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By Jesse O. Betterton

In the Parkes process of lead refining, after desilverization has been completed by means of zinc additions, there will remain in the lead from 0.5 to 0.6 per cent zinc. At this stage in the refining practically all impurities are reduced to refined lead specifications except zinc and antimony. All excess of copper and nearly all the arsenic goes out with the silver. Silver remaining should not exceed 0.1 oz. per ton. It thus remains only to remove zinc and antimony to produce refined lead. The older practice was to complete refining by means of oxidation processes in reverberatory furnaces. Essentially this consisted of heating the lead to 1200' to 1300" I?. and allowing it to come in contact with a considerable excess of air passing through the furnace, or accomplish the same result by blowing the lead with steam by means of pipes introduced for that purpose, at the same time allowing air to enter the furnace. Usually some procedure involving alternate oxidation and reduction with fine coal or coke was employed in order to reduce the weight of dross or skim finally removed from the furnace. This practice had many elements of weakness in that the main flour of lead, after the preceding expensive operations had been performed, and the whole refining process nearly completed, was subjected to an operation at a comparatively high temperature, which involved much lead loss if the furnaces were not on bags, and the production of 3 to 5 per cent of the weight of the lead as dross or skim, which had to be resmelted and the lead either refined or produced as antimonial lead. In addition, the operating expense of the process was a considerable item. The process of dezincing with chlorine was developed as a substitute for the foregoing described oxidation process, and finally resulted in such advantages as nearly equal operating costs, a practical elimination of the lead loss, and the direct production of a very valuable byproduct, zinc chloride, that may be sold as such or retreated for its zinc and chlorine contents, both of which can be reused in the refining processes. Essentially this process consists of circulating the lead by means of a pump in a kettle through a closed reaction cylinder, gaseous chlorine entering the reaction cylinder with the stream of lead from the pump. Molten zinc chloride is thus produced and is discharged together with

Jan 1, 1937

By Harry W. Antes

The density changes that occurred on annealing cold-worked poly crystalline molybdenum, over the temperature range of 870" to 1630 SC, were determined. Increases in density were observed for recovery and the beginning of recrystallization. An initial decrease in density was observed during re-crystallization. A second decrease in density was observed after recrystallization was completed, as the microstructure changed from columnar grains to equiaxed gvains Both decreases in density were associated with an increase in gain boundary area to volume ratio. The second decrease in density was observed in the annealing range that immediately precedes secondary recrystallization as reported in the literature VARIOUS techniques have been used to identify the recovery, recrystallization, and grain growth processes that occur when cold-worked metals are annealed. As early as 1928 work was conducted that indicated measurable density changes occur when cold-worked single crystals of brass are annealed.' More recently, work by Murphy exhibited a corre- lation of density with microstructural changes observed on annealing cold-worked polycrystalline a brass.2 Other investigators have performed similar work on a brass and copper.324 In reviewing the literature, it was apparent that density work had been limited to fcc materials. Therefore, it was the purpose of this investigation to determine the density changes that accompany annealing the cold-worked bcc material, molybdenum. Two degrees of cold work, 30 and 90 pct reduction of cross-sectional area by rolling, were selected for this study. EXPERIMENTAL PROCEDURE High-purity vacuum arc-cast molybdenum was used in this study, the principal impurity being carbon in the amount of 80 ppm. The final rolling reductions were made at 1200°C in grooved rolls to provide 5/8-in.-diam rod. Density specimens 0.500 in. diam by 1.5 in. long were machined from the bar stock. The specimens were ground to the final dimensions to provide a smooth surface. Density measurements were made using a hydrostatic technique similar to that used by ~urphy.' This type of equipment permitted weighing in liquid immediately after the air weighing. During each weighing the temperature of the air and liquid was controlled to within 0.0l°C. This was accomplished by sealing the analytical balance in an air-tight brass chamber and surrounding it by an insulated wooden case. Preheated air was circulated in the air space between the brass chamber and wooden case by means of a blower. The temperature of the

Jan 1, 1964

By Raymond Mancha

TO determine the optimum inside dimension of an airshaft, it is necessary to strike the proper balance between the cost of power for air friction and turbulence losses within the airshaft, on the one hand, and the cost of sinking the airshaft, on the other. An airshaft larger than necessary is extravagant because the increased amortization rate exceeds the reduction in power cost. Conversely, an airshaft smaller than is needed wastes more power than can be justified by the corresponding reduction in amortization rate. The airshaft power is a function of the air volume Q cu. ft. per min. and the air-pressure drop p in. water gauge across the airshaft. † The airshaft pressure drop is calculated by the formula: R X l X O X Q2 P= 5-2 X A3 wherein R is the air-friction coefficient for the portion of the airshaft 1 ft. deep, 0 ft. in perimeter and A sq. ft. in area, when passing an air volume of Q cu. ft. per minute. The airpower w kw. dissipated within the airshaft is computed by the formula: w= 0.746Q X P 6345 With a combined over-all unit efficiency of the fan and drive of E per cent, the air-shaft power requirements become W = 100w There are 8760 hours per year, so with energy at I cent per kilowatt-hour the annual cost per kilowatt for continuous operation is $87.60; therefore, with energy at C¢ per kw-hr. the annual airshaft power cost MI dollars per year becomes: M1 = 87.60W X C which, expressed by the component parts, becomes: M1 V 5.2X4' / XQ Z 0.746 X 100 X 87.60 X C V 60 X E ) The amortization rate a dollars per year per dollar invested includes both depreciation and interest on the investment. These in turn involve the expected useful life of the airshaft and available molletary interest rate. For the purpose of this discussion the cost of airshaft sinking is assumed to comprise a fixed move-in charge Y dollars, which covers the cost of transporting, erecting and removing the shaft-sinking equipment and is independent of the air-shaft size. Also, it is assumed that the cost of shaft lining, if any, is fixed at $X per cu. yd. of lining material and that excava-

Jan 1, 1947

By G. H. Alvey, A. W. Foster

The measure of value of an oil property is approximated by the length of time it takes to "pay out;" viz., the time required for it to return the original investment. This time varies in different fields. In the Appalachian and Mid-Continent fields, a good investment pays out in about four years; in California, it requires a slightly longer time; and in the Gulf field about two years. The two principal methods for establishing these values are based on acreage, as in California, and on production, as in the Appalachian field. The method of establishing values based on production1 was worked out in the Appalachian fields and approximates the value remarkably well in some fields; but it is a rule of thumb and should be used intelligently. Briefly, the method is as follows: An arbitrary number of dollars (called the barrel-day price) multiplied by the number of barrels of settled daily production of the property gives the value. In its crudest application, the barrel-day price is determined by the "$10 to $0.01" rule, which means that the barrel-day price is one thousand times the prevailing price of oil. For instance, with oil at $3.50 per bbl. the barrel-day price would be $3500 per bbl. This rule, however, is not strictly applied, for the barrel price is varied according to whether or not the wells "hold up." But when a barrel price for a district has been fixed it is quite general to raise or lower the price with the fluctuation in the price of oil; here the"$10 to $0.0l"ruleisused extensively. However, the prospective purchaser takes into account tangible equipment upon the property, the extent to which the drilling program has been carried out, whether or not the wells are "shot" or natural, depth of wells, spacing of wells, paraffin trouble, etc. The basis of this method is settled production. As soon as production is considered settled, a flat barrel-day price is generally applied to all properties, no matter what their age. If it were possible to show that this flat rate was erroneous and that the value of the property depended on the point on the decline curve at which the wells happened to be (in other words, their age), and also on the operating costs, the future price

Jan 1, 1921

By M. B. Bever, A. M. Reti, A. K. Jena

The results of this investigation show that in the system SnTe-PbTe l) the solid solutions have small exothermic heats of formation relative to the binary compounds, 2) solid-solution hardening is almost absent, 3) the tin and lead atoms are .randomly distributed on the sublattice occupied by them and do not undergo an ordering transition during a thermal treatment designed to promote such a transition, and 4) the lattice parameter changes linearly with composition. These findings suggest that the solid solutions of tin telluride and lead telluride approach ideal behavior. THE binary compounds SnTe and PbTe form a continuous series of solid solutions.' Information on several physical properties of these solid-solution alloys has been published.1"3 In the work reported here, the heats of formation, microhardness, and lattice parameters of these alloys have been measured and the possibility of an order-disorder transition has been investigated. Order-disorder transitions occur in some solid solutions of binary compounds. In the system Bi2Te3-BizSes, for example, the electropositive bismuth atoms and the electronegative tellurium and selenium atoms always occupy separate layers. In the disordered alloy Bi2Te2Se, the tellurium and selenium atoms are randomly distributed on the layers occupied by them, while in the ordered alloy they occupy distinct layers.4 The NaC1-type (Bl) structure of SnTe-PbTe alloys consists of two sublattices, one of which is occupied by the electropositive tin and lead atoms and the other by the electronegative tellurium atoms; any ordering would be expected to occur in the sublattice occupied by the tin and lead atoms. PREPARATION OF SPECIMENS Polycrystalline specimens of PbTe and Sn1-xPbxTe (x = 0.25, 0.50, and 0.75) were prepared by melting stoichiometric amounts of lead (99.999 pct), tin (99.98 pct), and tellurium (99.999 pct) in evacuated and sealed Vycor tubes. Because of the deviation of tin telluride from the stoichiometric composition5 this compound was prepared by melting 49.8 at. pct Sn and 50.2 pct Te. The tubes containing the melts were quenched into water; the solidified ingots were removed from the tubes and annealed for 2 weeks in vacuum (PbTe approximately 100°C below its melting point, the three alloys 100°C below their solidus tem-

Jan 1, 1969

By Howard B. Bradley, Charles F. Weinaug

The phase behavior of a naturally occurring hydrocarbon system whose critical temperature is near the reservoir temperature has been described. The same volume per cent liquid was observed for the firkt time at three different pressures for isotherms immediately below the critical temperature. The shapes of the isothermal equilibrium constant curves necessary to predict this phenomena are discussed and illustrated. INTRODUCTION The phase behavior of a number of hydrocarbon systems has been reported; however, very little data are available on natural occurring hydrocarbon systems whose critical temperature is near the reservoir temperature. This appeared to be the case for the fluid studied here; therefore the pressure-volume-temperature data for this system were determined for preqentation. METHOD The PVT data were obtained with equipment similar to hat described by Weinaug and Katz,1 consisting principally of a two-section, double-windowed gauge mounted in a conktant temperature air bath. The procedure followed was essentially that used by Katz and Kurata5 except that a cathetom-eter, reading direct to 0.01 cm, was used to determine the height of each extreme phase limit. The system studied was formed by recombining -.vapor and liquid samples from the first stage separator of the well. Portions of these samples were displaced with mercury into the cell which had previously been filled with mercury. A predetermined amount of the liquid sample was introduced, while an excess of vapor was admitted. The resulting mixture was brought to equilibrium at the condition of the separator during sampling. By adding mercury to maintain the pressure, enough vapor was displaced to give a gas/oil ratio within the cell equal to that produced by the separator at the time of sampling. The remaining material was then considered to be equivalent to the reservoir fluid. An analysis of material in the cell, computed from analysis of vapor and liquid samples and the separator gas/oil ratio. is given in Table I. Table I — Composition of Hydrocarbon System Component Mole Per Cent Carbon Dioxide 0.13 Nitrogen 0.76 Methane 53.91 Ethane 14.20 Propane 9.64 Iso Butane 1.25 Normal Butane 4.29 Iso Pentane 1.12 Normal Pentane 1.87 Hexane 2.72 Heptanes + 10.11 hloleculal. Weight of Heptanes + 178.50

Jan 1, 1951

By W. R. Clough, M. E. Shank

IT has been noted in a study of the flow and fracture of nodular cast iron under biaxial stress conditions (complete results of which will be published later) that when this metal is subjected to stress it may undergo a striking density change. Such behavior was first determined by strain gage measurements made on tensile test specimens, and has since been substantiated by other types of measurement. The chemical analyses and mechanical properties of several nodular irons to be discussed here are given in Tables I and 11. Tensile data for iron A was obtained from a hollow cylindrical combined stress specimen of the same dimension as those used by L. F. Coffin, Jr.1 in his investigation of gray iron properties. Standard 0.505 in. solid tensile-test bars were used for irons B and C. On each specimen type, A-8 wire resistance strain gages were used—two diametrically opposing gages in the axial direction, two in the tangential or hoop direction. By subtracting elastic strains from the measured strains, the plastic strains could be calculated. By assuming that radial and tangential strains are numerically equal, a measure of permanent volume change can be obtained by summing the plastic strains. This appears to be a good assumption, since the metal either fractured, iron A, or readings were discontinued, irons B and C, long before necking took place. This calculated variation of volume increase with stress is given for irons A and B in Fig. 1. Data for iron C is almost identical with that for iron B. The volume change indicated by Fig. 1 has been substantiated by a more direct type of density measurement. A method developed by S. G. Fletcher and' Morris Cohen,' and completely described in the discussion of their article, has been used. The accuracy of specific volume measurement has been estimated as 0.00002 cu cm per gram. Essentially the method consists of weighing a sample in air and then immersed in water. Measurements were made before and after straining the material. The results shown in Table I11 were obtained by means of half-size (0.252 in. diameter, 1 in. gage length, 3/8-16 threads) tensile specimens. Initial measurements were made on the whole specimen before stressing. After stress-

Jan 1, 1955

By Howard B. Bradley, Charles F. Weinaug

The phase behavior of a naturally occurring hydrocarbon system whose critical temperature is near the reservoir temperature has been described. The same volume per cent liquid was observed for the firkt time at three different pressures for isotherms immediately below the critical temperature. The shapes of the isothermal equilibrium constant curves necessary to predict this phenomena are discussed and illustrated. INTRODUCTION The phase behavior of a number of hydrocarbon systems has been reported; however, very little data are available on natural occurring hydrocarbon systems whose critical temperature is near the reservoir temperature. This appeared to be the case for the fluid studied here; therefore the pressure-volume-temperature data for this system were determined for preqentation. METHOD The PVT data were obtained with equipment similar to hat described by Weinaug and Katz,1 consisting principally of a two-section, double-windowed gauge mounted in a conktant temperature air bath. The procedure followed was essentially that used by Katz and Kurata5 except that a cathetom-eter, reading direct to 0.01 cm, was used to determine the height of each extreme phase limit. The system studied was formed by recombining -.vapor and liquid samples from the first stage separator of the well. Portions of these samples were displaced with mercury into the cell which had previously been filled with mercury. A predetermined amount of the liquid sample was introduced, while an excess of vapor was admitted. The resulting mixture was brought to equilibrium at the condition of the separator during sampling. By adding mercury to maintain the pressure, enough vapor was displaced to give a gas/oil ratio within the cell equal to that produced by the separator at the time of sampling. The remaining material was then considered to be equivalent to the reservoir fluid. An analysis of material in the cell, computed from analysis of vapor and liquid samples and the separator gas/oil ratio. is given in Table I. Table I — Composition of Hydrocarbon System Component Mole Per Cent Carbon Dioxide 0.13 Nitrogen 0.76 Methane 53.91 Ethane 14.20 Propane 9.64 Iso Butane 1.25 Normal Butane 4.29 Iso Pentane 1.12 Normal Pentane 1.87 Hexane 2.72 Heptanes + 10.11 hloleculal. Weight of Heptanes + 178.50

Jan 1, 1951

Although the 71 Minerals operation is now closed down and the operating data presented is almost five years old, it is well worth describing since it was the first heap leaching operation conducted on a primarily silver ore. Tombstone was discovered in 1877 by Ed Schieffelen; and it became one of the most famous mining towns in the West through the stories connected with Wyatt Earp, Doc Holliday, and the Clanton brothers. Like many silver deposits .in the western United States, the Tombstone ores were relatively shallow. Several million ounces of silver were recovered in the relatively few years the camp was active; but mining virtually ceased by the early 1900s and was only continued in a small way until the 19409, a history similar to that of Tuscarora. The 71 Minerals operation was started in May 1975 and continued until late 1978 within the city limits of Tombstone on waste dumps; one was the' Lucky Cuss, Schieffelen's discovery, which had accumulated from the old underground operations. This waste material was mostly less than 50 mm (2 in.) in size, although there was some larger lumps. The grade was about 34 g Ag and 0.5 g Au per mt (1.0 oz Ag and 0.015 oz Au per st). The Tombstone dumps contained approximately 1,000,000 tons. The dumps and patented claims were held by a single owner, Tombstone Development Company, thus sufficient leaching material could be acquired from one source rather than dealing with a number of individuals, as is usual in putting together leaching ventures in old mining camps. 71 Minerals Ltd. was formed and a lease of the properties obtained. A site was selected close to the major mine dumps not far from down- town Tombstone. Pads approximately 90 m (300 ft) wide and 180 m (600 ft) long with an 8-degree slope were prepared using compacted old mill tailings as a base sealant on the pads. Mining was done at a rate of about 2,000 tons per day with a dozer, two scrapers, a front-end loader, and 30 ton trucks. The ore was dumped by the scrapers as it came from the dumps with no screening or crushing in 460 mm (18 in. ) layers and trimmed with the loader. Based on bulk sampling and laboratory testing, the majority of thegold and silver values were recovered within 30 days of leaching.

Jan 1, 1981

By C. Ernest Birchenall, Gerd M. Rosenblatt

The pressure and molecular weight of the antimony vapor over solid solutions of tin in antimony, containing 97.4, 94.9, 93.0, and 90.7 at. pct Sb, have been measured from 445° to 545°C by the torsion-effision method. The vapor is all Sb, within experimental error. A solidus curve which differs somewhat from the accepted curve has been calculated using the measured antimony activities. Metallographic examination of additional annealed alloys substantiates the accepted solidus. The solid solutions, which show negative deviations from ideality, probably do not deviate greatly from regular solution behavior. HANSEN' considers the Sb-Sn phase diagram to be well established with the exception of the boundary of the (Sb) phase.* Although there have been no pre- Their data can be combined with data for the solid alloys to calculate the solidus curve of the (Sb) phase. This paper presents measurements of the pressure ant1 molecular weight of antimony over Sb-Sn solid solutions containing 97.4, 94.9, 93.0, and 90.7 at. pct sb. Measurements were made by simultaneous use of the volmer3 torsion and Knudsen, effusion methods. The results of these measurements have been combined with the vapor pressure of pure antimony5 to obtain the activity of antimony in the primary solid solutions. The solidus curve calculated from these data differs somewhat from the accepted curve and is rather uncertain. Metallographic examination of Sb-Sn alloys was carried out to clarify the position of the solidus of the (Sb) phase. EXPERIMENTAL The apparatus and technique have been described previously.5 The measurements were made with the same effusion cells and torsion wire used in the measurements on pure antimony. The torsion measurements were calibrated with mercury at 30" using a mercury vapor pressure of 2.96 x 10-3 mm Hg determined by concurrent, absolute, weight-loss experiments. As in the measurements on pure antimony, an extraneous vapor was observed to distill off during the first run after the cell had been loaded with A fresh sample of alloy and during the first minute or two of every run. The change in composition after a series of runs with one sample was of the order of 0.1 at. pct and thus completely negligible in the calculation of the thermodynamic properties. The alloys were prepared from pieces of Merck antimony and Matheson, Coleman, and Bell reagent-

Jan 1, 1962

By O. D. Sherby, J. E. Dorn, C. D. Wiseman

MCLEAN' has shown that the total strain obtained during creep of aluminum polycrystals arises exclusively from the mechanisms of 1) microscopically observable slip, 2) subgrain tilting, and 3) grain boundary shearing. Extensive analyses, however, suggest that the high temperature creep of metal polycrystals is controlled by a single thermal activation process."" These somewhat contradictory observations might be reconciled if it could be shown that the activation energies are identical for each of the mechanisms isolated by McLean. Such identity of the activation energies, of course, would demand that the same unit process controls the functioning of each individual mechanism. Under these conditions the activation energies for creep of single metal crystals and polycrystalline aggregates and for grain boundary shearing should be identical. This paper is primarily concerned with the possible identity between the activation energies for high temperature creep of single crystal and polycrystalline metals. In addition, comparisons will also be made between the activation energies for creep of single crystals and polycrystals with previously reported activation energies for grain boundary shearing.0"8 Materials and Techniques The same high purity aluminum, lead, and tin were used in the creep tests for single crystals and polycrystalline aggregates. Single crystals of aluminum and tin were prepared by the strain-anneal technique, whereas lead single crystals were prepared by growth from the melt. The tensile creep stress was maintained constant by Chalmers-Andrade parabolic-type lever arms. Strains were measured to &0.0002 in. per in. with rack and pinion type extensometers, and temperatures were maintained to within & 0.2"C of the reported values by mercury-thermoregulated resistance-heated silicone oil baths. The previously reported unambiguous technique for determination of the activation energy for creep was employed throughout this investigation.' ." It involves periodic abrupt small changes in temperature during the course of creep, accomplished by rapidly replacing one creep bath at temperature TI by a second bath at T,. The abrupt change in creep rate from i, to & attending the abrupt change in temperature is due exclusively to the change in temperature, since both the stress and the substructure are identical the instant before and the instant after a change of temperature. Therefore, all other factors being identical where AH is the activation energy for creep and R is the gas constant. Results Typical examples of the creep rate vs creep strain data during temperature cycled creep tests of single

Jan 1, 1958

By J. H. Swislzer

TWO-LIQUID miscibility gaps have been found to exist in both the CaO-SiO, system above 1705 and the Cr,03 system above 2200"c. Glasser and 0sborn3 studied the extension of these miscibility gaps into the Ca0-Si0,-Crz03 ternary system and reported that the two-liquid region is not present at temperatures below the monotectic temperature of 1705°C in the CaO-SiO, system. The present authors, in connection with other work on surface-tension measurements and foam stabilities in the same ternary system,4 observed that the miscibility gap exists at temperatures as low as 1600°C. A brief experimental study was devoted to deter- mining tie-line positions in the two-phase region. The technique used was to obtain a separation of phases at 1600°C, then to quench-in the high-temperature phases and obtain a chemical analysis of each phase. It was necessary to take special precautions in obtaining a phase separation because of a tendency toward emulsification of the two liquids. The procedure followed is described in the schematic drawing in Fig. 1. A small platinum crucible containing several pinholes on its sides was placed inside a larger platinum crucible. An excess of Crz03 was placed in the outer crucible, together with a prefused binary CaO-Si02 mixture, and the Cr203 was allowed to diffuse through the pinholes and saturate the same binary CaO-SiOl mixture in the smaller crucible. After equilibration at 1600°C, the inner crucible contained only the lighter liquid (liquid A) saturated with Cr203. The outer crucible contained layers of both liquids. Experimental data were obtained by analyzing the entire contents of the inner crucible and only the bottom layer of the larger crucible (liquid B). The upper layer of the outer crucible was not suitable for chemical-analysis purposes because dispersions of the second phase sometimes were found in the samples. The technique is described in more detail in Ref. 4. The same method was used by Grieveson and urkdoan' to study a miscibility gap in sulfate-ferrite melts, where the liquids were difficult to separate because of similarities in density. In addition to the phase-separation experiments, a few others were conducted to obtain information

Jan 1, 1964

By J. E. Cannaday, R. J. Austin, R. K. Saxer

PREVIOUS investigators have determined activation energies and have postulated various controlling mechanisms for creep.'-' Recently Barrett et 01.I5 have suggested, as the result of their work with cadmium, that the apparent activation energies for creep (AHc) above 0.5 T, could be correlated by means of activation energies for self-diffusion (AHSD) and modulus of elasticity functions: AHC = AHSD - (5RT/E) dE/dT. The wide disparity of apparent activation energies previously obtained with nickel compared to those reported for other fcc metals and the desire to test the postulate of Barrett el al. prompted this study. The as-received 17.5-mil nickel wire used during this work assayed 99.87 pct pure, Table I. X-ray analysis indicated that the wire was in a stress-re- lieved state and metallographic examination revealed an equiaxed grain size of approximately 0.01 mm. Specimens degreased in acetone and cut to 1-1/2 in. lengths were tested in a cam-mechanized constant-stress creep machine. A vacuum of at least lo-5 mm Hg was maintained during all tests. Stresses were applied when thermal equilibrium was established. When a measurable (at least 0.5 pct) secondary creep was observed, the temperature was pulsed to a higher temperature. Pulsing time varied from 30 sec at 480°C to 2 min at 1300'C and above. Slopes of creep curves were determined after the initial acceleration in the strain rate had subsided and steady-state creep was achieved. To confirm the results obtained, additional tests were performed incorporating a temperature pulsing method suggested by sherby. In this method the load was removed during temperature pulsing and reapplied after thermal expansion had occurred. No appreciable differences in results were obtained. Tests were performed over a wide range of temperature (470" to 1310°C) and stresses (250 to 17,000 psi). The expression was used to calculate activation energies. In this expression T1 and T2 are the initial and final temperatures, and el and i2 are the creep rates at T, and T2. The variation of the apparent activation energies with the mean test temperature calculated by means of Eq. [I] are shown in Fig. 1. The mean test temperature (Tmean) was calculated from the relationship

Jan 1, 1967

By W. M. Small

Austria.—Austria produced some 430 cisterns of 10,000 kg. each of crude oil of a 0.9428 sp. gr. during 1934. Gosting II well near Zis-tersdorf was placed on the pump in August and at the end of the year was still producing about three cisterns daily. This well is owned by the Erdöl-Produktionsgesellschaft while Gösting I is owned by Raky-Danubia. Only five wells were completed in the republic during the year. These accounted for 1783.5 meters of the 2225 meters drilled. The only producer completed was Gosting 11. At the close of the year, four rigs were in operation and one rigging up. At least 8 or 10 new wells are planned in Lower Austria for 1935. The European Gas & Electric Co. put its 6-km. gas line into operation in May and has sold 12,301,550 cu. m. of gas to the Vienna City Electric Works. A 2-km. pipe line was built from Gösting II to the railway loading rack near Zistersdorf. Hungary.—No oil or gas was produced except a small amount of gas trapped from flowing artesian wells. The Government completed and abandoned a 1500-m. hole at Tisztaberek in northeastern Hungary and is drilling at 967 m. near Bogáes, 120 km. northeast of Budapest. It is unofficially reported it plans to drill two new wells in 1935. The European Gas & Electric Co. has a rig up for a test at Mihalyi in Transdanubia. Czechoslovakia.—In Gbely (Egbell) there were produced 1283 cisterns of 10,000 kg. of 0.935 sp. gr. oil and a small amount of gas used for fuel. This field is operated by the Government; 17 shallow producing wells and three dry holes were drilled, with a total of 3351 m. of hole completed. In Hodonin (Goding) there were produced approximately 1300 cisterns of 10,000 kg. each of 0.91 sp. gr. oil and a small amount of gas used for fuel. The field is operated by the Apollo, which drilled four producing wells averaging 460 m. in depth, one small gas well of 550 m., one small gas well 260, and one dry hole 230 m. Two wells were deepened a total of 80 meters. The Government is drilling below 800 m. in a wildcat test in eastern Czechoslovakia near the Rumanian frontier.

Jan 1, 1935

By R. R. Webster, H. T. Clark

I. A. Sirel—I would like to ask Mr. Sims what would the preferred hot metal analysis be as far as manganese and silicon are concerned if you used specially made iron for this process instead of basic iron. C. E. Sims (authors' reply)—A preferred composition would contain somewhat less silicon than the basic pig iron used in these experiments. High silicon requires a large lime addition. Lime must be added in sufficient quantity to neutralize the silica formed and to leave an excess for dephosphorization. Manganese presents almost no problem in operation. It is almost completely oxidized and, in burning, develops considerable heat. The evidence indicates, however, that, in continuous commercial operation, there will be an excess of heat produced, and the bath will need to be cooled in some manner as by the addition of scrap or by utilizing the energy for the direct reduction of ore. There do not seem to be any serious limitations on composition of pig iron. One heat was made with an iron containing 2.27 pct silicon and the phosphorus finished at 0.007 pct. In another, the iron contained 0.45 pct phosphorus which was lowered to 0.019 pct. This indicates considerable leeway in composition. D. R. Loughrey—We are all very much interested in the recent discovery of very large deposits of iron ore both in Labrador and in Venezuela. I would like to ask Mr. Sims if the iron ore at either or both of these places is such that it would lend itself to the manufacture of iron suitable for use in the turbohearth. C. E. Sims-—According to my information, those ores are not essentially different from ores now used in this country for making basic pig. They should, therefore, be adaptable to this process. D. I. Brown—You have spoken about the leeway, or spread in analysis of the various irons you can use in the vessel. I would like to have you tell us, if you can, about the different kinds of steels which can be made in such a vessel. The turbohearth process, or it might more aptly be called pneumatic openhearth, is a little different from that used in most Bessemer shops and in the one in which I worked. If we had a blow in the air over 10 min, the boss was in the pulpit in a hurry

Jan 1, 1951

By R. R. Hart, B. C. Wonsiewicz, G. Y. Chin

In recent years there has been increased miniaturization of electromechanical devices to keep pace with current trends toward smaller electronic components. A major problem facing the designer, however, is the higher stresses encountered by the material as a result of shorter springs. Hence an improvement in the elastic limit, as approximated by the 0.01 pct offset yield strength, would be highly desirable. An increase of 25 pct in the yield strength, for example, will permit a 20 pct reduction in both the length and thickness of a cantilever-type spring while maintaining the same compliance. One technique of improving the yield strength that has received little commercial attention is crystal-lographic texture strengthening.1,2 Texture strengthening is expected to be most beneficial in materials of hcp structure, but considerable gain can also be expected in cubic materials. A wire with a (111) fiber texture, for example, is expected to be 20 pct stronger than randomly oriented material, and 50 pct stronger than wire with a (100) fiber texture.293 For sheet specimens with a {110}(112) texture, characteristic of many heavily rolled fcc alloys, the (111) transverse direction is expected to be the maximum yield strength direction, about 20 pct higher than that in the (112) rolling direction.' In addition, the (111) direction is the direction of maximum modulus of elasticity for most cubic alloys. A large value of the elastic modulus could be desirable in designs where stiffer springs are required. To test the above idea, a 0.090 in. (-2.3 mm) thick commercial grade A (5 pct Sn) phosphor bronze sheet, a widely-used material for relay springs, was rolled from the spring-tempered condition (60.5 pct reduction) to various additional reductions up to a total reduction of 95 pct. Subsequently, additional material was obtained with a total thickness reduction of 97.3 pct Standard tensile specimens were prepared from the sheet material with the tensile axis parallel to and at 90 deg to the rolling direction. Tests were run on an Instron testing machine at a strain rate of about 0.050 min-l. Textures were determined by the use of the reflection pole-figure technique. Data were obtained using nickel-filtered CuKa radiation and with the aid of a Siemens pole figure goniometer. The X-ray pole figure studies show an incrzasing development of the texture toward the {110}(112) ideal

Jan 1, 1970

By W. F. Stowasser

Robert E. Hagen (Oliver Iron Mining Div., U. S. Steel Corp.)—Mr. Stowasser and his associates are to be congratulated on their achievements in developing the design of a pilot agglomerating plant, based on information obtained from experiments made in a laboratory sinter pot, and subsequently constructing and successfully operating this plant. In his Transactions article, May 1955 (vol. 201) Mr. Stowasser stated that the output of his heat treating strand was about 2 Lt per sq ft of grate area per day and that the fuel consumption was 0.7 to 0.8 million Btu per Lt of product. If it is assumed that the burning zone extends from the back of the ignition furnace to the beginning of the recuperation windbox, only about 1/3 of the grate area over the windboxes is utilized for burning pellets, and the actual rate at which partially dried pellets are burned is about 6 Lt per sq ft of grate area per day. It may be interesting to compare the above operating data with that obtained at the Extaca plant, where taconite concentrate is treated on a conventional sin- tering machine using limestone or hydrated lime additives with no recuperation of heat. The entire windbox area is used for burning, and a production rate of 2.5 Lt per sq ft of windbox area per day has been attained at a fuel consumption of 1.8 to 2.0 million Btu per Lt of product, the latter being considerably in excess of that reported by Mr. Stowasser, partly because a circulating load of returns amounting to 28 to 30 pct of the machine feed is used and because no attempt is made to recuperate heat from the waste gases. With the high capital and labor costs prevailing today, it seems that future development of the downdraft grate pelletizing process should be directed toward taking advantage of the high burning rate of predried pellets and increasing capacity, perhaps at the expense of fuel economy, by decreasing the proportion of grate area utilized by ancillary functions. For example, eliminating the cooling zone and using this area for burning would increase the proportion of grate area available for burning from 33 to 50 pct of the total windbox area, and a proportionate increase in capacity would result.

Jan 1, 1956

By W. P. Sykes

TUNGSTEN serves mankind in two major roles. The first of these is represented by the tungsten filament of the incandescent electric lamp, a common article of commerce. In the field of hard alloys it plays its second substantial part. A fortunate combination of physical properties in this metal ac- counts for its efficient service as a source of illumination. Tungsten melts at about 3400°C, has a relatively low vapor pressure and at the same time sufficient strength, both hot and cold, to serve satisfactorily as filaments, which may range in diameter from 0.060 to 0.0005 in. In the early days of the incandescent lamp, the pioneers realized the importance of using a substance of high melting point for the source of light. The metals osmium (mp approx. 2700°C) and tantalum (mp approx. 2850°C) were both employed to some extent. Tantalum actually attained some commercial importance in this field because it could be drawn into small wires of appreciable length. DUCTILE TUNGSTEN WIRE Before the year 1908, tungsten was considered a nonductile metal, since no one had succeeded in overcoming the brittleness so typical of the unworked metal at room temperature. The methods employed today in producing ductile tungsten wire were developed over a period of years. The process was largely determined by the exceedingly high temperature required to melt this metal. Even today the difficulties involved in producing an appreciable quantity of pure

Jan 1, 1953

CONTENTS PAGE ANDERSON, ROBERT J., and ENOS, GEORGE M.-Corrosion of Brass as Affected by Grain Size. Discussed by Henry S. Rawdon, Robert J. Anderson, Francis B. Coyle, William B. Price, and W. R. Webster 1 RAWDON, HENRYS., and MUTCHLER, WILLARD H.-Effect of Severe Cold Working on Scratch and Brinell Hardness. Discussed by W. H. Bassett, John Livermore Christie, John R. Freeman, Jr., W. R. Webster, William B. Price, Norman B. Pilling, D. J. McAdam, Jr., F. G. Smith, Zay Jeffries, F. E. Carter 3 WILLIAMS, ROBERT S., and HOMERBERG, VICTOR 0.-Relation of Heat Treatment to the Microstructure of 60-40 Brass. Discussed by 0. W. Ellis 14 Corrosion of Brass as Affected by Grain Size Discussion of the paper of ROBERT J. ANDERSON and GEORGE M. ENOS, presented at the New York Meeting, February, 1924, and issued as Paper No. 1282, with MINING AND METALLURGY, December, 1923. HENRY S. RAWDON,* Washington, D. C. (written discussion).-So numerous and so varied are the factors that affect the corrosion of metals that particular care is necessary in corrosion tests to eliminate so far as possible all extraneous factors. It appears to the writer that the question may well be asked as to whether all the necessary precautions have been observed in this investigation. It may be that the points to be mentioned were considered by the authors and found to be insignificant; however, there is nothing in the report to show this.

Jan 5, 1924

By Mark J. Klein, A. H. Clauer

The Snoek peak induced by solute nitrogen in chromium was studied. A rapid quenching rate is required to maintain nitvogen in solution in sufficient concentrations to be detectable by internal-friction techniques. An expression for the tertninal solubility, c, of nitrogen in weight pevcent is log,,c = -4130/T + 1.05. The diffusion of nitrogen in zhromium determined by internal friction is SNOEK&apos;S theory1 of the stress-induced ordering of interstitial solute elements in the bcc lattice has been used to deduce information on the behavior of interstitials in a number of bcc metals. Under the proper conditions, internal-friction studies of "Snoek peaks" permit a determination of diffu-sivities, solubilities, and precipitation kinetics of interstitial elements. Internal-friction studies of this type have been reviewed by Nowick,&apos; Wert,= Powers and Doyle,4 and others. The behavior of interstitial atoms in Group V-A metals and iron has been rather extensively studied in this way, and results are reasonably self-consistent. However, the study of interstitial elements using internal friction in the Group VI-A metals—tungsten, molybdenum, and chromium—is much less clear. Thus far, internal-friction studies have revealed a peak in tungsten tentatively attributed to carbon5 and a peak in chromium associated with nitrogen. In chromium, Bungardt and Preisendanz6 observed a peak at 180°C for a frequency of -1 cps which they associated with nitrogen. More recently, de Morton7 determined the diffusivity of nitrogen in chromium from studies of a nitrogen peak at 160°c for a frequency of -1 cps and from elastic aftereffect measurements. The objective of this investigation was to study the nitrogen peak in greater detail, to obtain information on the behavior of nitrogen in chromium. This information is of interest because nitrogen is known to have an embrittling effect on chromium. However, efforts to deduce the role played by nitrogen in influencing the mechanical behavior of chromium are handicapped by lack of information on its behavior and distribution in chromium. EXPERIMENTAL PROCEDURES The chromium wires used in these studies were drawn from arc-melted iodide-chromium stock that had been extruded, swaged, and centerless-ground to 0.25 in.-diameter rods. Internal-friction measurements were made in an evacuated torsional pendulum similar to the one described by Kê,8 utilizing wires 0.048 to 0.030 in. in diameter. A series of analyses of the fabricated wires showed that the major impurities were approximately 100 ppm Fe and a combined interstitial content of 50 to 100 ppm C, O, N, and H. A typical interstitial analysis of the wires after processing is 15 ppm C, 2 ppm H, 50 ppm O, and < 5 ppm N. Interstitial concentrations were determined by vacuum-fusion, combustion-conductimetric, and micro-Kjeldahl analyses. In general, vacuum-fusion analysis yielded a lower nitrogen concentration than did micro-Kjeldahl analysis. For consistency, the nitrogen concentrations reported in this investigation were determined by the former method. Heat treatments were carried out by encapsulating the specimens in quartz tubes containing argon. The fabricated wires were annealed at 1150°C for 1 hr to produce uniform recrystallized grain size of about 0.015 mm. Nitrogen and carbon were added to the fabricated wires by encapsulating them in a quartz tube containing ammonia or methane, and annealing them at 1150°C for 48 hr. In some instances, carbon was also introduced by coating the wires with carbon black prior to annealing.

Jan 1, 1965