bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Relation between Composition and Swelling in Clays
Authors: Foster Margaret D. 
Published: August 2006

AbstractThe phenomenon of swelling is associated with the hydration of clay; however, all clays do not swell when hydrated. Steps in the mechanism of hydration and swelling of different types of clays as observed and interpreted by several investigators and some theories proposed as to the cause of hydration and swelling are reviewed.The concept of clays as colloidal electrolytes that dissociate to a greater or less extent when dispersed in water seems to explain most satisfactorily the significant relation between the degree of swelling on hydration and the composition of the clay minerals. In the kaolinite group, in which there are generally no replacements, the small number of exchangeable cations associated with the clay structure are presumed to be held by broken bonds on the edges of the sheets. Even though kaolinite, as shown by Marshall, is more highly ionized than montmorillonite, this greater ionization, because of the small number of cations present and their location on the edges of the sheets, cannot pry the units apart or leave the sheets sufficiently charged to cause the mineral to exhibit the phenomenon of swelling.In the montmorillonite structure, on the other hand, isomorphous replacements, most commonly of magnesium and ferrous iron for aluminum in the octahedral layer, and, to a slight degree, replacement of aluminum for silicon in the tetrahedral layer, give the structure a net residual charge of 0.7 to 1.10 milliequivalents, which is neutralized by cations held electrostatically and located, for the most part, between the sheets. On hydration such a structure tends to ionize, the degree of ionization depending on (a) the nature of the exchangeable cation and (b) the kind and extent of isomorphous replacements. The characteristically great swelling of sodium montmorillonite as compared with calcium montmorillonite can be correlated with its much greater ionization. The differences in swelling of different montmorillonites have been correlated with the nature and extent of octahedral substitution and are attributed to the effect of these replacements on the anionic strength of the structural unit and its consequent degree of ionization as influenced by the changes in polarization throughout the structure caused by these replacements.Hydrous mica, with the same structure as montmorillonite, is characterized by even a greater degree of isomorphous replacements and, consequently, a greater charge. However, a large part of this charge is neutralized by fixed, nonexchangeable and nonionizable potassium, and ionization of the exchangeable cations is unable to overcome the effect of this fixed potassium. It is probable that the greater replacements in the hydrous mica structure, as in the montmorillonite structure, have a depressing effect on ionization. The result is that hydrous micas are characterized by a very low degree of swelling.
Clay Minerals in Petroleum Reservoir Sands and Water Sensitivity Effects
Authors: Dodd C. G. , Conley F. R. , Barnes P. M. 
Published: August 2006

AbstractThe ability of some petroleum reservoir sands to conduct oil is decreased by interaction of the porous rock with water, usually water fresher than that coexisting with oil in rock interstices. Shales penetrated by drilling operations may swell upon interaction with relatively fresh water drilling liquids. The question of the relation of specific clay mineral content to reservoir sand water sensitivity has not been investigated in detail by other workers, although bentonitic clays often have been considered responsible.A selection of 90 core samples from widely scattered American oil fields has been analyzed for clay mineral content. Reservoirs of known water sensitivity history and others where no such problem exists are represented by the samples. Modern X-ray diffraction techniques were employed to determine clay mineral types, lattice expandability, and approximate amounts present. The main purpose was to test the hypothesis that there exists a direct relationship between content of 3-sheet, glycerol-expandable clay minerals and water-sensitive behavior.It was found that water sensitivity can be predicted with surprising accuracy by measuring the intensity of the X-ray diffraction peak of the glycerol-expanded basal plane spacing. Samples producing “moderate” or greater intensities of the glycerol-expanded peak were taken from sands that exhibited economically serious water-sensitive behavior. Large concentrations of nonexpandable kaolin, chlorite, and mica clay minerals did not produce serious water sensitivity effects in the absence of expandable minerals.A selection of samples from West Texas sands of Permian age were the only samples older than the Mesozoic found to contain expandable clay minerals. These expanded anomalously, possibly as a result of interstratification. The characteristic clay mineral suite might be employed as a geological marker to identify the Yates and Queen sands over a wide geographical area in Pecos, Ward, and Winkler counties of West Texas.A possible mechanism of the swelling of clay particles lining reservoir rock pores is discussed in terms of osmotic and Donnan membrane effects as applied to intraparticle swelling. The swelling of expandable clay mineral particles upon contact with relatively fresh water is postulated as the most general cause of water sensitivity difficulties encountered in petroleum production operations. Swollen particles restrict flow in rock pores, and minute, expanded lamellae break away to be dispersed in water within a pore and restrict flow further when they lodge in pore constrictions. Non-expandable clay mineral grains do interact specifically with water but are incapable of swelling and disintegrating to the same degree as those grains containing expandable minerals.
A Method for the Determination of the Cation Exchange Capacity of Clay Minerals and Soils
Authors: Frysinger Galen , Thomas Henry C. 
Published: August 2006

AbstractFor many purposes it is desirable to have a method for the determination of the cation exchange capacity of clay minerals based on principles as free from ambiguity as possible. Most of the many methods previously proposed have the drawback of entailing a great deal of work if one is to make sure that the mineral is completely saturated with the reagent in use, or that an excess of the reagent is absent. What might be called the complete chromatographic method by its very nature does not suffer from this difficulty. A known weight of clay is suspended on an appropriate inert filter aid (such as Gooch asbestos), packed into a glass tube, and the exchangeable ions eluted with a solution of cesium chloride traced with radioactive Cs 137. The effluent is collected in a series of appropriately sized samples, and the specific radioactivity of each of these determined. When the activity of the effluent has risen to that of the influent solution, one is certain that complete exchange has taken place. A simple computation gives the total cesium holdup of the column, and if the column was initially dry, the exchange capacity of the clay sample.As a routine method, particularly when results of the highest precision are not needed, the effluent may be collected in only two samples, one large sample and finally one small sample to check for complete exchange. This procedure requires a minimum of work and attention but suffers from the disadvantage that the result depends upon the difference of the two counting rates measured and is thus subject to greater uncertainty.These methods have been compared with the Bower-Truog method (Ind. and Eng. Chem., Anal. Ed., 12, 411 (1940)) on Chambers, Arizona, montmorillonite, a nontronite, and an attapulgite. Generally the Bower-Truog method gave more variable and somewhat lower results. Thus for the Chambers montmorillonite the Bower-Truog method gave 0.97 meq./gm.; the chromatographic method, 1.054 meq./gm.The method has been further tested by initially saturating columns with manganous ion, determining the weight of solution held up in the column, and then eluting with traced CsCl. Effluent Mn was determined colorimetrically and the Cs in the Geiger counter. The results agreed within experimental error for the following clays of the API series: montmorillonites H19, H23, H24; illite H36; and nontronite H33b.
H-Ion Catalysis by Clays
Authors: Coleman N. T. , McAuliffe Clayton 
Published: August 2006

AbstractAcid clays prepared by electrodialysis or by treatement with dilute (< about 0.1N) mineral acid solutions were largely Al-saturated, and had little catalytic effect on ester hydrolysis and sucrose inversion. On the other hand, clays exhaustively treated with cold 1N HCl were largely H-saturated, and served as effective H-ion catalysts. When various quantities of clay were used as catalysts, reaction rates were proportional to the concentration of H-ions in the system.H-montmorillonites prepared from Plymouth, Utah bentonite and from Volclay bentonite were from 50 to 200 percent more effective catalysts for ethyl acetate hydrolysis than was HCl. For sucrose inversion, <2 μ H-clays had a somewhat greater catalytic effect than did HCl, while clay aggregates were much less effective catalysts. For ester hydrolysis, the degree of dispersion of the clay made little difference in its catalytic activity.
Lattice Expansion and Rheological Behavior Relationships in Water-Montmorillonite Systems
Authors: Foster William R. , Savins J. G. , Waite J. M. 
Published: August 2006

AbstractSome divergent experimental data have been reported on the swelling behavior of sodium montmorillonite. At water contents above 50 percent (based on the weight of dry clay) the basal reflection of sodium montmorillonite at 19.2 Å becomes weak and very diffuse; some workers have stated that it disappears altogether while others report a persistent weak line even at very high water content. The pronounced differences in physical properties of sodium and calcium montmorillonite suggest that their lattice expansions should also be dissimilar. This paper describes some X-ray diffraction experiments using purified lithium, sodium, and potassium montmorillonites dispersed in water and in salt solutions which were conducted for the purpose of resolving some of these disputed points. The X-ray diffraction instrument employed was a General Electric geiger counter spectrometer unit with a copper tube and nickel filters. The knowledge thus gained has provided some insight into other properties of these clays, such as their rheological behavior.A recording Couette-type viscometer designed to provide a wide spectrum of shear rates and shearing stresses has been used to examine the rheological transformations which occur in passing from states of maximum dispersion to states of varying degrees of agglomeration as a result of interactions between LiCl, NaCl, KCl, and CaCl2, and the Li, Na, K, and Ca salts of montmorillonite in terms of certain ideal rheological models. Filtration characteristics of these systems have also been explored using a standard technique.
Method of Screening Chemical Bonding Agents for Clay Soils
Authors: Rodes V. H. 
Published: August 2006

AbstractThe constant consideration, punctuated by periods of almost frantic concentration of effort and by periods of dull lassitude, given to chemically bonding soil particles into structural materials has yielded some useful products, some laboratory curiosities, and some ideas as to how current and future efforts may be more meaningfully evaluated. Current work indicates that attempts to evaluate chemicals for bonding clay soils are significantly clouded by: (1) lack of knowledge of the soil-chemical bond; (2) lack of knowledge of the type of soil surface susceptible to bonding; (3) lack of knowledge of the inhibitors to chemical reactions present in soil systems; (4) lack of a correlation of the differences in response to treatment between readily indentifiable clays and soil fractions apparently composed of these clays; and (5) lack of satisfactory laboratory techniques by which rapidly reacting chemicals can be properly incorporated with soils.A program is proposed whereby standards of response to treatment are established for different categories of known bonding agents when used with fractionated silica, kaolin and kaolinitic soils, montmorillonite and montmorillonitic soils. A device suitable for laboratory use in this program is suggested.
Some Hydrous Micas in South African Clays and Shales
Authors: Heystek H. 
Published: August 2006

At the 4th International Soil Science Congress held in Amsterdam (1950) a special meeting discussed the nomenclature of clay minerals and suggested “hydrous mica” as a general term for those clay minerals that are neither well crystallised micas nor pure expanding minerals.In the past various names have been used for the hydrous micas. As early as 1912, Galpin, and later, in 1920, Bayley, introduced the terms “hydro-mica” and “hydrous mica” respectively, to designate a micaceous clay mineral. Since then, reports have been made of the presence in soils of a potash-bearing clay mineral (Wherry et al., 1929), and in clays of a mica-like clay mineral (glimmerartige Tonmineralien) (Endell et al., 1935), and a sericite-like mineral (Grim, 1935). In 1937 Grim et al., for the first time proposed the term “illite” as a “general term for the clay mineral constitutents of argillaceous sediments belonging to the mica group.” Other names include bravaisite (Ross and Hendricks) and sarospatite (Maegdefrau and Hofmann, 1937), but the validity of these as specific minerals is questionable since they have been found to exist as mixtures of hydrous micas and montmorillonoids (Bradley, 1945; Brindley, 1951).
The Clay Mineral Composition of Representative Soils from Five Geological Regions of Texas
Authors: Kunze G. W. , Templin E. H. , Page J. B. 
Published: August 2006

AbstractMineralogical studies for the <2 μ fractions are presented for seventeen soil profiles and two surface horizon samples, which represent eight soil types and five geological regions in the state. There was no evidence of clay mineral formation in the upper 6 feet or more of soil. X-ray diffraction data from the Lufkin, Ruston and Katy soils suggested some decomposition of montmorillonite and kaolinite in the upper horizon. However, the overall picture is one of little change in clay mineral composition between the soils and parent sediments.
Chemical, Physical, and Mineralogical Properties of Certain Soil Profiles in the Lower Mississippi Delta
Authors: Driskell B. N. 
Published: August 2006

AbstractThe soils of the lower Mississippi Delta are derived from the Mississippi or Red River depositions or some combination of these two.Profiles of the Iberia, Baldwin, Buxin, Sharkey, and Mhoon were selected for the study. The comparative results indicate that the Sharkey was highest in cation exchange capacity and exchangeable calcium and magnesium. Base saturation was highest in the Iberia and lowest in the Baldwin. The variation in cation exchange capacity was possibly due, in general, to the differences in texture, except for the Iberia. The clay fraction of the Iberia contained slightly larger quantities of high cation exchange capacity minerals than the other soil series of the study.Silica was highest in the Baldwin while the oxides of aluminum, iron, magnesium, and potassium were highest in the Buxin. Iberia was highest in calcium oxide. Silica-sesquioxide and silica-ferric oxide ratios were highest in the Sharkey and lowest in the Buxin. The silica-alumina ratio was highest in the Baldwin and lowest in the Buxin. The comparison of the Buxin with soils of the Mississippi River deposition indicates that the Red River depositions were generally lower in silica-sesquioxide ratios and total calcium oxide and higher in total magnesia and potash.The X-ray patterns indicate that montmorillonite and illite were the dominant clay minerals present. The greatest quantities of montmorillonite were generally found in the Iberia profiles, although this was not always true. Also, in general, the content of montmorillonite increased and illite decreased with profile depth. Secondary minerals were halloysite, kaolinite, vermiculite, and chlorite. The cation exchange capacity of the clay fraction also indicated the higher content of montmorillonite or associated minerals in the Iberia than in the Buxin, Baldwin, Sharkey or Mhoon soils.
Argillation of Three Silicate Rocks Expressed in Terms of Ion Transfer
Authors: Keller W. D. , Kiersch G. A. , Howell Paul 
Published: August 2006

AbstractThe transfer of ions during the weathering of a Medford diabase, a granite from British Guiana, and of the Cheto Arizona tuff is traced by recasting the analyses of the fresh rocks and their altered counterparts into 160-oxygen rock cells, and by comparing algebraically the products of the weathering reaction with the original reactants.Hydrolysis and hydration are the first steps in the reaction. H ions were added in the weathering environment of the diabase and granite, but Mg ions were added in the change of tuff to bentonite.Silica and alkali metal ions are dissolved and removed during weathering of the diabase and granite, presumably under acid conditions, but it appears that the Cheto tuff was formed under a non-acid environment where Mg was added. During the hydrolysis of silicate rocks, H ions are concentrated temporarily in the clay minerals on land, while OH ions go to the ocean.More examples of ion transfer during weathering than the three given herein are needed to define the reactions occurring in the many environments of alteration which rocks encounter.
Clay Mineral Studies of Some Recent Marine Sediments Off the North Carolina Coast
Authors: Murray Haydn H. , Sayyab Abdullah S. 
Published: August 2006

AbstractStudies of Recent marine sediments from the North Atlantic Ocean were made in order to understand better the effects of diagenesis on the clay minerals. Samples from the continental shelf, the continental slope and the floor of the northwestern basin, north of Bermuda, were made available through the courtesy of the Lamont Geological Observatory of Columbia University.Most of the argillaceous material in these sediments is a poorly crystalline, complex mixture of chlorite and illite. The samples contain a small amount of kaolinite and montmorillonite. Some of the problems involved in the identification of these complex mixtures are discussed. Studies of the clay minerals reveal that a slight diagenetic change takes place, as indicated by the increasing crystallinity of chlorite and illite, with increasing depth below the clay-water interface and with increasing water depth. Some of the cores contain zones of red clay and the clay minerals contained therein are relatively well crystallized materials in contrast to the clay minerals in the greenish-gray clays. An hypothesis based on the oxidation state of the iron is advanced to explain the differences between the crystallinity of the three layer clay minerals in the red and greenish-gray clays.
The Effect of Clays on the Permeability of Reservoir Sands to Waters of Different Saline Contents
Authors: Baptist Oren C. , Sweeney S. A. 
Published: August 2006

AbstractThe average results of air- and water-permeability determinations are given for petroleum-reservoir sands in three Wyoming fields. The average amounts of materials of clay size in the sands and the types of clays present, as identified by X-ray diffraction methods, are also presented and discussed.The sands are shown to be more permeable to air than to brines and more permeable to brines than to fresh water. Each of the sands exhibited different behavior when wetted by waters, and the percentage loss of permeability to waters, as compared to air, varied from sand to sand. The sand containing kaolins, illites, and mixed-layer clay (illite-montmorillonite) was found to be the most sensitive to water, and the sand containing only small amounts of kaolins and illites was the least sensitive. The sand that contained the most kaolins and illites was intermediate in water sensitivity. The water-permeability behavior of the sands and the dependence of this behavior on the clays present and the salinity of the water are discussed.
Measurement of Moisture Content and Density of Soil Masses Using Radioactivity Methods
Authors: Goldberg Irving , Trescony L. J. , Campbell J. S. , Whyte G. J. 
Published: August 2006

AbstractThis paper deals with the application of methods involving the scattering of neutrons and gamma rays to the measurement of moisture content and density of granular materials. The measurement of moisture content is based on the principle that when fast neutrons emitted from a radioactive source collide with hydrogen atoms they are slowed down to a much greater extent than by collisions with other atoms. The number of slow neutrons thus produced is a measure of the number of hydrogen atoms present in the vicinity of the source. Water is the principal contributor of hydrogen atoms in a soil medium. A probe, containing a source of fast neutrons and a slow neutron detector, is inserted into the soil. The probe is connected by a cable to a suitably calibrated scaling instrument, and the moisture content determined from the count rate.The density of a soil is measured with a probe that is similar but provided with a source and a detector of gamma radiation. The gamma rays emitted from this source are scattered by collisions with electrons of atoms in their path. The higher the density of the surrounding medium, the greater the scattering. In the range of densities normally occurring in soils, greater scattering results in fewer gamma rays returning to the detector. Thus, the density of the medium can also be related to the count rate obtained with the scaling instrument.The advantages of the radioactivity methods are that continuous or repeated measurements of moisture content and density at any desired depth can be made, and that measurements are integrated over a large volume of soil, so that representative values are obtained. In addition, water may be detected in the solid or vapor states as well as in the liquid state. The soil undergoes a minimum of disturbance because the probe is lowered into an access tube slightly greater than 1 inch in diameter. Measurements can be made in a short time; once the access tube has been placed, it takes an average of about six minutes to determine both moisture content and density at a given depth. The instruments are not influenced by ordinary temperature changes. The method appears to be relatively independent of soil type, so that a single calibration curve for moisture content, and one for density, may be applicable to a wide range of materials.A description of the theory of scattering of neutrons and gamma rays is included in this report as well as a discussion of the various types of sources and detectors which can be employed in the procedure. Field and laboratory tests utilizing these instruments are described, and the accuracy of test results discussed.It is concluded that application of this method will provide a rapid, simple and accurate means for measuring moisture content and density of soils or similar granular materials. On this basis, recommendations for future research and more extensive applications of the method are reviewed.