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By G. R. Mansfield

THE geologic structure of the Idaho phosphate field has an important bearing on the classifica-tion and the exploitation of the lands that contain phosphate. Maps and structure sections1 recently made available show that the phosphate is mainly preserved in downfolded or downfaulted areas. Since the phos- phate beds are generally rather soft and lie between harder and thicker formations they have been forced to adjust themselves to these formations during epochs of disturbance of the earth's crust, so that they are frequently affected by minor folds and by faults which may help exploitation by producing undue thickness at certain places or may hinder it by cutting out the phosphate at other places where according to expecta-tion it should be present. A particularly important structural feature which affects both the distribution and the exploitation of the phosphate beds is the great Bannock overthrust by which one or more slices or blocks of the earth's crust have been pushed over other blocks like ice cakes on a pond. Thus in this region a great flap of folded rocks lies across other rock structures for a distance of approximately 35 miles. Most of the commercially accessible phosphate deposits, shown in the maps that accompany the report cited, are in this flap, which con-stitutes the upper block of the overthrust. In some places, however, the phosphate in the lower block is also accessible. In both blocks post-phosphate rocks exposed at the surface here and there indicate that phos-phate beds may lie at greater or less depth below. The presence of the Bannock overthrust beneath much of the area reported is known by the occurrence of windows in the upper block both within the quadrangles mapped and in areas farther west. The portions of the lower block exposed in these windows show stratigraphic dis-cordance with the surrounding formations. The depth of the fault plane at most places, however, can be told only by drilling or actual mining. Some of the folds in the upper block are relatively deep and it seems fairly certain that the phosphate that may originally have been present in their deeper parts has been removed by thrust faulting. The estimates of phosphate reserves in folds liable to be affected by the Bannock overthrust may therefore need ultimate revision depending on the depth of this fault plane, as it may subsequently be ascertained.

Jan 1, 1928

By M. V. Mielke, R. E. Hagen, R. L. Bennett

FINE IRON ORES, and concentrates such as those produced from taconite, must be converted to lump form by some process of agglomeration before they can be used effectively in the blast furnace or open hearth. At the present time, four major processes for agglomerating these materials are being used on a commercial scale: sintering, nodulizing, pelletizing and briquetting. IN 1945 U. S. Steel Corp. through its subsidiary the Oliver Iron Mining Div., drew up tentative plans for an agglomerating plant on the Mesabi Range which would include a nodulizing kiln and a sintering machine. The purpose of the plant was two- fold: during its initial operation it would provide data on agglomeration of high grade ore fines, and would help relieve the shortage of ore for open hearth charging. Subsequently, it would be available for agglomerating taconite concentrates. While operating on fines screened from direct ore, it was planned to develop techniques and personnel so that a workable plant would be ready to handle taconite concentrates when the time came.

Jan 1, 1954

By C. B. Foraker

THE Magma mine, of the Magma Copper Co., at Superior, Pinal County, Arizona, is 68 miles east of Phoenix and 21 miles west of Miami, Arizona, on highway U. S. 180. TEMPERATURES AND UNDERGROUND WATERS Surface Temperatures.-The average surface dry-bulb temperature at Superior is 72.4°; wet-bulb, 57.4°; with an indicated relative humidity of 38 per cent. The average yearly rainfall from 1921 to 1936, inclusive, was 18.74 in. The maximum condition of the atmosphere is in June, July and August, and the minimum is in January and February. The surface temperatures, of course, influence the temperatures of the down-cast shafts; however, the variation between winter and summer causes a difference of only 2° to 3° in the stopes and working places that are not close to the intake shafts. Average atmospheric conditions are shown in Fig. 1. Rock Temperatures.-Rock temperatures on the deeper levels of tile mine are as follows: LEVEL DEGREES LEVEL DEGREES 2000 109 3200 127 2250 112.5 3400 130 2550 116 3600 134 2800 120 3800 137 3000 124 4000 140 There appears to be no difference in rock temperature for any particu-lar horizon of the various formations or in the vein. Water encountered is always the same temperature as the rock from which it flows, and for this reason it is thought that the water is heated by the rock; not the rock by the water. The country rock apparently has been heated by the various intrusions, perhaps the vein itself, and has not yet had time to cool off. The geothermal gradient (Fig. 2) as indicated by the rock tem-peratures given above is 1 1/2 ° per 100 feet.

Jan 1, 1938

By A. S. Argon, G. East

From their study of the anisotropy of grain boundary mobility in aluminum, the authors conclude that tilt boundaries have a higher mobility than twist boundaries because the atomic misfit at the pure-twist boundary is relatively small compared to the misfit at a tilt boundary for a given amount of misorientation. If this is true, then one would expect a twist boundary to have a lower grain boundary energy than the corresponding tilt boundary. Fig. 6, taken from the work of Gjostein and Rhines,10 shows that this is indeed the case for [001]-cu tilt and twist boundaries in the high-angle region, thus lending support to the authors' conclusion.

Jan 1, 1968

By Bernard MacDonald

Of the treatment of the slime-pulp of gold- and silver-ores by cyanidation, agitation is an essential part. When prepared for treatment, this pulp, consisting of ore reduced to such fineness that approximately 80 per cent. of it will pass through a 200-mesh screen, is mixed with a certain proportion of water, carrying in solution the cluantity of cyanide (KCN) and other chemicals required. The water-constituent of the pulp thus prepared usually ranges from 1 to 2 parts by weight to 1 of the dry ore. Thus constituted, the pulp is charged into treatment-tanks, the shape and capacity of which vary, according to the quantity of pulp to be treated daily and the method of agitation to be employed. Tanks have no other function in a cyanide,plant than that of being economical and corlvellient containers or receptacles for holding the pulp, solutiou, or water used in the operations. It is by agitation that the solids in the pulp charged into the tanks are kept in suspension in, and mixed with, the solution in the proper proportions required for the treatment. If the proper mixture of solution to dolids be determined to be 2 to 1 by weight (which is, approximately, 5 to 1 by volume), this proportion should be maintained in every part of the charge; that is, each solid particle of the pulp, whether it be of' 180- or 400-mesh size, should be surrounded by five times its own volume of solution throughout the whole period of treatment. The reason is, that the amount of chemicals ascertaiued to be necessary for dissolving the gold and silver contained in the solids, is held in uniform solution in the water-constituent of the pulp, and, therefore, the determined proportions of solution and solids must be maintained at all times during treat-

Jan 1, 1912

By G. W. Josephson

VIRTUALLY every year inventors find one or more startling new uses for one of the varied products of the nonmetallic mineral industries. For example, in November a major step toward positive control of rainfall was made when an experimenter converted a cloud to snow by dropping a few pounds of solid carbon dioxide into it. Other examples of ingenuity in the development of markets and production methods are noted in the following pages. For most of the industrial mineral products one of the outstanding features of 1946 has been the high level of production. There are exceptions, such as quartz crystal and lithium, whose production capacity during the war outgrew current peacetime needs, but they are few. Some technical men point out that this prosperity is not an unmixed blessing to technologic progress, because so much effort must go into day-to-day production problems that relatively little opportunity is left for the pursuit of new developments.

Jan 1, 1947

By Don L. Kendall, Martin G. Buehler

A simple physical model has been developed to fit carrier-removal data in silicon irradiated near room temperature with reactor spectrum neutrons. Commonly observed donor and acceptor defect energy levels are assumed to be introduced linearly with neutron fluence. The donor levels (in ev) are Ev + 0.16, Ev + 0.27, and Ev + 0.31 and the acceptor levels are Ec - 0.55, Ec - 0.40, and Ec - 0.1 7, where Ev and Ec are the valence and conduction band energies, respectively. The introduction rates of each level are adjusted to fit literature initial carrier-removal rate data. When normalized with respect to the Ev +0.27 level, the relative values of introduction rates are 5.3, 1.0, 3.1, 1.0, 2.0, and 20.0, respectively for the six levels indicated above. To fit p-f (hole concentration vs neutron fluence) and n-f (electron concentration us neutron fluence) data, the introduction rates are multiplied by a factor which preserves the relative values given above. This factor depends upon irradiation temperature, reactor energy spectrum, neutron fluence calibration, and oxygen content of silicon. An extensive study of the effect of neutrons on carrier-removal in silicon irradiated with reactor spectrum neutrons (E > 10 kev) has been given by Stein and Gereth1 (SG) and Curtis, Bass, and Germano' (CBG). They measured initial carrier-removal rates for both p- and n-type silicon over an impurity range typical of silicon devices. In this work, we attempt to fit a simple theory to this data to establish a usable relationship between hole and electron concentration, p and n, respectively, and neutron fluence f. The p-f and n-f relations are needed to assist in the design of neutron tolerant silicon devices and are needed to clarify presently used empirical resistivity-fluence relationships.3 Neutron damage in silicon produces a variety of defects ranging from simple point defects to defect clusters. For the purpose of this treatment, we assume that simple point defects dominate carrier-removal effects. In contrast to this view, stein4 has proposed that defect clusters are responsible for a significant portion of carrier-removal effects. In the following section, it is shown that the carrier-removal effect in n-type silicon with an electron concentration less than 1015 cm-3 can be explained adequately by assuming that the divacancy is the dominant defect and that its introduction rate is independent of the electron concentration. For electron concentrations greater than 1015 cm-= an additional acceptor defect center is needed, and for simplicity the A-center (vacancy-oxygen pair) has been chosen. Although the E-center (vacancy-phosphorus pair) can account for some of the results, the A-center was chosen because the E-center requires a more involved treatment which the presently available data do not justify. In p-type silicon three radiation-induced donor levels are assumed, namely the divacancy and two other centers of unspecified nature located at Ev + 0.16 ev and Ev to 0.31 ev. The donor divacancy at Ev + 0.27 ev is assumed to be introduced at the same rate in p-type as in n-type. However, this rate is too low to fit p-type initial carrier-removal data. The dominant centers in p-type silicon are assumed to be the Ev + 0.16 ev and Ev + 0.31 ev levels where the latter is not the divacancy. The introduction rates are chosen to fit initial carrier-removal rate data. Assuming that the introduction rates are independent of Fermi level, the ratio between them is fixed for subsequent p-f and n-f calculations. Using the same ratios, the initial carrier-removal rate data1,2 as well as p-f and n-f data1,5 can be fit provided the absolute value of the introduction rates are adjusted to account for irradiation temperature, reactor energy spectrum, neutron fluence calculation, and the oxygen content of silicon. THEORETICAL ANALYSIS This analysis is basically the same as that used by Hi116 to analyze electron damage in silicon except we express the degree to which an impurity level is ionized not in terms of the Fermi level, but in terms of carrier concentration. Landis and pearson7 have used the latter approach to analyze y-damage in silicon. Neutron-induced defects responsible for carrier-removal at room temperature are assumed to be simple point defects with no interaction between defects so that they may be represented by discrete energy levels. It is also assumed that no constituent of a defect complex is used up and defects stabilize shortly after irradiation. Defects are assumed to be introduced linearly with fluence according to the product Rtf where Rt is the defect introduction rate and f the neutron fluence. Taking into account the ionization of defects according to Fermi statistics, and considering charge neutrality where minority carriers are neglected, the n-f relation is where no is the preirradiation electron concentration. The parameter Nt is the electron concentration at which the ionized defect concentration is one-half the total defect concentration (Rtf) or where Et is the defect energy level. For silicon at 300°K, ni = 1.45 X 1010 cm-3 and Ei = Ev+ 0.542 ev which was determined using Ec — Ev = 1.11 ev and me* = 1.07 mo and mh* = 0.558m0. The spin degeneracy factor, which usually appears as a number multiplying the Nt/n term of Eq. [1], is taken as unity. In effect, this factor has been incorporated into the defect en-

Jan 1, 1970

By D. R. Parrish, W. E. Lamoreaux, W. W. Owens

Several methods are now being used by the industry for determining the gas-oil flow characteristics of reservoir rock samples. Most of the laboratory experirnerltal rlzethods can be classified either as steady-state, unsteady-state, or Hassler-type tests. Although the validity of the results obtained by any specific method is not questiorzed, in general, the complexity of these methods leaves much to be desired. This investigation dealt primarily with the development of a simplified unsteady-state (gas drive) laboratory test method for measuring kg/ko re1ationships of small core samples. A procedure for selecting uniform and representative sandstone rock samples was developetl since it was observed that the reliability of the test resu1ts was dependent upon having a sample which was uniform in porosity and permeability. The importance of factors known to influence the results of this type test, such as oil viscosity, gas expansion, and pressure differential were eva/uated. The method of calculating the test results was found to give valid data over a wide range of gas expansion. The limits of pressure differential and oil viscosity which would insure reliable results were defined. In cornparisorz with other presently used testing methods, the gar drive method requires considerably less apparatus, is less time consuming, and is more readily adaptable to a routine type core test. INTRODUCTION The detcrmination of the gas-oil flow characteristics of reservoir rocks has been given concentrated study by the oil industry for the past decade. Both analytical and experimental methods have been considered. The analytical methods have generally relied on a simplified characterization of porous materials in order that the fundamental laws of fluid flow and capillarity could be utilized. More direct experimental methods have been proposed by numerous production research laboratories with the primary goal being a simple and inexpensive, yet reliable method for measuring the gas-oil flow characteristics of reservoir rock samples. The experimental methods which have been reported in the literature generally can be grouped into one of the following classifications: 1. Steady state1,2,3,4 in which a fixed ratio of flowing fluids is forced through the test sample until equilibrium conditions of saturation and pressure gradient are established. 2. Hassler or stationary liquid method5,6,7 in which a uniform liquid saturation is attained, usually through capillary desaturation, then gas or oil is flowed through the sample at a pressure drop insufficient to disturb the pre-established saturation. :. Non-steady state method1,8,9,10 In which only the gas phase is injected into the sample, causing displacement of the oil phase and resulting in a system of continually changing average saturation and saturation gradient. The steady-state and Hassler methods have been most popular because, no doubt, of the simplicity of the actual relative permeability calculations. The problems involved in these methods were limited to apparatus design and measurement techniques. In the steady-state method, for instance, a constant flowing fluid ratio is established which, at equilibrium, results in an essentially uniform saturation over the entire length of the test sample. Therefore, the basic flow characteristics could be obtained by correlating the average saturation of the test sample with the kg/ko determined at various flowing gas-oil ratios.

Jan 1, 1957

By G. F. Loughlin

MORE than 20 years have passed since the publication of Lindgren and Ransome's report on the Cripple Creek District,1 which was made when the district was much more active and prosperous than in recent years. They concluded that the output of the district, which had reached its maximum of about $18,200,000 in 1900, would gradually decline, and their conclusion has been confirmed by records of subsequent production. Between 1905 and 1915 annual declines were partly compensated by encouraging increases, especially in 1908, 1914, and 1915; but a rapid continuous decline followed, due largely to the war and its after effects, until in 1922 the value of output was only slightly more than $4,000,000. It rose to nearly $5,000,000 in 1924, but declined again in 1925 and in 1926, when it was about $4,400,000, and represented ores mainly from deep levels in the Cresson and Portland mines. The profitable operations of these two mines were the principal factors leading to a study of ore at deep levels in the district by the U. S. Geological Survey in coopera-tion with the Colorado Metal Mining Fund. The principal reasons for Lindgren and Ransome's conclusion were three: (1) the greater cost and difficulty of deep exploration; (2) the decrease in the number of veins with increasing depth, and (3) the probability that the telluride ore, believed to have formed at comparatively low temperature, would not persist indefinitely -in depth. Operations since they made these statements have verified the first two, but call for some modification of the third. Rich telluride, ore is being mined at a profit in the Portland mine 3000 ft. below the present surface, or 5000 ft. below the original surface of the Cripple Creek volcano, as interpreted by Lindgren and Ransome. The question arises, therefore, as to the number and extent of such deep deposits, and the answer, so far as it can now be given, must be based mainly on structural data, supplemented by data on the processes of ore deposition. Presentation of these data based on a study of deep mines in the southeast quarter of the district, the only

Jan 1, 1927

By Paul C. Merritt

For more than 100 years, British Columbia has been considered a mountainous mining province, rich with potential but relatively poor in actual production. Times have changed. Today, Japanese interests and money have altered the difficult, if not once impossible, economic conditions and market factors which until recently precluded any great growth of the British Columbia mineral industry. The mining boom now underway in British Columbia has carried the total value of mineral production in the Province to a record height in 1962 as it rang up a 27% increase over that of 1961. Breaking the $200 million barrier for the first time, total value of British Columbia's mineral output reached $229- 276,385. Of this amount, metals accounted for 70%; industrial minerals, 6 %; structural materials, 9 %; and fuels, 15%. The substantial increase is attributed to the record production of copper, iron, asbestos, natural gas and petroleum, in addition to the continuing high production rate and favorable prices of other mineral commodities.

Jan 12, 1963

By R. F. Mehl, C. S. Barrett, A. H. Geisler

THE mechanism by which the super-saturated solid solution of 20 per cent silver in aluminum decomposes has been reported in two previous publications. 1,2 The analysis of streaks in Laue photograms showed that thin platelike particles (the so-called Guinier-Preston aggregates) form upon {111} matrix planes in the early state of decomposition.1 The size of these particles is larger, the higher the temperature at which they form in accordance with nucleation theory;3 at all temperatures they increase in size with aging.2 When they have grown thick enough to afford three-dimensional diffraction, powder X-ray photograms show that the structure is not that of the equilibrium precipitate y but that of a transition lattice ?'. Since this is also platelike in shape and also lies upon the {111} matrix planes with the {110} direction in the matrix parallel to the {11.0} direction in ?', it seems likely that the original platelet particles are merely ?' in an early stage of formation, and thus finely dispersed. The atomic spacing and pattern on the {00.0} plane in ?' are identical with those on the {111} matrix plane to which it lies parallel, and since comparable directions in the two planes are parallel, the lattices are thus coherent at the interface; an analogous coherence has been found in aluminum-copper alloys.3 The structures ?' and y are both close-packed hexagonal and are oriented alike; they differ only in interatomic distances. Consequently, ? ' is regarded as y strained from its ordinary dimensions by the lattice coherency between it and the matrix.2 The lattice movements that transform the matrix to the equilibrium precipitate appear to be very simple.2 The mechanism of precipitation in this system is simpler and is more precisely known than that in any other system,2,4 hence the system should be a profitable one for the difficult task of correlating property changes with structural alterations. The present report provides additional studies on powder X-ray diffraction from alloys of 10 per cent, 20 per cent and 30 per cent Ag, and presents the correlation of crystallographic changes with changes in microstructure, Brinell hardness and electrical resistivity of the three alloys. PREPARATION OF SAMPLES AND EXPERIMENTAL PROCEDURE The preparation of the 20.2 per cent Ag alloy has been described.2 Alloys containing 9.9 and 29.7 per cent Ag were prepared from 99.97 per cent Al and 99.99+ per cent Ag using a similar procedure. Rolled

Jan 1, 1943

By Olav Klomstadlien

The lean, but extensive iron ore deposits of the Dunderland Valley north of Mo i Rana, Norway, are the raw material base for Rana Mines, a division of the state-owned A/S Norsk Jernverk steel mill. The iron bearing minerals are magnetite and specular hematite. The magnetite/hematite ratio varies considerably both within each deposit and from one deposit to another. The ore bodies that lend themselves to mining have generally a thickness of 30-60 m grading 30-35% Fe and 0.15-0.25% P. The grain size varies from 0.05 to 2.5 mm. The fine grained ores are hard while the coarse grained ores are soft and easy to grind. The A/S Norsk Jernverk steel mill operates both a sinter and a pellet plant, and this necessitates production of two types of concentrates. The present flowsheet is shown in [Fig. 1]. The crude ore from the pits is crushed in a 1.07-m gyratory crusher with an open side setting of 12.7 cm. The crusher product is transported by rail to the concentrator located 25 km from the mines. The ore is fed by twelve 1.22 X 1.83 m vibratory feeders onto conveyor belts which carry the ore to a surge bin ahead of the autogenous mills. The feed rate is automatically adjusted to maintain a set power load at a level suitable for the ore type being processed. The mills operate in closed circuit with twelve dual-drum screens equipped with a 0.8-mm screen cloth. Oversize is returned by gravity to the mill feed while undersize flows to the gravity separation section which consists of Humphrey spirals in three stages. The ores are very heterogenous and analysis may vary quite considerably. The quantitative need for concentrate in the steel mill may also change rapidly. The process in the concentrator must therefore be easily changed, and consequently alternative process lines have been established. This is indicated with the dotted lines in the flowsheet. Apatite is removed by flotation by fatty acids to give a final sinter concentrate of 63% Fe and 0.020% P or less. Pellet concentrate contains about 65% Fe and less than 0.020% P. The fineness is about 1500 Blain.

Jan 1, 1981

By G. W. Healy, W. Craft, D. C. Hilty

By means of a theoretical extension of the Cr-C temperature relation in molten chromium steels to low chromium contents and by a correlation of the ratios of chromium to iron in the slag and metal, a method has been developed for estimating the amount of metallic oxidation during the oxidizing period of a chromium steel heat. Application of this method has indicated that due to temperature limitations metallic oxidation may be excessive for very low carbon steels charged with more than a small amount of chromium. IN the melting and refining of chromium steels the oxidation of carbon to a low level is accompanied by the oxidation of chromium and iron in considerable amounts. For the subsequent recovery of chromium and associated iron from the slag, the amounts of metal oxidized must be known for efficient reduction and control of composition. Further, in order to arrive at an accurate understanding of the process, so that chromium-bearing scrap can be used effectively, information is required on the relation between composition of the charge and weight of metal oxidized to reach the desired carbon content. Crafts and Rassbach1 recently developed an empirical relation between chromium, iron, and manganese oxidized per ton of steel charged, and final carbon content and temperature. This relation did not show any dependence on amount of chromium charged. However, it was felt that such a dependence might be present, so a further analysis of the data was undertaken. Cr-C Relation at Low Chromium Levels Crafts and Rassbach's results were based on temperatures estimated from the Cr-C relation previously established experimentally by Hilty,2 and on a single temperature observation (immersion thermocouple) on a heat made at low temperature from a charge of carbon steel scrap containing only a small amount of residual chromium. The temperatures estimated from the Cr-C relation were for heats charged with chromium-bearing scrap and which contained substantial amounts of chromium (2 to 10 pct) at the end of the oxidizing period. No data, other than that from the low temperature heat just mentioned, were available for the low and intermediate chromium ranges. In order to extend the range in which temperature may be estimated, the Cr-C relation requires further consideration. The Cr-C relation, expressed as suggests that carbon is zero at zero chromium in the bath. This is obviously absurd, because as chromium approaches zero the carbon content must approach the limit established by the Fe-C-O equilibrium. It is evident, therefore, that the Cr-C relation as defined by Eq. 1 is not valid below some minimum chromium content that may vary with temperature. On the other hand, it is probable that any such limiting chromium content is less than 4 pct at 3200°F, since the experimental data from which the Cr-C relation was derived included several observations at that level with no deviation. In any event, it is apparent that further evaluation of the results presented by Crafts and Rassbach is dependent upon a means for estimating the Cr-C temperature relation in the low chromium region. From the observations of Chen and Chipman9 and thermodynamic data given in Basic Open Hearth Steelmaking,4 the following relation can be calculated for melts containing small amounts of chromium and carbon assuming a carbon monoxide pressure of 1 atm: % Cr -21,250 K' = (%C)2; logK1 == —t— +13.88 [2] Moreover, by plotting Eq. 2 for any given temperature on cartesian coordinates, it can be extrapolated graphically to the limiting carbon content at zero chromium for the specified temperature without serious complications. By means of Eq. 2 and its extrapolation, the Cr-C temperature relations originally established experi-

Jan 1, 1954

By AIME AIME

T HE appointment of Herbert Hoover to the portfolio of Commerce in the President's Cabinet is to engineers the fulfillment of a long deferred hope to have an engineer in high political office and is a matter of congratulation to us for three reasons; because he is a mining engineer who represents the highest type of idealistic engineering effort; because he is a past president of the Institute; and because he has probably a broader grasp of world problems than any other living engineer. Frank A. Vanderlip in the preface to his book "What Happened to Europe" tells of the many interviews he had with the most prominent men in Europe which were made possible for him by his eminence as a banker and by the courtesy of the American ambassadors. He cites by name such well known figures as Austin Chamberlain, Sir Auckland Geddes, Monsieur Delacroix, Monsieur Briand, Mr. Padkrewski, Mr. Venizelos, Colonel House, General Pershing, Mr. Baruch, and many others and says :

Jan 1, 1921

By D. K. Das, P. A. Beck, S. P. Rideout

IN a previous publication1 1200°C isothermal phase diagram sections were given for the Cr-CO-Ni, Cr-Co-Fe, Cr-Co-Mo, and Cr-Ni-Mo ternary systems, in which the a phase formed narrow, elongated solid solution fields. The present investigation is concerned with the 1200°C isothermal sections of the Co-Ni-Mo, Co-Fe-Mo, and Ni-Fe-Mo ternary systems. A prominent feature of these systems is the presence of narrow, elongated µ phase fields. The crystal structure of the phase designated as µ both here and in the previous publication1 was determined by Arnfelt and Westgren.2 For the (CO, W)µ phase, named by them Co,W, (and also frequently designated as a), these authors found that the crystal system is hexagonal-rhombohedra1 and the space group is D53d — R3,. Westgren and Mag-neli3 later found that isomorphous phases exist in the Fe-W and the Fe-Mo systems (these phases are often referred to as < and E, respectively). Henglein and Kohsok4 stated that the phase described by them as Co7Mo,; (otherwise frequently designated as c) is also isomorphous with the above three. The Co-Fe-Mo system was investigated at 1300°C by Koester and Tonn,5 who found a continuous series of solid solutions between (Co, MO)µ and (Fe, MO)µ Koester6 also indicated similar uninterrupted solid solutions in the Ni-Fe-Mo system. However, since the Ni-Mo binary system does not have a phase isomorphous with F, Koester&apos;s diagram is expected to be erroneous. No data appear to be available in the literature concerning the Co-Ni-Mo system. The face-centered cubic (austenitic) solid solut,ions of iron, nickel, and cobalt, which are quite extensive in all three systems at 1200°C, are here designated as the a phase. The body-centered cubic (ferritic) solid solutions, based on iron, are designated in this report as the ? phase, in conformity with the nomenclature used previously.&apos; Experimental Procedure The alloys were prepared by vacuum induction melting in zirconia and alumina crucibles. The lot analyses for the metals used have been given.&apos; The number of alloys prepared was 46 for the Co-Ni-Mo system, 65 for the Co-Fe-Mo system, and 113 for the Ni-Fe-Mo system. The compositions of these alloys were selected with due regard to maximum usefulness in locating phase boundaries. The alloy specimens were annealed at 1200°C in an atmosphere of purified 92 pct helium and 8 pct hydrogen mixture. Alloys consisting almost entirely of the face-centered cubic austenitic a phase, or of the body-centered cubic ferritic c phase were double-forged with intermediate annealing. The double-forged specimens were then final annealed for 90 hr at 1200 °C and quenched in cold water. Alloys containing considerable amounts of any of the other phases could not be forged. Such specimens were annealed for 150 hr at 1200°C and quenched. Microscopic specimens of all alloys were prepared by mechanical polishing, in many cases followed by electrolytic polishing. Description of the polishing and etching procedures used and tabulation of the intended compositions of the alloys prepared are being published in two N.A.C.A. Technical Notes.7,8 , Many of the alloys were analyzed chemically and, in general, the results are in excellent agreement with the intended compositions. X-ray diffraction samples were prepared by filing or crushing homogenized alloy specimens and by reannealing the obtained powders in evacuated and sealed quartz tubes. After annealing for 30 min at 1200°C the tubes were quenched into cold water. X-ray diffraction patterns were made with unfiltered chromium radiation at 30 kv, using an asymmetrical focusing camera of high dispersion. X-ray diffraction and microscopic methods were used jointly to identify the phases present in each specimen. The amounts of the phases in each alloy were estimated microscopically. The phase boundaries were located by the disappearing phase method. The results were used to construct 1200°C isothermal sections for the three ternary phase diagrams. The accuracy of the location of the phase boundaries determined in this manner is estimated to approximately ±1 pct of each component. The portion of the three phase diagrams lying between the µ, P, and 6 phases on the one hand, and the molybdenum corner on the other, has not been investigated. Recently Metcalfe reported0 a high temperature allotropic form of cobalt on the basis of dilatometric results and of cooling curves. In the present work no attempt was made to search for the new phase in the cobalt corner of the Co-Fe-Mo and Co-Ni-Mo systems. No alloy was prepared with more than 80 pct Co; the alloys used were intended to locate the boundary of the a phase saturated with cL. The microstructures of the quenched a alloys near the cobalt COrner gave no suggestion of an in-suppressible transformation On quenching. The location of the boundaries of the a + ? two-phase fields in the Fe-Ni-Mo and Fe-CO-MO systems was determined entirely by the microscopic method. The face-centered cubic a alloys near the ? field transform partially or wholly into the body-centered cubic ? phase on quenching from 1200°C to room temperature. The ? formed in this manner has an

Jan 1, 1953

CONTENTS PAGE East Texas, except the Gulf Coast-H. Vance 3 Gulf Coast-L. P. Teas 8 Texas Panhandle-C. C. Rae 16 North Central Texas-H. F. Smiley 23 North Louisiana, South Arkansas and Mississippi-B. C. Craft 25 Oklahoma-C. H. Pishny, Raymond M. Carr and E. J. Dickinson 31 Kansas-E. A. Koester 35 Rocky Mountain District-C. D. Johnson 46 Illinois and Indiana-T. Wasson 49 Michigan-T. Wasson 52 Eastern States-P. D. Torrey and W. H. Young, Jr 58 West Texas and New Mexico-W. V. Vietti. Published as a Supplement.

Jan 1, 1933

By Richard L. Ashbrook, John F. Wallace

Several high-temperature eutectics of cobalt and nickel alloys were modified by small additions of selected elements. Thes-e alloys were compared to unmodified melts for microstructural variations. A few modified compositions were selected on the basis of structure and their tensile and stress-rupture behavior determined. The results of stress-rupture tests in air at 1800 F and room-temperature tensile tests of four high-temperature eutectics showed modification capable of producing substantial improvements in properties. The microstructures were altered and mechanical properties improved by: a.) dispersing a subordinate phase more uniformly throughout the matrix; b) replacing large continuous -network or platelike constituents with small equiaxed discontinuous phases; and c) by forming new, finely divided phases. tHE term "modification" is most commonly used to describe the refinement in microstructure of the Al-Si eutectic that occurs as a result of rapid cooling from the melt or on slow cooling after treatment with small amounts of sodium.1 "Modification" has also been used to describe the change from flake to spheroidal graphite in the austenite-graphite eutectic of cast iron.2 This change of graphite shape is accomplished by small additions of cerium or magnesium.3 Other systems have also been shown to be capable of modification, for example: Pb-Sn by copper;4 Al-Cu by sodium;5 Al-Mn by sodium;5 and Pb-Sb by aluminum.5 Although modification of Al-Si alloys and cast irons is usually accompanied by improved mechanical properties, a general definition of modification has been suggested to include the effect of small quantities of impurity elements on the microstructures of all eutectic alloys, regardless of the effect on the mechanical properties.6 In this paper, the term "modification" is employed in a broad sense to include the formation of third phases or even the supplanting of one of the binary eutectic phases by a third phase. The mechanism of modification, as for any solidification phenomenon, must be considered primarily in terms of nucleation and growth. Although both nuclea-tion and growth mechanisms are required to explain all the phenomena observed in connection with the solidification of modified eutectics, various investigators have usually favored one or the other.7"16 It has been shown that modification of a binary eutectic can be effected by addition of a solute element that has greatly different distribution coefficients or k values in the two phases of the eutectic. Under these conditions, differences in the temperatures at the solid-liquid interfaces of the two phases retard the growth of one phase with respect to the other.4 It has also been shown that increased undercooling favors a transition from a rodlike eutectic to a globular eutectic.17 A mechanism proposed for the transition from lamellar to rodlike eutectics depends on the concept of constitutional super cooling.18 The modification of eutectic alloys may be of interest for high-temperature service as well as at room temperature. Although "high-temperature eutectic alloys" may appear to be a contradiction in terms, many eutectic systems, including those studied in this work, have melting points in excess of 2400°F. One of the mechanisms by which high-temperature alloys are strengthened is dispersion of a relatively brittle phase such as an oxide, carbide, or an inter-metallic compound throughout a ductile matrix. For a given volume fraction of dispersed phase, strength is increased by decreasing the size and spacing of the dispersed particles.19&apos;20 Furthermore, room-temperature ductility may also be increased by changing the shape of a brittle dispersed phase from platelike to equiaxed or spheroidal.8 Overaging and redissolving of the secondary phase limit the maximum temperature to which precipitation-hardened alloys can be used. However, in a binary eutectic system, both phases coexist up to the melting point. Although all eutectic structures are not completely stable,21 a dispersion-hardened cast high-temperature alloy might result if a fine distribution of one of the eutectic phases could be obtained during solidification. An additional reason for interest in eutectic alloys is their excellent castability.22 Since eutectic alloys, like pure metals, freeze at a single temperature rather than over a range of temperatures, their castability is superior to solid-solution alloys with long liquidus to solidus ranges. The purpose of this research was to study the effects of small solute additions on the microstructure and mechanical properties of a number of high-melting-point eutectic compositions.

Jan 1, 1967

By Oren C. Baptist, Eliot J. White

Samples of four reservoir sands having different degrees of water sensitivity were subjected to several laboratory tests to determine differences in capillary behavior attributable to clay-mineral effects. The degree of water sensitivity was estimated by the difference between gas and water permeability. Unsaturated pore volumes determined with mercury injection were comparable to irreducible water saturations determined with the semipermeable bar-rier method only for the non-sensitive sands that contained small amounts of non-swelling clay minerals. Irreducible saturations were independent of salinity of the water, which suggests that most residual water is adsorbed 0.7 a film over solid surfaces and that internal retention by clay minerals is relatively insignificant. The water-sensitive sands imbibed water to higher saturations than did non-sensitive sands, and this result is believed to be a combination of the effects of clay minerals and preferential wettability; however, the relative importance of each of these effects is riot determinable. Thus it is concluded that the semipermeable barrier method is the best of the laborafory methods used for estimating formntion water .saturations in the sands studied. INTRODUCTION This investigation is a continuation of studies of the role of clay minerals in petroleum production in the Rocky Mountain area. Previous work has shown large differences in gas and water permeability in numerous reservoir sands; these water-sensitivity effects observed in the laboratory have been correlated with well behavior in the field, and the degree of water sensitivity imparted to reservoirs by the various clay minerals has been determined.&apos;.&apos; The effect of interstitial clay minerals on formation water3 saturations is not so well known. It has been reported that formation water saturations probably are higher in clayey than clean sands,&apos; but this effect has not been evaluated in the laboratory, and the relative effect of the various types of clay minerals on formation water saturation has not been determined. The clay-mineral groups of most importance to this study and to petroleum production in general are kaolinite, illite, and montmorillonite. The minute layers of montmorillonite are loosely bound to one another so that water enters between them, causing great expansion of the particles. Kaolinite and illite do not exhibit interlayer hydration, but they do immobilize considerable amounts of water owing to their large surface areas, which are of the order of 15 to 97 m2/gm of clay.5 The four Wyoming sands used in this study were selected to represent a wide range of water sensitivities. These sands, with the number of wells and fields from which the samples were obtained, are: Second Frontier, five wells in two fields; Newcastle, six wells in one field; Tensleep, two wells in two fields; and Lower Muddy, five wells in one field. EXPERIMENTAL METHODS AND PROCEDURES Water-displacement data were obtained by the semipermeable barrier method," using both fresh water and brines having either 16,500 ppm sodium chloride or calcium chloride. A displacement pressure of 35 psi was found to be sufficient to obtain the practical irreducible water or brine saturation (IWS, IBS) in most samples. Mercury-injection data were ob-tained with equipment and pro-cedures similar to those described by Purcell.7 Exceedingly high pressures are required to attain complete mercury saturation by this method; however, since saturations in most samples change very little with large pressure increases above 1,000 psia, the maximum pressure used was 1,400 psia. To facilitate comparison of mercury-injection and water-displacement results, it is convenient to express mercury-injection data in terms of unsaturated pore volume. The abbreviation, (100 - SHg)min, is used to denote the pore volume unsaturated by mercury at 1,400 psia injection pressure. Gas permeabilities, ki, were deter-mined by the method proposed by Klinkenberg.8 Methods of determining types and amounts of clay minerals by X-ray diffraction analyses, as well as methods of determining water permeability, have been described previously.&apos; The imbibition characteristics of

Jan 1, 1958

By David Turnbull

IN most reactions involving solids the transformation kinetics may be represented by the combination of two processes-those of nucleation and of growth. For example, Mehl and his coworkers 1,2 in their studies on the transformation of austenite to pearlite in steels have been able to describe the kinetics in terms of the rates of nucleation and of growth. By micrographic examination of their specimens they determined the nucleation rate (rate of appearance of pearlite colonies) as a function of time, of percent transformation, and of temperature. They observed that after an incubation period in which no nuclei are observed, the number of nuclei appearing per unit time per unit of untransformed grain boundary area, increases at an increasng rate with time. When recrystallization rates have been interpreted in terms of rates of nucleation and growth and the rate of nucleation determined, an incubation period followed by an increasing rate of nucleation has also been reported. Among the studies in which this phenomenon has been observed are those of Kornfeld and coworkers3 on cold-drawn aluminum wire, of Anderson and Mehl4 on the recrystallization of aluminum sheet, and of Stanley and Mehl5 on the recrystallization of silicon ferrite sheet. The existence of an incubation period during which no nuclei are observed does not appear to have been reconciled with the generally accepted Volmer-Becker theory of nucleation in condensed systems. This theory ostensibly requires the rate of appearance of nuclei to be independent of time. VOLMER-BECKER THEORY In order to form a stable nucleus of a new phase B in a mother phase A, the molecules or atoms of the mother phase must surmount a free energy barrier whose height is determined by the volume free energy change accompanying the transformation and the energy of the surface separating the two phases. The free energy difference between nuclei of various sizes and the molecules or atoms of the mother phase is plotted schematically in Fig I as a function of the radius of the nucleus r. This free energy difference is plotted for two values of the change of free energy per atom, (fB - fA) accompanying the transformation when the volumes of the two phases are infinite. One of these values of (fa-fA) corresponds to a temperature above the temperature To at which the phases A and B are in equilibrium, and the other to a temperature below To. In order for a nucleus of phase B to be stable at a temperature T2 < To, its radius must be equal to or greater than the critical value r* for which the free energy of formation of the nucleus is a maximum, ?f*. Aggregates of phase B having radii equal to or less than r* will be called embryos. Mehl and Jetter,6 in discussing the kinetics of nucleation in solid systems, suppose that embryos of critical size are formed

Jan 1, 1948

By HAROLD VINTON COES

THE motive for merging or consolidation today is conspicuously different from that actuating business men in the late eighties and early nine- ties. Then they combined to secure added productive capacity and to monopolize their respective industries with a view to exploiting the consumer. So flagrant were some of these cases that they brought about their own correctives via retaliation on the part of the public and the subsequent restrictive legislation and legal curbs. The objective of the present-day merger, writes W. R. Hill in Printers&apos; Ink, December, 1927, is summarized as follows : "In the golden days when an industry was being cut to pieces, the prevailing cure was to combine. The reason for such trusts was to strangle competition and by creating a monopoly, dominate the market, raise prices, regardless of economic business methods, and simply force larger profits.

Jan 1, 1930