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By James P. Savely, Victor L. Kastner

Inspiration Consolidated Copper Company is currently mining in four pit areas; Live Oak, Red Hill, Thornton and Joe Bush Extension, near Globe, Arizona. Small satellite orebodies lying outside the main pits have been mined out in a series of small open pits. Major slope instability has affected production in every pit. Some consequences of the instability have been; (1) Serious interruption of mining plans, which resulted in deferred ore production, lost ore, reduced mining rates and increased stripping requirements. (2) Forced replacement of crushing facilities. (3) Serious effects on other production facilities. The introduction of a slope stability monitoring and control function as an integral part of mine planning has been successful in reducing the impact of these failures and will eventually result in economic pit design based on probabilistic slope analysis. This case history presents a brief review of the problems associated with slope instability at Inspiration's mines followed by a more detailed report on one specific failure area in the Thornton pit where the use of horizontal drain holes for slope stabilization appears to be successful. Relationships between slope movement rate, rainfall, and mining activity are shown.

Jan 1, 1983

By C. Schlumberger, M. Schlumberger

In order to explore electrically a terrain composed of a succession of horizontal beds, a current of known intensity i is caused to flow between two grounds A and B, and the resultant drop of potential , caused by the resistance of the earth, is measured between two given points in the soil, M and N. In practice it is convenient to choose the two points M and N so that they lie on the line AB and their midpoint coincides with the middle 0, of that line, although this is not imperative. When the lengths L and I of the two lines AB and MN are varied, equations are obtained which may be solved for the resistivity p of the subsoil at various depths. Recall briefly that the formula 4 x l gives the average resistivity, in the horizontal direction, of a layer of earth which extends to a depth1 about equal to L/4. This elementary concept is adequate for numerous practical applications. Nevertheless, it must be said that, in many cases, a rigorous mathematical analysis may be made, provided it is always a question of homogeneous, superposed horizontal beds. The authors expect to publish, later on, appropriate methods of calculation for some specific cases.

Jan 1, 1932

By CHARLES HOPPER

In preparing the Steep Rock Lake iron ore body for mining, it was necessary to drain Steep Rock Lake. Using diamond drills, a cut 1800 ft long, 100 ft wide, and maximum depth of 95 ft amounting to 300,000 cu yd of material, was excavated in Greenstone to provide a drainage channel. This was done under the general contractor C. A. Pitts, of Toronto, who in turn employed a diamond drill contractor, Boyles Bros., to do the drilling. The method of excavation was selected be- cause a clean square cut and grade could be maintained in the bottom of the channel. Bootlegged holes would have left blocks of rock in the corners which would have created a situation which would have become progressively worse as the open cut advanced from one side of the ridge to the other.

Jan 1, 1949

By A. Steiner, K. L. Komarek

Activities of aluminum in solid Ni-A1 alloys have been determined between 20 and 60 at. pet Al and 1200" and 1400°K by an isopiestic method in which nickel specimens, heated in a temperature gradient, are equilibrated with aluminum vabor in a closed all-alumina system. The activity of aluminum shows a strong negative deviation from Raoult's law at low concentrations but increases by three orders of magnitude within the ß(NiAl) phase. The partial molar enthalpy and entropy of mixing are negative. Using Wagner and Schottky's theory of ordered compounds, a degree of disorder of 4 x 10 -4 for NiAl and 1.25 X 10-2 for FeAl has been calculated THE Ni-A1 system has been studied by a great number of investigators, and the results, as far as the phase diagram is concerned, have been compiled by Hansen.1 The phase boundaries from 0 to 50 at. pet Ni are well-established. At higher nickel contents the boundaries are still in dispute and an additional phase, A12Ni3, has been reported.' The phase diagram is dominated by a very stable high-melting compound, NiA1, with a relatively wide range of homogeneity. Heats of formation of solid alloys have been determined calorimetrically by Oelsen and Middel3 from 20 to 95 at. pet Ni and by Kubaschewski4 from 25 to 80 at. pet Ni. According to the most recent compilation5 no other thermodynamic investigations have been reported for the Ni-A1 system. Due to the corrosive nature and the low vapor pressure of aluminum, a method has been employed for determining activities of aluminum which was previously developed for the Fe-A1 system.= Nickel specimens, heated in a closed evacuated alumina system in a temperature gradient, were equilibrated with aluminum vapor from a source within the system kept at constant temperature. After complete equilibration the specimens were analyzed and activities calculated from the known vapor pressure of aluminum. APPARATUS AND EXPERIMENTAL PROCEDURE Materials. The nickel specimens were made from wafers of electrolytic nickel (International Nickel Corp.) of 99.99 pet purity which were rolled to a 0.001-in.-thick foil by Driver-Harris Co. and to a 0.005-in.-thick sheet in our laboratory. The aluminum (Aluminum Corp. of America) had a purity of 99.99+ pct. The alumina tubes and crucibles were made of impervious recrystallized alumina with an alumina content of 99.7 pet (Triangle RR, Mor-ganite Inc.). Experimental Procedure. Annular specimens were punched from the sheet, the punching burrs removed, and the specimens degreased in carbon tetrachloride and acetone and weighed on a micro-balance to within an accuracy of ±0.01 mg. The specimens were positioned with alumina spacers along an alumina tube, and the positions measured. Aluminum metal was machined into cylindrical shape, and placed into an alumina crucible. The tube with the specimens was then inserted into a hole drilled into the aluminum metal. An alumina tube with its closed end at the top was slipped over the specimens so that its lower end fitted snugly into the alumina crucible. The assembled reaction tube was inserted into a mullite tube with a water-cooled brass head which had an opening for a quartz thermocouple protection tube and a metal-to-glass connection to a conventional vacuum system. A Pt-Pt 10 pet Rh thermocouple could be raised and lowered in the quartz tube which was placed along the outside of the alumina reaction tube. The mullite tube was heated by two separately controlled resistance-tube furnaces so that in the experimental temperature range an over-all temperature gradient of approximately 150o to 250°C could be imposed on the reaction tube. The position of the mullite tube was adjusted so that the surface of the aluminum metal was always at the temperature minimum. The reaction tube was thoroughly evacuated before and during slowly heating the assembly up to the melting point of aluminum. A pressure of less than 2 µ (Hg) was maintained during an experiment. Once the aluminum had melted, it isolated the contents of the alumina tube from the surroundings. Several times during an experiment the temperature gradient was carefully measured. An experiment lasted from 3 to 6 weeks and it was terminated by air cooling the evacuated mullite tube. For further details of the experimental procedure the paper on the Fe-A1 system6 should be consulted.

Jan 1, 1964

By W. M. Robertson

The formation of grain boundary grooves on surfaces of poly crystalline samples of cobalt and iron immersed in liquid lead has been studied. The grooves form by volume diffusion of the solutes cobalt and iron in the liquid. The diffusion coefficients of the solutes in liquid lead are derived from the measured rate of grooving. The diffusion coefficients are described by the relation D = Do exp (-Q/RT), with, for cobalt, Do = 4.6 x 10-4 sq cm per sec and Q = 5300 ± 800 cal per mole, and for iron, DO = 4.9 x 10-3 sq cm per sec and Q = 10,500 ± 1500 cal per mole. LIQUID metal-solid metal interactions occur at solid-liquid interfaces. Interfacial energy provides a driving force to change the morphology of the interface. Mullins1,2 has derived expressions for the kinetics of interface morphology changes driven by capillarity. These expressions can be applied to an isothermal system of a solid in equilibrium with a liquid saturated with the solid. Surface profile changes can occur by volume diffusion of the solute in the liquid, by volume self-diffusion in the solid, and by interfacial diffusion at the liquid-solid interface. A groove will form at the intersection of a grain boundary with a solid-liquid interface, reducing the total interfacial free energy of the system. The solid-liquid interfacial energy ? must be greater than half the grain boundary energy of the solid ?6 for Mullins' calculations to apply. If ? is less than ?b/2, then the liquid penetrates the boundaries, separating the grains rather than forming grooves. Boundary penetration did not occur in the work described here. where CO is the equilibrium volume concentration of the solid in the liquid, Dv the volume diffusion coefficient of the solid in the liquid, ? the interfacial free energy of the solid-liquid interface, O the atomic volume of the solid crystal, k Boltzmann's constant and T the absolute temperature. Eqs. [1] and [2 ] also apply to grooving by volume self-diffusion in the solid,1 with CoODv = D Self, where DSelf is the volume self-diffusion coefficient of the solid. For a grooving mechanism of interfacial diffusion at the solid-liquid interface, the groove width is given by2 where CS is the interfacial concentration of the diffusing species, and DS is the interfacial diffusion coefficient. Eqs. [1] and [3] can be used to determine the mechanism of groove growth. A t1/3 dependence of the growth indicates volume diffusion and t1/4 indicates interfacial diffusion. In some cases, volume diffusion and interfacial diffusion both can contribute substantially to the grooving process, causing the time dependence to be intermediate between t 1/3 and t1/4.3 For these cases, the relative contributions of the two processes can be separated.4 However, in many cases, one process will be dominant, and the data can be analyzed on the basis of Eq. [1] or Eq. [3] alone. The time dependences for volume diffusion in a liquid and volume self-diffusion in a solid are the same. However, the self-diffusion contribution of the solid is usually negligible compared to volume diffusion in the liquid. After the grooving mechanism has been determined, Eq. [1] or Eq. [3 ] yields the kinetic parameter A or B. The kinetic parameter can be used to calculate values for the unknown quantities in the product CD?. Usually C is known or can be estimated. If ? is known, then D can be calculated. In a measurement of grain boundary grooving of copper in liquid lead,' the time dependence indicated volume diffusion in the liquid. The quantities Co, Dv, and ? were obtained from the literature, giving excellent agreement between the observed values of A and the values calculated from Eq. [2 ].5 In a study of the grooving of several refractory metals in liquid tin and liquid silver, A1len6 educed that grooves formed by volume diffusion in the liquid. In a study of nickel in a nickel sulfide melt, Steidel, Li, and spencer7 found volume diffusion grooving kinetics. Both Dv and ? were unknown, so they could not obtain either one separately, though they did obtain a reasonable value for the temperature dependence of the product Dv ?. Several methods have been used to obtain surface profiles. It can be done by sectioning through the interface7 or by chemically removing the liquid from the solid surface after solidification of the liquid.6 However, if the liquid dewets the solid on removing the solid from the melt, then the interface can be observed directly. This method was used previously' and was utilized also in the present study. EXPERIMENTAL PROCEDURE Lead of 99.999 pct purity was obtained from American Smelting and Refining Co. Cobalt sheet was obtained from Sherritt-Gordon Mines, Ltd., with a nominal purity of 99.9 pct, the principal impurities being nickel, iron, copper, carbon, and sulfur. The sheet was

Jan 1, 1969

By Dale A. Vaughan, Oliver M. Stewart, Charles M. Schwartz

Solid-solubility limits at 1500°, l000q and 500°C for carbon, nitrogen, and oxygen in high-purity tantalum were determined by X-ray lattice-parameter methods. For carbon, the solubility was found to be 0.17 at. pct at 1500°C, and less than 0.07 at. pct at 1000°C. A nitrogen solubility of 3.70 at. pct at 1500° C decreases linearly with temperature to 2.75 at. pct at 1000°C, and 1.8 at. pct at 500°C. In the case of oxygen, the solubility was found to be 3.65 at. pct at 1500°C, 2.95 at. pct at 1000°C, and 2.5 at. pct at 500°C. The phases Ta2C, the low-temperature modification of Ta205, and Ta,N of unknown composition but which has a superlattice structure based upon the original bcc tantalum lattice have been identified as the initial precipitates in the respective systems. Metallographic methods were employed to verify the X-ray analyses. The etching behavior of Ta is discussed in terms of lattice i?rzperfections and precipitate phases. The excellent fabricability, high melting point, and nuclear properties of tantalum are responsible for interest in this refractory metal. Data on the solid solubility of the interstitial elements (oxygen, nitrogen, and carbon) in tantalum and on the precipitate phases are somewhat limited. The significant contributions are discussed below. Because the purity of electron-beam melted tantalum (only recently available) is considerably higher than that used in previous studies, the present investigation was initiated. Gebhardt et all-3 have investigated the tantalum-oxygen and tantalum-nitrogen systems with particular reference to the changes in physical properties and to the rates of reaction between these gases and the metal. The solubility of oxygen in tantalum was reported2 to be 3.7 at. pet at 1500°, 2.3 at. pet at 100O°C, and 1.4 at. pct at 750°C. Schonberg4 reported that several oxide phases (Ta40, Ta,O, TaO and Ta,05) exist while X-ray studies by Gebhardtl showed only two oxides, Ta,05 and an unidentified phase which was associated with a platelet-type precipitate. La-gergren and Magneli,' however, questioned the existence of compounds other than the two allotropic modifications of Ta,05 for the tantalum-oxygen system. In the case of nitrogen, the solubility was estab- lished by Gebhardt3 to be of the order of 7 at. pct at 1800°c. The solubility was reported to decrease rapidly with temperature, and, although no limits were established, a precipitate phase was observed by Gebhardt except when the high-nitrogen specimens were cooled very rapidly from the reaction temperature of 1800c. He reported the initial precipitate phase to be a tetragonal distortion of the bcc tantalum lattice while Schonberg6 reported the phase lowest in nitrogen Jo be a cubic super-lattice with a cell size of 10.11 A. Two other nitride phases, Ta,N and TaN, were reported; these appear to be isomor-phous with the carbides of tantalum. The tantalum-carbon system was investigated by Ellinger7 and by Lesser and Braurer. Two compounds, Ta,C and TaC, were reported to exist, each with a range of composition. The solubility of carbon in tantalum was found to be practically nil at all temperatures. Thus, of the interstitial elements which are present in small amounts in high-purity tantalum, carbon might be expected to form precipitates. The present investigation was initiated to obtain additional data on the solid-solubility limits of these interstitials at 1500°, 1000°, and 500' with particular emphasis on the distribution and the identification of the precipitate phases. EXPERIMENTAL WORK AND RESULTS In the present investigations of the solid solubility and of the precipitate phases in the systems tantalum-nitrogen, -oxygen, and -carbon, high-purity tantalum was reacted with high-purity gases, homogenized at 1800°c, and annealed at and quenched from 1500°, 1000,

Jan 1, 1962

By E. Martinez

Samples of chrysocolla, a hydrated copper silicate, from several sources were submitted to differential thermal analysis (DTA) and thermal gravimetric analysis (TGA). Pure samples of chrysocolla are difficult to obtain, but comparison of the thermograms revealed that certain reactions occurred in all the samples and it is believed that these are due to chrysocolla. Endothermic reactions occurred at 50' to 175°C, 350° to 650°C, and 980° to 1100°C each of which caused a weight loss. The first was due to loss of absorbed water, the second to a dehydroxyla-tion, and the last to conversion of cupric oxide to cuprous oxide. In addition, two exotherms were detected at 685° to 695°C and 935° to 950°C. Infrared spectra of heated samples indicated the exotherms were due to changes in the Si-O bonds leading to the formation of cristobalite. The results suggest that thermoanalysis may be a more sensitive and reliable method for detection and identification of chrysocolla than X-ray diffraction, infrared spectroscopy, or optical techniques. The recovery of copper from oxide ores has been the subject of much research in recent years. One of the principal oxide copper minerals is chrysocolla, a hydrated copper silicate. The information available indicates that it has widely varying properties depending on the origin of the sample. Chrysocolla usually is found associated with cuprite, malachite, azurite, and native copper. Most of these other minerals are recoverable by present day flotation practice, but chrysocolla is lost in the tailings.1,2 Reagent combinations that are successful in laboratory chrysocolla flotation with ore from one source have been found to be ineffective with another. 3 The copper segregation process offers an altemative to beneficiation of oxide copper ores.4'5 The process is of particular interest in processing ores that cannot be treated by conventional hydrometal-lurgical methods because of high acid consumption.6 Fuller understanding of the properties of chryso- colla may prove of value in the search for improvements in both the flotation and segregation processes. Chrysocolla samples from Arizona, Nevada, Chile, Australia, and South Africa were studied by differential thermal analysis (DTA) and thermal gravimetric analysis (TGA). In addition, a sample from Miami, Ariz., was submitted to X-ray diffraction, infrared spectrophotometry, and surface area determination. EQUlPMENT Differential thermal analysis (DTA) detects, amplifies, and records exothermic-endothermic reactions occurring in a sample as its temperature is raised at a constant rate, usually 10°C per minute. A unit made by the Robert L. Stone Co. was used in this study. The tests can be run if desired with a gas streaming through the sample. A thermobalance records weight losses or gains in a sample as its temperature is raised at a uniform rate. The gravimetric analyses (TGA) were run on a Chevenard thermobalance converted electronically for graphic recording. A heating rate of 5°C per minute up to 1100°C was used in these tests. A Perkin Elmer Infrared Spectrophotometer, Model 221, was used with sodium chloride optics obtaining IR spectra in the 2 to 15 region. A pressed pellet technique with potassium bromide was used in preparing the samples. DESCRIPTION OF SAMPLES Chrysocolla is found in the oxidation zones of copper deposits commonly associated with malachite, azurite, and limonite. It is described as varying in composition and in color from bluish green to brown or black. Inclusions of other minerals are usual so chemical analysis of chrysocolla samples may be suspect. However, it is considered by many to be a solid solution of CuO, SiO2 and H2O with a general formula of CuO.SiO2.2H2O or 2CuO.2SiO2. 3H20. Chukhrov7 has described a sample from the Urals as CU3,5(OH)2 (A1Si3) O10.nH2O and stated that chrysocolla is a montmorillonite-type mineral. On the basis of X-ray analyses, DTA, and infrared spectra of chrysocolla from the Inspiration Mine, Ariz., Sun8 concluded that there was no substantial evidence to classify it as a montmorillonite mineral. Chrysocolla samples from many sources throughout the world were used in this investigation. The following is a brief description of each:

Jan 1, 1963

By William T. Folwell

The Lucky Friday mine east of Mullan, Idaho, is an outstanding example of a property in the Coeur dlAlene district where a small and insignificant-appearing silver-lead-zinc vein at the surface has changed at depth into a large vein of great importance. The Lucky Friday vein has little if any surface expression and above the 1200 level the ore shoots are small and discontinuous. Between the 1200 level and 2450 level, the lowest developed level, the main ore shoot has shown remarkable improvement on each succeeding lower level, and today the mine is one of the major lead-silver producers in the Coeur d'Alene district. History: The Lucky Friday property is on the north side of the South Fork of the Coeur d'Alene River in sections 25, 26 and 35, T. 48 N., R. 5 E., Hunter mining district, Shoshone County, Idaho. This is about one mile east of the town of Mullan, which serves the eastern portion of the Coeur d'Alene district. The southern part of the property is crossed by a branch line of the Northern Pacific Ry. and by U. S. Highway 10. This highway is the principal road crossing the panhandle of Idaho and connects the district with Spokane, Wash., on the west and Missoula, Mont., on the east. The main portal and surface plant of the Lucky Friday mine is at an elevation of 3365 ft, only a short distance above the valley floor and a few hundred feet from U. S. Highway 10. so the mine is readily accessible for year-round operation. The property is comprised of six claims, known as the Lucky Friday group, owned outright by the Lucky Friday Silver-Lead Mines Co. There are four patented claims, Good Friday, Lucky Friday, Northern Light, and Lucky Friday Fraction No. 2 (Mineral Survey No. 3028), and two unpatented claims, Hunter and Creek. In addition, Lucky Friday owns an undivided one-half interest in the Hunter Creek property. which adjoins the Lucky Friday group on the north: a 90 pct interest in the mineral rights in the Jutila Ranch (160A), which adjoins the Lucky Friday group on the east; and a 60 pct interest in the Lucky Friday Extension claim group, which adjoins the Lucky Friday group on the west. The company also has a long-term mining lease on the Hunter Ranch, which adjoins the Lucky Friday group on the west. The claims of the Lucky Friday group were located between 1899 and 1906. The Lucky Friday Mines Co. was organized in 1906 and did considerable exploration work by surface trenching and shallow underground workings, only to see the property sold by the Shoshone county sheriff to satisfy labor claims totaling $2000 in 1912. Another firm, Lucky Friday Mining Co., bought the claims in 1914 and spent 12 years driving what is now known as the tunnel level crosscut. This tunnel intersected a vein previously exposed in a higher tunnel, but it was only a few inches wide. The vein was followed a short distance westerly but was so unpromising that the work was discontinued in favor of extending the main crosscut tunnel several hundred feet north. No ore was found and all work was discontinued. The property was held in such low esteem by the firm that it let taxes amounting to less than $15 a year go delinquent for nine years. Then the property lay idle for two more years until in 1938 John Sekulic, a Mullan service station operator, took a lease, with a $15,000 purchase option, on the advice of an old miner who had worked in the mine. Sekulic re-opened the tunnel level crosscut and explored the vein with an easterly drift for about 200 ft. The vein was too narrow to be of commercial value but was believed interesting enough to warrant further exploration at depth. Lacking funds to explore the vein at depth, Sekulic tried to get the district's larger operating companies to take over his lease and option. They were not interested because of the lean tunnel level showing and the fact that the property lay between the White Ledge fault on the north and Osburn fault on the south, an area which geologists always considered unworthy of exploration. Sekulic then organized the present company and assigned his lease and option to it for stock. This was in 1939. Enough stock was sold locally to finance sinking of a shaft 100 ft from the tunnel level east drift. The vein at this additional depth still was not commercial but showed some improvement. Treasury stock was offered at 5 to 10C a share

Jan 1, 1959

By J. W. Pugh, J. D. Nisbet

F. B. Foley—The use of data published by Wever and Jellinghaus in 1931 to fix boundaries of the sigma phase in the Fe-Cr system, in the face of the author's own references to the suggestions of Bradley and Goldschmidt, Aborn and Bain, and Hougardy that the phase is much more extensive, and the very much more accurate work, which weighs heavily in favor of these suggestions, of Cook and Jones, published in 1943 and evidently disregarded by the authors, makes their derived ternary diagram, especially fig. 15 for 400°C, quite inaccurate on the Fe-Cr side and affects the extent of phase boundaries in the most controversial and important part of this ternary system. In commercial Fe-Ni-Cr alloys the occurrence of sigma has been observed time and time again at lower chromium contents than that of the 24 pct Cr, 16 pct Ni, 60 pct Fe alloy which is the lowest permitted by fig. 15 of practically carbonless metal. Newel1 reports sigma in 27 pct Cr-Fe even with some carbon present to be one of the greatest detriments to its extensive application, whereas Pugh and Nisbet set a low limit of 36 pct Cr for sigma in the binary Fe-Cr system. J. J. Heger—The diagrams presented by the authors do not agree with observations made on commercial Fe-Cr and Fe-Cr-Ni alloys, nor do they agree with two recent investigations made on the Fe-Cr and the Fe-Cr-Fe systems. I refer first to the investigation made by Cook and Jones1' on the sigma region of the Fe-Cr system. On the basis of their results which were published in 1943, Cook and Jones established new boundary limits for the sigma and the alpha plus sigma regions. These new limits have been accepted and are incorporated in the Fe-Cr diagram that appears in the 1948 edition of the Metals Handbook. This diagram is shown here as fig. 34. As will be noted, the boundary limits of the alpha plus sigma region in this diagram extend to much lower chromium contents than do those in the diagram presented by the authors in fig. 2. These new limits indicate that sigma phase should form in an Fe-Cr alloy containing 26 pct Cr, and experience with commercial alloys confirms this finding. Indeed, recent studies on a commercial Fe-Cr alloy containing 17 pct Cr have shown sigma phase to be stable in this alloy at 550°C. I recognize that the authors' work did not include studies on the sigma region; however, I believe this is a serious omission because sigma phase may profoundly affect the physical properties of these alloys and should be evaluated in any investigation which attempts to relate physical properties to the equilibrium diagram. The second investigation to which I refer is that made on the Fe-Cr-Ni system by Rees, Burns, and Cook,'' who used pure alloys and employed heating 17 W. P. Rees, B. D. Burns, and A. 3. Cook: Journal Iron and Steel Institute. (July 1949) 162, Part 3. p. 325. times that extend to 200 days. These investigators published their results in July 1949 and from these results constructed isothermal sections at 800" and 650°C. The isothermal section at 650°C is shown here as fig. 35. This diagram indicates sigma phase should form in a pure 18 pct Cr-8 pct Ni alloy. Although sigma phase has not been observed after 10,000 hr at 1200°F in commercial 18-8 alloys containing carbon and nitrogen, it has been observed under the same conditions in 18-8 alloys modified with titanium and columbium, both of which serve to reduce the effect of carbon and nitrogen. This section and the one at 800°C suggest that the constant iron sections which are presented by the authors, should be considerably altered, if they are to represent an accurate picture of the system. A few of the suggested alterations are as follows: In fig. 9, the section at 50 pct Fe, the gamma plus sigma region should be widened, not narrowed at 800" and 650°C. In fig. 10, the section at 60 pct Fe, the gamma plus sigma region should be widened at 800° and 650°C. In fig. 11, the section at 70 pct Fe, an alpha plus sigma, an alpha plus gamma plus sigma, and a gamma plus sigma region should be added. In fig. 12, the section at 80 pct Fe, the alpha plus gamma region should be widened at 800°C. In fig. 13, the section at 90 pct Fe, the alpha plus gamma region should be widened at 650° and 800°C. Undoubtedly, the chief reason for the discrepancies between the authors' data and those of Rees, Burns, and Cook is that the authors did not employ long enough heating times to allow for transformation. In this connection, I wish to warn that transformations in these alloys, particularly transformations at temperatures below 800°C, are extremely sluggish and may require a year or more to approach completion. Therefore, unless extremely long heating times are employed or steps are taken to accelerate these transformations by such means as mechanical working, the results will not yield an accurate picture of the alloy system. Certainly, an accurate picture is needed for the development of better high-temperature materials. E. J. Dulis-The purpose of this work is not clear. If an improvement of the ternary equilibrium diagram of the Fe-Cr-Ni system was wanted, it seems logical that testing techniques superior to those previously used would be a prime requirement. To approach equilibrium in this system, long holding times are needed; a fact established long ago but apparently ignored by the present authors, who used the continuous heating and cooling tests in equilibrium studies. A publication on the same system by Bradley and Goldschmidt6 was criticized by Monypenny in a

Jan 1, 1951

By CHARLES F. DEISS

The total pipe-line runs of petroleum in Indiana during 1945 were 4,114,000 bbl., a decline of nearly 17 per cent below the estimated 4,950,000 bbl. produced in 1944. Drilling activity during the year was centered in Posey and Gibson Counties, where seven new pools were discovered in the state. Four of the pools are in Posey County-Crunk, Farmersville, Jeffries and St. Wendells East-and the other three are in Gibson County-Johnson West, Lysle and Mt. Carmel East.

Jan 1, 1946

By R. E. Cech, J. H. Hollomon

KURDJUMOV and Maksimova reported experiments with manganese steels and high carbon steels' and with an Fe-Ni-Mn alloy' in which mar-tensite was formed isothermally over a range of temperatures. They found in some cases that mar-tensite formation could be suppressed by rapid quenching to liquid nitrogen temperature. From their microstructural observations of martensite formed isothermally, they concluded that the rate controlling step is nucleation rather than growth. Kulin and Cohen,3 in an attempt to reproduce these experiments, found that with a steel having the same composition as that reported by Kurd-jumov and Maksimova, the transformation to martensite was essentially complete above the temperature range of Kurdjumov and Maksimova's isotherms. The possible reasons for this disagreement were not considered. Recent papers by Das Gupta and Lement4 and Kulin and Speich5 report the formation of isothermal martensite in a high chromium steel and in an Fe-Cr-Ni alloy, but neither paper can be considered a verification of the original Kurdjumov and Maksimova results. Further, in neither case were the authors able to suppress the formation of martensite entirely. Because of the important bearing the Kurdjumov and Maksimova results have to an understanding of the mechanism of martensite reactions it was felt that an experimental investigation directly concerned with checking the validity of their results was in order. This paper describes the results obtained on the isothermal transformation over the temperature range from —79" to —196°C of an alloy of iron, nickel, and manganese. Experimental Apparatus A 15 lb heat of an alloy containing 73.3 pct Fe, 23.0 pct Ni, and 3.7 pct Mn was melted by induction and cast under argon. The ingot was forged to 1-in. bar and a portion rolled to 1/16x1 1/2-in. strip. This strip was pack-homogenized 300 hr at 1100" in a helium-filled sealed iron tube. The composition after homogenization was 73.2 pct Fe, 22.94 pct Ni, 3.73 pct Mn, 0.05 pct C, and 0.015 pct N. The strips were cut to 1/2-in. width for dilatometer and metal-lographic specimens. Only the center portion of the 11/2-in. strip was used in the present investigation. The dilatometer employed was similar in design to one described by Flinn, Cook, and Fellows." A concentric fused auartz rod and tube assembly with hooks for holding the specimen was mounted so as to transmit the specimen dilation to a 1/10,000 in., 1/10 in. travel dial gage. The dilatometer proper was mounted by means of extension arms to a counterweighted sliding member on a vertical standard. This method of mounting permitted rapid transfer of the dilatometer from the austenitizing furnace to the quenching bath and low temperature chamber. A small electrical vibrator on the dilatometer kept frictional effects of the quartz members at a minimum. The austenitizing unit was a vertical, molybdenum-wound, hydrogen atmosphere furnace maintained at a constant temperature ±3°C by means of constant power input. A 12-in. stainless steel jacketed copper liner having 1/2-in wall thickness acted to equalize the temperature in the hot zone of the furnace. This liner, closed at the bottom end and open at the top to permit entrance of the dilatometer and specimen, was kept filled with dry nitrogen gas. A chromel-alumel thermocouple was placed inside the tube to determine the temperature. The 4-in. dilatometer specimens in the chamber varied less than 1/2° across the specimen length except for a 1 1/20 drop at the end nearest the open end of the furnace. The low temperature isothermal holding bath was a double Dewar arrangement similar to one described by Turnbull7. The outer bath was filled with a refrigerant at a temperature lower than the desired holding temperature. The inner bath was filled with Freon "11" or "12" or a mixture of both, depending upon the holding temperature. This inner bath which tended to be cooled by the outer bath was kept at a constant temperature by introducing a small amount of heat with a manually controlled electric heater. Stirring was accomplished by bubbling dry air through the bath. A Leeds and North-rup type K potentiometer was used to measure the inner bath temperature as indicated by a five element copper-constantan thermopile. The bath temperature was maintained within ±0.2°C of the desired temperature by occasionally adjusting the heater current so as to keep the Leeds and Northrup galvanometer at zero deflection with a constant setting of the potentiometer. Isothermal tests were usually continued for 300 to 400 min and another reading made at approximately 1000 min if the bath, unattended overnight, had not deviated in temperature more than 5°C. Transformation curves are drawn dashed (Fig. 1) through the time region where temperature was not controlled precisely. Experimental Procedure Dilatometer specimens of 1/2x1/16-in. strip were cut to 41/2-in. length and holes were drilled for the quartz hooks with proper spacing to give a 4-in. measured length. A thermocouple consisting of 0.012-in. diameter chrome1 and alumel wires was spot welded to the specimen and threaded between the dilatometer rods to binding posts near the dial

Jan 1, 1954

By ALEC CROWELL

Mississippi has had oil production for only the past six years and natural gas production of minor magnitude since' 1926. The search for oil and gas commenced in 1903 and 1496 wells had been drilled in search of oil and gas up to Jan. 1, 1946. As the year 1945 ended, 659 wells were producing oil and gas from 23 separate reservoirs. The production for the year was 8,353,719,000 standard cubic feet of natural gas measured on a pressure base of 15.025 lb. per sq. in. abs., 15.316,009 bbl. of oil¬field water and 19,093,766 bbl. of crude oil and condensate. Production for the year 1944 was 2,636,067,000 standard cubic feet of gas, 14,979,793 bbl. of salt water and 16,420,346 bbl. of crude oil and condensate.

Jan 1, 1946

By G. C. Wallick

Since the appearance of the paper, "Solution of the Equations of Un-steady State Two-Phase Flow in Oil Reservoirs," by W. J. West, W. W. Garvin, and J. W. Sheldon,' a two-fold investigation of this subject has been carried out. One objective of the investigation has been to deter-mine the feasibility of solving such problems 7on a medium-size com-puter such as the Datatron*, and the other objective has been to in-vestigate the application of such cal-culations to experimental and theo-retical petroleum reservoir research. In the first Datatron calculations, the fluid and rock properties published by West, et al, were used, together with the published equations describ-ing the system. Details of the formu-lation not given in the original paper are discussed in the Appendix to this note. Reference should be made to the subject paper for the complete equations and defintion of symbols. An unexpected result of this in-vestigation was the discovery that the linear solution published by West was in error. Thus, in addition to describing the Datatron solutions and to discussing certain numerical diffi-culties which will be encountered if one uses the published method of solution, the purpose of this note is to indicate the nature of this error. LINEAR FLOW Since the linear case requires a minimum amount of scaling, a fixed-decimal point Datatron program was written for the one-dimensional flow problem and an attempt was made to duplicate the solution described by West. In the case described, fluid was produced at a constant rate, Q, until such time as well pressure reached 0.04. Production was then continued at constant pressure. From the constants and curves given by West it was determined that the ini-tial constant production rate could be approximated by Q = 0.007. An ini-tial dimensionless time step ?t = 0.434 X 10 - "as used, and each suc-cessive time step was doubled until a value of = 0.444 was reached. This constant interval was then used for the remainder of the solution. In subsequent solutions, several varia-tions in the time schedule were em-ployed, including smaller time steps and slower rates of increase in the time steps. In all cases, almost identical results were obtained regardless of the time schedule employed. However, as described below, it was noted that the time schedule had some influence on the rate of convergence of the solutions. As a check on the accuracy of the solution, the cumulative production at each time step was calculated using the two methods described in the Appendix. Satisfactory agreement was observed with the differences in these two values of the order of two parts in 50,000. It should be noted that the mass balance check as described is of questionable value, particularly with regard to the well pressure and saturation. This is especially true in the radial solution where pressure and saturation values near the wellbore would make only a negligible contribution to the numer-ical integration. It is believed, how-ever, that such a comparison is ot value in determining the over-all accuracy of a solution. In comparing the Datatron solu-tion with that published by West it was discovered that in the later stages of depletion, the pressures near the well declined more rapidly in our solution than in the West solution, and that the limiting well pressure of 0.04 was reached at an earlier time than that originally reported. It thus became evident that it would be impossible to duplicate the production schedule described by West and a constant rate of production was maintained until the well pressure was equal to 0.0. A representative comparison of the results published by West with those obtained in this investigation is shown in Fig. 1, which is a plot of GOR as a function of cumulative recovery. These two curves should be in agreement until a cumulative recovery is reached which corresponds to a well pressure of 0.04 — for the Datatron solution, a recovery of approximately 5.6 per cent. Actually, a major disagreement is evident. Subsequent correspondence

Jan 1, 1958

By AIME AIME

UNQUESTIONABLY the Coal Division has never had a meeting in which so many outstanding technical papers were presented of immediate practical application to problems of personnel, mining, safety, preparation, combustion, and carbonization. Should there have been those present with the lingering idea that all that was needed for success in the coal industry was a strong back and a weak mind they must have had a rude awakening.

Jan 1, 1942

THE illustration below shows the design of the face of the clock to be erected as a memorial to the American engineers who gave their lives overseas in the World War. It will be placed in the tower of the library at Louvain, which has been rebuilt through contributions from America. Large clocks seldom have figures on their faces, and each hour on this one will be marked by a gold star, the four faces containing 48 stars, one for each State of the Union. Contributions toward the memorial have been received from every one of the States, and from Alaska and Hawaii as well, but additional subscriptions are invited by the Com-mittee which is arranging for the memorial.

Jan 3, 1928

By New kensington P. A, W. L. Fink, H. R. Freche

The investigation of aluminum alloy systems prior to 1923 was severely handicapped by the low purity of the best aluminum available. However, by that time, the electrolytic purification of aluminum had been developed by the Aluminum Company of America,(1)† and in May, 1923, there was initiated, under the direction of E. H. Dix, Jr.,(2) a program for the investigation of the aluminum-alloy systems using the purest electrolytically refined aluminum. Up to the present time 15 papers (3) have been published, most of which are on the binary aluminum systems. Work is now in progress on the ternary systems, and it seems probable that most of the future work will be on ternary systems. Therefore this survey of the binary aluminum systems investigatcd up to the present time (the sixteenth paper of the series) concludes the first phase of this program. Certain qualitative relations between corresponding portions of the various binary diagrams as well as between different parts of the same diagram were noted some time ago by R. S. Archer.(4) In the present paper these relations and others are considered quantitatively by the application of well-known thermodynamic equations or by newly discovered empirical relations. No attempt will be made here to present the history of the development of the thermodynamic equations defining equilibrium or their application to metallic systems, although a list of references is given at the end of this paper for those who are interested in this phase of the subject. Two thermodynamic equations, which will be employed extensively in this paper, are: loge x1 = - L/RT + C

Jan 1, 1934

By H. M. Day, C. H. Mathewson

THE constitution of the system silver-mercury has attracted the attention of many investigators during the last two decades, but since their results are for the most part in poor agreement, there is little need for a review of their individual contributions. It remained for the very careful thermal and microscopic investigation of Murphy' in 1931 to give the constitutional diagram in its present and unquestioned form, which is shown in Fig. 1. He devised methods for taking cooling curves on alloys under high pressures and for the microscopic observation of alloys which contained liquid mercury as a structural constituent at ordinary temperatures. The compositions of the intermediate phases were confirmed and supplemented through X-ray analyses by Preston2 and Stenbeck.3 According to Murphy, at 276° C. silver is able to dissolve 44 to 45 weight per cent of mercury, which may increase at lower temperatures to about 50 per cent. Preston concluded that the saturation boundary occurred at 46 ± 2 per cent at 100° C. From the values reported in the literature, these are the only ones that may be accepted as lying even in. the right region. PREPARATION OF ALLOYS The silver used in the present investigation was supplied by the United States Metals Refining Co. through the courtesy of the Committee on Industrial Uses of Silver and, since a complete spectrographic and chemical analysis was furnished, no attempt was made to purify it or to further establish the impurities present. The analyses reported by the company are shown in Table 1. Milligan4 has found that the magnesium content is probably less than 0.0005 per cent.

Jan 1, 1938

By W. A. Hoyer, G. A. Lock

Laboratory and field tests have shown that it is feasible to log for copper in a qualitative way using the techniques of neutron activation analysis. Laboratory tests showed that the 0.51 and 1.04 mev gamma rays of 62Cu and 66Cu, respectively, could be diagnostic. However, in the core holes, the detection of copper was limited to 0.3% concentration because of interferences from the 18Si and Al gamma rays. Both stationary and continuous logs were made, but only the stationary data yielded a recognizable copper response. This response consists of a combination of two effects-the direct response from copper at 0.51 mev and an increase in low energy gamma ray absorption due to mineralization. Both low energy chemical (PuBe) and high energy accelerator neutron sources were used for the laboratory and field tests, while the same 2 X 5 in. Nal scintillation detector served for all the tests. Potential improvements in copper detection might be possible with solid state gamma-ray detectors which have better gamma ray resolution but much less detection efficiency. This type of activation logging requires complex equipment and trained personnel to conduct field operations and may find application where coring is difficult or prohibitive.

Jan 1, 1973

By W. H. Chang

The phase identification results on several Mg-base alloys are presented. These results have been correlated with strength data and microstructural studies to indicate that carbide dispersion may contribute significantly to raising the recrystallization temperature and strength of Mo alloys. Evidence is presented to show that the degree of carbide dispersion, and hence the extent of strengthening, is governed by the "metal/carbon" ratio which, in turn, depends on both the carbon content and the presence of stable -carbide-forming alloying elements. IN recent years, Mo-base alloys containing small additions of C, Ti, and/or Zr have been developed, which exhibit much higher recrystallization temperature and strength than those of unalloyed Mo. The superiority of these alloys undoubtedly results from simultaneous operation of more than one strengthening mechanism. In the present paper, the strengthening effect of carbide dispersion will be discussed. Although the role of carbide dispersion is being increasingly recognized, the nature of the carbides has, to the author's knowledge, not been well es- tablished. In Table I are presented some of the phase identification results on representative Mo alloys. These results have been obtained by X-ray diffraction of residues electrolytically extracted from an ethyl alcohol solution containing 7 pct HC1.

Jan 1, 1961

F A. THOMSON, president of the Montana School of Mines, gave an interesting talk on mining schools of the past, present and his ideas of the future before a recent meeting of the Montana Section of the A. I. M. E. He covered the history .of the various mining schools and com- pared the three main types of schools; those attached to or forming part of an endowed college or university such, for example, as' the Columbia School of Mines, the Mining Department of the Massachusetts Institute of Technology and the Mining Department of Stanford University. These resemble in a general way the second class, those attached to the state universities and colleges. The schools of this general type have had varied success.

Jan 1, 1928