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By P. D. Merica

Certain compositions of the light, i:e., aluminum-rich, alloys of aluminum with magnesium and copper have become quite well known within the past ten years under the name of duralumin. These alloys are used for rolling and forging and can be so treated as to develop quite remarkable mechanical properties. Thus a properly heat-treated alloy containing about 4 per cent. of copper and about 0.5 per cent. of magnesium, rolled into sheet or rod, will have a tensile strength of approximately 55,000 lb. per sq. in. (3866 kg. per sq. cm.) with an elongation in 2 in. (50.8 mm:) of about 15 per cent. This alloy, duralumin, was developed by Wilm,1 and its properties more fully described by Cohn.2 The authors considered it worth while to investigate the mechanical possibilities of the light alloys of two somewhat analogous ternary series; namely, of aluminum-magnesium-nickel and of aluminum-magnesium-manganese, to study the effect of variation of composition upon mechanical properties within the alumimum-rich group of the aluminum-magne-

Jan 7, 1919

By E. P. Mathewson

A Discussion of the Paper of E. P. Mathewson, presented at the New York Meeting, April, 1907, and printed in Bi-Monthly Bulletin, No. 13, January, 1907, pp. 7 to 14. PROF. HENRY M. HOWE, New York, N. Y. (communication to the Secretary *) :-The results presented in Mr. Mathewson's paper are of very great interest. Perhaps the most interesting is that shown in Table I. and Fig. 1, in which the arsenic decreases in 10 min, from 0.22 to 0.07 per cent. This is such a large decrease that it is to be hoped that Mr. Mathewson will verify it by repeating his tests with a matte of similar composition. This is particularly to be desired, because the simultaneous removal of sulphur appears to be very small. All three blows further agree in showing that the removal of arsenic is in the very early part of the blow. The fact that the removal of arsenic then ceases abruptly cannot be explained completely by the fact that the arsenic has fallen so low as by its lowness to resist further removal, because in the first blow the arsenic becomes stationary at 0.06 per cent., whereas in the third blow it does not become stationary until it has fallen to 0.034 per cent. The abrupt ending of the re¬moval of arsenic is more likely to find its explanation in the composition of the slag, and it is to be hoped that. Mr. Mathewson will supplement these extremely valuable data with others in which the composition of the slag at the same time shall be given. The sudden rise of arsenic toward the end of the third blow I suppose must be referred to an error in sampling or analysis. Mr. Mathewson speaks on page 14 of the "percentages of iron . . . volatilized during the first period." Is it his meaning that all this iron is really volatilized, or does he mean that the iron is scorified and the sulphur volatilized ?

Jul 1, 1907

By D. E. Light, J. Y. Somnay

The use of alkyl acid phosphates and their alkali salts as collectors for the uranium minerals brannerite and uranothorite was investigated. In particular a detailed flotation study was carried out using isooctyl acid phosphate as a promoter. Tests were conducted on an Elliot Lake ore analyzing 0.11% U 3 O 8, chiefly as brannerite, and approximately 9% pyrite. Pyrite was floated with conventional reagents; the flotation of brannerite from the sulfide tails was studied to determine the optimum pH and pulp density to employ with isooctyl phosphate. 4 uranium recovery of over 90% was possible with a selectivity index of 8.95 when these tails were floated at 17% solids and a pH of 1.7. The effect of various modifying agents was also investigated. Aluminum sulfate, lactic acid and sodium silicate improved the selectivity of collection yielding selectivity indices of 9.5 to 11.5. Ferric chloride was found to be a depressant for brannerite. A Bancroft ore which analyzed 0.13% U308, and contained uranothorite was also amenable to flotation using isooctyl acid phosphate. The composite uranium concentrate obtained assayed 0.41% U308 at a recovery of 95.3% and a ratio of concentration of 3.24. Previous investigations1,2 on the flotation of brannerite, pitchblende, uraninite and/or uranothorite from various Canadian ores showed that fatty acids, including oleic acid and tall oils, petroleum sulfo-nates and alkyl acid phosphates, were suitable collectors for these uranium minerals. Additional work carried out by the Mines Branch in Ottawa on brannerite ores from the Elliot Lake area3 used the tall oil Acintol FA-1, or FA-2, as a collector. A recovery of 92% of the uranium in a concentrate which contained about 55% of the weight and assayed 0.2% U3O8 was obtained from a feed of 0.1% U308 in this latter instance. Eigeles et a1.4 carried out flotation on pitchblende ores and found that the most promising results were obtained with alkyl acid phosphates and their alkali salts as collectors. Within the homologous series of alkyl phosphates, the best flotation characteristics were displayed by isooctyl phosphates. Further, isooctyl phosphate derivatives were much less sensitive to hardness forming salts than oleic acid, enabling all flotation tests to be made with tap water. This paper describes tests employing alkyl acid phosphates for the flotation of ores containing brannerite and uranothorite. The flotation work described herein was conducted in conjunction with the development of a leaching process for Elliot Lake, Ontario, brannerite ores. In this process pyrite in the ore was concentrated by flotation and roasted, providing sulfur dioxide which was used to produce sulfuric acid in situ in a liquid-solid extraction process. A 40% conversion to sulfuric acid was indicated at a leaching temperature of 80°C; this resulted in the extraction of 93% of the total uranium after a contact period of 6 hr. A rotary kiln was used as a leaching vessel. Preconcentration by flotation was studied in conjunction with the above process to reduce the bulk of solids for leaching and, consequently, capital expenditure. The materials and methods used in this study will be described initially. Then the results will be presented in two sections, the first dealing with the brannerite ore, and the second with the uranothorite. Finally an economic analysis of the results on the brannerite material will be made. MATERIALS AND METHODS The two ore samples examined were from uranium-producing mines. One was a brannerite ore, a uraniferous quartz pebble conglomerate from the Elliot Lake area, which contained 0.11% U3O8, 4.3% S and 4.5% total Fe. Mineralogical studies of similar samples indicated the presence of quartz, microcline, sericite, pyrite and minor quantities of rutile, pyrrho-tite and zircon. The other ore was from a biotite-rich pegmatite in the Bancroft area; feldspar, quartz and biotite formed the major gangue components. Uranothorite was the principal uranium mineral; the head assay was 0.13% U 3 O 8. Preparation of Feed: The ores were crushed to —10

Jan 1, 1963

By P. D. Merica, A. N. Finn, R. G. Waltenberg

CeRtain compositions of the light, i.e., aluminum-rich, alloys of aluminum with magnesium and copper have become quite well known within the past ten years under the name of duralumin. These alloys are used for rolling and forging and can be so treated as to develop quite remarkable mechanical properties. Thus a properly heat-treated alloy containing about 4 per cent. of copper and about 0.5 per cent. of magnesium, rolled into sheet or rod, will have a tensile strength of approximately 55,000 1b. per sq. in. (3866 kg. per sq. cm.) with an elongation in 2 in. (50.8 mm.) of about 15 per cent. This alloy, duralumin, was developed by Wilm,1 and its properties more fully described by Cohn.2, The authors considered it worth while to investigate the mechanical possibilities of the light alloys of two somewhat analogous ternary series; namely, of aluminum-magnesium-nickel and aluminum-magnesium-manganese, to study the effect of variation of composition upon mechanical properties within the alumimum-rich group of the aluminum-magne-

Jan 1, 1921

By Waldemar Dyrssen

I CANNOT agree with the results obtained by the committee. The gas obtained per pound of coal is too high in calorific value and the amount of gas is too large. It should require about 190 cu. ft. of oxygen per 1000 cu. ft. of gas and not 75.14 cu. ft. as is given on page 35 of the report, or about 2.5 as much. Calculating the calorific value per pound of coal from the coal analysis given on page 34, according to Dulong's formula, the gross and net calorific heat are about 12,890 and 12,430 B.t.u., respectively, which is about 18,600 and 17,900 B.t.u., respectively, per pound of carbon in the coal. This is an unusually high figure, as ordinary bituminous coal has less than 18,000 gross B.t.u. per pound of carbon. Assuming, however, that the calorific values calculated are correct, the following results are obtained. On page 35, the net calorific heat in the gas per pound of coal is given as 12,856 B.t.u. and calculation for the gross value shows it to be about 13,950; in other words, the gas contains (13,950 - 12,890) ÷ 12,890 = 8.2 per cent. more heat than the coal on a gross basis and (12,856 - 12,430) ÷ 12,430 = 3.4 per cent. more on a net basis. The calculated amount of carbon in this gas per pound of coal gasified is about 0.688 lb., or nearly the same as in the coal (0.6972) and the gross and net calorific heat per pound of carbon in the gas are 20,300 and 18,710 B.t.u. which are 9.1 and 4.5 per cent. more than for the carbon in the coal. These calculations show that the results given in the report cannot be correct. There must always be some heat losses in the gasification of coal, in radiation from the producer, and in sensible heat in the gas; there must be some loss of carbon in ashes and in soot, and there are always tarry vapors in the gases that are condensed and do not appear in the fixed gases. From the excessive heat in gas per pound of carbon contained therein, it can also be concluded that the percentage of hydrogen in the gas is too high, from which it follows that the moisture decomposed is too high and that more free oxygen must be used.

Jan 11, 1924

By R. S. Shoemaker, F. W. McQuiston

BENGUET EXPLORATION, Inc. Tuba, Benguet, Philippines 1970 Operating Data ORE DESCRIPTION: Complex ore mostly sulfides and composed mainly of sphalerite and pyrite with minor amounts of chalcopyrite, galena, arsenopyrite, hematite, magnetite, chlorite, calcite, garnet and quartz. TYPE OF MINE: Underground, cut and fill method ORE HAULAGE TO MILL: Mine rail cars with electric locomotives. CAPACITY in TONS/24 HRS: 130 ASSAYS: Mill Heads Mill Tails Au = 0.65 oz per ton Au = 0.096 oz per ton Cu = 0.75% CU = 0.27 % Zn = 10.50 % Zn = 0.64 % Ag = 3.20 oz per ton Ag = 0.33 oz per ton Cd = 0.01 % PRODUCT: Au, Ag, Cu, Zn and Cd RECOVERIES: = 90% ~g = 89% Cu = 60% Zn = 94% SCREEN ANALYSIS OF MILL FEED: 90% -200 mesh POWER: Grinding 25.4 Kwh/T Copper Flotation 14.5 Zinc Flotation 13.3 Cyanidation 20.4 Others 25.0 TOTAL POWER: 98.6 KwH/T WATER: Pumped from riverside and underground 50 to 100 meters distance. Consumption of about 700 gallons per ton of new water.

Jan 1, 1975

By R. Simon, D. J. Graue

This paper presents correlations for predicting the solu-lility, swelling and viscosity behavior of CO2-crude oil sys8i.m~. The correlations were developed from experimental data obtained by the authors. These data are also presented. The data were determined by measuring the properties of mixtures of CO, and nine different oils. Experiinental conditions covered a range of 100 to 250°F and pressures up to 2,300 psia. Properties predicted by the correlations have average deviations, expressed as per cent of experimental value, of 2 per cent for solubility, 0.5 per cent for swelling and 12 per cent for viscosity. INTRODUCTION Interest in CO2 injection as an oil recovery process has led to the development of performance prediction methods which can be applied to specific reservoirs.1 iS To use these performance prediction methods, it is necessary to know the solubility, swelling and viscosity properties of CO2-crude oil mixtures at reservoir conditions. Some information on these properties has appeared in the literature; however, this information did not cover the range of different oils and conditions needed to prepare generalized correlations for reservoir engineering purposes. Consequently, an experimental program was undertaken to collect the data needed. The data obtained and the correlations developed from the data are described in the following sections of this paper. SOLUBILITY OF CO2 IN CRUDE OILS CO2 solubility data in the literature come from six principal sources. The solubility prediction method of Welker and Dunlop3 is limited to 80F. The information in Ref. 4 is of two types: the first includes binary and ternary mixtures of CO, and light hydrocarbons (C1 to C6), and the second gives data for CO1 and heavy hydrocarbons for a temperature range of 40 to 90F. Ref. 5 contains a KCO2 chart for systems whose convergence pressure is 4,000 psia. The KCO2's are based mainly on CO2-natural gas mixtures. Poettmann's work covered CO2 solubility in one condensate and one crude oil6,7 Ja-coby and Rzasa measured CO? solubilities as a function of pressure and temperature for two natural gas-absorber oil mixtures and two natural gas-crude oil mixtures.'8 CO, concentration in these four systems was fixed at 5 mol per cent. The work reported in this paper extends CO, solubility data to a variety of different crude oil types in a temperature range from 110 to 250F and pressures up to 2,300 psia. The experimental procedure used by the authors to obtain the solubility data consisted of combining known amounts of pure CO, and crude oil in a visual cell at a fixed temperature and measuring the bubble point of the mixture. Measurements were made for a total of 40 different CO2-oil mixtures and the results are shown in Table 2. The mixtures included nine different oils (seven crude oils and two refined oils) whose properties are listed in Table 1. All nine oils had vapor pressures less than 1 atm at the experimental temperatures. Consequently, analysis of the bubble-point vapor showed a CO, concentration over 99 mol per cent. At no time during these experiments was a second, more dense, liquid phase observed. The solubility correlation which was developed from the data in Table 2 is presented in Figs. 1, 2 and 3. In these figures, solubility is expressed as xco2 the mol fraction of CO, in the CO2-oil mixture. Fig. 1 shows solubility as a function of CO2 fugacity6 and temperature. Fig. 2 shows the same solubility data expressed as a function of saturation pressure and temperature. The solubility shown in Figs. 1 and 2 is for an oil whose UOP characterization factor is 11.7. UOP characterization factors of crude oils can be determined from Ref. 10 if the viscosity and APT gravity of the oil are known. Fig. 3 gives the solubility correction factor for oils whose UOP characterization factors differ from 11.7. The solubility correlation in Figs. 1, 2 and 3 predicted

Jan 1, 1966

Jan 1, 1900

By G. T. Hahn, C. N. Reid, A. Gilbert

An evaluation is made of the possible cautsal relationship between twinning and fracture in molybdenum. For both single and poly crystalline material no instance of twin-induced fracture was observed. Instead brittle fracture was found to be slip-induced at heterogeneities. For single-crystal material, the yield stvess in compression and the fracture stvess in tensiow obey a similar angular- relationship which follows approximately a 1/cos2 ? law. where 0 is the angle between the specimen axis and the nearest (100) plane. This sittlilarity between yield and fracture behavior casts doubt on the interpretations made previoltsly that a 1/cos2? relationship supports a critical normal fracture stress criterion. SINCE fracture in brittle materials takes place at stresses an order of magnitude lower than the theoretical strength of the lattice, it must be postulated that some stress-concentrating effect is operative during the fracture-initiation process. Several mechanisms have been proposed whereby the necessary stress concentrations could be produced. The well-known Cottrell mechanism1 describes a dislocation interaction which can lead to the formation of an incipient cleavage crack on a cleavage plane, and both zener2 and stroh3 have discussed models which predict the stress concentration at the intersection of a slip band with a grain boundary. When twinning occurs twin/twin intersections and twin/grain boundary intersections represent another possible means of fracture initiation. Although still controversial, the concept of twin-induced fracture is supported by a weighty mass of evidence, which has been reviewed in a recent paper.4 This investigation was conducted in order to assess the extent to which the brittleness of molybdenum can be ascribed to this cause. Emphasis was placed on seeking direct metallographic evidence for twin-induced fracture such as arrangements of twins located at the fracture origin. EXPERIMENTAL PROGRAM Materials. The experimental materials are described inTable I. From the chemical analyses and estimates of the amounts of interstitials likely to be retained in solution,5 it is concluded that all were mul-tiphased systems. X-ray diffraction experiments6 showed no evidence of preferred orientation in the polycrystalline materials. Single crystals were grown from Molybdenum X and Y using the floating-zone technique,' in a vacuum of better than 3 x 10-5 Torr. However difficulties were experienced with Molybdenum X due to violent gas evolution from the molten zone, and additional crystals (Crystals 3 to 6) were produced by annealing for 5 1/2 hr at 2300°C under a vacuum of 10-4 Torr. Techniques. A series of tension, compression, and bend tests was conducted. Tension tests were used to demonstrate brittle behavior, to measure brittle-fracture stresses, and to provide fractured specimens for metallographic inspection. Compression tests were employed in order to obtain some ductility and a measure of the yield stress. Furthermore, it was considered that compression loading would permit the study of crack nucleation in the absence of propagation. The bend tests were conducted to facilitate identification of the fracture origin, which would be expected to be at, or near, the tensile surface of the sample. Tests were carried out at temperatures between 78" and 298°K attained by means of a liquid-nitrogen evaporator of modified Wessel design.' Specimens were fashioned by mechanical grinding, and, prior to heat treatment, were electropolished at 10 v in a 3:l mixture of ethyl alcohol and sulfuric acid, using a stainless-steel cathode. Except where noted, a strain rate of 4 pct per min was used. All specimens had a gage section 0.75 in. long; diameters of 0.10 and 0.20 in. were adopted for the tension and compression specimens, respectively, the former of single shoulder design, the ends being gripped in split collets with a conical bearing surface. In the bend test, electropolished specimens measuring 0.080 by 0.25 by 1.25 in. were deformed at 78°K by four-point loading. The bending device had spans of 1 in. between the outer and 4 in between the inner fulcra; it was stressed between the compression anvils of the Instron machine at a constant deflection rate. EXPERIMENTAL RESULTS Polycrystals. Tension and Compression Tcsls. It is apparent from Fig. 1(a) that above 170°K fracture of Molybdenum X takes place at stresses equal to or greater than the compressive yield stress whereas

Jan 1, 1967

Prof. Henry M. Howe, New York, N. Y. (communication to the Secretary*):—The results presented in Mr. Mathewson's paper are of very great interest. Perhaps the most interesting is that shown in Table I. and Fig. 1, in which the arsenic decreases in 10 min. from 0.22 to 0.07 per cent. This is such a large decrease that it is to be hoped that Mr. Mathewson will verify it by repeating his tests with a matte of similar composition. This is particularly to be desired, because the simultaneous removal of sulphur appears to be very small. All three blows further agree in showing that the removal of arsenic is in the very early part of the blow. The fact that the removal of arsenic then ceases abruptly cannot be explained completely by the fact that the arsenic has fallen so low as by its lowness to resist further removal, because in the first blow the arsenic becomes stationary at 0.06 per cent., whereas in the third blow it does not become stationary until it has fallen to 0.034 per cent. The abrupt ending of the removal of arsenic is more likely to find its explanation in the composition of the slag, and it is to be hoped that Mr. Mathewson will supplement these extremely valuable data with others in which the composition of the slag at the same time shall be given. The sudden rise of arsenic toward the end of the third blow I suppose must be referred to an error in sampling or analysis.

Jan 1, 1908

Jan 1, 1965

Jan 1, 1951

Jan 1, 1951

By Persifor Frazer

The section along the left bank of the Susquehanna, in Lancaster County, from Falmouth to the Maryland line, which the writer made in 1877 to accompany his report on that county, was redrawn by Professor Lesley, as stated in the prefatory'letter to Vol. CCC. (p. x.).* As then stated, neither the numerous data, nor the general features of the structure obtained by the writer, were changed ; but enough was done to make a discrepancy between the text and the section as given; and some important points were made less clear in the published section than they were in the MS. map. Amongst other portions of the section, that between the railroad stations, 1190 to 1224, gives the impression on the published maps of a much too definite superposition. A few words will be devoted to this region in the following communication. There is absolutely no room to doubt the structure for about four miles on .each side of the Tocquan axis. The dips are gentle, and in opposite directions, and the lithological characters constant within ordinary limits of variation, nor do these characters resemble those of the rocks which flank these gneisses and mica schists to the northwest and the southeast. For the same reasons it is evident that the rocks which occur within these eight miles or so, represent an horizon below the basement of the fossiliferous or palaezoic series. Not only have no fossils been found, but their lithologieal characters are unmistakably eozeic. But on the upper and lower margins of this

Jan 1, 1884

By M. E. Wadsworth, A. S. Peck

Infrared spectra disclose that oleic acid will not adsorb on the surface of pure beryl unless the mineral is first activated with HF. The adsorption of oleic acid on HF activated beryl is attributed to the hydrogen bonding of oleic acid monomers to F-surface bridging sites. These sites are formed as a result of the reaction of HF with chemisorbed water or surface hydroxyl. Characteristic infrared spectra of physically adsorbed oleic acid are correlated with flotation at different pH at temperatures of 25°C and 75°C for colloidal and -60-mesh particles. The usual mode of occurrence of the beryllium mineral beryl, Be3A12Si6O18, is in granite pegmatites as pale green, white, or yellow crystals. A dark green gem variety, emerald, may be found in the wall rock of pegmatite veins or in mica schist. The most important beryl deposits in the United States are in the Black Hills District of South Dakota, and several mountain ranges of central and west-central Utah contain potential commercial sources of this mineral. Several papers have been published concerning the flotation of beryl with different conditioning reagents. Kennedy and O'Meara1 reported on the essential use of HF in the flotation of beryl from different ores. The use of calcium hypochlorite to separate HF activated beryl from feldspar after flotation with an amine collector was made by Runke.2 A report on the activation of beryl with different cations using sodium oleate collector was presented by Viswa-nathan and co-workers.3 Flotation of beryl with sulfonate collector and different activating salts was employed by Fuerstenau and Bhappu.4 The role of the surface charge or zeta potential in the flotation of beryl with different collectors and salts was also extensively investigated.5"7 Previous infrared investigations by the authors8 disclosed that the orthosilicate beryllium mineral, phenacite, reacts with oleic acid to form a chemisorbed oleate monolayer on the mineral surface. Thus, chemisorption is the effective mode of adsorption in the phenacite-oleate acid flotation system. In contrast, neither chemisorption or physical adsorption of oleic acid occur on the surface of pure beryl as evidenced in this study. Efforts were subsequently made to determine the mechanism of activation and collector adsorption for HF pretreated beryl. EXPERIMENTAL PROCEDURES Large, white, terminated crystals of beryl were obtained from Madagascar through Ward's Co., Monterey, Calif. The crystals were broken into -60-mesh fragments in a porcelain mortar. Part of this prepared material was ground to a powder with a Fisher Grinder using an agate mortar and pestle. The powder was transferred to a graduated cylinder and mixed with 500 ml of distilled water. After 5 min, the colloidal suspension was separated from the settled particles by decantation and used as a stock for infrared test determinations. Adsorption tests were performed by first transferring 20 ml of colloidal suspension to 50 ml glass centrifuge tubes. The solids were then centrifuged out and the liquid was discarded. Then, the solids were pretreated with one molar HC1 or one molar HF. After 15 min, the solids were again centrifuged out. The mineral solids were washed free of residual acid by repeated centrifuging and water washing operations. Then, 20 ml of distilled water was added to the solids, and the resultant suspension was used for test purposes. In the preparation of mineral for flotation tests, 1.5 g of -60-mesh beryl was deslimed by removing the colloidal fraction by three successive water washes and decantations. Then, the coarse particles were pretreated with either one molar HCl or one molar HF for 15 min. The mineral was next washed free of acid with distilled water, and 20 ml of distilled water was added to the beryl prior to collector conditioning. The conditioning of mineral with collector was performed in 50 ml centrifuge tubes to which either NaOH or HC1 was added for pH modification. One drop (6.0 mg) of U.S.P. reagent grade oleic acid or 2 ml of 0.01 molar sodium oleate was added to the pulp and stirred at about 1500 rpm for 3 min at a

Jan 1, 1968

By R. J. Wasilewski

The resistivity of single crystal and of polycrystalline metal has been determined between 77° and 1500°K. At comparable purity, the resistivity of the poly crystalline metal differs from that calculated from the axial resistivity values. The observed anisotropy is briefly discussed. A zone refined titanium rod was obtained from F. J. Darnell.1 The hardness of this material varied between 52 and 64 Bhn, indicative of its high purity. Single-crystal specimens were cut out from a few large grains, elongated predominantly along <1120>. Resistance measurements were taken with specimens immersed in liquid nitrogen, solid CO,, and acetone, and at ice point, and then recorded continuously between room temperature and 1200" to 1250°C, throughout at least one full heating and cooling cycle at a rate of l° to 3°C per min. Four probe measurements were taken using spot-welded Pt wire 0.003 in. in diam as potential terminals, and the electromotive force drop was determined poten-tiometrically. A standard resistance, in series with the specimen, served to determine the dc current (generally about 80 ma) in the circuit. In order to eliminate spurious thermal electromotive forces, the circuit polarity was automatically reversed at 5-min intervals, and the mean of the two adjacent readings taken as the true electromotive force value. The discrepancy between the readings at reversed polarities was generally of the order of a few µ v, as all the spot-welded joints were contained within a volume of some 5 mm cube. The relative resistance (R T/R 273o) variation with temperature is tabulated below, and shown in Fig. 1, as measured during the first heating run. The discontinuous drop in resistance, corresponding to the a — ß transformation, started for both initial orientations at 1170°K; i.e., some 15°K above the accepted value of 882°C (1155°K). Judging by the temperature ranse of transformation—some 30°K for the single crystal and 20°K for the polycrystal-line specimen—this difference is believed caused by the solution of the oxygen present initially on the surface of the specimens. The general trend of the resistance vs temperature shown in Fi,;. 1 is in qualitative agreement with that previously reported for polycrystalline titanium metal. 2,3 Significant anisotropy is, however, indicated by the crossing over of the curves for <1120> and <0001> orientations at 273°, 650°, and 1000°K. This difference is most startlingly shown in Fig. 2, where instantaneous temperature coefficients (l/R273 x dR /dT) are plotted for both the first heat-

Jan 1, 1962

By Fred E. Beasley

Metallurgists have, in the last ten years, overcome many difficulties of high zinc in lead blast-furnace slags. This problem was brought to the front at the close of the war, by the price obtained for lead and the high cost of labor, fuel, and flux. The Port Pirie plant of the Broken Hill Associated Smelters, Australia, early in 1919 had increased the zinc oxide in its blast-furnace slags from 13.5 to 20 per cent., at the same time reducing the iron oxide in the slag from 33.5 to 25.6 per cent. These results were obtained by the addition of 10 to 12 per cent. granulated slag to the roaster charge, improved conditions of the crushing, mixing, and roasting of the constituents of the sinter. By experiments and improvements, the practice at this plant has developed a normal slag that carries 22 per cent. zinc oxide, and at times runs as high as 33 per cent. zinc oxide, with only slight furnace trouble. The granulated slag is used not only as a diluent to the sulfur in the roaster charge, but on account of its value as a slag-forming material and the physical properties it imparts to the finished sinter. The ore is mixed with flux and given a double roast. All the first roasting is by sintering with the Dwight & Lloyd machines. The final roasting is performed partly by Dwight & Lloyd machines and partly by H. & H. pots. The charge to the blast furnace consists chiefly of the final sinter, slag shells, siliceous and non-bearing sulfur lead ores. High blast and ore columns are the practice. The greatest care is taken to obtain in the final sinter as low a sulfur content as possible. Attracted by the success of the Port Pirie plant, The Consolidated Mining & Smelting Co. of Canada, at Trail, B. C., in 1920 treated its crushed primary sinter with about 15 per cent. granulated slag. The Trail smelter at this time was short of ore and a large part of the charge to the roasters consisted of the zinc-plant residue having the following analysis: 12 to 16 per cent. lead, 12 to 16 per cent. zinc, and 25 to 30 per cent. iron. The lead in the final sinter was low and the physical condition was so bad that all the sinter had to be screened before it could be charged to the blast furnace. Also it disintegrated on being trammed and dumped

Jan 1, 1925

By George K. Foster, Charles D. Borror

THE Jeffrey mine of the Canadian Johns-Manville Co., Limited, is in the town of Asbestos, situated approximately 100 miles northeast of Montreal and about the same distance southwest of Quebec, in Richmond County, Quebec. Mining operations were started in 1881 on outcrops on a hill, as a side-hill cut, followed by a second and third cut. This development was the forerunner of the present large open-pit operations, the mine now ranking as the largest openpit asbestos mine in the world. Operations were first carried on by hand, then by horsepower and later by stem cableways. By 1924 the derrick spans, 2000 ft. or more long, became unwieldy. To overcome this, and also to eliminate hand labor as much as possible, steam shovels and railroad haulage were introduced. The steam shovels were replaced in 1928 by larger electric shovels of the full-revolving type. THE ORE BODY The ore body is a serpentinized peridotite rock mass. The chrysotile fibers form a network of veins throughout, varying from microscopic width to two or more inches measured across the veins (Fig. I). These veins may be continuous for a few or many feet; they may increase or decrease in width within a few feet. The veins in which the fibers occur perpendicular to the veins are known as cross fiber. Those in which the fibers lay parallel to the veins are known as slip fiber. The cross fibers are of better quality, and more in demand. The majority of the fiber [ ]

Jan 1, 1946

By C. R. St. John, R. W. Lindsay, Charles R. Austin

MANY of the factors influencing the creep behavior of ferrous alloys have been investigated and reported upon in the literature, including such variables as grain size, steelmaking practice, nature and stability of the microstructure, and the effect of alloying elements in steels. However, with respect to the latter, the microstructures involved are usually heterogeneous and as a result the effect of the addition is related to its effects on the various phases present in the microstructure. In the instances where this structure consists of ferrite and carbide, the behavior of the alloy addition will be related to its action in strengthening ferrite and in opposing temperature softening of ferrite as well as coalescence of carbide. The present paper is the third in a series comprising a comprehensive review of investigations on the properties of iron binary alloys. 1.2 Its purpose is to describe the results of isolating one microstructural phase, namely ferrite, and studying its creep characteristics in both the unalloyed and alloyed conditions. This should aid in establishing to a large degree the importance of ferrite in the creep behavior of steels consisting of the previously mentioned ferrite-carbide aggregate. REVIEW OF PREVIOUS WORK In view of the fact that the present investigation deals only with the effects of silicon, manganese, chromium, molybdenum, nickel, and cobalt, and to a certain extent with the effects of carbon, the review of previous literature will be confined to these elements. Practically no references were encountered dealing with the influence of these elements on the creep characteristics of the isolated phase. However, various contributions have dealt with the creep behavior of low-carbon steels alloyed with the elements under consideration. A particularly concise review in this respect is given by Bullens (Battelle)3 and much of this material has been drawn upon. The definite improvement in creep resistance and high-temperature strength conferred by molybdenum is well known. Published suggestions by the A.S.M.E.4 permit of an increase of some 2000 to 5000 lb. per sq. in. in permissible design loads over a temperature range from 650° to 1000°F. as a consequence of additions of 0.40 to o.60 per cent of this element in carbon steels of the order of o.25 to o.35 per cent carbon content. Babcock and Wilcox Tube Co.5 has published data showing the pronounced increase in stress necessary to cause one per cent creep per 10,000 hr. when additions of 0.5 or 1 per cent molybdenum are made to a plain carbon steel. These data apply to temperatures over a range from 800° to 1000°F.

Jan 1, 1945

By H. Bloom, H. E. Hawkes

STREAMS and rivers are the principal channels into which the weathering products of rocks and their contained ores are funneled. The inorganic load of a stream system is a crude sample of all the earth materials in the drainage basin of the stream, and the heavy mineral assemblage of sediments is one of the oldest and most successful guides to certain kinds of bedrock ore in unexplored terrain. Early application of this method was made possible by the ease of separation and identification of heavy minerals in the field with the simplest equipment. Water analysis for traces of base metals became a practical possibility about eight years ago with the development of rapid chemical tests that could be carried out at the field site.&apos; , Since that time the water method has been widely used in mineral reconnaissance, and a substantial number of discoveries have been reported. Here again, the techniques developed for this work were relatively simple and could be performed easily at the field site. Sediment analysis by chemical methods, as distinguished from mineralogical, has received less at- tention. Some experimental work was done by Lovering and others," but to the authors&apos; knowledge, chemical analysis of sediment samples has not been used in routine exploration programs until very recently. In spite of the obvious promise of this method, it was not pursued vigorously because of the lack of a simple and portable chemical test that could be used conveniently at the field site or in a field camp. Procedures that had been developed for trace analysis of soils all called for a rigorous chemical attack with hot acids—tests more conveniently applied in processing large volumes of routine soil samples at an established field headquarters. Recently an extremely rapid and simple test was developed by Bloom.4,5 The extractant used in this procedure is a cold solution of ammonium citrate. Elements measured are the heavy metals, principally zinc, lead, and copper. This method differs from the established procedures for soil analysis in that it measures only a small fraction, about 5 pct, of the total metal content of the sample. It has been found, however, that the significant pattern of metals in the sediments of streams below a base-metal deposit can be brought out as well and sometimes better by this simple cold-extraction procedure than by the more tedious methods requiring hot acids. To understand fully the significance of the relation between the readily extractable and the total

Jan 1, 1957