beam passage hole in the center of the film need not appear of uniform size in the prints.) The patterns for a given orientation, though similar

Jan 1, 1970

By J. A. Clum, R. W. Heins, T. D. Tiemann

The use of Na-montmorillonite clay hinders (Western Bentonite) in the pelletizing of iron ore concentrates is well established as is the idea that alternative binders must be found. 1-6 This note summarizes work done7 in evaluating a Wisconsin montmorillonite clay binder. The clay occurs in irregualr beds overlying the Prairie du Chien Dolomite and the St. Peters Sandstone near Hersey, St. Croix County. The raw Wisconsin clay contained 65% quartz and 35% clay minerals. The Na20to CaO ratio was 0.234. Suspension viscosity tests of the raw clay gave results only slightly better than water alone, even after treatment with activator materials. Sedimentation treatment reduced the quartz in the decantate to 5% after 240 min (four hours). Twenty minutes of sedimentation produced a decantate with 27.5% quartz which was found as effective as the 5% quartz decantate in pelletizing behavior. The 20 min decantate was used in subsequent tests. The decantate was filtered and dried at 110°(230°F). The minus 200 mesh portion of this was added directly to the magnetite concentrate. Pellets were made in a laboratory sized disc pelletizer from pastes consisting of ore concentrate, balling water (9%) and binder (clay, or clay + resins, or resins). The pastes were premixed in a Waring blender. The binders were: (1) 1% of a commercially used Western Bentonite; (2) 1 % or 3% of the Wisconsin clay (raw, or 20 min decantate); (3) 20 min decantate washed with activator solutions, (to exchange Na for Ca in the clay); (4) decantate with activator added in the balling water; (5) decantate with organic resins; (6) organic resins. Measurements of the 0.46 m (18 in.) Green Drop Number, the Dry Strength and the Fired Strength (fired at 1260°C (2300°F) for 30 min) were made. The dry and fired compressive strengths were determined on an Instron testing machine using a C-load cell and a F-load cell, respectively. The cross-head speed was 0.004 m/sec (0.1 in./min) for both. The results of each measurement were averaged for 15 pellets. A summary of those results is presented in [Table 1]. More detailed results and procedures are presented in another report.7 In addition to the effects on pellet strength due to various binders the effect of varying magnetite concentrate characteristics is noted in [Table l]. There, a few comparative data are shown for Cornwall, PA Magnetite, which has a generally liner particle size than the Black River Falls magnetite which was used for most of the tests.

Jan 1, 1979

By O. N. Cole, R. E. Davis, T. D. Brotherton

Pvfoperties of rubidium and cesium are compared with those of other alkali metals. Methods for the preparation of rubidium and cesium metal are reviewed briefly, ad hazards and safety precautions required in handling rubidium and cesium metal are described. SimPle methods for handling laboratory quantities of elemental rubidium ad cesium under oil and under argon are illustrated. CESIUM and rubidium were both discovered by Bunsen and Kirchoff in the years 1860 and 1861. Cesium was discovered while Bunsen and Kirchoff were making a spectrographic study of spring water from Durkheim, Germany. It was the first element discovered by this technique. The element was given the Latin name "caesius" for sky blue because of the color it imparted to flames. Elemental cesium was first prepared by Setterberg in 1881 through electrolysis of a molten mixture of cesium and barium cyanides.&apos; In 1861, Bunsen and Mirchoff discovered rubidium while making a spectrographic study of the alkali content of lepidolite ore from Saxony. Two prominent dark red lines appeared in the spectrum and so the element was named "rubidius" or dark red. In 1861 Bunsen and Kirchoff first prepared elemental rubidium through the electrolysis of molten rubidium chl~ride.~ The alkali metals are very similar in their chemical and physical properties. They are the most active metals, and all exhibit a single oxidation state of one. They are so reactive that they are never found in nature in the elemental state. The reactivity of he metals increases with atomic number. Rubidiurn and cesium ignite spontaneously in air and react explosively with water. This extreme reactivity makes necessary special equipment and techniques for the safe preparation and use of the metals. The cation: of Group IA can be separated from the metallic cations of other groups with relative ease, but the separation of the individual alkali cations is much more difficult because of their close chemical similarity. This close chemical and physical similarity of alkali metals can be inferred from the atomic radii, oxidation numbers, and ioni-zation potentials shown in Table I. A difficult but the most practical physical method of separating the elemental alkali metals from one another is by distillation. Only lithium has a boiling point sufficiently far-removed from the boiling points of the other alkali metals to make this method of separation feasible without elaborate and expensive equipment. This method is not used, however, for lithium because it possesses sufficient chemical dissimilarity from the other alkalies for it to be separated relatively easily as lithium hydroxide monohydrate or as lithium carbonate. Francium, the last member of the group, has no known stable isotopes. The naturally occurring

Jan 1, 1962

THERE is at least one concrete indication that Soviet Russia&apos;s two most important iron ore producing centers are seriously depleted. While keeping in mind Russia&apos;s penchant for reverse propaganda, one piece of evidence indicates that Magnitugorsk in the southern Urals and Krivoi Rog in the Ukraine have been mined to a point where lower grade ores are being recovered. An article in Pravda, Soviet newspaper, by I. P. Bardin. a Russian metallurgist, says that ore presently mined must undergo an expensive enriching cycle before it can be used in blast furnaces. Com- pounding Russian metallurgical troubles is the low quality of coking coals. High ash and sulphur content typifies the coal Badin talks about. Coal from the Ukraine, Eastern Siberia, Kazakhstan, and the Far East requires extensive treatment before it can be used, according to the article in Pravda.

Jan 7, 1953

By H. C. George

With a growth of 718 per cent in the petroleum industry from 1901 to 1931, there was a corresponding increase in the demand for technically trained men in the industry. This was first met by increasing numbers of college graduates from the old established courses in chemistry, geology and engineering. However, a need began to be felt for scientists and engineers specially trained for the petroleum industry. In 1912 the University of Pittsburgh established the first department in any university in the world that offered major work in petroleum engineering and petroleum geology. In Europe, the first major work in petroleum engineering was offered in England in 1913 at the University of Birmingham. The University of California and Stanford University offered major work in petroleum engineering in 1915. Since that time at least 10 other American universities and colleges have offered major work and at least 12 others are now offering some courses dealing with petroleum and the petroleum industry.

Jan 1, 1934

By Chi-Yuen Wang, Chaw-Long Chu

The time-dependent volumetric constitutive relation for a San Andreas fault gouge and a consolidated kaolinite are experimentally determined at confining pressures to 200 Mpa, under creep condition and at ultrasonic frequency. At any given pressure, the bulk modulus determined at 1 Mhz frequency is identical to the "elastic" modulus determined at a stepwise change of pressure. After the pressure change, there occur a time-dependent change of volume and thus the effective bulk modulus. The constitutive relations may be modeled by a standard linear viscoelastic medium with pressure-dependent moduli and viscosity. For the San Andreas fault gouge, viscosity increases from 2x10 13 poise, at 17 Mpa, and 10 14 poise, at 100 Mpa. For kaolinite sample, the corresponding values are 3x10 12 poise and 10 13 poise. These results imply that both stress and pore pressure in fault zones may show time-dependent variations in response to a change of state of stress, such as that occurring after an earthquake.

Jan 1, 1982

By T. P. Meloy

In a recent paper, Gaudin and Meloy1 derived a size distribution function for single, impact fracture. Mular2 extended the use of this size distribution to describe the output of carefully controlled grinding experiments. As it stands, the function is difficult to compute. Consequently, a series of tables of the function are presented below: where M(x) is the cumulative fraction finer than size x when x is particle size. Weight percents are tabulated for the single parameter, r, in three different size ranges: from 0 to 1, from 1 to 10 and from 10 to 100. Tables I, II and III are cumulative percent finer and Tables IV, V and VI are for weight percent passing screen size x, retained on the screen below. A number of conditions from the table are plotted in Figs. 1 and 2. Fig. 1 is a plot of the cumulative percent finer vs. size, and Fig. 2 is the weight per-

Jan 1, 1963

By Charles T. Holland, David A. Olsen

Considerable work has resulted in the development of a formula by which the strength of coal pillars for an L to T ratio of up to 12 may be estimated. One of the factors involved in this formula is the coefficient of friction between the coal pillar and the adjacent rock with which it is in contact. This paper presents the results of studies on sandstone, limestone, shale and coal and the coefficient of friction between coal and the other three under wet and dry conditions. With the coefficients of friction thus determined and the use of results obtained earlier by Meikle and Holland, it seems probable that coal pillar strength may be more closely estimated. Several investigators1-3 have found that the com-pressive strength of cubical coal specimens can be correlated by an equation such as

Jan 1, 1969