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By W. Jolley

Decarburized iron and Fe-3.28 pct Ni alloys were impact and tension tested in the temperature range of ambient to 4°K. It was found that alloying with nickel improves the fracture properties of the ferrite matrix. The improvement in toughness of iron alloyed with nickel is attributed to the effect of the nickel addition on the temperature and strain rate dependence of the yield stress as well as on slip behavior. The Fe-Ni alloy exhibits wavy slip when strained at temperatures down to at least 50°K. This behavior contrasts with that of the unalloyed iron where a change It is a generally accepted fact that of the common alloying elements of steel only nickel and manganese improve both the room-temperature yield strength and the notch impact properties. It has been argued for a number of years that manganese refines the ferrite grain size, the pearlite spacing, and the grain boundary carbides in medium- and low-carbon steels and thereby increases resistance to brittle fracture.''' This hypothesis recently was confirmed for a 0.04 pct C iron containing manganese, but at the same time from wavy to planar slip occurs at about 120°K. The observed lower temperature and strain rate dependence of the lower yield stress in the Fe-Ni alloy as compared to the unalloyed iron may be attributed to this difference in slip behavior. In contrast to suggestions published previously, transmission electron microscopy showed that the uniform dislocation distributions and the lack of dislocation tangles which are produced by low-temperature straining of bcc materials cannot be attributed to the absence of cross slip at these temperatures. no increase in notch toughness was observed in a decarburized Fe-Mn alloy.3 It thus appears that manganese only increases the toughness of Fe-Mn-C alloys by refining grain boundary carbides and has no toughening effect in carbon-free iron. On the other hand, the mechanism whereby nickel improves toughness has not been established. Hodge et a1.4 have clearly shown that a 3.28 pct Ni addition lowers the impact transition temperature of 0.02 pct C steel approximately 35°C when the grain size is maintained constant. Recently, Wullaert and Tetelman6 stated that nickel refined the grain boundary carbides of an Fe-C alloy and consequently increased the toughness. They also observed the previously reporteda-'

Jan 1, 1969

By R. L. Stone

None of the currently used methods of testing bentonites as binders for strengthening iron ore pellets is entirely adequate by itself. Since more knowledge was needed about 1) which properties of bentonite most affect pellet strength, and 2) the precise mechanism by which strengthening is produced, attention was paid to possible new techniques for rating bentonites. With the structural nature of bentonites — in particular, the montmorillonite component — the possibility of rating bentonites on the basis of zeta potential was investigated. These bentonites were also rated by conventional tests and measurements, including colloid content, barrel yield, pH, chemical analysis and physical tests on green and dry pellets. A mechanism for pellet bonding based on electro-kinetic forces between the bentonite and the iron ore concentrate appears to be feasible. In pelletizing, from 6 to 18 lbs of bentonite is added per ton of concentrate to give strength to the green and dry pellets. In some operations even more bentonite than is required for strengthening purposes must be added for moisture adsorption to pennit balling of the concentrate. Since bentonite is thus a major item in pelletizing, more knowledge about the way in which bentonites act as binders and better ways of rating this ability would help in the difficult job of selecting the right bentonite for a given concentrate. The fact of the matter is that although several methods are in current use for testing bentonites, none of these methods are consistently foolproof. For example, a given bentonite may rate high by several standard tests yet turn out to be a poor binder, and of course the reverse also occurs. Actually, more knowledge is needed about 1) which properties of bentonite most affect pellet strength, and 2) the precise mechanism by which strengthening is produced. In this study attention is therefore paid to possible new techniques for rating bentonites. With the structural nature of bentonites as a starting point, we investigated the possibility of rating bentonites on the basis of the zeta potential, i.e., the electrokinetic ootential on the montmorillonite colloids — the main component of bentonite binders. The zeta potential technique was applied to a range of commercial bentonites from several areas in the U.S. and abroad. These bentonites were also rated by conventional tests and measurements, including:

Jan 1, 1968

By R. J. Sullivan

DURING the past twelve months the Loudon pool of the Eastern Interior Coal Basin has become established as one of the two largest discoveries since the revival of exploitation in the Illinois region and now occupies a position among the important pools of the United States. On Aug. 1, 1939, production averaged 54,000 bbl. per day from 990 wells, having accumulated a total of 10,305,000 bbl. Its very active develop-ment promises to continue for fully another year. It is the site of one of the industry's most singular large-scale gas-injection programs. LOCATION AND RESERVOIR CHARACTERISTICS At present the pool embraces an area 15 miles long by 3 ½ miles wide in eastern Fayette County, along the western rim of the now well-known Illinois Basin's deeper part, through townships 6, 7 and 8 north and ranges 2 and 3 east of the Third Meridian. It is the northernmost, and most prominent, productive structure of a group extending over a 50-mile trend southward to the Dix pool of Jefferson County. Three horizons have been proved to carry production-namely, the Weiler sandstone at 1390 ft., the Paint Creek sand at 1460 ft. and the Benoist or Bethel, at 1500 ft. Geologically, they fall in the Chester series of the upper Mississippian system, where much of Illinois' early-day oil was found, having been laid down in shallow off-shore waters as a part of the vast delta deposit underlying central Illinois and parts of Indiana and Kentucky. As a result of this type of sedimentation, followed by repeated uplifts and warping along an anticlinal axis, differ-ential deposition of sands and shales contributing to great irregularity took place. This is further reflected by wide variations in permeability, porosity and thickness of all the sands and, accordingly, in the producing characteristics of wells. Permeabilities range as high as 550 millidarcies, with the average commonly lying between 60 and 100. For the three pay horizons the mean porosity is 18 per cent, at a calculated water saturation of roughly 30 per cent. The Weiler sand has an average thickness of 25 ft., the Benoist of about 23 ft. and the Paint Creek of approximately 18 ft. Of these three productive formations the Benoist

Jan 1, 1940

By J. B. Wagner, B. Swaroop

The atomic ratios of oxygen to iron in zlarious corn-posilions of wustite in the vicinity oj the reported p to n transformation were determined in the temperalure range between 950" and 1250°C. For these conditions, equilibrium vacancy concenrations have also been determined at vatious mixtures of C0,-CO. The data show a continuos introduction of iron vacancies as oxygen is introduced into wuistite. No phase change is observed with in the wuustite field. However, the value of n in the isothermal oxygen pressure dependence, the weight change shifts to 1ower values as the concentration of oxygen increases. WUSTITE is a metal deficit semiconductor with the majority lattice disorder being cation vacancies. Using the notation similar to that of Kroger and ink,' the dissolution of oxygen into wiistite using C02-CO mixtures is represented by, WHere v+! denotes a cation vacancy with k effective negative charges and kh • denotes k electron holes, h -. Applying the law of mass action and assuming a dilute solution of defects in the wiistite yields Where the square brackets denote concentrations. Furthermore, when k = 2 the cation vacancies are completely ionized, and both the concentration of cation vacancies and the concentration of electron holes are proportional to the third root of the ratio, PC /PCo. This analysis is valid for one particular mael based on an ideal solution at elevated temperatures (in this case t > 1000°C). At lower temperatures, it has been shown2 that the pressure dependence of the electronic conductivity changes in a manner which suggests that vacancies interact with or "trap" electron holes. At the very high concentrations of defects, 10'' to 10" per cu cm, these simple models no longer hold. Recently Tannhauser,3 Geiger et a1.' Bransky and Tannhauser; and Hillegas' have found an apparent p to n transformation in wiistite in the temperature range of 950" to 1300°C. This junction was found by thermoelectric and electronic conductivity measurements. Geiger eta1.' found that the electronic conductivity became almost independent of the oxygen pressure at high temperatures and oxygen concentrations within the experimental error. In addition, Vallet, Raccah, and coworkers6'7 have reported the existence of several "varieties" of wiistite which were reported to exist within what was heretofor presumed to be a

Jan 1, 1968

By M. R. Geer, Franklin T. Davis, H. F. Yancey

COKE with low phosphorus content is required by some of the electrometallurgical and chemical plants recently attracted to the Pacific Northwest by the hydroelectric power available from Bonneville and Grand Coulee dams. Shipping such coke into the area from eastern points involves a high freight charge, and during wartime consumes precious rail and ship-bottom space, so it is highly desirable to produce coke from the coking coals of Washington to meet the requirements of these industries. Although coke has been made from Washington coals since 1884, little has been known about their phosphorus contents or about the extent to which phosphorus could be reduced by cleaning. An investigation was undertaken, therefore, to determine the manner in which phosphorus occurs in the coking coals of Washington and its amenability to removal by ordinary coal-washing methods. PREVIOUS WORK Phosphorus is a deleterious element in coke used for numerous metallurgical processes, including the production of pig iron, yet comparatively little published information is available on the occurrence and elimination of phosphorus in any of the coals of this country. A variation from 0.009 to 0.062 per cent phosphorus in various horizons of the Pittsburgh bed in the Connellsville region of Pennsylania has been reported,1 and a reduction in phosphorus content from 0.020 per cent in the raw coal to 0.018 per cent in the washed coal was obtained in washing coal from the same bed in the Pittsburgh area;2 the latter figures represent average analyses for a year's operation of the washery on about 800,000 tons of coal. A reduction in phosphorus content from 0.018 to 0.011 per cent in washing coal from the Pittsburgh bed at another washery was observed, and the same report provides data on the phosphorus reduction obtained by separating 10 other coals on a bath of 1.35 specific gravity.3 European investigators have been especially active in correlating phosphorus content with petrographic analysis; fusain and durain generally contain the highest percentage of phosphorus, but this relationship is not universal.4 Some of these investigators have found that phosphorus is removed in the coal-washing process,5 but others have observed that the clean coal contained as much or even more phosphorus than the raw coal.6

Jan 1, 1944

By H. H. Reamer, B. H. Sage

An experimental investigation was conducted upon five different paired samples of oil and gas from a field in Louisiana. The study, with each pair of samples, included the measurement of the formation volume and the volume of the liquid phase for three mixtures of the oil and gas. The gas-oil ratio varied from approximately 200 to over 40,000 cu ft per bbl and measurements were made at temperatures between 40" and 250°F. The gravity of the tank oil for the five samples under investigation varied between 38.0" and 55.8" API. The composition of the oil and gas samples and their mixtures is submitted 'References given at end of paper. Manuscript received at the office of the Petroleum Branch February 21, 1950. in tabular form. A number of diagrams depicting the effect of temperature and gas-oil ratio upon retrograde dew-point pressure are presented. INTRODUCTION During the past two decades a fairly large number of investigations were made of the volumetric behavior of naturally occurring hydrocarbon mixtures. The earlier work of Beecher and Park-hurst' and a more recent report on samples from Dominguez Field2 are typical of research of this nature. Such studies have been used in estimating the volumetric behavior of fluids in producing fields other than those from which samples were taken. Progress has been made3.4.5 in correlating the influence of pressure, temperature, and composition upon the specific and formation volume of hydrocarbon mixtures of relatively low gas-oil ratios, but attempts to extend this correlation to higher ratios have not been particularly successful. The influence of composition upon the volumetric behavior of such systems cannot be simply related to a single parameter such as gas-oil ratio. In order to aid in the extension of the correlation of the volumetric behavior of mixtures of oil and gas to higher ratios, a rather complete study was made of five different pairs of samples from a Louisiana field. The complexity of the influence of composition upon the volumetric and phase behavior of such systems in the regions of retrograde condensation was indicated by earlier Work,6,7,8,9,10 and it is doubtful if simple correlations can be established in these regions with the information currently available. The terminology employed in this paper is identical to that utilized earlier."

Jan 1, 1950

By Alexander R. Troiano, Eugene P. Klier

SINCE the very early work on quenched structures, where the products of the martensite transformation had been recognized, this transformation has provoked much interest and study. Theoretically it was desirable to account for the extreme changes in physical properties resulting from the formation of martensite, as that information might lead to results of practical importance. Desirable information, therefore, was on the kinetics of transformation from austenite to martensite as well as on the physical constitution of the martensite. It has been known for years that certain steels quenched to room temperature will contain persistent austenite as well as martensite. Other important and now well- established features of the martensite reaction are the progress of the reaction on cooling only and the independence of Ar" with cooling velocities exceeding the critical velocity. These facts have been experimentally determined by various methods and investigators. Notable among the early investigators were Tammann and Scheill and Wever and Engel.2 Unfortunately, all investigators did not fully interpret their results, which, coupled with several investigations that yielded conficting results, caused a state of confusion that was not clarified until quite recently. X-ray investigations of martensite in steels3-6 indicate it to be a supersaturated solid solution of carbon in alpha iron. This supersaturation is evident from the appearance of a body-centered tetragonal structure with the addition of sufficient carbon. The dimensions of this tetragonal structure are alinear function of the carbon content within the limits of accuracy of the determinations. Slight tempering of tetragonal martensite leads to the destruction of the tetragonal structure, which is converted to a body-centered cubic structure. This phenomenon has precipitated a controversy concerning the nature and mechanism of the tempering of martensite. The facts in the case have been outlined by Epstein7 and more recently by Antia, Fletcher, and Cohen.8 The significance of Ar" on theoretical grounds is not clear, however, although considerable study has been devoted to its determination. The precise position of Ar" as a function of carbon content was first stated by Greninger and Troianos for steels covering a range of approximately 0.7 to 1.8 per cent carbon. The effect of alloying elements on Ar" has recently been the subject matter of investigation by various methods.

Jan 1, 1945

By E. T. Knight, John D. Gill

Much has been written and said concerning the alleged wasteful and uneconomic use of natural gas and petroleum. Espccially condemned has been the use of natural gas for the production of carbon black and the use of heavy fuel oil under steam boilers.' The critics of these usages of gas and oil have sought to make effective their verbal attacks on the industry by the repetitive expression of the words "inferior" and "superior" uses2 of petroleum. Thus, to employ natural gas for residential heating was to use it in a superior way; to use it for the production of carbon black was to use it in a wasteful and uneconomic way. To use petroleum for the production of automotive fuel was to use it in a superior way; to employ it as a residential fuel and as the prime source of power in an industrial plant was to use it in an inferior and uneconomic way. No doubt the objections to such employment of gaseous and liquid natural hydrocarbons originated in the belief that natural gas and petroleum are limited, nonregenerative mineral resources, and that the functions they perform can be just as well performed by other natural resources like coal13 of which practically unlimited reserves are known. The generations that have dominated each of the last four decades have counted reserves4 of petroleum in terms of a few years supply. Meanwhile, domestic demand for motor fuel rose spectacularly from a few million barrels in 1900 to more than 500,000,000 bbl. last year.5 The more imaginative and vocal critics drew startling word pictures of the catastrophe of 25,000,000 motor vehicles made useless and of the great automotive manufacturing and allied industries brought to an untimely end, and millions of workers left hopelessly unemployed by what they called the deplorably rapid depletion of the petroleum reserve. Many of the critics have been sincere advocates of the conservation of natural resources; many others, and in recent years probably the majority, have espoused the doctrine of conservation to promote their own self-interest rather than that of the public. The latest advocate of severe restriction in the use of petroleum for the alleged purpose of conserving the petroleum resource proposes to achieve that end by a bill,6 now before

Jan 1, 1938

By E. W. Krampert

The oil industry was very active in Wyoming in 1936, in contrast to the several quiet years preceding. Production for the year again increased about 7 per cent, following an 8 per cent increase in 1935. During the year, 85 oil wells were completed, compared to 55 in 1935. Three gas wells were completed in 1936, and three in 1935. At the end of the year 45 wells were drilling, as compared to 55 drilling at the end of 1935. Two new oil fields and one new gas field were discovered in Wyoming during the year. In the year 1936 Wyoming produced 14,475,431 bbl. of oil, a gain of 1,001,081 bbl. over the 1935 figure of 13,474,350. This increase, in the main, was due to the taking of light oil from the newly developed Sundance sand pool at Lance Creek, and from the new fields, Quealy and Medicine Bow, which contributed their first production this year. Most of the other old fields either were partly shut in in competition with the new fields, or showed a normal decline. This was especially noticeable in the black-oil fields, where production had been slowly but steadily increasing for a number of years. During 1936 black-oil production decreased approximately 100,000 bbl. as compared to 1935. The only black-oil field to show marked increase was Garland, which managed to take the market from less favorably located fields. The production of Wyoming in 1936 was 11,358,757 bbl. of light oil and 3,116,674 bbl. of black oil. Salt Creek, with a production of 6,015,000 bbl., is still the largest single oil-producing field, accounting for 42 per cent of the year's total production. Lance Creek, an old field, with newly developed production in the Sundance sand, reached second place this year for the first time in its history, with a production of 1,878,486 bbl. Lance Creek production will almost equal that of Salt Creek in 1937, if the present rate of production is maintained during the coming year. Oregon Basin, a large black-oil field, held second place in 1935, but owing to a greatly lessened demand for its production, dropped back to third place in 1936. This was in part due to greatly increased light oil available, and in part to the greater supply of black oil available at

Jan 1, 1937

By Stanley C. Herold

A few hates on the occurrence and significance of mud volcanoes in Colombia may be of interest at the present time, owing to the renewed activity in geological exploration of the coastal regions bordering the Caribbean Sea. The best-known volcanoes are found a few miles from the seacoast. One is situated to the south of Puerto Colombia; the second, to the east of Cartagena near the village of Turbaco; and the third, near the village of Puerto Escondido south of the Sinu River. Others are reported in more inaccessible localities. Usually they stand 2 1/2 or 3 ft. (0.762 or 0.914 m.) above the surrounding ground at the crater, though several craters from 10 to 20 ft. -(3.04 to 6.09 m.) "apart will often build up an extensive mound at low gradient. The shallow mound may cover 1/2 or 3/4 acre (0.2 to 0.3 ha.) with an elevation of 12 or 15 ft. (3.65 or 4.57 m.) at the, center. The craters are formed of hardened blue clay; the inside diameters vary from 14 to 24 in. (35.56 to 60.96 cm.). The rim is continuous, except on one side where there is usually a cut 3 or 4 in. deep, thus allowing an overflow. The craters are filled to the' rim-cut with a thick mixture of blue clay mud and water, which is kept in agitation by escaping gas. Fig. 1 shows the bubble in the act of bursting and Fig. 2 the appearance of the surface of the viscous fluid a second or so later. The frequency of the explosions is determined by the weight of the column of fluid in the neck of the volcano, consequently, such explosions are not synchronous in a group of craters. Ordinarily, there arc two or three explosions in about 3 minutes. The supply of gas is small but steady and sufficient pressure must accumulate before the bubble can enter the column of fluid. The water is derived from the surface and enters the scdirnentary strata not far distant from the volcano. During long dry seasons, as the supply of water fails the volcano dries and geyser action ceases. The temperature of the muddy fluid is normal; the gas is dry and inflammable. - No petroleum products come with the gas. On the surface of the fluid, there is sometimes a dark brown streaky scum, which

Jan 1, 1920

By F. S. Buffington, Morris Cohen

THERE is little quantitative information available concerning the effect of applied stress, in both the elastic and plastic ranges, on diffusion kinetics. Accordingly, a program has been undertaken to determine the rate of self-diffusion in high purity iron, with the specimens subjected to stress during the course of diffusion. Results are reported here for body-centered cubic iron at a diffusion temperature of 890°C. The iron used was 99.97 pct Fe, the principal impurities being 0.002 pct C, 0.008 pct 0, and 0.02 pct Si. The surface-decrease method of self-diffusion analysis was employed, and Fe55 Mn x-radiation, 2.9 years half-life) was the tracer element. Details of specimen preparation and equipment are given elsewhere.' Disks of the high purity iron, % in. diam x 1/4 in. thick, were annealed at 890°C for 18 hr in dry hydrogen to produce large grains of a ferrite. The faces of the disks were then surface ground, and possible grinding stresses were relieved by annealing at 890 °C for 45 min in vacuum. A layer of radioactive iron 0.00186 cm thick was electroplated on one face of each disk. The self-diffusion coefficient was calculated from the ratio of the radiation intensities emanating from each of these faces, as measured before and after diffusion.' The heating was carried out in a vacuum furnace (10-5 mm Hg) controlled to ±1.5°C. The specimens were loaded in compression between two quartz disks during the diffusion runs by means of a lever system operating through a vacuum seal. Thus one quartz disk was pressed directly against the radioactive face of the specimen, minimizing the vapor loss of radioactive iron. Steady-state creep occurred in all instances where permanent deformation could be detected, but the specimens did not exhibit appreciable transverse barreling until natural strains of 0.2 to 0.3 were attained. Essentially, the diffusion took place under uniaxial stress. The plastic strain in each case was obtained at the diffusion zone by measuring the diameter d there before and after the run: e = 2 In — do Let Du equal the self-diffusion coefficient which would have prevailed at the given temperature if no stress had been applied. This was calculated from the temperature-dependence equation which had been previously determined: —59,800 D, = 6.2 exp ( I sq cm per sec* [I]

Jan 1, 1953

By Dorsey Hager

NORTH -CENTRAL Texas has recently become a center of interest for the oil men of America. The bringing in of the McClosky well at Ranger, Eastland County, and the shallow pool at Brownwood, Brown County, in 1917, has stimulated interest in this area to fever pitch. Oil men from all over the United States are now investing there. The area of present interest is shown by the accompanying map (Fig. 1). The money spent in leases runs into millions of dollars. It is no exaggeration to say that a strip of country 200 miles (321 km.) long and 125 miles (201 km.) wide, comprising some 15,000,000 acres (6,070,310 ha.)., has been leased practically solid at a cost for rentals and bonuses of at least $1 per acre. The test holes contracted for will certainly number 400, at a cost of at, east $5,000,000. From what has been done in the past six months, $20,000,000 at least will be spent. To pay, returns on this amount of money, new production to the extent of at least 12,000,000 bbl. must be obtained. At present, the production from new fields will not average over 5000 bbl. per (lay; three wells at Ranger are producing 3000 bbl.; 250 wells at Brownwood produce 1000 bbl.; and the Gray well, Coleman County, is as yet an unknown factor. However, at Ranger there is every indication of developing a good pool covering from 1500 to 2000 acres (607 to 809 ha;), more or less, but the wells are deep, 3400 to 3800 ft. (1036 to 1158 m.), and cost $35,000 to $40,000 to drill. Large wells are necessary to pay for such expensive holes. As new wells are drilled, the gas pressure will be lowered rapidly, and large production need not be expected. For those oil men who expect a second Cushing or an Eldorado, Ranger holds little of promise. At Brownwood, Brown County, there are some 250 shallow wells (depths from. 200 to 350 ft.) averaging 4 to 7 bbl. per day. There is a chance of an extensive producing area, for these shallow sands to the southwest, and the opening of several thousand acres of shallow oil territory, and also some promise of deeper oil horizons in the Ranger horizon, but probably all under 2500 ft.

Jan 6, 1918

By T. Wasson

Midland and Isabella counties have been the centers of activities for the year 1932. The major part of the 6,967,000 bbl. produced during the year was obtained from the old Mt. Pleasant field and the Eastern Extension field. The total production to the end of 1932 for Michigan, from all fields since discovery, is 20,679,600 bbl. Production in the Eastern Extension field was obtained from Dundee limestone of Devonian age, at a depth of about 3600 ft. As a result of the year's activity in this area, the limits of the Eastern Extension have been defined. No new fields have been discovered. A number of prospective areas have been drilled and condemned by dry holes. Probably the most outstanding development of the year was the discovery of oil on the Yost farm, in sec. 35 of Greendale Township, Midland County, by the Pure Oil Co., in the early part of December. Production is from the Dundee limestone similar to that in the Eastern Extension but is 4 miles south of that area. The first well has averaged about 500 bbl. per day since completion. It is near the center of a solid block held by the Pure Oil Co., so that rapid development due to competitive drilling is not expected. During the early part of the year the Midland-Isabella area was under proration, but on May 17 proration restrictions were discontinued and remained so until the end of the year. While the Eastern Extension saw the principal activity, some work was done in other fields of Midland and Isabella counties, but very little new production was added. The Vernon field on the north showed a slight increase in production over 1931. The Leaton field decreased. The well in Porter Township, Midland County, is still kept in the production ranks but very little drilling was done in that area. The old Saginaw field, Saginaw County, still remains the only spot in the state where commercial production is obtained from the Berea sand. It showed a slight decline over 1931 with no new producers for the year. The Muskegon field on the west side of the state showed a considerable decline over 1931, but owing to the rejuvenation of some wells by the use of acid this drop was not as great as might have been expected. Only two new producers were drilled in that area.

Jan 1, 1933

By Walter Kauzman

ALL viscous or plastic flow of incompressible matter is the result of shear strain; the changing shape of any body that is being plastically deformed can be completely described in terms of the shear strain occurring at each point in the body.[t] Furthermore, the relative amounts of shear strain occurring in different parts of a body under stress depend upon the relative rates of shear strain at those different points, so that if the dependence of the shear rate of any material on the temperature, shear stress, previous history, etc., were understood, the principles of plastic deformation would be known, and we could calculate how a body made of a given material, having a given shape, and subject to a specified system of forces, would change its shape with time. It may be said, then, that the problem of plasticity resolves itself into, first, the problem of the rates of pure shear processes, and second, the application of what is known about pure shear to actual cases. It is the purpose of this work to investigate the former problem -i.e., the dependence of shear rates on temperature, stress, etc.-from the standpoint of recent developments in the field of chemical-rate theory and with particular reference to the phenomena occurring in the creep of metals and in the plastic flow of crystalline solids in general. It is left for the mechanical engineer, and perhaps the expert in hydrodynamics, to deal with the problem of applications.1 RESOLUTION OF MACROSCOPIC SHEAR INTO MICROSCOPIC MOVEMENTS; RESEMBLANCE TO CHEMICAL REACTIONS Just as any large body is made up of many small units, or atoms, so macroscopically observable shear is the result of many microscopic unit shear processes; just as the understanding of the behavior of large bodies demands the understanding of the atoms of which it is made, so the understanding of macroscopic shear demands the understanding of these fundamental unit processes. The study of shear from this "atomistic" point of view has made considerable progress. There has been fairly complete understanding of shear processes in gases for a long time, at least for nonturbulent flow, as a chapter on gaseous viscosity in any text on the kinetic theory of gases will prove. In recent years Andrade2 and Eyring3 have presented important theories for the flow of liquids and amorphous solids. Becker,4 Orowan,5 Taylor,6 Burgers,7 and Kanter8 have considered the

Jan 1, 1941

By Will Mitchell, T. G. Kirkland, C. L. Sollenberger

R. S. Handy (Santa Rosa, Calif.)—It would be interesting to learn the comparative results of treating the Korean scheelite ore described in this paper according to the following procedure: I—Follow the procedure described in the paper to the recovery of the sulphides by flotation. 2—Dilute the residue from the sulphide flotation strongly with water and disperse the contained colloids by adding a mixture of 75 pct sodium silicate and 25 pct quebracho to dispersion point. 3— Settle the dispersed pulp and decant the supernatant colloids. 4—-Dilute, settle, and decant the pulp until the settled residue is crystalline. Not over 10 pct of the tungsten minerals should follow the colloids. 5—Treat the settled residue by flotation, having established the proper pH. Oleic acid homogenized with cresylic acid or kerosene is more selective for scheelite than is oleic acid alone. (The recovery of the contained tungsten minerals should be practically complete in this operation.) 6—Deflocculate the tungsten concentrate from step 5 with the same dispersion agents as in step 2 and treat the deflocculated pulp by gravity. The minerals that tend to float with scheelite are generally of low specific gravity and the separation is efficient. The heavier contaminants, such as pyrrhotite and magnetite can be removed magnetically, leaving a practically pure scheelite. E. J. Pryor (Imperial College of Science and Technology, London)—It occurred to me that instead of using temperature as a differentiating control, more precision might be obtained with a reagent of a type we developed here for the flotation of high grade fluorspar in cold pulps. This reagent, which is manufactured on a modest scale in England, is based on oleic acid, which has been modified by our patented process to ensure complete stable dispersion at any desired concentration in water. It thus becomes possible to utilise unimolecular layers with good selectivity. In the fluorspar flotation for which we developed it, it is possible to hold a tight control on depressing quebracho for the calcite without substantial loss of flu-orite, and recovery exceeding 99 pct is not uncommon in the mill where it is in use, even under wintry conditions. No attempt has been made yet to extend the use of the reagent, as we have not completely overcome

Jan 1, 1952

By D. D. Button, L. D. Jaffee

INTEREST in the use of graphite as a high-temperature engineering structural material has recently increased markedly. However, actual use of this material has been limited, in part because information about its high-temperature mechanical properties has been lacking. The information needed includes not only reliable values for the properties, but also how to control these properties. Malmstrom, Keen, and Greenl have reported on the tensile and creep properties of some graphites above 2700° F (1500°C). They observed measurable creep under tensile loading at 4000 OF (2200 °C) and higher, with elongations of about 7 pct at 4500°F. Their typical elongation-vs-time curve showed the normal three stages of creep found for many metals at elevated temperatures. The specimens used were heated by passing an electric current through them. This method of heating caused a significant difference between the surface and axis temperatures, and may have affected the results. More recent work by kattus, in which the specfinens were also heated by their own resistance, showed very little plastic deformation for either slow or fast tensile testing or for creep testing. Work at this Laboratory, already reported,3 showed that for temperatures above 4500 "F and under conditions of slow tensile loading some commercial graphites exhibited elongations up to 20 pct. The work reported here is the continuation of a study of the tensile creep behavior of some commercially available synthetic graphites at temperatures up to 5300°F, and is preliminary to a more systematic investigation of the variables governing the high-temperature mechanical properties of graphite. MATERIALS TESTED The tests were conducted on six blocks from four lots of synthetic graphite bearing four different commercial-grade designations. These blocks were selected because their tensile stress—strain properties had been determined in previous work.3 Table I pre- sents the available information, supplied by the producers, on the processing of these materials. Also included in this Table are the densities and the tensile strengths at room temperature and 4500°F determined by the authors. EXPERIMENTAL TECHNIQUE The furnace used to heat the specimens for testing is shown in Fig. 1. The heating element was a graphite tube, 3-in. OD by 2 1/2 in. ID by 24 in. length. A spiral was cut into the 6-in. center portion of this tube to provide a high-resistance sec-

Jan 1, 1961

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 David Donoghue

THE. years 1901, 1910, and 1924 may be considered as the beginning of new eras in the history of the oil industry of the Gulf Coast of Texas and Louisiana. Spindletop, in 1901, with its enormous cap-rock production revealed the possibilities of the salt domes. The lateral sand development at Vinton, in 1910, renewed interest in the then known domes which were non-producing, or were producing from the cap rock or from sands above the cap rock. The discovery of three domes, Nash, Orchard and Long Point, in the year 1924, by means of the torsion balance and the seismograph, is the beginning of intensive explorations of the Gulf coastal plain by geophysical methods. Domes other than those mentioned have no doubt been found during the last few months of the year but tests have not been drilled to confirm the evidence of the instruments. DISCOVERY OF DOMES BY GEOPHYSICAL METHODS The Rycade Oil Corpn. operated the first torsion balance on the Gulf Coast in October, 1922, and the Roxana Petroleum Corpn. brought in one of these instruments and began work in December, 1922. The U. S. Coast and Geodetic Survey made some gravity observations at Damon Mound, in 1923, with a pendulum apparatus. In March, 1924, the Marland Oil Co. placed the first seismograph on the Gulf Coast and the Gulf Production Co. followed with one in May. In June, 1924, the Gulf Production Co. began operations with a torsion balance. The Atlantic Oil Producing Co., The Texas Co., and others have experimented with several types of instruments involving various principles. During the next few years, a great advance in geophysical methods may be expected, especially if one of the newly discovered domes should be productive. The first dome discovered was the Nash, in Fort Bend County, Tex., about 6 mi. east of Damon Mound. A slight elevation and two shallow wells containing sulfurous waters made the locality somewhat interesting from the standpoint of surface indications, and the torsion-balance measurements indicated the presence of a dome. On July 20, 1924, the Rycade Oil Corpn. No. 1 Wisdom encountered lime at a depth of 634 ft. and anhydrite at 639 ft. The hole was abandoned on Sept. 8, 1924, at 769 ft. in anhydrite. A cavity in the anhydrite caused much delay and the final abandonment of this test.

Jan 3, 1925

By H. M. Morse

Tinsley Oil Field.—Mississippi joined the oil-producing states when on Sept. 13, 1939, the Union Producing Company's G. C. Woodruff well No. 1, sec. 13, T. 10 N., R. 3 W., Yazoo County, was completed after drilling plug at 4540 ft. in the Woodruff sand of the Eutaw formation of Cretaceous, producing 300 bbl. per day of 34.4" gravity oil through a ¼-in. choke, with a gas-oil ratio of 80 to 1 and bottom-hole pressure of 2045 lb. This was the discovery well in the Tinsley oil field. The well was drilled to a total depth of 4567 ft. and no salt water was encountered. The sand underlies the Selma chalk formation. Nine producing oil wells and one dry hole were drilled and completed by the end of 1939. Two producing sands have been found in the Eutaw and a third sand in the top of the Tuscaloosa formation, called the Woodbine sand in Louisiana and Texas. Faulting is an important factor in the Tinsley field. Total oil production has been approximately 250,000 bbl. from the nine flowing wells. Total depth to top of productive zone was 4540 ft.; to bottoms of productive wells, 4580 ft. Net thickness of the producing formation is 20 to 40 ft., and its porosity is 24 per cent. The deepest zone tested was the Tuscaloosa, in which the depth of hole was 6112 feet. Six hundred and forty acres has been proved for oil production. Jackson Gas Field.—The Jackson gas field has shown a steady decline in the number of wells but the pressure has been maintained. This field is a perfect example of a water-driven field and the time of wells going to salt water is predictable. Five wells were drilled in the Jackson field, of which only one produced. Amory Gas Field.—Interest was renewed in the Amory gas field, where a new well was started in the fall of 1939. Geological Formations.—The deepest well drilled in 1939 was the Willmut Gas and Oil Company's Cleve Love S. F. Johnson No. 1, sec. 29, T. 6 N., R. 1 W., Hinds County. This well encountered the Lower Cretaceous, Trinity series from 3770 to 6422 ft.; Lower Mesozoic from 6422 to 6484 ft. The geological correlations and nomenclature of the formations in Mississippi are shown in the accompanying strati-graphic section.

Jan 1, 1940

By H. M. Morse

Tinsley Oil Field.—Mississippi joined the oil-producing states when on Sept. 13, 1939, the Union Producing Company's G. C. Woodruff well No. 1, sec. 13, T. 10 N., R. 3 W., Yazoo County, was completed after drilling plug at 4540 ft. in the Woodruff sand of the Eutaw formation of Cretaceous, producing 300 bbl. per day of 34.4" gravity oil through a ¼-in. choke, with a gas-oil ratio of 80 to 1 and bottom-hole pressure of 2045 lb. This was the discovery well in the Tinsley oil field. The well was drilled to a total depth of 4567 ft. and no salt water was encountered. The sand underlies the Selma chalk formation. Nine producing oil wells and one dry hole were drilled and completed by the end of 1939. Two producing sands have been found in the Eutaw and a third sand in the top of the Tuscaloosa formation, called the Woodbine sand in Louisiana and Texas. Faulting is an important factor in the Tinsley field. Total oil production has been approximately 250,000 bbl. from the nine flowing wells. Total depth to top of productive zone was 4540 ft.; to bottoms of productive wells, 4580 ft. Net thickness of the producing formation is 20 to 40 ft., and its porosity is 24 per cent. The deepest zone tested was the Tuscaloosa, in which the depth of hole was 6112 feet. Six hundred and forty acres has been proved for oil production. Jackson Gas Field.—The Jackson gas field has shown a steady decline in the number of wells but the pressure has been maintained. This field is a perfect example of a water-driven field and the time of wells going to salt water is predictable. Five wells were drilled in the Jackson field, of which only one produced. Amory Gas Field.—Interest was renewed in the Amory gas field, where a new well was started in the fall of 1939. Geological Formations.—The deepest well drilled in 1939 was the Willmut Gas and Oil Company's Cleve Love S. F. Johnson No. 1, sec. 29, T. 6 N., R. 1 W., Hinds County. This well encountered the Lower Cretaceous, Trinity series from 3770 to 6422 ft.; Lower Mesozoic from 6422 to 6484 ft. The geological correlations and nomenclature of the formations in Mississippi are shown in the accompanying strati-graphic section.

Jan 1, 1940