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By Allen Garrison

A PREVIOUS paper1 reviewed some of the properties of clays and shales and presented some data on the nature of the gelling phenomenon. It included a brief discussion of origin of clays and shales, their com-position, structure, retention of water, ionization, base exchange, and the nature of the gelling of water suspensions, Other publications of the Institute2-8 have discussed the properties of clays and their relations to drilling-fluid behavior and control. It is the purpose of this article to present some new data obtained and arranged in a different manner and making possible a better understanding of the chemical reactions involved in the control of drilling-fluid characteristics during the normal drilling operations. EXPERIMENTAL PROCEDURE The difficulties involved in the measurements of the flow character-istics of plastic fluids are too familiar to recite, The possible applications of some of the well-known instruments to this problem have been ade-quately discussed by Hobson9 and he has given an excellent bibliography. Although there are many viscosimeters of varied design, none of them appear to fulfill the most obvious demands of accuracy in the measure-ment of clay or shale suspensions, Since the fluid characteristics are dependent on the rate of flow of the fluid, and the viscosity usually falls off very rapidly as the rate is increased, it is clear that the first require-ment is that the instrument shall be capable of a wide variety of speeds. The viscosity of the fluid at any fixed and constant rate of flow is also a function of time, so that the second demand is that the instrument shall be capable of a constant and continuous motion for a prolonged period of time.

Jan 1, 1939

By D. J. Rose, W. M. Armstrong, A. C. D. Chaklader

The wetiability of single crystals of MgO by specimens of vacuum-cast iron was studied using the sessile drop technique in vacuo at 1550ºC. Formation of FeO at the liquid-vapor interface caused the contact angle (6) to decrease from 117 to 65 deg during the first minute. After cooling, all specimens possessed a peculiar annular interfacial deposit of Fe,O,. Within the annulus the interface showed no sign of chemical attack. Chemical reaction occurred where the iron was alloyed with Ti, V, Cr, Nb(Cb), Ta, cmd Zr. Vnriation of 6 with alloy concentration was studied. Although vanadium md chromium improved the wettability of MgO by iron, the effect of Zr, Ti, Nb, and Ta was indeterminable because the 8 derived from sessile drop considerations was that of the metal against a restrictive peripheral volume of liquid oxide wetting the substrate. INTEREST in the nature of metal-ceramic interactions has been stimulated by progressive development of metal-ceramic combinations. One of the more valuable methods used for bond investigation is the sessile drop technique. Recent attempts to improve wettability through solute additions to the drop have revealed that the solute may a) react with the oxide creating new compounds at the solid-liquid interface, b) adsorb at the interface in a monolayer formation, or c) distribute throughout the drop uniformly causing no wettability variation. This work, part m in a series1,2 of investigations of interface reactions between metals and ceramics, embraces a study of the Fe-MgO system. MgO possesses a large negative free energy of formation (-173 kcal per g mole 0, at 1550ºC) compared to FeO at this temperature (-73 kcal per g mole 02). Hence the electronegativity difference between the drop and substrate allows selection from an extensive group of metal solutes with intermediate electronegativity differences that would, in the absence of chemical reactions, be expected to adsorb pre- ferentially at the solid-liquid interface. However, the high oxygen pressure of MgO in vacuo creates an oxidation environment which influences the solute behavior. Recent studies of the Fe-MgO systemJ74 have been restricted by chemical reactions that obscured observations. In view of the current interest in liquid-phase sintering of metal-ceramic combinations under partial oxidizing conditions,5 a more comprehensive study of the Fe-MgO system seemed beneficial. EXPERIMENTAL PROCEDURE 1) Specimen Preparation. Optical-grade MgO single crystals and Ferrovac vacuum-cast iron were used in all experiments. A spectrographic analysis of the iron indicated 0.008 C, 0.05 V, 0.005 Mo, 0.01 Ti, 0.002 S, 0.01 Cr, 0.001 Mg, 0.01 Si, 0.003 A1 (wt pct). The MgO crystals were cleaved along (100) planes into plates approximately 20 by 20 by 1 mm. Following annealing in vactto at 1100°C for 3 hr, surface irregularities were removed by a chemical etch in phosphoric acid at 100°C. The iron rod was machined into small cylinders approximately 0.250 in. in diam and length and these were carefully cleaned in organic and acidic solutions to remove surface impurities. All specimens were weighed to the nearest 0.1 mg. 2) Apparatus. The apparatus described in detail by previous authors1,2 was modified for this work. A Polaroid Land Camera was incorporated into the optical system so that drop measurements at ten-second intervals after melting were possible with ultra-high-speed self-develop ing film. 3) Procedure. The iron cylinders were placed upright on the MgO plates and positioned in the molybdenum susceptor. After furnace assembly the system was pumped down to a vacuum of 1 µ and flushed with H2 at 800°C. The system was again evacuated to 5 x 10-5 mm of mercury and the temperature raised to 1550°C within 2 min. The molten drops were photographed at appropriate time intervals. TWO min after melting the iron vapor pressure caused gas discharge, or corona, within the tube. The specimens were then slowly cooled to room temperature, sectioned and examined metallographi-cally. X-ray identification of interfacial reaction products was attempted by the powder diffraction technique. Alloying elements (Ti, V, Cr, Zr, Ta, Nb) were added to the iron in various concentrations up

Jan 1, 1963

By R. T. Hukki

This paper presents a series of equations for mechanical ball wear, relating parameters of ball size, mill speed, and mill diameter. The fundamental equation, Eq. 12, presented here is introduced to correlate these basic parameters and thus define and clarify the concept of ball wear. This equation is offered as a general rule, which may be modified to apply to individual problems of grinding. BALL wear as observed in grinding installations is the combined result of mechanical wear and corrosion. Corrosion should be a linear function of the ball surface available. Ball corrosion, however, has been studied so little that its effect, although of great importance, cannot be included in the analyses given here. In a separate paper' it is shown that 1 n = 0.7663 np----=— rpm [1] vD P = c, np D kw [2] T=c²(np)n De tph [3] In these equations n — actual mill speed, rpm np = calculated percentage critical speed D = ID of mill in feet P = power required to operate a mill, kw T = capacity of a mill, tph C¹ and c² - appropriate constants in = exponent of numerical value of 1 5 m 1.5 Exponent m is the slope of a straight line on logarithmic paper relating mill speed (on the abscissa) and mill capacity (on the ordinate). It is generally accepted, although not sharply defined, that ball wear in mills running at low (cascading) speeds is a function of the ball surface available. Accordingly, the wear of a single ball may be considered to be a homogeneous, linear function of its surface and of the distance traveled. Thus dw = f¹(d2) . f2(ds) [4] where dw is the wear of a single ball in time dt, d the diameter of the average ball in ball charge, and ds the distance traveled by the ball in time dt. Indicating that ds - a D n dt, the wear of the average ball in time dt becomes dw = f¹(d2) . f2(Dn dt) 1 --- f¹ (d1) f² (D c3 np-----— dt) \/D = c,d² n, D dt The rate of wear of the average ball is given by dw/dt. dw/dt = c, d² np D lb per hr [5] The weight of the ball charge per unit of mill length is a function of D The number of balls of size d in the ball charge is = f³(D2)/f4(d³). The rate of wear of the total ball charge equals the number of balls times rate of wear of the average ball. Thus rate of total ball wear = — . (dw/dt) w. c, . (l/d) . n,, D lb per hr [6] which is the equation of ball wear in low speed mills. In a mill running at a low speed, grinding is the result of rubbing action within the ball mass and between the ball mass and mill liners. When the speed of the mill is gradually increased toward the critical, the impacting effect of freely falling balls becomes increasingly prominent in comparison with the rubbing action. Reduction of ore takes place partly by rubbing, partly by impact. The share of the freely falling balls in the reduction of ore reaches its practical maximum at a speed somewhat less than the critical; at that speed grinding by rubbing has decreased to a low value. It may be reasonable to think that size reduction by freely falling balls should reach its theoretical maximum at the critical speed, if the fall of the balls were not hindered by the shell of the mill beyond the top point; grinding by rubbing would cease at the critical speed. As a first approximation, wear of freely falling balls may be considered to be a homogeneous, linear function of the force at which they strike pieces of rock and other balls at the toe of the ball charge. The force equals mass times acceleration. The mass of a ball is a function of d3 and its acceleration is a function of the peripheral speed of the mill. The wear of a single ball of size d representing the average ball in a ball charge will therefore be w¹ = f3(F) = f (d3) f7 (v). [7] Indicating that v = D n, and n = c³ np 1/vD, Eq. 7 becomes W1 = cn d3 np Do.5 lb per hr. [8] Total wear of the ball charge equals number of balls times the wear of the average ball. Number of

Jan 1, 1955

By William P. Blake

The literature of the occurrence of quicksilver-ore in the United States does not contain, so far as the writer is aware, any mention of the locality herein described. In the preliminary report * upon the resources of the transPecos region of Texas, von Streerwitz gives a long list of minerals observed as occurring there, but cinnabar is not mentioned. In the second report upon the same region † mention is made of the reported existence of cinnabarite in one of the mountain ranges north of the Sierra Carrizo and the Bofecillos, but the author adds: " In spite of my careful examination of the float, I have not yet found any traces of this metal (quicksilver) up to the present time." Prof. Dumble, also, in * Geol. Surv. of Texas, E. T. Dumble, 1889, p. 225 (first report). † Geol. Surv. of Texas, E. T. Dumble, 1890, p. 713 (second report)

Jan 1, 1896

By J. C. Branner

(New York Meeting, February, 1012.) DURING the past two or three years I have seen statements regarding the first discovery of fullers' earth in this country that seem to require correction or modification. One appears again in the Mineral Resources of the United States for 1909, part II., p. 738, where it is said that ? fullers' earth was first discovered in the United States at Quincy, Fla., in 1893." In this connection the following bit of unpublished history concerning fullers' earth in the State of Arkansas is worthy of attention. In April, 1891, when I was State Geologist of Arkansas, a Swede named John Olsen, formerly a copper-miner in Michigan, but then living south of Little Rock, brought me a sample of what he thought was fullers' earth. He reported that it was from near the town of Alexander, the locality being 1 S. 13 W., section 8, SW. quarter of the SE. quarter. My chemist, Dr. R. N. Brackett, analyzed the material, and reported: Per Cent. Silica, . . SiO2., . 63.19 Alumina, . AL2O3, . 18.76 Iron, . Fe203 7.05 Lime, . Ca0 0.78 Magnesia, . . MgO 1.68 Potash, . K2O 0.21 Soda, . . Na2O 1.50 Loss on ignition, . 7.57 100.74 Water at 110° to 115° C. = 7.84. Another sample from about the same locality, also brought by John Olsen, on analysis by Dr. Brackett gave

Jul 1, 1912

By Hugh Marriott

MANGANESE and its ores have been recently dealt with in comprehensive papers to the Iron and Steel Institute by Sir Robert Hadfield, and in a series of papers read before the A. I. M. E. at the Cleveland meeting. I have taken the opportunity of adding this mineral, to my records of the "World's Mineral Production and Consumption," as recently pub-lished in the Economist ?. The tables bring out the following significant facts: The world's production has increased by 10 per cent since 1913. India's production has increased by 3 per cent since 1.913, the supply from this source now being 31.1 per cent of the world's output. Russia is now producing at about half its pre-war rate and yields 19 per cent of the world's production. West Africa supplies 12.5 per cent of the world's total output. Brazil's present output is 2.5 times that of the pre-war period, being 11.3 per cent of the world's output.

Jan 9, 1927

By David Segura

THE Huitzuco mercury deposits have been described by C. W. Vaupell,1 therefore the general information such as location, history, production, etc. will not be repeated here. The present owners acquired the property when the deep levels of the Cruz mine were flooded, and it was believed that a relatively large tonnage of low-grade ore and fills would be encountered in the flooded section, because of the early mining methods used in the Cruz mine. The mine was partly unwatered and about 187,000 tons of fills was pit-sampled in the San Cayetano stope. These fills average 2.4 kg. Hg per ton. During the period of maximum production at Huitzuco, the ores were sorted in the mine and cobbed into 3-in. pieces, which were treated in Scott furnaces. Large pieces of raw ore are found in the sinter, and it is indicated that both recovery and costs were not very satisfactory. Recent practice has been to treat the ores in closed retorts made of 10-in. pipes. Because of the presence of combined antimony in the mineral livingstonite (HgS.2Sb2S3) and considerable native sulphur, little or no metallic mercury is recovered in the condensers and a second retorting of the condenser muds is necessary. This makes the treatment of the ores expensive and tends to low recoveries of mercury. The principal costs of retorting are, in their relative order: (1) fuel, (2) low recovery of mercury, (3) replacement of retort pipes, (4) labor. METHODS TESTED Three series of experiments have been made, with the object of reducing the costs of recovering mercury and antimony from the ores, by: (1) wet metallurgical methods, (2) bulk roasting in large mechanical furnaces, (3) concentration to reduce the bulk to be followed by roasting in some mechanical furnace. The wet metallurgical methods did not appear feasible because of the high cost of the alkaline solvents used, and investigations of these were not carried beyond the preliminary stage.

Jan 1, 1938

By H. Kosmider, P. Coheur

New processes of blowing with an oxygen-enriched air or gas mixtures of oxygen and steam allow the steelmaker to produce, in a basic converter, a rimmed steel low in nitrogen (0.0020 pct), phosphorous (0.020 pct), and sulphur (0.020 pct). The physical properties (ductility) of the new steels are excellent. Furthermore, from the point of view of economy, these new methods of blowing offer outstanding possibilities. THE natural occurrence of geological deposits of iron ore and local economic circumstances led European blast furnace men to work large quantities of lean iron ore with a phosphorus content as high as 0.5 pct. The iron obtained from these ores generally contains 1.5 to 2.1 pct phosphorus, 3.6 to 3.9 pct carbon, 0.3 to 0.6 pct silicon, 0.04 to 0.08 pct sulphur, and 0.3 to 1.2 pct manganese. To produce steel from this pig iron, the steelmaker has at his disposal several processes. One of the simplest and most economical is the pneumatic process developed by S. G. Thomas in 1879. This process of steelmaking, called the Thomas process, consists of blowing through the bottom of a basic bessemer converter and is used widely in Western Europe, as shown in Table I. Due to the development of tonnage oxygen plants, this process has become more important because the use of oxygen offers new possibilities of steel manufacture. Not only may the quality of the steel be improved, but liquid pig iron also may be used, the composition of which does not meet the heat requirements of the blow with atmospheric air. It is not intended to present here a detailed scientific discussion of the basic bessemer process but rather to discuss briefly its industrial possibilities in the case of rimmed steel and when blowing with atmospheric air, oxygen-enriched air, or gas mixtures of oxygen and steam. This paper is based on the current practice at Klockner-Hüttenwerk Haspe's steel division, and at six Belgian and Luxemburg steel works. The latter are members of the Liege section of the C.N.R.M. (National Institute for Metallurgical Research) and are: ARBED, John Cocker-ill, Esperance-Longdoz, HADIR, Miniere et Metal-lurgique de Rodange, and Ougree-Marihaye, most of which are working with tonnage oxygen plants.' In order to avoid any misunderstanding, it should be noted that most of the techniques to be men- tioned, or similar ones, are used currently at many steel plants in Western Europe. Background The basic converters used in Europe have a capacity of 17 to 65 tons of steel, and are similar in shape to the one in Fig. 1. The lining is brick or rammed dolomite and has a life of 250 to 500 blows. The bottom is rammed dolomite and has a life of 40 to 80 blows. As far as we know, the type of blast used does not appear to have any influence on the life of the lining. Bottom life, on the contrary, depends very much upon the composition of the blast. It is only when

Jan 1, 1955

EXECUTIVE COMMITTEES OF LOCAL SECTIONS New York L. W. FRANCIS, Chairman, WILLARD S. MORSE, Vice-Chairman. THOMAS -T. READ, Secretary, Woolworth Bldg., New York: N. Y. P. A. MOSMAN, Treasurer. LOUIS D: HUNTOON. Boston HENRY L. SMYTH, Chairman. ALFRED C. LANE, Vice-Chairman. AUGUSTUS H. EUSTIS, Secretary-Treasurer, 131 State St., Boston, Mass. TIMOTHY W. SPRAGUE, HENRY A. WENTWORTH. Columbia F. A. THOMSON, Chairman. GEORGE W. RODDEWIG, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. R. S. McCAFFERY, S. H. RICHARDSON.

Jan 10, 1914

C. D. Demond, Anaconda, Mont. (communication to the Secretary*) :—In order to throw some light on this interesting subject, a series of experiments were made with strips of mild steel, containing about 0.14 per cent. of C and 0.22 per cent. of Ma. These strips were thoroughly cleaned and brightened before use, salts were added to distilled water until it corresponded as nearly as possible to the analysis given by Mr. Lee, and in this water at different temperatures were placed four strips of steel; while four other strips, at corresponding temperatures, were placed in the water used at the Washoe Reduction Works. The latter plant has had no trouble from corrosion of furnace-jackets, pipe-lines or boilers. The analysis of the water used at the Washoe works is: Grains er U. S. Gallon. CaCO3........... 2.92 CaSO3........... 0.76 MgCI3........... 0.64 MgCO3........... 0.58 A1203........... 0.12 Fe2O3........... 0.12 SiO2........... 0.58 NaCl........... 0.35 Organic matter, etc.,........ 1.16 7.23 This water is neutral to litmus; while the artificial Copper Queen water was very slightly alkaline, which Mr. Lee informs us is also true of the water at Douglas. Both waters mere well aerated by pouring from beaker to beaker, and by blowing in air from the experimenter's lungs. The results of these tests, given in Table I., show that there is no significant difference between the effects of the two waters.

Jan 1, 1909

By H. H. Alexander

PRIOR to 1915, numerous attempts were made to treat tin concentrates in the United States, but for various reasons they were unsuccessful. Tin ore is said to have been found in nearly every state, but none of the deposits have proved to be of commercial importance. The only domestic production is in Alaska, but only a few hundred tons annually have been produced; hence any considerable production of tin in the United States must be from foreign ores. The most promising occurrence of tin was found in the Black Hills, S. Dak.; in the early development stage, it was called the Cornwall of America. Associated with the tin is tungsten. The story is told that an exceedingly fine specimen of the Black Hills ore was sent to England to encourage stock promotion; the desired effect was produced until a skeptic chipped off a small piece, which the analysis showed to be wolframite. FIRST ATTEMPTS AT SMELTING One of the first promising attempts at tin smelting in the United States was made by R. T. White at Bayonne, N. J., in 1903. Mr. White, after spending some time in England studying the methods of tin smelting, organized a company called the International Tin Co., and erected a plant to treat tin concentrates from the Straits of Malacca. About the time the plant was completed, the English Government placed an export duty of 40, per cent. ad valorem on tin .concentrates exported to other than British smelters, which duty made it impossible to operate this plant so the enterprise was abandoned. As this export duty is still effective, the only source of tin-ore supply for 'the United States is the Bolivian concentrates.

Jan 3, 1924

By J. R. Stack, H. H. Alexander

Prior to 1915, numerous attempts were made to treat tin concentrates in the United States, but for various reasons they were unsuccessful. Tin ore is said to have been found in nearly every state, but none of the deposits has proved to be of commercial importance. An annual output of a few hundred tons in Alaska is the only domestic production; hence any considerable production of tin in the United States must be from foreign ores. The most promising occurrence of tin was found in the Black Hills, S. Dak.; in the early development stage, it was called the Cornwall of America. Associated with the tin is tungsten The story is told that an exceedingly fine specimen of the Black Hills ore was sent to England to encourage stock promotion; the desired effect was produced until a skeptic chipped off a small piece, which the analysis showed to be wolframite. First Attempts at Smelting One of the first promising attempts at tin smelting in the United States was made by R. T. White at Bayonne, N. J., in 1903. Mr. White, after spending some time in England studying the methods of tin smelting, organized a company called the International Tin Co., and erected a plant to treat tin concentrates from the Straits of Malacca. About the time the plant was completed, the English Government placed an export duty of 40 per cent. ad valorem on tin concentrates exported to other than British smelters, which duty made it impossible to operate this plant so the enterprise was abandoned, As this export duty is still effective, the only source of tin-ore supply for the United States is the Bolivian concentrates. Bolivian Tin Concentrates Unlike the alluvial placer deposits, nearly all Bolivian tin occurs in lode deposits and some of the highest grade ores contain only a small

Jan 1, 1924

By J. C. Branner

DuriKg the past two or three years I have seen statements regarding the first discovery of fullers' earth in this country that seem to require correction or modification. One appears again in the Mineral Resources of the United States for 1909, part II., p. 738, where it is said that 'fullers' earth was firat discovered in the United States at Quincy, Fla., in 1893." In this connection the following bit of unpublished history concerning fullers' earth in the State of Arkansas is worthy of attention. In April, 1891, when I was State Geologist of Arkansas, a Swede named John Olsen, formerly a copper-miner in Michigan, but then living south of Little Rock, brought me a sample of what he thought mas fullers' earth. He reported that it was from near the town of Alexander, the locality being 1 S. 13 W., section 8, SW. quarter of the SE. quarter. My chemist, Dr. R. N. Brackett, analyzed the material, and reported: Per Cent. Silica,.....SiO2 .... 63.19 Alumina,.... A12O3 .... 18.76 Iron,.....Fe2O3 .... 7.05 Lime,.,...CaO .... 0.78 Magnesia,.... MgO .... 1.68 Potash,.... K2O ,... 0.21 Soda,.....Na2O .... 1.50 Loss on ignition,........7.57 100.74 Water at 110° to 115° C. = 7.84. Another sample from about the same locality, also brought by John Olsen, on analysis by Dr. Brackett gave :

Jan 1, 1913

By E. C. Pechin

AT the suggestion of some members of the Institute, attention is called to the record of the working of Dunbar Furnace during the twelve months ending in January, 1874. During this period, with a product of over eleven thousand gross tons, not a single ton of

Jan 1, 1874

By R. W. Raymond

The death of Louis Janin, which took place Mar. 6, 1914, at Santa Barbara, terminated the earthly career of almost the last survivor, and one of the most illustrious members, of that group of American mining engineers and metallurgists who, in the last quarter of the nineteenth century, directed the development of the mineral resources of the Pacific slope. Louis Janin was born in 1836 at New Orleans. His grandfather, an officer in the French army, had emigrated to this country, with his family, at or before the outbreak of the French revolution. His father became an

Jan 1, 1915

By C. A. LINDBERG

Several new methods have been developed on the Iron Range to remove the material adhering to truck bodies in freezing weather. A machine known as a Gradall, incorporating the features of digging both above and below the horizontal, digging angle of blade control, full revolving, travel almost anywhere, and operated by one man, has proven successful in trials at body cleaning. Several of these units are in use with great saving in box-cleaning costs and improvements in efficiency of the truck operation with full capacity boxes. In addition to their winter use, the same machines have been used for ditching and excavating in the summer with great saving. The latest method of combating this freezing problem is to carry the exhaust from the engine through the body, making use of the tremendous heat that is now being wasted. To do this, the present wood sandwich which is used between the bottom of the box and the wear plate is removed and replaced with angles or channels run lengthwise of the box and spaced to permit gases to flow between or through them and also provide a good sup- port for the wear plate. The channels or angles are cut a little short on each end to form a cross passage that permits the gases to flow through the area. In the front end, openings are made in the wear plate and connect to a manifold created by welding a plate across the whole front of the box, spaced from the original end by the original vertical reinforcing angles at that point. The body being described is for a Euclid truck which is the only truck that has been adapted to this body-heating idea to date. At the rear of the truck, the holes from the cross passage are made in the bottom plate of the body and lead into a triangular-shaped body cross member under the scoop end of the truck.

Jan 1, 1949

By W. B. Mather

Arkansas' nonmetalliferous deposits are of many different types. The principal types briefly described in this paper are: clays, shales and slates; silica deposits; limestone and dolomite; barite; gypsum; celestite; nepheline syenite; greensand; phosphate; vermiculite; fuller's earth; bentonite; diamonds; sand and gravel. The future development of these deposits is expected to effect profoundly the industrial development of the state.

Jan 5, 1950

By John C. Calhoun, R. C. Newman

A report is made of experimental work performed on the capillary retention of water within porous solid systems, the displacement being accomplished with air and various organic liquids. A portion of the experiments were designed to measure the lowering of vapor pressure of water within a porous solid with subsequent conversion of such vapor pressure data to capillary pressure values. The form of the capillary pressure curve at high capillary pressures has been elucidated from this data. Certain theoretical approaches are presented to indicate the correlation between work done by previous investigators. The present work is correlated also with theory. Surface area values are calculated for the various core systems studied. INTRODUCTION Leverettl in 1941 presented a paper which gave the essential concepts of capillary behavior in porous solids. His presentation included both theoretical and experimental aspects of the problem. He defined the term "capillary pressure" and applied it to an ideal porous system. His work included the definition of a dimensionless quantity which was a function of fluid saturation and which could be correlated with porosity and permeability for clean, unconsolidated sands. His experimental work was performed by the drainage of water from packed columns of unconsolidated sands. Subsequently, other authors have presented experimental techniques which permit the determination of capillary pressure data on small core samples. Data have been presented on porous systems other than unconsolidated sand and with the use of liquids other than water. Notable among these are the works of Hassler, Brunner and Deahl,2 Bruce and Welge,³ Amyx and Yuster, and Purcell. Others have indicated the applicability of such data to field problems without regard to the theoretical aspects of the capillary pressure saturation function. Within the recent published literature there have also been reported studies of the correlations between capillary pressure data and other fundamental properties of porous solids. It was the intent of the present reported work to investigate the behavior noted by water and various other liquids within porous systems in an attempt to amplify existing correlations between capillary properties, surface properties, and other fundamental characteristics of porous systems. The experimental work described here was performed as two different investigations but due to its nature it is reported as separate phases of the same general topic. CAPILLARY PRESSURE AND VAPOR PRESSURE LOWERING It has long been recognized that the vapor pressure above the curved surface of a liquid is a function of the curvature of the liquid surface." The capillary pressure is also a function of the curvature of the liquid surface. Both capillary pressure values and vapor pressure lowering are, therefore, functions of the liquid saturation of a porous solid. A quantitative relationship between the vapor pressure lowering and the capillary pressure can be simply developed by considering a porous solid system containing water in equilibrium with its vapor. The capillary pressure at any height within the system is defined as Pc= Pv -P1.......(1) where PI is the pressure in the vapor phase and PI is the pressure in the liquid phase. Consider that both the water and its vapor are continuous phases within the system and that at any point the two phases are in equilibrium. The gradients in the liquid and vapor columns within the porous system are: PI = plgdh dPv = pvgdh By integrating these gradients from the point where h = 0 to the height h, values of PI and PI at the point h are found. Let the point where h = 0 be that where Pc = 0. At this point also Pv is equal to Pve, the equilibrium vapor pressure of the liquid above a flat surface. From the first of these integrations since p is independent of height: P = p1gh + P, From the second, by substituting pv = PvM/RT, where M is the molecular RT weight: Pv M Pvo- RT gh By combining the two last equations to eliminate h, one obtains: P1 RT Pv Substituting, values for Pv and Pi in equation (1) gives PyRT RT Pv which is approximately Pc=RT/Mp1 In Pvo/Pv .......(2) This equation relates the vapor pressure above a curved surface with the capillary pressure across the curved surface in terms of measurable quantities. The equivalent of this equation is given by Freundlich."

Jan 1, 1949

By John C. Calhoun, R. C. Newman

A report is made of experimental work performed on the capillary retention of water within porous solid systems, the displacement being accomplished with air and various organic liquids. A portion of the experiments were designed to measure the lowering of vapor pressure of water within a porous solid with subsequent conversion of such vapor pressure data to capillary pressure values. The form of the capillary pressure curve at high capillary pressures has been elucidated from this data. Certain theoretical approaches are presented to indicate the correlation between work done by previous investigators. The present work is correlated also with theory. Surface area values are calculated for the various core systems studied. INTRODUCTION Leverettl in 1941 presented a paper which gave the essential concepts of capillary behavior in porous solids. His presentation included both theoretical and experimental aspects of the problem. He defined the term "capillary pressure" and applied it to an ideal porous system. His work included the definition of a dimensionless quantity which was a function of fluid saturation and which could be correlated with porosity and permeability for clean, unconsolidated sands. His experimental work was performed by the drainage of water from packed columns of unconsolidated sands. Subsequently, other authors have presented experimental techniques which permit the determination of capillary pressure data on small core samples. Data have been presented on porous systems other than unconsolidated sand and with the use of liquids other than water. Notable among these are the works of Hassler, Brunner and Deahl,2 Bruce and Welge,³ Amyx and Yuster, and Purcell. Others have indicated the applicability of such data to field problems without regard to the theoretical aspects of the capillary pressure saturation function. Within the recent published literature there have also been reported studies of the correlations between capillary pressure data and other fundamental properties of porous solids. It was the intent of the present reported work to investigate the behavior noted by water and various other liquids within porous systems in an attempt to amplify existing correlations between capillary properties, surface properties, and other fundamental characteristics of porous systems. The experimental work described here was performed as two different investigations but due to its nature it is reported as separate phases of the same general topic. CAPILLARY PRESSURE AND VAPOR PRESSURE LOWERING It has long been recognized that the vapor pressure above the curved surface of a liquid is a function of the curvature of the liquid surface." The capillary pressure is also a function of the curvature of the liquid surface. Both capillary pressure values and vapor pressure lowering are, therefore, functions of the liquid saturation of a porous solid. A quantitative relationship between the vapor pressure lowering and the capillary pressure can be simply developed by considering a porous solid system containing water in equilibrium with its vapor. The capillary pressure at any height within the system is defined as Pc= Pv -P1.......(1) where PI is the pressure in the vapor phase and PI is the pressure in the liquid phase. Consider that both the water and its vapor are continuous phases within the system and that at any point the two phases are in equilibrium. The gradients in the liquid and vapor columns within the porous system are: PI = plgdh dPv = pvgdh By integrating these gradients from the point where h = 0 to the height h, values of PI and PI at the point h are found. Let the point where h = 0 be that where Pc = 0. At this point also Pv is equal to Pve, the equilibrium vapor pressure of the liquid above a flat surface. From the first of these integrations since p is independent of height: P = p1gh + P, From the second, by substituting pv = PvM/RT, where M is the molecular RT weight: Pv M Pvo- RT gh By combining the two last equations to eliminate h, one obtains: P1 RT Pv Substituting, values for Pv and Pi in equation (1) gives PyRT RT Pv which is approximately Pc=RT/Mp1 In Pvo/Pv .......(2) This equation relates the vapor pressure above a curved surface with the capillary pressure across the curved surface in terms of measurable quantities. The equivalent of this equation is given by Freundlich."

Jan 1, 1949

By Joseph B. Darby, Paul A. Beck

IN isothermal sections of several ternary systems, the a-phase was found1 to extend in the form of a relatively narrow elongated field, connecting the U-phases that are present in the adjoining binary systems. This was interpreted in accordance with the conception that the U-phase is an electron compound and the ternary U-phase fields were shown in several systems' to extend approximately in the direction of constant average d-shell electron vacancy number per atom. ' However, in the various isothermal sections of the Fe-Cr-Mo system" the ternary a-phase field was

Jan 1, 1958