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By Albert J. Phillip

Jan 1, 1947

By Albert J. Phillip

Jan 1, 1947

By B. M. Bird

DURING the past four years the experimental work in coal washing carried on by the U. S. Bureau of Mines and the University of Washington has been devoted mainly to the development of special methods for the tabling of fine sizes of coals that are difficult to wash. One important outgrowth of this investigation has been the application of hindered-settling classification to coal tabling. Although used for many years in ore dressing, the term "classification" as used here may be new to many readers. It may be defined as the separation obtained when a bed of particles is held in a uniform state of suspension in an upward current of water, either continuous or pulsating, just sufficiently strong to keep the bed in a mobile condition. A common example of this type of separation is a jig in which there is no suction stroke. When the hindered-settling classifier is used with the coal-washing table, the fine-size raw coal, instead of being fed direct to tables, as is the prevailing practice, is first fed to the classifier and grouped, according to the rate of settling against the upward current of water, into perhaps six separate products. After dewatering, each of these except the sixth, a refuse product, is elevated to a seperate feed bin and washed on a separate table. This paper gives a brief discussion of the basis for the use of hindered-settling classification of a table feed; a description of the experimental work; a comparison of the results obtained with and without classification; and a discussion of the application of the classifier in commercial coal washing.

Jan 1, 1928

By Alfred H. Bell, George V. Cohee

In 1939 Illinois produced 94,302,000 bbl. of oil—almost three times the amount of oil produced at the peak in 1908, when development in the southeastern Illinois field was at its height (Fig. I). It represents nearly a fourfold increase over the 24,075,000 bbl. produced in 1938 (Table 6). This rapid increase in oil production in Illinois is largely due to development in the Salem and Louden fields (Table I). During 1939 daily production for the state increased from 135,000 to 332,572 bbl. A notable increase in production for 1940 is expected as a result of the drilling of the Devonian limestone in the Salem and Centralia fields,

Jan 1, 1940

By Alfred H. Bell, George V. Cohee

In 1939 Illinois produced 94,302,000 bbl. of oil—almost three times the amount of oil produced at the peak in 1908, when development in the southeastern Illinois field was at its height (Fig. I). It represents nearly a fourfold increase over the 24,075,000 bbl. produced in 1938 (Table 6). This rapid increase in oil production in Illinois is largely due to development in the Salem and Louden fields (Table I). During 1939 daily production for the state increased from 135,000 to 332,572 bbl. A notable increase in production for 1940 is expected as a result of the drilling of the Devonian limestone in the Salem and Centralia fields,

Jan 1, 1940

By G. L. Oldright

THE development of the reverberatory furnace for smelting copper ores up to 1912 was described by E. P. Mathewson1 with details concerning the great changes in dimensions of the furnace. Hayward2 tabulated similar data, giving developments up to about 1924, in his revision of Hofman's Metallurgy of Copper. DEVELOPMENT OF PRESENT SMELTING PRACTICE Dimensions of Furnace Very great changes were made in the dimensions of the smelting hearths of the furnaces in the period from about 1800 to 1906, the length increasing from about 11 to 116 ft., and the width from 8 to 19 ft. During this time the tonnage smelted increased from about 9 to 250 tons per 24 hr., and the tons of charge smelted per ton of coal increased from 0.77 to 4.3. Dr. Mathewson3 noted no great difference in the "fuel ratio" (i. e., the amount of charge smelted per ton of coal) as the furnace at Anaconda was increased in length by stages from 85 to 116 ft. (The percentage of copper in the slag, however, was lowered from 0.42 to 0.36 per cent. The other components of the slag were not given.) Lump coal fired on grates was the fuel used during this period. The practice in operating the furnaces over such a length of time naturally varied considerably, and there were differences in composition and nature of the charge, yet it may be considered that the improvements made were due largely to increases in the size of the furnace used. Doubt-less some credit should be given to improvements in operating technique, like changes in the methods of firing the lump coal. However, the greater part of the advance was probably due to factors influencing the

Jan 1, 1928

By Rex B. McLellan

Studies of the eyuilibrzum between ferrite and austenite with gas mixtures (CO + CO2 and H2 + CHe) have been used as a means of deducing the energy and vibrational entropy of carbon atoms in dilute interstitial Fe-C solutions. A simple model for dilute interstitial solutions is given which enables a solubility equation for the equilibrium between the gas mixtures and the solid to be deduced. This solubility equation is used to estimate the partial In this work measurements of the equilibrium between dilute solid solutions of carbon in iron and gaseous mixtures of CO2 + CO and CH4 + Hp have been analyzed using theoretical solubility equations deduced from a knowledge of the thermodynamic parameters of the gas mixtures and an appropriate model for the solid solution. The solubility equations are deduced by equating the chemical potential of carbon atoms in the gas thermodynamic functions of dilute Fe-C solutions from the measured equilibrium between the solid and the gas mixtures. It is shown that the vibra-tional entropy of a carbon atom in a and y iron is smaller than the corresponding entropy 01. a nitrogen atom in solid solution inferrite or austenite and that there is little difference between the vibrational entropies of both nitrogen and carbon atoms in ferrite and austenite. and solid phases. The chemical potential of carbon in the gas is found from a simple statistical mechanical analysis of the gas mixtures utilizing spec-troscopic data while that for carbon in the interstitial solution is found from a model in which the carbon atoms act as bound oscillators distributed in a random fashion in the solution. The solid solution is dilute enough to enable solute-solute interactions to be ignored. Thus the configurational entropy of the solution is ideal but the mixing entropy contains additional excess terms due mainly to the vibrational changes occurring on solution formation. The partial excess entropies (and the partial energies) do

Jan 1, 1965

By Edward H. Robie

THE registration badges gave out, there were not enough programs, the Pioneer Hotel's rooms were insufficient, and some hundred applicants for banquet tickets had to be turned down at the Institute's Regional Meeting in Tucson, Nov. 1-5. Minor inconveniences these, however, occasioned by the fact that, optimistic as they are in Arizona, about half again as many partook of the week's activities as were expected. For this, the local program committee can be blamed-both the technical and social features were too attractive in quantity and quality. Seriously speaking, though, the Institute has probably never had a more successful Regional Meeting than this one. It being the first that has been held in Arizona in 22 years, no effort was spared to make it the distinctive gathering that it was.

Jan 1, 1938

By J. S. Osoba, J. W. Graham, P. H. Monaghan

Of the many factors which affect the productivity of hydraudically fractured wells, the wettability of the propping sand has received little attention in the pas/. This paper shows that the wettability of the propping sand is an important factor which shorcltl not he overlooked. An analysis of relative permeability data shows that fractures packed with water-wet sand should be more permeable to oil than are fracturer packed with oil-wet sand. Laboratory results verify this conclusion. Cnlculations show that higher permeability to oil in the fracture should provide higher well productivity. A method is presented which ensures that the propping sand in an induced fracture is water-we1 even though oil is used as the fracturing fluid. The rnethod has been used in more than 150 field jobs: the field resrrlts are discussed briefly. The fluidized nature of water-wet sand in oil has giver1 unexpected benefits. This characteristic of water-wet sand and how it has been used advantageously in field operations are discussed. INTRODUCTION Hydraulic fracturing of subsurface strata to increase the productivity of oil and gas wells has been practiced for about 10 years. Today, fracturing is used more often than any other method of well stimulation. Basically, the process consists of breaking down (fracturing) a subsurface formation with pressure applied by means of a carrier fluid, usually oil or water, and propping the induced fractures apart by means of an agent, usually sand. suspended in the carrier fluid. Currently about 68 per cent of all fracturing is done with a simple mixture of refined oil or lease crude oil and sand'. The research of other investigators has suggested that dry sand is rendered oil-wet when it is contracted with certain types of crude or refined oils.' Hence, it may be expected that some fracturing operations employing an oil as the carrier for sand leave fractures packed with oil-wet sand. Conversely, those operations which employ water as the carrier for the sand probably leave the fractures packed with water-wet sand. Since the permeability of a sand-packed fracture to a mixture of oil and water is dependent upon the wettability of the fracturing (frac) sand, research was undertaken to determine to what extent the wettability condition (water-wet or oil-wet) controls fracture permeability which, in turn, affects well productivity. Additional research was directed toward the development of a method for obtaining the desired fracture wettability. In this report both theoretical and experimental evidence is presented to show the desirability of employing water-wet sand in fracturing operations. A method to obtain water-wet sand is discussed, and field results are reviewed briefly. DEPENDENCE OF WELL PRODUCTIVITY ON FRACTURE WETTABILITY To determine the dependence of well productivity on the wettability of the frac sand, it is necessary to know, first, the effect of fracture wettability on fracture permeability and, second, the effect of fracture permeability on well productivity. The relationship of these variables is considered separately in the order indicated. Effect of Wettability on Permeability Fig. 1 shows relative permeability relations for 20-30 mesh Ottawa sand. Inspection of these curves reveals that the relative permeability to oil when a small amount of water accompanies the flow is considerably higher when water rather than oil is the wetting phase. For

By Evan Just

THE high standards of living and improved national security that industrialization can bring are so evident that no country can be named that does not cherish the hope of industrializing. With such a universal aim, why do many countries unable to develop their own industries accomplish so little toward attracting the foreign private investor, who alone can provide them with the necessary capital and skill? Obviously, because they fail to under- stand what constitutes a favorable climate for investment, because they have false notions about being exploited or dominated by the foreign investor, or because they are so nationalistic they refuse to permit outside assistance. The purpose of this paper is to aid the citizens and policy makers of developing countries in achieving their aims, by defining the conditions which en- courage investment and portraying the results of a policy of encouragement. The following is quoted from Eugene R. Black, president of the World Bank:

Jan 6, 1957

By G. C. Bernard, L. W. Bernard, L. W. Holm, W. L. Jacobs

The effect of loam on the permeability of porous media to water was studied as a {unction of foaming agent concentration, specific permeability, pressure gradient, length of a porous medium and its oil saturation. At a given fluid saturation in a porous medium, the permeability to water was found to be the same whether loam was present or not. Foam decreases the permeability to water by developing a higher trapped gas saturation than that obtained by water flooding without loam present, increasing the concentration of foaming agent increased the trapped gas saturation and thereby decreased the permeability to water. The presence of oil reduced the capability of most foaming agents to decrease the permeability of a porous medium to water. A few surfactants were found to be effective loaming agents even in the presence of oil. These results are similar to those reported in a previous paper on the effect of loam on the permeability of porous media to gas. The effect of loam was found to persist in long porous media at moderately high reservoir temperatures and during the passage of many pore volumes of surfactant-free water. INTRODUCTION This paper describes part of a study on a novel approach in the use of surfactants for oil recovery; the use of foam rather than water to displace oil. Previously it was found that foam can displace oil which normally is not displaced by water.4 The foam is formed by successively injecting a suitable surfactant solution and gas into a porous medium. Foam appears to have at least two uses in the field: (1) it shows promise as a superior oil recovery agent, and (2) it shows promise as a selective permeability reducing agent. Foam may be very useful in water floods, or in other oil recovery processes, where highly permeable streaks or unfavorable mobility ratios are a problem. A previous paper reported the effect of foam on the permeability of porous media to gas.1 In the present study the effect of foam on the permeability of porous media to water is reported. The specific objectives of the study were to determine: (1) the effect of foam on the permeability to water in porous media of various specific permeabilities, (2) the effect of foam on the permeability to water in the presence of oil, (3) the effect of foam and crude oil on the trapped gas saturation, (4) the effect of foam on permeability to water at trapped gas saturation, (5) the effect of pressure gradient on the permeability to water under foaming conditions, (6) the persistence of foam during the passage of surfactant-free water through the porous medium, and (7) the effect of various foaming agents, length of the porous medium and temperature on the permeability reduction caused by foam. EXPERIMENTAL PROCEDURES EQUIPMENT AND MATERIALS The experimental apparatus consisted of consolidated and unco n soli dated porous media, wet test meters and constant delivery pumps. The porous media consisted of consolidated sandstone cores (6 to 36 in. long), and unconsolidated sand packs (3 to 30 ft long). The consolidated cores had permeabilities of 32 and 1,000 md and porosities of about 20 per cent. The sand packs had permeabilities of 3,500 to 211,000 md and porosities of about 40 per cent. (Throughout this report a term such as 100 md sand" is used. This term means that the porous medium had a dry, nitrogen permeability of 100 md.) Fluids used in the experiments were distilled water, 1 per cent NaCl solution, aqueous solutions of foaming agents, nitrogen gas, air and crude oil.

Jan 1, 1966

By E. Hornbogen

Discontinuous precipitation in a iron can occur by at least two different mechanisms. These mechanisms are compared, using observations made on an Fe-22 at. pct Zn alloy and an Fe-19.5 at. pct Mo alloy. In the Fe-Zn alloy, precipitation began on grain boundaries. These boundaries moved into the supersaturated solid solution, providing nucleation sites and an easy path for diffusion. The precipitated phase pew as lamellae, perpendicular to the PRECIPITATION reactions are called discontinuous if the nucleation of particles does not occur on individual sites in the supersaturated matrix.' In discontinuous precipitation, nucleation and growth occur on a reaction front that moves into the supersaturated solution and leaves a two-phase aggregate behind. The term cellular precipitation2 has also been used, but the term autocatalytic precipi- moving reaction front. The orientation of the depleted iron differed from that of the supersaturated iron. In the Fe-Mo alloy the growing precipitate particles apparently created dislocations in the growth front which served as nucleation sites. The precipitate grew on (110) planes of the iron, and growth occurred through volume diffision. The depleted iron retained the orientation of the supersaturated solid solution. tation seems to describe the nature of such reactions best. The basic effect of such a precipitation mechanism in a solid is that it is able to move or create sites that can catalyze nucleation. Such sites can be grain boundaries and dislocations. A mechanism of autocatalytic precipitation must, therefore, include some rational process by which a grain boundary may move into the supersaturated matrix or by which dislocations may be generated in front of the reaction. Discontinuous precipitation is always in competition with individual nucleation and growth of par-

Jan 1, 1963

By R. N. Kust, J. C. Agarwal, H. E. Barner, N. Beecher, D. S. Davies

Kennecott Copper Corp. has developed a new hydro-metallurgical process for extracting nickel, copper, cobalt and molybdenum from manganese nodules. This process (KCC Cuprion Process) utilizes a reduction leach operating at atmospheric pressure in the temperature range of 45 OC to 50°C and has been successfully demonstrated in a continuous pilot plant processing 350 kg/d of nodule ore. The chemistry, basic flowsheet and operating characteristics are presented and discussed.

Jan 1, 1980

Executive HOWARD N. EAVENSON, Chairman FREDERICK M. BECKET EDGAR RICKARD ERLE V. DAVELER WILLIAM WRAITH Finance HENRY KRUMB, Chairman PAUL I). MERICA J. V. W. REYNDERS H. G. MOULTON, Consultant Admissions JOHN M. LOVEJOY, Chairman GEORGE D. BARRON DONALD M. LIDDELL ELI T. CONNER WILLIAM W. LYNCH Alternates WM. H. BASSETT, JR. L. B. LINDEMUTH W. A. SINSHEIMER

Jan 1, 1934

By D. A. Thomas, M. F. Comerford

Poly crystalline wires of Fe-3.2 wt pct Si were cold-drawn to 31, 66, and 87 pct reductions of area. Mechanical properties and tnicrostructures were studied after recovery and re crystallization. An initial increase in strength during recovery was ascribed to strain aging, and subsequent softening was largely due to polygonization rather than re-crystallization. No unique actioation energies could be determined for the recovery process. Rather, activation energies ranged from 60,600 cal per mole at 10 pct recovery to 83,200 cal per mole when recovery was 50 pct complete. Sites for the nucleation of recrystallization were found to depend on time and temperature. In the early stages of re-crystallization, nucleation occurred in deformation hands. Later, or at high temperatures, recrystal-lized grains were nucleated primarily al grain boundaries. Polygonized structures did not seem to be preferred sites for nucleation. MUCH of the research on deformation, recovery, and recrystallization processes in bcc materials has been performed on single crystals or lightly worked polycrystals. Little study has been devoted to the relation of mechanical properties to micro-structure in polycrystals after severe deformation and subsequent annealing. This paper presents the results of a study of the tensile properties and microstructures of Fe-Si wires drawn varying amounts and annealed at a series of temperatures. EXPERIMENTAL PROCEDURE The experiments were carried out on an alloy of the following composition: 3.2 wt pct Si, 0.08 Mn, 0.016 C, 0.005 0, 0.0002 N, 0.0001 H, 0.008 P, 0.034 S. The material was received as l-in.-sq bars cut longitudinally from a hot-rolled slab provided by the Armco Steel Corp. The bars were forged to 3/8-in. rounds, centerless-ground to 0.250 in., and swaged to '0.108 in. All subsequent reductions were performed by room-temperature wire drawing at the rate of 2 in. per min. Each preliminary draft gave approximately 30 pct reduction of area and was followed by a l-hr anneal at 1010°C in dry hydrogen. Three lots of wire were made with ultimate cold reductions of 31, 66, and 87 pct reduc-

Jan 1, 1965

By Norman D. Fitzgerald

IN 1943 the petroleum industry completed a series of practical adjustments to the acute problems which dominated the scene a year earlier. The crisis in petroleum transportation from the Gulf Coast to the East Coast was met by the completion of overland pipe lines supplementing emergency haulage by tank car so pressure on consumers along the Atlantic Seaboard was appreciably relieved. Later in the year when the western Atlantic was largely cleared of submarines, the sharp reduction in the hazards of marine transportation permitted the resumption of coastwise traffic and imports from South America. Nationwide restrictions in the use of gasoline and fuel oils became necessary as military demands for all petroleum products mounted to high levels.

Jan 1, 1944

By R. L. Vaughn, H. R. Cooper

Effective procedures for automating X-ray assaying by use of a computer are described. These methods have advanced the reliability and accuracy of X-ray data, resulting in improved assay measurements for operations and process control. Assaying by X-ray fluorescence has been increasingly used in the mining industry, both for analyzing solid H.R. COOPER and R.L. VAUGHN, Members AIME, are Systems Manager-Process Control and Senior Systems Analyst, respectively, Scientific & Engineering Computer Center, Ken-necott Copper Corp., Salt Lake City, Utah. TP 68B236. Manuscript, Sept. 16, 1968. Discussion of this paper, submitted in duplicate prior to Dec. 15, 1969, will appear in SME Transactions, March 1970, and AIME Transactions, 1970, Vol. 247. samples for smelter, mill, and mine quality control and for continuous stream analysis of mill pulps. The important advantages of X-ray methods in laboratory assaying are reduced analysis cost, and for on-stream analysis, immediate assay information on concentrator streams. Of the numerous reports concerning X-ray analysis in mining operations, one is referenced which can be noted particularly in conjunction with this report.' Continuous X-ray analyzers have been installed at Kennecott and other mining companies for operations guidance and trend information for a number of years. However, complete operational acceptance of X-ray data has been slow, due* to the difficulty in maintaining

Jan 1, 1970

By Roman Šejnoha, Karel Mazanec

A pronounced tendency for delayed fracture zoas observed in the martensite structure of low-alloy steels in the as-quenched condition. Cracks of predominantly intercrystalline nature nucleated and propagated at stresses substantially lower than the short-titne tensile strength of- the steels, and were observed even in hydrogen-free speciunens. The occurrence of delayed fractures in the as-quenched condition is interpreted as a supevposition of the effect of free dislocations generated during the martensite transforlnation, and of a weakening of the prior austenite grain boundaries caused by dynamic shocks exerted on the boundaries by growing martensite plates. AN important metallurgical problem, connected with the production and use of high-strength steels, is delayed fracture in martensitic structures. Such fractures occur in quenched steels as a result of prolonged loading with external stresses far lower than the short-time tensile strength of the steel. The same effect can be produced by sufficiently high internal stresses: it is well-known that quenched structures will in some cases crack intergranularly at room temperature if not tempered quickly enough even in the absence of any externally applied stress. In Troiano's papers1,2 on delayed fractures in high-strength steels, the fundamental role of hydrogen migrating under the influence of multiaxial stress towards the nuclei of cracks was found. Fig. 1 shows the typical relationship between stress and the time to fracture found by Troiano in hydrogen-charged high-strength steels. On the other hand, Shurakov 3,4 explains the realization of delayed fractures in martensite as due to a "quasi-viscous" behavior of the austenite grain boundaries immediately after the martensitic transformation. 1) MATERIALS AND EXPERIMENTAL METHODS Two low-alloy steels of commercial purity were used for the experiments reported in this paper. Their chemical composition is shown in Table I. The heats were melted in a laboratory furnace, cast to ingots, forged to bars of 3/4 in. diameter, and annealed. Machined test pieces were heat-treated as follows: Ni-Cr-Mo steel held at 900°C for 30 min and quenched in oil; Mn-Si-Cr steel held at 900°C for 30 min and quenched in water. For the delayed-fracture tests, notched cylindrical test pieces, Fig. 2, stressed in torsion, and unnotched cylindrical tensile-test pieces, 1/4 in. diameter, were used. The specimens were normally loaded with a constant static load 45 min after quenching for the torsional tests and 10 min

Jan 1, 1965

By J. David Lowell

For the first time in several years, Chile is again opening its doors to foreign investment. In its new investment code, the Chilean government has announced its willingness to become a partner in joint Chilean-foreign projects for a number of government-controlled porphyry copper deposits at the developed, semi-developed, or prospect stage; and, that it will allow privately owned deposits or deposits discovered by new exploration to be developed with up to 100% foreign ownership. Three deposits of particular interest are: El Abra, with at least 300 million mt of +100% Cu; Los Pelambres, with at least 428 million mt of 0.78% Cu and 0.03% Mo; and Andacollo, with 350 million mt of 0.70% Cu and 0.015% Mo. (El Abra is almost entirely government- controlled; but both Los Pelambres and Andacollo are mostly under private ownership.)

Jan 11, 1974

Jan 1, 1905