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By S. S. Nosseir

INTRODUCTION General Quebec Cartier Mining Co. (QCM) , Canadian subsidiary of U . S. Steel Corporation, operates two iron ore concentrators at the North Shore of Quebec, Canada. In its own operation at Mount-Wright, over 45 million tons per year of crude ore are ground, fully autogenous in six 32' x 11-1/2 Dominion Engineering mills. At Fire Lake/Lac Jeannine operation, property of Sidbec Normines Incorporated (SNI), over 11 million tons per year of crude ore are now ground, fully autogenous, in twelve 18' x 5' Hardinge mills. The Lac Jeannine concentrator was originally constructed by Q.C.M. in 1960 and. was since operated, in beneficiating the Lac Jeannine ore deposit until fully depleted in 1977, at an annual capacity of 18 million tons of crude per year. In 1976, the new company, Sidbec Normines, was incorporated by Sidbec Corporation, British Steel Corporation and Quebec Cartier Mining Co., in proportional holding of approximately 51 to 41 to 8 percent respectively. Since the acquisition of the Fire Lake ore deposit and Jeannine concentrator by the new company, QCM has continued managing the mine and concentrator operaions for S idbec Normines Inc . Flow-Sheet Design Jeannine concentrator comprises twelve identical mill lines grinding the ROM from 8" top size to 14 mesh nominal size range. Driven by 600 H.P. motor at 13.4 RPM corresponding to 73% critical speed, each mill is operated in a closed circuit with two 5' x 12' vibrating screens dressed with 2.5 x 25 mm slot opening cloth. The ground product or screen undersize at an average grade of 33.4% Fe is beneficiated by gravity separation to produce 66.5% Fe concentrate grade at 42.7% weight recovery. At the rougher stage, each mill line con-tains 128 Humphrey 13- 1/2" pitch spirals which produce a final tailing, middling and concentrate products. The rougher concentrate - so produced - is classified by 64 Humphrey pocket sizers into an underflow, which is a final concentrate product and an overflow which is further upgraded by 64 cleaner spirals. The cleaner concentrate together with the pocket sizer 's underflow are dewatered on a 13'[6] horizontal filter. The rougher middling together with the cleaner tailing are recycled in a closed circuit with the spirals. The rougher tailing after dewatering by hydrocyclones is disposed of by a

Jan 1, 1982

By W. M. McKewan, R. G. Olsson

In order to improve the understanding of the iron oxide reduction mechanism, the rate of equal molar diffusion of hydrogen and water vapor was measured through disks of porous iron and alumina. The measuretneizts were made at atmospheric pressure at 800°, 900- , and 1000°C. It is shown tint the reduction of dense hematite pellets with hydrogen at these temperatures and at atmospheric pressure is to a great extent limited by gaseous diffusion between the bulk-gas phase and the iron-wustile interface. THE investigation of the reduction of iron oxides with hydrogen has been the subject of numerous papers. Although the effects of temperature, pressure, and gas composition on the rate of iron oxide reduction have been studied, the actual mechanism of the reduction process has not been definitely determined. As a means of improving the understanding of the mechanism, the rate of equal molar counterdiffusion of hydrogen and water vapor was measured through porous iron and porous alumina disks at reduction temperatures. The alumina was used as a basis of compari-son because its pore structure is homogeneous and independent of temperature. The porous iron was prepared by the reduction of dense hematite disks with hydrogen at the temperature of the subsequent diffusion experiment. The hematite disks were made from pellets that were identical to those used by McKewan1,2 in his study of iron oxide reduction with hydrogen. In these investigations the weight loss and rate of movement of the various interfaces were measured as a function of the reduction temperature and gas composition. With these reduction data and the presently reported diffusion data it is possible to determine the importance of H2-H2O transport between the bulk-gas phase and the Fe/FeO interface to the reduction of dense hematite. APPARATUS AND PROCEDURE A porous iron or alumina sample was held in the base plate of a sealed canister containing porous granular wustite, as illustrated schematically in Fig. 1. The canister was suspended from an automatic recording balance in a vertical tube furnace through which flowed hydrogen and water-vapor mixtures of known composition at atmospheric pressure (0.96 atm). Hydrogen from the gas stream diffused through the porous sample, reducing the wustite in the interior of the canister. The water vapor that was formed diffused back to the gas stream. The rate of diffusion was determined from the recorded weightloss data. The furnace, automatic balance, and gas-metering equipment have been described previously.2 The main body of the canister and the tubing extension were made of stainless steel while the base plate was made of high-purity iron. The main body of the canister was % in. in diam. It held approximately 6 g of porous granular wustite that was prepared by reducing 0.1- to 0.2-cm-diam specular hematite particles at 900°C with an H2-H2O mixture of a composition near the iron-wustite equilibrium value. The upper end of the 1/8-in.-diam tubing extension was sealed with a segment of plastic tubing and a tubing clamp. The temperature at the top of the furnace was sufficiently high so that no water vapor condensed inside the extension. In the experiments with porous iron, iron oxide samples were prepared from reagent-grade hematite that was pressed and sintered in a manner previously described.' The resulting pellets had a density of 5.15 ± 0.05 g per cu cm. Each pellet was centerless-ground

Jan 1, 1967

By L. E. Mannion

Sodium carbonate or soda ash is one of the two principal alkalis of commerce, the other being sodium hydroxide. The use of sodium carbonate is recorded in ancient Egypt, where naturally occurring brines or solid salts were the source of impure soda for glass manufacture. In early modern times until the 19th century, soda ash, as well as potash, was recovered mainly by leaching the ashes of plants. In Europe, during the 18th century, a brown lye for laundering was produced by pouring hot water over burned seaweed. One of the better grades of this kind of material was a product from Spain termed "barilla," which analyzed 24 to 30% Na2CO3 (Hou, 1942). The birth of the modern chemical industry may be said to start with the LeBlanc process for making sodium carbonate from salt, sulfuric acid, and lime. Although invented in France in 1691, England made the most extensive use of it. In 1863 Ernst Solvay devised the ammonia-soda or Solvay process, and by 1874 the first of many Solvay plants was built. These were to supplant the LeBlanc method and dominate soda-ash production until the present time. Although of lesser importance, natural sodium carbonate deposits continued to support operations in various parts of the world. Shortages during World War II stimulated production of "natural" soda ash, particularly at Searles Lake, Calif., and at Lake Magadi, Kenya. Within the last ten years in the United States, a notable surge in production has occurred based on the vast trona deposits in Wyoming. Table 1 lists some principal producers of natural soda ash and the character of the source deposits. Uses and Specifications Sodium carbonate (Na2CO3) is a white, crystalline hygroscopic powder, an aqueous solution of which is strongly alkaline. Most commercial soda ash is a product that must meet high standards of purity and uniformity. Two forms are commonly sold: a fine, powdery material called light ash, and a more coarsely crystalline dense ash; these weigh 32 to 39 and 60 to 66 lb per cu ft, respectively. Dense ash may be produced by adding a little calcium chloride to the sodium carbonate solution to control crystal size and prevent agglomeration. Specifications and typical analyses of light and dense ash in the United States are shown in [Table 2]. Sizing generally achieves about 75% of light ash and 90% of dense ash between +30 and -100 U.S. screen mesh. World use of sodium carbonate now exceeds 24 million tpy, of which the United States produces more than 7 million tons. The market for soda ash is dominated by the glass industry, which uses almost half the supply. Inorganic chemicals, including phosphates and silicates, consume about 30%. Other principal uses include the manufacture of soaps and detergents, petroleum, caustic soda, organic chemicals, and paper; and nonferrous and ferrous metallurgy. [Fig. 1] shows the percent consumption by use of soda ash in Europe, Japan, and the United States. The price of soda ash in the United States remained relatively stable during the 1960s at about $33 per ton; in 1972 it reached $35 per ton. The price in 1975 was $42 per ton. Geology Mineralogy [Table 3] is a list of the more common sodium carbonate-bearing minerals. Anhydrous sodium carbonate is almost never found in nature; only natron, thermonatrite, and trona have been used directly as sources of sodium carbonate. At Searles Lake, burkeite and hanksite are important in the reconstitution of

Jan 1, 1975

By J. C. Savins

The practical analysis of the hydrodynamics of the wellbore has long been a subject of interest to engineers. This paper presents a simplified solution to the problem of computing the pressure drop for the flow of drilling mud in the annulus of the wellbore. This solution is, however, an exact and rigorous solution under the assumptions which have been imposed. These assumptions are that the drilling fluid is a Bingham plastic fluid* and that the annulus is formed by two concentric, stationary, cylindrical pipes. It is further assumed that the fluid is incompressible and that its motion is isothermal and in a steady state. This problem under the same assumptions has been attacked by previous authors. Beck, Nuss and Dunn' proposed that the equation for the flow of a Bingham plastic fluid in a cylindrical pipe could be applied to an annulus if the pipe radius were replaced in the equation by the hydraulic radius. This equation, known as the Buckingham-Reiner equation' (see Appendix 1), was also used in an approximate form. Van Olphen pointed out that even for a simple or Newtonian- fluid the pipe equation (Poiseuille's law) could not be converted to the Lamb equation escriptive of flow in an annulus (see Appendix 1) by using the hydraulic radius. Van Olphen further attempted to give a solution for the annular flow of a Bingham plastic fluid by introducing approximations similar to those which have been used in the case of the Buckingham-Reiner equation. Other attempts to provide approximate or exact solutions have been made by Grodde' and by Mori and Ototakeq. The present authors some years ago in unpublished work derived the correct expressions relating the pressure drop and flow rate for this problem. It was found that the solution consisted of two simultaneous equations, one of which contained a logarithmic term. Thus, obtaining numerical results for any particular case of interest involves very tedious trial-and-error computations. Very recently Laird presented the correct derivation of the two equations which are given in full detail in Appendix 1. In order to reduce the amount of calculation time which would be involved in providing a complete tabular or graphical solution to the problem, a high-speed electronic digital computer has been utilized. For this purpose the two simultaneous equations were transformed into more compact expressions by introducing reduced variables. These expressions are given in the following theoretical section. A similar procedure in this problem has been developed by Fredrickson and Bird1" Their tabular results, however, are very incomplete in the range of practical interest for problems of wellbore hydrodynamics. We have furthermore been able to express our graphical results in terms of convenient and familiar dimensionless groups. THEORETICAL DEVELOPMENT Use of Reduced Variables In terms of reduced variables the two simultaneous equations just discussed take the following form, The reduced variables q, x, a and z are defined in terms of the various measured quantities, where Q is volumetric flow rate, AP/L is pressure gradient, Dl is OD of inner pipe, D, is ID of outer pipe, is plastic viscosity, and is yield point. Thus, we have a dimensionless volume flux, a dimensionless reciprocal pressure gradient, and the ratio of the pipe diameters Before introducing the fourth reduced variable, z, it is of interest to consider the physical significance of the parameter x. As may 'be seen from the velocity profile of Fig. 1 the Bingham plastic fluid has the interesting property that a portion of the stream flows at a uniform velocity without shearing action. This section of the stream is situated approximately in the center of the conduit and is known as the "plug flow" region. Its existence is due to the fact that the shearing stresses within the region do not exceed the yield point, which is one of the two flow properties characterizing the fluid. The parameter x then turns out to be the ratio of the

By A. D. Brokaw

The so-called "paraffin dirt" of the Gulf Coast oil fields has been considered an indication of the possible presence of oil and gas, and not a few wells have been brought in solely on the basis of such evidence. In a sense, it may be empirically justified as evidence of the presence of oil or gas, though it cannot be said to be infallible. If the writer is correctly informed, its association with oil and gas was pointed out by Lee Hager some years ago, and while it is commonly mentioned by geologists and operators in conversation, no discussion seems to have found its way into print. The present interpretation is based on laboratory study rather than on field investigation, and is put forth with the hope of stimulating discussion which shall lead to more complete understanding. The term "paraffin dirt" has been applied to soils with a peculiar texture, which has been described as "curdy" or "rubbery." When moist, the material breaks much after the fashion of "green" cheese. It is rubbery under compression, but does not resemble rubber in tenacity or cohesion. When dry, the material ranges from hard clods to a horny mass of high tensile strength. The shrinkage in drying is very great, especially in the hornlike matter. The moist material ranges in color from dark brown in the specimens rich in organic matter to grayish in specimens containing more inorganic matter. All of the specimens studied were readily attacked by molds, which in some cases grew in great profusion on the samples. Samples exhibited a rather characteristic "swampy" or "mucky" odor when wet, and a characteristic odor of humic soils when moist. If the material is brought into suspension in water, very fine sand settles out and may be recovered by successive washing and decantation. The sand is almost entirely quartz, but contains occasional fragments of feldspar—more or less kaolinized and iron-stained. Practically all of the sand passes through a 100-mesh screen and the grains are extremely sharp —possibly below the limit of rounding. A flocculent mud, of clay and organic matter, remains in suspension for days. Some material is taken into solution in the water, imparting a slight tendency to froth when vigorously shaken. The results of partial analyses of four samples of "paraffin dirt," and, for comparison, one of a coastal plain soil are given in Table I.

Jan 1, 1920

By F. C. Miller

The metallurgical fuel of Colorado, Utah, and New Mexico has been a Veiny tardy member in the caravan of western industrial progress. The history of western coke has naturally been closely related to the development of the metallurgy of iron and steel and the precious metals, in the State of Colorado. It was at Leadville, with a population of 300 in 1877, that the Sentinel was published by Richard S. Allen. The Sentinel gave very full accounts of the various mineral discoveries at the new town of Leadville, which found their way to the more widely circulated journals of the East, and attracted the attention of many people. At the close of 1878, a census slowed a total of 5040 persons. The first smelter was established in 1877, at Malta, two miles from Leadville, by A. R. Meyer, but was not successful. It was succeeded by the Harrison Reduction Works, in 1878. The La Plata began with one furnace in June, 1878, and in 1879 had four furnaces in active operation. These furnaces used charcoal for fuel, and, because of hot tops, suffered a tremendous loss in lead and silver. This difficulty was overcome by the erection of 50 single-bank 10-ft. beehive ovens at Crested Butte, Colo., in 1880. The slack coal sent to these ovens was very pure, and yielded a coke carrying as little as 4.5 per cent. ash. Among the pioneers in the Leadville district were Grant, Eddy, James, Billings, Eiler, and Dickson. To these men the West owes the present expansion of its mining industry, and the erection of metallurgical processes for the treatment of precious metals. On Mar. 1, 1876, Pueblo was connected to the Atchison, Topeka & Sank Fe by the Pueblo & Arkansas Valley branch. The first smelter was erected in Pueblo by Mather and Geist. This modest plant grew into the immense Pueblo Smelting and Refining Co., now a part of the American Smelting and Refining Co. Coke for these small furnaces was made from unwashed Engleville coal, in 186 single-bank 12-ft. ovens at El Moro, in the Trinidad district, and it was not uncommon for the percentage of ash to exceed the percentage of fixed carbon in the coke. On Jan. 23, 1880, the Colorado Improvement Co. consolidated

Jan 1, 1920

By J. Marvin Weller, M. King Hubbert

Preliminary investigations were undertaken with a Megger Ground Tester in 1931 by Hubbert to determine whether the faults in Hardin County, Illinois, could be located by earth-resistivity surveys. The results of these investigations, which were in part presented before this Institute in 1932,1 were sufficiently promising to warrant a more extensive field program in the same general area the following summer. During the second season an apparatus of the Gish-Rooney type was employed because of its greater sensitivity and to avoid the troublesome correction for resistance of potential electrodes necessitated by the use of a Megger instrument. The discussion of earth-resistivity traverses which constitute the main part of this paper is based entirely upon the results of the second season's work. All of the traverses were made with a constant electrode spacing of a equal to 100 ft., and the four-electrode technique was employed. Successive stations in these traverses were spaced at intervals of 100 ft. and the line of electrodes was carried parallel to the line of traverse. The graphs of resistivity profiles presented here (Figs. 1 to 3) are plotted with resistivities in ohm-centimeters as ordinates and with distance divided into stations at 100-ft. intervals as abscissas. After the traverses were run by Hubbert the results were computed, the profiles plotted, and tentative interpretations were made by him. These curves and interpretations were then taken into the field by Wellcr, who made a careful geological examination along the lines of traverse for the purpose of checking and supplementing Hubbert's interpretations. Weller then constructed a geologic cross-section extending along the line of each traverse. The accompanying diagrams graphically illustrate the correlation that can be made between earth resistivity and geology in this area.

Jan 1, 1934

By W. D. Robertson, R. E. Reed-Hill

DEFORMATION of magnesium crystals in a direction parallel to the basal plane has a special significance as a result of the preferred orientation characteristic of cold worked and recrystallized polycrystalline magnesium sheet and extruded rod in which the basal plane tends to lie in or near the plane of the sheet or the axis of a rod. The principal objective of the present study is a determination of the modes of plastic deformation in magnesium single crystals in this orientation. Evidence for nonbasal slip in magnesium has been presented by a number of authors. Schmid and Was-serman&apos; indicated that pyramidal slip on {1011} < 1120> or {1012} <1120> could occur above 225°C. Bakarian and Mathewson2 stablished that the slip system {1011} <1120> operates at high temperatures and that 225°C was a lower limit for pyramidal slip. The latter authors also showed that the critical resolved shear stress for {1011} slip was 400 g per sq mm at 330°C, while that for basal slip was 66 g per sq mm at the same temperature. Thus, at 330°C basal slip should be expected for all orientations except those in which the stress axis lies almost in the basal plane. More recently Burke and Hibbard3 oserved pyramidal slip at 25°C, when the stress axis was 6" to the basal plane and 14" to a <1120> slip direction. The critical resolved shear stress for pyramidal slip was 52 g per sq mm, which is only slightly greater than their value for basal slip (46 g per sq mm). Chadhuri, Chang, and Grant4 have observed non-basal slip in creep tests with polycrystalline specimens in the temperature range 250" to 350°C. The observed slip bands, which were extremely irregular in appearance, can be explained in terms of cooperative slip on {1011} and (1010) planes which have a common slip direction. Prismatic (1070) slip in polycrystalline magnesium was observed by Hauser, Landon, and Dorn.5 It was found to occur at low temperatures (78" and 195°K) and it was accompanied by cross slip in which the cooperating plane was the basal plane. Since prismatic slip occurred only at regions of high stress concentrations, the critical resolved shear stress could not be determined. Experimental Procedure The present work was performed on crystal specimens which were all cut from the same large single crystal. The original cylindrical crystal, 0.5 x 7 in., was grown in a Bridgman type furnace in which the temperature gradient was moved past the stationary crystal in the manner described by Jillson6 and Burke.&apos; High purity magnesium was furnished by the Dow Chemical Co. with the following spectro-graphic analysis in weight percent: 0.003 pct Al, <0.01 pct Ca, 0,002 pct Cu, <0.001 pct Fe, 0.008 pct Mn, <0.001 pct Ni, <0.002 pct Pb, <0.01 pct Si, <0.001 pct Sn, and <0.01 pct Zn. The large crystal was cut into four cylindrical pieces about 1.5 in. long. A flat surface parallel to the basal plane was made by hand grinding with lubricated metallographic paper on one side of each cylinder. In order to prevent bending in subsequent cutting operations, the crystals were supported by

Jan 1, 1958

By Dorsey Hager

THE rapid increase of water troubles in the Mid-Continent oil fields is causing much alarm. Troubles occur at Towanda, Eldorado, Augusta, Cushing, Blackwell, and Healdton, although they had, not been acute in the Mid-Continent field until about two years ago, when the unusual conditions in the deeper oil fields were first encountered. California faced the same situation, but, thanks to aggressive measures, has largely overcome the dangers. The following analysis of water trouble may throw some light on the subject and be of assistance in solving the problems involved. WATER TROUBLES CLASSIFIED The presence of water in large quantities in oil sands has the following results: 1. Diminishes oil production. 2. Diminishes casing-head gasoline production: (a) By curtailing the gas flow. (b) By making the use of vacuum pumps unsuccessful. 3. Increases lifting costs: (a) By making it necessary to pump large quantities of water, which requires. a fast motion and long stroke (third hole). (b) By requiring the use of compressors for air lift. (c) By causing break-downs and delays due to the high speed necessary to pump water. (d) By making it necessary to treat "cut" or emulsified oil. Oil production is seriously curtailed by the presence of large quantities of water. Lease records show that wells are shut down 40 to 60 per cent. of the pumping time where serious water trouble occurs. While a small quantity of salt water may cut the paraffine and keep the oil moving, several hundred feet, or a hole full of water, effectually "kills" the oil

Jan 10, 1918

By D. G. Westlake

Resistance was measured as a function of temperature, 77° to 350°K,for niobium with hydrogen concentrations up to 3.76 at. pct. Cooling curves exhibited a discontinuity in slope that was attributed to the initiation of hydride formation. A thermal hysteresis was explained in terms of diffusion and the effects of mechanical constraint on nucleation and growth. The heat of solution of hydrogen in saturated Nb-H solid solution was 2. 737 * 0.045 kcal per g-atom, including an unknown stress contribution. The critical ternperatures for hydride formation during cooling and for embrittlement are correlated but not coincident. This, too, has been explained in terms of mechanical constraint and stress-itlduced tratzsfomtation. Nb-H alloys undergo a ductile-brittle transition with decreasing temperature.&apos;-3 Similar behavior has been noted for v-H.1,5 For the latter system, there is evi-dence6 suggesting coincidence of the temperature of minimum ductility and the critical temperature T, for initiation of metal hydride precipitation during cooling. A decrease in ductility due to the presence of brittle hydride particles is readily explainable. The fact that ductility begins to decrease at some temperature higher than T,4,5 has led us6 to suggest that precipitation may be strain-induced locally during tensile testing. Wood and Daniels&apos; have reported that a plot of temperatures for 10 pct reduction in ductility vs hydrogen concentration in niobium is not coincident with, but parallels, the solvus.7,8 They believe this indicates a correlation of precipitation and embrittlement. Unfortunately, the two reported solvuses 7,8 to which Wood and Daniels refer are not in agreement with each other. Furthermore, neither solvus was determined experimentally: each was a plot of calculated solubilities. Thus. neither is highly dependable for determining whether embrittlement coincides with initiation of hydride precipitation. Longson 9 studied phase relations in the Nb-H system between 77° and 473°K by dilatometry. Comparison with metallographic observations convinced him that discontinuities in the slopes of his dilatometric plots were coincident with the initiation of hydride precipitation. Plotting the logarithm of the hydrogen concentration vs the reciprocal of the temperature at which precipitation was initiated during cooling, he obtained a straight line shown in Fig. 1. Walter and chandler,&apos;&apos; using X-ray techniques to detect the for mation of a second phase? have obtained three experimental points in the temperature range 295° to 338°K which fall within Longson&apos;s experimental error for this plot. A similar plotg of temperatures at which dissolution was completed during heating was a parallel line shifted toward higher temperatures. A straight-line plot was obtained, also, for the temperatures of the ductile-brittle transitions,9 but it was shifted toward still higher temperatures. Longson calculated an activation energy of 2.980 * 0.300 kcal per mole for the hydrogen embrittlement mechanism, compared with 3.180 * 0.400 kcal per mole for hydride formation. Despite this agreement, he concluded, "It seems unlikely that embrittlement results from hydride formation..." because hydrogen embrittlement was observed at temperatures above the solvus. It is our contention that embrittlement is correlated with precipitation of the hydride.6 Because only Longson has investigated Nb-H phase relations at sub-ambient temperatures, we deemed it advisable to re-determine the temperature dependence of the solubility using the resistometric technique already proven successful for the V-H system.6 Coincidence of our solvus with temperatures for embrittlement would

Jan 1, 1970

By E. P. Sadowski, L. P. Trudeau, C. R. Cupp

The apparent high radiation resistance of two varieties of maraging steel is described and an indication is given of some phenomena that require further study. Two aspects were included in this work: a) effects of neutron irradiation on the room-ternperature tensile properties of 18 Ni (250) maraging steel; b) effects of neutron irradiation on the room-temperature tensile properties and on the impact resistance of 12 pct Ni-5pct Cr-3 pct Mo maraging steel. Subsize tensile and impact test specimens were used. The 18 pct Ni steel was irradiated to a neutron fluence of 3.3 x 10 n per sq cm (>1 mev). The 12-5-3 variety was irradiated to two neutron fluence levels: 1) 1.5 x 10 per sq CTTL (>I mev) 2) 3.1 x 10&apos;9nper sq cm (>1 mev) In all respects both varieties showed unusually high resistance to change in strength and ductility after neutron irradiation. There was no noteuorthy over-aging in fully aged specimens. The aged 18 pct Ni variety showed a 4 pct drop in yield strength upon irradiation with little or no decrease in ductility. The aged 12-5-3 variety showed a 5 pct increase in yield strength on irradiation with a very slight decrease in ductility. The impact transition of the 12-5-3 variety only increased 35 to 45 Co upon irradiation, and the shear energy fracture value for the subsized specimens decreased only half as much as expected frorn experience with conventional steels. THE development of new reactor concepts and nuclear technology now depends to a large extent on the availability of new alloys capable of operating in stringent reactor environments. One of the most important new types of metallurgical material that has been developed in recent years is the maraging steels. This type of alloy is notable for its remarkable retention of toughness at high strength levels. In the course of a research program which incorporated ambient temperature radiation effects studies to determine the mechanisms of strengthening of 18 pct nickel maraging steel,&apos; it became evident that the resistance of the alloy to neutron-induced changes in mechanical properties should be studied. This paper is to present evidence for the apparent high radiation resistance of maraging steel. The experimental program was in two parts: a) Effect of neutron irradiation on the room-temperature tensile properties of 18 Ni (250) maraging steel. b) Effect of neutron irradiation on the room-temperature tensile properties and on the impact resistance of 12 pct Ni-5 pct Cr-3 pct Mo maraging steel, a cobalt-free alloy. EXPERIMENTAL PROCEDURE 18 Ni (250) Maraging Steel. Tensile test specimens were machined to the dimensions shown in Fig. 1 from $-in.-diam hot-rolled bar of the composition shown in Table I. All specimens were austenitized for 1 hr at 1500°F (815°C) in argon and water-quenched. Half of the specimens were then mar aged for 3 hr at 900° F (482°C) in argon. The specimens were irradiated in a fast neutron transformer rod at approximately 120°F (50°C) to a neutron fluence of 3.3 x 10 10 n per sq cm (>1 mev). The irradiation was performed in the NRX reactor of Atomic Energy of Canada, Ltd., at Chalk River, Ontario, Canada. In all cases, the thermal neutron flux was three times as high as the reported (> 1 mev) fluxes. The room-temperature tensile tests were performed with an Instron tensile testing machine operating at a crosshead speed of 0.05 in. per min. The loading frame of the machine, mounted in a hot cell, was remotely controlled. The specimens were tested either

Jan 1, 1968

By C. Zener

HE present paper has its origin in an attempt A by the author, extending over the last several years, to understand the influence of the magnetic properties of the constituent atoms upon the various properties of metals and alloys. During this study the author has been impressed by the important role which magnetism plays in the many facets of metallurgy. In writing this paper he has attempted to convey to his colleagues some concept as to the role magnetism will play in the future development of metallurgy. In some of the subjects herein discussed, such as the influence of magnetism upon phase boundaries and upon mechanical properties, only general thermodynamical properties associated with ferromagnetism are introduced. For these subjects, it is not anticipated that any serious differences of opinion will be encountered. A discussion of the other subjects requires the adoption of a quite specific model of the magnetic structure of the metal. This model is discussed under "Magnetic Shells and Their Interactions." The simple model adopted in this paper has been criticized&apos; as being mathematically inconsistent. This criticism has been ably silenced by Dr. W. J. Carr&apos; of this laboratory. The simple model adopted in this paper has been criticized as being inconsistent with observations on magnetic structure using neutron diffraction. This apparent discrepancy has been resolved by Bader3 who has shown that the finite velocity of neutrons prevents neutron beams from detecting the anti-ferromagnetic structure of the type predicted by the simple model adopted in this paper. Magnetic Shells and Their Interactions An electronic shell of an atom is specified by two symbols.&apos; The first symbol is a number and denotes the total quantum number of the shell. The second symbol is a letter and denotes the orbital angular momentum of each electron within the shell. The letters s, p, d, f are used to denote an orbital angular momentum of 0, 1, 2, 3, respectively, in units of h/2a, where h is Planck&apos;s constant. As we pass from scandium to nickel in the first transition period, we eraduallv fill the 3d shell. This shell is responsible for ferromagnetism and hence may be called the magnetic shell. The component of the orbital angular momentum along some specified direction must be an integral multiple of h/2~. Thus, for a d electron this component can have any one of the values —2, —1, 0, 1, 2 times h/2a. In addition to its orbital angular momentum, each electron has an intrinsic angular momentum, hereafter called spin, due to a rotation about its own axis. This spin can have either of two components + Yz (h/2a) or — Yz (h/2~) along the specified direction. A fundamental principle of atomic structure, known as Pauli&apos;s exclusion principle, is that no two electrons in a given shell may have identical components of orbital angular momentum simultaneous with identical components of spin. The 3d shell thus may have at most ten electrons. Since an intrinsic angular momentum of a charged particle is necessarily associated with a magnetic moment, the spin of an electron may be thought of as referring to either this angular momentum or to the associated magnetic moment. The electron configuration of the ground state of the isolated atoms in the first transition row is reproduced in Table I. The superscript represents the number of electrons in each shell. For the purpose of this paper, the most important principle of atomic structure relates to the manner in which electrons are added to a shell as the atomic number is increased. This principle, commonly known as the principle of highest multiplicity or more simply as Hund&apos;s rule, states that within a given shell the maximum number of electrons have spins pointing in the same direction as is consistent with Pauli&apos;s exclusion principle. An application of this principle to the d shell is illustrated in Fig. 1, where the spin structure is given for shells containing from 1 to 10 electrons. The physical basis of Hund&apos;s rule is the exchange energy discussed first by Heisenberg in 1928. This is a coupling between electrons with parallel spins (spins pointing in the same direction), the coupling

Jan 1, 1956

By A. V. Pegler, R. C. E. Bray

The purpose of this study is to determine the distribution of stresses in a particular portion of the ore body of an operating mine. DESCRIPTION OF GEOLOGY The ore body of this base metal mine is a lenticular mass of copper-zinc-iron sulfides, enclosed in a drag-folded quartz mica schist. The schistose host rock has steep dip which varies from north to south and an east-west strike. The drag-fold plunges eastward at about 35º, and this gives a rake of similar inclination to the bottom horizon of the ore zone. The core of massive sulfides is surrounded by an irregular envelope of disseminated sulfides in the schist, so that stope walls are comprised, in most cases, of strongly foliated schist. Adjoining the schist on the south is competent gneiss, while instrusive into the schist in a direction nearly parallel to the foliation is a series of discontinuous quartz diorite dikes, whose contacts with the schist often prove to be lines of weakness. Coarse to fine-grained pegmatites of irregular dimensions are a second type of intrusive associated with the ore body. These dikes generally strike north-east and dip westerly at about 65º. They therefore intersect the schist at an obtuse angle. The dikes are considered to be older than the massive

Jan 1, 1972

By D. G. Westlake, U. F. Kocks

WHILE single crystals of most materials with cph lattice structure show essentially unlimited ductility, polycrystalline specimens of the same materials exhibit the entire range of ductilities. A difference between the ductility of single crystals and polycrystals may be associated with the special stress concentrations to be expected, for example, at the intersections of slip bands or twin lamellae with grain boundaries. Whether such stress concentrations prove catastrophic depends on the cleavage strength of the material, the size of the stress concentrations, and the speed with which they are formed. Thus, the ductility may vary in degree from material to material. Another possible reason for differences in ductility between single crystals and polycrystals is that a sufficient number of independent deformation modes must be available to insure compatibility between the macroscopic strains in neighboring grains.&apos;&apos;2 This criterion is often taken to be a necessary condition for any polycrystal ductility whatsoever, not as one that determines different degrees of ductility; thus, a material with an insufficient number of independent deformation modes would have to be brittle as a polycrystal. The "sufficient number" is five if every grain is to accommodate arbitrary shape changes ("von Mises criterion "). We should like to argue that fewer than five independent modes may be sufficient to satisfy compatibility conditions; and that the internal stresses set up when the plastic strains are not compatible reach the theoretical fracture stress only after a significant amount of macroscopic strain has taken place which may vary in magnitude from case to case, allowing an influence on the degree of ductility. Experimental evidence for these statements is taken from the following review of the number of independent deformation modes observed in the various cph

Jan 1, 1968

By K. G. Davis, P. Fryzuk

WEINBERG,&apos; in an investigation of solute distributions along unidirectionally solidified rods of dilute silver in tin alloys, concluded that, for rods of 2 mm diameter or larger, a very high degree of convective mixing takes place in the melt ahead of the advancing interface. Suggested causes for this mixing were (1) thermal convection, (2) convective currents set up by changes in fluid density associated with concentration gradients, and (3) currents set up by changes in volume during freezing. Evidence was presented that causes (2) and (3) were not primarily responsible for solute mixing. Further, convective mixing took place in horizontal rods with temperature gradients as low as 6°C per cm, putting doubt on the importance of thermal convection. In the present work, convective mixing is examined in melts with known initial solute distributions. The absence of a moving solid-liquid interface eliminates convection caused by volume changes on solidification. In the first experiment, three silica tubes 2 mm in diameter and approximately 20 cm long were filled with an alloy of 100 ppm Ag in tin (99.999 pct purity), placed adjacent to one another in a horizontal furnace, and solidified from one end at 1 cm per hr. A110, a Y emitter, was used as tracer. A few centimeters at the start of the rod were left un-melted, to determine the initial concentration Go. After solidification was complete, one sample was removed. The hot furnace was then brought back to

Jan 1, 1965

By Sterry Hunt

The American Institute of Mining Engineers, and American science in general, have sustained a great loss in the death of Prof Benjamin Silliman, deceased at New Haven, Connecticut, on the 14th of January, 1885, at the age of sixty-eight. But a month has passed since, as one of the pall-bearers, I paid the last tribute to the remains of my old friend and honored master.

Jan 1, 1885

By L. G. Schulz

THE possibility of using reflected X-rays to produce images of crystals was explored by Barrettl who developed simple experimental procedures for X-ray microscopy and who showed by numerous examples the great range of information that could be made available. In his method characteris radiation is used to produce an image of a limited area of the sample on fine-grained film, this image subsequently being enlarged approximately X100. A somewhat different method will be described here;&apos; white radiation from a fine-focus X-ray tube-"&apos; is used to produce an image of a relatively large area of a single-crystal surface. part of the sample; therefore, white radiation is needed. The resolution in the image formed on the photographic film will depend on the size of the focal spot of the X-ray tube. If the sample is made

Jan 1, 1955

By C. W. Reith

The development of production in West Texas during the year 1933 was largely confined to the expansion of proven areas, especially Ward County, Iatan and North Winkler. Wildcat activity was at a comparatively low ebb and resulted only in discoveries of probable minor importance in Ector County. The interest shown in deep wildcatting to test beds of pre-Permian age was a new development, which should soon throw light on the possibilities of deeper production from the present producing fields. The important pre-Permian tests of the year were: 1. Stanolind Oil and Gas Co., Todd No. 1, a unitized test, in north central Crockett County on a probable continuation of the Big Lake trend. The well encountered several showings of oil and penetrated an Ordovician section very similar to the productive zones at Big Lake, but was abandoned when sulfur water was encountered at 8041 feet. 2. Gulf Production Co., McElroy No. 103, in the McElroy Field, Upton County. The well was drilling at 8553 ft. at the close of the year in beds of probable pre-Permian age. The test is an important one because it should prove or disprove deep production in the Church-Fields-McElroy pools and also throw geologic light on the deep possibilities of other fields in the western part of the Permian Basin. 3. Humble Oil and Refining Co., White and Baker No. 1, in Pecos County, about 11 miles west of the Yates field. The well is on a nonproductive Permian high and should indicate the deep possibilities of the Yates field. At the end of the year, drilling had progressed to 7200 ft., where beds of pre-Permian age are believed to have been penetrated. The major fields in West Texas, in which present-day proration had its inception, were produced under increased restrictions. A date of importance in the proration history of the area was $ept. 8, 1933, when the Railroad Commission issued an order placing all producing wells under proration. The severe reductions in total outlet made during 1933 were well compensated for by a more than threefold increase in the price of crude oil. Acid treatment was one of the general engineering developments of interest. The work had not progressed sufficie~ltly at the close of 1933

Jan 1, 1934

By F. F. Schmidt, H. R. Ogden, E. S. Bartlett

Continuing tantalum alloy development studies have been concerned with a more detailed investigation of promising binary, ternary, and more complex tantalum alloys containing Groups IV-A, V-A, VI -A. VII-A, and VII-A metal additions. A primary objective of these studies was to improve the elevated temperature strength of tantalum with minimum degradation of fabricability and low-temperature ductility by alloying. Several alloys were found to exhibit hot tensile strengths in the excess of 25, 15, and 10 ksi at 2700°, 3000°, and 3500°F, respectively, combined with excellent cryogenic toughness and ductility. Particularly outstanding in this respect are alloys in the system Ta-Mo-W. Ternary parameter curves describing hot-strength, low-temperature ductility, recrystallization temperature, weld ductility, and fabricability are presented for the Ta-Cb-V, Ta-Hf-W, Ta-Mo-Hf, Ta-Mo-V, Ta-Mo-W, and Ta-V-W systems. At present, only four metals qualify for large scale structural applications at temperatures above about 1800°F. These are tungsten, tantalum, molybdenum, and columbium. Research and development work on these refractory metals has progressed to the point where efforts are now primarily directed toward the improvement of high- and low-temperature mechanical properties through alloying. High melting point combined with excellent low-temperature ductility, fabricability, toughness, weldability, and high solubility and tolerance for both substitutional and interstitial solutes are important attributes of tantalum. Conversely, its high density and relative scarcity compared with other refractory metals are the major deterrents to the use of tantalum. Early studies in the Battelle alloy development program established base line data on the mechanical and metallurgical properties of high-purity tantalum.&apos; These studies were extended to include a preliminary investigation of the effects of various alloying elements on the established base properties.2,3 Recent studies involved a more detailed investigation of promising binary alloys containing Cb, Hf, Mo, Os, Re, Ru, and W, and ternary Ta-Cb-V, Ta-Hf-W, Ta-Mo-Hf, Ta-Mo-V, Ta-Mo-W, and Ta-V-W alloys. Results of major importance obtained are given in this article. EXPERIMENTAL PROCEDURES Electron-beam-melted tantalum (Wah Chang) and high-purity alloying elements were consolidated as 150-g ingots by multiple nonconsumable arc melting under a partial atmosphere of helium. Homogeneity of the button ingots was checked radiographically. Alloy buttons measured about 1-1/2 to 1-3/4 in. in diam by about 0.35 and 0.50 in. thick. Nominal alloy compositions were checked on each alloy button by weighing after arc melting. In most instances, weight losses were within 3 pct of the total weight charged. Subsequent chemical analyses on a number of selected alloys showed interstitial contents to range as shown below: Range of Interstitial Content, ppm 0 C N H 25-75 50-100 10-50 1-5 Metallic alloying additions were found to agree well with nominal compositions based on weight change data. Fabrication directly from the cast button to sheet was conducted at low (75° to 900°F), intermediate (1800° to 2000°F), or high (3000°F) temperatures, depending upon alloy content and hardness. Evacuated stainless steel or molybdenum packs were used for fabrication at intermediate and high temperatures, respectively. The temperature required to complete recrystal-lization in one hour was determined by hardness measurements and metallographic observations (longitudinal test sections) after vacuum annealing at 180°F intervals in the range 2010° to 2910°F. All mechanical property evaluations were conducted on recrystallized sheet, nominally 0.04 in. thick. Weldability of the various alloys was screened using manual TIG welding techniques. Bend ductility (bend axis perpendicular to weld axis) was the criterion used for evaluation. Tensile specimens employed 0.200 by 1 in. gage lengths, and bend test specimens measured about 1 by 1/4 in. Low-temperature tensile tests were conducted using a crosshead speed of 0.02 in. per min up to the point of yielding, and 0.05 in. per min to fracture. High-temperature tensile tests were conducted in vacuum using a crosshead speed of 0.01 in. per min

Jan 1, 1963

By Thomas Brownfield

The chronicle of the oil industry in Oklahoma in 1939 is one of declining production bolstered by strenuous efforts to find new pools or new producing horizons in the older, highly exploited, relatively shallow areas. Production, which averaged 608,000 bbl. daily in 1937, the post-depression peak, declined to 463,000 bbl. daily in 1938 and continued downward to 421,000 bbl. daily for the year 1939. While the state could produce somewhat more oil if demand warranted it, production in most areas is at as great a rate as could be justified on the basis of maximum efficient operation. Outlet for Oklahoma crude has been seriously affected by the increase in production in the Illinois Basin. Crude movements from the Kansas-Oklahoma area to the northeastern consuming centers averaged 314,000 bbl. daily in 1939 as compared with 397,000 bbl. in 1938. Oklahoma producers bore the brunt of this loss of market. The general production decline was accentuated by the August, shutdown of 15 days, precipitated by the action of a major crude purchaser posting a 20-cent reduction in the price of crude. The Oklahoma Corporation Commission, in collaboration with other members of the Interstate Oil Compact Commission, ordered a complete shutdown of all producing wells in order to prevent the premature abandonment of stripper wells, which might result from a prolonged period of production at prices below operating costs. The reduction in price was forestalled, most major purchasers failing to meet the cut in view of the shutdown, and the company initiating the move rescinded its action. Fear of the shutting in of oil wells, especially those making considerable quantities of water, is generally unfounded in the light of a superficial examination of the records. Oklahoma&apos;s unprorated pools, which produced 154,000 bbl. daily in May, declined to 152,000 bbl. in June and 143,000 bbl. in July. Immediately following the shutdown, the same pools produced 150,000 bbl. in September, 145,000 in October, and 145,-000 in November. Thus, while the half month&apos;s production loss in August has not been made up, the wells apparently hare produced at a greater rate since the shutdown than immediately preceding it.

Jan 1, 1940