bluuebunny/crossref_metadata_2025 huggingface dataset:
The Relation between Composition and Swelling in Clays
Authors: Foster Margaret D.
Published: August 2006

The 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

The 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

For 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

Acid 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

Some 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

The 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

Mineralogical 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

The 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

The 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

Studies 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

The 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

This 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.
Flow Properties of the Kaolinite-Water System
Authors: Norton F. H.
Published: August 2006

For the last 20 years, the Ceramic Division at the Massachusetts Institute of Technology has been carrying on basic work with the kaolinite-water system. The results have been published from time to time in the Journal of the American Ceramic Society under the title of “Fundamental Study of Clay.”

At the start, it was realized that natutal clays were so complex that it would be impossible to consider them as a basis for quantitative calculations. Therefore, most of our research has been carried out on specially prepared samples taken from the natural clay. These kaolinite samples had a known particle size, were free from organic matter, and had controlled adsorbed ions. In this way, the effect of anyone variable on the rheological properties could be studied in a logical way.
Guide to Field Trip of Fourth National Clay Conference: Clay Minerals in Sedimentary Rocks
Authors: Griffiths J. C. , Bates T. F. , Shadle H. W.
Published: August 2006

Clay minerals occur most commonly as constituents of sedimentary rocks and nearly all the clay mineral species, with the possible exception of nacrite, have been found in sediments. Different clay minerals occur in different kinds of sediments and may be used as one criterion for classifying sediments and interpreting their genesis.
The Colloid Science of Silica and Silicones
Authors: Hauser Ernst A.
Published: August 2006

A detailed explanation of the most important properties of natural and synthetic silica and silica gels is given. Specific reference is made to the differences between the formation of synthetic silica gels and of quartz and cristobalite. The effect exerted by the synthetic products is explained and the importance of their amorphous condition on their reactivity is also referred to. On the basis of ultra- and electron-microscopic studies it is demonstrated that these synthetic products are not crystalline, but amorphous aggregates, and it is also shown how their reactivity can be increased by appropriate dispersion before use.

The colloidal properties of silicone resins are then pointed out and their production explained. Their advantages over purely organic matter and the reasons for this difference are also referred to.

Finally, reasons are given why more attention must be paid to colloid science in any field where silica or silicones are studied or put to use.
The Mechanism of Dehydration of Mg-Vermiculite
Authors: Walker G. F.
Published: August 2006

The hydrated Mg-vermiculite lattice contains double sheets of water molecules interleaved with silicate layers. In the fully hydrated condition, each water sheet is arranged in a regular hexagonal pattern and the interlayer cations are located midway between water sheets in octahedral coordination.

Release of water molecules from interlayer positions leads at first to a gradual contraction of the basal spacing from 14.81 A, during which the water network becomes increasingly distorted. The contraction ceases temporarily at 14.36 A while further water is withdrawn. When the probability that a cation has a complete octahedral “shell” of water molecules at a given instant falls below a certain value, an abrupt contraction to 13.82 A takes place during which the cations are displaced to sites near the silicate layer surfaces.

Release of further water causes a contraction to a lattice (11.59 A) in which single sheets of water molecules are interleaved with the silicate layers. The 11.59 A phase is stable until only a small proportion of the interlayer water remains, when an approximately regular interstratification of 11.59 A and 9.02 A (dehydrated) layers develops. The final traces of interlayer water are retained in the interior of the crystal with great tenacity owing to the sealing of the crystal near the edges.
The Illites from Some Northern Ohio Shales
Authors: Nelson Bruce W.
Published: August 2006

The Middle Paleozoic shales of northern Ohio contain a well-crystallized variety of illite as their main constituent. Powder diagrams relate the illite to the two-layer monoclinic muscovite crystallization. The low asymmetry of the 10 A reflection indicates that inter-layering of non-mica or hydrated-mica units is small. The relative intensities of the basal reflections show that the illites approach the ideal muscovite composition but have about one-fourth the octahedral aluminum replaced by iron and are deficient about one-half or less the interlayer potassium. The interlayer positions are essentially anhydrous. One-dimensional Fourier syntheses made before and after thermal treatment of the illites indicate that intensity changes of the basal reflections due to thermal treatment are related to electron density changes confined to the octahedral layer. Dehydroxylization begins at moderately low temperatures and continues until an anhydride structure is formed.
A Study of the Hydrothermal Reconstitution of the Kaolin Minerals
Authors: Roy Rustum , Brindley G. W.
Published: August 2006

The progressive reconstitution of the thermally decomposed members of the kaolin group (the so-called “meta” phases) has been studied as a function of time, temperature and water vapor pressure of reconstitution, with a view to determining the extent of “pseudomorphism” after the parent structure. The nature of the dehydroxylated dickite which shows a 14A reflection has been investigated further but no additional x-ray data characteristic of a 14A-type structure can be found.

The sequence of rehydration shows that all the meta phases tend to form kaolinite, but the actual sequence of events depends on the parent material. Under the proper conditions well-crystallized kaolinite is obtained from all the meta phases. However, the original minerals themselves could not be converted directly to kaolinite within the time limits of the experiments.
Spanish Investigations on Clay Minerals and Related Minerals
Authors: Albareda J. M.
Published: August 2006

The studies undertaken by the Instituto de Edafologia y Fisiologfa Vegetal on clay minerals and related silicates can be classified into three main groups: (A) Mineralogical identification and crystalline structure: (B) physico-chemical behavior; and (C) technical applications. They are summarized briefly.
Clay-Mineral Research in Belgium (1945–1955)
Authors: Dekeyser W.
Published: August 2006

From 1945 to 1949 clay-mineral studies in Belgium were connected with the Comité Belge pour l’Etude des Argiles, In 1947 this group organized the C. I. P. E. A., which in turn helped to form active national groups of clay workers. Clay-mineral research is now pursued in five laboratories in Belgium. Projects in Brussels include industrial problems, study of reactions of silicates and the oxides of Al, Ca, and Mg; quantitative determinations by x-ray spectrometry; and the use of a differential thermobalance and electron microscopy. Basic clay-mineral problems involving agriculture are being studied at Heverlee, where investigations include studies of fixation of iron on kaolinites and examination of the topography of kaolinite minerals attacked by different reagents. A group at Tervuren has been concerned with formation, deferrization, and determination of oxides by D. T. A. The Laboratoire National des Silicates at Mons is investigating creep phenomena in refractories. The activities of the Ghent group are described in a separate paper.
A Study of an Interstratified Illite-Montmoril Lonite Clay from Worcestershire, England
Authors: MacEwan Douglas M. C.
Published: August 2006

This clay has been studied by Fourier transform methods, which show that it is a random interstratification of mica with montmorillonite, subject however to the limiting condition that montmorillonite layers are never contiguous. It is very similar to one of the mixed-layer clays from Kinnekulle, Sweden, described by Mrs. Byström. The “separation rule” is perhaps one of the factors conditioning the appearance of definite stages in the mixed-layer mica-montmorillonite sequence, as noted by Mrs. Byström.
The Bentonites from the Volcanic Region of Cabo de Gata (Almeria)
Authors: Martin-Vivaldi J. L. , Cano-Ruiz J. , Fontbote J. M.
Published: August 2006

The smectic clay from Sierra de Gata, Cabo de Gata region, Almería, Spain, is montmor-illonoidal like the smectic clay from Serrata de Nijar in the same region. These clays are formed by alteration of calco-alkaline volcanic rocks by marine and/or hydrothermal action.
Clay Mineral Work Proceeding in Japan
Authors: Sudo Toshio
Published: August 2006

Studies on clays in Japan were begun about 1900. Modern clay mineralogical work began about 1940 and is being developed in the following scientific and industrial branches: geology, mineralogy, chemistry, ceramics, soil sciences, soil mechanics, etc. Recent important items are as follows: (a) Order-disorder problems of clay minerals, (b) Studies of clay minerals by electron micrographs and electron diffraction methods, (c) Mixed-layer minerals, (d) Studies on alteration products of volcanic glass, (e) Studies on sedimentary rocks and recent sediments, (f) Clay minerals associated with various kinds of ore deposits, and particularly wall-rock alterations, (g) Soil clay minerals, particularly of volcanic ash soils, paddy soils, etc. (h) Mineralogical and Bolioid-chemical studies of bentonites and acid clays. (i) Clay deposits for ceramic uses, (j) Studies of complexes between clay minerals and organic reagents, (k) X-ray studies on transformation of kaolin minerals.

The results emphasize certain general characters of Japanese clays such as a complex mode of association among clay minerals, or prevalent occurrence of minerals having a lower degree of crystallinity.
Clay Mineral Research in Australia
Authors: Gaskin A. J. , Walker G. F.
Published: August 2006

An account of recent progress and current work is given in a summarized form dealing mainly with clay investigations in C. S. I. R. O., an Australian government research organization.

Although some emphasis is laid on the work designed to identify the nature and assess the properties of clays concerned with building-material manufacture, soils, and ceramics, there are several investigations which deal in a fundamental manner with the crystal structure and surface properties of clay minerals. These items of general interest include projects on the structure of vermiculite, the rehydration and surface properties of kaolinites, the nature and occurrence of Australian illites and attapulgites, and a regular exfoliation effect in montmorillonite suspensions.
Electrokinetic Phenomena in Colloidal Clays
Authors: Oakes D. T. , Burcik Emil J.
Published: August 2006

While the variations of the physical properties of colloidal suspensions of bentonite clays under various conditions of contamination have been the subject of extensive investigations, the role of the associated electrical phenomena in the impartation of these physical properties is virtually undefined. Successful techniques for the measurement of the electrical phenomena have been reported previously but they are applicable only to very dilute clay suspensions in which negligible electrical interference between clay particles exists. Apparatus and techniques applicable to concentrations of colloidal material normally used in bentonite oil-well drilling fluids were developed and are discussed.

Measurement of electrokinetic phenomena in concentrated suspensions was effected by application of the principle of electroosmosis by suitable modification of existing apparatus. The distinguishing modification was replacement of the conventional, consolidated diaphragm with a diaphragm of colloidal material supported by thin membranes.

The applicability of the apparatus and techniques is demonstrated by qualitative comparison with data of previous investigations wherein the comparable depression of the electro-kinetic potential by the addition of various contaminating ions is shown. In addition, the relation between the measured electrokinetic potential and the filtration rate is shown to be linear and independent of the valence or type of contaminant for a major portion of the investigated concentration range. This suggests that for ions which appreciably repress the electrokinetic potential the fluid-loss may be used as a means of approximating the changes of the electrokinetic potential.
Viscosity Studies on Dilute Clay Mineral Suspensions
Authors: Wood W. H. , Gkanquist W. T. , Krieger I. M.
Published: August 2006

A technique has been developed for obtaining reproducible viscometric data on dilute clay suspensions using the recently developed capillary viscometer of Maron, Krieger and Sisko. Aging and type of mixing have important effects on the viscosity of the dispersions. At-tapulgite, hectorite, and Wyoming bentonite exhibit non-Newtonian behavior at all concentrations studied. The effect of temperature on the reduced fluidities of suspensions of the three clays is negligible. In this respect they agree with the behavior predicted for suspensions of rigid, noninteracting particles.
Thermodynamic, Quasithermodynamic, and Nonthermodynamic Methods as Applied to the Electrochemistry of Clays
Authors: Marshall C. Edmund
Published: August 2006

The consequences of a nonhomogeneous charge distribution in clay systems are first examined. The mean ionic activity is shown to be a geometrical rather than an arithmetical average. Potentiometrie methods of measurement, with (quasithermodynamic), and without (thermodynamic) liquid junctions are compared. The latter give chemical potentials of soluble molecular species or ratios of mean activities; neither of these affords a characterization of single cations in relation to clay surfaces. The quasithermodynamic method, like conductance measurements, affords data which can be interpreted directly in terms of single ions. The two are compared for dilute and more concentrated clay systems by using the ratio: “Cation conductivity/total conductivity of clay systems.” For dilute systems this ratio varies slowly and smoothly with concentration and with degree of saturation. High concentrations give an abnormally high value. Cataphoresis results are shown to be in agreement with conductance and Potentiometric data for dilute clay systems.
X-Ray Studies of the Alteration of Soda Feldspar
Authors: Brindley G. W. , Radoslovich E. W.
Published: August 2006

Studies have been made of the alteration of pure albite single crystals and powders. No structural modification of the feldspar itself has been detected. No evidence has been obtained for any preferential orientation of an alteration product in relation to the initial feldspar. Under hydrothermal conditions at 280° C and 430° C., albite flakes and powders have been subjected to attack by 0.1 N HCl for periods ranging from a few hours to 52 days. The flakes changed mainly to boehmite, the powders to a variety of products, including a well-defined kaolinite. This difference of behavior is interpreted in terms of Correns’ ideas on the weathering of silicates.
Effect of Weathering on Clay Minerals
Authors: Murray Haydn H. , Leininger R. K.
Published: August 2006

Types of clay minerals have been determined in samples from three profiles in Indiana: (1) a residual soil from limestone; (2) a Pleistocene till of Illinoian age; (3) a Pleistocene till of Wisconsin, age. The type of clay minerals varies with depth from the surface because of degree of weathering. In the residual soil from limestone, montmorillonite is the dominant clay mineral; the entire profile is highly weathered. Likewise montmorillonite is dominant in the highly weathered portion of both the Illinoian till and the Wisconsin till. The relatively unweathered portion of both tills contains illite and chlorite as dominant clay minerals. The factors of the weathering process in central and southern Indiana evidently favor the development of the clay minerals having expanding lattices. The mechanism for changing chlorite and illite to montmorillonite seems to include oxidation of the iron in the lattice and subsequent leaching of magnesium and potassium.

When surface clays are eroded and transported by streams into a marine environment, the expanding-lattice clay minerals may revert readily to the original type, either chlorite or illite.
Mineral Content and Distribution as Indexes of Weathering in the Omega and Ahmeek Soils of Northern Wisconsin
Authors: Whittig L. D. , Jackson M. L.
Published: August 2006

Quantitative estimation of mineral concentrations was made for the clay fractions of Omega loamy sand (Brown Podzolic) and Ahmeek loam (Brown Forest). These soils are relatively young and have developed from Pleistocene (late Wisconsin) outwash and till, respectively, in northern Wisconsin. A mineral weathering depth function was found, in which iliite and chlorite present at depth have weathered to vermiculite and montmorillonite nearer the surface, particularly in the clay fractions of Ahmeek loam. In the fine clay, the montmorillonite content increases from 5 percent in the C1 horizon to 44 percent in the A1 horizon. Conversely, chlorite decreases from 11 percent in the C1 to virtually none in the A1 horizon. Weathering in these soils is also reflected by distribution of minerals as a function of particle size. The occurrence of mineral-weathering depth and size functions in these young soils is attributed to accelerated leaching made possible by the coarse texture of the soils.
Clay Minerals Research at Ghent University
Authors: Dekeyser W.
Published: August 2006

This contribution reviews the work done at Ghent University, together with some unpublished recent work. Next to the survey of clay minerals from soil samples for the soil mapping organization, the group has been concerned with the polytypism of micas, the alteration and transformation of clay minerals, and the role of migration of iron in mica-type structures under influence of temperature or chemical treatment. A study of growth spirals of biotite crystals threw some light on the origin and possibility of the existence of ordered sequences with great repeat distances, and also on the complexity of crystals of this type. The presence of dislocations in mica is also shown by examination of “bending figures” produced by indentation. A study of clay minerais in soil fractions from a limited area, reclaimed from the sea between the eleventh and nineteenth centuries, indicated great variation in mineral composition. If one accepts the logical working hypothesis that the mineral composition was homogeneously distributed at the start, one must accept a rapid transformation at particular spots. This evolution seems to proceed from muscovite (illite) toward montmorillo-nite. Neoformation of a small quantity of kaolinite accompanies the transformation to mont-morillonite.

Experiments carried out to achieve this process in the laboratory showed that micas submitted to a stream of CO2 dissolve rather rapidly in presence of water. All attempts to obtain clay minerals from the obtained solutions failed, except one, when small quantities of mont-morillonite and kaolinite were formed. The thermal evolution of glauconite and the location of iron ions were also studied. Some remarks on formulas of clay minerals are presented.
Weathering of Mixed-Layer Clays in Soils
Authors: Tamura Tsuneo
Published: August 2006

The occurrence of mixed-layer clays was noticed in several New England soils; a particularly well developed mixed-layer sequence involving the weathering of randomly inter-stratified vermiculite and illite was intensively studied. Weathering of the interstratified system resulted in the formation of alumina in interlayer positions as evidenced by chemical and x-ray tests. The change in “apparent” spacing of the clay was found to be statistically correlated with sample depth which is in turn related to the intensity of weathering. The change in “vermiculite” spacing from 14.2 to 13.9 A was also found to be correlated with depth. The diffraction effects of the interstratified mineral are discussed in the light of the Hendricks and Teller formula and Méring’s refinement of the formula. The evidence points to the alumina being “brucitic” in character; this modifies the curves calculated by Brown and MacEwan for the randomly interstratified 10 to 14 A mineral. The role of interstratification in the process of soil formation is discussed.
Itinerary of Field Trip for Fifth National Clay Conference, October 8, 1956
Authors: White W. A. , Beavers A. H. , Wascher H. L. , Wilson G. M. , Droste J. B.
Published: August 2006

A road log of a 37-mile field trip is presented. The route passed over a group of Early Tazewell moraines and the till plains in between. Stops were made at Flanagan, Drummer and Elliot soil profiles and the type Fithian illite locality. The soil profiles and Fithian cyclothem are described.
Analysis of Consistencies of Kaolin-Water Systems Below the Plastic Range
Authors: Langston Robert B. , Pask Joseph A.
Published: August 2006

Consistency curves and characteristics of Newtonian, pseudoplastic, Bingham body, thixo-tropic and dilatant types of flow are reviewed. The theoretical effects of particle shape on effective hydrodynamic volume and shear resistance for ideal suspensions are considered.

The rheological properties of hydrogen and sodium mono base-exchanged kaolinite clays were determined, using a rotational viscometer, on slips containing up to 50 g solids per 100 g slurry. Changes in rheological properties were also evaluated as a hydrogen slip containing 20 g solids per 100 g slurry was converted into the sodium form.

The discussion includes the effect of differences in charges and charge distribution on the sodium and hydrogen particles and the resulting effects on particle orientation and flocculation. Correction factors for dissociation and particle interference have allowed the use of Einstein’s equation for the viscosity of a suspension up to concentrations of about 40 percent solids for the hydrogen kaolinite system, and about 50 percent solids for the sodium kaolinite system.
Water Vapor Sorption on Lithium Kaolinite
Authors: Torrence Martin R.
Published: August 2006

A sorption apparatus consisting of (1) a high vacuum system (<10−5 mm Hg), (2) an oil manometer to determine the equilibrium vapor pressure, (3) a quartz helix to determine weight of adsorbate, and (4) a constant temperature control for the adsorption chamber has been used to obtain water vapor sorption isotherms on kaolinite. Equilibrium between water vapor and the clay surface can be obtained in 2 hours with this equipment. The estimated error in relative pressure (P/P0) and amount of water adsorbed (X) are ± 0.001 and ± 0.07 mg H2O/g clay respectively. Reproducibility of sorption isotherms for clay samples similarly prepared are within these limits. When retested those clay samples that had stood in the laboratory for a few weeks gave sorption isotherms slightly different from the initial isotherm. This variation, while not excessive, seriously limited interpretation of the sorption data.

In order to study the variation of sorption characteristics with curing conditions, two samples were stored at an elevated temperature (70°C) under two different conditions of moisture content and pressure; one sample as a water slurry (1 g clay per 10 ml H2O) and the other completely dry in an evacuated (<10−5 mm Hg) container. The effect on the sorption isotherms was in both cases very marked but of a different character.

Compared with the sorption behavior of the initial Li kaolinite, the sample stored as a slurry showed greater water adsorption at all values of P/P0 and a disappearance of the marked hysteresis which persists to very low P/P0 on the initial sample; however, when stored in vacuo, Li kaolinite at all values of P/P0 adsorbed less water than the initial Li kaolinite. Data are presented to show that the sample stored as a slurry has been converted to an Al kaolinite. The reduced water sorption upon storage in vacuo is shown to be a permanent change.