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By George Stone

THE stack gases from regenerative furnaces are very seldom utilized for the production of steam. If the temperature of the gases is not higher than 300° C. (572° F.) there is no economy in their use for this purpose, as the amount of available heat is very small and the temperature is so little above that of the steam that the interchange is too slow. With higher temperatures of the waste gases, however, good results can be obtained. At the plant of the New Jersey Zinc Co. (of Pa.) at Palmerton there are a number of return tubular boilers, each 6 ft. in diameter and 20 ft. long, with 96 3.5-in. tubes, which are heated by the waste gases from the spelter furnaces. These furnaces have continuous regenerators heating the air only and the stack gases reach the boilers at a temperature of about 450°. The gas producers for one of these furnaces require 14 tons of anthracite (a mixture of Nos. 2 and 3 buckwheat), and the waste heat from the furnace gives a little more than 42 h.p. in steam. The boilers are not well adapted for the purpose, as they are much too large for the amount of heat going to them and the area of the tubes is not sufficient to take the gas from two furnaces without causing an objectionable amount of back pressure. The plant was built without any idea of using waste-heat boilers, and it was impossible to place the latter as close to the furnaces as they should be. Furnace and boiler are connected by an underground brick flue in which the temperature of the gas drops about 100°, losing 40 per cent. of its available heat. If the .boilers were close to the furnaces the horse power of each would be 70 instead of 42. Even under these unfavorable conditions the boilers have been very advantageous, as one boiler easily supplies the steam necessary for two batteries of producers. With such low gas temperatures the heating surface of the boilers is, of course, not as efficient and the flue areas need to be considerably larger than for coal firing.

Jan 10, 1913

By George C. Stone

The stack gases from regenerative furnaces lare very seldom utilized for the production of steam. If the temperature of the gases is not higher than 300" C. (572" F.) there is no economy in their use for this purpose, as the amount of available heat is very small and the temperature is so little above that of the steam that the interchange is too slow. With higher temperatures of the waste gases, however, good results can be obtained. At the plant of the New Jersey Zinc Co. (of Pa.) at Palmerton there are a number of return tubular boilers, each 6 ft. in diameter and 20 ft. long, with 96 3.5-in. tubes, which are heated by the waste gases from the spelter furnaces. These furnaces have continuous regenerators heating the air only and the stack gases reach the boilers at a temperature of about 450". The gas producers for one of these furnaces require 14 tons of anthracite (a mixture of Nos. 2 and 3 buckwheat), and the waste heat from the furnace gives a little more than 42 h.p. in steam. The boilers are not well adapted for the purpose, as they are much too large for the amount of heat going to them and the area of the tubes is not sufficient to take the gas from two furnaces without causing an objectionable amount of back pressure. The plant was built without any idea of using waste-heat boilers, and it was impossible to place the latter as close to the furnaces as they should be. Furnace and boiler are connected by an underground brick flue in which the temperature of the gas drops about 100°, losing 40 per cent. of its available heat. If the boilers were close to the furnaces the horse power of each would be 70 instead of 42. Even under these unfavorable conditions the boilers have been very advantageous, as one boiler easily supplies the steam necessary for two batteries of producers. With such low gas temperatures the heating surface of the boilers is, of course, not as efficient and the flue areas need to be considerably larger than for coal firing.

Jan 1, 1914

By D. W. Fuerstenau

MEASUREMENT of zeta potentials is a useful tool to study the surface chemistry of minerals under flotation conditions.1,2 Because there is continued interest in this approach, the apparatus for obtaining zeta potentials of nonconducting solids by the streaming potential method is outlined here. Fig. 1 illustrates the streaming potential apparatus." The streaming potential cell or plug consists of two 24/40 standard ground joints (4) joined with a piece of pyrex tubing 60 mm long and 12 mm in diam (5). The electrodes are made of bright platinum disks 19 mm in diam and 1 mm thick through which 0.5-mm holes have been drilled (6). To the surface of each is welded a piece of 80-mesh platinum gauze. Each electrode is permanently mounted on the ends of the inner parts of the two standard joints by means of a platinum wire (7) which connects it to the tungsten seal at the end of the cell (8). For ease in cleaning and handling the apparatus, the streaming cell is fastened to the 500-ml reservoir flasks (1) by means of two 18/9 ball and socket joints (2). This particular arrangement permits passage of the solution in either direction through the plug of particles. Flow of solution can be stopped by a stopcock (3). One of the reservoir flasks has a large opening to permit insertion of either a thermometer or a pair of electrodes for measuring pH of solutions within the system. In making the experiments, the plug is filled with 48 to 65-mesh particles, but a layer of 28 to 35-mesh particles is placed at each electrode to prevent any of the finer particles from passing through holes in the electrodes. The assembled apparatus is shown schematically in Fig. 2. To eliminate CO2 from the solutions, all experiments are conducted in a nitrogen atmosphere. Nitrogen, used to drive solutions through the plug, is passed through a bottle of concentrated KOH solution to remove CO2 (9). A 9-liter ballast reservoir (10) is used to maintain a more nearly uniform pressure. A series of stopcocks controls the direction of flow nitrogen to the flasks (11). Tubes of as-carite prevent backflow of CO2 into the system (12). Driving pressure, which can be set at any desired value, is measured with either a water manometer (13) or a mercury manometer (14). Reservoir flasks have side arms for making pressure corrections for the difference in water levels in the flasks. Streaming potentials are measured by the circuit illustrated in Fig. 2. The electrodes from the plug are connected through mercury wells (15) to a reversing switch (16), which reverses the polarity of the electrodes depending on the direction of flow of solution through the plug. The streaming potential is measured with a Leeds and Northrup type K2 potentiometer (17). Proper choice of null instrument is important because Eq. 1 assumes that the current which escapes through the measuring instruments is negligible. An ordinary galvanometer cannot be used to determine the null point because

Jan 1, 1957

By Geo. Otis Smith

Twelve years ago, the Director of the United States Geological Survey addressed to the Secretary of the Interior a letter calling attention to the government's need for liquid fuel for naval use and pointing out that the rate of increase in demand was more rapid than the increase in production.' This letter, in a way, inaugurated the policy of public oil-land withdrawals, which was well founded in its primary purpose of protecting the oil industry and highly desirable in its immediate effect of checking the over-development of that day in California. Unfortunately, however, through delays in legislation, this policy may be regarded now as having outlived both its intent and its usefulness. In 1908, the country's production of oil was 178,500,000 bbl., and there was a surplus above consumption of more than 20,000,000 bbl. available to go into storage. In 1918, 10 years later, the oil wells of the United States yielded 356,000,000 bb1.—nearly twice the yield of 1908—but to meet the demands of the increased consumption more than 24,000,000 bbl. had to be drawn from storage. Nor is this all of the brief comparison. In 1918, our excess of imports over exports of crude petroleum was nearly 33,000,000 bbl. whereas in 1908 we exported 3,500,000 bbl., which was net, as we had not begun to import Mexican oil. In this period, the annual fuel-oil consumption of the railroads alone has increased from 16,871,000 to 36,714,000 bbl.; the annual gasoline production from 540,000,000 gal. to 3,500,000,000 gal. This record may be taken not only as justifying the earlier appeal for Federal action, but as warranting deliberate attention to the oil problem of today. Need of Future Supply The position of the United States in regard to oil can best be characterized as precarious. Using more than one-third of a billion barrels a year, we are drawing not only from the underground pools but also from storage, and both of these supplies are limited. In 1918, the contribu-

Jan 1, 1921

By C. L. HUNTZINGER

THE mine here described is in the Witbank district, a coal area of the Transvaal, about 100 miles north- east of Johannesburg. and is owned by the Witbank Colliery, Ltd. The plant has a capacity of 4000 tons per eight hours, and prepares five sizes of coal. The coal seam lies at a depth of about 200 ft. below the surface, and is reached by an inclined shaft sunk at an angle of 18° with the horizontal. Although the thickness of the coal seam varies from 10 to 14 ft. or more, only about a 7-ft. bench is mined. Mining is by the hord and pillar system. Bords are driven 18 ft. wide, with pillars measuring 18 ft. square. The mine is laid out into four sections, each sewed by a main haulage way from the shaft. Arc-wall machines are used for cutting the coal. but all loading is done by hand. Native labor is employed under the supervision of white miners, who do the required blasting. The workings are practically free from gas and water, and very little timber is needed.

Jan 1, 1931

By John J. Dran

The elaborate analytical techniques for risk analysis used by the large mining companies in conjunction with the valuation of mineral reserve sites are totally inappropriate for the small miner. The small miner does not possess the financial and technical resources which are available to the large companies for such risk analysis. Even if these resources were available to him, the relatively small size of his investment would not justify a huge expenditure for risk analysis. What is required by the small miner is an improvement over the single point estimates provided by the valuation techniques that he currently uses. Such improvement should provide an indication of the extent to which the true value (known only after the fact) might differ from his estimated value of the mineral reserve site. In addition, a rough indication of the chance of occurrence of various differences between the true and estimated values would be helpful to him. These improvements must be obtained at low cost to be useful to the small miner. Such improvements would have to be based on a simple system requiring very few additional estimates by the miner. The small miner is not accustomed to dealing with sophisticated risk analysis techniques. Hence, any complex, time-consuming approach would be doomed to disuse or possible misuse. A simple, uncomplicated approach requiring a minimum of additional estimates by the miner can be based on a system devised by Frederick S. Hillier Although Hillier's method can be applied to various mineral reserve valuation methods used by the small miner, this note is specifically oriented to the discounted cash flow model. The basic discounted cash flow (DCF) approach provides a single point estimate of value and introduces the concept of risk (i.e. the possibility that the annual cash flows may differ from their estimated values and thus lead to an incorrect investment value) through the use of a risk-adjusted discount rate. This approach simply lowers the present value estimate with increases in the discount rate (i.e. increases in the risk assessment). The single point estimate still remains. Although the lower value estimate makes it less likely that the risky investment will be deemed profitable and undertaken, it provides no indication of risk that is suitable for examination and analysis. In addition to the "best guess" estimate of annual net cash flows required in the DCF model, application of the Hillier risk analysis model requires that the miner

Jan 1, 1976

By W. Irwin Moyer

Two methods for the rapid valuation of oil properties are in common use. The one best known and most widely used is the "per barrel" value, based on the present daily production of the well, without regard to its past performance or the history of the sand or pool from which it produces. The second method is the "time to pay out," or the length of time required for a well to place itself upon the credit side of the ledger, from which time the returns from its production (less the operating expenses) will be clear profit. The time basis for valuation is also commonly used in the appraisal of an undeveloped lease. In most oil fields, it is not thought good business to invest in production that will not pay out in at least 4 to 5 years. Nearly all buyers (except in certain regions of very persistent production like the deep-sand territory of the Appalachian field) expect wells to pay out in considerably less time than this. Like the barrel per day price, the time necessary for a well to pay out has been determined for each field, so that one frequently hears a field or district referred to as having a certain time to pay out. This is considered the norm for that field or district and the buyer and seller base their value, to greater or less extent, on their belief in the accuracy of this time. The writer long ago became convinced of the inaccuracy of the barrel per day method, except when greatly modified for local conditions, such as the age of the wells, their economic limit, operating conditions in the field, the future price of oil, and the persistence of the sand as a producer. When so modified, this method becomes more of an analytic or predicted probable yield valuation. While the appraiser may not go through each step in a valuation based on future returnable revenue, his knowledge of the field and the local conditions surrounding his leases make it possible for him to estimate a fair sales value that, in many cases, will be a close approximation to the truth. This is quite different from the commonly understood barrel per day value, in that the conditions surrounding the sale of one lease or property at a fair market value may

Jan 1, 1922

By B. E. Terkelsen, B. J. Piearcey

A study has been made of the effect of unidirectional solidification on the creep behavior, stress-rupture properties, and thermal shock resistance of four nickel-base superalloys. The alloys Mar-MZOO, B-1900, IN 100, and TRW 1900 show improved rupture ductility and thermal shock resistance when tested with the columnar grains parallel to the major stress axis during test. The relative improvement in creep-rupture properties depends on the intrinsic strength of the alloy, a property which depends on composition, heat-treatnient, and crystallographic orientation. The data clarifies some of the factors affecting the properlies of the cast nickel-base superalloy. COMPONENTS designed for high-temperature use have, in recent years, been fabricated by precision casting techniques using nickel-base alloys developed specifically for use in the conventionally cast condition. This development was a result of both the increasing complexity of the component and the recognition that high-temperature strength was incompatible with workability. The use of castings can be economically favorable, but, more important, the recent complex designs of air-cooled gas turbine blades and vanes in alloys which possess the necessary high-temperature strength cannot be forged. Common modes of failure of high-temperature components are excessive creep, creep rupture, and thermal fatigue. If rupture occurs then the mechanism is usually by inter crystalline cracking along those grain boundaries oriented transverse to the major stress axis. In the stronger alloys, rapid propagation of intercrystalline cracks result in apparent premature failure demonstrated by the absence of third stage creep in a creep-rupture test and low rupture ductility. Tensile ductility shows a similar trend, that is, decreasing ductility with increase in strength. It is not surprising, therefore, that increases in creep strength have only been obtained with a loss in resistance to thermal shock, a property which shows a dependence on tensile ductility. VerSnyder and ~uard' showed that the application of unidirectional solidification to a brittle Ni-Cr-A1 alloy both improved the rupture life of the alloy and increased rupture ductility. Since this casting method results in columnar grains, it appeared that the solution to the lack of ductility in nickel-base alloy components was the elimination of the source of failure, namely the transverse grain boundaries. This concept was recently developed2 to produce cast-to-size gas-turbine blades and vanes consisting entirely of columnar grains oriented parallel to the major stress axis of the component. Not only did the process impart increased rupture life and ductility to the components, but it also increased their resistance to thermal shock. During this development, the effect of unidirectional solidification on the properties of several alloys was investigated. The resulting data allows certain conclusions to be drawn regarding the factors affecting the creep and stress-rupture properties of the cast nickel-base superalloy and also its resistance to thermal shock. Detailed information was obtained on the alloys Mar-MZOO, B-1900, In 100, and TRW 1900. The composition of the alloys studied are shown in Table I. MATERIAL PREPARATION AND TESTING The conventionally cast alloys are cast as +-in.-diam bars in innoculated shell molds under conditions designed to maintain control of grain size. Unidirec-tionally solidified casting were produced in the form of 3-in.-diam ingots. Specimens from the latter were machined such that the axes of the columnar grains were parallel with the axis of the test bar, except in certain cases where the transverse properties of the material were being evaluated. The specimens were tested in an axial loading creep machine.' Temperatures were measured with thermocouples, attached just outside each end of the gage length, to assure uniform temperature along the entire specimen. Chromel/alumel thermocouples were used up to 1800"F and Pt/Pt-10 pct Rh thermocouples above 1800"F. The specimen temperature was recorded and maintained within i2"F throughout the test. Creep extensions were measured automatically with extenso-meters attached to ridges on the specimen and recorded continuously using linear variable differential transformers and multipoint recording equipment. MICROSTRUCTURE The microstructures of transverse sections of the four alloys studied are shown in Figs. 1 and 2. Fig. 1 shows optical micrographs of the alloys, both in the conventionally cast and unidirectionally solidified conditions. Each alloy displays a cored dendritic structure, a distribution of MC carbide, and the presence of the y — y' eutectic constituent.~ In the case of IN 100 and B-1900, Fig. 1 indicates that in these specimens the eutectic is degenerate. That is, it consists only of y' pools indicating that the y constituent has been solutioned during the cooling period after solidification. The major effect of unidirectional solidification on the microstructures of the alloys is a tendency to promote a more dendritic form of MC carbide and an increase in dendrite arm spacing, both effects being a result of the slower solidification rate in the unidirectional solidification technique. V, lec tron micrographs of transverse sections of the four alloys in the two cast conditions are shown in

Jan 1, 1968

By Bernard York, John J. Reed

W. 0. Philbrook (Carnegie Institute of Technology, Phila.)—Mr. DeVaney's paper is a valuable addition to the growing technology of the magnetic roasting of lean iron ores. His furnace is ingeniously designed to permit close control of the process and to achieve high thermal efficiency by counter-current heat exchange and the withdrawal of both solid and gaseous products at relatively low temperatures. The principle of using a lean reducing gas to avoid over-reduction of the ore even at high operating temperatures (for rapid reaction rate) is thoroughly sound. The gas analyses and flow rates reported, however, are internally incon- sistent and render suspect any details of a heat balance based upon them. While it is entirely proper to consider the entrant gas as a reagent and to account only for the heat evolved by consuming a portion of the gas, many operators are accustomed to a heat balance using the total calorific value of the reagent supplied; and comparison of heat balances made with different bases of calculation can be quite misleading. Since Mr. DeVaney's paper is likely to be cited frequently in future discussions of magnetic roasting processes, it seems worth while to point out the internal discrepancies and to give alternate values of heat requirements for different bases of calculation.

Jan 1, 1954

By Fred D. DeVaney

W. O. Philbrook (Carnegie Institute of Technology, Phila.)—Mr. DeVaney's paper is a valuable addition to the growing technology of the magnetic roasting of lean iron ores. His furnace is ingeniously designed to permit close control of the process and to achieve high thermal efficiency by counter-current heat exchange and the withdrawal of both solid and gaseous products at relatively low temperatures. The principle of using a lean reducing gas to avoid over-reduction of the ore even at high operating temperatures (for rapid re-action rate) is thoroughly sound. The gas analyses and flow rates reported, however, are internally incon- sistent and render suspect any details of a heat balance based upon them. While it is entirely proper to consider the entrant gas as a reagent and to account only for the heat evolved by consuming a portion of the gas, many operators are accustomed to a heat balance using the total calorific value of the reagent supplied; and comparison of heat balances made with different bases of calculation can be quite misleading. Since Mr. DeVaney's paper is likely to be cited frequently in future discussions of magnetic roasting processes, it seems worth while to point out the internal discrepancies and to give alternate values of heat requirements for different bases of calculation.

Jan 1, 1954

By J. Weijdema, D. N. Dietz

In the conventional underground combustion process (dry combustion) much heat is left behind in the swept formation and goes to rva.rte. Econonmy can be improved by heat recuperation through water injection. This is most advantageous if done at the earliest opportunity before much heat is dissiputed to cap and base rock. Water injected simultaneously with the air will flash to superheated steam, which passes through the combustion front together with the nitrogen from the air. A condensation front traveling up to three times as fast as the combustion front drives out the oil. In this type of wet combustion, the water evaporates before it reaches the combustion zone. The evaporation front travels more slowly than the combustion zone. If so much water is injected that the evaporation front overrun the combustion front, combustion in that spot will be quenched and some unburned fuel will be left behind. Air reacts with the oil farther down-stream where steam temperatures occur; at steam temperature, the air reacts rapidly with the oil. Velocity of the combustion front is increased thereby and is governed essentially by the water-injection rate. In the extreme case of high water-injection rate, a short heat wave of constant length is driven through the formation by water injection. Once this wave has been established, no more heat need be generated than that required to make up the heat losses from the short heat wave; a relatively low rate of air injection will suffice. The feasibility of partially quenched combustion has been confirmed in tube experiments. A heat wave at steam temperature is observed. Chemical analyses of flue gas indicate preferential burning of hydrogen while a carbonaceous residue is left in the formation. Introduction A disadvantage of so-called dry in situ combustion is that air-compression costs are rather high. An air consumption of about 400 std cu m/cu m (400 scf/cu ft) of formation swept is an accepted figure. This high consumption is mostly wasted since much heat is left behind in the depleted oil sand. Methods were investigated for recuperating as much as possible of the heat left behind. This paper deals only with basic principles and is confined mainly to one-dimen- sional flow without lateral heat losses; experiments were conducted in relatively narrow, well insulated tubes. If some water is injected with the air, it will turn to superheated steam in an evaporation front, which should travel behind the combustion front. The steam having passed the combustion front causes a steam drive by a condensation front that can travel faster than the combustion front. The latter needs to travel only part of the distance covered by the oil-displacing condensation front, and thus consumes less air. The water-air ratio would seem limited to that at which cold water overruns the combustion. This limitation was deliberately exceeded considerably in theory and experiments. It was found that combustion is then indeed quenched, but only locally. Farther downstream, the oxygen finds residual oil at steam temperature, which is suficiently high to ensure rapid oxidation. Thus, the combustion front uses only part of the available fuel because it is chased through the formation faster than its normal velocity. No heat is left behind. This new process is called "partially quenched combustion". At the upper limit of the water-air ratio, a small heat slug is moved through the formation by the flow of water and steam. Only a small flow of air is needed since it has only to generate sufficient heat to make up for the lateral heat losses of the short heat slug. Theory Although many factors complicate underground combustion, the processes will be presented in their simplest form. For this reason, one-dimensional flow without lateral heat losses is assumed. Heat conduction in the direction of flow also is disregarded. Under these conditions, dry combustion causes very high temperatures. The heat-carrying capacity of the gas stream is small. Heat generated by oxidation of a residual oil saturation is retained in the sand. The available fuel determines the air requirement and the temperature obtained. Accepting the often-mentioned air consumption of 400 std cu m/cu m (400 scf/cu ft) formation, we calculate a temperature of the swept sand of 1,200C (2,192F) (Fig, I). If water is injected at a modest rate with the air, it will flash to superheated steam upon contact with the heated sand. One cu m (35.31 cu ft) of hot formation will evaporate about 0.5 cu m (17.66 cu ft) of water, and thereafter will accommodate (at an estimated 0.80 saturation and an assumed 0.40 porosity) another 0.3 cu m (10.59 cu ft) of water in cold condition. As long as less than 0.5 + 0.3 = 0.8 cu m (28.25 cu ft) of water is injected for every 400 std cu m (14,125 scf) of air (water-

Jan 1, 1969

By H. W. Imholz

Active interest in the North Central Texas area centered in the development of the Palo Pinto limestone-producing zone, near the town of Avoca, in the northeast part of Jones County. This producing horizon was discovered in 1937, in the Iron Mountain Oil Company's well No. 1 Olander, in sec. 196, B.B.B. & C. survey, at 3238 to 3250 ft. During the development of this pool, it was generally referred to as the Avoca pool. As a second pool has been discovered in the same producing zone, also near the town of Avoca, the writer has taken the liberty of changing the name of the original Avoca pool to Avoca-Olander pool. Forty producers had been drilled in the Avoca-Olander pool by the end of 1938; their initial ranged from 28 to 300 bbl. per hour. Stimulus was given to the interest in the development of the Palo Pinto limestone when the Ungren-Frazier No. 1 Griffin, in sec. 199, B.B.B. & C. survey, Jones County, found the limestone from 3225 to 3250 ft., with an initial production of 931 bbl. per day. (This new pool has been given the name of Avoca-Griffin pool, by the writer.) The best well to be completed, up to the present time, is the Bert Fields No. 1 Taylor in sec. 199, B.B.B. & C. survey, which had an initial production of 748 bbl. in 3 hours. The Owen-Snebold No. 1 McKeever in sec. 158, B.B.B. & C. survey, in northwest Shackelford County, added to the interest in the Palo Pinto limestone when it extended the Ivy pool with a well in the Palo Pinto limestone from 3145 to 3183 ft., and was estimated good for 6,000,000 cu. ft. of gas and 6000 bbl. of oil per day. During 1938, Stonewall County obtained its first commercial producer when the Stonewall Oil Co. in No. 1 Parriott discovered the Palo Pinto limestone saturated from 5169 to 5176 ft. and tested 371 bbl. per day. Two new producing horizons were discovered about 2 miles east of the old Noddle Creek pool, Jones County; the first, the Humble Oil & Refining Co. No. 1 Irvin, in sec. 48, block 18, T. & P. R. R. Co. survey, which had saturated limestone from 2550 to 2567 ft. and was good for 100 bbl. per day; the second, in the Humble No. 1 Horton, sec. 40, which

Jan 1, 1939

By H. W. Imholz

Active interest in the North Central Texas area centered in the development of the Palo Pinto limestone-producing zone, near the town of Avoca, in the northeast part of Jones County. This producing horizon was discovered in 1937, in the Iron Mountain Oil Company's well No. 1 Olander, in sec. 196, B.B.B. & C. survey, at 3238 to 3250 ft. During the development of this pool, it was generally referred to as the Avoca pool. As a second pool has been discovered in the same producing zone, also near the town of Avoca, the writer has taken the liberty of changing the name of the original Avoca pool to Avoca-Olander pool. Forty producers had been drilled in the Avoca-Olander pool by the end of 1938; their initial ranged from 28 to 300 bbl. per hour. Stimulus was given to the interest in the development of the Palo Pinto limestone when the Ungren-Frazier No. 1 Griffin, in sec. 199, B.B.B. & C. survey, Jones County, found the limestone from 3225 to 3250 ft., with an initial production of 931 bbl. per day. (This new pool has been given the name of Avoca-Griffin pool, by the writer.) The best well to be completed, up to the present time, is the Bert Fields No. 1 Taylor in sec. 199, B.B.B. & C. survey, which had an initial production of 748 bbl. in 3 hours. The Owen-Snebold No. 1 McKeever in sec. 158, B.B.B. & C. survey, in northwest Shackelford County, added to the interest in the Palo Pinto limestone when it extended the Ivy pool with a well in the Palo Pinto limestone from 3145 to 3183 ft., and was estimated good for 6,000,000 cu. ft. of gas and 6000 bbl. of oil per day. During 1938, Stonewall County obtained its first commercial producer when the Stonewall Oil Co. in No. 1 Parriott discovered the Palo Pinto limestone saturated from 5169 to 5176 ft. and tested 371 bbl. per day. Two new producing horizons were discovered about 2 miles east of the old Noddle Creek pool, Jones County; the first, the Humble Oil & Refining Co. No. 1 Irvin, in sec. 48, block 18, T. & P. R. R. Co. survey, which had saturated limestone from 2550 to 2567 ft. and was good for 100 bbl. per day; the second, in the Humble No. 1 Horton, sec. 40, which

Jan 1, 1939

By C. B. Scotty, E. F. Egan

INTRODUCTION The neutron-garnma log has been used for stratigraphic correlation by the oil industry for a number of years. In the past few years, the quantitative application of the log to provide information with respect to porosity has received considerable attention. The basic concept of quantitative interpretation has been pointed out in the literature.1 It shall be the purpose of this paper to develop by empirical means a method whereby the relationship of porosity to neu. tron-gamma deflection may be predicted for various bore hole diameters. This relationship is applicable to the present commercially available neutron-gamma log run in open hole. Data available at present are insufficient to establish similar correlations for cased holes. Through the development of such a correlation, the importance of the various factors which influence the log become evident. NEUTRON-GAMMA CURVE The logging tool conisists of a source of neutrons and a means of detecting and measuring gamma rays, the detector being shielded from the direct emission from the source. The gamma rays reaching the detector have three sources of origin: (1) the natural gamma radiation emitted by the formations, (211 induced gamma radiation resulting from neutron bombardment. (3) gamma rays emitted by the source and scattered by the formation. It has been found that a neutron derived porosity correlation is best for shale-free formations. Under this condition the natural gamma ray radiation is quite low, and therefore, will be neglected in this work. The induced gamma ray radiation resulting from neutron bombardment is predominantly a function of the hydrogen atom concentration of the substance penetrated. Due to the geometry of the presently used system, the neutron-gamma curve indicates low radioactivity opposite high hydrogen concentration and high radioactivity opposite low hydrogen concentration (Figs. 1 and 2). Having a curve which measures hydrogen atom concentration, it follows that if the matrix of the formation penetrated consists only of atoms other than hydrogen, and if the fluid filling the pores is either oil or water, the curve should be an indication of porosity (both oil and water have practically the same number of hydrogen atoms per unit volume'). The above criteria for a porosity (Correlation are fulfilled in clean sandztones and limestones in which the pore volume is completely filled with liquids (oil or water), but not in formations containing either free gas or shale or both. Free gas. even under pressure, contains considerably less hydrogen per unit volume than oil and water; therefore, a variation in response on the curve would be expected. Camp- bell and Winter,' indicate that this difference in hydrogen concentration is sufficient to distinguish between sands containing water or oil and those containing dry gas. Shale is a mineral that contains hydrogen in its molecular structure in addition to the hydrogen which is present in the water of hydration. Thus, in formations containing variable amounts of shale, the hydrogen concentration indicated by the curve is not a direct indication of porosity. Bush and Mardock' have indicated that a correction may be made by use of the gamma ray curve to provide a porosity correlation. Since the induced gamma rays are predominaiitly a function of hydrogen concentration, it would be anticipated that the fluid filled bore hole would materially influence the logs. It has been pointed out that the neutron-gamma curve response decreases with increase in hydrogen concentration, therefore, the response due to the induced gamma ray component decreases with increase in fluid filled hore hole diameter. The scattered gamma ray component of the log increases with increase in bore hole diameter. Although there is an

Jan 1, 1952

By J. M. Toguri, K. Grjotheim

It is known 1,2 that the equilibrium between titanium metal, TiCl2 , and TiCl3, in a solvent of molten metal chlorides, is influenced both by the total amount of dissolved titanium and by the type of solvent. Assuming that the trivalent titanium forms the complex ion Ti111 Cl4, the equilibrium reaction may be expressed by the following equation, (Me) TiIII cl4+ 1/2 Ti = 3/2 TiII cl2+ (Me) Cl The ideal ionic equilibrium constant for this reaction is, Where the N's are the molar ionic fractions in the equilibrium melt, and (Me) the different types of cations present in the equilibrium mixture. The following thermodynamic relation is derived between Kand the concentration of cations in the equilibrium melt, mix The N"S are the equivalent ionic fractions, and so forth are constants corresponding to the standard changes in free energy for reactions in melts where only the cation indicated is present, and f (y1) is a function of the activity coefficients in the equilibrium mixture. When this term vanishes, a simplified linear relationship between In Kideal and the concentration is obtained. The simplified relationship has been applied with satisfactory results to the experimental data of Mellgren and pie,' and Kreye and Kellogg.2 MANY existing methods for the production of light metals involve the reduction of their respective metal halides in the presence of salt melts composed of alkali or alkaline earth chlorides. In such a solution phase, the light-metal halide may undergo stepwise reduction from a higher, to a lower valence, and finally to a zero valent state. In this connection, the disproportionation equilibrium is of great interest. In the case where the higher valence is three and the lower valence is two, the disproportionation equilibrium may be written as follows, 3 Me11 = 2 Me111 + Me [I] If this equilibrium occurs in a salt melt containing a large excess of alkali chlorides, a typical ionic melt is obtained. It is then possible to formulate the cation equilibrium: 2 Me+h' + Me = 3 Me++ [II] Reaction [11] is analogous to a cation exchange reaction. It has been shown thermodynamically that the equilibrium constant for such a reaction in 2

Jan 1, 1960

By G. C. Hancock

The operating plant of The Broken Hill Associated Smelters Pty. Ltd. is situated at Port Pirie in South Australia and it treats to finality the whole output of lead concentrates from the mines of The Zinc Corporation Ltd., North Broken Hill Ltd., and aroken Hill South Ltd. at Broken Hill, New South Wales. Lead bearing ores from other sources are also purchased for treatment and lead scrap and residues are treated on a toll charge basis. The present output of the plant is approximately 200000 tonnes of refined lead per annum and there is a substantial production of by-products including refined silver, gold, cadmium, antimonial lead alloys, copper matte and sulphuric acid. Recently the Company commenced the production of zinc by slag fuming and electrolysis from a six million ton dump of lead blast furnace slag, which has been accumulating at Port Pirie for over fifty years. The slag fuming plant contains two furnaces of conventional design, but features a high degree of pre-heat for the blast air and this is obtained by the use of all-metal recuperators. The raw zinc oxide fume produced by the plant is roasted in a rotary kiln prior to treatment in the leaching and electrolysis sections, which follow conventional practice for nigh current density plants. Present output is approximately 36000 tonnes of electrolytic zinc per annum.

Jan 1, 1970

By N. S. Stoloff, R. C. Ku, R. G. Davies

The stress-strain behavior of Fe-Co and Fe- V alloys containing up to 25 pct solute have been studied in the temperature range 25° to - 196°C. The microyield stress is independent of temperature for all alloys studied, while the temperature dependence of the ordinary yield stress is large and comparable to that for unalloyed iron. An alloy-softening phenomenon is observed for many alloys relative to unalloyed iron, and appears to be a consequence of removal of inter-stitials from solution and their subsequent agglomeration. The ductile to brittle transition temperature is increased markedly by both cobalt and vanadium. Transmission electron microscopy observations reveal that cross slip and cell formation are restricted with increasing solute, which can account for many aspects of yielding and fracture behavior. IRON and other metals of bcc structure slip on many planes of the (111) zone at moderate and elevated temperatures, giving rise to wavy glide. At low temperatures, however, there is a tendency for slip to be restricted to planes of only one or two crystallographic types; in the case of Fe-Si alloys for example, (110) glide predominates, giving rise to planar slip bands."' Restriction of cross slip at low temperatures in iron has been linked by Brown and Ekvall3 to increased strain hardening in the preyield microstrain region, leading to an apparently large temperature dependence of the yield stress. Support for this view has been provided by Lawley and Gaigher4 from a transmission electron microscope study of molybdenum. They concluded that dislocations at lower temperatures, by virtue of their inability to change planes readily, are unable to interact and annihilate, leading to an increase in internal stress and work-hardening capacity. Restriction of cross slip at low temperatures has also been suggested to be an important factor in determining the ductile to brittle transition of single-phase solids, including metals of bcc structure.5 It is pertinent to note that most solute elements tend to raise the ductile to brittle transition temperature of poly crystalline ferrite,6,7 although in some cases, e.g., Fe-Cr7 and Fe-Al,8 the dilute alloys may actually yield at lower stresses than unalloyed iron. It appears, therefore, that solute elements may have an effect analogous to lowering the test temperature with regard to restricting cross glide. Such an effect has indeed been observed in the ionic alloy system KCl-KBr,9 in which bromine atoms, although causing little misfit and consequently little effect on the yield stress of KC1, have a pronounced effect in restricting wavy glide and inducing brittleness. The purpose of the present investigation was to determine the effects of selected solute atoms on the yield stress and fracture behavior of iron, and to elucidate in turn how the slip character was related to these properties. Since it is known that interstitial atoms exert a strong influence on the mechanical behavior of iron, the solute elements chosen for study were vanadium, which reacts strong with interstitials,10 and cobalt, which does not form highly stable interstitial compounds." EXPERIMENTAL PROCEDURE Four-pound ingots of each of the following alloys were vacuum-melted in zirconia crucibles: Fe-1, 5, 10, 25 at. pct Co, and Fe-1, 4, 10, 20 at. pct V. An ingot of unalloyed iron from the same original stock as that used for the alloy was remelted under similar conditions to eliminate variations in interstitial content arising from differing thermal histories. Chemical analyses of the iron, cobalt, and vanadium melt stock are listed in Table I. All ingots were rolled and swaged, commencing at 850°C, to 1/4-in.-diameter bar. The bars were then annealed at 850°C for 1 hr (except that the 10 and 20 pct V alloys were heated for 2 hr) to give a uniform equiaxed grain size of about 0.05 mm. Tensile samples of 0.125 in. diameter by 0.8 in. gage length were utilized for studies of the ductile to brittle transition. A second set of tensile samples were utilized for microstrain experiments in which strain sensitivity of 1 x 10"6 was achieved by a capacitance method.3 Cylindrical compression samples 0.250 in. diameter by 0.4 in. long also were prepared to study the influence of composition on the macroscopic yield stress, and for metallographic analyses of defor-

Jan 1, 1965

By Zay Jeffries

This paper will include a brief discussion of Prof. Howe's paper on The Supposed Reversal of Inheritance of Ferrite Grain Size from that of Austenite.l The general subject of grain refining in steel and iron will also be treated. The conclusions reached are stated in the following hypotheses which are discussed more in detail below. 1. The ferrite grain size in pure iron, the ferrite and pearlite grain size in hypoeutectoid steel, the pearlite grain size in eutectoid steel and the cementite and pearlite grain size of hypereutectoid steel are not inherited from the grain size of the mother austenite. 2. The only structural feature that is generally inherited from the austenite of hypo- and hypereutectoid steels on cooling through their transformation ranges is the position of the excess ferrite or cementite at the austenite grain boundaries, sometimes causing complete and sometimes incomplete networks which outline the old austenite grain boundaries. Rapid cooling through the transformation range will cause the non-inheritance of this structural (network) feature. 3. The austenite grain boundaries themselves are nearly always effaced in all steels and also in pure iron during the At transformations. 4. The grain-size refining of steel and iron is brought about by the combined effect of non-inheritance of the transformation products on either heating or cooling, i.e., the austenite transformation products do cst inherit their grain size from the austenite on cooling through the transformation range nor does austenite inherit its grain size from the products which form austenite on heating. 5. In general, in both iron and carbon steel the larger the austenite grain size, the larger will be the grain size of the transformation products on cooling. This, of course, assumes all other conditions constant except the austenite grain size. An exception is found to this general rule in very pure iron such as electrolytic iron. In this instance small austenite grains may form very large ferrite grains on cooling through Arg.

Jan 1, 1918

By H. Le Chatelier

SILICA brick are indispensable in the manufacture of steel because they alone are able to withstand the high temperature of regenerative furnaces. All attempts to replace silica brick by other refractory materials for this purpose have failed, but the reason for this failure has remained obscure; we shall give an explanation later in this paper. Before the war, silica brick employed in France came principally from abroad, for which reason, since the beginning of hostilities, certain French steel works have been seriously handicapped. Our attention was first directed to the question by M. Bred, Engineer of the Teil Works. With him, we began certain investigations, at first using our laboratory and the furnaces of neighboring steel works. The larger part of our experiments, however, have been made in the laboratory of the Faculty of Sciences at the Sorbonne. For the heating of our samples, we are deeply obliged to MM. Charpy, Yeatmann and Guérineau. In undertaking these studies, our first aim has been to render assistance to French industry, by indicating, as precisely as possible, the necessary conditions for the manufacture of high-grade brick; but at the same time we have intended to give an example of the manner in which scientific methods may be put to practical application in the solution of industrial problems. Although our work has been confined to samples of only a few grams, we are nevertheless convinced that our information can be directly utilized by brick-works of which the output is measured in thousands of tons

Jan 9, 1918

By Donald W. Scott, Nathaniel Arbiter, A. C. Richardson

This paper describes the application of amine flotation to a specific problem—that of increasing the grade of magnetite concentrates derived from an iron ore requiring extremely fine grinding for mineral liberation. Experiments conducted on an iron ore from Wisconsin had shown that concentrates containing 60 to 62 per cent iron and 12 to 14 per cent silica could be produced by magnetic separation. The residual silica occurred as quartz and hornblende, either entrained or locked with magnetite. Most advantageous utilization of the concentrate, however, necessitated that the silica content be reduced to about 5 per cent, equivalent to an iron content of 67.5 per cent. It had been demonstrated that tabling of the magnetic concentrate removed sufficient quartz and hornblende to yield an acceptable concentrate, but disadvantages inherent in tabling dictated that flotation be investigated as a substitute. The goals set for the flotation investigation were: (I) the production of concentrates of about 68 per cent iron content from the magnetic concentrate; (2) an iron recovery of about 85 per cent of that in the feed to flotation; and (3) minimum reagent cost. Both batch and continuous flotation tests were employed; the former, to establish the procedure and the latter to verify it. Although the data were obtained on a specific ore, and with a commercial application in view, it is believed that they have a bearing on other problems where amine flotation is being used or is anticipated. Samples Two samples, designated "(minus 100-mesh magnetic concentrate" and "minus 150-mesh magnetic concentrate," were used for the batch experimental work. They differed only in the degree to which the crude ore was ground prior to magnetic separation. They were stored moist in steel drums in quantities sufficient for all the experimental work reported. This procedure had the advantage of allowing all tests to be made on common samples, but had the disadvantage that the individual flotation samples, because of the difference in storage time, were subject to various stages of surface alteration. Previous work had indicated that common samples were desirable for the batch studies, and it was decided that if these data appeared sufficiently promising the effect of surface alteration could be checked best by continuous tests. The size distributions and the assays of the samples are given in Table I. The minus 150-mesh magnetic concentrate, on which most of the flotation tests were made, assayed 60.9 per cent iron, 13.3 per cent silica, and 0.016 per cent phosphorus. The minus 325-mesh portion represented 78.I per cent of the sample by weight, and assayed 67.9 per cent iron. Thus, the insoluble, mainly silica, was concentrated

Jan 1, 1947