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By Peter F. Weiss

INTRODUCTION Austro-American Magnesite Co. of Radenthein, Carinthia, Austria, is a wholly owned subsidiary of General Refractories Company, Bala Cynwyd, USA, and has been incorporated since 1908. The raw material basis is the magnesite mine on Millstatt Alp, located in the mountains near Radenthein at an altitude of 1500 m above sea level. The mined crude magnesite is crushed in a surface crushing plant to minus 35 mm and consequently hauled to the processing plant in the valley by means of a cable conveyor of 7.5 km length. The annual production of 350,000 mt is accomplished with 20 supervisors and 122 workers (of those 60 are in the mine). The labor requirement for block caving is 0.2 man hr/mt, corresponding to an output of 40 mt/man/ shift. GEOLOGY The rock in this area mainly consists of crystalline type schist. There are mostly coarse crystalline garnet mica schists with varying mineral concentrations, and to a lesser degree, some deposits of amphibolite and marble. This petrographically rather homogeneous rock is divided into numerous different tectonic units (covers and scales). The magnesite deposit itself is a foreign body that also has been tectonically inserted. The ore body has a length of 600 m, is 450 m deep, and has a thickness of 60 m on average, varying substantially however, The contact with the accessory rock is very precise. The deposit 1 = ore body, 2 = previous open pit, 3 = caved in area, 4 = block under excavation, 5 = land slide consists of coarse crystalline magnesite in excess of 90 per cent. The few impurities consist of dolomite and talc. The lower part of the deposit is inclined parallel with the schists at approx. 40 degrees. In profile it can be seen, however, that the upper part of the deposit has been tilted over. This is a result of a post-glacial land slide reaching from the bottom of the valley at 1400 m above sea level to the peak of the mountain at 2100 m above sea level. Due to this land slide, with horizontal movements of up to 100 meters, as well as older tectonic events, the rock was crushed to a vast extent. Through mining, the land slide was reactivated; about 40 million cubic meters of rock slowly flow downhill almost like a plasticized mass. Near the surface, the rock is completely crushed and resembles a glacier rupture zone. This renders the originally impermeable rock completely water permeable so that practically all of the annual quantity of 1000 to 1100 mm of precipitation permeates the rock and flows down into the mine. The carbonate rock turns into the preferred aquifer. From 1700 to 2600 cubic meters of water have to be pumped from the mine daily. On one hand, additional problems are caused by the water in the mine, on the other hand we have learned to make use of the down- hill pressure forces to improve the crushing process during block caving. The boundary of the downhill shearing zone moves downward as mining goes deeper.

Jan 1, 1981

By H. C. Gatos, J. T. A. Pollock, V. Sadagopan

PREVIOUS investigations on the effect of neutron irradiation on the superconducting properties of bulk transition metals indicated that little or no change occurred in poly crystalline disordered materials, particularly if cold-worked prior to irradiation. Only the superconducting properties of ordered intermetal-lic A15 compounds were found to be sensitive to irradiation, and the observed reduction in Tc and increased magnetic hysteresis or critical current densities were attributed to the introduction of flux pinning vacancy clusters and disorder in the lattice. Since the former would also be expected to be present after irradiation in disordered alloys, the general conclusion was that the disordering effect of the irradiation was the primary reason for the changes observed. The present note reports some unusual effects of neutron irradiation on cold worked Nb(Cb)-Ti-V alloys. Specimens with nominal composition as given in Table I were prepared by repeated arc melting, taking the usual precautions, and homogenized at 1000°C for 24 hr prior to a reduction of 15:l by cold rolling. Samples of size 1 by 1 by 25 mm were sliced from the rolled strips. The sarmples chosen for irradiating were sealed in a cadmium tube (wall thickness 1 mm) prior to exposure in a fast neutron flux of 3.7 x 1019 neutrons per sq cm in the swimming pool reactor of Union Carbide Corporation&apos;s Sterling Forest Reactor. During irradiation the temperature of the samples was maintained below 70°C. The irradiated samples were stored at room temperature for approximately 1 year allowing the radiation levels to reach a safe handling value. Tc measurements were made employing a self-inductance coil technique. Jc data at 4.2"Kwere obtained using a four lead resistivity method. The latter measurements were made at the Francis Bitter National Magnet Laboratory by setting the perpendicularly applied field and increasing the direct current through the sample until a potential of about 10-6 v was detected. Tc values for the nonirradiated samples are listed in Table I together with the change in Tc after irradiation. A decrease in Tc of 0.25 or 0.3"K was measured for three of the four samples, the exception being the Nb-30 at. pct V-20 at. pct Ti alloy which showed a decrease of 0.5K. Jc vs applied field data are plotted in Fig. 1 for the Nb-20 at. pct V-30 at. pct Ti alloy. These curves are typical of the four alloys and surprisingly indicate that a degradation occurred in all the samples after irradiation. Hc2 values, obtained by extrapolation to zero current, are 8 to 15 pct lower than those measured for the nonirradiated specimens. The reasons for the degradation of Tc and jc ob-served in the alloys on exposure to neutron irradiation are not immediately apparent. The temperature at which the samples were maintained during bombardment (<70°C) and stored (20°C) make it highly unlikely that any significant change in the dislocation density of the materials through thermally activated migration and annihilation would occur. The explanation must lie in the type of damage produced by the bombardment. McEvoy et a1. reported no change in superconduct-

Jan 1, 1970

By J. P. Hammond, C. J. McHargue

THERE have been no publications on the wire texture, on the cold-rolled sheet texture, nor on the recrystallized sheet texture of vanadium. Since it has a body-centered cubic structure, it would be expected to show strongly preferred orientations such as are found in iron&apos; and molybdenum.&apos; The wire textures of body-centered cubic iron,3 tungsten," molybdenum,5 antalum,6 iobium,6 and brass6 have been found to have [110] directions lying parallel to the wire axis. Wires of iron,&apos; containing 1.95 pct V or 1.95 pct Si,7 and steel8 retain their texture upon recrystallization. Molybdenum9 and tungsttln&apos; wires retain their texture after recrystallization at low temperatures. A [loo] recrystallization texture has been reported for mo1ybdenum9 and for a Fe-Ni alloy (53 atomic pct Ni).10 The cold-rolled sheet texture for iron,&apos; mild steel," and molybdenum chiefly one in which the [110] directions lie parallel to the rolling direction and the (100) planes lie parallel to the rolling plane with a deviation from this position chiefly about the rolling direction as an axis. This paper presents the cold-rolled and the re-crystallized wire textures, and the cold-rolled and the recrystallized sheet textures for vanadium. The results show that the textures in vanadium are not significantly different from those reported for other body-centered cubic metals. The vanadium used in this investigation was the so-called "ductile" vanadium which has a nominal composition within the following limits:12 0, 0.05 to 0.12 pct; H, 0.001 to 0.004; N, 0.02 to 0.04; C, 0.03 to 0.07; and V, 99.8 to 99.9. The wires were formed by rolling annealed rods of 0.280 in. diam to 0.028 in., a reduction in diameter of 90 pct. The wires were then electrolytically etched to 0.005 in. diam and used as such for specimens. Annealed sheet was reduced 95 pct in thickness from 0.100 to 0.005 in. with a two-high, 4-in. diam mill using reductions no greater than 10 pct per pass. In order to avoid temperature effects, the sheet was allowed to cool between passes. X-ray specimens were made in the form of posts from the sheet. The sheet was mounted in a fixture and the edges were polished using metallographic technique. Each edge was alternately polished and etched during the last stages in order that all worked material would be removed. These post specimens were approximately square in cross-section. The specimens to be recrystallized were wrapped in tantalum foil, sealed in evacuated quartz tubes, and annealed at 1600°F. The X-ray data were obtained from transmission shots made with a 0.030 in. pinhole camera, and molybdenum radiation with a zirconium filter inserted between the specimen and film. The grain size was sufficiently small in both the cold-worked and recrystallized material to give satisfactory results with the specimens stationary. In order for the wire texture to be determined, transmission X-ray patterns were taken with the

Jan 1, 1953

By Alec M. Crowell, J. W. Sanders

While the production of crude oil and condensate in South Arkansas increased only 1.7 per cent over the 1940 figure, complete utilization of gas produced with the oil and condensate, and heretofore wasted, was beginning to be evidenced. There were 26,229,264 bbl. of oil and condensate produced in South Arkansas during 1941, as against 25,790,380 bbl. for the year 1940. (Fig. I.) Since 1936, deep producing sands have been discovered in 18 fields and during that period only 40 per cent of the total state production has come from Upper Cretaceous formations while 60 per cent came from the Lower Cretaceous and Jurassic formations. The gas produced with crude oil and condensate from the latter formation contains large quantities of hydrogen sulphide, the maximum being 6900 grains per 100 cu. ft. in the Patton pool of Lafayette County. Gas Utilization During the latter part of 1940 and the early part of 1941, pilot plants were placed in operation to determine whether the hydrogen sulphide and deleterious material in South Arkansas gases could be removed economically. The Federal Government desired to build a large aluminum plant in the Ouachita Valley and was seeking cheap fuel for the generation of electricity. The fact that the gases were produced with appreciable quantities of crude oil and condensate made it available at a very low price, since the state&apos;s conservation law prohibits the flaring of any gas. As a result of these experiments the first large-scale unit for the processing of gases containing hydrogen sulphide was placed in operation on Sept. I, 1941. The plant is in the Magnolia oil field, Columbia County. It processes residue gas from the Shell Oil Company&apos;s gasoline plant in that field and also raw gas from the Village field, 6 miles east of the Magnolia field. The gas entering the desulphuri-zation unit is laden with approximately 1400 grains of hydrogen sulphide per 100 cu. ft. and is stripped to a content of 4 grains per 100 cu. ft. The capacity of the plant is 15 million cu. ft. of gas treated daily under a pressure of 160 lb. per sq. in. The cost of treatment, exclusive of depreciation, is appreciably less than I per 1000 cubic feet. Two other plants of much greater capacity have been announced and priorities have been granted, which should bring the total amount of gas treated to 150 million cu. ft. daily. The gas to be treated will have a maximum hydrogen sulphide content of 4500 grains per 100 cu. ft. and will be processed under a pressure of 600 lb. per sq. in. These developments are something entirely new in field practice for the industry. The fact that this heretofore wasted gas is available at very low cost has led to the location of some eight war industries within the state, in addition to the alu-minum plant. Recovery OF Sulphur The Susearch Corporation and the Southern Acid and Sulphur Co. placed in operation during 1941 pilot plants to de-

Jan 1, 1942

By Alec M. Crowell, Harry P. McClintock

Production of oil and gas condensate from the 45 oil and gas fields of South Arkansas increased for the eighth consecutive year, the production for 1943 being 27,605,647 bbl. Six new pools were discovered during 1943, bringing the state&apos;s crude oil and condensate reserve to 475 million barrels, a net increase of 70 million barrels for the year. The gross increase in proven reserve was 98 million barrels, from which, of course, is subtracted production of approximately 28 million barrels to reach the net figure of 70 million barrels. There were 35 more wildcats in 1943 than in 1942, and 29 more wells were drilled in fields of the state. Sixteen companies operated exploratory crews during the year for a total of 677 crew weeks, divided as follows: 563 weeks seismograph, 111 weeks gravity and 3 weeks core drill. There was a decided increase in gravity work and a decrease in seismic work. The year started with 15 seismic crews and ended with 5 seismograph and z gravimeter crews. Geologically, it is interesting that the number of wells bottomed in Gulf, Comanche, and Jurassic strata were near equal for the year 1943. During 1942 Jurassic was much higher than the other two. However, Jurassic still led in wildcats for the year 1943. Abandoment of wells in the stripper areas of the state reached about the same figure for the year 1943 as for the year 1942; that is, 145 wells were permanently abandoned. However, 243 wells were drilled in 1943, as against 184 for the previous year. The completions for the year were divided into 103 dry holes, 137 oil and condensate wells and 3 dry gas wells. Among new developments perhaps the most significant was the pressure-main-tenance project for the Midway field of Lafayette County, which is utilizing fresh water as the maintenance medium. This is the first fresh-water pressure-maintenance operation during primary production of an oil field in the United States. The operator of the project, Barnsdall Oil Co., estimates that the ultimate recovery of oil from this field will be increased from 32.5 to 65 million barrels. The Midway pool is of the dissolved-gas type, but a similar project is getting underway for the Magnolia field, Columbia County, a pool of the gas-cap and water-drive type. Dual completion of wells, on concurrent production from two productive zones through a single well bore, became common practice in South Arkansas during the year. As the year ended, some 50 wells had been dually completed and it was estimated that the first 37 of these wells represented a saving of more than 2 1/4 million dollars and a saving in steel of 7000 tons. The majority of the wells dually completed were those reaching depths in the neighborhood of 9000 ft. below the surface and initially productive there. Selective completion at lesser depths in the same well bore proved mechanically feasible and economically sound. The year was marked by the successful completion and placing into operation of three large natural-gas desulphurization

Jan 1, 1944

By C. E. Westley, R. R. Beebe

Recent works by Plaksh et al.,1,2 Glembotsky,3 and others have renewed interest in the effects of oxidation on the surface activity of the sulfides. Since considerable supporting data are available on galena-potassium ethyl xanthate, this system is being studied at South Dakota School of Mines and Technology by contact angle measurement, using the technique of McGlashan and McLeod.4 The contact-angle method is well adapted to investigation of the influence of small amounts of oxygen on the establishment of a stable contact angle on galena in potassium ethyl xanthate solution. Samples of massive galena containing less than 0.001 pct Cu, 0.001 pct Ag, and 0.01 pct Zn are mounted in castable plastic and ground and polished manually in a glove box containing the desired proportions of oxygen and purified nitrogen. Oxygen and nitrogen contents of the test atmosphere are determined with an Orsatt analyzer. In this way a reproducible surface is created in contact with whatever oxygen concentration is desired. Water and all reagents are prepared and stored in the test atmosphere. An absorbent is used to control carbon dioxide that might be present. Final polishing is done with levigated alumina on a glass plate. The prepared sample is placed in the test solution and transferred to the contact angle apparatus in a sealed box, and the test is conducted while both sample and solution are maintained under a slight positive pressure of the test atmosphere. Table I gives the results of contact angle measurements made at various 02-Nz concentrations.5 Each value of contact angle is the average of at least six individual measurements made with different bubbles at different locations on the sample surface. A period of 20 to 25 min has been found by preliminary tests to be sufficient to permit develop- ment of maximum angle, and all measurements are made after at least this much time has elapsed. Exposure of prepared samples to pure water under the test atmosphere before exposure to the xanthate results in a small but measureable and consistent reduction in contact angle. This is particularly true in the oxygen-deficient atmospheres; for example, at 2.2 pct O2 such water contact reduces the average angle about 8" from that obtained by immediate testing in xanthate. The general trend of increasing contact angle with increasing oxygen concentration corresponds to the results of Plaksin et a12 The absence of diminish-ment of contact angle at very high oxygen concentration has been attributed to the high concentration of xanthate per unit of galena surface: At oxygen concentrations below 1 pct (the limit of accuracy of the Orsatt analyzer), no contact angle is obtained. Furthermore, no contact angle is obtained at any oxygen concentration in the absence of xanthate. This result seems to be in disagreement with those cited by Plaksin.1 Further work on the interaction of galena and potassium ethyl xanthate or a similar collector as influenced by oxygen is contemplated. The true nature of the interrelation is as yet unknown. For example, it is not known whether the governing oxygen reaction is with the mineral, with the reagent, or with both.

Jan 1, 1961

By M. J. Sinnot, J. C. Shyne

Low-frequency mechanical damping measurements were made to investigate internal friction in Fe-A1 alloys. The atomic ordering of the Fe-A1 system strongly influenced the stress-induced ordering internal friction. Magnetoelastic damping was also encounteyed and was shown to be reduced by the application of a static stress. THIS paper describes some damping experiments made on alloys of Fe and Al. Stress-induced ordering internal friction was measured with samples containing from 9.8 to 31.3 at. pct Al. Aluminum is soluble in a-Fe to about 50 at. pct and forms at least two long-range ordered structures, Fe3Al and Feu.&apos; Stress-induced ordering internal friction is known to occur in many substitutional solid solutions, but few measurements of this damping effect have been made with alloy systems that have pronounced ordering tendencies. LeClair and Lomer developed expressions relating the relaxation strength of the damping process to the degree of atomic ordering and predicted that stress-induced ordering internal friction would be zero with complete ordering.&apos; This concept was confirmed experimentally by Lulay and Wert using the system cd-Mg It is also consistent with the weak stress-induced ordering peaks observed in P -brass by Artman and in 16 wt pct Al Fe-Al by bert.&apos; It was expected, therefore that the ordering characteristics of the system Fe-Al would strongly influence the stress-induced ordering internal friction exhibited by the experimental alloys. SAMPLE PREPARATION The alloys used in this investigation were induction melted under vacuum using high-purity melting stock. The iron was electrolytically refined Plastiron 101 which contained 99.85 wt pct Fe. The aluminum was a special 99.95 pct pure grade supplied by Alcoa. The only other raw material was spectrographically pure graphite which was used in small quantities as a deoxidant. The amount of carbon used was slightly in excess of the amount required to completely deoxidize the melt; this resulted in residual carbon contents of 0.01 to 0.02 pct in the finished alloys. The vacuum cast 2 1/2-in. diam ingots were hot rolled to 5/8-in. diam round bars. Portions of these bars were hot swaged and hot drawn to 0.050-in. diam wire. Straight pieces of the hot drawn wire were slowly heated to a temperature of 1300°C in a He atmosphere. After holding for 4 hr, the samples were allowed to cool in the furnace. This annealing treatment resulted in grain growth in the samples, the final grain size being about the same as the wire diameter. The grain boundaries were oriented perpendicularly to the wire axis, giving a bamboo grain structure. The existence of a preferred orientation could not be detected in these coarse grained samples. If the samples had a fiber structure, this probably would have been the same in all samples because of similar processing, thus the influence of crystal orientation on the relaxation strength would have been similar in all samples. The aluminum contents of the alloys are listed in Table I. EQUIPMENT The principle of the torsion pendulum was used for the internal friction measuring device. The

Jan 1, 1961

By J. P. Heller, H. B. Bradley, A. S. Odeh

It is an accepted procedure to represent oil field displacement problems in which the pressure is relatively constant by a potentiometric model. Variations in reservoir permeability thickness product are represented in the model by proportional variations in electrolyte depth. It is shown that significant errors are present wherever these variations are of such magnitude that the consequent differences in the electrolyte depth in the model or any regions therein are appreciable in comparison with their respective horizontal dimensions. To demonstrate the order of magnitude of this error, a hypothetical linear oil field in which permeability varies linearly with distance was treated both analytic.ally and by potentiometric model. The results obtained from the model are compared with the exact solution for various configurations of linear geometry. Deviations in flow times up to 11 per cent were observed. It is confirmed that these discrepancies can be reduced by increasing the areal scale and/or decreasing the vertical scale of the model. It is the purpose of this work to assist in the design of potentiometric models by indicating the relationship between this error and the chosen scale factors. INTRODUCTION The fundamental geometrical criterion which determines whether the pressure distribution in an oil or gas reservoir may be simulated in a conventional potentiometric model is the requirement that all reservoir parameters be constant along any vertical line between its upper and lower boundaries. This situation never obtains exactly; nevertheless, it is usually assumed that there is no permeability stratification within the section of interest, that all wells completely penetrate the sand, that there are no gravitational effects, and that variations in thickness of the sand are small compared to the horizontal extent of the field. In these ways the reservoir problem is reduced to two dimensions in which there is no variation of pressure in the vertical direction within the limits of the sand. Variations in sand thickness and/or horizontal pesmeability may be taken into account as described by Muskat, by considering the fluid conductivity of the reservoir in its horizontal plane to be proportional to the product of permeability and sand thickness. If the variations in sand thickness are small compared to the horizontal dimensions of the reservoir, then it is a good approximation to consider the reservoir problem to be essentially two dimensional. The same approximation, however, is made in the simulation of the assumed two-dimensional reservoir by the electrolytic model. The model, if it is to take into account variations of permeability-thickness product, must of necessity be made in three dimensions, that is, with variable depth. Most potentiometric model studies and theoretical treatments reported in the literature to date2,3,4,5,6,7,8 are those in which either an average permeability was used or a constant permeability was assumed. This is understandable since detailed permeability data are not usually available for the majority of reservoirs. Many investigators have recognized that the failure to incorporate permeability variations within a reservoir in model studies leads to serious error in predictions made

Jan 1, 1957

By N. F. Schulz

The purpose of this investigation was to evaluate the effects of variables in equipment and procedure on tube test results. This information was then to be used to formulate specifications, preferably within the practical ranges of existing machines, for test procedures capable of yielding precise and meaningful data concerning the magnetic separation of any magnetite ore, regardless of its origin. A survey of current practice was conducted among laboratories using the Davis tube test. Many tube tests were performed to experimentally evaluate the variables most likely to affect test results. A simple method was then sought for adequately interpreting tube test results. The Davis magnetic tube concentrator is a laboratory machine designed to separate a small sample of pulverized magnetic iron ore into magnetic and non-magnetic fractions. It was developed in 1921 by mechanization of a test previously performed manually No significant changes have been made in the design of the apparatus since that time. The Davis magnetic tube test continues to serve as a practical basis for judging the amenability of an ore to magnetic separation and for controlling magnetic separation plant operations. The apparatus consists of an inclined cylindrical glass tube supported adjacent to closely spaced pointed poles of a powerful C-magnet. (Fig. 1). To conduct a tube test, a sample of suitably prepared ore is poured into the water-filled tube. With wash water flowing through, the tube is oscillated to gradually reject the non-magnetic and weakly magnetic ore particles until the desired degree of separation is attained. Both the magnetic concentrate and the tailings may be recovered for examination. MAGNETIC SEPARATION BY THE DAVIS TUBE Mechanical separation of a specified mineral component from an ore usually requires comminution to fine sizes for sufficient liberation. Some distinguish- ing property of the mineral is then exploited to sort the desired mineral particles from the gangue particles. The magnetic separation of iron ores is based on the fact that magnetite, Fe3O4, is strongly attracted by a magnetic field while the gangue minerals are not. Maghemite, ?-Fe2O3, which may occur in certain chemically processed ores, responds similarly to magnetite. The magnetic process is practical only when the loss of iron in the form of relatively nonmagnetic hematite, Fe2O3, goethite, Fe2O3.nH2O, or other iron mineral can be tolerated. In the Davis magnetic tube concentrator, magnetic attraction holds magnetically susceptible particles in a magnetic field. Forces due to gravity, inertia, and fluid-solid friction tend to remove the less susceptible particles from the field. The probability that a given middling particle will be rejected from the tube in a given period of time is an inverse function of its magnetite content, with some modification due to particle size and mineral specific gravities. The net result is that ore particles tend to be rejected in their order of increasing magnetite content, while the retained portion or magnetic concentrate increases in grade continuously during the process. MAGNETIC SEPARATION CHARACTERISTIC The magnetic separation characteristic or MSC of a magnetite ore is the correlation between concentrate

Jan 1, 1964

By D. C. Porterfield

ProUuction of crude oil in Venezuela increased from 186,134,000 bbl. in 1940 to 2~8,131,ooo bbl. in 1941, or 22.6 per cent, to establish a new all-time high for the country. While the average production for the year was 625,000 bbl. per day, production during the month of December 1941 averaged 751,000 bbl. per day, and during the last week of the year, 766,000 bbl. per day. Production from the Lake Maracaibo basin averaged 454,000 bbl. per day during the year, or 72 per cent of the total for the country, compared with 73 per cent of the total produced in 1940. Drilling during the year was approximately on the same scale as in 1940, with 438 wells completed in 1941 as compared with 429 the year before. Exploratory completions decreased from 18 in 1940 to 6 in 1941. Of the drilling operations in 1941, 56 per cent was concentrated in the Lake Maracaibo basin and 44 per cent in eastern Venezuela, success being 98 per cent in the Lake basin and 83 per cent in the east. Successful completions for the country as a whole amounted to 92 per cent of the total wells drilled. Exploratory drilling in 1941 resulted in the discovery of three new fields, all in eastern Venezuela; viz., Guara, about II km. to the northeast of the Oficina field but on a separate structure; Santa Rosa, which is east of El Roble field on a structure forming a part of the major Santa -Ana- San Joaquin-El Roble uplift; and Santa Barbara, which is southwest of the Jusepin field on an extension of the main Jusepin anticline. At the close of the year three wildcats were drilling, all of which showed prospects of obtaining production; that is, Mercedes No, 2 in central Guarico, Las Ollas No. I on the Anzoategui-Guarico border near the town of Zaraza, and Quiamare No. I in Anzoategui northeast of the town of San Mateo. In spite of heavy withdrawals and the resultant natural decline in the potentials of older producing areas, new drilling during the year increased the potential production of the country from an estimated 780,000 bbl. per day at the end of 1940 to an estimated 810,000 bbl. per day at the end of 1941, or approximately 4 per cent. Since domestic consumption of petroleum products is insignificant compared with total production, exports of crude and products during the year increased in line with production. Crude exports totaled 196,800,000 bbl., compared with 158,400,-000 bbl. in 1940, and exports of products were 26,100,000 bbl., compared with 21,900,000 bbl. the year before. Exports of crude from Venezuela to the United States amounted to 36,500,000 bbl. In addition, about 2,200,000 bbl. was imported in bond into the United States for transfer to Canada. Total refining capacity of the country in 1941 was approximately 125,000 bbl. per day, including a crude-conversion plant with a capacity of 32,000 bbl. per day, capable of making fuel oil only. Three plants with a capacity of 121,000 bbl. Per

Jan 1, 1945

By B. H. Caudle, R. E. Watson, I. H. Silberberg

The production history of an inverted nine-spot injection pattern was studied with a porous plate model similar to Habermann&apos;s. Colored fluids were used so the boundary movements could be photographed. By varying the production rates of the side and corner producing wells, the optimum pattern sweep efficiency can be obtained. Results of the laboratory tests indicate that interpolation of the pattern sweep and conductivity ratio data will permit application of the data to predicting fluid injection operations with mobility ratios between 0.1 and 10 and production rate ratios between I and the optimum values. INTRODUCTION The inverted nine-spot injection pattern in Fig. 1 has some unique advantages over other regular injection patterns (five spot, line drive, etc.) used in secondary recovery operations. It has three producing wells for each injection well, while the five-spot and line-drive patterns require an equal number of injectors and producers. Futher-more, of the eight producing wells surrounding each injection well, four are of the "side well" type which lie nearer the injection well than the remaining four "corner wells". This allows the production rates of these two types of wells to be adjusted independently of each other to obtain better pattern sweep efficiency. This latter advantage may well be the reason why the nine-spot patterns have not been studied as extensively as the patterns containing only one type of injection or producing well. The pattern sweep efficiency of the inverted nine spot is affected almost as much by operating with different producing rates of the comer and side wells as by differing mobility ratios. Possibly because of this added operating parameter, published studies of nine-spot systems have been limited in their coverage of the pertinent variables.&apos;-&apos; The model studies reported here covered the mobility-ratio range normally found in waterflood operations, as well as the variation in well production rates necessary to achieve optimum pattern sweep efficiency. Conductivity ratios — a measure of the change in total flow at constant pressure difference — were obtained during each model run. A porous-plate model with miscible fluids representing the in-place and injected fluids was used in this study. This model technique is the same as that used in both X-ray shadowgraph" and visual techniques4 described in the literature. Using miscible fluids eliminates residual oil in the model, and the permeability to the injected fluid is the same as to the in-place fluid. Thus the mobility ratio in the model is given by the ratio of the viscosity of the displaced fluid to the viscosity of the injected fluid. Because of the non-linear nature of the viscosity vs composition curve for two miscible liquids, the mobility change across the boundary between the two fluids is reasonably sharp. This technique thus represents the displacement of a region of one fluid mobility by a region of possibly different mobility in an isotropic system under steady-state flow conditions. Table 1 shows the dimensionless similarity groups used to scale the model conditions and results to

Jan 1, 1965

By W. C. Winegard, E. L. Holmes

The effects of the solute elements lead and bismuth on grain growth in zone -refined tin have been investigated. At low temperatures, viz. below 160°C. or at high concentrations, viz. greater than 0.03 at. pct, the temperature dependence of grain growth was found to be constant. A correlation was found to exist between the rates of grain growth in the presence of solute impurities and the factor [C Ir - 1]2 , where C is the solute concentration, r is the radius of solvent atom, and r&apos; is radius of solute atom. It is shown that the Liicke and Detert theory does not give a satisfactory explanation of the results obtained. INVESTIGATIONS of grain growth in zone-refined lead and tin and some effects of solute elements on grain growth in these metals have been reported by Bolling and winegardly2 and Holmes and winegard? The present investigation is an extension of the previous work, and was undertaken to provide additional results which might make it possible to discover the mechanism whereby the rate of grain growth is affected by the presence of foreign solute atoms. The experimental procedure was exactly the same as that described previously.3&apos;4 Figs. 1 and 2 show the results obtained with lead and bismuth additions over the same temperature range, viz. 167" to 220°C, as that used for the investigation of grain growth in zone-refined tin.3 Fig. 3 shows the results obtained for zone-refined tin and for this tin with lead solute additions over an extended temperature range. DISCUSSION OF RESULTS As mentioned previously,3 the character of grain growth in the particular zone-refined tin used in these experiments appears to change as the temperature of annealing falls below about 160°C. The grain growth became somewhat irregular and was characterized by a jaggedness of many of the grain boundaries. The reason for this change is not known, but may be due either to residual impurity effects or possibly an oxide precipitation. It was obvious that normal grain growth only occurred in the zone-refined tin through the high-temperature range 167" to 220°C, and so the effects of solute atoms on grai11 growth over the two temperature ranges will be discussed separately. a) Effect of Impurity on Grain Growth in the Temperature :Range Above 167°C. It is apparent from Figs. 1 and 2 that, for low concentrations of solute, the rates of grain growth tend towards a common value as the melting temperature of tin is approached. As the concentration of lead is increased, the rate of grain growth close to the melting temperature is also reduced, and at high concentrations the temperature dependence of the rate of grain growth appears approximately constant. It should be noteil that the effect of bismuth is greater than that of the same concentration of lead, but both these solutes have a smaller effect on the rate of grain growth than silver, as seen from an earlier investigation of Holmes and Winegard. It should

Jan 1, 1962

By D. F. Kaufman, E. D. Levine, L. R. Aronin

The deformation of&apos; impure beryllium crystals by basal glide at room temperature invariably tevminates by basal cleavage after a few percent strain. It is generally accepted that .fracture of this type is caused by the splitting of low) -angle boundaries, or bend planes, by obstacles that restrict the motion of the bed planes in the deforming crystal. The details of such a process have been developed by Stroh, who showed that the high tensile stress norrnal to the basal plane in the region where the bend plane is split results in the propagation of a basal cleavage crack, provided there is no available dejorvrlatzon mode having a shear component normal to the basal plane It has been postulated that puvification of beryllium might lead to increased basal ductility by the vemoval of barviers to bend plane motion and possibly by the activation of nonbasal defor~rlation systems. Large increases in the amount of basal glide that can he sustained prior to fracture have been observed in crystals purified by zone refining. In each case, eventudal fracture was by sharp basal cleavage, suggesting that the split bend plane model still applies to tile fracture of beryllium of rensonably high purity. In the present work, calculations are made to show to what extent basal duetilits can be increased by purification while the split bend plane .fracture process remains applicable. Experimentally observed ductilities are generally somewhat lower than those predicted by calculation because of premature failure due to defects introd~cced during specimen preparation and testing. SEVERAL investigators1-4 have studied the deformation characteristics of beryllium single crystals of commercial purity, and have related the strong anisotropy of plastic deformation in single crystals to the problem of brittleness in polycrystalline beryllium. For most orientations, the principal deformation mode is basal slip, which, at temperatures between 300" and 900°K, begins at a critical resolved shear stress of approximately 1500 g per sq mm and terminates after 3 to 6 pet glide strain by cleavage on the basal plane in the neighborhood of (1120) bend planes that are formed during the deformation. This type of fracture, which is also observed in zinc at low temperatures, has been interpreted by stroh5 to be caused by the splitting of bend planes by obstacles to their motion. In the Stroh model, a (11.20) dislocation wall, or bend plane, moving along the slip direction under the action of the applied stress, encounters obstacles which cause part of the bend plane to be held up, the other part continuing to move. Stress concentrations are built up in the region where the bend plane is split, with a high tensile component normal to the basal plane, resulting in a microcrack at the end of the split wall. Because no deformation mode having a shear component at an angle to the basal plane is available to relieve the stress at the crack tip, the crack can propagate under a sufficiently high applied stress. The Stroh criterion for crack propagation is given by

Jan 1, 1964

By J. L. Meijering

Oxidation hardening of cylindrical and spherical specimens first decreases with depth below the surface, but then increases again as the center is approached. This is in agreement with the view that this change in hardness is mainly determined by the change in velocity of the oxidation boundary, which affects the dispersion of the oxide. WHEN a thick slab of silver containing 0.3 pct Mg by weight is internally oxidized, the hardness measured on a cross section is found to decrease considerably with distance from the surface.&apos; This phenomenon has been attributed to the diminution of the velocity of the oxidation boundary. The smaller this velocity is, the more slowly the free-oxygen concentration rises towards the concentration in equilibrium with the oxygen gas. And a small 0 concentration favors dissociation and thus conglomeration of the oxide. For instance, the hardness decreases more rapidly during long annealings in nitrogen than in air.&apos; Measurements by Gregory and Smith3 on sections through internally oxidized Al-silver wire showed a smaller variation in hardness, probably because the wire diameter was only 0.9 mm. Wood4 found a drop in hardness with depth in internally oxidized Al-copper strip, and also—by electron microscopy—the concomitant increase in Al2O3 particle size. Under certain circumstances internal oxidation leads to formation of rather irregular inner oxide films in the midst of dispersed oxide. This special sort of conglomeration—discussed in Ref. 5—is also favored by greater depth below the surface.3,5 In this paper hardness measurements in large diameter cylindrical and spherical specimens are described. Here the oxidation velocity* goes through ness initially decreases with depth but increases again towards the center. Normally, the diffusion coefficient D1 of oxygen is very large compared to D2, that of the dissolved metal. If, furthermore, the atomic fraction c2 of the latter is much larger than the O-solubility cl- but c2D2 << c1D1- the velocities in question are easily calculated2 to be: for the cylinder and for the sphere. Here p is the radial coordinate of the oxidation boundary and R the specimen radius, which in dilute silver alloys is constant, as no external oxidation occurs. These equations have been derived for a divalent solute; for nondivalent solutes c2 has to be multiplied by half the valency. The equations are not valid near the center. For which can be considered as a standard case,2 the Eqs [I] and [2] begin to yield U-values which are appreciably too high for p/R = 0.05 and 0.15, respectively. But at the v-minima they are still very good approximations. These minima lie at p = emlR= 0.37R in the cylinder and p = 1/2 R in the sphere. Other factors besides the velocity v will also influence the hardness. The oxide concentration cox is constant in a flat strip, apart from a narrow region in the middle,2 but in cylindrical and spherical specimens cox decreases steadily with depth. When C1 << c2 and c1D1 >> c2D2 one can calculate

Jan 1, 1961

By Harry P. McClintock, Alec M. Crowell

Production of oil and gas condensate from the 45 oil and gas fields of South Arkansas increased for the eighth consecutive year, the production for 1943 being 27,605,647 bbl. Six new pools were discovered during 1943, bringing the state&apos;s crude oil and condensate reserve to 475 million barrels, a net increase of 70 million barrels for the year. The gross increase in proven reserve was 98 million barrels, from which, of course, is subtracted production of approximately 28 million barrels to reach the net figure of 70 million barrels. There were 35 more wildcats in 1943 than in 1942, and 29 more wells were drilled in fields of the state. Sixteen companies operated exploratory crews during the year for a total of 677 crew weeks, divided as follows: 563 weeks seismograph, 111 weeks gravity and 3 weeks core drill. There was a decided increase in gravity work and a decrease in seismic work. The year started with 15 seismic crews and ended with 5 seismograph and z gravimeter crews. Geologically, it is interesting that the number of wells bottomed in Gulf, Comanche, and Jurassic strata were near equal for the year 1943. During 1942 Jurassic was much higher than the other two. However, Jurassic still led in wildcats for the year 1943. Abandoment of wells in the stripper areas of the state reached about the same figure for the year 1943 as for the year 1942; that is, 145 wells were permanently abandoned. However, 243 wells were drilled in 1943, as against 184 for the previous year. The completions for the year were divided into 103 dry holes, 137 oil and condensate wells and 3 dry gas wells. Among new developments perhaps the most significant was the pressure-main-tenance project for the Midway field of Lafayette County, which is utilizing fresh water as the maintenance medium. This is the first fresh-water pressure-maintenance operation during primary production of an oil field in the United States. The operator of the project, Barnsdall Oil Co., estimates that the ultimate recovery of oil from this field will be increased from 32.5 to 65 million barrels. The Midway pool is of the dissolved-gas type, but a similar project is getting underway for the Magnolia field, Columbia County, a pool of the gas-cap and water-drive type. Dual completion of wells, on concurrent production from two productive zones through a single well bore, became common practice in South Arkansas during the year. As the year ended, some 50 wells had been dually completed and it was estimated that the first 37 of these wells represented a saving of more than 2 1/4 million dollars and a saving in steel of 7000 tons. The majority of the wells dually completed were those reaching depths in the neighborhood of 9000 ft. below the surface and initially productive there. Selective completion at lesser depths in the same well bore proved mechanically feasible and economically sound. The year was marked by the successful completion and placing into operation of three large natural-gas desulphurization

Jan 1, 1944

By Alec M. Crowell, J. W. Sanders

While the production of crude oil and condensate in South Arkansas increased only 1.7 per cent over the 1940 figure, complete utilization of gas produced with the oil and condensate, and heretofore wasted, was beginning to be evidenced. There were 26,229,264 bbl. of oil and condensate produced in South Arkansas during 1941, as against 25,790,380 bbl. for the year 1940. (Fig. I.) Since 1936, deep producing sands have been discovered in 18 fields and during that period only 40 per cent of the total state production has come from Upper Cretaceous formations while 60 per cent came from the Lower Cretaceous and Jurassic formations. The gas produced with crude oil and condensate from the latter formation contains large quantities of hydrogen sulphide, the maximum being 6900 grains per 100 cu. ft. in the Patton pool of Lafayette County. Gas Utilization During the latter part of 1940 and the early part of 1941, pilot plants were placed in operation to determine whether the hydrogen sulphide and deleterious material in South Arkansas gases could be removed economically. The Federal Government desired to build a large aluminum plant in the Ouachita Valley and was seeking cheap fuel for the generation of electricity. The fact that the gases were produced with appreciable quantities of crude oil and condensate made it available at a very low price, since the state&apos;s conservation law prohibits the flaring of any gas. As a result of these experiments the first large-scale unit for the processing of gases containing hydrogen sulphide was placed in operation on Sept. I, 1941. The plant is in the Magnolia oil field, Columbia County. It processes residue gas from the Shell Oil Company&apos;s gasoline plant in that field and also raw gas from the Village field, 6 miles east of the Magnolia field. The gas entering the desulphuri-zation unit is laden with approximately 1400 grains of hydrogen sulphide per 100 cu. ft. and is stripped to a content of 4 grains per 100 cu. ft. The capacity of the plant is 15 million cu. ft. of gas treated daily under a pressure of 160 lb. per sq. in. The cost of treatment, exclusive of depreciation, is appreciably less than I per 1000 cubic feet. Two other plants of much greater capacity have been announced and priorities have been granted, which should bring the total amount of gas treated to 150 million cu. ft. daily. The gas to be treated will have a maximum hydrogen sulphide content of 4500 grains per 100 cu. ft. and will be processed under a pressure of 600 lb. per sq. in. These developments are something entirely new in field practice for the industry. The fact that this heretofore wasted gas is available at very low cost has led to the location of some eight war industries within the state, in addition to the alu-minum plant. Recovery OF Sulphur The Susearch Corporation and the Southern Acid and Sulphur Co. placed in operation during 1941 pilot plants to de-

Jan 1, 1942

By H. J. Beach, W. C. Goins

The laboratory development and field use of oil well cement compositions* with high resistance to drilling mud contamination are described. Resistance is obtained by adding a I-lb mixture composed of three parts paraformaldehyde to two parts sodium chromate tetra-hydrate for each sack of cement. This mixture neutralizes the cement-retarding properties of quebracho and other tannins, starch, sodium carboxymethylcellu-lose, Ignite, and monovalent salts of lignosulfonic acid. The retarding properties of calcium lignosulfonate are unaffected. The decontaminating mixture may be used in common cement (designated Type I by ASTM specifica-tions,&apos; Class A by API Std. 10A2) or in a slow set slurry prepared from common cement by addition of calcium lignosulfonate. No changes in slurry viscosities or thickening times are caused by the protecting reagents. The method has been used in 185 field jobs where an improved success ratio has been obtained in plug setting. INTRODUCTION Field experience and laboratory investigations have established contamination by drilling mud as a major factor in oil well cement failures. During 1955, 12 attempts were required to set six open-hole cement plugs in the Timbalier Bay field, La. Eighteen to 30 hours elapsed between placing and testing the plugs in preparation for sidetracking operations. Considerations of rig time expense required immediate resetting where soft cement was drilled after a reasonable waiting period. Sea water drilling mud was used in each well and daily additions of thinners, usually lignites, had been required. Sodium carboxymethylcellulose had been added regularly to control fluid loss. The 50 per cent plug failures were attributed primarily to contamination by the mud. Similar experiences can be found in other fields along the Texas and Louisiana coasts where drilling muds normally contain large quantities of organic treating materials. Cement contamination was the subject of a survey by the Mid-Continent District Study Committee on Cementing Practices and Testing of Oil-Well Cements of the API.3 Data collected from member laboratories and released in Sept., 1951, reported the effects of a number of drilling mud treating chemicals on cement. The study revealed that many of the additives, notably the organic materials in relatively small quantities, had marked effects on the properties of cements tested. Severe losses in strength and erratic thickening time resulted from small additions of mud treating chemicals such as quebracho, starch, sodium carboxymethylcellulose, and lignite. The report included no recommendations of methods for overcoming the problem. One investigation of the contamination problem reported the successful use of activated charcoal in setting cement plugs after conventional slurries had failed.4,5 The investigation indicated that an optimum concentration of 5 per cent activated charcoal was effective in combating contamination from 16.7 volume per cent of treated mud. Laboratory and field muds were included in tests and contained varied quantities of ode or more of the following: quebracho, caustic, starch, lime, and calcium lignosulfonate. The function of the charcoal appears to be physical, removing the organic materials by adsorption. The method may be employed in API Class A or Class D (unretarded slow set) cements. The chemical approach presented here is based on

Jan 1, 1958

By N. E. Grosvenor

Several methods have been proposed for determining the tensile strength of rock. These have been tried out over the past several years, but the results have been erratic and of doubtful value. The tensile strength of rock is its weakest property, and this property apparently enters into all failure phenomena, whether underground or on the slope of an open pit. Therefore, it is essential that detailed quantitative information is known about the tensile strength of rock if the design engineer is going to select the proper pit slope, pit orientation, or orientation of underground workings so as to give the most economical and safest mining condition. This quantitative information may be used to orient the pit in such a manner as to allow steep slopes along two sides. This information possibly may be used to orient the direction of either underground workings or open pits so as to decrease powder consumption and to increase blasting efficiency. Hence it is of prime importance that a method of determining accurately the tensile strength of rocks be developed. The U. S. Bureau of Mines states&apos; that no standard methods have been proposed by the ASTM for testing the tensile strength of rock. The method described in the Bureau publication is said by them to be unsatisfactory. A similar test that has been used in our laboratory in place of the USBM test is shown in Figs. 1 and 2. h this test the core is placed in a set of grips that has been designed for one particular size core. The grips are designed to distribute the stress around the core if they are tightened correctly. A universal joint or a flexible cable may be used in conjunction with the apparatus to prevent bending or twisting of the specimen. The main difficulty encountered with the system shown is the failure of the specimen within the grips. The possible cause of the failure within the grips may be due to a stress concentration set up by the uneven tightening of the grips. This method can be used only for tests on cores, and even then has been found to be totally unsatisfactory because of the failure within the grips. The U. S. Bureau of Reclamation has been using a test similar to the sketch shown in Fig. 3. Sulfur is cast around each end of the specimen to form a bearing surface and then a ring grip is used to apply a tensile stress. The grips are in contact with the sulfur cast and do not touch the specimen. This method is unsatisfactory, apparently because a large number of the specimens appear to break within the sulfur cast. Professor Wuerker of the University of Illinois uses the test shown in Fig. 4.&apos; Professor Wuerker states2 that this method has given definite and reproducible results with the weakest as well as with the strongest rocks. The test is a supplement in all cases where cores cannot be obtained. The principle and equipment are the same as for the test for tensile strength of hydraulic-cement mortar. Soft

Jan 1, 1961

By R. C. Buehl, M. B. Royer

A three ton per day blast furnace using blast temperatures up to 2200°F was operated to recover manganese from open-hearth slag and manganiferous iron ore. The spiegel product containing 12 to 24 pct Mn was blown in a basic converter to high manganese oxide slag as described in the paper which follows this one. HE steel industry, which uses over 900,000 short tons of contained manganese yearly, depends on the maintenance of supplies of manganese from foreign sources such as India, Gold Coast, and Union of South Africa. Domestic ores furnish less than 10 pct of the yearly requirements of metallurgical ores and, unfortunately, the United States has no large, or even moderate, grade deposits that could supply a major portion of the requirements for many years. It may be necessary to obtain manganese from low grade materials, even though the cost is appreciably higher than when imported ores are used. An American Iron and Steel Institute questionnaire prepared in 1949 revealed the startling fact that open-hearth slags contained about as much manganese as is imported annually. The quantity of slag produced each year by integrated steel plants (not including cold-melt shops) and the manganese contained in the slag follows: Flush slag, 4,500,000 net tons a year containing 408,000 net tons Mn; tap slag, 7,230,000 net tons a year containing 364,000 net tons Mn; for a total of 772,000 net tons Mn. Some of this slag is returned to blast furnaces but about 75 pct would be available for the recovery of manganese. In several decades, when many of the present sources of high manganese ores have been depleted, open-hearth slag and manganiferous iron ore may become the major source of the manganese required for steel production. In 1948, manganese-ore imports from the U.S.S.R. were 427,000 net tons or 34 pct of the foreign ore. Imports from this source were only 81,000 tons in 1949. It became evident that adequate stockpiles of manganese could not be accumulated for many years. The Bureau of Mines initiated an extensive research program on methods for increasing domestic production of manganese and entered into a cooperative agreement with the American Iron and Steel Institute for recovering manganese from open-hearth slags whereby the Institute provided additional research funds and trained operating personnel. Description of Process and Equipment Numerous pyrometallurgical and hydrometallur-gical processes and combinations of the two can be applied to the recovery of manganese from open-hearth slag and manganiferous iron ore. The process being developed at the Pittsburgh Station of the Bureau of Mines consists of: 1—Reduction of open-hearth slag in a blast furnace to recover the iron and manganese as spiegel-eisen with 12 to 24 pct Mn. 2—Selective oxidation of the manganese from the blast-furnace metal in a basic-lined converter to produce a high manganese slag with up to 60 pct Mn content, which is a synthetic ore for the production of ferromanganese. This process has the advantage over other processes in that the equipment which would be used, such as blast furnaces and converters, has been highly

Jan 1, 1953

By H. T. Clark

NO previous determinations of the deformation or recrystallization textures of titanium or of titanium-base alloys have been reported in the literature. The room-temperature structure of titanium is hexagonal close-packed with a c/a ratio less than 1.633. It would be expected, therefore, to have a rolling texture similar to that of other hexagonal close-packed metals, namely (0001) [1010]. Burgers and Jacobs1 have shown that zirconium, a metal isomorphous with titanium in its structure and similar in many of its properties, has such a texture with a scatter of the basal plane toward the transverse direction. This scatter is in the opposite direction from that found in magnesium by Bakarian2 but similar to that reported by Smigelskas and Barrett3 or beryllium. The rolling and annealing textures reported here for high-purity iodide titanium are significantly different from the . textures of any other hexagonal close-packed metal. All titanium used during this investigation was prepared by the iodode process." The annealed hardness of this material varied from 73 (material used for sample No. 2) to 97 Vickers hardness number. An estimate of the chemical composition of this grade of titanium has been reported by Finlay and Snyder.5 With one exception, shown in table I, the as-deposited titanium was cast into 10 to 20 g ingots in an electric arc furnace in purified argon before being rolled to sheet. The cast ingots were forged and ground until their cross-section was approximately rectangular, annealed 1 hr at 700°C in vacuum and cold rolled. Rolling was carried out in a two-high, 4 in. diam mill, using reductions no greater than 10 pct per pass. The direction of rolling was reversed after each pass, and, in order to avoid temperature effects, the sheet was allowed to cool after each pass. Unless the rolled sheet was sufficiently thin for X-ray penetration (about 0.004 in.), it was reduced to this thickness by pickling. Because of the possibility of introducing twinning or other deformation during grinding, no attempt was made to maintain uniform thickness of the sample during pickling by intermediate grinding or sanding operations. Those samples to be used for determining the annealed texture were recrystallized by vacuum annealing the cold-rolled sheet for 1 hr at 500°C. These thin samples were held between thick titanium sheets during annealing to prevent distortion. Table I outlines the rolling and annealing schedule of those samples for which photograms or texture patterns are shown. X-ray Techniques The usual techniques for determining textures were employed during this work. Molybdenum radiation was used for the transmission exposures and copper radiation for the glancing angle ones. Since titanium fluoresces under these conditions, it is necessary to employ a filter between the sample and the film. The Kß radiation filters are very satisfactory for this purpose. Sufficient grains having favorable orientation were present in both the cold-worked and in the cold-worked—500°C annealed samples to provide satisfactory patterns with the samples stationary. Because of the difficulties of comparing intensities of transmission photograms with those obtained

Jan 1, 1951