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By E. N. Doyle

Since the mid-1930's a number of plants, using the principles of heavy media separation, have been installed throughout the world. In cases involving lead, zinc or lead-zinc ores the reasons for the choice of this type of beneficiation process have fallen into four major categories: A) The economic recovery of additional distinctly separate products, such as dolomite limestone at the Mascot Plant (1) of the American Zinc Co., and the ferrosilicon produced by St. Joseph Lead Company. (2) B) The elimination of a large portion of run-of-the-mine ore prior to grinding and flotation, to allow increased throughput with low capital cost. Examples of this approach are the Levante and Ponente plants of the Montevecchio Company in Italy (3) and the frequent choice of the Sink-Float process by the Penarroya Company of Paris. C) The processing of a sedimentary deposit, in which the valuable mineral is contained in the matrix separating the boulders, as was the case at the St. Joseph Lead Company plant at Haydon Creek (4) and also at Bunker Hill Mining and Smelting, Kellogg, Idaho. D) The simplification of Around support programs in mines by allowing greater freedom of action in the extractive pattern. An example of this choice is Cominco’s Sullivan plant which came into being as part of an extensive proposal to update the mining, crushing, transportation, grinding and beneficiation processes. (5)

Jan 1, 1970

By Clair Upthegrove, Elbert S. Rowland

THE widespread interest in the alloys of beryllium with copper is due principally to the fact that certain compositions show very favorable precipitation-hardening characteristics and are, in fact, the strongest nonferrous alloys known at the present time. Investigations have been conducted by Masing and Dahl and others on the physical characteristics of ternary beryllium alloys, in an attempt to produce precipitation-hardening effects with a smaller amount of beryllium than that required in the binary copper-beryllium alloys (2.0 to 2.5 per cent Be). The results of these investigations show that ternary alloys of beryllium with Cu-Sn, Cu-Al and Cu-Zn, among others, exhibit promising improvements in physical properties after precipitation-hardening treatment and, while the increases in properties obtained are not as high as those realized from the binary copper-beryllium alloys, excellent properties are: obtained with beryllium contents averaging about one-half the amount required in the binary alloys. This paper presents the results of an investigation of the equilibrium relations of certain alloys containing copper, tin and beryllium. The alpha-phase boundary of the ternary system is given for alloys containing from. 0 to 1 per cent beryllium. The equilibrium conditions beyond the alpha-phase boundary are presented for alloys containing up to 32 per cent tin and 1 per cent beryllium. The data were collected by means of

Jan 1, 1935

By T. E. Kihlgren

SYSTEMATIC data are presented on the relation of composition of nickel silvers to color, tarnish resistance, hardness and liquidus temperatures, for alloys containing up to 30 per cent nickel and 50 per cent zinc, further modified at certain nickel and zinc contents by 0 to 8 per cent of tin and 0 to 10 per cent of lead. Attention has also been directed, using a still more limited range of alloys, toward a study of tensile properties and such casting properties and characteristics as fluidity, shrinkage and pressure tightness. In some of these, rather broad ranges of composition are dealt with; in others, it has been expedient to focus attention on the Federal Specification 20 per cent nickel silver casting alloy, WWP-541. INTRODUCTION The demand for an alloy essentially white in color, which could be cast and worked by simple methods and which possessed strength and corrosion-resisting properties superior to the usual brasses, led to the discovery and early use of cupronickel alloys containing zinc, and some-times tin, lead and other metals. This type of alloy was generally known as German silver until the war, when the term "Nickel Silver" became generally accepted. The element principally responsible for the white color of the alloy and for its strength and corrosion resistance is nickel, which may constitute from 8 to 30 per cent of the alloy. The functions of the other elements will be described later. The manifold uses of nickel silver are largely due to its color, corrosion resistance, ease of casting, fabrication, joining and rather moderate cost. In many instances the alloy is finished by grinding and polishing while in others it may be finished with a silver or nickel plus chromium plate. Electroplates

Jan 1, 1935

By Axel Hultgren

IN ingots of silicon-killed carbon steel made without addition of - aluminum, transparent spherical or nearly spherical inclusions, up to about 0.15-mm diameter, are generally present. They may be glassy or crystallized, wholly or partially. In steels of high carbon contents they consist of silica,4,12 in steels of lower carbon contents arid, in consequence, higher oxygen contents, of iron-manganese-silicate with higher iron and manganese contents the lower the carbon content. Small silicate inclusions, about 0.01 mm or smaller, may occur, just as sulphide inclusions do, in portions that have been the last or nearly the last to freeze,10,12,17 this location being verified by primary etching.10 Hence, it may be concluded that they have separated from liquid steel that has become enriched in oxygen through segregation during freezing. Silicate inclusions with a diameter larger than about 0.02 mm appear, at least in ingots of moderate size, to be distributed at random in relation to the primary structure and therefore may be assumed to have existed as droplets in the liquid steel before freezing started at the point in question. The average size of such large inclusions has been found to increase toward the axis17 and their amount to increase from the top downward in the axial region .2,10 It has been assumed that this accumulation is a result of the droplets being brought down by the slowly settling metal crystals.2 It has been suggested that large silicate inclusions generally form,6 or may form," by coagulation of smaller ones, or by small drops being caught by larger ones during the rising of the latter.9 The occasional occurrence of a large inclusion surrounded by a swarm of small ones has been taken as a proof of this mechanism but, as suggested later, may be explained in another way. It has been pointed out that an inclusion droplet in the liquid steel may grow at the expense of an adjacent one, which implies diffusion of soluble inclusion-forming elements in the liquid steel.15 Further, it has been pointed out that, on cooling in ladle or mold, the metal-silicate equilibrium is displaced in the direction of separation of silicate. Thus inclusions may grow in size and amount.2,3,8,12,13,17,19,20 The exposure of the liquid steel to the oxygen of the air during tapping and pouring, and the consequent reaction, has been mentioned as a source of the formation of inclusions19,20 but this possibility has not received particular attention. Further, the admixture of furnace slag during tapping' or of refractory material from various sources1,20 has been considered. The inclusions due to the latter may be recognized, however, through their resistance to hydrofluoric acid, imparted by the alumina content. Silicate inclusions, are often referred to as. the natural and inevitable product of reaction on adding silicon or silicon

Jan 1, 1948

By Henry S. Drinker

THE Musconetcong tunnel is situated in New Jersey, near the line of the Central Railroad of New Jersey, about twelve miles from Easton, on the Easton and Amboy Railroad, the latter being the extension of the Lehigh Valley Railroad to tide-water. Up to the present time, the terminus of the Lehigh Valley Railroad has been at Phillipsburg, N. J., opposite Easton, passengers connecting there with New York by the Morris and Essex (D. L. and W.) and New Jersey Central lines; freight and coal being forwarded by the Morris and Essex to tide-water at Hoboken, and by the Central Railroad to Elizabethport and Port Johnson ; also, by the Belvidere and Delaware connections through Trenton to South Amboy.

Jan 1, 1875

By J. E. Johnson

Discussion of the paper of Mark A. Amnion, presented at the Cleveland meeting October, 1913, and printed in Bulletin No. 70, October, 1913, pp. 1167 to 1 79. J. E. JOHNSON, JR., Ashland, Wis.:-Mr. Amnion's paper is of great value and it is not with any desire to reflect. on it that I wish to make some comments on the use of the scleroscope. We obtained one on trial some months ago and made very extensive tests with it, but without getting very satisfactory results. The readings on good car-wheels and bad ones were just about the same, but the factor in its use most likely to produce erroneous results is a variation in the thickness of the specimen being tested. In order to find out something on this subject we cut a thin disk, about -1,: in. thick, off a brass rod; then one 0.25 in. thick, and another about 1 in. thick, put the surfaces of all in about the same condition and tested them with the scleroscope. The readings varied widely; the resilience of the anvil evidently entered to a very high degree on thin pieces. By putting a soft cushion between such a thin specimen and the anvil, and forcing it up against the tube, the softness of the cushion cut off the resilience of the anvil and the results were more like those of the thick specimens. After a thickness of 1 in. was passed, the specimen seemed to have mass enough so that the resilience of the anvil no longer played an important part, and above that thickness results on different materials would be comparable, even though the thicknesses differed. But in order to get comparable results on thin specimens the thickness of those being tested should be the same. I should like to ask how the variations introduced in this way were overcome, so as to get strictly comparable results. Mr. AMMON :-.I have not had much experience in that, but the scleroscope is simply an indication of the surface harden-

Dec 1, 1912

By B. F. Oliver, F. Garofalo

Gas-metal heterogeneous reactions and zone-lrelting were sinultarneously employed to produce several high-purity irons with low interstitial contents in a levitating- zone melter. Successive zone-tneltitzg pusses were made in carious sequences of atmospheves which included prepuvified tank hy-drogeta, water vapor hydrogen, palladiuril-purified hydrogen, and vacuunm of 2 x 10-6 Torr. Different irons ranging in purity from 99.89 to 99.996 pct with residual curbon contents of 17, 8 to 10, and 3 to 5 ppm have been Drepared. No measuvable gradient in the residual carbon content was observed along the entire zone-melted length (6-10 in.) in I-ilz.-diameter bars. The absence of a carbon-concentration gradient in the solid indicates an apparent distvihution coefficient of 1, an unusual condition. Internal friction, solid-state extraction, and hot-hardness results indicate that the level of mobile carbon in a iron depends on the gas-metal heterogeneous reactions employed. Purification under an oxidizing atmosphere resulted in the immobilization of nearly all of the carbon present at leuels of 10 ppm or less. Continuation of purification in a reducing atmosphere veturued the carbon to a state of mobility which was aguin reversed by further purification in all oxidizing atmosphere. The immobilization of curbon at "vesidual levels " is believed to be associated with a strong interaction between carbon and oxygen atoms. frons with low carbon and nitrogen contetzts which did not exhibit a hot-hardness peak were produced after zone ynelting in vacuum. CARBON, nitrogen, and oxygen have strong and well-known effects on many properties of iron. These effects persist even at concentrations of 5 to 20 ppm. The intent of the present investigation was to establish procedures for the preparation of high-purity iron with concentrations of these elements in the range of 5 to 20 ppm and lower. The results reported here deal with the procedures employed to prepare high-purity iron, and with observations on the behavior of certain elements at "residual levels": particularly carbon. The details of the (levitating) zone melter in which the final purification steps are performed and the necessary control of the pertinent solidification variables have been described previously.1,2 MATERIALS AND PROCEDURES Commercial electrolytic iron was induction vacuum-melted and cast into 30-lb ingots. Melt additions and ingot analyses for carbon, oxygen, and nitrogen are noted in Table I. All ingots were melted in stabilized zirconia crucibles conditioned with one iron wash heat. Middle sections of the ingots were forged to 1-1/4-in. rounds, machined to 1-in.-diameter bars, then cut to 36-in. lengths. The zone-melting operations were performed on six iron bars (A to F) at a freezing velocity of 2 in. per hr with the freezing interface rotating2 at 200, 300, or 400 rpm. Liquid zones were passed through the bars in various sequences of atmospheres, Table 11, including prepurified tank H2, palladium-purified Hz, wet H2, and system vacuum of 2 x 1018 Torr. Wet-Hz atmospheres were obtained by bubbling palladium-purified Hz through water exhibiting a resistance of 3 megohms. This water was heated with a platinum-immersion heater and was degassed prior to use. Zone melting in a wet-HZ atmosphere resulted in oxidation of the elements which are oxi-dizable with respect to iron. Fine oxide particles were observed on the surface of the liquid zone, and were encased in the bar surface with the passage of the molten zone. Between each zone pass, the surface of the bar was removed by filing and deep etching; this was continued until the oxide formation ceased. The filings were magnetically separated and the residues analyzed by optical spectroscopy. These were especially high in silicon and manganese. Samples were removed from the iron bars, with few exceptions, following each zone-melting operation. A 0.08-in.-thick disc was cut with an Al2O3 cut-off wheel at a point 1/2 in. above the beginning of freezing. Material from each disc was used for hot-hardness measurements, resistivity-ratio measurements, and carbon, nitrogen, and oxygen analyses. Analyses for most other elements were

Jan 1, 1965

By C. W. Binckley, F. R. Burgess, E. R. Haymaker

A method of establishing stabilized back-pressure curves for gas wells producing from formations of extremely low permeability is presented. Actual well performance under many different operating conditions is shown by the stabilized back-pressure curve. By use of the method. it is possible to conduct back-pressure tests with a critical-flow prover on wells that stabilize slowly, and save approximately 88% of the gas ordinarily vented to obtain satisfactory test data, with a great reduction in time required for testing. INTRODUCTION The reasons for establishing dependable back-pressure curves on gas wells have been pointed out by previous publications. The publication most referred to. of course, is the United States Bureau of Mines Monograph 7, titled "Back-Pressure Data on Natural Gas Wells and Their Application to Production Practices". The technique generally established therein has been accepted and used by many engineers; and, when proper tests are conducted, the results can be used for the analysis and solution of several practical problems concerning field operation and development. Even where formations of low specific permeability are encountered, the determination of a well's actual performance by the back-pressure test method permits the engineer to analyze many problems in individual well operation and also to predict necessary future field development. Such problems as the determination of the ability of a well to produce into a pipe line at a predetermined line pressure, the design of gas gathering systems and meter settings, and the determination of the time and the number of wells required to be drilled to meet future market obligations, can be solved, in part., by the use of a reliable back-~ressure curve. In addition, the computed well delivery rates determined by data from backpressure tests ordered by state regtilatory bodies, when compared with the true back-Pressure curve, permit the operator to ascertain whether such data represent unstable or relatively stabilized delivery rates for given pressure conditions of the well. The technique of back-pressure testing, as described in this report, was developed by Phillips Petroleum Company engineers from data obtained during a testing program that started in 1944 and has been continued to date. Three hundred and eleven back-pressure tests were conducted on 299 wells located in the southern part of the Hugoton Field. The gas-bearing zone is composed of several dolomitic formations of the Permian Age; the important ones are the Herington, Upper Krider, Lower Krider, and Winfield. The average bottom-hole temperature is approximately 91 °F.. and the initial wellhead shut-in pressures range from 400 to 440 psig. The spacing pattern is 640 acres per well with each well located near the center of the section. The range of back-pressure potentials on wells tested was from 500 to 23,000 Mcfd. All gas wells were acidized, and the quantity of acid used, expressed in 1574 hydrocloric acid, varied from 12,000 to 22,000 gallons per well. The quantity and concentration of each treatment depended on the stage, the formation being treated, and experience gained from previously completed wells. The gas in the Hugoton Feld is a "dry" gas. It has a gasoline content of approximately 0.25 gallons per thousand cubic feet, as determined by charcoal test, and its specific gravity averages about 0.71 as compared to air (air = 1.00 at 60°F.). Of the wells tested, 71 were completed with 7" casing, 3 with 9 5/8" casing, and 1 with 6%" casing set on top of the upper producing formation with the well bore through the gas bearing formations being open hole. Two hundred and twenty-four were completed with 5 1/2'' O.D. casing set through the gas bearing formations and perforated. For the purpose of establishing reliable back-pressure curves in the area, Phillips Petroleum Company personnel has computed data on the basis of 24-hour flows per point. Early in the program, many tests were actually permitted to flow 24 hours to obtain data for each plotting point, at great expense in man power and time. Presently, however, such tests have been replaced by tests of short duration flows which can be made to effect results that correspond to the tests obtained by flows of much longer duration. METHOD When a gas well producing from a reservoir of low permeability is opened for production through a constant size orifice, both the rate of flow and working pressure decline. first at a high rate and later at a lower rate until after several hours the decline becomes difficult to ascertain. In this paper the rae of flow and working pressure are considered to be stabilized when it becomes difficult to observe changes in working pressure during a period of three hours by the use of a deadweight pressure gage. Stalibization of pressure in the literal sense is never obtained in a producing gas well. In formations of low permeability. such as those in the Hugo-ton Field, most wellhead working pressures approach stabilization closely enough to be used satisfactorily in the determination of a back-Pressure potential curve after flow periods of 24 hours. We shall therefore describe the backpressure curve calculated from ohserved rates of flow and working pressure at the end of 24-hour flow periods.

Jan 1, 1949

By E. R. Haymaker, C. W. Binckley, F. R. Burgess

A method of establishing stabilized back-pressure curves for gas wells producing from formations of extremely low permeability is presented. Actual well performance under many different operating conditions is shown by the stabilized back-pressure curve. By use of the method. it is possible to conduct back-pressure tests with a critical-flow prover on wells that stabilize slowly, and save approximately 88% of the gas ordinarily vented to obtain satisfactory test data, with a great reduction in time required for testing. INTRODUCTION The reasons for establishing dependable back-pressure curves on gas wells have been pointed out by previous publications. The publication most referred to. of course, is the United States Bureau of Mines Monograph 7, titled "Back-Pressure Data on Natural Gas Wells and Their Application to Production Practices". The technique generally established therein has been accepted and used by many engineers; and, when proper tests are conducted, the results can be used for the analysis and solution of several practical problems concerning field operation and development. Even where formations of low specific permeability are encountered, the determination of a well's actual performance by the back-pressure test method permits the engineer to analyze many problems in individual well operation and also to predict necessary future field development. Such problems as the determination of the ability of a well to produce into a pipe line at a predetermined line pressure, the design of gas gathering systems and meter settings, and the determination of the time and the number of wells required to be drilled to meet future market obligations, can be solved, in part., by the use of a reliable back-~ressure curve. In addition, the computed well delivery rates determined by data from backpressure tests ordered by state regtilatory bodies, when compared with the true back-Pressure curve, permit the operator to ascertain whether such data represent unstable or relatively stabilized delivery rates for given pressure conditions of the well. The technique of back-pressure testing, as described in this report, was developed by Phillips Petroleum Company engineers from data obtained during a testing program that started in 1944 and has been continued to date. Three hundred and eleven back-pressure tests were conducted on 299 wells located in the southern part of the Hugoton Field. The gas-bearing zone is composed of several dolomitic formations of the Permian Age; the important ones are the Herington, Upper Krider, Lower Krider, and Winfield. The average bottom-hole temperature is approximately 91 °F.. and the initial wellhead shut-in pressures range from 400 to 440 psig. The spacing pattern is 640 acres per well with each well located near the center of the section. The range of back-pressure potentials on wells tested was from 500 to 23,000 Mcfd. All gas wells were acidized, and the quantity of acid used, expressed in 1574 hydrocloric acid, varied from 12,000 to 22,000 gallons per well. The quantity and concentration of each treatment depended on the stage, the formation being treated, and experience gained from previously completed wells. The gas in the Hugoton Feld is a "dry" gas. It has a gasoline content of approximately 0.25 gallons per thousand cubic feet, as determined by charcoal test, and its specific gravity averages about 0.71 as compared to air (air = 1.00 at 60°F.). Of the wells tested, 71 were completed with 7" casing, 3 with 9 5/8" casing, and 1 with 6%" casing set on top of the upper producing formation with the well bore through the gas bearing formations being open hole. Two hundred and twenty-four were completed with 5 1/2'' O.D. casing set through the gas bearing formations and perforated. For the purpose of establishing reliable back-pressure curves in the area, Phillips Petroleum Company personnel has computed data on the basis of 24-hour flows per point. Early in the program, many tests were actually permitted to flow 24 hours to obtain data for each plotting point, at great expense in man power and time. Presently, however, such tests have been replaced by tests of short duration flows which can be made to effect results that correspond to the tests obtained by flows of much longer duration. METHOD When a gas well producing from a reservoir of low permeability is opened for production through a constant size orifice, both the rate of flow and working pressure decline. first at a high rate and later at a lower rate until after several hours the decline becomes difficult to ascertain. In this paper the rae of flow and working pressure are considered to be stabilized when it becomes difficult to observe changes in working pressure during a period of three hours by the use of a deadweight pressure gage. Stalibization of pressure in the literal sense is never obtained in a producing gas well. In formations of low permeability. such as those in the Hugo-ton Field, most wellhead working pressures approach stabilization closely enough to be used satisfactorily in the determination of a back-Pressure potential curve after flow periods of 24 hours. We shall therefore describe the backpressure curve calculated from ohserved rates of flow and working pressure at the end of 24-hour flow periods.

Jan 1, 1949

By S. Floreen

Seven iron alloys ranging from 5 to 12 pct Ni and 5 to 14 pct Cr were studied. All alloys transformed to bcc massive martensites. Tempering increased the strengths , probably because of relief of residual stresses generated by the martensite transformation. The major strengthening mechanism appeared to be solid-solution hardening by nickel and chromium. Studies of the work-hardening behaviw, of the effects of prior austenite grain size, and of the effects of changing strain rate and test temperature gaue results very similar to iron or low-alloy steels. Increasing nickel contents markedly improved the toughness at subzero temperatures. Studies of the flow properties did not, however, indicate the reason for the beneficial effect of nickel on toughness. The marine atmosphere corrosion resistance of the alloys was improved primarily by chromium additions, but increasing nickel contents were also beneficial at low levels of chromium. J\ number of maraging and PH stainless steels are strengthened by precipitation hardening in a low-carbon Fe-Ni-Cr martensite matrix. To some extent the resultant properties of these steels must depend upon the properties of this matrix. The present study therefore was conducted to evaluate the transformation characteristics and mechanical properties of a series of Fe-Ni-Cr martensitic ternary alloys. A limited evaluation of the corrosion resistance of the alloys in marine atmosphere was also made. ALLOY PREPARATION Seven 100-lb air induction melts were prepared using electrolytic iron, nickel, and chromium metal additions. The initial Fe-Ni charge also contained 0.05 wt pct graphite to produce a carbon boil during melt down. After melting of the base charge, the heats were refined with 0.1 wt pct additions of manganese, silicon, aluminum and titanium and poured into cast-iron molds. The ingots were homogenized at 1250°C and uni-directionally hot-rolled to 2-in. plate. They were then homogenized another hour at 1250°C, and unidirection-ally hot-rolled to %-in. plate at a finishing temperature of approximately 1050°C. The compositions of the heats are given in Table I. Two additional heats were prepared as 40-lb vacuum-induction melts using electrolytic iron, nickel, and chromium metals, and commercially pure molybdenum chips. A carbon boil, and 0.1 wt pct additions of aluminum and titanium were again employed, but manganese and silicon were not added. The heats were converted to %-in. plate using the procedure described above. The compositions of these heats are included in Table I.

Jan 1, 1967

By W. R. Hibbard

It has been proposed1 on the basis of slip and flow that the ideal deformation texture of drawn wire for face-centered cubic metals is a (111) direction parallel to the wire axis. Under these considerations, an intermediate [loo] texture is permissible but should eventually change to the stable [Ill] orientation. This theory does not explain why copper and its alloys containing up to about 30 pct nickel, 5 pct zinc and 1 pct aluminum were found to have a double [Ill], [100] texture, while alloys with at least 8 pct zinc and 2 pct aluminum developed essentially a single [Ill] texture.1,2 It does suggest, however, that the [loo] component of the former alloys should disappear with additional deformation.3 Some evidence exists to support this suggestion. Howald4 reported that annealed copper wire previously drawn 93.8 pct and 98.5 pct developed a single [Ill] texture. Since, in wire, the drawn and annealed textures are similar, these wires probably had a single [Ill] deformation texture before annealing. In addition, although cold rolled polycrystalline copper and 80-20 brass were found to form different types of pole figures,5,6 single crystals of these metals when rolled from the stable (110) [112] orientation were found to produce essentially the same polo figure.7.8 It may be, therefore, that while the addition of solute elements changes the path by which the final texture is obtained, the final texture is not changed. Experimental Results The wires remaining from the previous investigation1 already drawn about 50 pct reduction in diameter were further drawn to 86 pct and then to 96.4 pct total reduction in diameter. The textures were determined after these stages by transmission X ray photograms taken with a copper K-alpha beam rotated 0 degrees toward the wire axis. It was found that the ratio of the [111].] and [100] intensities of the double texture in copper and its alloys containing 0.94 pct aluminum, 30.70 pct nickel, 2.61 pct zinc and 4.99 pct zinc increased from about 3:l for the 50 pct reduction to about 9:l for the 86 pct reduction. After 96.4 pct reduction, these wires exhibited essentially a single [lll] texture. Summary Thus, the drawn wire deformation texture of copper and its alpha solid solution alloys containing aluminum, nickel or zinc is essentially a single [Ill] texture as predicted by theoretical considerations of slip and flow.' For copper and its alloys containing up to about 1 pct aluminum, 5 pct zinc and at least 30 pct nickel, an intermediate [loo] component is found after about 50 pct reduction in diameter, but disappears after about 95 pct reduction in diameter. For alpha solid solution alloys containing at least about 2 pct aluminum and 8 pct zinc the single [Ill] texture is developed considerably more easily and is found after about 50 pct reduction in diameter. No explanation of this compositional effect is apparent. Similar work is contemplated for cold rolled and cold compressed alloys. References 1. w. R. Hibbard, Jr. and M. K. Yen: Trans. AIME 175, 126. Metals Tech., Feb. 1948, TP 2334. 2. W. R. Hibbard, Jr. and D. E. Trout, 11: Trans. AIME 185, 620. Jnl. of Melals, Sept. 1949, TN 18. 3. W. R. Hibbard. Jr.: Disc. of R. M. Brick's paper on Deformation Textures, ASM Symp. on Cold Working of Metals, Oct. 1948. 4. T. S. Howald: Disc. of Ref. 1. Trans. AIME, 175, 126. Melals Tech. Aug. 1948, TP 2449. 5. R. M. Brick, D. L. Martin and R. P. Angier: Trans. ASM (1943) 31, 675. 6. 0. Dahl and F. Pawlek: Zlsch. Melall. (1936) 28, 266. 7. C. S. Barrett and F. W. Steadman: Trans. AIME (1942) 147, 57. 8. J. E. Burke and C. S. Barrett: Trans. AIME 175, 106. Melals Tech., Feb. 1948. TP 2327.

Jan 1, 1950

By Paul E. Richardson, Edwin E. Maust

Cyclic voltammetry and surface potential (photovoltage) measurements have been carried out on galena electrodes in sodium tetraborate solutions with added HC1 and NaOH to adjust the pH over the range 2 to 13. The first technique shows that the surface species formed on moderate anodic polarization and reduced on subsequent cathodic polarization are the same over the entire pH range. At anodic potentials, a soluble metal species and excess sulfur are formed; at cathodic potentials, sulfur is reduced to a soluble species. More importantly, excess surface sulfur is formed spontaneously under zero current conditions in alkaline solutions. This has been shown to occur on both polished surfaces and on virgin surfaces produced by in situ cleavage under the electrolyte. The photovoltage gives some insight into the charge and potential distribution at the galena surface. This is found to depend on past electrochemical history and the n- or p-type semiconducting character of the electrode and is interpreted in terms of changes in the surface stoichiometry that occur during reduction or oxidation. The effect of surface stoichiometry on subsequent xanthate interactions is discussed.

Jan 1, 1976

By Nick A. Hasenack, Heinz Kister, Rolf B. Vogel, Kees H. van Toor

A full survey of the laboratory and blast furnace tests carried out on two types of acid pellets is given. From the lab tests it appears that type B has a better low temperature disintegration index and a lower reducibility index than type A. The chemical composition and swelling indexes do not differ for both types. From the blast furnace test periods, carried out with a charge of 45% of pellets and 45% of sinter, it follows that both types of pellets lead to the same pig-iron production, blast furnace permeability, and blast furnace dust production. It also can be concluded that type B pellets cause a significantly higher coke consumption.

Jan 1, 1977

By W. H. Bassett, C. Davis

Although brasses and bronzes have been made for ages, a systematic study of their physical properties has been carried out only during the years of the present century. Among these properties may be included those which are to be detected by means of microscopic examination; in other words by the science of metallography. The earlier workers in this field, both in this country and abroad, gave their attention to steel. When the senior author explored the situation in 1902, there was little encouragement to be found in undertaking the study of the non-ferrous alloys. A start was made, and the metallography of the brasses and bronzes, as well as of the copper-nickel-zinc alloys developed materially under his direction. Annealing experiments were begun in 1902, and in the succeeding years the effect of temperature, and the influence of previous working, on the grain size of brass were studied. The conclusions so well known and widely published today were largely reached during those earlier years. In 1905 the first complete annealing series were made. By this it is meant that brass and copper sheet, 5 B & S Nos. hard, was machined into tensile test specimens, then annealed under accurate control for 30 min. at temperatures up to the melting point of the material. Various determinations were made, including tensile strength and elongation in 2 in. There rapidly followed similar series on all of the copper-zinc alloys from 100 to 60 per cent, copper, on the bronzes, cupronickels, and on copper-zinc-nickel alloys. At this point there was published by Grard, in October, 1909,' the very comprehensive and complete work on the tensile properties of cartridge brass, 90-10 copper-zinc, and electrolytic copper. The excellent photomicrographs in that paper illustrated the changes in structure produced by cold rolling as well as by annealing at different temperatures, but where Grard's work was confined to copper and to two alloys, the investigations in this laboratory have been over the entire fields of the commercial copper-zinc alloys, copper-tin alloys, representative copper-nickel and copper-nickel-zinc alloys as well as aluminum bronzes and others of a more special nature.

INTRODUCTION This chapter summarizes characteristics of porphyry copper deposits within the Cordilleran orogen east of the Coast Range plutonic complex of the Yukon and British Columbia and south to the Columbia River plateau and the Idaho batholith. Porphyry copper deposits in this area reflect a geologic environment different from that found for mineralized intrusions elsewhere in the Cordilleran orogen, both to the south in the United States and Mexico and to the west in Alaska. A section on the Tertiary Cascade porphyry copper province is included herein. The Cascade province is considered separately because its deposits display a unique mineralogy and age of mineralization. That portion of the Cordilleran orogen described in this chapter is shown in Fig. 32, with the Cascades shown in Fig. 39 (see p. 114). The regional geology of this area has been described by Monger, et al. (1972), Hollister (1974), Wolfhard and Ney (1974), Field, et al. (1974), and Stacey (1974). Each offer slightly differing views on the post-Mississippian evolution of the geology in this porphyry copper province. The descriptive geology in this chapter has benefited from many discussions with J. E. Armstrong and J. W. H. Monger. Two separate petrologic models have been used popularly to categorize porphyry copper deposits in this area, a diorite and a quartz monzonite model. The diorite model, which involves a mineralized quartz-free pluton, has also been called the alkalic type (CZM Special Volume 15, 1976, and Soregaroli, 1975) and the syenite suite (Sutherland Brown, et al., 1971). The quartz monzonite model has also been named the calcalkalic type (CZM Special Volume 15, 1976) and includes mineralized quartz-bearing plutons compositionally ranging from quartz diorite to granite, with the igneous phase closest to ore in time and space commonly being quartz monzonite.

Jan 1, 1978

By Spurr

CONTENTS. [ ]

Jan 1, 1913

J. D. Fast and J. L. Meijering (Philips Research Laboratories, N. V. Philips' Gloeilampenfabrieken, Eindhoven, Netherlands)— After the departure of our friend Dijkstra to the United States, investigations on the effect of alloying elements on the behavior of nitrogen in a iron were continued in Eindhoven. We too found internal friction curves with two separate peaks for iron containing nitrogen in addition to 0.5 atomic pct V or 0.5 atomic pct Mo. Our first publication on these investigations" appeared almost simultaneously with the paper now under discussion. At first sight our experimental results seem to be in harmony with their conclusions, but a closer examination reveals that in the case of the Fe-V-N alloy the abnormal peak is not controlled by one time of relaxation only. Whereas iron containing 0.5 atomic pct Mn or Mo absorbs an amount of nitrogen of about the same magnitude as that absorbed by pure iron under identical conditions, iron containing vanadium absorbs in addition one nitrogen atom for every vanadium atom. This last amount, far exceeding the first amount in the case under consideration, combines chemically with the vanadium and causes no internal friction. The "free" nitrogen in the vanadium alloy gives rise not only to a damping peak corresponding to that in pure iron but— due to the presence of VN particles in the metal—also to the abnormal peak at higher temperatures. The VN particles create interstitial sites around themselves where the free nitrogen atoms are bound much tighter than in the normal interstices. These abnormal interstices, therefore, will capture free nitrogen atoms rapidly, whereupon these give rise to the abnormal damping. The binding energy in the abnormal interstices is not the same for all, and with coarsening of the VN precipitate the distribution of these energies is displaced toward the side of stronger binding. This is deduced from a shift of the summit of the second peak toward higher temperatures (from 80" to 88°C in our experiments) caused by prolonged heating at 950°C. From the intermediate state where they cause the abnormal damping, the nitrogen atoms pass over rather rapidly into the fully precipitated state (iron

Jan 1, 1954

By Nathaniel Arbiter, Chas. H. Behre

Two outstanding factors characterize most undertakings in the mineral industries: (1) mineral deposits are not equally distributed over the earth but are localized by natural processes, and (2) the mineral industries are largely based upon wasting assets. Neither of these factors is invariably true, for a few mineral materials, such as water, are essentially world-wide and others are replaced periodically by processes not unlike crop production. Indeed, with some, such as the salts in the sea, the supply is cyclic in short or long periods, whereas others, like water, though locally or periodically in short supply, are essentially inexhaustible. But to the extent that most minerals are limited to certain areas and are "permanently" consumed, any industry founded upon them, by implication, demands great care in planning for the most effective extraction-the essence of wise and conservative expenditure. Several less unusual yet also truly fundamental factors in the economics of the mineral industry are those involving (1) the various kinds and properties of mineral materials, which influence their use; (2) their geologic and geographic availability; and (3) the 'techniques unique to their discovery, exploration, and utilization. This chapter is designed primarily as a brief background for later ones and as a summary of the several unusual or at least special factors and of their effect upon the economics of the mineral industry. The social and political and especially the economic aspects of the industry are the main subjects of this volume and are dealt with in extended fashion in subsequent chapters. Fundamental Characteristics of Mineral Deposits DEFINITIONS Minerals are naturally occurring compounds of nonliving matter, each technically defined as having ( 1 ) a chemical composition that may vary

Jan 1, 1964

By T. A. Rickard

Among the names which won a world-wide fame during the golden age of the early fifties, Bendigo and Ballarat were to Australia, what the Yuba and Grass Valley were to California. The map of Victoria did not for a long time show the name of old Bendigo;* for this first and more distinctive name was replaced with the more English Sandhurst, just as the alluvial diggings gave place to quartz mining. Towards the close of last pear, steps were taken to give back the old name, as associated with the early days of rich alluvium, and more suggestive than the application taken secondhand from an English military academy. History. The first discovery of gold? in this district, was made in the autumn of 1851 ; but there has never been any certainty as to the day or the man. At that time the country around Bendigo Creek was a part of the Ravenswootl sheep-run, and its resemblance to the Forest Creek district (now Castlemaine), induced the first prospecting. It was late in November when the "rush" broke out; the shepherds left their flocks; the sylvan solitudes were disturbed by * The name of Bendigo is said to have been derived from a hut-keeper on the Ravenswood sheep-run, who on account of his fondness for " fisticuffs " was nicknamed Bendigo, after the prize-fighter of that name. It is not aboriginal, as is often supposed, but Spanish ; and equivalent to our Benedict. There must always be some confusion between the two names of Sandhurst and Bendigo; the town, and with it the gold-field, having been three tinies named. Several other old familiar names have been likewise unfortunately replaced by second-hand English ones; so that an old digger talks of Forest Creek when he means the modern Castlemaine, Mt. Ida for Heathcote, Growler's Creek for Bright, etc. I shall use the names Sandhurst and Bendigo interchangeably. The first discovery of gold in Australia, was made by E. H.Hargraves, February 12, 1851, near Bathurst in New South Wales. In August of the same year the discovery at Buninyong, near Ballarat, inaugurated the first of a series of rushes to the Victoria gold-fields.

Jan 1, 1892

Jan 3, 1950