Search Documents

By Robert B. Sosman

THE relative temperature distribution within a coke oven and among the ovens in a battery can be obtained automatically for the operator's guidance by sighting a total-radiation pyrometer on the face of the coke as it is pushed out, and recording the surface temperature. Keeping the instrument clean and keeping its view of the coke unobstructed by smoke and dust are the principal problems. Typical records from three plants are presented in this paper, showing that the temperature patterns are reproducible. DEVELOPMENT OF METHOD The method of coke pyrometry described in this paper was introduced in 1936 by E. A. Lee, then Assistant Superintendent, now Superintendent, of the Coke Plant at Lorain Works, National Tube Co., Lorain, Ohio. At the request of the Coke Committee of the United States Steel Corporation, the Research Laboratory of the Corporation undertook to adapt the method to the somewhat different conditions met with at the Gary Works of the Carnegie-Illinois Steel Corporation, Gary, Ind., and at the Clairton Works of the same Corporation at Clairton, Pa. This work was done in cooperation with the Leeds and Northrup Co. of Philadelphia and later with the Brown Instrument Co. Division of Minneapolis-Honeywell Regulator Co., Philadelphia. We of the Research Laboratory wish to express our appreciation of the courtesies extended by Mr. Lee, by A. N. Cole, Superintendent of the Gary coke plant, and by D. P. Finney, Assistant General Superintendent in charge of coke-plant operations at Clairton. We are also indebted to the instrument companies for the loan of a part of the equipment. At Gary and Clairton the instruments were installed and various experiments were made by J. W. Bain, of the Research Laboratory of the United States Steel Corporation. PYROMETRY OF COKE The coke inside a by-product oven is almost completely inaccessible to pyrometric instruments. The temperature in the walls can conceivably be measured with thermocouples, but the atmosphere is usually strongly reducing, a condition well known to be destructive to the accuracy of the customary high-temperature couples. In some plants, periodic readings are taken with an optical pyrometer sighted into the top of the combustion flues. This is a useful measure for safety and general control, as it tends to prevent the damage that would result from overheating of the ovens. It does not, however, tell much about the temperature of the coke itself, because of the continually changing gradient in the wall between the coke and the combustion chamber. The best indication of the temperature of the coke itself must therefore be obtained by observation of the product as it is pushed out of the oven. The human eye is very sensitive to variations in brightness of a surface, and particularly to differences in brightness over a continuous hot surface.

Jan 1, 1942

By B. M. Larsen, L. S. Darken

SOME years ago we collated all laboratory data then available to us on the distribution at equilibrium of manganese and of sulphur between metal and simple slags, and used the results in setting up an equation, which proved to be in accord with determinations of the distribution ratio of manganese and of sulphur between liquid steel and open-hearth slag, over a wide range of operating conditions. We now present an outline of our calculations and inferences on these two closely related questions, which are of especial importance because of the advisability of conserving manganese wherever possible. In general. our results show that in the open-hearth furnace equilibrium between metal and slag, with respect to both manganese and sulphur, is substantially attained during the finishing period of the heat, or in about a half hour to an hour after any additions were made. This implies that the end result will be identical whether manganese is added as alloy or metal to the liquid steel or as oxide to the slag. The proportion of total manganese retained by the steel is favored: (I) by use of the minimum amount of lime, consistent with other operating limitations, required to give a lime-silica ratio of about 2.4, which usually corresponds to a minimum practical slag volume; (2) by a high concentration in the slag of MnO relative to FeO; (3) by high operating temperature. Absorption of sulphur by the slag from the liquid metal is favored: (I) by large slag volume; (2-by a high concentration of active (or "free") lime and of manganese oxide dis) solved in the slag; (3) by low concentration of silica, iron oxide, and phosphate dissolved in the slag. DISTRIBUTION OF MANGANESE BETWEEN SLAG AND METAL AT EQUILIBRIUM On the basis that the distribution of manganese between liquid steel and slag is controlled by the reaction [FeO + Mn ;7± MnO + Fe [A] slag metal slag metal] the distribution at equilibrium, at a given temperature, is expressed by the equilibrium constant for this reaction, which is defined as [K" aFPI OFeO ? aMn] where a is the activity of the molecular species denoted by the subscript. The activity of each of the several components, although it is not known precisely, is approximately equal to the concentration of each component expressed as its mol fraction; that is, as the ratio of the number of mols of the given component to the total number of mols of all the molecular species present in the metal or slag, as the case may be. Moreover, since the activity, or concentration, of iron in the liquid metal is in fact substantially constant, the term aFe may he combined with K" to give a new constant K'. Making these changes.

Jan 1, 1942

By Alfred H. Bell, George V. Cohee

In 1941 Illinois produced 134,139,000 bbl. of oil, or 9.5 per cent of the total for the United States, and ranked fourth among the states. The production for 1941 declined 9.2 per cent from the previous year's total of 147,647,000 bbl. Daily average production for 1941 was 366,000 bbl. At the beginning of the year daily production was slightly more than 326,000 bbl. and it remained at appoximately that amount until June, when there was a slight increase. The increase continued until the peak of 431,260 bbl. daily was reached for the week ending Oct. 4. Daily average production at the end of the year was approximately 387,500 barrels. The increased production during the last half of 1941 was largely due to the rapid development of the Johnsonville field, Wayne County, the Rural Hill field, Hamilton County, and the Benton field, Franklin County—new fields discovered in the current year (Fig' 1)—and the Woodlawn pool, discovered in 1940. Discoveries In 19 counties in southern Illinois, 44 new fields were discovered in 1941 (Fig. 2 and Table 2), and extensions to 40 fields were successfully completed (Table 3). At the end of the year there were 10,496 wells in the fields discovered since Jan. I, '937, as compared with 71965 wells at the end Of '940. The area proved for production in the new fields increased from 78,040 acres at the beginning of 1941 to 97,483 acres at the end of the year (Table I)—an increase of 19,433 acres, of which 9,955 acres are in the fields discovered during the current year, and the remainder of 9,478 acres in extensions to pools discovered earlier. Drilling During the past year, 3838 wells were completed in Illinois (Table 4), of which 2912 were oil producers, 13 were gas producers and 913 were dry holes; 76 per cent of the wells drilled were producers. Of the total number drilled, 591 wells are classified as "wildcat" and of these 84 (1 in 7) were successful in obtaining production. The results of an investigation to ascer-tain the reason for the locations of the wildcat wells are set forth in Table 5. Of the 591 wildcat wells, the 292 known to have been located by scientific methods were 21.6 per cent successful. The total footage of wildcat wells drilled in 1941 was 1,341,743 ft., of which a total of 216,995 ft. was drilled in successful wells. Exploration MEthods Subsurface geology and geophysics, largely the reflection seismograph, are still the principal methods used in exploration and development in the state. The number of seismograph parties operating throughout the year was as follows: seven parties on Jan. I, 1941; five on Apr. I; four On July I; eight on Oct. I; fifteen on Jan. 1: 1942.

Jan 1, 1942

By C Macquarie, Maurice Cook

Normally the grain size of cold-rolled and annealed copper sheet is of the order of 0.02 to 0.06 mm., and 0.1 mm., for example, would, for many purposes, be regarded as undesirably large. The occurrence of very large grain sizes in a few isolated cases of copper sheet led the authors to inquire into the causes giving rise to such unusual results. During the course of this work a very large number of experiments have been carried out to determine the effect of varying the conditions of the final and penultimate rolling and annealing operations, as well as of earlier rolling and annealing treatments. A correspondingly large number of observations have been made, but within the space of one paper it is possible only to outline relatively briefly what appear to be the more important of these experiments and observations. The presentation of the results does not follow chronologically the order in which the experiments were carried out and they have been rearranged for the sake of simplicity. In recent years a considerable amount of work has been done in connection with the recrystallization and grain growth in metals arid alloy. that take place on annealing, and a number of generalizations have beell reached. It is known that the crystal size in wrought material in the annealed condition depends on a number of factors, including the time and temperature of the annealing operations and the nature and amount of cold-work to which the material has been subjected. Results. however that are not covered by these generalizations can be obtained, which, in some instances, may even appear to be contradictory to them. Xccortling to these generalizations gradual changes in grain size are effected by progressive variation of the factors involved in annealing or cold-working. The work recorded in the present paper, however, relates to the development of grain sizes which are far beyond those normally encountered in ordinary annealing operations and far in excess of grain sizes which,

Jan 1, 1939

By M. M. Fine

THE problem of producing a uniform, medium-fine sand for glass-furnace feed has been of interest to the glass-container industry for many years. In the present investigation of the problem, conducted by the Bureau of Mines in cooperation with the Owens-Illinois Glass Co., Alton, Ill., a satisfactory method of producing such sand was developed. The investigation involved continuous-grinding studies of glass sand with flint and porcelain pebbles, steel balls and rods, and a simultaneous study of classification. The most satisfactory procedure consisted of grinding in a pebble or ball mill followed by a double classification: hydraulic classification to separate the oversize for return to the grinding unit and mechanical classification to remove fines and impurities from the ground sand. The proper application of this flowsheet usually yielded a graded sand containing less iron than the feed even when grinding was done in a steel-lined ball mill. The amount of sand ground into the so-called "dusting" sizes was, in all cases, less than 10 pct. Experiments were made which showed that this very fine sand could be beneficiated to a usable material. Background The advantages in utilizing a uniform, medium-fine sand as a feed for glass furnaces has motivated a considerable amount of research on the ,problem of producing such sand by glass producers and others. For the glass producer, the faster melting rate of such a graded sand offers the possibilities of reduced fuel costs and increased furnace capacity. In addition, there is the likelihood of improving the quality of the melt and thereby reducing the number of seeds (air bubbles) and stones (unrnelted grains) in the finished ware. Although the melting rate of a glass batch depends on other factors in addition to the grain size of the sand, there is experimental evidence to show that grain size influences the melting rate considerably. Potts, Brookover, and Burch' found that when the raw materials (sand, soda ash, and limestone) were always matched in- size, there was a great decrease in the melting time as the grain size of the materials was decreased. They found, too, that when the grain sizes of the soda ash and Limestone were held constant at 40 to 60 mesh, the minimum melting time occurred when 40 to 60 mesh sand was used. The increase in melting time with decrease in grain size beyond 40 to 60 mesh was due, they postulated, to accelerated demixing or separation of batch during melting as the grain size of the sand decreased in relation to the grain size of the other materials. An earlier investigatora found that the highest rate of melting and purifying ordinary glass was obtained when medium-size sand (0.385 to 0.120 mm, correspondingly roughly to 40 to 120 mesh) was used. Although batches containing smaller-size sand were found to fuse more rapidly, the time required to remove air bubbles from such melts actually increased the total duration of the process. Coarsegrained sand, it was stated, increased greatly the times of both melting and purifying. Although the laboratory data are difficult to confirm on a plant scale, observations by the Owens-Illinois Glass Co. indicate a higher furnace capacity of better-quality ware when a medium-fine sand is used in the batch. During the recent war, the glass producer was inclined to overlook a considerable variation in raw materials in the interest of higher production. For instance, table I shows the wide range in the amounts of various screen fractions in sand supplied by one producer to the Terre Haute plant of Owens-Illinois. The sand, from the northern Illinois St. Peter sandstone, represented material used by that plant over a period of a few years during the war. Since the war, the glass industry has insisted on

Jan 1, 1951

By N. P. Goss

Asterism appearing in X-ray Laue diagrams is an extremely sensitive index of changes in the internal structures of individual grains of polycrystalline metals. It indicates the existence of various forms of subboundary structure or subdivision within the grain. The present viewpoint is that the grain is made up of lattice blocks having substantially the same size and shape.l-4 When these blocks all assume exactly the same orientation, the crystal is perfect and asterism is absent. Cleaves and Thompson5 observed that the hardness of iron is virtually constant over a range of grain sizes. It is quite possible that the subboundary structure caused this, and that the latter is just as important as grain size itself. While the experiments reported here are not conclusive, they do support this viewpoint. Metals can, under certain conditions, be prepared entirely free from asterism, but this preparation does not necessarily require long heating or slow cooling, as will be shown here. In this paper a distinction is made between mosaic and distorted grain structures but the difference is only a matter of degree. In a previous paper9 it was shown that the grains can become distorted even during heat-treatment. The block structure exists inherently, even in a perfect crystal; the size and shape of these crystallites, or lattice blocks, varies, depending upon a number of factors. Goetz, for example: has shown that a metal before crystallizing from the molten state must go through a paracrystalline phase with oriented groups of atoms about 10-l4 to 10-l5 c.c., or 10-15 cm. in size. These crystallites, or blocks, appear to survive the most drastic cold-working, for it has been shown, and more elaborately by Wood's recent work," that cold-working cannot reduce the size of these crystallites smaller than of the order 10-5 cm. The interesting correlation brought out by the experiments of Goetz and Wood is that the block size after severe cold-working is of the same order of magnitude as the groups that formed in the metal just before crystallizing from the molten state. The work of Ewald and Rennenger17 and the now classical experiments of Darwin and James12,13 all strongly suggest the existence of a periodic structure of crystal. lites smaller than the grain itself. Related to this effect is the appearance of veinlike markings in the microstructures. Ammer-man and Kornfeld,16 in their experiments, did not observe any evidence of veining in specimens of alpha iron annealed below A3 and believed that veining was not due to impurities in the iron, as Northcott16 suggested; veining was observed by them only in specimens annealed above A3. Hanemann,16 Schrader and Tangerding found that annealing in hydrogen did not diminish veining and so it could not be caused by oxides. They concluded that veining was due to a slight difference in the orientation of ferrite lattice blocks. This viewpoint is well supported by the evidence presented here.

Jan 1, 1941

By C. C. Wright, T. S. Spicer

A characteristic property of bituminous coal is that upon being heated the coal becomes plastic, evolves volatile gases, and finally solidifies into coke. This fundamental characteristic is of utmost importance and is utilized in the production of the high-temperature coke upon which the steel industry is so dependent; but from the standpoint of operation in the domestic underfeed stoker this coking tendency seriously interferes with efficient combustion. When the coke formed has too strong a structure, certain difficulties result, such as low rate of burning, slow response to heat demand, and, in extreme cases, extinction of fire. The plastic mass prevents uniform distribution of air through the fuel bed and, with strongly coking coals, large dense pieces of coke are produced which have much less reacting surface than was possessed by the original coal. In both ignition and combustion of solid fuels, the extent of the reacting surface is an accelerating factor. Poor combustion permits a surplus of fuel to accumulate in the furnace because the rate of feed and the rate of combustion are not in equilibrium, and this produces an unbalanced condition detrimental to continued automatic service. In order to bum strongly coking coals satisfactorily in a conventional stoker during the three requisite types of operation—continuous, intermittent and hold-fire, frequent attention is necessary. Domestic stokers are defined by the industry as residential stoker heaters that burn 60 lb. of coal or less per hour. With a few exceptions, these units employ the underfeed principle of combustion in which both air and coal move in the same direction up and through the fuel bed. Domestic combustion equipment has difficulty in meeting the problems presented by the several variations in ash and volatile matter, in ash-clinkering tendencies, in coking properties, and in the particle size of bituminous coals. The work of Bituminous Coal Research Inc. at Battelle Memorial Institute has shown that, of these, coking characteristics and the clinkering tendencies have the greatest effect upon the operation of the conventional clinkering type of stoker. Typical coke formations in a clinkering type of underfeed domestic stoker are illustratcd in Fig. I, which shows (A) the ideal fuel bed obtained with a noncoking or free-burning coal; (B) the type of fuel bed formed with a coal that produces a weak coke; and (C) the type of fuel bed obtained with a strongly coking coal. C is characteristic of the fuel bed developed when the average Pennsylvania bituminous coal is burned in an underfeed stoker of conventional type. It is apparent from these pictures that the formation of coke trees will seriously interfere with the efficient automatic combustion of Pennsylvania bituminous coals.

Jan 1, 1942

By Alton B. Cook, G. B. Spencer, F. P. Bobrowski

In estimating production gas/oil ratios and oil recoveries from reservoirs containing highly volatile oils it is highly important to include condensate that may be recovered from the gas produced from the reservoir. The volume of the hydrocarbon liquid condensed from the production of the solution gas that has been liberated. in some reservoirs may equal or even exceed the volume of recoverable stock-tank oil as estimated by present methods. The usual procedure1, 2, 3 in estimating future reservoir performance includes use of relative permeability data of the reservoir rock to gas and oil and includes material-balance calculations utilizing data on the volume of the reservoir fluids, oil and gas production and reservoir pressure decline, and data on the physical properties of the initial reservoir fluids. The inaccuracy in the procedure results from the false assumption that all of the free or liberated gas that enters the well bore of reservoirs containing highly volatile oils remains in the gaseous phase as it is produced. This paper presents a method for estimating future reservoir performance and oil recoveries based on special labora. tory analyses of reservoir-oil samples and recognition of the additional volume of hydrocarbon liquid that will be recovered at various stages of depletion from a solution.gas.drive reservoir. The method also includes calculations of the volume and composition of the hydrocarbon liquids that can be recovered by processing the produced gas in a natural-gasoline plant. The development of the method resulted from a study of laboratory analyses of reservoir samples and of field data obtained from two reservoirs containing oil of the highly velatile type. Relatively high pressures and temperatures prevail in oil reservoirs discovered at the greater depths of present-day drilling. The contained fluids may have high saturation -Dressures and large volumes of gas in solution. The oils and gases under these conditions may be almost identical in compositions and densities.4,5 Also, engineers have noted that, for a number of oil reservoirs and especially the deeper reservoirs, the API gravity of the stock-tank oil increaees as the production gas/oil ratios increase. They attributed this increase in API gravity of the stock-tank oil to the formation of condensate as the liberated gas in the reservoir is being produced. SOURCE OF DATA FOR CALCULATIONS Subsurface oil samples and well-test data were obtained from the E. Constantin-Lambert Well No. 1 in the Elk City Field, Okla., to demonstrate the need for and a method of calculating future reservoir performance when consideration is given to the recoverable hydrocarbon liquid from the production of solution gas that has been or will be liberated in a reservoir. The Lambert well is located in C, SW 1/4, SW 1/4, Set- 18, T-l0-N, R-20-W, Washita County, Okla. At the time of completion it was on the east edge of the development and Was producing from conglomerate through 30 perforations in the 5 1/2-in. casing at a depth of 9,859 to 9,864 ft. The well Was completed on July 9, 1949, and subsurface oil samples were obtained July 29 and August 1, 1949. Production gas/oil ratio data were obtained during the operation in series of two Separators at high and low-pressures of 314 and 44 psia, respectively, and at an average temperature of approximately 60°F. The flowing bottom-hole pressure at the time of sampling was 3,934 psis. The static bottom-hole pressure was not obtained at the time of sampling, as the well could not be shut in long enough for testing because gas produced from the well was used for fuel at an offset drilling well. However, the initial reservoir pressure was calculated to be 4,364 psia from knowledge of pressure gradients in other wells in the field and the depth of the casing perforations in the Lambert NO. 1 well.

Jan 1, 1951

By John Johnston

When I was honored by being invited to give the Howe Memorial Lecture, I decided to read Howe's book, "The Metallography of Steel and Cast Iron," published in I9I6—that is, about 25 years ago—in search of a text. I found the book written in fine, clear, attractive, yet precise style, as I expected, knowing that his father— Dr. Samuel Gridley Howe, his mother— Julia Ward Howe, and all of his four brothers and sisters had lived in a New England literary atmosphere and had written books. This leads me to suggest that many authors of metallurgical papers and books could well study Howe's writings with a view to the improvement of their own. I failed to find a specific text, but did find a subject, for in reading his book I was struck by the few instances in which time is considered explicitly as a factor in the phenomena examined, and by the fact that many of the hottest arguments would have been settled had time been taken properly into account. Indeed, Howe hardly mentions time except in a rather incidental way, as in a few references to lag; for instance: The lowering of temperature at which the transformation occurs by rapid cooling . . . is a phenomenon of undercooling or lag. It is in part explained by the fact that the transformation itself is a time-consuming reaction which, setting in during a rapid fall of temperature, is naturally protracted till the temperature has sunk far below that at which it is due. He does discuss, quite fully, the iron-clrbon equilibrium diagram, as known at that time, introducing it by stating: As he is a reasonable man who is not deterred from using a hand truck for moving his trunk by the consideration that he has thus to move a trunk plus a truck, so am I reasonable in putting into your hands this useful, indeed indispensable. tool for mastering the ABC of iron metallurgy. Somewhat later, in introducing a discussion of the phase rule, which "it would be hardly proper to pass ... by without an attempt to outline its meaning," for "a clear exposition of its applicability or jurisdiction is needed to restrain the half-initiated from misusing it and the uninitiated from being misled by these misuses," he writes—and I quote his statement because we cannot properly discuss the influence of time on a process until we know the state of equilibrium which would ultimately be reached by the system under consideration: It is a most remarkable and valuable generalization, its conceptions help greatly toward getting a broad outlook on metallography, but its misconception has brought out a flood of obscuring writings. it tells us about the constitution towards which alloys tend, that which they reach when equilibrium is complete, when all tendencies have corrected themselves and have been complied with completely. Its application, in absence of true equilibrium, is like determining density with a telescope or even with a tuning fork; it is like the mad tea party at which the butter put into the works of the watch was the best butter. If the reader learns no more than to beware of attempts to dccipher the conditions of inequilibrium by a law which touches only the conditions of exact

Jan 1, 1942

By Robert A. Colten, Frederick C. Hull, Robert F. Mehl

It is known that pearlite forms from austenite by a process of nucleation and growth, and that the rate of formation of pearlite may be described by a rate of nucleation and a rate of growth.l,2 The manner in which these two quantities operate to produce the observed isothermal reaction curve has been analyzed in a paper published in I939.3 Two types of process were described: (I) that in which nucleation occurs at the grain boundaries of the parent phase, with the nodules growing toward the centers of the grains, initially as hemispheres and then after impingement as roughly radial-columnar structures; and (2) that in which nucleation occurs generally, with the nodules growing to full spheres until impingement with other growing nodules restricts growth. Both cases are met in the formation of pearlite from austenite (Fig. I);2,4 the former, occurring near the knee of the S-curve, has been named "grain-boundary transformation," and the latter, occurring at temperatures near Ael, has been named "group-nodule transformation." In developing our knowledge of the factors that determine the rate of formation of pearlite from austenite, it is important1,2 to obtain data on the rate of nucleation and the rate of growth of pearlite. Such data, when obtained near the knee of the S-curve, will furnish information of use in understanding the factors that affect hardenabil-ity; when obtained at higher temperatures, such data will be useful in understanding the behavior of steels that during heat-treatment react to pearlite.2 It is the purpose of this paper to present data on the rate of nucleation and the rate of growth of pearlite in dependence upon composition, grain size, temperature, and the degree of homogeneity of the parent austenite. The studies are restricted chiefly to plain carbon commercial steels." Previous Data on Rate of nucleation and rate of Growth Data on the rate of nucleation and the rate of growth of pearlite have been published by Scheil and Lange-Weise,5 by Mirkin and Blanter,6,7 by Meh1,l and by Dorn, De Garmo and Flanigan.2, It is difficult to interpret the data, for in most cases too little information is given on austenitizing temperatures and times, the state of homogeneity of the austenite (presence or absence of carbide, etc.), austenite grain size, and mode of formation of pearlite at the temperatures given. Except for the approximations of Mehl and the work of Dorn, austenite grain size was disregarded, though it is well known

Jan 1, 1942

By R. A. Morse, W. O. Keller

The properties of limestone reservoir rocks such as the distribution and degree of continuity of the pore systems, and the relative volumes and permeabilities of the systems making up the complex cause large variations between performance of individual limestone reservoirs and their susceptibility to secondary recovery methods. The effects of these factors on the mechanism of fluid flow cannot be adequately evaluated with presently developed concepts, laboratory data, and geological information. The observance and interpretation of the performance of individual limestone reservoirs provides, at present, the most adequate approach for evaluating the integrated effects upon performance of the many. now immeasurable variations in the properties of limestone reservoirs. INTRODUCTION The development and application of techniques for increasing the efficiency of oil recovery from natural reservoirs is a problem of primary importance to the industry. During the past several years, a great deal of effort has been expended by the technical personnel of the industry toward the improvement of present known methods of oil recovery. and evaluating the factors which control the susceptibility of particular reservoir types to economic application of secondary recovery methods. Providing adequate and accurate laboratory data on the properties of the reservoir rock and its contained fluids. together with good production statistics, are available, methods have been evolved for estimating with reasonable accuracy the performance of an oil reservoir under either continued natural depletion or conditions imposed by introducing additional displacing fluid into the reservoir from an extraneous source through the injection of gas and/or water. The susceptibility of limestone reservoirs to secondary recovery by gas injection is very much dependent upon gas-oil relative permeability relationships for the reservoir in question. In a rock formation in which the porosity is of the intergranular type such as is found in sand stones and some non-fractured dolomites, a representative sample of the pore structure can be obtained in a small core plug. In this type of reservoir, it has been shown that relative permeability data obtained from laboratory experiments can be Properly applied to evaluate the flow relationships actually observed during the depletion of a reservoir. In addition, a good idea of the fraction of the reservoir which will be swept by the injected gas may be obtained from the spacing pattern used and the permeability profile of cored wells. From these data, it has been demonstrated that reliable estimates of performance and recoveries under gas injection operations can be made for reservoirs in which the Porosity is of the intergranular type. Limestone reservoirs on the other hand often present much more complex problems. One reason that the performance of limestone reservoirs is so variable is that there may be, in reality. two or more pore systems, the integrated performance of which will depend upon the physical properties of each system and their inter-relationship. For instance, in a limestone reservoir, the main pore structure, as far as void spaces for storage of hydrocarbons is concerned, may be represented by the intergranular openings of the rock. Usually in limes and dolomites, the intergranular pore openings are very small and the matrix permeabilities extremely low. Often, as in the case of Many dolomite and oolitic lime reservoirs, this is the only pore system, and performance is observed to be very similar to that of a sand stone of similar permeability. However, in the great majority of' the limestone reservoirs, there is present, in addition to the intergranular pore system, a complementary system of openings caused by fracturing or solution.',' The openings in the latter system are usually many times more permeable than the intergranular pore system due to their much larger size, and may contribute almost all the fluid carrying capacity of the formation, even though their volume may be a very small part of the total pore space in the reservoir. Obviously, the performance of such a complex under either primary or secondary control will deend upon the distribution and degree of continuity of both systems, the relative volumes and permeabilities of the

Jan 1, 1949

By P. W. George

This paper presents geological data regarding deposits of over 7,500,000 tons of fine-grained sulphide ore in barite gangue. A series of pyroclastics and arkoses was intruded by sills of quartz porphyry in connection with batholithic intrusions of granite 3 miles from Buchans. Gentle folding, with fracturing and shearing of tuff beds and intruded quartz porphyry, accompanied and followed the intrusion of granite and porphyry. The sulphide-barite mineralization is localized primarily in fractured and sheared tuff beds, but also in the sheared quartz porphyry. Two structures have proved particularly favorable for mineralization-one, the center of an anticline; the other, a series of weak, incompetent tuff beds intruded by thin sills of quartz porphyry and located between strong beds of arkose. During the folding the weak tuff with intruded quartz porphyry was intensely sheared and contorted and subsequently mineralized by sulphides and barite. INTRODUCTION Buchans is 5 miles north of Red Indian Lake, in Central Newfound- land, at an elevation of 900 ft. above sea level and 400 ft. above Red Indian Lake, and is reached by a 37-mile private railway from Miller- town Junction. The first ore body found at Buchans was discovered some 30 years ago in the bed of Buchans River, by Matty Mitchell, an Indian woodsman employed by the Anglo-Newfoundland Development Co. Ltd. In the years following the discovery the ore was developed by shaft-sinking and drifting, with results indicating a lenticular ore body in a shear zone, containing about 100,000 tons of extremely fine-grained sulphide ore in barite gangue averaging about 0.05 oz. Au, 4 oz. Ag, 1.5 per cent Ch, 10 per cent Pb, 18 per cent Zn. Because a profitable metallurgical treatment for the ore was not found, the mine was closed down in 1911. In 1915, Mr. H. A. Guess, Vice President of the American Smelting & Refining Co., learned of the Buchans River ore body, and after metallurgical tests had been carried on from time to time in his company's testing plant a satisfactory separation of the sulphides by selective flotation was finally effected in 1925. Prospecting for additional ore bodies was begun in 1926, utilizing geophysical methods under the direction of Hans Lund-

Jan 1, 1937

By L. K. Jetter, J. C. Ogle, C. L. McHargue

The preferred orientation developed in extruded aluminum rods has been studied as a function of extrusion temperature, extrusion speed, and position in the rod. Duplex <111> - <001> textures were developed for slow extrusion speeds at temperatures of 75° to 850° F and for fast extrusion speeds at temperatures of 75° to 450°F. The <001> texture component was shown to be primarily due to re crystallization occurring during fabrication. At fast speeds and billet temperatures of 650° to 850°F, complete recrystallization occurred and <115>or<118> textures were found. The nature of the structure has proved to be an important variable in the production and use of extruded products. Data on the flow of aluminum and aluminum alloys summarized by Smith,&apos; Hardy,&apos; and Locke3 show that the extruded product may possess a deformed, a partially recrystallized, or a completely recrystallized structure, and there may be important variations in the structure from surface to center and from front end to back end of an extrusion. This inhomogeneity in grain structure and preferred orientation affects both the mechanical properties of the extruded section and its response to subsequent heat treatment. Among the fabrication variables causing these differences are temperature, extrusion ratio, and extrusion speed. Preferred orientation which develops during the extrusion of rods is of the fiber-type and, in general, has been assumed to be similar to that developed in rods or wires fabricated by drawing through dies, rolling, or swaging.4 Because of the nature of the flow of metal being extruded, this assumption may be valid for material near the center of the rod but probably is not valid for the outer layers. In most face-centered-cubic metals a duplex fiber texture has commonly been reported in which the grains have either <Ill> or <001> directions parallel to the longitudinal axis. Sachs and fichiebold5 reported cold-drawn aluminum (99.6 pct pure) to have a single <Ill> fiber texture, and this observation was confirmed by Schmid and Wassermann.6 Hibbard, on the other hand, observed a minor <001> and a major <111> texture in 99.994 pct A1 cold drawn to 98 pct reduction in diam.7 He concluded that the <001> component resulted from a small amount of room-temperature recrystallization. Dayal8 concluded that the <001> component was an intermediate component which disappeared at high reductions in 99.5 pct pure Al. Kostron and schippers9 found duplex <111> — <001> textures in extruded 99.5 pct Al, as did Gow and cahnl0 and GOW11 for extruded rods of commercial and superpure aluminum. Similar duplex fiber textures have been reported for aluminum alloys by Kostron,= Unckel,13 and Van Horn.14 The present paper is concerned with the variation in texture with fabricating conditions and with the nature of the texture components in extruded aluminum rod (99.99 pct pure). EXPERIMENTAL PROCEDURE Ingots were chill-cast in cast-iron molds and machined to 3-in. diam by 6-in. long extrusion billets. These billets were upset to 3.125 in. diam and extruded through a flat-face 0.690-in. diam die. Quenching of the rods was accomplished by a water spray at the die face. The combinations of fabricat-

Jan 1, 1960

By C. W. Lawr

The ores mined by the Santa Gertrudis Co. at Pachuca, Mexico, arc mainly silver-bearing; they also yield some gold and carry a little copper. Strong cyanide solutions are used to dissolve the silver and gold, and the mechanical loss of cyanide at the tailings filter has been considerable. Prior to the year 1923, the pulp, after agitation, was given a 35 to 37-min. wash with barren solution in a Butters-type leaf filter; the discharged slime cake was repulped and pumped into eight Merrill self-sluicing slime presses in which the slime was given a further wash with barren solution for 25 to 35 min., followed by a 10-min. water wash. At that time the barren solution titrated around 0.350 per cent. free KCN and 0.500 per cent. total KCN. (Aero brand cyanide is used.) It can readily be seen that a 10-min. water wash would leave considerable cyanide in the filter cake, which of course was a total loss. This averaged 0.522 kg. (1.15 Ib.) KCN per ton of solution. As the daily discharge to the dam was 1600 tons&apos; of slime of a 2:1 ratio of liquid to solid, the value of this mechanical loss of cyanide was an important item and it&apos;s recovery held alluring possibilities. Principle of Cyanide-recovery Process As it had acquired the patent rights to theLayng (H. R.) and Halvor-sen (A. L.) processes, also those of Mills (L. D.) and Crowe (T. B.) after considerable experimental work in its own laboratory and at Tonopah, Nev., The Merrill Company of San Francisco early in 1923 notified the Mexican Corporation and compania de Santa Gertrudis of its process for the recovery of cyanide from weak wash solutions, or for the transference of cyanide from a foul mill solution to a clean alkaline solution. This method is known as the Mills-Crowe process, the principle of which is as follows: The solution from which the cyanidc is to be removed is made acid by bringing it into contact with sulfur dioxide (SO2). The acidified solution is the; transferred to a closed tank in which air and solution are brought into intimate contact. The air leaving the tank charged with HCN is then passed to another tank in which it is mixed with an alkaline solution,

Jan 1, 1930

By G. K. Manning, C. H. Lorig

TWO metallurgical tools have acquired wide use within the past several years as a means of studying the transformation characteristics of steel. One is a technique used first by Bain and Davenport for determining the transformation characteristics of a steel at constant temperature; the second is the end-quench hardenability test. Constant-temperature transformation curves like those of Bain and Davenport have done much to rationalize the metallography of steel; however, in commercial practices, constant-temperature transformation is seldom encountered, therefore only rarely can such curves be directly applied. The real reason for the determination of such curves lies in the fact that they provide a way of thinking about transformation that is both convenient and productive. The end-quench hardenability test is a more practical means of studying transformation, for, by correlating positions on the hardenability bar with shapes of different masses, an almost direct application of the results can be made. Unfortunately, the end-quench test, though practical, can do very little toward improving the metallurgists&apos; way of thinking about transformation. These two metallurgical tools, dealing with precisely the same phenomenon, should be very closely associated in metallurgists&apos; minds. Actually, they are frequently pushed into separate mental corners and considered as being more or less distinct and unrelated. The reason for this is that no strong connecting link between them has been developed. An attempt is sometimes made to relate these two tools by projecting the critical cooling rate on the isothermal transformation plot as illustrated in Fig. I. The critical cooling rate is considered as a constant rate-though in practical applications, cooling rates are never constant—and this constant cooling rate is given uniform significance from the Ae temperature down to the temperature of initial transformation. A little thought indicates the errors of such a procedure. Certainly the time interval spent just below point A of Fig. I cannot be as effective in promoting nucleation as is the time interval spent just above point B. Yet the procedure represented in Fig. I considers all the time spent between temperatures A and B to be just as effective in promoting nucleation as though all the time were spent at temperature B. Furthermore, change the shape of the isothermal curve between points B and C in any way desired, and the required critical cooling rate is not changed one iota. This cannot possibly be true. Such a way of thinking about critical cooling rates not only is incapable of giving any results that are quantitatively satisfactory but is likely to give very misleading qualitative results.

Jan 1, 1947

By M. C. Dow

Belt conveyors generally are conceded to be the most economical method yet devised for the transportation of large quantities of bulk materials within plants. Belts are coming into greater use for transportation over long distances and are replacing other forms of long-haul conveyance. It is not the intent of the writer to comment on the design of belt conveyors, but to offer some suggestions for improvement in the operation of conveying belts, based on many years experience with belts in several stone-crushing plants. It is the contention of this writer that opportunities for improvement not fully realized by most operators exist in many plants and that a study of the individual conveyors can result in lower unit belt costs. General Reliability It is the fool-proof nature and general reliability of the belt conveyor that is responsible for its neglect. Even when abused, a belt will carry large tonnages and last a long time, often outlasting the personnel responsible for its care. Some operators look upon the purchase of a new belt as an expensive outlay every so many years, rather than a constant and steady cost amounting in belt wear alone to several dollars every operating day. This belt wear for all conveyors in one stone-crushing plant known by the writer costs 1 /12 cents per ton or $12 to $15 per hour, based on the present cost of belt replacements. The fact that these replacement costs are double those of prewar quality emphasizes the necessity of improving the conditions that make belts wear out. Some of those conditions are the responsibility of the conveyor designer, and if a serious original error has been made, this handicap cannot be overcome by the operator. If the belt is too narrow, too steep, or too fast for good loading, the operator finds that he has an inherently expensive belt. The other factors that decrease the life of a belt are more or less under his control. The two factors of most importance are the loading conditions and the alignment. Most of the cover wear and carcass cutting occurs at the loading point and if the alignment is not good under all conditions, edge wear or damage may result, Fig I. Loading the Belt It is difficult to load a belt in an ideal manner; that is, to flow the material on the moving belt at a steady rate, without impact, without turbulence, and with a velocity equal to and in the same direction as the belt. An inclined belt is especially difficult to load and particularly when its speed is over 300 or 350 fpm. Inclined conveyors require longer skirt plates to prevent spillage until the load settles. It does not seem reasonable to expect an inclined the to carry the same load as a horizontal belt of the same width and speed, because of the difficulty in loading

Jan 1, 1948

By J. L. Gillson

In a brief summary of the many occurrences of fluorspar in our western states, it is not possible to go into detail in regard to the geology, mining and milling methods, and reserves about individual deposits. Rather a broad review is made of the occurrences and an analysis of how the western deposits may fit into our future domestic economy is presented. General Statement on Fluorspar Situation Fluorspar has been used for years as a flux in the manufacture of basic open-hearth steel, in foundry cupolas for melting pig iron, in the manufacture of opalescent glass and in the preparation of hydrofluoric acid. In 1880 the annual production of fluorspar in the United States was around 4000 tons per year. By 1900 it was up to 21,656 tons and between 1902 and 1908 it averaged about 40,000 tons annually. Prices were then so low, by present standards, that it seems impossible to believe now that mining could have been performed profitably at the price levels then prevailing. In 1890 fluorspar sold at the mines for $6.70 per ton, in 1901 for $5.81, in 1916 for 85.92. When the United States entered World War I, flyorspar production and price skyrocketed; the production reached 263,817 tons in 1918, with prices above $20.00 per ton, and prices were even higher in 1919 and 1920. After 1920, the domestic production fell from the 1918 level to about 125,000 tons annually and the average price dropped back to about $18.00 per ton. By 1935 the average price had fallen to $15.00, but in 1940 with a rising demand the average price of all grades had gone back up to $20.31. Today it is 75 per cent higher than in 1940 and presumably the price of acid grade at .least would be even higher if it were not for price ceilings. The first subsequent year that the domestic production exceeded that of 1918 was 1941, and the 1944 production is expected to exceed 400,000 tons, or over one and a half times that of 1918. In five-year periods, average production and imports were as are shown in Table I. Many people concerned with the consumption of fluorspar believe that the postwar period ahead will show a repetition of price trends of the last such period. They believe that imports will be again an important factor in the available supply and the price will fall back gradually toward the prewar level. The following basic factors are pertinent in analyzing this conclusion:

Jan 1, 1948

By F. W. Bremmer

The experiments described in this paper constitute the preliminary work of an investigation outlined to determine the combined effects of steam and temperature on the endurance properties of certain steels. Essentially of a fundamental nature, it was found necessary, in order to make the investigation comprehensive, to test materials treated to give a wide range of properties. The work reported deals chiefly with nickel steel with one series of tests including nitriding steel. Such a study involves numerous variables, and requires an endurance-testing machine of rather special design. Testing Machines The testing machines used were designed by C. E. Weaver;l they are a modification of the White-Souther and McAdam types. Each was driven directly by an individual 1/2-hp. 115-volt direct-current motor, running at a speed of 2200 r.p.m. Fig. 1 shows the assembly drawing and Fig. 2, a photograph of one of the machines. Specimen B is held by the rotating specimen holder A inside the steam box F, which is closed at the top by a tight-fitting, elliptical cover G. The load is applied to the specimen through the rod D and bearing C. E is an oil pipe leading fromthe lubrication system to the bearing C. The steam, which comes from the power house, is admitted through an inlet (not shown in Fig. 1) at the side of the box, the drain being at the bottom. Steam packings were placed around the rod D and the rotating shaft at H, from which the water was drained by means of a vacuum, which usually showed a gage reading of about 10 in. The temperature was measured by a mercury thermometer, and the pressure by a steam gage. Method of Applying Load After the motor has been started and the specimen as a consequence put in rotation, the load is applied by placing the foot pedal A (Fig. 2) in contact with electromagnet B, the winding of which is connected electrically in series with the motor. This operation releases the support under the weights that constitute the load. By this means the load

Jan 1, 1930

By Alfred H. Bell, George V. Cohee

In 1941 Illinois produced 134,139,000 bbl. of oil, or 9.5 per cent of the total for the United States, and ranked fourth among the states. The production for 1941 declined 9.2 per cent from the previous year&apos;s total of 147,647,000 bbl. Daily average production for 1941 was 366,000 bbl. At the beginning of the year daily production was slightly more than 326,000 bbl. and it remained at appoximately that amount until June, when there was a slight increase. The increase continued until the peak of 431,260 bbl. daily was reached for the week ending Oct. 4. Daily average production at the end of the year was approximately 387,500 barrels. The increased production during the last half of 1941 was largely due to the rapid development of the Johnsonville field, Wayne County, the Rural Hill field, Hamilton County, and the Benton field, Franklin County—new fields discovered in the current year (Fig&apos; 1)—and the Woodlawn pool, discovered in 1940. Discoveries In 19 counties in southern Illinois, 44 new fields were discovered in 1941 (Fig. 2 and Table 2), and extensions to 40 fields were successfully completed (Table 3). At the end of the year there were 10,496 wells in the fields discovered since Jan. I, &apos;937, as compared with 71965 wells at the end Of &apos;940. The area proved for production in the new fields increased from 78,040 acres at the beginning of 1941 to 97,483 acres at the end of the year (Table I)—an increase of 19,433 acres, of which 9,955 acres are in the fields discovered during the current year, and the remainder of 9,478 acres in extensions to pools discovered earlier. Drilling During the past year, 3838 wells were completed in Illinois (Table 4), of which 2912 were oil producers, 13 were gas producers and 913 were dry holes; 76 per cent of the wells drilled were producers. Of the total number drilled, 591 wells are classified as "wildcat" and of these 84 (1 in 7) were successful in obtaining production. The results of an investigation to ascer-tain the reason for the locations of the wildcat wells are set forth in Table 5. Of the 591 wildcat wells, the 292 known to have been located by scientific methods were 21.6 per cent successful. The total footage of wildcat wells drilled in 1941 was 1,341,743 ft., of which a total of 216,995 ft. was drilled in successful wells. Exploration MEthods Subsurface geology and geophysics, largely the reflection seismograph, are still the principal methods used in exploration and development in the state. The number of seismograph parties operating throughout the year was as follows: seven parties on Jan. I, 1941; five on Apr. I; four On July I; eight on Oct. I; fifteen on Jan. 1: 1942.

Jan 1, 1942

By Nicholas J. Grant, David S. Bloom

An investigation of the Cr-Ni system has revealed that there exists a eutectoid transformation at about 1180°C. &apos;The transformation in chromium implied by the eutectoid reaction was detected at about 100°C below its melting point. Associated with the eutectoid transformation, a metastable transition structure has been found. THE Cr-Ni phase diagram is shown in current literature to be a simple eutectic system in which the high chromium end of the diagram is incompletely determined, Fig. 1. The last investigation of this system was undertaken in 1936.&apos; Because of limitations in metal purity, especially of chromium, and temperature measuring techniques, the diagram should be accepted with some reservations, as was indicated by Hansen.V or examwle.-, the wresence of the compound Cr²Ni, with a tetragonal structure," remains unverified and incompatible with the simple eutectic diagram. The work reported here began because of discrepancies that appeared in experimental studies in the binary alloys Cr-Ni and in the ternary system Cr-Mo-Ni. The existing binary Cr-Ni diagram failed to provide a complete explanation of observations made by microscope, X-ray, and thermal analyses. Experimental Methods The materials employed were of a higher degree of purity than were available to previous investigators. The Mond nickel used had a nominal purity of 99.87 pct, while the electrolytic chromium analyzed 99.03 pct with the major impurity being 0.5 to 0.7 pct oxygen with some iron. All alloys were melted in a vacuum furnace to remove dissolved gases, sufficient carbon was added to the charge to combine with all the oxygen as CO. Final analysis determined the carbon as about 0.02 pct and the oxygen around 0.06 pct or slightly more. Stabilized zirconia crucibles and thermocouple protection tips were used throughout and contributed no detectable impurity to the melts, as long as the oxygen in the chromium was kept low. Heats averaged about 250 g, which permitted about 2 in. of the thermocouple protection tips to be submerged. The temperature drop across the thermocouple protection tip was determined to be about 3°C, a minor source of error. The alloys, after removal from the vacuum furnace, were placed in a furnace operating in a purified argon atmosphere for the thermal analyses. An- nealed wolfram-molybdenum thermocouples provided the primary means of temperature determination, though a Pt-Pt-10 pct Rh couple was employed for a check when possible. A sensitive, high-speed Leeds and Northrup Speedomax recording potentiometer indicated the thermocouple output. X-ray diffraction patterns were obtained primarily on a Norelco unit, which permitted diffraction angles only up to 45" (28 = 90"). In general, either rotated or stationary solid samples were used, because it later evolved that many samples were susceptible to transformation resulting from the cold working involved in pulverizing. It was also noted that rotating a sample sometimes suppressed weak lines, so, usually, samples were not rotated. Later a high temperature camera was adapted for use at temperatures up to 1400 °C on the Norelco unit utilizing both solid and powdered samples. Unless otherwise noted, all X-ray patterns were made with a chromium tube and a vanadium filter. Further-

Jan 1, 1952