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By HAROLD A. KNIGHT

The Miami Copper Co., Arizona, is asking Congress to reimpose the import duty of two cents per pound on copper which, by law, has been suspended until June 30, 1950. C. Donald Dallas, chairman of Revere Copper and Brass, champion of a duty-free regime as regards the red metal, has been answering E. H. Westlake, Miami president, now that Mr. Westlake's statement to stock- holders has been salted away for posterity on wire recorders. Even prior to this action and at the instigation of two prominent consumers of pig lead, the House of Representatives has, in the confines of committee, not yet reported out, as of June 16, a bill to suspend the duty on lead for another year from expiration of the present law June 30, 1949. But apparently the bill was started too late. Thus the tariff issue becomes a Rip Van Winkle again after having slept for several years in the mountains of metals scarcity. During the wartime scarcity and the boom days that followed, most metal producers welcomed a considerable influx of foreign metal since it gave them a little surcease from constant teleibhone calls asking why that delivery of 300 tons of lead, 250 tons of zinc, and 1000 tons of copper had been delayed. These were the days when it was such an undisputed sellers' market that the sellers had even thrown away their certificates of ownership. Another development that brings home the tariff situation, small in it- self but perhaps indicating a trend, has been the announced closing of

Jan 1, 1949

By M. M. Fine

Normally the U. S. produces less than 10 pct of its annual manganese requirement. About 95 pct of domestic consumption is used by the steel industry.1 The strategic and critical nature of manganese has been recognized by its inclusion in the national stockpile and by intensified research directed toward cataloging and evaluating domestic manganiferous deposits. The USBM has participated in these activities for many years with field and laboratory studies to assess the extent and potential utilization of domestic manganese ores. One area of particular interest is in the vinicity of Batesville, Ark., where deposits have been mined since 1849 for both manganese and ferruginous manganese ores. Production is centered in Independence County, but deposits are also found in Sharp, Izard, and Stone counties in north- central Arkansas. Miser has described the geology and manganese mineralization in some detail.2,3 The rocks of the area are sedimentary, consisting of sandstone, limestone, shale, and chert. The two formations of greatest importance,4 Fernvale lime- stone and Cason shale, are host rocks of the primary manganese mineralization.

Jan 8, 1959

By David B. Reger

The substantial expansion of previously discovered gas pools was the principal feature of petroleum activity in West Virginia during 1940. At least one new gas pool was discovered and various other successful wildcat completions may prove to be gas-pool openers. Some slight extensions of oil pools were also made. The new productive territory, principally gas, added by these extensions was approximately 33,800 acres. ' In general, oil activity was slight because of unfavorable crude prices. Gas activity, on the contrary, increased considerably, although the price of gas did not materially change. The account of operations, as gathered from trade journals and other reporting services, shows that 709 new wells were drilled, resulting in 102 new oil wells with I055 bbl. of daily new produc-tion; 468 new gas wells with 633>g47,000 cu. it. of daily open flow; and 139 dry holes. Also, 91 old wells were drilled to deeper sands, with 143 bbl. and 44,833,000 cu. ft. of added production. On the new wells the oil average was 10.34 bbl, per well per day; and the gas average was 1,354,000 cu. ft. per well per day. On new wells the ratio of dry holes to completions was 19.61 per cent. On deeper drilling to other sands the ratio of failures was 12.I per cent. From an exploratory standpoint, one strictly new gas pool (Lorentz) was opened in Upshur County. Little forecast of its extent or reserve can now be made. The new extensions of various other previously discovered pools, however, give assurance of a new gas reserve that will equal approximately a year of gas demand. In addition to these definite supplies two widely separated Oriskany sand (L. Dev.) wildcats in Jackson County, one of which was completed late in 1940 and the other early in 194.1, may indicate two separate pools or may greatly extend known pools. In south-ern Kanawha County, also, an old Oris-kany-sand well deepened to the White Clinton sand (Sil.) showed a volume of 733,000 cu. ft. and rock pressure of 1800 Ib., giving rather clear assurance that this deep sand, in which only slight quantities of gas had previously been found, should eventually supply much new gas. On the other hand, various deep tests to the Oriskany sand in Harrison, Putnam, Randolph and Wood Counties were totally dry or gave only small volumes of gas, The principal oil wells completed, by counties, were: Calhoun, 15; Clay, Ir; Pleasants, 14; Ritchie, 15; and Roane, 7. Production for the year was estimated by the U. S. Bureau of Mines as 3,444,000 bbl., as compared to 3,684,000 bbl. in 1939. The leading counties in gas-well completions were: Boone, 36; Braxton, 17; Cabell, 25; Calhoun, 16; Clay, 22; Gilm.er, 47; Jackson, 38; Kanatvha, 77; Lincoln, 18; Putnam, 32; IGtchie, 40; and Wayne, 31, Production for the year is estimated by me as I70,000,000,000 cu. ft. as compared to I59,226,000,000 cu. ft.* in 1939. No long pipe lines were built but various gas-line extensions and cross connections,

Jan 1, 1941

By David B. Reger

The substantial expansion of previously discovered gas pools was the principal feature of petroleum activity in West Virginia during 1940. At least one new gas pool was discovered and various other successful wildcat completions may prove to be gas-pool openers. Some slight extensions of oil pools were also made. The new productive territory, principally gas, added by these extensions was approximately 33,800 acres. ' In general, oil activity was slight because of unfavorable crude prices. Gas activity, on the contrary, increased considerably, although the price of gas did not materially change. The account of operations, as gathered from trade journals and other reporting services, shows that 709 new wells were drilled, resulting in 102 new oil wells with I055 bbl. of daily new produc-tion; 468 new gas wells with 633>g47,000 cu. it. of daily open flow; and 139 dry holes. Also, 91 old wells were drilled to deeper sands, with 143 bbl. and 44,833,000 cu. ft. of added production. On the new wells the oil average was 10.34 bbl, per well per day; and the gas average was 1,354,000 cu. ft. per well per day. On new wells the ratio of dry holes to completions was 19.61 per cent. On deeper drilling to other sands the ratio of failures was 12.I per cent. From an exploratory standpoint, one strictly new gas pool (Lorentz) was opened in Upshur County. Little forecast of its extent or reserve can now be made. The new extensions of various other previously discovered pools, however, give assurance of a new gas reserve that will equal approximately a year of gas demand. In addition to these definite supplies two widely separated Oriskany sand (L. Dev.) wildcats in Jackson County, one of which was completed late in 1940 and the other early in 194.1, may indicate two separate pools or may greatly extend known pools. In south-ern Kanawha County, also, an old Oris-kany-sand well deepened to the White Clinton sand (Sil.) showed a volume of 733,000 cu. ft. and rock pressure of 1800 Ib., giving rather clear assurance that this deep sand, in which only slight quantities of gas had previously been found, should eventually supply much new gas. On the other hand, various deep tests to the Oriskany sand in Harrison, Putnam, Randolph and Wood Counties were totally dry or gave only small volumes of gas, The principal oil wells completed, by counties, were: Calhoun, 15; Clay, Ir; Pleasants, 14; Ritchie, 15; and Roane, 7. Production for the year was estimated by the U. S. Bureau of Mines as 3,444,000 bbl., as compared to 3,684,000 bbl. in 1939. The leading counties in gas-well completions were: Boone, 36; Braxton, 17; Cabell, 25; Calhoun, 16; Clay, 22; Gilm.er, 47; Jackson, 38; Kanatvha, 77; Lincoln, 18; Putnam, 32; IGtchie, 40; and Wayne, 31, Production for the year is estimated by me as I70,000,000,000 cu. ft. as compared to I59,226,000,000 cu. ft.* in 1939. No long pipe lines were built but various gas-line extensions and cross connections,

Jan 1, 1941

By AIME AIME

REGISTRATION and licensing of engineers is now being given consideration by a special committee of the Institute, authorized at the March meeting of the Board of Directors. The subject is one that has recently been or is now actively before engineering organizations in many of the States of the Union. In Washington, D. C., the Washington Society of Engineers and the local sections of ten national engineering societies, including the A.I.M.E., recently had a joint committee investigate the subject: this committee formulating a proposed law that has been presented to Washington engineers for their consideration. At the same time, the committee has summarized the reasons for and against registration of engineers in Washington, D. C. As many of these reasons are of more than local application, they are here reprinted so that all members of the A.I.M.E. may be informed on the subject. It is expected that some report of the Institute's Committee on Registration, State Councils and Professional Development will he made at some forthcoming meeting of the Board of Directors.

Jan 1, 1932

By M. E. Nicholson

IN order to understand how alloying elements influence hardenability through their effect on the rate of pearlite nucleation, it is advantageous to use a model to describe the mechanism of pearlite nucleation. The model which currently is most widely accepted has been described, among others, by Mehl et a1.1-3 and by Hultgren.4 Pearlite nucleation involves both the nucleation of ferrite and cementite.4,5 Cementite nucleates first, followed rapidly by the formation of ferrite at the cementite-austenite interface. The conclusion that cementite is the first phase to form during the process of pearlite nucleation is based, in part, on the observation that proeutectoid cementite is continuous with pearlitic cementite and that the orientation relationship between proeutectoid ferrite and austenite is not the same as that between pearlitic: ferrite and austenite.6,7 Recently, Smith" has suggested that the dissimilarity in orientation relations, instead of indicating the pearlite nucleation sequence, may be evidence that pearlite is nucleated in a grain adjacent to the one in which it is growing. Also, Modin9 as shown that ferrite in pearlite may be continuous with proeutectoid ferrite, and he has also shown that proeutectoid cementite is not always continuous with pearlitic cementite. Thus, it appears that the conclusion that cementite always initiates the pearlite nucleation process is open to serious question. The author believes that important evidence on the question of how pearlite is nucleated exists in the rates of pearlite nucleation of different steels. The following is a review and analysis of this evidence. If the nucleation of pearlite is considered as requiring the nucleation of both cementite and ferrite, then the time to nucleate pearlite consists of the time to nucleate the first phase to form, plus the time to nucleate the second phase at the advancing interface of the first. In the absence of a visible proeutectoid constituent, the second phase must be nucleated very soon after the first. If cementite is the first phase to form, the time to nucleate pearlite will be approximately equal to the time to nucleate cementite. Since the nucleation rate of a phase precipitating from solid solution increases with the degree of supersaturation, it would be expected that the rate of pearlite nucleation should increase with increasing carbon content. Digges10 has shown that the reverse is true. He determined the quenching velocity necessary to suppress pearlite formation in plain carbon steels as a function of carbon content. His results showed that pearlite formation could be suppressed with lower quenching velocities as the carbon content of the steel increased, at least up to 1.25 pct C, the highest carbon content he studied. Thus, it would appear that in plain carbon steels, in which pearlite is formed at the nose of the C-curve, the hypothesis that cementite nucleates first does not predict the observed change in nucleation rate. The validity of the current model of pearlite nucleation may be tested also by determining whether or not it predicts the relative influence of alloying elements on the nucleation of ferrite and pearlite. This can be done best by a consideration of the changes in a TTT diagram produced by a change in alloy content. Hultgren4 suggests that the general shape of a TTT diagram, as well as what constituents will form from austenite, can be predicted from the relative nucleation rates of ferrite and cementite. This is illustrated in the schematic diagram for a hypoeutectoid low alloy or plain carbon steel shown in Fig. 1. The C-curves for ferrite nucleation and for cementite nucleation are represented by AA' and CC', respectively, and the start of ferrite formation and pearlite formation are represented by AX and BC respectively. Adopting the current theory, Hultgren suggests that between X and C pearlite forms directly from austenite, since cementite nucleates more rapidly than ferrite in this temperature range. Conversely, at temperatures above Tx, ferrite is the first to nucleate and proeutectoid ferrite is formed. As proeutectoid ferrite grows, austenite becomes enriched in carbon, so that the cementite nucleation rate is increased. As a result, pearlite nucleation above temperature Tx is accelerated, beginning along BX and not along C'X. Temperature T, represents the temperature at which the nucleation rate of ferrite equals that of cementite. By extending this type of reasoning, using the principle that the nucleation rates of ferrite and cementite increase with increasing supersaturation of austenite with respect to these phases, it should be possible to predict the influence of carbon content on the shape of the isothermal transformation diagram. For a slightly higher carbon content than that of Fig. 1, the curve A A' representing the beginning of ferrite formation should be moved to the right, whereas the curve CC' representing the beginning of cementite formation should be moved to the left. For hypoeutectoid plain carbon and low alloy steels, this prediction does not agree with existing data. Instead, as the carbon content is increased, the pearlite curve moves to the right along with the ferrite curve and always appears to join it tangen-tially. This behavior is demonstrated by the TTT-curves of a series of manganese steels" shown in Fig. 2. In this figure, TTT-curves for four alloys containing 0.20, 0.40, 0.60, and 1.20 pct C are superimposed. The curves are identified in the figure legend. The letters F, P, and C are used to indicate the start of ferrite, pearlite, and cementite formation, respectively. In these steels, it appears that the nucleation of ferrite and of pearlite are related processes. As a result of the foregoing evidence, it is proposed that the formation of pearlite be considered as follows: Either ferrite or cementite may nucleate from austenite, then grow until the remaining phase is nucleated at the interface between the growing phase and austenite. (The growth of the first phase to form is assumed to be accompanied by a composition change in the adjoining austenite.) According to this model there are two modes of nucleating pearlite: 1—where cementite initiates the succession

Jan 1, 1955

By W. L. Phillips

Aluminum and copper single crystals were strained in shear, unloaded and rotated 60, 120, and 180 deg. The magnitude of the Bauschinger strain increased rapidly during the easy glide region and became constant as the easy glide limit was reached. An increment in stress was not required to continue slip in any close-packed plane or in the reverse direction during easy glide. A qualitative theory is proposed to explain the present results. FOLLOWING the initial work on tin by Bausch,' there have been several investigatorsB7 who have employed the shear test to study the deformation of aluminum. In all cases the shear technique was employed in an attempt to obtain a more homogeneous shear than in the conventional tension test The direct shear technique has the obvious advantage, relative to the tension test, that a crystal may be stressed in any predetermined plane and direction, including the reversal of strain sense. In the present investigation the shear technique was employed with aluminum and copper single crystals and their behavior was studied with respect to deformation in all close-packed directions in the octahedral plane. In contrast to previous investigations, the shear technique was used in an attempt to obtain a stress-strain curve in shear which is identical with the corresponding tension curve and then to use the additional degree of freedom of the shear test to study the mechanical behavior of crystals in all close-packed directions in the octahedral plane. PREPARATION OF CRYSTALS Single crystals 1/2 in. in diam and 6 to 7 in. long, were prepared from aluminum containing 0.001 pct Si, 0.001 pct Fe, and 0.001 pct Zn, by spectro-graphic ana1ysis and from OFHC copper. Crystals were grown from the melt in graphite at a rate of 1 5 in. per hr. The copper crystals were grown under an argon atmosphere. No lineage structure was observed in Laue patterns, though small angle boundaries were present in the crystals. The aluminum and copper crystals were annealed at 640" and 900°C, respectively, for 24 hr and furnace-

Jan 1, 1962

By C. E. Morris, S. R. Pollack

Current -vo1tage -temperature characteristics were studied for Al-A12O3-Al, Au structures. The oxide film was grown by gaseous oxidation in an 0, glow discharge. The electron-transfer mechanism was identified as tunneling and the barrier heights and thickness were determined. It was found that the barrier height at the parent aluminum-oxide interface is 1.5 ev and the built-in vloltage with an aluminum counter electrode is 0.35 v. The growth mechanism of the oxide is also discussed and it is suggested that Mott&apos;s theory is not applicable in describing the growth. Discrepancies were observed in the detailed comparison of tunneling theory, based on a trapezoidal model, with the data, and several possible explanations are discussed. THEORETICAL analyses of electron tunneling from one nonsuperconducting metal to another through an extremely thin insulating film have been presented.1-6 These calculations relate the current density, J, to the voltage, V, between the two metals, and to the temperature, T. The results of these calculations indicate that the magnitude of J and the detailed shape of the J-V characteristic will in general depend most strongly upon such properties of the insulating film as the thickness, the dielectric constant, and the structure of the electron energy barrier profile. The experimental results of many7-11 workers have corroborated the main features of these calcu- lations and have in fact been used to determine properties of the thin insulating film. It has been demonstrated, for example, that the tunneling current formulation of simmons4 is adequate to describe the observed J-V characteristic over approximately 10 orders of magnitude of current. Furthermore, from these observations and analyses, insight into the nature of the A1-A12O3 (thermally grown) interface region has been obtained.&apos;&apos; The temperature dependence of the tunnel current has also been studied and, although a self-consistent set of tunneling parameters can be chosen to describe these data at low voltages (i.e., <0.5 v), the tunneling parameters are different from those obtained from higher voltage (i.e., of the order of 1 to 5 v) measurements." We have measured the effect of temperature and voltage upon the tunnel current at higher applied voltages and find that the theory is inadequate to describe all of the effects reported here. A discussion of the origin of this inadequacy is presented following a description of the samples used for these experiments, and the experimental results. SAMPLE PREPARATION Metal-insulator-metal structures were fabricated in the following way. A 99.999 pct A1 charge was used to deposit, in vacuo, thirty films, 2000Å thick, onto a 1 by 2 in. glass substrate (7059 Corning glass). Prior to deposition the substrate was glow-discharged for final cleanup and then baked at 200°C for 2 hr at a pressure of 5 x 10-7 torr. The pressure during deposition of the metal films was 2 X 10-6 torr and the deposition rate was 50 to 100Å per

Jan 1, 1965

By Charles R. Fettke

The permeability of an oil or gas sand is its capacity for transmitting fluids, either liquids or gases, under pressure. The permeability of a sand depends upon the size and shape of the openings in it and the extent to which these communicate with one another, as well as upon the ratio of their volume to the total volume of the sand. The apparatus employed and the method of procedure used by the authors in conducting the permeability tests have been described in a previous pub1ication.l For the tests described here 1/2-in. cubes were used. They were set in the lower end of a 1-in. union, inserted in a square hole cut in a hard rubber stopper which fitted into the lower end of the union. In the tests with air, volumes were measured with a wet American gas meter of 100 cu. ft. capacity. In those with water, distilled water at room temperature was employed, unless otherwise noted. DescRiption of Sands Tested The tests described in this paper were performed upon 18 samples representing typical oil and gas sands from 7 localities in northwestern Pennsylvania. For purposes of identification, the cores from which the samples came have been designated by capital letters, the sequence of the samples in the cores by numerals, and the individual cubes by small letters. All cubes from the same samples came from adjacent portions parallel to the bedding. Core A of the Bradford sand came from the north central part of the Bradford field, from an area where water-flooding operations have proved highly successful. Core B of the same sand was obtained from the southern part of the field. This core contained a so-called "loose streak," 7.5 ft. thick, in the middle portion of which B2 is a representative sample. The "loose streak" has given trouble in water-flooding but responded favorably to an air-drive, using a pressure of 300 lb. The natural production was increased approximately five times over a period of three years in which the air-drive was in operation. Core C, also of the Brad-

Jan 1, 1931

By N. F. Fiore, M. F. McGuire

THIS communication describes a series of experiments in which dislocation etch pitting was used to ascertain the depth of damage in crystals which were mechanically polished or which were cut with either a commercial metallographic cut-off wheel,* a com- All specimens were cut from single crystals of American Smelting and Refining Co. 99.999+ pct pure copper which were grown from the melt by the Bridge-man technique. The test specimens were disks, with faces being (111) planes and the disk axis a (111) direction. The disks were annealed in a vacuum of 10-5 Torr for 24 hr at 950°C prior to cutting or polishing and were given a light electropolishing in an ortho-phosphoric acid bath before etch pitting. Both Youngs1 and Livingston&apos;s2 reagents were used for etch pitting and the reagents gave identical quantitative results; however Livingston&apos;s reagent produced less staining and so all photomicrographs shown are of {111) surfaces etched with this solution. The surface of the annealed crystals showed well-defined subboundaries and a density of dislocations of about 1 X 106 per sq cm excluding those present in subboundaries, Fig. 1. The depth of cold work produced during mechanical polishing was determined after an annealed specimen was mounted in a paraffin holding block to protect it from extraneous damage. The exposed (111) surface was ground on metallographic papers and then polished on billiard cloth through 0.05-p alumina abrasive. It was necessary to remove about 0.3 mm (-0.01 in.) to obtain a structure representative of the annealed sur- face, indicating that the crystal was damaged to this depth during mechanical polishing. The cold work caused by standard cutting methods was measured in another series of tests in which cuts

Jan 1, 1967

By F. B. JEWETT

TWENTY FIVE years of doing, finding, and encouraging others to do scientific research in&apos; industry, and of organizing the machinery for the` smooth &apos;and effective conduct of such research, have left me with a feeling that so far as this branch of human activity is concerned the problems in &apos;essence are- not, materially &apos;different from those met elsewhere. Years ago, in a less mature period of life, I may have thought that the effective industrial research man was a being somewhat different from his fellow workers in adjacent &apos;fields, but I have long since &apos;changed my views. The rank and&apos; file of the modern industrial research organization are relatively easy to find, though some¬times difficult to get in sufficient numbers. Mistakes in choosing them are not particularly serious to the or¬ganization, however unfortunate they may be for the misplaced individual who persists too long in the wrong environment. The reason for this is obvious from the fact that, taken by and large, the work of the rank and file is at best necessarily a work of detail done under guidance of the more experienced. In this respect the situation of the rank and file in an industrial research organization is not different from that class in any other group activity, whether concerned with industry, the university, or the church. This does not mean, however, that we are not all anxious to have the best possible material obtainable in the rank and file, or that we are indifferent to the utmost of encouragement and stimulation to its individual members.

Jan 1, 1929

By A. Kaufmann, B. Cullity, G. Bitsianes

T0 determine the bulk of the phase diagram, techniques for melting, thermal analysis, heat treatment, metallography, and X-ray diffraction that have already been described were used.&apos; It proved difficult to get definitive results for most of the alloy system because of the large number of compounds, their high melting points, and their extreme brittle-ness which made metallography difficult. The final phase diagram, essentially as shown in Fig. 1, was issued with considerable trepidation.&apos; The phase relationships at the two ends of the system were defined with satisfactory accuracy. In the central region between U,Si, and USi, there was great uncertainty concerning the melting points and even the composition of the compounds. At the uranium end of the system, it is quite clear that a eutectic exists at about 985 °C and approximately 8 or 9 atomic pct Si. The a-to-8 transformation is not appreciably altered by silicon, but the 8-to-y transformation is raised to about 795°C. There is appreciable solid solubility in y-uranium, as demonstrated by the micrographs of Fig. 2. The occurrence of the E phase was not suspected at first, since the alloys as melted and furnace cooled gave no X-ray diffraction or thermal arrest indication of it. However, suitable metallography revealed a rim around each of the compound particles as shown in Fig. 3. Heat treatment above 600°C revealed that the rim was another phase which formed by peritectoid reaction between uranium and U,Si,. This reaction proceeds slowly and it is difficult to get it to go to completion. Consequently, there is some uncertainty concerning the exact composition of P and the exact peritectoid temperature. On the basis of various metallurgical studies, it was decided that the most probable composition for t was about 23 atomic pct Si. Metallographic examination shows the closest approach to a single phase at this composition. Likewise, density and hardness measurements of heat-treated alloys shown in Figs. 9 and 10 show a change in slope at 23 pct Si. This is revealed most clearly by plotting the difference in hardness or density between chill-cast and heat- treated alloys as shown in Fig. 4. Zachariasen2 was able to index the diffraction lines of P and to determine the arrangement of the atoms in the unit cell. He concluded that the composition must be US. However, it is felt that the metallurgical studies are reliable and that Zachariasen&apos;s X-ray work does not furnish positive proof that the P phase exists exactly at the stoichiometric composition U3Si. There are many instances in alloy systems where a phase does not occur at the composition dictated by the molecular structure. It is possible that the chemical analyses used in the present work were subject to some systematic error. This seems unlikely, however, since recent work in several laboratories seems to show excess compound at 25 atomic pct Si.

Jan 1, 1958

By F. A. Forward, J. Halpern

A new process is described for extracting uranium from ores containing sulphidic minerals, which comprises treating an aqueous pulp of the ore with air or oxygen at elevated temperatures and pressures. The acid required to dissolve the uranium is generated during the leach through oxidation of the sulphides. The chemistry of the process is discussed and laboratory results are presented to illustrate the operation of the method and the variables which control it. With most ores, leaching at a temperature of 130°C and an oxygen partial pressure of 10 psi provides uranium extractions of 90 to 95 pct in 4 to 6 hr. The acidity and level of dissolved impurities in the leach liquor can be kept fairly low. The method is characterized by a number of advantageous features including low reagent cost, short retention times, and high recoveries. RECENTLY there have been developed several processes for extracting metal values from ores by pressure leaching techniques;&apos; -&apos; an example is the carbonate leaching process for uranium ores which has been studied in this laboratory.&apos; Leaching is carried out under oxygen pressure to ensure oxidation of the uranium to hexavalent compounds which are soluble in carbonate solutions. During the course of investigations relating to this process, it was observed that sulphide minerals, such as pyrite, usually were oxidized under the conditions of the leach treatment resulting in the formation of iron hydroxides and sodium sulphate, i.e. 2 FeS= + 7Vz O2 + 8 Na,CO3 + 7 H,,O -* 2 Fe(OH)3 + 4 Na2SO4 + 8 NaHCO.,. [1]

Jan 1, 1956

By R. L. Mauger, P. E. Damon, B. J. Giletti

This report includes the lead isotopic dating of a suite of galenas from Arizona and an application of the K-Ar method to the dating of a Laramide porphyry copper deposit, the Silver Bell Mining District. The lead isotopic data supports prior age assignments based upon geologic inference. The Silver Bell study illustrates the necessity of correlative geologic and petrographic investigations for the interpretation of the results of potassium-argon dating. LEAD ISOTOPIC DATING OF GALENAS FROM ARIZONA ORE DEPOSITS A group of galenas from Arizona ore deposits have been analyzed for lead isotope ratios. The results were used to calculate model ages by the. method of Russell, Stanton and Farquhar,l6 in which the age is calculated directly from the Pb206/Pb207 ratio. The use of Pb206/Pb207 ratios eliminates the errors inherent in measuring the abundance of Pb204. The Holmes-Houtermanns model is the other model commonly used for calculating model ages. Both models assume that any lead sample is composed of primeval and radiogenic components and the calculated age is the time at which the lead was extracted from its source area. Using the Holmes-Houtermanns model, a lead is ordinary if its isotopic ratios lie on an isochron. The growth curve that passes through the experimental point determines the U/Pb ratio in the source area. The RSF model assumes the source area for conformable leads is the mantle, that this has a uniform U/Pb ratio, and thus all ordinary leads must lie on a single growth curve, having a mantle U/Pb ratio. The definition of an ordinary lead differs between the models, and differences in age arise mainly from the assumptions made to evaluate parameters in the model equations. These assumptions depend on the hypothesis chosen to explain ore genesis. In the RSF Model, the Pb206/Pb207 ratio is derived as a function of time. The equation contains three undetermined parameters which are evaluated by assuming three known points lie on the curve. These are the following: 1) Primeval lead from the Canyon Diablo and Henbury meteorites, 2) Modern conformable leads which lie on Patterson&apos;s zero isochron, 3) Lead from the Bathurst, New Brunswick base metal deposits. The Bathurst deposits are postulated to be examples of "conformable base metal deposits", as proposed by Stanton.l9 A conformable deposit has a particular genetic history and, as a result, the orebody conforms to stratigraphic layering in the host rock. The metals are brought to the surface in volcanic rocks which originated in the mantle. Weathering products of these rocks, including sulfur and metals, accumulate in areas undergoing sedimentation. The formation of sulfide ion in the sediments by the action of sulfate reducing bacteria causes fixation of iron as pyrite. If the pyrite becomes concentrated in favorable stratigraphic horizons, any base metal deposit eventually formed by replacement of pyrite will have a strata bound character. Compaction and expulsion of pore water from the sediments at depth result in upward mobility of solutions containing soluble base metal chlorides. The strata with high pyrite content act as chemical traps for the base metal ions and replacement occurs. An important result of this general evolutionary model is that, if complete separation of lead and parent isotopes occurred during accumulation of the sediments, any ore deposit formed solely of metals derived from those sedimentary rocks will contain "conformable" lead. This would be true even if the actual ore deposit were formed at a later date by some epigenetic process. In this case, mineralization would be controlled by local conditions, and need not conform to stratigraphic layering. Also, any ore deposit containing lead derived from a mantle or mantle-like source, even though not conformable in Stanton&apos;s sense, will fall on the curve for conformable ores and thus give a meaningful model age. Model ages for Arizona galena deposits are listed in Table 1. Fig. 1 is a location map. Jerome-Humbolt District: Galenas from the United Verde mine at Jerome and the Iron King mine at Humbolt give model ages of 1750 m.y. and 1640 m.y. respectively. Both deposits are massive sulfide bodies in a host rock of older Precambrian

Jan 1, 1965

By William Sellers

tested without knowing anything of their chemical composition. I had these pieces separately placed upon 10-inch bearings under a 7-gross ton lianlrner, a piece of 2½-inch round iron laid upon them as a fuller, and the hammer allotved to fall from 20 inches above the fuller, which, according to Haswell, gave a ldow of 67.75 gross tons. The pieces were then turned orcr, the fuller placed upon the convex surface, and the harnnler allowed to fall from 13 inches above the fuller, giving a blow of 58.46 gross tons. You will see that the rails do aot show ally bigrls of ruptnre, and their color at the points of torture prove them to have been absolutely cold when the test was made. I thirk these rails ought to be reasonably safe in the track. As you see by this piece of the head of one of these rails, I had it plarred, and then some teeth cut in it by a cold clrisel, and one-half of them pounded down with a hammer. The teeth of my rack did not break off. The analyses of these rails substquently made are: I. 11. Carbon,... 0.110 0.880 Silicon,..0.050 0.058 Phosphorus ,..0.086 0.082 Manganese,.. 0.042 0 840 In conclusion, I will say that Dr. Dudley&apos;s paper as a contribu tion to our knowledge of steel rails is valuable and interesting, but I protest against his conclusions king reoeived as manufacturing or comtnercial axioms. From its being presented in the form-of a report to the leading railroad of the country from one of its trusted officers, as well as from the tone of the concluding deductions, it is liable to be so received by railroad men. If any railroad com pany desires rails made under either of Dr. Dudley&apos;s formulas, and are willing to pay a price large enough to cover the loss in making them, dl and good; but so long as the rail makers are compelled to gwrrantee the wear of their rails for a given number of years, justice reqnires that. the composition of the steel from which these rails are made should be left to them. WILLIAM SELLERS, PHILADELPHIA: The very interesting paper upon the wear of steel rails that has just been read preseak the record of a series of investigations that are extreniely valuable, and the deduction that bas been drawn from the results noted seems to be unavoidable; the tests, however, to which it is proposed steel rails shall be subjected hereafter, with a view to determine their quality, sllould

Jan 1, 1881

By Walter Crafts, C. M. Offenhauer

IN a previous study&apos; of the carbide phase of chromium steels, it was shown that chromium carbide (Cr7C3) is a more stable carbide than cementite (Fe3C) at tempering temperatures above about 500°C. in quenched steels containing from about r1to 7.5 per cent chromium. Below this temperature the carbide phase was found to consist of cementite in all of the steels examined. In the present investigation it was found that a similar change in the carbide phase takes place in molybdenum and in chromium-molybdenum steels at approximately the same tempering temperatures. The approximate ranges of occurrence of the alloy carbides Cr7C3, Cr4C, and Mo2C have been determined in steels containing up to 5 per cent chromium, 1 per cent molybdenum and 0.60 per cent carbon. The experimental steels were made in small high-frequency furnaces from Armco ingot iron, low-carbon ferrochromium and calcium molybdate and were poured into 2-in. ingots, which were forged to 1-in. round bars. Sections of the bars were heated to the carbide-solution temperature and cooled rapidly to induce austenite transformation at relatively low temperatures. The steels were subject to some segregation, therefore comparatively high temperatures were necessary to dissolve all of the carbides. The microstructure of the quenched specimens was examined to verify the belief that the carbides had been dissolved, and also to determine the nature of the nonmartensitic structure of incompletely hardened steels. Ferrite and pseudomartensite were present in some of the specimens, but all specimens were quenched at such a rate that pearlite was not formed, in order to ensure the formation of the carbides at temperatures lower than about 500°C. It had been found previously&apos; that in chromium steels the chromium carbide could be produced by transformation of austenite in the pearlite range above 500°C., and, in order to start the tempering treatment with the carbide present as cementite, the absence of pearlite was considered to be essential. The specimens were tempered for 64 hr. to permit the formation of the stable carbide. After tempering, the specimens were submitted to microscopic and X-ray examination. The carbides were separated either electrolytically in a 5 per cent HCl electrolyte or with an acidified copper-potassium chloride solution. The crystal structure of the carbide phases was determined by the Debye-Scherrer type of X-ray patterns. The X-ray patterns obtained from specimens near the boundaries between two types of carbides were generally weak and diffuse as compared with the other patterns. For this reason, and because the more soluble components may be masked, the boundaries between the phases could not be determined precisely. However, the X-ray analysis of electrolytically separated carbides has given consistently reproducible results

Jan 1, 1943

By Frank V. Hicks

THE following paper-in no sense a technical paper-is a summary of a safety campaign instituted by a coal-mining company to improve an unfortunate safety record. The experience should be suggestive equally to coal and metal-mining companies. With few precedents to follow in the beginning, the course was charted by trial and error. The endeavor, often disheartening, finally resulted in the capture of the most coveted safety trophy in the mining industry, "The Sentinels of Safety," awarded by the Hercules Powder Co. of Wilmington, Del., through the U. S. Bureau of Mines. The period described covers the 10-year interval, 1924 to 1933, the year 1933 being that for which the award was made. The coal company considered has produced annually for a number of years an average of 2,750,000 tons of coal, employing at various times from 1.800 to 3000 men. Prior to 1924, the

Jan 1, 1935

By Frank A. Herald

Through the generous cooperation of the authors of the papers in this chapter, a great wealth of fundamental data is being made available. The same plan of securing and submitting data will be carried forward next year, with the hope of making a nearer approach to complete presentation of the data contemplated in the plan. In order to conserve space, we are printing below such footnotes as have general application to Table 1 in the papers in this chapter: Footnotes to Column Headings Table I In areas where both oil and gas are produced, unless gas is marketed outside the field, such areas are included in column headed "Oil." Manufacture of casinghead gasoline and carbon black is interpreted as outside marketing of gas. Production per acre is determined by dividing into the number of barrels of oil the sum of the number of acres assigned to "Oil" plus such number of acres of the total assigned to "Oil and gas" as represents the portion thereof occupied by oil. Wells producing both oil and gas are classified as "Poducing oil only" unless gas from them is marketed off the lease. W. water; G. gas; A, air. Bottom-hole pressures are preceded by "e." All other figures represent pressures at casinghead with well closed. P, paraffin; A, asphalt; M, mixed. 0 Cam, Cambrian; Ord, Ordovician; Sil, Silurian; Dev, Devonian; Mis, Mississippian; MisL, Lower Mississippian; MisU, Upper Mississippian: Pen. Pennsylvanian; Per. Permian; Tri, Triassic; Jur. Jurassic; CreL, Lower Cretaceous; CreU. Upper Cretaceous; Eoc, Eocene; Olig, Oligocene; Mio. Miocene; Pli. Pliocene. 6, sandstone: SH, sandstone, shaly; Ss, soft sand; H, shale; L, limestone; LS, limestone. sandy; C, chalk; A, anhydrite; D, dolomite; Da. arkosic dolomite; GW, granite wash; P, serpentine. Figures are entered only for fields where the reservoir rock is of pore type. Figures represent, ratio of pore space to total volume of net reservoir rock expressed in per cent. "Par" indicates that the reservoir rock is of pore type but said ratio is not known by the author. "Cav" indicates that the reservoir rock is of cavernous type; "Fis," fissure type. A, anticline; AF, anticline with faulting as important feature; Af, anticline with faulting as minor feature; AM, accumulation due to both anticlinal and monoclinal structure; H, strata are horizontal or near horizontal; MF, monocline-fault; MU, monocline-unconformity; ML, monocline-lens; MC, monocline with accumulation due to change in character of stratum; MI, monocline with accumulation against igneous barrier; MUP, monocline with accumulation due to sealing at outcrop by asphalt; D, dome; Ds, salt dome; T, terrace; TF, terrace with faulting as important feature; N, nose; 9, syncline. Information will be found in text as indicated by symbols: A, name of author, other than above. who has compiled the data on the particular field; C, chemical treatment of wells; G, gas-oil ratios; P, proration; U, unit operation; R, references; W, water; 0. other information.

Jan 1, 1934

By K. K. Kohli, S. S. Peng, R. E. Thill

Introduction Since the adoption of the Surface Mining Reclamation and Control Act of 1977, which mandates that surface subsidence be an intergral part of the underground coal mine design, there has been a sudden rise of demand on guidelines for minimizing surface subsidence and its associated structural damages. Unfortunately there is no sufficient amount of systematic subsidence data to fill such a gap, although considerable research has been devoted to the subsidence induced damages of surface structures in the past. However, it was said that many surface subsidence surveys have been performed and monitored by coal companies during the past twenty years, and that it will be a great source of information for subsidence engineering design if they can be collected and assembled together. An effort was therefore initiated in the Department of Mining Engineering, West Virginia University, under contract with the U. S. Bureau of Mines in December 1978 to contact each individual coal company in the Northern Appalachian Coal Field for any surface subsidence survey data. After 10 months&apos; survey, the data collected include: 17 longwall panels and 2 room and pillar sections. The data in each panel and section cover the complete set of subsidence survey raw data, underground mine layout maps, surface topo maps, geological loggings showing the stratigraphic sequences and thickness of the overburden, and if available, locations and types of surface structures. On-site visits were followed to study the surface terraines and structures. Interviews were conducted with the owners of the surface structures in most cases about, if any, the history and characteristics of damages. Most subsidence surveys started with the first panel and ended with the second or sometimes, but rarely, the third panel. The first panel may be located in a virgin area but frequently it was adjacent to (on the tailentry side) a mined-out room and pillar section. It must be noted that all of the subsidence data is restricted only to the amount of vertical subsidence and that the horizontal displacement measurement was completely ignored. Primarily due to the fact that vertical subsidence is the most striking feature in a subsidence trough, which is mistakenly considered to be the only critical contributor to surface structural damages, and that a horizontal displacement survey is much more complicated and time-consuming.

Jan 1, 1981

By M. W. Cox, V. F. Hollister

Exploration for metallic mineral deposits is carried on by those special adaptations of methods which the explorer believes will yield most economically or satisfactorily the particular answer sought. In this project the usual methods of geologic observation, recording, and interpretation, when combined with magnetic geophysical methods and geochemical soil sampling, led to disclosures of appreciable zinc mineralization where none was visible in surface exposure. Since 1945 considerable work has been done with geochemical prospecting methods, chiefly in determining the presence and distribution of various elements existing in minor amounts in rocks, soil, vegetation or waters of mineralized areas. Such work, in which the U. S. Geological Survey has taken the lead, finds a ready place in the field repertoire of the exploration geologist as a supplement, not a substitute, for other methods. The Chollet project was carried out in 1951 by the American Smelting & Refining Co. near its Van Stone mine in northern Stevens County, Wash., in the area shown in Fig. 1

Oct 1, 1955