Search Documents

By M. E. Hassan, J. C. Calhoun, R. F. Nielson

An apparatus was constructed for the measurement of inter-facial tensions over a range of temperatures and pressures. This apparatus utilized the pendent drop method, and resembles in construction similar apparatus recently described in the literature and in use in some petroleum research laboratories. The interfacial tensions of benzene, propane, n-pentane, n-hexane. n-octane. and iso-octane against water were measured at temperatures ranging from 26" to 82" C and at pressures ranging from 1 to 204 atm. Values of interfacial tensions for the henzene-water system and their variations with temperature and pressure are generally in good agreement with value? of previous investigations. The data in all cases showed a slight decrease of interfacial tension with pressure at constant temperature in the range studied. The effect of pressure became less as the pressure was increased, with an indication of a reversal of the effect at higher pressures. There was a decrease of interfacial tension with temperature at constant pressure in all cases, as would normally be expected. This rate of decrease became greater the higher the temperature. A general equation is presented for the interfacial tensions as a function of presPurp and temperature over the range studied, and the constants calculated for each system. A definite trend was found in the effect of molecular weight on the interfacial tension at a given temperature and pressure, for the homologous series from propane to n-octane. Data for n-decane from the literature fitted well into this trend. INTRODUCTION It has been recognized for many years that surface forces play an active part in the production history of an oil reservoir as well as in determining the amount of unrecoverable oil. The magnitudes of these forces are governed by the values of the interfacial tensions. These vary greatly with composition, pressure, and temperature. The effect of composition is greater than that of pressure and temperature over the ranges normally encountered. In fact, because of the variety of compounds present in a crude, no attempt has yet been made to correlate crude composition with its surface tension or with its interfacial tension against water. The amount of dissolved methane greatly affects the surface properties of an oil, and there are "surface-active" compounds in crudes which have a much greater effect on boundary tensions than do equal amounts of hydrocarbons. The purpose of the present work was partly to contribute data that would eventually be used in correlations applicable

Jan 1, 1953

By T. T. Read

TWO papers on health and safety were given Thursday afternoon when a joint session of the Health and Safety Committee and the Mining Methods Committee was held. T. T. Read presided and the first paper, on ventilation at Climax, was presented by the author, L. H. Glanville. In the subsequent discussion by Cloyd M. Smith, P. B. Bucky, B. F. Tillson, D. F. Haley, J. L. G. Weysser, and others a number of interesting points not covered by the paper, which appears in full in the January Mining Technology, were brought out. Ventilation troubles in mines so often hinge on the air being too hot and damp that it was interesting to hear of one where it is frequently too cold and too dry.

Jan 1, 1943

The following list comprises the names of those persons who became members during the period May 10, 1916, to June 10, 1916: ARCHIBALD, JOHN CHRISTIE, Min. Engr., Supt. of Cyanide Plant, Guanajuato Reduction Mines, Guanajuato, Mex. BRUNEL, FRANK P., Cons. Min. Engr Mitchell & Brunel, Ajo, Ariz. CALVERT, WILLIAM ROBERT, Cons. Geol. ...225 Kearns Bldg., Salt Lake City, Utah. CHAMPION, J. R., Supt The Yak Mining, Milling & Tunnel Co., Leadville, Colo. CHARLES, LAVERN JOHN, Construction Engr., Elephant Butte Dam, Elephant Butte, N. M. CHASTEL, ANDRE, Min. Engr., Societe Miniere & Metallurgique de Penarroya, 12, Place Vendome, Paris, France. CHRISTIE, WALLACE H., Vice-Pres. and Mgr., Alt. Bert Gold Dredging Co., 604 Mission St., San Francisco, Cal. CLARK, RONALD ..Hardinge Conical Mill Co., 120 Broadway, New York, N. Y.

Jan 7, 1916

By J. R. Craig, T. N. Solberg, M. A. Linden

The central and southern Appalachian Mountains were the major sources of domestically produced gold throughout the first half of the 19th century and continue to yield gold today. Small amounts of gold were probably extracted by the Indians and the Spaniards but the first documented report of gold in the region was made by Thomas Jefferson who found, in the Rappahannock River of Virginia in 1782, a 1.8 kg (4 lb) lump of gold ore that yielded 26 g (0.85 oz). Gold was subsequently discovered in North Carolina between 1793 and 1799, in Virginia in 1806, in South Carolina in 1827, in Georgia in 1829, and in Alabama about 1830 (Becker, 1894-5; Pardee and Park, 1948). Production climbed to more than 933 kg/a (30,000 oz per year) between 1830 and 1852, but dropped sharply after the California gold rush in 1849 as experienced miners moved west in search of bigger and easier stakes. The Civil War briefly halted gold mining in the Appalachians, but production rose to an average of about 249 kg/a (8,000 oz per year) from 1865 until 1878 and to about 404 kg/a (13,000 oz per year) from 1881 until 1915 when it again fell to near nil (Pardee and Park, 1948). Minor resurgences occurred in the 1930s and 1940s. Although there has been no reported production in recent years, it is likely that "weekend panners" still remove hundreds of ounces from streams annually. The total reported production for the area through 1959 is more than 77 t (2.5 million oz). This paper reports some initial findings of a long-term project designed to investigate the mineralogy, chemistry, mode of occurrence, and petrology of gold occurrences in the Appalachians. The goal of the initial phase was to determine the compositional range of gold in the Appalachians as a step toward deciding if sufficient variations were present to allow the definition of "compositional signatures." The very few published data on gold fineness in the Appalachians are based on assays that commonly include gold and silver from several mineral species. Analyses in the present study were performed on individual grains of electrum using a spot size of 10 µm x 10 µm to 100 µm X 100 µm (394 X 394 micro in. to 3,940 X 3,940 micro in.), and thus reveal the true composition of the principal precious metal-bearing phase.

Jan 1, 1984

ALBERT Ladd Colby, who died suddenly of influenza at Torquay, England, on Apr. 30,1924, was born in New York City, on June 26,1860. He was educated in the public schools of New York, at the College of the City of New York, and received the degree of Ph. B. from the Columbia School of Mines in 1881. He continued his studies at Columbia, acting occasionally as assistant to Prof. C. F. Chandler, until 1883. For the next three years he was Assistant Professor of Chemistry in Lehigh University; then head chemist and metallurgical engineer of the Bethlehem Steel Co., at Bethlehem, Pa., occupying the latter position until 1903. As head chemist his active and inventive mind devised several improvements in apparatus for increasing the rapidity and accuracy of the analytical work; as metallurgical engineer, he was, from time to time, in charge of the blast-furnace, open-hearth, bessemer, and puddling departments; he had entire charge of the inspection, assignment, and economic use of all metallurgical materials, and he early gave his attention to the formulation of specifications for metallurgical materials—an activity in which he long held a distinguished part in this country, and as a representative of his own country in England and Europe. He also sewed as expert for his company in patent suits, again laying the foundation for valuable service later as a consulting engineer. In this latter capacity he was excelled by few, if any, contemporaries in the iron and steel industry. His mind was ingenious, thorough, clear, and keen, both in the preparation of evidence and its presentation to the Court. He very quickly appraised the value of evidence, or of an answer to a question, and knew how to secure the infermation, either from the available literature of any language, or by special researches or plant studies. In the executive control of literary research for patent purposes, his long training, infinite capacity for digging through long series of articles in English, German or French, and clear formulation of the vital subject matter for the guidance of assistants, made him invaluable. He was also an adept in collecting information on special branches of his profession. For example, when the science of metallography began to assume importance, he made the first really comprehensive bibliography covering the literature of all siderurgical countries; for the newly formed International Nickel Co. he gathered all the information extant on the subject of nickel steel, both in the literature and in the minds of experts in America and Europe. Two books testify to the thoroughness of his work in this capacity, vie.: "American Standard Specifications for Steel,"

Jan 1, 1924

By Robert H. Carpenter

Molybdenite mineralization occurs in the hood zone of the Questa mine aplite-porphyry intrusive, one of the three sil ica-rich intrusive5 occurring along the east-west trending Red River Trench that crosses the northerly trending Sangre de Cristo Mountains in north-central New Mexico. The Trench is located immediately north of the circular Gold Hill positive block between the Red River and Cabresto Creek drainages. The aplite-porphyry bodies intruded a mid-Tertiary volcanic section consisting of lower andesites, overlain by latites and rhyolites. They occur largely in the andesites and were emplaced mainly by metasomatism rather than by sloping. Hydrothermal alteration occurs both as blanket propylitization in the volcanics and sericitization and kaolinization in the porphyries and as halo-type alteration outward from veins and shear zones resulting in strong biotization in the volcanics and sericitization and kaolinization in the aplitic rocks. Mineralization consists of: ( 1) molybdenite- quartz veinlets; (2) banded molybdenite, quartz veins frequently with biotite and potash feldspar along the walls and occasionally with minor lead, zinc, and copper sulfides and with fluorite and carbonates when again reopened; ( 3) high grade molybdenite locally along shear zones; and ( 4) molybdenite paint along joint and fracture surfaces. The mineralization was associated with faulting that resulted from numerous periods of gravity adjustment along the Trench and was controlled by the major shear systems that trend northeast, east-west and north-south to northwest. Molybdenite has been well oxidized in nearsurface exposures to ferrimolybdite and the molybdenum-bearing ferric hydroxide, akaganeite. The oxidation of the abundant pyrite within the veins and shear zones and of the alteration pyrite in the volcanics resulted in a low pH environment under which the acid molybdate ion released by oxidation was fixed either in the ferrimolybdite or the akaganeite molecule in the veins and shear zones or in the soils. Little has been lost in the runoff.

Jan 1, 1968

By G. M. Ikeda, J. G. Sibakin

An investigation was carried out to determine the variables affecting the coiling temperature of strip in the 56-in. hot strip mill. After statistical treatment, equations have been derived to determine the temperature drop between mill and coiler for both full spray (top and bottom) and top spray only practices. The individual influences of each variable in the temperature drop were derived for both practices. Limitations of the present practices were shown and adjustments in cooling for increased rolling speeds were suggested. A method of estimating the required number of sprays, their spacing, pressure, etc., to achieve a desired temperature drop is developed. MAXIMUM finishing temperature of a hot strip mill is mainly determined by the rolling speed, gage, and the temperature of the bar entering the mill. This finishing temperature may be limited by the maximum admissible coiling temperature in cases when either the cooling facilities on the runout table are not adequate or, more generally, when the cooling capacity of the runout table and the production capacity of the continuous mill are out of balance. Some time ago, the balance between these two factors was not considered detrimental to production. Recently, a new drafting schedule was introduced which increased the production rate, the entry temperature, and hence the finishing temperature. Thus, the restriction of the maximum specified coiling temperature became an important factor for many of the thicker gages. An investigation of the factors determining the coiling temperature may be, therefore, of considerable importance. A brief description of the available equipment will be a useful illustration of the techniques and methods used for this investigation. The 56 in. continuous hot strip mill is composed of six 4-high stands each containing two 221/2-in. diam work rolls and two 45-in. diam back-up rolls. Either of the last two stands can be used as the finishing stand. Which stand is used is dependent on the total percentage of reduction to be taken over the whole train, i.e., on the entry thickness and the final gage. The characteristics of these last two stands are given in Table I. Table I. Operational Characteristics of Nos. 5 and 6 Stands No. .5 NO. 6 Maximum voltage GOO 600 Power, hp 30(10 W00 I normal, kilonmp 4.35 3.73 Rpm of motor and rolls ISO 15 0 ITS to 300 Spettl ot strip, fpm 333 6 to 376T.2 103) to 2062 The speed of the finishing stand varies with the amount of reduction, strip width, and the exit gage. Finishing speeds in general use for varying gages are shown in Table 11. These speeds may change with an increase or decrease in the entry temperature of the strip. Even though the maximum speed of No. 6 stand is shown as 2062 fpm, this has so far never been attained,

Jan 1, 1957

By G. R. Speich

A cellular precipitation reaction in which cells consisting of an Ni3Ti (DO24) phase and austenite are formed has been studied in an austenitic Fe-30 Ni-6 Ti alloy. The variation of the growth rate and interlamellar spacing of the Ni3Ti cells with temperature has been determined m the range 400" to 975°C; the interlamellar spacing is proportional to the degree of undercooling; the growth rate can be expressed by an equation of the form G = K?T)2 exp(-Q/RT). The habit of the Ni3Ti lamellae is (001)Ni3Ti (111)y;[010]Ni3T2 [010]y. An almost perfectly coherent interface is formed between Ni3Ti lamellae with this orientation rela -tionship and the intervening austenite. This first Ni3Ti cellular product is subsequently consumed by a second cellular reaction of much coarser spacing. CELLULAR precipitation reactions have been studied in copper-base,1,2 Au-Ni,3 pb-sn,4 and iron-base ferritic5,6 solid solutions, and this mode of precipitation has been treated theoretically by smith," Turnbull,8,9 cahn,10 and more recently by bohm.11 In the case of substitutional austenitic iron-base alloys little or no data are available, Cellular precipitation reactions are well known in austenitic nickel-base alloys12,13 but usually these reactions do not proceed to completion because of general precipitation occurring in the matrix, and they have not been studied in detail. Precipitation from an austenitic Fe-30 Ni-6 Ti alloy was studied as part of a larger investigation of the mechanisms of precipitation from substitutional iron-base alloys. This alloy, austenitic at high temperatures, decomposes at lower temperatures by a double cellular precipitation reaction. The first decomposition product consists of alternate lamellae of an Ni3Ti(DO24) phase and austenite. The reaction proceeds to completion, consuming all of the original austenite. This first cellular product is subsequently consumed by a second cellular reaction of much coarser spacing. The first cellular reaction was studied in detail by light and electron microscopy, hardness measurements, and by X-ray and electron diffraction. Interlamellar spacings and growth rates were measured during isothermal aging in the range 400" to 975°C. The orientation relationship between the Ni3Ti and austenite lamellae was determined and indicates that an almost perfectly coherent interface exists between the two phases. This first Ni3Ti cellular reaction is of particular interest because it occurs over such a wide temperature interval. This allows cellular growth rates and interlamellar spacing data to be obtained for much larger degrees of undercooling than reported hitherto. MATERIALS AND EXPERIMENTAL PROCEDURE The Fe-30 Ni-6 Ti alloy was prepared from electrolytic iron, Mond nickel shot, and sponge-purity titanium* by vacuum melting in a zirconia crucible

Jan 1, 1963

By E. O. Kirkendall

THE investigation reported herein was undertaken to obtain data to supplement those presented in an earlier paper,' particularly for longer times at a higher temperature. This information may further develop our knowledge of the mechanism of diffusion in substitutional solid solutions. Diffusion of solute atoms interstitially dissolved is not difficult to visualize; it can take place without much disturbance of the solvent atoms. The mechanism of diffusion of solute atoms substitutionally dissolved is not so easily understood. Many theories have been advanced. Rosenhain,2.3 Frenkel,4 Smekal,5 Langmuir,3,6 Steigman, Shockley and Nix,7 and Johnson8 all proposed theories to explain diffusion. Langmuir's proposed mechanism consisted of a simple cyclic interchange of atoms involving an interchange in lattice positions of four or more atoms. This mechanism, accepted by the author at the time of his previous publication,' and apparently quite generally accepted, required a net exchange in positions of both solute and solvent atoms in equal numbers. In other words, the rate of diffusion of the solvent and solute atoms would be the same. That this cyclic interchange in lattice positions of solute and solvent atoms in equal numbers is the only true mechanism of diffusion is denied by the evidence presented in this paper. EXPERIMENTAL PROCEDURE This modification of similar procedure1 will be outlined briefly. The method consisted of the following steps: I. A pure Muntz metal (60.6 per cent Cu, 0.1 per cent total impurities) that was almost all beta brass at 780°C. was chosen. 2. The brass was turned between centers in a lathe to a diameter of 0.5965 inches. 3. After the brass was cleaned, it was electroplated with pure copper to a diameter of about one inch. 4. The sample was heated slowly to 400°C. under reduced pressure and held at that temperature for 4 hr. to remove occluded gases. It was then cooled to room temperature. 5. The sample was heated to 780°C. ±3°C. and held at that temperature for different lengths of time; then quenched. Samples were cut off each time after quenching. Metallographic samples 34 in. thick were removed at I hr., 6 hr., 24 hr., 96 hr. and 701 hr. After 96 and 701 hr. samples of about I in. were removed for X-ray analysis. 6. The metallographic samples were polished on the cross section and photo-micrographs were taken. 7. The I-in. samples were polished and etched on both ends. With the aid of a microscope each was carefully mounted in a four-jaw chuck in a lathe, so that they could be accurately bored for an arbor. 8. Turnings were taken for each X-ray sample. After each set of turnings, the sample was heated in an oil bath for about 3a hr. at 300°C. It was then etched in 25

Jan 1, 1942

By H. A. Doerner, F. D. DeVaney, J.B. Clemmer

Production of magnesium metal in the United States during the past decade has increased from less than 600,000 lb. in 1928 to more than 4,800,000 lb. in 1938.1 The growing industry has stimulated interest in methods of production and in sources of raw material. All of the present domestic production is from brines. However, the availability of large tonnages of magnesite in the state of Washington, together with the possibility of cheap power, have created interest in the utilization of magnesite for the production of magnesium metal as well as for other purposes. Magnesite, the carbonate of magnesium (MgCO3), usually is associated with limestone (CaC03) and dolomite (MgCO3. CaC03). It occurs in crystalline and microcrystalline (sometimes termed amorphous) forms.2 The more common crystalline mineral is found in various shades of white, gray, yellow and brown, the colors being due to impurities, chiefly iron. Magnesite has a hardness of 3.5 to 4.5 and a specific gravity of 3.0 to 3.1. It forms rhombohedra1 crystals in the hexagonal system, having a vitreous, pearly luster. The quarries and mines of the Northwest Magnesite Co. near Chewelah, Wash., are large producers of magnesite for refractories. The deposits are extensive, some veins being hundreds of feet wide. The boundaries of the veins are indefinite, and the magnesite is interfingered with dolomite. Calcite, talc, serpentine, quartz and shale are disseminated through the deposits. The quality of the ore cannot be determined by appearance or by simple tests; chemical analysis is required. These features make it difficult to determine the boundaries or total quantity of workable ore.3 Only the higher-grade ores are mined, and a considerable proportion of the magnesite content is discarded by hand-sorting and log-washing methods. After calcining, the sorted product meets the specifications for usual refractory material, as it contains approximately 81 per cent MgO, 7 per cent SiO2, 6 per cent CaO and 6 per cent Fe203 + A1203. A sample of the reject material had the following analysis after calcining: 65.4 per cent MgO, 6.3 CaO, 21.1 SiO2 and 6.5 R2O3. The percentage reported as R2O3 includes compounds whose chlorides are acid-soluble but give precipitates in ammoniacal solution that are ignited and weighed. The more common constituents are Fe2O3, A1203 and TiO2. The sorted magnesite product is not the best grade. even for refractory purposes, and leaves much to be desired for a reduction process. The rejected material contains a large proportion of magnesite. It is apparent that an effective concentration method would yield a higher recovery and a better product. In general, the refractory grade is not suitably pure for other uses. Recent developments in the production of

Jan 1, 1943

By J. B. Clemmer, F. D. DeVaney, H. A. Doerner

Production of magnesium metal in the United States during the past decade has increased from less than 600,000 lb. in 1928 to more than 4,800,000 lb. in 1938.1 The growing industry has stimulated interest in methods of production and in sources of raw material. All of the present domestic production is from brines. However, the availability of large tonnages of magnesite in the state of Washington, together with the possibility of cheap power, have created interest in the utilization of magnesite for the production of magnesium metal as well as for other purposes. Magnesite, the carbonate of magnesium (MgCO3), usually is associated with limestone (CaC03) and dolomite (MgCO3. CaC03). It occurs in crystalline and microcrystalline (sometimes termed amorphous) forms.2 The more common crystalline mineral is found in various shades of white, gray, yellow and brown, the colors being due to impurities, chiefly iron. Magnesite has a hardness of 3.5 to 4.5 and a specific gravity of 3.0 to 3.1. It forms rhombohedra1 crystals in the hexagonal system, having a vitreous, pearly luster. The quarries and mines of the Northwest Magnesite Co. near Chewelah, Wash., are large producers of magnesite for refractories. The deposits are extensive, some veins being hundreds of feet wide. The boundaries of the veins are indefinite, and the magnesite is interfingered with dolomite. Calcite, talc, serpentine, quartz and shale are disseminated through the deposits. The quality of the ore cannot be determined by appearance or by simple tests; chemical analysis is required. These features make it difficult to determine the boundaries or total quantity of workable ore.3 Only the higher-grade ores are mined, and a considerable proportion of the magnesite content is discarded by hand-sorting and log-washing methods. After calcining, the sorted product meets the specifications for usual refractory material, as it contains approximately 81 per cent MgO, 7 per cent SiO2, 6 per cent CaO and 6 per cent Fe203 + A1203. A sample of the reject material had the following analysis after calcining: 65.4 per cent MgO, 6.3 CaO, 21.1 SiO2 and 6.5 R2O3. The percentage reported as R2O3 includes compounds whose chlorides are acid-soluble but give precipitates in ammoniacal solution that are ignited and weighed. The more common constituents are Fe2O3, A1203 and TiO2. The sorted magnesite product is not the best grade. even for refractory purposes, and leaves much to be desired for a reduction process. The rejected material contains a large proportion of magnesite. It is apparent that an effective concentration method would yield a higher recovery and a better product. In general, the refractory grade is not suitably pure for other uses. Recent developments in the production of

Jan 1, 1943

By M. J. Stewart, F. Weinberg

PREVIOUS investigations into convective flow in molten metals have examined systems in which the length-to-height ratio of the enclosure is large, usually using long graphite boats.''2 In normal castings this ratio is generally small and it is not possible to extrapolate the results of previous work to casting configurations. The present investigation was undertaken to examine liquid flow in systems of low length to height ratio. The apparatus used for the experiments is shown in Fig. 1. The molten zone of tin is contained in an aluminum mold of inside dimensions 6.4 by 6.4 by 0.31 cm. A heating block containing a resistance coil is attached to one end of the mold and a cooling block is attached to the other end. These are used to produce a wide range of temperature differences across the mold. The mold is contained in a stainless steel tank which is heated from the outside by resistance heaters to give the required operating temperature during the experiment. Temperature measurements in the molten tin are made with an iron-constantan thermocouple PT equal to 5 atm. The phase diagram derived by us was the same as that found by Krivsky and Schuhmann, except for a similar discrepancy in one boundary line representing the gas composition in equilibrium with SO a. The vapor pressures of the pure components can be neglected at 1700°K, 1 atm and 2500°K, 5 atm. There-fore, in these cases PT is essentially the total pres-sure in the system. This is valid for all the diagrams presented by Krivsky and Schuhmann except for the one at 2500°K and 0.01 atm, where the vapor pressure of silicon is comparable to PT.6 This work was supported in part by the American Iron and Steel Institute. 'C. E. Wicks and F. E. Block: Thermodynamic Properties of 65 Elements, U S. Bur Mines, Bull. No. 605, 1963. R. P. Elliott: Constitution of Binary Alloys, 1st supplementary, McGraw-Hill Book Co., New York, 1965. 3W. A. Krivsky and R. Schuhmann, Jr.: Trans. TMS-AIME, 1961, vol. 221, pp. 898-904. 4M. F. Ancey-Moret, M. Olette, and F. D. Richardson: Mem. Sci. Rev. Met., 1964, vol. 61, pp. 169-76. 5J . F. Elliott and M. Gleiser: Thermochemistry for Steelmaking, vol. 1. Addison-Wesley, Reading, Mass. 1960. 6 J.Drowart, G. De Maria, and M. G. Ingraham: J. Chem. Phys., 1958, vol. 29, p. 1015. probe of 0.4 mm diam inserted into the open top of the mold. Radioactive sn113, in the form of a small sphere, was gently lowered into the molten tin at point A in Fig. 1 THERMOCOUPLE> WATER ARGON END HEATER QUENCH ARGON Fig. 1—Apparatus for detecting liquid flow. Point A indicates position the tracer was introduced.

Jan 1, 1970

By E. O. Kirkendall

The investigation reported herein was undertaken to obtain data to supplement those presented in an earlier paper,l particularly for longer times at a higher temperature. This information may further develop our knowledge of the mechanism of diffusion in substitutional solid solutions. Diffusion of solute atoms interstitially dissolved is not difficult to visualize: it can take place without much disturbance of the solvent atoms. The mechanism of diffusion of solute atoms substitutionally dissolved is not so easily understood. Many theories have been advanced. Rosen-hain,2,3 Frenkel,4 Smekal,5 Langmuir,3,6 Steigman, Shockley and Nix,' and Johnson8 all proposed theories to explain diffusion. Langmuir's proposed mechanism consisted of a simple cyclic interchange of atoms involving an interchange in lattice positions of four or more atoms. This mechanism, accepted by the author at the time of his previous publication,1 and apparently quite generally accepted, required a net exchange in positions of both solute and solvent atoms in equal numbers. In other words, the rate of diffusion of the solvent and solute atoms would be the same. That this cyclic interchange in lattice positions of solute and solvent atoms in equal numbers is the only true mechanism of diffusion is denied by the evidence presented in this paper. Experimental Procedure This modification of similar procedure1 will be outlined briefly. The method consisted of the following steps: I. A pure Muntz metal (60.6 per cent Cu, 0.1 per cent total impurities) that was almost all beta brass at 780°C. was chosen. 2. The brass was turned between centers in a lathe to a diameter of 0.5965 inches. 3. After the brass was cleaned, it was electroplated with pure copper to a diameter of about one inch. 4. The sample was heated slowly to 400°C. under reduced pressure and held at that temperature for 4 hr. to remove occluded gases. It was then cooled to room temperature. 5. The sample was heated to 780°C. ± 3°C. and held at that temperature for different lengths of time; then quenched. Samples were cut off each time after quenching. Metallographic samples 1/4 in. thick were removed at I hr., 6 hr., 24 hr., 96 hr. and 701 hr. After 96 and 701 hr. samples of about I in. were removed for X-ray analysis. 6. The metallographic samples were polished on the cross section and photomicrographs were taken. 7. The I-in. samples were polished and etched on both ends. With the aid of a microscope each was carefully mounted in a four-jaw chuck in a lathe, so that they could be accurately bored for an arbor. 8. Turnings were taken for each X-ray sample. After each set of turnings, the sample was heated in an oil bath for about 1/2 hr. at 300°C. It was then etched in 25

Jan 1, 1942

By E. O. Kirkendall

The investigation reported herein was undertaken to obtain data to supplement those presented in an earlier paper,l particularly for longer times at a higher temperature. This information may further develop our knowledge of the mechanism of diffusion in substitutional solid solutions. Diffusion of solute atoms interstitially dissolved is not difficult to visualize: it can take place without much disturbance of the solvent atoms. The mechanism of diffusion of solute atoms substitutionally dissolved is not so easily understood. Many theories have been advanced. Rosen-hain,2,3 Frenkel,4 Smekal,5 Langmuir,3,6 Steigman, Shockley and Nix,' and Johnson8 all proposed theories to explain diffusion. Langmuir's proposed mechanism consisted of a simple cyclic interchange of atoms involving an interchange in lattice positions of four or more atoms. This mechanism, accepted by the author at the time of his previous publication,1 and apparently quite generally accepted, required a net exchange in positions of both solute and solvent atoms in equal numbers. In other words, the rate of diffusion of the solvent and solute atoms would be the same. That this cyclic interchange in lattice positions of solute and solvent atoms in equal numbers is the only true mechanism of diffusion is denied by the evidence presented in this paper. Experimental Procedure This modification of similar procedure1 will be outlined briefly. The method consisted of the following steps: I. A pure Muntz metal (60.6 per cent Cu, 0.1 per cent total impurities) that was almost all beta brass at 780°C. was chosen. 2. The brass was turned between centers in a lathe to a diameter of 0.5965 inches. 3. After the brass was cleaned, it was electroplated with pure copper to a diameter of about one inch. 4. The sample was heated slowly to 400°C. under reduced pressure and held at that temperature for 4 hr. to remove occluded gases. It was then cooled to room temperature. 5. The sample was heated to 780°C. ± 3°C. and held at that temperature for different lengths of time; then quenched. Samples were cut off each time after quenching. Metallographic samples 1/4 in. thick were removed at I hr., 6 hr., 24 hr., 96 hr. and 701 hr. After 96 and 701 hr. samples of about I in. were removed for X-ray analysis. 6. The metallographic samples were polished on the cross section and photomicrographs were taken. 7. The I-in. samples were polished and etched on both ends. With the aid of a microscope each was carefully mounted in a four-jaw chuck in a lathe, so that they could be accurately bored for an arbor. 8. Turnings were taken for each X-ray sample. After each set of turnings, the sample was heated in an oil bath for about 1/2 hr. at 300°C. It was then etched in 25

Jan 1, 1942

By R. A. Nadler and

Specimens of Ti-155A (Ti-5Al-1.3Fe-1.3Cr-1.2Mo), Ti-6Al-4V and Ti-4Al-3Mo-1V were hydrogenated, aged to high strength levels, and subjected to notched stress-rupture tests and tensile tests at two strain rates. Both Ti-6Al-4V and Ti-155A were relatively unaffected by hydrogen in amounts exceeding those found in commercially -produced material. Inconsistencies in the data and a relatively low initial level of ductility prevented an accurate determination of the hydrogen tolerance for aged Ti-4Al-3Mo-1V, but there was no evidence that this alloy was any more susceptible to hydrogen embrittlement than Ti-155A and Ti-6A1-4V. THE metallurgical literature has been considerably enriched in the past five years by the publication of the results of many investigations which were concerned with the effects of hydrogen on titanium and its alloys. Although it is not the authors' intention to provide a complete literature survey of this vast field, it is worthwhile to summarize briefly some of the important factors which influence the embrittling phenomenon in a - B alloys. Some of the influencing factors are those of strain rate, temperature, and composition. Hydrogen embrittlement in a - B titanium alloys is now believed to be a strain-induced phenomenon, and whether or not embrittlement occurs at high hydrogen levels depends largely upon whether sufficient time is available for hydride precipitation. This condition is fulfilled by tensile testing at very slow strain rates or by rupture testing smooth or, preferably, notched specimens over relatively long periods. Conveniently, maximum embrittlement occurs at or near room temperature. The presence B - stabilizing elements, in amounts sufficiently small to prevent an all -B or nearly all -P condition, promotes hydrogen embrittlement and this tendency is believed to be related to the amount of a - B interfacial area present. Aluminum, by increasing the solubility of hydrogen in A titanium, greatly reduces the danger of hydrogen embrittlement, while oxygen has been shown to have detrimental effects.' The preceding discussion is based on experimental work performed on annealed a - P alloys. This early work has shown that annealed Ti-6A1-4V and Ti-155A are relatively insensitive to the embrittling effects of hydrogen.' Although no work has been reported on annealed Ti-4A1-3Mo-lV, the alloy would be expected to exhibit somewhat the same insensitiv-ity as Ti-155A. In sharp contrast to the voluminous literature on annealed titanium alloys is the paucity of reported investigations on materials receiving commercial heat-treatment cycles. To date, the most notable contributions in this field have arisen from two separate investigations on Ti-3Mn-1Fe-1Cr-1V-lMo, the so-called 3Mn comple~. These investigations

Jan 1, 1961

The Palabora ore consists of two types, a carbonatite containing a low titanium magnetite, and a foskorite containing high titanium magnetite. The latter type also contains substantial quantities of phosphate. These two ore types are separately crushed and are kept separate through copper flotation and magnetic separation, for recovery of magnetite, with the low Ti magnetite being shipped as iron ore. High phosphate tailings are pumped to Foskor, a government-owned phosphate plant nearby. The Palabora plant was originally designed in 1966 for 33, 000 tpd using two 54 in. by 74 in. Allis -Chalmers gyratories; two 7 ft (2. 13 m) standards; four 7 ft shortheads; and six grinding lines, each using one 1,200 hp rod mill and two 1,200 hp ball mills. A fifth short- head and one more grinding line were added later; and with flowsheet improvements, the capacity of the plant was increased to 59, 500 stpd. A further plant expansion involving a third 54 in. primary and two 32 ft by 15 ft (9.75 by 4.6 m) 9,000 hp autogenous mills and another flotation section will bring its capacity to 87,500 stpd in 1977. These two fully autogenous mills are constructed entirely out of doors near the primary crusher, and the ground ore will be pumped a mile to the concentrator by a five-stage pumping system. The Palabora ore is mined with 6, 10, and 12 7d (4.6, 7.6, and 9. 2 cu m) shovels and hauled to the crushers in 110 and 165 st trucks. Sixty-five ton trucks were originally used, but the crusher dump pockets were designed for larger units. Dump pockets, crushers, feeders, and take- away belts are offset in order to keep the two ore types separate. Centerlines of the crushers are only 43 ft (13. 1 m) apart; but, because of their being offset, maintenance room is ample. Initially, more carbonatite ore than foskorite was mined; but as the pit has deepened, this ratio has been reversed. The Palabora ore breaks in the pit with a large amount of oversize boulders; and, with the use of larger trucks, a splitter has been installed on one side of each dump pocket to protect the crusher spider. Smaller trucks dump on the opposite side. To accomodate the splitter, the pocket edge has been raised one meter and moved back one meter. Dust is collected through a special vent shaft between the crushers and the mantle relining area; but even so, two high-pressure water spray headers with nozzles are installed under the edge of the pocket at each dumping position. While only one truck dumps at a time, sprays from all four headers are used to suppress dust. Any leakage of water through the seal around the upper bowl of the crusher is caught by a circular trough under the seal and directed to a sump pump. At this point, there

Jan 1, 1978

SULPHUR is a very well known mineral and apparently is produced in many places. It is engendered from an unctuous earthy and powerfully hot substance so that it is considered among experienced workers to bear a resemblance to the element of fire. This is called by these same men the masculine seed and the prime agent of Nature in the composition of metals. Because of its great dryness and heat it has, as experience shows, affinity with fire, which is easily introduced in it when brought near. And once introduced the fire is quenched only with difficulty before its unctuousness is wholly consumed. Although it shows itself to us of such a hot and dry nature, we must not think that sulphur is a substance so pure that it can stand by itself or that in order to attain its form it has no need of its portion and part of moisture like every other mixture. This is shown to us by its easy fusion, in which it resembles the metals. This thing is found in many places and in many varieties of color; some are white, others yellow and orange, and some others between gray and black. They also say that some red is found. It does not occur in that arrangement of veins like other minerals, but most liberal Nature makes whole mountains of it as is seen in the Aeolian islands, [26] near Sicily, in Etna or Moncibello which is the island of Sicily, at Pozzuoli, in the territory of Rome, in the Sienese domain at San Filippo, and in many other similar places. It is a substance that has a very strong odor and is most unpleasant to smell. It is very fixed in its substance so that it is never corrupted by time, by boiling, or by the moisture of water. For although it may stand in water a long time it never becomes soft nor does it ever decrease or increase in weight. It is brittle and easily crushed very fine. It is said that a trace of garlic rubbed on the mortar helps anyone who wishes to reduce it to impalpability. Its ores have a form more like earth than like stone although they some¬times have the color of a certain soft rock. The places where it is found are easily recognized by the great odor that they give out and by the very hot baths that often spring forth near it. What I have already told you about quicksilver that is contrary to the

Jan 1, 1942

By J. W. Schroeder

SEAMLESS pipe, the product produced from piercing a solid round billet of steel by the Mannesmann process, was first produced in the latter half of the 19th century, the Mannesmann machine having been patented in 1885. The products of other processes also have been termed seamless pipe; for example, the cylindrical section produced by "cupping," which consists of forming a cup from a flat plate or disk and further elongating the cup into a tube by passing it through a set of reducing dies. The purpose of this paper is to discuss some of the more important metallurgical factors and their relationship to the economical production of seamless pipe produced by the Mannesmann piercing process. The first seamless tube plant in America was established at Shelby, Ohio, in 1891, and was employed in the manufacture of bicycle tubing. For a number of years the bicycle industry was the only user of seamless tubing, and this tubing was produced by hot-rolling pierced billets imported from Europe and finishing on the cold drawbench. At the turn of the century, the automotive industry was responsible for an increase in the demand for seamless tubing. The growth of this industry was the dominant factor leading to the phenomenal growth of the petroleum industry, which in turn created a tremendous demand for seamless pipe. In addition; the old lapweld iron boiler tubes for stationary and locomotive boilers were replaced gradually by seamless tubes. Since 1929, the production of seamless steel pipe and tubes has increased over loo pct. In 1929, 1,459,9031 net tons of seamless pipe was produced, including both hot-finished and cold-drawn material, as compared with 3,087,3122 net [ ] tons in 1948. Table I gives the distribution of seamless pipe by classes for 1948. METALLURGICAL PROBLEMS From a metallurgical standpoint, the production of seamless pipe has presented many problems. Practically every type of steel, carbon and alloy, with the exception of the superalloys developed during World War II, has been pierced and rolled successfully into tubing. This includes bessemer, open hearth, by the stationary and duplex processes, and electric steels. The range of sizes produced is no less staggering to the imagination, when it is considered that the hypodermic needle, which is 0.016 in. diam with a wall thickness of 0.004 in., and pipe for gas or oil transmission lines, with a 26 in. OD, are both seamless tubes. Between these extremes, the range of diameters and wall thicknesses meets most present-day demands for seam-

Jan 1, 1951

By N. LILIENBERGS

DURING the past few years, the requirements for steel have been raised so high that soundness is more important than ever before. The old practice was to mike steel ingots of sufficiently large sections to permit a considerable reduction of area in rolling and hammering to a given size, relying on the fact that by such rolling and hammering all cavities will be squeezed together and practically eliminated. The finished sizes, if found by inspection of the surface to be faultless, were therefore pronounced to be sound. But when such steel is ?worked up,? the manufacturer is surprised and disappointed to find that it splits, or that streaks and seams make the product unmarketable. Large sections, such as rails, beams or heavy forgings, may, within certain limits, be sufficiently strong, even if the sides of the cavities are only squeezed, and not welded together. But it is well known that, in the interior of heavy articles, under certain conditions, forging may develop small streaks into large cavities. Small sections, steel for ordnance and tubes, and numberless articles in the tool-trade, always show up the defects. It may be doubted whether cavities in steel ingots can ever be completely welded. The old theory, is, that the silver-clear blow-holes, without the blue oxide, can be welded by sufficient working. They are, however, not empty, but are filled with carbonic oxide. It is admitted that the "blue" cavities, resulting from air mechanically drawn down into the mold during the casting, can never be welded, because the oxide does not melt, and there would be no escape for it if it did. The only way in which steel can be made satisfactory for the above-named particular purposes is by having it ?dead molten." But then the trouble of piping is encountered. As is well known, a pipe is the result of the contraction of

May 1, 1906

By D. H. Newland

New York has a small but not insignificant place in the oil and natural gas industries of the United States. It has had a continuous record as an oil producer since 1872, with an aggregate yield of about 104,000,000 bbl. The reported output for 1935 was 4,237,000 bbl., a gain of more than 10 per cent for the year and a total that has been exceeded only in the early period of flush production half a century ago. The industry has been steadily building up since 1920 with the successful practice of the water drive, which has given a new lease of life to pools that had been practically drained of oil recoverable by pumping. An additional output of 2000 bbl. or more per acre is being procured by this method. Altogether the fields in New York State cover about 55,000 acres. Their limits are well defined and it is unlikely that they will be extended in the future, although there is some prospect of finding additional supplies by deeper drilling. The oil from New York is all classed as Pennsylvania grade, for which the recent price has been about $2.50 a barrel. It is refined at Olean, Wellsville and Bolivar, in the oil district, and partly in Pennsylvania refineries. Exploration for natural gas, outside of the established districts, was considerable during the year. Altogether 59 wells were drilled, distributed over 13 counties, of which 33 were listed as producers and 26 were dry. At the close of the year, 13 wells were in process of drilling. The 33 producing wells had a combined estimated flow of 278 million cubic feet per day. The best results were obtained from exploration in Allegany County, where out of eight wells drilled to the Oriskany sandstone five were successful and showed a combined open-flow capacity of 107 million cubic feet. The Oriskany sandstone was encountered at a depth of 4500 to 4900 ft. In Steuben County, next east of Allegany County, two out of seven wells to the Oriskany proved productive, and one of these, in the town of Greenwood, on the Watkins structure, was probably the largest that has so far been opened in the state, with a reported yield of 35 million a day. In the central part of New York interest was awakened by the activity shown in exploring for gas in the Trenton limestone, in Camden, Florence and Rome townships, Oneida

Jan 1, 1936