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W. H. BASSETT,* Waterbury, Conn. (written discussion ?).-The effect of reducing gases on hot solid copper has been known for many years in the copper industry, and precautions taken to guard against it in the general practice in copper heating and annealing. In view of the statement that Bengough and Hill, in 1910, were the first to suggest the possibility of the formation of gas within the copper itself, it is interesting to note that in Harper's Magazine for April, 1904, an article, "Life and Diseases of Metals," by Professor Heyn, illustrated the effect of reducing gases on copper by a photograph, which is shown in Fig. 1. This he entitled "Copper burst asunder by disease." After referring to the effect of hydrogen on steel, he makes the following remark: "Similar symptoms of poisoning, caused by hydrogen or gases containing hydrogen (as gas for lighting purposes), are apparent in copper when exposed to red heat. Not every kind of .copper is susceptible to this poisoning in equal degree. Copper per-fectly free of cuprous oxide is entirely exempt from poisoning. Most of the various coppers of commerce, however, contain cuprous oxide, formed during the smelting process while exposed to atmospheric influences. In such coppers, containing cuprous oxide, hydrogen causes a terrible disease on the copper being heated red hot. The copper bursts asunder and is permeated by cracks. This disease is practically incurable and can be eradicated by resmelting only. The results work destructively according to the amount of cuprous oxide contained in the copper." It must have been evident to Professor Heyn, as it was to us on reading this article, that the bursting asunder of the copper was clue to the formation of steam. Practical copper heaters have known for many years that it was quite possible to produce blisters, or large gas holes, in the interior of copper plates or bars by heating to a high temperature in reducing gases. These facts, of course, do not detract from the value of the study of the action of hydrogen gas that has been made by Mr. Pilling, but simply illustrate that the practical effect of reducing gases on furnace-refined copper has long been a troublesome factor in the heating or annealing of that metal.

Jan 1, 1919

By H. F. Yancey, M. R. Geer, C. L. Allyn, R. H. Eckhouse

W. M. Bertholf—This is an excellent report of a well-conducted investigation, of sufficient scope to provide generally useful information. Some years ago we had occasion to test the Humphreys spiral on the middling from our table plant. The conclusions reached in this investigation come as no surprise to us. In certain applications it is virtually impossible to improve on the spiral from the monetary returns point of view even though its "efficiency" may be low. We have noted that in all successful applications of the spiral the feed is "classified," hence we were somewhat disappointed in the showing the spiral made on the Poplar Ridge coal, the only one of the four which could really be considered the equivalent of a classified feed. As was noted in the paper, however, this coal contained a considerable amount of middle and high-gravity material, apparently more than enough to make up for the theoretical advantage of small particles in these categories. A comparison of particle size in the various specific gravity classes of the four coals is given in table XXV. Table XXV. Comparison of Particle Size in Various Specific Gravity Classes. (Unit size, 150 m to 0.105 mm) Black Eagle Clements Poplar Ridge Rosly,n 1.3 Float 7.47 10.60 8.68 9.66 1.3 x 1.4 7.89 7.96 7.58 8.20 1.4x1.6 7.24 8.36 5.58 6.85 1.6 x 1.8 7.98 8.31 3.42 7.33 Sink 1.8 7.85 7.13 5.09 7.41 Avg 7.69 10.08 7.15 8.38 This tabulation indicates that there was very little difference in the size of the various gravity fractions for three of the coals, Poplar Ridge varying the most. Examination of figs. 3, 6, 7, and 8 reveals a general similarity of behavior for all coals except Black Eagle. Would the authors care to speculate on the reasons for the difference in the distribution curve for the sink 1.60 material in the washed coal of fig. 3 as compared to the others? This difference is particularly noticeable in the 8xl4-mesh size. Was there a "shape effect"? J. D. Price and W. M. Bertholf—The performance data on three of the coals studied appear to be typical, but there are certain departures from the general pattern in the case of the Poplar Ridge coal which are large enough to deserve special consideration. For example: 1. Despite the high proportion of sink 1.60 material in the feed, it was not possible to make a corresponding proportion of high-ash reject. (See table XVI.) 2. Even though approximately 70 pct of the feed was 1.40 float with an ash content of 6.6 pct, and this

Jan 1, 1951

By R. H. Eckhouse, M. R. Geer, H. F. Yancey, C. L. Allyn

W. M. Bertholf—This is an excellent report of a well-conducted investigation, of sufficient scope to provide generally useful information. Some years ago we had occasion to test the Humphreys spiral on the middling from our table plant. The conclusions reached in this investigation come as no surprise to us. In certain applications it is virtually impossible to improve on the spiral from the monetary returns point of view even though its "efficiency" may be low. We have noted that in all successful applications of the spiral the feed is "classified," hence we were somewhat disappointed in the showing the spiral made on the Poplar Ridge coal, the only one of the four which could really be considered the equivalent of a classified feed. As was noted in the paper, however, this coal contained a considerable amount of middle and high-gravity material, apparently more than enough to make up for the theoretical advantage of small particles in these categories. A comparison of particle size in the various specific gravity classes of the four coals is given in table XXV. Table XXV. Comparison of Particle Size in Various Specific Gravity Classes. (Unit size, 150 m to 0.105 mm) Black Eagle Clements Poplar Ridge Rosly,n 1.3 Float 7.47 10.60 8.68 9.66 1.3 x 1.4 7.89 7.96 7.58 8.20 1.4x1.6 7.24 8.36 5.58 6.85 1.6 x 1.8 7.98 8.31 3.42 7.33 Sink 1.8 7.85 7.13 5.09 7.41 Avg 7.69 10.08 7.15 8.38 This tabulation indicates that there was very little difference in the size of the various gravity fractions for three of the coals, Poplar Ridge varying the most. Examination of figs. 3, 6, 7, and 8 reveals a general similarity of behavior for all coals except Black Eagle. Would the authors care to speculate on the reasons for the difference in the distribution curve for the sink 1.60 material in the washed coal of fig. 3 as compared to the others? This difference is particularly noticeable in the 8xl4-mesh size. Was there a "shape effect"? J. D. Price and W. M. Bertholf—The performance data on three of the coals studied appear to be typical, but there are certain departures from the general pattern in the case of the Poplar Ridge coal which are large enough to deserve special consideration. For example: 1. Despite the high proportion of sink 1.60 material in the feed, it was not possible to make a corresponding proportion of high-ash reject. (See table XVI.) 2. Even though approximately 70 pct of the feed was 1.40 float with an ash content of 6.6 pct, and this

Jan 1, 1951

By H. A. Shaw, H. G. G. Whitton

This paper describes the use of the electric-arc furnace for the production of tough-pitch, horizontal cast copper shapes and the production of copper anodes from tank house anode scrap. This installation is the only one of its kind in the United States. SINCE the initial use of electric-arc furnaces for refined copper melting on a commercial scale at Copper Cliff in 1936, this type of melting has been of extreme interest to everyone in any way connected with copper casting and fabricating. Early in 1948, Kennecott Copper Corp. decided to build an electrolytic copper refinery at Garfield, Utah. One of the major decisions to be made at that time was the type of furnace to be used for melting cathodes for casting into refined copper shapes and for melting anode scrap for the production of anodes. Based on the results obtained from arc furnaces by the Tnternational Nickel Co. of Canada, at Copper Cliff, and by the American Smelting and Refining Co., at Baltimore, coupled with certain important economic factors such as having an adequate amount of relatively cheap power available at the Magna Central Power Plant, high cost of poles and oil in the Salt Lake District, and the lack of natural gas at that time, the final decision was to install electric-arc furnaces rather than the standard type of rever-beratory furnaces. Experience has shown certain parts of the original installation to have been inadequate or in need of modification. Although the present status of arc-furnace melting at the Utah Refinery is far from perfect, nevertheless substantial progress has been made. At the Utah refinery, copper is melted in three 15-ft diam, size "M" Lectromelt furnaces, two of which are used for melting cathodes and one for remelting anode scrap. Each furnace is energized from a 13,800-225 v, 3-phase, 60-cycle, 6000-kva (at 40°C rise) oil-immersed water-cooled transformer. Auxiliary equipment for each refined copper furnace includes a charging machine, launders, ladle, 40 ft diam Walker-type casting wheel, bosh, and inspection conveyor. The anode furnace differs in that it is charged by hand from an elevated platform and the anodes are picked off the 24-ft diam casting wheel by a takeoff hoist and loaded directly into specially designed trailers, Figs. 1 and 2. Electrical Equipment Electric power to operate the arc furnaces is generated at the Kennecott-owned Magna Central Power Station two miles distant and transmitted to the Refinery outdoor substation at 44,000 v. At this point it is stepped down to 13,800 v and carried through concrete-lined underground tunnels to the switchgear and then to the primary side of the furnace transformers. The power is conducted from the Y-connected secondary bus bars of the transformer to the electrode arms by means of 22 flexible copper cable conductors per phase. Each cable has a cross-sectional area of 1,750,000 circular mils, giving a total area of 38,500,000 circular mils per phase. The power is carried from these cables to the three individual electrode holders by means of water-cooled copper bus tubing. The electrode clamps are incorporated in the electrode holders and are released by air pressure working against a spring in the clamp control cylinder. The movement of the electrode arms is either automatic or manual. The automatic control is used during melting and is regulated by three Westing-

Jan 1, 1954

By R. F. Miller

DUE to wartime secrecy restrictions a large part of the technical information developed by government and industrial laboratories was withheld from distribution. Much of this information has now been released or "declassified" and reports of technical work carried out during the war in allied and enemy countries are also becoming available. Information on the latter subject has been augmented by the work of the Technical Industrial Intelligence Corps of the U. S. Army. Through the Joint Chiefs of Staff, rep¬resentatives of this Corps co-operated with the British Combined Intelligence Observations Subcommittee, and some of the observations were made by combined personnel of both groups. The U. S. Government has undertaken the indexing and abstracting of all of this information in the Bibliography of Scientific and Industrial Reports, a weekly bulletin which appeared first early in 1946. Other publications, such as the Bulletin of the British Iron and Steel Institute and The Metals Review of the American Society for Metals, provide abstracts of domestic and foreign magazine articles and papers presented to technical societies. However, they do not cover the industrial and government reports recently released by the Government nor the reports of the Army investigators hence the new bibliography is a welcome addition to our metallurgical library.

Jan 1, 1947

By H. DeWitt Smith, W. H. Sirdevan

The mine operated by the United Verde Copper Co. is situated near Jerome, Ariz., on the eastern flank of the Black Hills, at an elevation of approximately 5500 ft. (1676 m.) above sea level. The mine and the town of Jerome are located on a steep hillside, which slopes rapidly to the valley of the Verde River. The smelter town of Clarkdale is situated in the Verde valley 4.1 mi. (6.5 km.) distant in an air line from Jerome, and at an elevation of 3560 ft. The two towns are connected by the standard-gage railroad of the Verde Tunnel & Smelter R. R., a subsidiary of the United Verde Copper Co. This road is 11 mi. long and has a compensated 4 per cent. grade. At Clarkdale, it connects with the Verde Valley branch of the Santa Fe R. R. The narrow-gage (36-in.) line of the United Verde & Pacific Ry. was, until 1919, Jerome's only rail connection with a main trunk line. This road connects with a branch line of the Santa Fe system at Jerome Junction, after traversing 26 mi. of mountainous country. From the time of its location, in 1876, until its purchase by Senator W. A. Clark, of Montana, in 1889, the United Verde mine was worked on a small scale and shipments of high-grade gold-silver ore were made from the surface workings. Until 1894, when the narrow-gage railroad to Jerome Junction was completed, all supplies for the mine and smelter

Jan 1, 1922

By G. E. Archie

THE usefulness of the electrical resistivity log in determining reservoir characteristics is governed largely by: (I) the accuracy with which the true resistivity of the formation can be determined; (2) the scope of detailed data concerning the relation of resistivity measurements to formation characteristics; (3) the available information concerning the conductivity of connate or formation waters; (4) the extent of geologic knowledge regarding probable changes in facies within given horizons, both vertically and laterally, particularly in relation to the resultant effect on the electrical properties of the reservoir. Simple examples are given in the following pages to illustrate the use of resistivity logs in the solution of some problems dealing with oil and gas reservoirs. From the available information, it is apparent that much care must be exercised in applying to more complicated cases the methods suggested. It should be remembered that the equations given are not precise and represent only approximate relationships. It is believed, however, that under favorable conditions their application falls within useful limits of accuracy.

Jan 1, 1942

By G. E. Erdman

Gouverneur Talc produces a dry mineral filler from the tremolite talc rocks located near Gouverneur, New York. The raw material for this rock powder is a silicate rock and dust is controlled by water sprays whenever it becomes a problem underground. In the milling operation, there are some nine baghouse-type dust collectors which are utilized for the control of dust created in the crushing and grinding process. These collectors have been installed over a period of years since 1947 and are assigned to specific areas where the particle sizing of the dust can be returned to the plant circuit or product involved at the point of collection. It has been found very advantageous to mount most of these collectors on the top of the mill building and packhouses where the return of the dust can be accomplished by a gravity feed. In the years of effort involved in efficient control of dust generated in the plant, many things have been learned in the construction of ducts for control valves. The company has found useful such things as grasshopper legs for interconnecting silos with similar products, the elimination of fiat dust ducts, cleaning cyclones for coarse dust or heavy loadings, refractory linings for cyclones and certain duct areas, and the avoidance of square intersections when diverting or combining ducts. Operating cost records indicate that collectors handling the finest dust have the least expense. Operating costs on high-temperature dusts generally run higher than other types of material collected. Experience further indicates that the multiple cyclone-type collectors can provide a low cost and efficient way of removing hot dusts from process air streams before the introduction of the material into a baghouse. High moisture conditions and cold northern climates have been found to combine and create conditions under which baghouses can not efficiently function as dust collectors. Gouverneur Talc feels that its several dust collection systems have been a considerable maintenance expense but well worth the cost when it came to safeguarding the employees' health and preventing air pollution.

Jan 1, 1974

By R. W. Raymond

AT the Pittsburg meeting of the Institute, in March, 1910, the death of Mr. Metcalf was announced, and Col. H. P. Bope, of Pittsburg, delivered in memory of him a brief but eloquent address, which, though expressing the sorrow of Mr. Metcalf's friends, and, in general terms,. the debt of gratitude which his country and his profession owed to him, was not intended to be a complete survey of his life and work. With Colonel Bope's permission, and with the aid of some of the statements in his address, I substitute for it, in our Transactions, this more detailed, yet still inadequate memorial. As Colonel Bope justly remarked, the men who could do justice to this theme-such men, as Jones, Chalfant, Bennett, Oliver, and Park-passed away before Metcalf, leaving him almost the last of the generation of great steel-makers who made Pittsburg the Sheffield of America, and who discharged a double function, as the rear-guard of the old metallurgical practice and the van-guard of the new. I knew many of them; would that I were better qualified to celebrate their achievements. William Metcalf was born Sept. 3, 1838, at Pittsburg, Pa., where his father, Orlando Metcalf, was an eminent member of the bar. At the age, of sixteen, he entered the Rensselaer Polytechnic Institute, at Troy, N. Y., from which he was graduated in June, 1858. Returning to his native city, he became an assistant engineer in the Fort Pitt Foundry, of which. he was made Superintendent in 1859. This famous establishment produced the largest castings and heaviest machinery then known in the United States;-and Mr. Metcalf's intense, intelligent and incessant study of his business prepared him as a manufacturer for a patriotic service to his country more valuable than, as a soldier, he could have rendered in the field. The call came in 1862, when the government needed, above all things, a supply of field, naval and siege artillery. The

Apr 1, 1911

By A. H. Geisler, R. F. Mehl, C. S. Barrett

The complicated nature of the property changes that accompany age-hardening has made it necessary to reconsider and to elaborate the simple dispersion theory.l It has been apparent for some time that more direct information is needed concerning the atomic mechanism of precipitation from solid solution if the theory of age-hardening is to be developed past a purely qualitative stage.‡ Fortunately, in recent years information has been developed which allows us to trace in detail the lattice changes accompanying the process of precipitation from solid solution. This information relates chiefly to the sequence of the several stages of lattice alteration by which the matrix lattice is transformed to the equilibrium precipitate lattice, and permits reasonable inferences to he drawn concerning the states of internal strain that accompany these stages. This information is most complete for the solid solution of copper in aluminum. The equilibrium precipitate is the 0 phase, "CuAl2." This forms in plates, parallel to the {100} matrix planes. The atom pattern and atom spacing on the plane in 0 lying parallel to this plane are roughly similar to those opposite it in the matrix.3 The formation of 0, however, is preceded by the formation of a transition lattice 0': which again lies parallel to the matrix {100} plane, but in this case the matching of atom pattern and spacing across the matrix-precipitate interface is nearly periect; thus there is lattice coherency across the interface and the interface is a plane of separation in only a very limited sense.'8 Particles of 0' may be recognized microscopically and form a well-defined Wid-manstatten figure.* The 0' lattice is recognized by the occurrence of diffraction lines on powder photo-grams or of spots on Laue photograms which may be analyzed in the usual ways to determine the lattice type and the lattice spacings. Very recent research 6, 7, 1 has shown, however, that streaks occur on the Laue photogram at an earlier point in time during the aging process. These streaks have been attributed to a preferential clustering of copper atoms into small platelike elements of only a few atoms in thickness and a lew hundred atoms in diameter, probably of the composition of " CuA12," which may be designated as Guinier-Preston zones or aggregates.1 It is difficult if not impossible to determine the lattice type and lattice spacing in these aggregates. It is possible1 that these aggregates are in fact ?' in a high State of dispersion; the inclination to argue this is strong, as we shall see later. Never-

Jan 1, 1941

By R. F. Mehl, C. S. Barrett, A. H. Geisler

The complicated nature of the property changes that accompany age-hardening has made it necessary to reconsider and to elaborate the simple dispersion theory.l It has been apparent for some time that more direct information is needed concerning the atomic mechanism of precipitation from solid solution if the theory of age-hardening is to be developed past a purely qualitative stage.‡ Fortunately, in recent years information has been developed which allows us to trace in detail the lattice changes accompanying the process of precipitation from solid solution. This information relates chiefly to the sequence of the several stages of lattice alteration by which the matrix lattice is transformed to the equilibrium precipitate lattice, and permits reasonable inferences to he drawn concerning the states of internal strain that accompany these stages. This information is most complete for the solid solution of copper in aluminum. The equilibrium precipitate is the 0 phase, "CuAl2." This forms in plates, parallel to the {100} matrix planes. The atom pattern and atom spacing on the plane in 0 lying parallel to this plane are roughly similar to those opposite it in the matrix.3 The formation of 0, however, is preceded by the formation of a transition lattice 0': which again lies parallel to the matrix {100} plane, but in this case the matching of atom pattern and spacing across the matrix-precipitate interface is nearly periect; thus there is lattice coherency across the interface and the interface is a plane of separation in only a very limited sense.'8 Particles of 0' may be recognized microscopically and form a well-defined Wid-manstatten figure.* The 0' lattice is recognized by the occurrence of diffraction lines on powder photo-grams or of spots on Laue photograms which may be analyzed in the usual ways to determine the lattice type and the lattice spacings. Very recent research 6, 7, 1 has shown, however, that streaks occur on the Laue photogram at an earlier point in time during the aging process. These streaks have been attributed to a preferential clustering of copper atoms into small platelike elements of only a few atoms in thickness and a lew hundred atoms in diameter, probably of the composition of " CuA12," which may be designated as Guinier-Preston zones or aggregates.1 It is difficult if not impossible to determine the lattice type and lattice spacing in these aggregates. It is possible1 that these aggregates are in fact ?' in a high State of dispersion; the inclination to argue this is strong, as we shall see later. Never-

Jan 1, 1941

By P. B. Baxendell

The appraial of producing properties and profitability ntzalysis of a proposed capital expenditure are based on the same principles. In both problems a projection of future cash income is. cornpared to one or more capital expenditures. Several different methods have been in use either to compute a price to obtain a given earning power on the investment or to compute the earning power which will result from a given capital expenditure. One of these, the "Average Annual Rate of Return" method, computes in a simple manner the ratio of the present value of the future earnings after amortization to the present value of the undepreciated balances of the investment over the life of a project. This method, not well known generally, appears to have some rather unique advantages in reducing the computation work required, eliminating trial-and-error solutions, and providing a more accurate answer when applied to oil industry investments subject to the unit-of-production basis of amortization. Its derivation is given and its versatility demonstrated in the solution of certain everyday investment problems. A number of charts, useful in applying this method to profitability analysis and appraisal work, are provided. The current trend in the market values of producing properties is shown. INTRODUCTION Making sound capital expenditure decisions requires an objective means of measuring the productivity of individual investment proposals. Since the best measure of the economic worth of such proposals is their ability to produce profits, it is common practice to grade proposed capital expenditures according to their annual earning power as a percentage of the outstanding capital. The same principles which govern the determination of the rate of return of proposed capital expenditures also apply generally to the problem of determining the appraisal value or purchase price of income-producing oil and gas properties. Both problems are of prime importance in the producing phase of the oil business, where management is faced daily with decisions to drill or not to drill certain development wells, or with the determination of the appraisal value of producing properties. The common feature in both problems is that a projection of future cash income is compared with a known or estimated capital investment to determine itsiearning power or annual rate of return. In the case of development drilling, the cost of the proposed well can usually be estimated with a fair degree of accuracy and the problem consists of finding the rate of return on the invested capital. In the case of appraising producing properties, on the other hand, the desired rate of return is usually known in advance and the problem consists of determining the purchase price which, for the given income projection, results in the fequired rate of return. Certain accounting procedures common to the oil and gas producing business make these two problems and their solutions somewhat different from corresponding problems in other industries, and, in certain ways, simpler. The main difference is in the amortization policy which, for oil and gas production, is frequently on a unit-of-production basis, compared to the amortization on a time basis used in many other industries. The purpose of this paper is to discuss briefly the various methods currently in use for the measurement of productivity of invested capital in producing properties and, in more detail, the derivation and application of what will be called the "Average Annual Rate of Return Method". This rather interesting and not too well known method has some very definite advantages in the solution of many problems common to the oil industry. For the sake of simplicity, federal income tax considerations have been disregarded in the examples used, since they do not affect the principles involved. The use of the production payment route in the sale or purchase of producing properties, which has been amply covered in many other publications, has also not been included in this analysis. METHODS FOK MEASUKING THE EARNING POWER OF INVESTED CAPITAL, Of the many different methods used to measure the earning power of invested capital, four are applicable to oil or gas production ventures. Depending on whether these four methods utilize one or two interest rates, and whether a fixed amortization pattern is used, they may be classified as follows.

George Smith, Sydney, N. S. Wales (communication to the Secretary): The very interesting paper by Mr. Emmons on " The Secondary Enrichment of Ore-Deposits " has just come under my notice; and its reference to my own paper* on " The OreDeposits of the Australian Broken Hill Consols Mine "† is therefore only noted some two and a half years after its publi-

Jan 1, 1903

By R. M. Keeney

Before the outbreak of the war in 1914, the only electric-furnace smelting plant operating on a commercial basis west of the Mississippi River was an electric pig-iron plant in California; rare metal ores were not smelted, concentrates of molybdenum, tungsten, uranium, and vanadium ores being shipped East for reduction. Practically no chrome ore was being mined, and only comparatively small amounts of manganese ore. Today there are two electric smelting plants in California, one in Washington, one in lowa, and four in Colorado; two plants are under construction in California, and one in Montana. Ores of manganese, chromium, molybdenum and tungsten are now smelted in the West, and although uranium and vanadium concentrates are still shipped to the East, they will probably be treated in western plants in a short time. The four electric-furnace plants in Colorado are listed in Table 1. Table 1.—Electric Smelting Plants in Colorado Capacity. Company Location KilowattB PRoductS Tungsten Products Co........... Boulder 800 Ferrotungsten, ferromo- lybdenum. Boulder Tungsten Production Co .. Boulder 400 Ferrotungsten. Ferro Alloy Co.................. Utah Junction 1200 Ferrochrome, ferrotung- sten. Iron Mountain Alloy Co......... Utah Junction 3000 Ferromanganese. Power for all of these plants is supplied by the Colorado Power Co. The plant of the Ferro Alloy Co., at Utah Junction, contains one 750-kw., three-phase furnace, to which power is supplied by three 250-lrw. transformers, connected /Y to give 129 volts on the furnace cables, the transformer ratio being 13,200 to 75 volts. The furnace operates with an actual voltage of 120 volts, and produces about 3 tons of ferrochrome per 24 hr. from 40-per cent. Cr2O3 ore. The furnace consists of a steel shell of circular cross-section, 8 ft. (2.43 m.) in diameter by 7 ft. (2.13 m.) deep, lined with magnesite, and having three vertical carbon electrodes 12 in. (30.48 cm.) in diameter. A 450-kw. furnace, of the same size as the 750-kw. furnace, is also operated on chrome ore. This furnace is three-phase in appearance, but operates electrically as a single-phase furnace. There are three vertical

Jan 1, 1920

By Harry A. Lipsitt, Douglas Y. Wang

A fatigue study in completely reversed axial tension-compression has been perforried on high-purity titanium and on three high-purity alloys of titanium. The alloys each contain approxi7nately 0.75 at. pct of a single interstitial element; carbon, nitrogen, and oxygen, respectivley. The results corroborate a previously published theory which proposed that strain aging under alternating stress was responsible for the fatigue limit behavior of certain alloys. The present data indicate that in these alloys an increasing strain-talline aging effect under alternating stress is provided by oxygen, carbon, and nitrogen, respectively. CURRENT research on the nature of the fatigue limit in metals suggests that the presence of a fatigue limit in metallic materials is a manifestation of strain aging that occurs under alternating stress.lm5 A comprehensive theoretical model based on the above hypothesis has been developed to explain the existence of a fatigue limit.' This model also provides increased insight into several other fatigue phenomena as under stressing, overstressing, and coaxing effects. The theory, as well, provides equal understanding for those cases where no real fatigue limit is observed. Briefly, this theory assumes that the S-N curve for a pure metal is a smooth function of the applied stress, and the effect of adding an element that is soluble (or forms a precipitate) in the pure metal is simply to shift the S-N curve to the right. If the added element confers the power to strain age, the result is a further shift of the S-N curve, this time upward and to the right. Since strain aging is not expected to be a strong function of stress, and since damage per cycle is known to be quite stress dependent, it is to be expected that there will be some limiting lower stress at which the strengthening due to strain aging will balance the damage due to crack propagation. This stress is the fatigue limit. The position of the fatigue-limit knee was thought to be a function of the magnitude of the strain-aging effect on both the finite and infinite life portions of the S-N curve. Although the strain aging hypothesis seems to be reasonably valid for bcc materials,2'6 it needed to be tested for both fcc and cph metals. This report is the first of a series concerning the fatigue-limit behavior of titanium with varying amounts of the interstitial solutes (C, N,, and 4) that are known to cause static strain aging in titanium. Yield-point effects have been reported for polycrys-talline high-purity titanium alloys containing either carbon, nitrogen, or oxygen.7'9 These effects were observed at testing temperatures in the range 100 to 300'. In addition yield-point and strain-aging effects have been reported for single crystals of titanium containing 0.1 wt pct C plus N.' These yield points were observed over a wide temperature range, but no room-temperature aging occurred. Aging at 180' was required to cause the return of the yield point. The magnitude of the yield phenomena in titanium containing interstitials is not expected to be as large as is observed in bcc metals because of several factors. Titanium has a very high chemical affinity for oxygen and nitrogen. The thermodynamic stability of solutions of oxygen or nitrogen in titanium is recognized. Lattice parameter measurements of titanium containing arbon, oxygen,1° or nitrogen" show that the "c" parameter is expanded more than the "a" parameter, but that up to about 2 wt pct this results in an insignificant change of the axial ratio 'c/a." Ehrlich" has shown that the sites occupied by interstitial atoms in titanium are spherically symmetrical and therefore a lattice expansion, at a constant c/a ratio, results in a simple dilation of the interstitial site. Such a dilation involving no shear has been shown to react only with edge components of dislocations.13 This causes only a weak pinning action. Shear stresses would be anticipated locally when only one of the two interstitial positions was occupied. The carbon atom will cause a symmetrical distortion of the lattice whereas the oxygen and nitrogen atoms have, in addition, the previously mentioned chemical affinity of titanium for these elements. These factors will result in a considerably smaller reduction of free energy upon the association of interstitial atoms with dislocations, and therefore a much weaker pinning than has been observed for the bcc metals. These considerations would lead to the hypothesis that of the interstitial elements considered here carbon would cause the strongest pinning effect in titanium where the amount of interstitial in solution is constant. This hypothesis will be borne out in the analysis of the present results.

Jan 1, 1962

By A. T. Yu

On March 18, 1964, the 52,000 dwt ore carrier M/S Houn Maru called at the port of Coquimbo, Chile, on its maiden voyage to take iron ore to Japan. This marked the first time a vessel of this size ever arrived at Coquimbo, and the event promises to drastically accelerate henceforth iron ore exports from Coquimbo province. This was made possible by the use of a versatile shiploading system recently installed by Cia. Minera Santa Fe. Coquimbo has no mechanized loading facilities other than six conventional 5-ton cargo cranes. Limited space on shore further complicates the stocking problems. To make the best of what is available, a meticulously organized semi-hand-loading system has been developed through the years.

Jan 5, 1964

HARD as it is at any time to provide more than three million tons of coal each year for power plants, the task really gets rugged in the wintertime when the fuel freezes solid in the cars. At the Marysville plant of the Detroit Edison Co. the problem of unloading cars of frozen coal was severe because there was an unloader over only one of the two tracks in the coal unloading house. Moving downward by their own weight, with no driving force to aid them, the spuds of this old unloader were unable to break through the crust on a frozen coal car. 20,000 Lb Force To meet this problem, a new mechanical car unloader was installed over No. 2 track and placed in service in December 1947. It is a Kenney type unloader built by Heyl & Patterson, Inc. of Pittsburgh, Pa., a modification of equipment originally designed to unload iron ore cars. The major advantage of this unloader is the force with which it can drive the sharp spade on the end of its ram down through the pockets of a frozen coal car. The unloader consists of the following major units: 1. A traveling bridge structure. 2. A traveling trolley. 3. A retractable and oscillating ram. 4. The operators cab and controls. The bridge is provided with safety hooks to prevent its being lifted from the rails by the upwards push of the ram. The bridge will travel 190 fpm and has sufficient traction on its four wheels to move three loaded 70 ton cars. The trolley runs on tracks supported by the bridge girders and also has upper tracks to control the push from the ram. Two of the single-flange trolley wheels are driven by a one and a quarter hp dc motors equipped with magnetic brakes. The ram is raised and lowered by a 20 hp dc motor equipped with a magnetic brake. A full stroke of a little over 14 ft is given the ram through its rack and pinion drive and the spade can be pushed down into a loaded car with a force of about 20,000 lb. A 15 hp dc motor with a magnetic brake is applied to this drive and is able to swing the ram 45º either side of the vertical. The usual procedure in emptying a coal car is first to drive the sharp spade down through the coal until the pocket is opened and the coal starts to run out the hopper. When all the hoppers are open, the sweeping action of the ram and spade is used to move the remainder of the coal in the car over to the open hoppers. The travel of the trolley permits cleaning the sides of a coal car with the edges of the spade, using the sweeping motion of the ram. It is still necessary to clean out the corners of the car by hand. Final Clean-Out This unloader was a new development and there were improvements to be made before it was completely satisfactory, such as reduction in speed and conversion to ac drive motors. However, it helped at Marysville and unloaded many frozen cars that would have taken a lot of heating to thaw out enough for the old unloader to handle. The mechanical coal unloader described above was a considerable improvement but still left a job to be done by hand-the final cleaning out of the coal cars. The ram had the ability to open a hole through the hopper cars, but did not meet required unloading speed. To eliminate hand cleaning a car shakeout, manufactured by Hewitt Robins, Inc. was added to the installation. This equipment is used to clean the coal car out after the unloader has provided an

Jan 1, 1952

By Mario L. Villa

During 1939 oil production experienced a new and important increase in Argentina in the productive areas of Comodoro Rivadavia (Territory of Chubut), Plaza Huincul (Territory of Neuquén), and those of the. Province of Mendoza. Production in the Standard Oil Company's field in the Province of Salta declined, but that of the Government oil fields in that province inereased 62.5 per cent.

Jan 1, 1940

By Mario L. Villa

During 1939 oil production experienced a new and important increase in Argentina in the productive areas of Comodoro Rivadavia (Territory of Chubut), Plaza Huincul (Territory of Neuquén), and those of the. Province of Mendoza. Production in the Standard Oil Company's field in the Province of Salta declined, but that of the Government oil fields in that province inereased 62.5 per cent.

Jan 1, 1940

By Fulton Flick

THE micrography and macrography of aluminum and its alloys present certain difficulties. Many of the difficulties attendant on the micrography have been removed by methods developed during the past few years, notably those of E. H. Dix, Jr.1 The development of grain size in aluminum and its alloys may be equally troublesome, yet comparatively little detailed attention appears to have been given to it. Satisfactory reagents. are available for the development of such structures in ferrous and most non-ferrous metals, but those applied to aluminum and its alloys, i. e., alcoholic or aqueous solutions of sodium hydroxide or hydrofluoric acid are not entirely satisfactory. Hanson and Archbutt,2 in speaking of these two reagents, state that "These two reagents give fairly satisfactory results, but they sometimes produce badly tarnished surfaces from which the surface deposit is difficult to remove." It has been our experience that neither of these reagents is to be entirely relied on for developing structures suitable for study or photography. This means that when the etch fails to produce satisfactory results the, specimen must be repolished, through the 000-paper at least, and then etched with another reagent. This procedure entails a con¬siderable loss of time, and the final results may not be all that might be desired. However, the reagent to be described, although not a panacea for all etching troubles, has improved results so markedly that it is felt that it is worth offering as a grain-size etch generally applicable to aluminum and aluminum alloys. Czochralski3 in 1915 mentioned the application of a solution of 10 to 20 c. c. concentrated hydrofluoric acid in 100 c.c. absolute alcohol, etching in this reagent being followed by dipping in concentrated hydrochloric-acid solution.

Jan 2, 1925