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By Lo-Ching Chang, Kenneth M. Goldman

INTRODUCTION THE kinetics and mechanism of transfer of a constituent across a slag-metal interface are fundamentally important because many metallurgical processes involve the existence of a slag phase and a metal phase. Industrial processes seldom proceed to equilibrium, and information of the rates and modes of reactions are therefore often of greater practical importance than equilibrium data. A study of the kinetics of sulphur transfer across a slag-metal interface under reducing conditions will contribute a great deal toward a better understanding of desulphurization in the blast furnace process. The general principles existing in the transfer of a constituent, such as sulphur, across a slag-metal interface can be extended to similar transfer phenomena in other metallurgical processes. The present paper will demonstrate how such studies will lead to fruitful results from both the practical and theoretical standpoints. EXPERIMENTAL METHOD The apparatus used was simple. A graphite crucible 1 5/8-in. id, a wall 1/8-in. thick, and a depth of 4 in., was packed in an outer fused silica tube with powdered magnesia. The crucible assembly was rotated at a speed of 235 rpm inside an induction coil. A charge of 250 g of Armco ingot iron was introduced into the graphite crucible and melted by induction heating. The melt was held at a desired temperature [ ] for 3-5 min., after which 7.5 g of granular ferrous sulphide was added and the bath was held for another 3-5 min. A metal sample was then taken by means of a fused silica tube and a rubber suction bulb. Immediately after the metal sample was taken, 30 g of a prefused and crushed slag were introduced. The slag reached the temperature of the furnace in 1 to 1 1/ 2 min. Slag

Jan 1, 1948

By William C. Harrigan, William D. Nix

Dynamic measurements of Young's modulus have been made for poly crystalline Ni-W alloys from room temperature to 800°C. The alloys studied range in composition from pure nickel to Ni-10 at. pct W. The results indicate that Young's modulus decreases linearly with temperature above the Curie temperature. The rate of change of Young's Modulus with temperature mas found to range from 104 psi per "C for pure nickel to 0.82 x 104 psi per °C for Mi-10 pct W. At all temperatures the elastic modulus decreases with increcrsing tungsten content up to 1 at. pct W, and increases as the tungsten content is increased above that level. Young's modulus decreases slightly as the carbon content is increased from 0.002 to 0.09 wt pct C THE knowledge of the elastic modulus of metals and alloys is important for a number of reasons. The first and most obvious reason comes from the need to predict elastic deflections under given loading conditions. A second and somewhat more subtle reason comes from the fact that the elastic properties of an alloy must be known before a proper account of the mechanisms of plastic deformation can be made. This is especially true for high-temperature creep of crystalline solids. Sherby and his coworkers have shown that the high-temperature steady-state creep rates of crystalline solids are inversely related to the elastic modulus1,2 and that the temperature dependence of the elastic modulus must be taken into account if reliable determinations of the activation energy for creep are to be made. In addition, measurements of the elastic constants of solid solutions are needed to allow one to assess the modulus interaction contribution to solid-solution Strengthening.3-5 Pelloux and Grant6 have demonstrated that substantial solid-solution strengthening at room temperature and elevated temperatures occurs when refractory metal solute atoms are added to nickel. While the high-temperature elastic properties of pure nickel have been measured by a number of authors,7-10 the elastic properties of nickel-based refractory metal alloys have not been determined. The purpose of this paper is to report on measurements of Young's modulus of polycrystalline Ni-W alloys at elevated temperatures. It is expected that these measurements will be valuable to studies of the mechanical properties of nickel-based refractory metal solid solutions. I) EXPERIMENTAL Young's moduli of polycrystalline samples were determined by a dynamic method in order to reduce high- temperature anelastic and plastic relaxations. The samples were forced in transverse free-free vibration; that is, both ends of the sample were unrestrained and the vibration was transverse to the long axis. The fundamental resonant frequency was determined by the Forster method.11 The analysis of this type of vibration which was formulated by Rayleigh,12 Timo-chenko,13 and pickett,14 and reviewed by Fine," leads where fn is the resonant frequency of the nth mode, r is the radius of the circular cross section. L is the specimen length, ßn is 1.5056 for free-free vibration in the fundamental mode of vibration, 6 is the mass density, and E is Young's modulus in the axial direction. This equation can be transformed into: E = 9.17605 x 10-6(L/D)E/Lf2 [2] where E is Young's modulus in psi, L is the length in inches, d is the diameter in inches, W is the weight in grams, and f is the resonance frequency in cps. Eq. [2] was further modified in order to take account of the thermal expansion of the samples. The resulting correct term is: where the thermal expansion coefficients for nickel and tungsten, respectively. Xw is the atom fraction of tungsten in the sample and T is the temperature in "C. The treatment of the thermal expansion coefficient as a linear function of composition seems sufficiently accurate since an error of 25 pct in the expansion coefficient will result in only a 0.3 pct error in the modulus at 1000°C. A) Apparatus. The equipment for this investigation has been described by Lytton et al.16 Several modifications of the equipment have been made. The most significant change involved replacing the detector crystal transducer with a magnetic transducer. A phonographic magnetic transducer was employed as a sensing device since the contact pressure necessary to produce a stable signal is much less than that for a crystal transducer. This magnetic transducer is also not affected by conditions of high temperature and vacuum which are present in these experiments. The vacuum was 10-5 torr at room temperature and about 5 x 10-4 torr at 900°C. This was sufficient to prevent surface contamination of the samples during the tests. The samples were heated in an elliptical furnace with a quartz lamp at one focal line and the sample at the other, as described by Lytton et a1.16 The temperature of the sample was measured by monitoring the

Jan 1, 1969

By J. J. Jonas, J. L. Uvira

Equipment was constructed which permitted the hot compression of 99.8 pct Armco iron and 2.8 pct Si steel at constant true strain rates of 0.05 to 1 per sec over the temperature range 600" to 1000°C. A maximum true strain of 1.9 could be attained, followed by immediate quenching or by isothermal annealing. True stress-true strain curves were obtained, and the steady-state flout stress, a, strain rate, i, and temperature, T, were found to fit the following expression: The constants A, a, n', and AH were determined for the two ,materials. The activation energies obtained for Arrnco iron and silicon steel are 66 and 80 kcal per mole, respectively, and approximate those for seu- diffusion and for creep. This indicates that hot compression is a diffusion-controlled thermally activated process. THE hot compression of iron and steel is usually carried out in the austenite temperature range,1"7 as this is the one of greatest interest with respect to industrial hot working. However, a disadvantage of testing in the austenite range is that the hot-worked structure is destroyed by the phase transformations taking place during cooling. The present study was therefore carried out in the ferritic temperature range, and the hot-worked substructures were preserved by rapid quenching after deformation. The substructural results will be described in a separate paper, and the present communication is restricted to the strain rate/stress/temperature relationship observed during hot working. The results of hot-compression testing are usually given in the form of true stress/true strain curves, with a different curve for each temperature/strain rate ~ornbination.',~,~ Sometimes simple algebraic equations are fitted to the curves, so that certain extrapolations or interpolations can be performed.1'2'5 These equations are, however, devoid of mechanistic interpretations. The present study was undertaken to show that hot compression can be described by an equation of the type used in creep studies. That is, it will be shown that the temperature dependence of the strain rate in hot working is well-represented by an Arrhenius term, with an activation energy similar to that for creep. Also it will be seen that the stress dependence of the strain rate is similar to that for creep EXPERIMENTAL METHOD AND MATERIALS The investigation was carried out with the following three ferrous materials: 1) Armco iron; 2) Armco iron with 0.26 pct Mn; 3) 2.8 pct Si steel. The first two materials were utilized for investigations performed in the temperature range 600" to 800°C; the last one was used for tests at temperatures from 600" to 1000°C. The materials were of commercial purity,* as shown in Table I. Cylinders of five different sizes were prepared by strain annealing. The resulting mean grain diameter was 3 mm in the 1-in. Armco iron and 2 mm in the other sizes and grades. Different ratios of diameter/height were used to enable the determination of the coefficient of friction. The specimen faces were provided with concentric grooves, which acted as lubricant holders during compression, as recommended by English and ~ackofen' and others.2'9 Powdered glass lubricants were applied to the samples before hot compression to decrease friction and barreling, following the practice of previous investigator~.~~~~~~~~ Different mixtures of glass powder were used for each temperature, after the determination of suitable compositions by experiment.'' Equipment for Hot Compression. Hot-compression tests were carried out on an adapted 150-ton vertical hydraulic extrusion press and also on a modified high-temperature creep machine. The modified extrusion press was used for temperatures up to 800°C. The following items were added to the press: a) a high-temperature furnace with built-in upper and lower platens; and b) a transmission assembly, which permitted the attainment of logarithmically decreasing crosshead speeds. These accessories are described in detail in Ref. 11.

Jan 1, 1969

By E. R. Macgregor, J. Halpern

The kinetics of the reduction of cupric salts in aqueous solution by molecular hydrogen to metallic copper are described. The rate of reduction appears to be homogeneously determined and shows a marked inverse dependence on the hydrogen-ion concentration. Precipitation of copper is more rapid and complete in sulfate than in per-chlorate solution. A mechanism is proposed which accounts for this behavior. IN recent years a number of important hydro-metallurgical processes have been developed in which metallic salts in aqueous solution are reduced by gaseous hydrogen, usually at elevated temperatures and pressures, and thereby precipitated either in metallic form (e.g. Ni, Co, Cu) or as an oxide or salt of lower valence (e.g. VO, and VA).1 ; In connection with applications such as these, most of which involve heterogeneously catalyzed reactions, recent demonstrations"-" that salts of certain metals, e.g., Cu", Ag' , Hg" , and Hg,+ can activate molecular hydrogen homogeneously and thus catalyze hydrogenation reactions in aqueous solution, are of considerable interest. For example, cupric salts catalyze the otherwise slow homogeneous reduction of dichromate and ceric salts by hydrogen, i.e. Cr,O; + 3HL. + 8H1 ? 2Cr'- -- 7H,O [1] 2Ce ' ! H.. ? 2Ce" | 2H . [2] In perchloric-acid solution, where Cu" is not appreciably complexed, the kinetics have been found" " to be of the form -d [H,] _- k,[HJ [CU"]' dt -LCu+' l+ (k ,/k,) [H] [3] where, K = 1x10"' exp [—26,600/RT] 1, mole-' min-' ... [4] and (k ,/k,) - 0.25 at 110°C. This kinetic behavior suggests that the reaction proceeds by a mechanism involving the following sequence of steps kt Cu" +H1CuH' 4-HA [51 k., CUH + CU" ? + 2Cu f H' [GI 6Cu'+ Cr,07 + 14H'+ 2Cr- (¦ 7H,O + 6Cu" ['i] fast The catalytic activities of the undissociated cupric-sulphate and cupric-acetate complexes are somewhat greater (by factors of 6.5 and 120, respectively) than that of the simple hydrated Cu" ion.'" These considerations suggest that, in contrast to the other hydrometallurgical hydrogenation reactions, referred to previously, reduction of cupric salts in aqueous solutions by molecular hydrogen, should proceed homogeneously, and in the absence of an extraneous catalyst. This has already been demonstrated" for acetate-buffered solutions where the product of the reaction is a precipitate of cuprous oxide (Cu,O). In the present paper, an investigation of the reduction of cupric salts in perchloric-acid and sulphuric-acid solutions, leading to the precipitation of metallic copper, is described. Some results for the sulphate system, which is of considerable hydrometallurgical interest, have been reported previously by Ipatieff",' " and by Schaufel-berger' but these do not give a quantitative account, of the kinetics and mechanism of the reaction. Experimental The reduction experiments were conducted in the 1-gal, titanium-lined autoclave described in connection with earlier related investigations," " and using a similar procedure. The solutions were made up by dissolving known amounts of CP grade Cu(ClO,), and HC10, (or CuSO, and HISO,) in dis-tilled water. While in the autoclave, the solution was stirred and maintained at a constant temperature (±loc) and under a constant partial pressure of hydrogen gas. It was ascertained that the agitation (provided by two 3-in., four-bladed stirrers, rotating at 900 rpm) was adequate so that at no time was the rate of reaction limited by solution of hydrogen. During each experiment, samples of the solution were withdrawn periodically, allowed to cool, and the concentration of copper remaining in solution was then determined electrolytically. Some Cu' is formed during the reaction, but undergoes disproportionation when the solution is cooled to room temperature. For purposes of kinetic calcula-

Jan 1, 1959

By W. F. Domis, F. von Gemmingen, F. Garofalo

The effect of rain size on the creep behavior of an austenitic iron-base alloy has been studied at 1300° F under conditions of constant stress. The average grain diameter varied between 9 and 190 p (ASTM 10.7-2). The subgrain size and apparent activation energy for creep were not found to depend in any systematic manner on gain size. Grain hozmdary serrations were observed in all specimens tested. The variation of the secondary-creep rate, 2,, with the pain diameter, 1, is given by: es = K(213m + 1 )/l.]; 1, is the grain diameter zohere is reaches a minimum. Results in the literature shoujthat 1,increases as the temperature increases. At low creep temperatures is is therefore proportional to 12, at intermediate temperatures <, exhibits a minimum, and at high creep temperatures is is proportional to 1/1. The dependence ofis on the stress, u, is given by: t, = A" (sinh acrln, a and n show little variation with 1. The dependence of A" on 1 is given by: A" = KA[(21k + 13)/1]. For 1 » >>lmn = 4, and at constant values 01- isat lozu stress levels, the steady-state stress is given by the Hall-Petch relation. The variation of c, with grain size is believed to he associated particularly with grain boundary generation of dislocations which becomes more important with increasing temperatures. SEEMINGLY inconsistent experimental findings have led to a certain amount of confusion concerning the effect of grain size on creep behavior. The confusion is attributed to a lack of test results obtained over sufficiently wide ranges in grain size, stress, and temperature. Experimental results presented in this paper and results available in the literature1-5 show a consistent behavior and lead to a unified concept for the dependence of secondary-or steady-state creep rate on grain size. In accordance with this concept, which is substantiated experimentally, secondary-creep rate should increase with increasing grain diameter at low creep temperatures, leading to greater creep strengths for fine-grained materials. At intermediate temperatures the secondary-creep rate should decrease to a minimum and then increase as the grain size is increased. At high creep temperatures the secondary-creep rate should decrease with increasing grain size, leading to greater creep strengths for coarse-grained materials. Whether a temperature is high or low for creep in a metal or alloy depends primarily on its melting temperature. MATERIAL AND TEST PROCEDURES The material tested was an austenitic iron-base alloy of the following composition (wt pct): C, 0.005; N, 0.017; Mn, 1.26; Ni, 14.21; and Cr, 17.18. Two 15 -lb ingots were forged and hot-rolled to 5/8-in.-diam bars which were then cold-rolled and cold-swaged to a diameter of 0.49 in. These were sectioned into 3-in.-long blanks and heat-treated at various temperatures to obtain different grain sizes. The procedures employed and the results obtained are summarized in Table I. The secondary treatment at 1400° F followed the primary treatment without intermediate cooling to room temperature. This final treatment was employed to minimize various effects arising from heating to different temperatures during the primary treatment, particularly differences in intragranular dislocation structure, segregation of interstitial atoms at grain boundaries, and density of grain boundary ledges. The intragranular dislocation structure was examined by electron transmission metallography after each of the treatments described in Table I. Isolated dislocations and a few tangles were observed but no evidence of subgrains was found after any of the treatments. No grain-size effect was evident on the density and distribution of dislocations. Stabilization of grain boundary structure is particularly important because, as will be discussed later, grain boundaries influence high-temperature creep behavior. Magnetic-permeability measurements after each treatment and

Jan 1, 1964

By Nestor Torres-Acuña, Fathi Habashi

Metallic copper of purity equal to commercial electrolytic copper is deposited during the anodic dissolution of technically available white metal, Cu2S, in m acidic solution of&apos; copper(II) sulfate as electrolyte and copper sheets as cathodes. The process may be applied on commercial scale since it has the advantage of by passing the converting and poling steps, decreasing pollution problems due to SO, and recovering the sulfur of the white metal in the elemental form. The anodic dissolution is believed to take place in three steps: The working conditions that lead to 98 pct cathodic current efficiency are: 30 gpl Cu2+ and 100 gpl H2SO4 in electrolyte, current density 1.0 amp per sq dm, and tetnperature of bath 40°C&apos;. DURING the smelting of copper, nickel, lead, and zinc sulfide ores, large amounts of sulfur dioxide are produced. Because the release of this gas in the atmosphere causes pollution problems, many attempts were made in the past for its recovery either in liquified form or processed to sulfuric acid. Although these two forms of sulfur are the usual forms that are consumed by the chemical and metallurgical industries, their storage and transport usually raise economic problems. It was realized, long ago, that a process by which sulfur can be recovered directly in the elemental form would be most attractive. Elemental sulfur is easily stored and transported, and is readily converted to SO2, H2S, or H2SO4 when needed. Processes aimed to recover the metals from their sulfide ores, and at the same time by-product sulfur in the elemental form, were recently reviewed.&apos; As early as 1882, Marchese2 patented a process in which a matte having the composition: Cu 15, Pb 14, Fe 41, and S 25 pct was electrolyzed. According to cohen3 the process was applied on a pilot scale by the Aktiengesellschaft fur Bergbau-, Blei-, und Zinkhiitten-betriebe at Stolberg, Rheinland, Germany. The process was unsuccessful, however, owing to the contamination of the electrolyte during electrolysis. Studies in this field were reported by Bernfeld4 and Egli.5 Borchers et a1.6-8 developed the process further by using white metal (Cu 78.2 pct, S 19.6 pct) instead of the matte, and a pilot plant was operated by the Mansfeldschen Kupferschiefer Co. at Eisleben, German~.~ It appears, however, that the process never went into commercial operation. Further studies in this direction were carried out by Russian workers.10-23 The International Nickel Co. of Canada erected a pilot plant at Port Colborne in 1951 to apply the process to nickel matte which is essentially pure nickel sulfide."&apos;- 26 Full-scale plant went into operation at the Thompson Refinery in Manitoba in 1964.27 In this method nickel sulfide matte is melted and cast into anodes analyzing 76 pct Ni and 20 pct S with small amounts of copper, cobalt, and iron. These anodes are then electrolyzed in an aqueous solution of NiS04 at pH 4. Further work on this method was reported in the literature.28-31 In this paper, experiments on the anodic dissolution of white metal in aqueous copper sulfate solution are reported. EXPERIMENTAL White metal, Table I, obtained from The Anaconda Co., was cast in form of anodes 10 by 7.5 by 1 cm, Fig. 1. The anodes are mechanically strong and do not break easily; when polished they gave a shiny gray metallic appearance. From the chemical composition shown in Table I, it can be seen that the atomic ratio Cu:S corresponds approximately to the formula CU2.06S. The copper in excess to the formula Cu2S is most probably present as a separate phase since metallic copper could be seen under the microscope, Fig. 2. Fig. 3 shows the X-ray diffraction pattern of white metal which matches fairly well with that of reagent-grade Cu2S.

Jan 1, 1969

By M. J. Sinnott

WITH the advent of nodular iron as an engineering material, considerable interest has been shown in developing this material for various applications. Generally the strength, hardness, or ductility are the more common properties used for design purposes but occasionally applications involving a knowledge of the thermal conductivity of the material is required. A search of the literature showed, rather surprisingly, that relatively little work has been done on this property for all types of cast iron. Insufficient data are available on thermal and electrical conductivities to develop the Weidemann-Franz ratio, or the Lorentz relationship, for estimation purposes. There are no data on nodular irons and the published data on malleable irons are quite sketchy. For these reasons the conductivity of the group of nodular irons listed in Table I were measured. Irons I to IV were made in such a fashion as to maintain the carbon and alloy content essentially the same while varying the silicon content. Test specimens were cut from the mid-section of 4-in. keel castings. Iron V is a commercial casting of nodular iron. The test specimen of this iron was cut from the center of a large cast billet 3x10x26 in. All alloys were tested in the as-cast condition. A microstructural examination showed that each iron had spheroidal graphite but the size and distribution varied with the silicon content of the iron. The spheroid size decreased while the number of graphite nodules increased as the silicon content of the iron was increased. The matrix structures of each iron consisted of pearlite and ferrite with the proportions varying from predominantly pearlite in the low-silicon iron to mostly ferrite in the high-silicon iron. The commercial heat, iron V, was predominantly pearlite probably because of its higher manganese and phosphorus content. Two methods for measuring the thermal conductivity were used. The first was a modification of the techniques described by Powell and Hickman and Van Dusen and Shelton,² the second method was a simpler technique described by Jakob and Hawkins." Since the agreement of both methods as tested on two sets of duplicate samples was excellent, the simpler experimental technique was used. The results of the measurements are given in Table II along with a summary of the microstructural constituents. These conductivity data indicate that as the percentage of silicon increases there is a corresponding decrease in the thermal conductivity even though the structure is changing from pearlitic to ferritic. Such a change in microstructure is usually accompanied by an increase in conductivity. A third factor involved in the behavior of these irons is the size and distribution of the graphite nodules. The relative amounts of graphite do not change greatly but the size and distribution do. Generally graphite improves the conductivity but in the present case such an effect is probably masked by the alloying effect from the silicon and its dispersion through the matrix. The thermal conductivity of the nodular irons studied is less than that of regular foundry irons by some 10 to 30 pct and is less than that of regular malleable irons.&apos; The cause of the decreased conductivity is probably the more highly alloyed fer-rites obtained in these irons and the changed mode of distribution of the graphite as compared to the regular foundry irons. References R. W. Powell and M. J. Hickman: Journal Iron and Steel Inst. (1946) 154, No. 2, p. 99. &apos;M. S. Van Dusen and S. M. Shelton: U. S. Bur. Standards Journal of Research, RP668 (1934) 12, p. 429. ³M. Jakob and G. A. Hawkins: Elements of Heat Transfer and Insulation. 2nd Ed. (1950) New York. John Wiley and Sons. &apos; J. W. Donaldson: Journal Iron and Steel Inst. (1933) 128, No. 2, p. 255.

Jan 1, 1954

By J. L. Brimhall, R. A. Huggins, M. J. Klein

IN a recent paper1 it was shown that small additions of magnesium, copper, and oxygen decrease the stacking fault probability in plastically deformed silver. Correlation of :X-ray data with measurements of the twinning frequency and metallographic observation of slip lines indicated that this effect may be due to an increase in the relative stacking fault energy. It is the purpose of the present note to report experiments on these alloys of known stacking fault probability that relate to the stacking fault contribution to electron scattering in silver. There has been a considerable amount of disagreement in the literature concerning the contribution of dislocations to electrical resistivity in metals. Calculations relating to the scattering of conduction electrons by the dislocation core, its strain fields, and related effects have been made by several authors.2-5 In addition, experimental work on Cu,3,6-10 Ni,11 and Ni-Co alloys1:! has shown that dislocations in those materials exert an anomalously large effect on resistivity, this effect being related to the presence of extended dislocations. The problem of the scattering due to the stacking fault region between partial dislocations has been treated theoretically using several different procedures.13-&apos;0 The results of these calculations show a wide range of predicted values, from rather large to completely negligible, due to the models and the approximations involved. Almost all of this work has been applied to the specific problem of scattering in copper. The more complete theoretical treatments depend rather critically. on the shape of the Fermi surfaces and the effective mass parameters. The scattering from stacking faults might therefore be expected to vary significantly from one metal to another. Unfortunately, sufficiently accurate information is not available .which would allow one to have any confidence in a theoretical prediction of the scattering in the case of silver. Resistivity measurements were made on small wire specimens of vacuum melted high purity silver and several dilute alloys. These measurements were made at approximately 20°C, with great care being given to temperature measurement and corrections. At such temperatures phonon scattering is significantly greater than imperfection scattering. However, the experimental technique was such that measurements on similarly treated samples were reproducible to better than 2.4 X 10-9 ohm-cm, which was satisfactory for this work. Values of the stacking fault probability and the increase in resistivity after severe plastic deformation are given in Table I. The increases in resistivity resulting from plastic deformation agree quite well with previous work on silver.14,21-26 In addition, it has been previously found that interetitials and vacancies in silver anneal out well below room temperature, so that the residual imperfection scattering in these experiments could be expected to be primarily associated with dislocations;. It is seen from the data in Table I that large changes in stacking fault probability are accompanied by differences in resistivity due to imperfection scattering of only a few percent. If the scattering of conduction electrons by extended dislocations is primarily due to the area of the stacking fault region independent of the stacking fault energy, and not the core and strain fields associated with partial dislocations, the resistivity increase should be proportional to the product of the dislocation density and the stacking fault width, as is the stacking fault probability. Therefore, the imperfection scattering caused by plastic deformation of the alloys should be considerably smaller than that found in the pure silver. Since this was not observed, these results sugegest the possibility that stacking faults do not themselves contribute appreciably to the electrical resistivity of silver deformed at room temperature. An alternative explanation of these observations is that the scattering by the stacking fault is roughly proportional to the stacking fault energy, rather than being determined by the total area of such faults. Sufficient evidence is not yet available to separate these two possibilities. This work was supported by the Office of Naval Research.

Jan 1, 1962

The following is an incomplete list of members and guests who called at Institute headquarters during the period Oct. 10, 1918 to Nov. 10, 1918. J. Carson Adkerson, Virginia. George H. Parsons, Hayden, Ariz. Andrew B. Armstrong, Connecticut. W. E. Pomeroy, New York. Courtenay DeKalb, San Francisco. Ezra C. Rider, Bisbee, Ariz. Clifford G. Dennis, San Francisco. H. W. Seaman, Chicago, Ill. Rudolph Emmel, Boston, Mass. William Allen Smith, Northampton. Emil Gathmann, Baltimore Md. R. K. Stockwell, Salt Lake City, Utah. Ernest S. Geary, Denver, Colo. W. G. Swart, Duluth, Minn. W. E. Hopper, Washington, D. C. Kirby Thomas, New York. W. Spencer Hutchinson, Boston, Mass. - Warren D. Thompson, Harvard Club. E. W. Kohl, Jr., Philadelphia, Pa. H. Vincent Wallace, Los Angeles, Cal. E. C. Nighman, Butte, Mont. Paul T. Benson, formerly with the Tacoma smelter, has resigned his position there to accept one with the Great Metals Mining and Milling Co. at Nespelem, Wash. Prof. Edward E. Bugbee, of the Mining Department of the Massachusetts Institute of Technology, has been granted a leave of absence to accept the position of Assistant Director of Education for the S.A.T.C. of five southern states with headquarters at Raleigh, N. C.

Jan 12, 1918

By Ervin E. Underwood

IT has been recognized for many years that dis-persed particles have great value in raising the creep resistance of metallic alloys. In fact, some of the most successful high-temperature alloys owe their superiority to this factor above all others. A recent observation by Glen1," indicates that even better high-temperature resistance to deformation results in alloys capable of two successive precipitation reactions. The ramifications of this finding are of great interest. Unfortunately, our understanding of the reasons for such notable improvements has not kept pace with technical developments. In an effort to uncover some of the basic facts governing strengthening by particles, a program was initiated at the Battelle Memorial Institute with the primary goal of comparing creep strengths in single-phase and two-phase (precipitating) alloys. The effects of precipitation from solid solution on the creep properties of alloys are generally such that the resistance to creep is increased. However, if alloys are heat treated to different degrees of hardness before creep testing, it is often found that those possessing the maximum hardness initially do not necessarily have the maximum creep resistance. Depending on the stresses and temperatures involved other structures may prove more desirable. Considerations of the above nature indicate the importance of defining the initial state of the alloy. Here, it was decided to start with quenched single- phase alloys in which precipitation and creep deformation proceed concurrently. Equipment and Experimental Procedures Preparation of the Specimens—Four 25 lb ingots were prepared from 99.999 pct Cu and 99.996 pct Al to compositions of 1, 2, 3, and 4 wt pct Cu. Spec-trographic and chemical analyses are listed in Table I. After heat treatments and intermediate reductions, the alloys were cold rolled to 1/8 in. thick sheet. The final cold reductions amounted to 50, 40, 20, and 10 pct for the 1, 2, 3, and 4 pct Cu alloys, respectively. The specimens for creep testing were machined into tensile flats 7 in. long, 3/4 in. wide (at the shoulders), and 1/8 in. thick. The reduced sections were 1/4 in. wide and 21/2 in. long. After heat treatments at 540°C to an ASTM grain size of 1 1, the specimens were quenched into water at room temperature, then electropolished in a glacial acetic acid and perchloric acid solution. The gage marks were Knoop impressions placed 2 in. apart on the reduced sections. Blanks of 1 x 1 in, were cut from the same sheets for the age hardening runs and were given the same grain size heat treatments. The specimens and blanks were stored in a refrigerator at —40°C until needed for testing. Creep Measurements—Creep tests were conducted in a constant temperature room which was maintained at 26° ±1°C. A split-type, hinged, vertical-tube furnace was mounted on a horizontal track so that the specimen could be enclosed suddenly. Thus, it took about 15 min for the specimen to come within 5°C of the test temperature. The temperature variation along the specimen was controlled to about

Jan 1, 1958

By Robert J. Linney

In the latter part of the year 1943, it was decided to experiment with diamond-drill blast holes in the Old Bed magnetite mine at the Mineville mines of the Republic Steel Corporation, in sections of the ore body where vertical dimensions were large and where development for sublevel bench stopes had already been done. Other possibilities of application for this drilling method were in the reclamation of old floors and pillars in the pitching folds of the Lower Old Bed ore body and in the reclamation of large vertical pillars in the "21" Bonanza-Joker ore body. The cross sections and views of the two ore bodies will show the conditions to which the diamond-drill method has been applied. The Lower Old Bed magnetite ore body is lenticular and dips approximately 30° toward the southwest and strikes generally southeast and northwest. An intensely folded structure, which pitches generally on an axis approximately at right angles to the strike, is continuous from the uppermost old workings down to the present bottom of the mine, and probably continues with depth. On successively lower levels this folded structure becomes greater in vertical dimensions and the two folds are closer together in a horizontal dimension. As shown in Fig. I, this folded structure gives to parts of the ore body considerable vertical dimensions, which provide areas that were developed for sublevel bench stoping above a slushing drift, as shown in Fig. 2. It was in one of these previously devel-oped sublevel bench stopes, No. 26 on the 1185-ft. level, that the diamond-drill blast-hole method was applied for mining the upper sublevel. The lower sublevel was underhand-bench-drilled to the finger raises of the scram drift below. The roof of this stoping area began to break and spall on the lower sublevel, causing the roof to become inclined. Along the hanging wall of the stope this reached an elevation about half way between the two sublevels. A smooth schistose seam in the hanging wall causes the ore to break away freely. Therefore, if bench mining had been carried on in the upper sublevel, a dangerous condition of poorly supported benches would have resulted. When the drillers were slashing across the sublevel te footwall and hanging wall to make a bench, spdlling roof of the opening below would probably have carried away part of the bench, and would have left a dangerous place in which to continue underhand benching. A 6 by 8-ft. raise had been driven between the lower stope and the upper sublevel about 200 ft. from a manway. It was decided to use this raise for a starting cut and to arrange holes as shown in Fig 3, so that a slot would be opened across the ore body between the footwall and hanging wall. This slot would then be used for the purpose of breaking into the ore, by blasting vertical rings of holes drilled at right angles to the axis of the pitching folds as nearly as possible. Layouts of this slot drilling and the rings adjacent are

Jan 1, 1946

By E. L. Kinsella, F. S. White

Solids fluidization utilized in two ways for the commercial production of lime is described. Crushed —6 mesh limestone is dried and dedusted in a single bed reactor, then calcined in a 5-stage reactor. Construction, operation, and results obtained with both processes are given. THE solids fluidization process brought out by the Standard Oil Development Co. in the early forties for catalytic cracking of petroleum enabled rapid transfer of large quantities of heat from gases to solids under closely controlled temperature conditions. As the technique developed, it was natural that applications for the process outside the petroleum industry would be sought. The calcination of limestone to quicklime requires the transfer of a large quantity of heat at high and closely controlled temperatures. For these reasons, this possible application was one of the first to be investigated. Laboratory work conducted by the Dorr Co. indicated that lime produced by solids fluidization would be of exceptional quality. Calculation of theoretical heat balances showed that savings in fuel could be expected. Accordingly, a pilot plant of 10 tons per day capacity was erected by the New England Lime Co. at Adams, Mass., to substantiate the process. Operation of the pilot plant, previously described,&apos; showed that excellent lime could be produced with a saving in fuel. The work also indicated the necessity of preparing feed to remove the finer fractions if dust losses were to be held to a tolerable level. A single-stage fluidized solids drier-stripper was developed to accomplish this sizing.&apos; Subsequently a commercial lime reactor was erected at Adams, beginning operation in June 1949, followed by air sizer facilities completed in November 1951. This paper will describe these two applications of solids fluidization. The raw material for preparation of lime by the fluidizing process is a high calcium crystalline lime- stone having the approximate chemical composition shown in Table I. The stone is first prepared by crushing and grinding in conventional equipment to pass a 6-mesh sieve. After crushing, the material is sent to the FluoDry unit for drying and dedusting. Fluidized Drying and Sizing As shown in Fig. 1, the FluoDry unit consists of a -in. cylindrical steel shell, 9-ft ID by 22-ft 6-in. overall height. Attached horizontallv at the bottom is a 6-ft diam combustion chamber, approximately 7 ft 6 in. long. A refractory constriction dome, consisting of first-quality fire brick shapes, partitions the inside into two sections. The lower section is called the windbox and the upper the bed compartment. The vertical wall of the shell is lined with 6-in. first-quality rotary kiln blocks. In the bottom of the windbox a hoppered section is formed with castable refractory to permit the windbox to be readily cleaned via a 6-in. screw conveyor. The combustion chamber is similarly lined with refractory shapes. On the 6-in. diam section, 4 in. of insulating brick, HW-26, are used. The inner combustion chamber is lined with 4-in. Korundal brick to withstand the high flame temperatures encountered. An 8-in. steel feed pipe, entering vertically through the top and fitted with an air-operated cone valve,

Jan 1, 1953

By F. S. White, E. L. Kinsella

Solids fluidization utilized in two ways for the commercial production of lime is described. Crushed —6 mesh limestone is dried and dedusted in a single bed reactor, then calcined in a 5-stage reactor. Construction, operation, and results obtained with both processes are given. THE solids fluidization process brought out by the Standard Oil Development Co. in the early forties for catalytic cracking of petroleum enabled rapid transfer of large quantities of heat from gases to solids under closely controlled temperature conditions. As the technique developed, it was natural that applications for the process outside the petroleum industry would be sought. The calcination of limestone to quicklime requires the transfer of a large quantity of heat at high and closely controlled temperatures. For these reasons, this possible application was one of the first to be investigated. Laboratory work conducted by the Dorr Co. indicated that lime produced by solids fluidization would be of exceptional quality. Calculation of theoretical heat balances showed that savings in fuel could be expected. Accordingly, a pilot plant of 10 tons per day capacity was erected by the New England Lime Co. at Adams, Mass., to substantiate the process. Operation of the pilot plant, previously described,&apos; showed that excellent lime could be produced with a saving in fuel. The work also indicated the necessity of preparing feed to remove the finer fractions if dust losses were to be held to a tolerable level. A single-stage fluidized solids drier-stripper was developed to accomplish this sizing.&apos; Subsequently a commercial lime reactor was erected at Adams, beginning operation in June 1949, followed by air sizer facilities completed in November 1951. This paper will describe these two applications of solids fluidization. The raw material for preparation of lime by the fluidizing process is a high calcium crystalline lime- stone having the approximate chemical composition shown in Table I. The stone is first prepared by crushing and grinding in conventional equipment to pass a 6-mesh sieve. After crushing, the material is sent to the FluoDry unit for drying and dedusting. Fluidized Drying and Sizing As shown in Fig. 1, the FluoDry unit consists of a -in. cylindrical steel shell, 9-ft ID by 22-ft 6-in. overall height. Attached horizontallv at the bottom is a 6-ft diam combustion chamber, approximately 7 ft 6 in. long. A refractory constriction dome, consisting of first-quality fire brick shapes, partitions the inside into two sections. The lower section is called the windbox and the upper the bed compartment. The vertical wall of the shell is lined with 6-in. first-quality rotary kiln blocks. In the bottom of the windbox a hoppered section is formed with castable refractory to permit the windbox to be readily cleaned via a 6-in. screw conveyor. The combustion chamber is similarly lined with refractory shapes. On the 6-in. diam section, 4 in. of insulating brick, HW-26, are used. The inner combustion chamber is lined with 4-in. Korundal brick to withstand the high flame temperatures encountered. An 8-in. steel feed pipe, entering vertically through the top and fitted with an air-operated cone valve,

Jan 1, 1953

By Charles Will Wright

ALTHOUGH the United States has long led all other countries in both the production and consumption of mineral products, the trend seems definitely toward an increasing dependence upon foreign sources of supply. This is not to take the position that we are either a have or a have-not nation. For years we shall continue to secure a large proportion of our needed minerals: from our own mines, but we must face the fact that this century has seen "a more thorough and intense development of the mineral resources of the United States and a greater depletion of its irreplaceable mineral reserves than has occurred in most other countries. An audit of our mineral production given in the attached charts discloses the extent of our deficiencies. Because of these facts, low-cost foreign sources offer a promising field for the investment of a portion of our mining capital and an opportunity to obtain for the United States a greater supply of strategic metals and minerals. How. ever, to reach this end, the industrialist investing in the foreign field must have the full co-operation and strong backing of the Federal Government and the involved Federal agencies.

Jan 1, 1947

By John T. Galey

Production of crude oil for 1940 in southwestern Pennsylvania was off nearly 70,000 bbl., largely as a result of the great number oi abandonments, together with the lack of extension of the Washington and Green County pools. Oil wells completed numbered 51, which is 26 more than last year, but the total initial production of 259 bbl. is only 18 bbl. greater than in 1939. There was an increase of 72 over last year for a total of 209f gas wells. However, 68 7 dry holes were drilled, which is 40 more than a year ago. Thus, 328f wells were drilled during the year, and rigs are erected or drilling is progressing on 59 t more. Shallow Development Oil.—Butler County led in number of oil wells completed, with a total of 27 for an initial production of only 69 bbl. Washington County, with 12 new oil wells, one of which made 40 bbl. from the Fifth sand in S. Franklin township, has 95 bbl., while in Allegheny County 9 wells gave an initial of 86 bbl. for the highest Per well average in the area. This initial was given a considerable boost by one 35-bbl and another 2;-bbl. well in West Deer township, where the Fourth sand produced at 1840 feet. Greene County had only one oil well completed during 1940, and Washington County had 12. The subnormal totals for these counties may be explained by the higher cost of completions and the declining price of crude. The first price change in crude during the year occurred on May 22, when a 25 cut was made. A second 25 cut was made July 12, and was followed by a 156 cut on .Aug. 28. This price held until Nov. 12, when there was a restoration of 156. On Dec. 17 a second 156 increase was put into effect, bringing the price to $I.So per barrel. Gas The large increase in the number of gas wells completed may be attributed to three factors; namely, the recently discovered production possibilities of moderately deep, hitherto little tested horizons, together with increased demand and price. The latter has been made possible by a recent decision of the court, which ruled restraining the public service Commision&apos;s prohibition of a raise in the minimum monthly charge to small consumers by one of the major gas companies. A portion of the revenue derived in this manner is being passed along to the producer in the form of higher prices in the field. This higher field rate will remain in effect until a new ruling is made, when it will be reduced in proportion to the reduction of the monthly minimum charge. In an effort to extend the chambers Dam Fifth sand oil pool southwest from Amwell township, Washington County, several wells have been drilled. One of these, in Morris township, washington County, had an initial of 3.2 million cu. ft. open flow from the Big Injun sand. This indicates an entirely new productive area for the latter horizon. Allegheny County had one spectacular well in South Fayette township-—at a depth of about 2500 ft. a 4-million-CU. ft.

Jan 1, 1941

By John T. Galey

Production of crude oil for 1940 in southwestern Pennsylvania was off nearly 70,000 bbl., largely as a result of the great number oi abandonments, together with the lack of extension of the Washington and Green County pools. Oil wells completed numbered 51, which is 26 more than last year, but the total initial production of 259 bbl. is only 18 bbl. greater than in 1939. There was an increase of 72 over last year for a total of 209f gas wells. However, 68 7 dry holes were drilled, which is 40 more than a year ago. Thus, 328f wells were drilled during the year, and rigs are erected or drilling is progressing on 59 t more. Shallow Development Oil.—Butler County led in number of oil wells completed, with a total of 27 for an initial production of only 69 bbl. Washington County, with 12 new oil wells, one of which made 40 bbl. from the Fifth sand in S. Franklin township, has 95 bbl., while in Allegheny County 9 wells gave an initial of 86 bbl. for the highest Per well average in the area. This initial was given a considerable boost by one 35-bbl and another 2;-bbl. well in West Deer township, where the Fourth sand produced at 1840 feet. Greene County had only one oil well completed during 1940, and Washington County had 12. The subnormal totals for these counties may be explained by the higher cost of completions and the declining price of crude. The first price change in crude during the year occurred on May 22, when a 25 cut was made. A second 25 cut was made July 12, and was followed by a 156 cut on .Aug. 28. This price held until Nov. 12, when there was a restoration of 156. On Dec. 17 a second 156 increase was put into effect, bringing the price to $I.So per barrel. Gas The large increase in the number of gas wells completed may be attributed to three factors; namely, the recently discovered production possibilities of moderately deep, hitherto little tested horizons, together with increased demand and price. The latter has been made possible by a recent decision of the court, which ruled restraining the public service Commision&apos;s prohibition of a raise in the minimum monthly charge to small consumers by one of the major gas companies. A portion of the revenue derived in this manner is being passed along to the producer in the form of higher prices in the field. This higher field rate will remain in effect until a new ruling is made, when it will be reduced in proportion to the reduction of the monthly minimum charge. In an effort to extend the chambers Dam Fifth sand oil pool southwest from Amwell township, Washington County, several wells have been drilled. One of these, in Morris township, washington County, had an initial of 3.2 million cu. ft. open flow from the Big Injun sand. This indicates an entirely new productive area for the latter horizon. Allegheny County had one spectacular well in South Fayette township-—at a depth of about 2500 ft. a 4-million-CU. ft.

Jan 1, 1941

By R. Kossowsky

Structural changes in Be-Cu, Be-Ni. Be - Ag, and Be-Fc alloys pressurized in a solid medium were invesligated by resistivity measurements , X-ray diffrac lion in situ and metallogvaphic examination. Some limited tests in liquid medium were also conducted. Good correlation was oblained between diauges of slope of relative resistance us pressure and changes in diffraction pattern. Metallographic examination rez:ealed that the copper, silver, and nickel alloys lwiu heauily due to the applicalion of pressure at room temperature. Using polarized light technique {1012}, {1011}, and possible {1010} twinning planes were identified. At eleuated temperature twinning was moslly confined to the {1012} planes. Although twin-ning could be promoted by application of hydroslutic pvessure (liquid medium), it was strongly enhanced by the pvesence of a nonhydvostatic shear component due to pressurizalion in a solid medium. It was further obserced that a decrease in grain size inlnibiled twinnitzg activily. A great deal of effort has been expended in recent years to render beryllium useful for structural applications. Efforts were concentrated towards a possible phase change and to promoting other than basal deformation modes. Quenching experiments to obtain the high-temperature bcc phase have failed,&apos; nor were alloying additions successful in improving ductility of the brittle hcp phase.2 Herman et a1.3 have reported a new {1011} twinning mode in a Be-4.4 wt pct Cu alloy oriented for a C axis compression sustaining loads to 440,000 psi. A new approach using high-pressure techniques was undertaken at Curtiss-Wright, Wright Aeronautical Division Laboratories. Marder4 reported a 25 pct decrease in relative resistance of commercially pure beryllium at 92 kbar. He proposed that this discontinuity corresponded to the bcc phase found at high temperature; however, X-ray diffraction in silu did not confirm a phase transition.5 contre6 has recently shown that the bcc transition in pure beryllium is lowered to 800°C at 80 kbar accompanied by a 50 pct increase in relative resistance. The purpose of this paper is to report on one phase of an investigation of the effects of high pressures and temperatures in beryllium alloys, namely, twinning behavior in Be-Ni, Be-Cu, Be-Fe, and Be-Ag alloys pressurized to nearly 100 kbar and temperatures up to 200°C. EXPERIMENTAL METHODS Material was obtained from Nuclear Metals, Inc., in the form of a 1.5-mm-diam wire extruded in stainless-steel cladding at 1600° F. Nominal composition of the alloys is listed in Table I, and the major impurities are are given in Table 11. Pressures to 100 kbar* were ob- tained using a National Bureau of Standards type 100/400 ton tetrahedral unit supplied by Barogenics, Inc. This type of apparatus contains a retaining sleeve with a conically tapered internal surface and four pressure-intensifying anvil assemblies with tungsten carbide tips. The 10-mm-long specimen fits into a pyro-

Jan 1, 1968

By R. D. Carnahan, J. E. White

A study of dispersion strengthening in TD-Nickel (nickel plus 2 vol pct Tho2) was conducted employing microstrain techniques at ambient room temperature. It was found that optimum strength was due primarily to the incorporation of stored energy developed by a variety of thermal-mechanical treatments. The relatively low strength of the recrys-tallized condition implies that the dispersed particles themselves offer only token resistance to deformation. The development of resistance to large-scale recovery or recrystallization at temperatures near the melting point requires a more extensive sequence of strain-anneal cycles than does the development of optimum strength. A micro-Bauschinger effect was observed which appears to be related to the lattice resistance to the movement of free dislocations. The effect was nearly identical to that in pure nickel indicating that the presence of the dispersed phase and considerably increased dislocation density (stored energy) only alters the number or effectiveness of barriers. THE early stages of deformation of engineering materials can be conveniently studied by utilizing strain-gage techniques which permit resolution of strains less than 5 X 10-7 in. per in. for testing in four-point bending (Carnahan and white1). The present investigation, part of a continuing study on the very early stages of deformation, was designed to reveal the true role of a dispersed phase in promoting high strength in a commercially available dispersion-strengthened alloy. Although this technique has been used for some time to study microdeformation in pure metals and alloys, it has just recently received attention as a means of investigating dispersion strengthening. Studying the very early stages of deformation in alloys which depend upon a finely dispersed inert phase for strength may prove to be a very important method for a better understanding of these materials. It is essential to obtain considerable clarification of actual dislocation movement and the kinds of deformation barriers which exist before optimum properties can be designed into this type of material with any degree of confidence. Considerable research on a variety of dispersion-strengthened materials has resulted in two different schools of thought regarding the strengthening mechanism. One faction2-4 favors the idea that the particles themselves resist the motion of dislocations. The criterion for yielding is the fracture of the dispersed second-phase particles due to an array of piled-up dislocations. Other invesfigators5-a have shown that particles are effective primarily by allowing a greater buildup of stored energy or dislocation density through thermal-mechanical treatments in the composite than the pure matrix material. The particles themselves, then, are not exclusive obstacles, but the complex network of particles, dislocation tangles, subboundaries, and grain boundaries are strength determining. The development of such a complex dislocation network in SAP has been studied recently in some detail by Goodrich and Ansell. The ability of dispersion-strengthened alloys to resist softening or recrystallization is also of considerable importance; however, the criteria for maximum stability may not necessarily be those for maximum strength. In this study, in addition to the evaluation of the microstrain properties of TD-Nickel, it is felt that considerable clarification of the true dependence of strength and stability on the dispersed phase is shown. I) MATERIAL AND PROCEDURE TD-Nickel is a dispersion-strengthened alloy developed by the E. I. DuPont de Nemours Co., which contains 2 vol pct thoria (Tho2) in a pure-nickel matrix. The average ThO2 particle size is approximately 0.1 p and the interparticle spacing is less than 1 u. The material was supplied by DuPont in two conditions: hot-extruded bar stock, and stress-relieved cold-rolled sheet 0.025 in. in thickness. The bar was extruded at 2200°F from a cold-pressed and sintered billet. The sheet stock was prepared from the extruded material by a process involving ten or more 50-pct cold reductions by rolling with intermediate anneals at 1800° to 2000°F. Test specimens used in this study were prepared in the form of rectangular parallelepipeds measuring 0.375 by 1.375 in. in thicknesses ranging from 0.025 to 0.040 in. Samples prepared from sheet and extruded stock were mechanically polished before heat treatment and were handled with extreme

Jan 1, 1964

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&apos; 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

By Oscar H. Hershey

COMPLAINT has been made that in the literature of economic geology the work of the "company or practical" mining geologists does not get enough attention. I propose to attempt to overcome this com¬plaint in reference to one important lead-mining district, that of the Coeur d&apos;Alene in northern Idaho. Furthermore, I will assume that the reader is not so much interested in the geology of the district as in the methods of application used and incidents that have arisen in the work. All the important discoveries of ore in the Coeur d&apos;Alene were made without benefit of geology. Certainly I would not claim the reputed discoverer of the Bunker Hill mine as a fellow geologist. It appears also that the mines were operated quite successfully for many years without geological specialists, though doubtless certain properties were visited at long intervals by such men as Waldemar Lindgren. It was known that the ores occur in quartzite, graywackes and slates as stated by J. R. Finlay in 1903. (TRANS., VOL. 33.) He described the ore as occurring in typical fissure veins that occupy fault-planes of indeterminate displacement. The Bunker Hill lode was based on a definite fissure with the mineralization all on the hanging-wall side, extending as far as 300 ft. from the fissure.

Jan 1, 1933