bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some Analyses of Soil Montmorin, Vermiculite, Mica, Chlorite, and Interstratified Layer Silicates
Authors: Jackson M. L. , Whittig L. D. , vanden Heuvel R. C. , Kaufman A. , Brown B. E. 
Published: August 2006

AbstractAnalyses were made of 12 clay fractions and one silt fraction taken from 10 different soil horizons and clay deposits. The analyses presented were selected to represent a wide variety of analytical problems with materials containing 2:1 layer silicates, 2:2 (chlorite) layer silicates, varying amounts of 1:1 layer silicates, and in some cases with appreciable amounts of quartz, feldspars, gibbsite, hematite, magnetite, and (or) anatase.The analyses were performed by x-ray diffraction, specific surface, integral heating weight loss, and elemental analyses. The x-ray diffraction analyses included both wedge-powder (film recorded) and oriented (Geiger counter recorded) techniques. Vermiculites of soils were found to vary in the degree to which K-saturation would close the interlayer space, but vermiculite is established by: (a) a 14 A spacing when solvated (even with glycerol); (b) closure of the interlayer spacing on heating to 500° C; and (c) an interlayer surface of about 800 m2 per gm. In the absence of adequate criteria, vermiculites can be mistakenly identified as chlorites.The data obtained from the various techniques were combined by a system of allocation so that the minerals reported represented a unique fit of all the data. The specific surface measurement, including the measurement of interlayer surface, is a key criterion in the allocation. Interstratified (“mixed layer”) layer silicates are determined as the individual component minerals.The beidellite of Iron River and Putnam soil clay finer than 0.08 microns is extensively interstratified with chlorite, mica, and vermiculite. No discrete x-ray crystalline zones of any of the latter three minerals were observed, but a 19.6 to 19.2 A spacing may be indicative of a superlattice of these materials and beidellite with mica and chlorite at the electron density nodes. A titaniferous ceramic clay contains 43 percent mica (as determined by allocating the 5.03 percent K2O to muscovite), 20 percent kaolinite (water loss in 300–525°C range), 21 percent TiO2 and 17 percent of other constituents (by elemental and surface analysis). This occurrence of the full complement of K2O in clay micas (both biotite and muscovite type) is general for the various clays examined, when the interlayer surface is calculated to halloysite, vermiculite, and montmorin. A general occurrence of inter-stratification of layer silicates is proposed.
Base-Exchange: An Analytical Tool for Mixed-Layer Aggregates
Authors: Ormsby W. C. , Sand L. B. 
Published: August 2006

AbstractBase-exchange determinations were made on selected clays of the montmorillonite-illite group to test this method as an analytical tool for the analysis of mixed-layer aggregates. The relatively rapid manganese method developed by Bower and Truog was used and its precision determined on monodisperse, monomineralic fractions and monodisperse fractions of prepared mixtures of illite and montmorillonite. The particle size range 1-0.25 micron was chosen for all determinations exclusive of those on bulk samples.To establish end members, determinations were made on a series of illites, finegrained muscovite and both natural and synthetic montmorillonites.In order to test the validity of this method, determinations were made on mixed-layer aggregates on which illite-montmorillonite percentages had been determined by other workers using x-ray techniques and chemical analysis.
Evaluation of Methods for Quantitative Analysis of Halloysite-Kaolinite Clays
Authors: Sand L. B. , Ormsby W. C. 
Published: August 2006

AbstractA number of methods were tested for their applicability to the problem of determining the content of halloysite in kaolin clays. These analytical methods included the thin-section point-count technique, base-exchange determinations, electron microscope techniques and infra-red absorption spectra differences.Base-exchange determinations were made on a number of monodisperse fractions of pure halloysites and kaolinites. Consistent values of 12 meq/100 g were obtained for the halloysites and 4 meq/100 g for the kaolinites in the size range 1-0.25 micron.Electron micrographs were taken of prepared homogenized mixtures and counts made of the two morphologically different varieties. Application of this technique to several natural halloysitic kaolins, of which the proportions were known by DTA methods, gave good correlative results.The thin section method gave very good results on residual clays where the kaolinite occurs as vermicular aggregates.Infra-red absorption spectra were run by associates on prepared mixtures and the differences were sufficiently marked to give semi-quantitative results.These four techniques are evaluated with respect to accuracy and application and are compared with other reported techniques.
A Mixed-Layer Kaolin-Chlorite Structure
Authors: Brindley G. W. , Gillery F. H. 
Published: August 2006

AbstractA mineral of chlorite-type composition, classified as a daphnite, is shown to give a series of basal x-ray reflections which are incompatible with the normal chlorite structure. Fourier analysis indicates a modified distribution of Si and O atoms. A model is suggested in which some Si atoms are displaced and linked to the adjacent brucite-type layer, producing in effect kaolin-type structural units within the chlorite structure.
X-Ray Study of a New Variety of Serpentine (Ortho-Antigorite)
Authors: Brindley G. W. 
Published: August 2006

AbstractX-ray powder data show an ortho-hexagonal cell containing two structural layers. Close similarity with the data for amesite suggests a similar disposition of the layers within the unit cell. Evidence for a superlattice parameter is obtained indicating a structure similar to that discussed by Aruja and by Onsager.
Electron Micrographic Studies of Clays
Authors: Taggart M. S. , Milligan W. O. , Studer H. P. 
Published: August 2006

AbstractIn order to provide a set of reference photographs to be used in identification studies, electron micrographs at relatively high magnification (40,000 to 132,000 diameters), together with some electron diffraction patterns, have been obtained of a group of (a) kaolinites, (b) halloysites, and (c) South Texas outcrop soil samples. Some of the kaolinites consist of well-formed hexagonal crystal plates with edges still sharp at a magnification of 132,000 diameters. Other kaolinites consist of irregular, relatively thin crystal sheets, which may be bent or folded. In one instance it has been possible to demonstrate that the average thickness of the sheets is only 10 Å. At high magnification the halloysite clay minerals exhibit a structure consisting of rolled sheets, rather than hollow rods. In some cases, it is evident that several separate crystal sheets are coaxially rolled to form multiple concentric hollow tubes. In the South Texas outcrop samples, the morphology is very complex, as the samples do not consist of one uniform type of particle. Matted sheets composed of interlaced bundles of lath-like particles have been observed. These oriented particles exhibit typical “fiber” type electron diffraction patterns. Kikuchi lines were observed in a thin quartz crystal plate, examined for comparative purposes.
Studies of some Vermiculite-Type Clay Minerals
Authors: Hathaway John C. 
Published: August 2006

AbstractX-ray and electron-diffraction studies, and differential thermal analyses of the clay fraction of some soils from Virginia, New Jersey, and Wisconsin indicate an abundance of minerals resembling vermiculite. Measurements of the 060 spacing for these minerals give values lower than those obtained for trioctahedral vermiculites. It is suggested that the minerals studied are dioctahedral forms, which have resulted from the weathering of muscovite-type micas.
Effect of Exchangeable Cation on X-Ray Diffraction Patterns and Thermal Behavior of a Montmorillonite Clay
Authors: Mielenz Richard C. , Schieltz N. Cyril , King Myrle E. 
Published: August 2006

AbstractA stratum of bentonite in the North Park (?) formation near Granby, Colorado, is composed largely of a dioctahedral Ca-montmorillonite whose formula is calculated to be $\left( {A{l_{2.84}}F{e_{0.50}}M{g_{0.72}}M{n_{0.04}}} \right)\left( {\mathop {A{l_{0.40}}S{i_{7.60}}}\limits^{\mathop \uparrow \limits^{{X_{0.86}}} } } \right){O_{20}}{\left( {OH} \right)_4}.$Na+, K+, Li+, H+, NH4+, Ca++, and Mg++ modifications were stored at 52 percent relative humidity and at 105° C-110° C. Results of X-ray diffraction, differential thermal, and thermal balance analysis depend upon the exchangeable cation and prior treatment. As with many montmorillonoids, d(001) = 22.7−30.1 Å under room conditions; ao = 5.20 Å and b0= 9.00 Å. The (001 ) interference indicates that the unit cell typically includes two packets, or possibly more, which may be derived geometrically from each other by a glide of 1.73 Å along (110) and 180° rotation. Weight loss above 190° C-3670 C exceeds that indicated by the Hofmann structure but conforms reasonably with loss indicated by a structure after that proposed by Edelman. Inverted Si-O tetrahedra are presumed to equal the number of univalent cationsIt is suggested that the exchangeable cations form hydroxides during thermal analysis by reaction with (OH)− at the apex of inverted Si-0 tetrahedra. The resulting H2O and NH4OH are lost during thermal analysis, thus explaining excessive weight loss. Ca (OH)2 and Mg(OH)2 so produced release one mole of H2O during thermal analysis. KOH, NaOH, and LiOH are not decomposed below 1,000° C.Thermal products vary with exchangeable cation and crystallinity increases with prior drying. The Li+ and Ca++ modifications produce beta-quartz and alpha-cristobalite with spinel and glass, whereas the other modifications produce only spinel and glass.
Variations in Viscosity of Clay-Water Suspensions of Georgia Kaolins
Authors: Woodward LeRoy A. 
Published: August 2006

AbstractThe viscosity of clay-water suspensions is an important factor in determining commercial uses of Georgia Kaolins. Impurities, such as montmorillonite type minerals, in these basically kaolinite clays play a part in causing variations in viscosity. However, seemingly pure kaolinite clays also show variations which seem to be related to morphology and degree of crystallinity. Studies are underway to determine the various factors involved.
Interstratified Layer Silicates in Some Soils of Northern Wisconsin
Authors: Whittig L. D. , Jackson M. L. 
Published: August 2006

AbstractExamination of the silt and clay fractions of two northern Wisconsin soils, Omega loamy sand of the Brown Podzolic group and Ahmeek loam of the Brown Forest group, revealed considerable quantities of interstratified layer silicates. The two soils contained montmorin, vermiculite, chlorite, and illite both as discrete and interstratified components. Regularly alternating montmorin-illite structures, which registered a 28 Å first order diffraction peak, and vermiculite-illite structures, which yielded a 24 Å first order peak, were observed in the fine silt fractions of the Ahmeek loam A3 and B22 horizons, respectively. Weak diffraction peaks in general and lack of binary mixture average spacings was suggestive of ternary or quarternary interstratification of illite, chlorite, vermiculite, and montmorin in the medium and fine clay fractions of the Ahmeek loam horizons. Randomly interstratified vermiculite-chlorite and vermiculite-montmorin, as revealed by comparative basal diffraction peaks before and after heating potassium saturated samples, were evidenced in the fine silt and clay fractions of the Omega profile.Mixed layer components in the Omega and Ahmeek soils originated from illite and chlorite in the? horizons with a progressive increase in proportions of first vermiculite and finally montmorin with proximity to the soil surface. The observed weathering transitions within the mixed layer structures illustrates the effects of accelerated leaching which has taken place in these coarse textured soil profiles, even though these soils are relatively young (late Pleistocene).
Relation of Porosity and Permeability to the Origin of Diaspore Clay
Authors: Allen Victor T. 
Published: August 2006

AbstractThe apparent porosity of flint, boehmite and diaspore clays bears no direct, consistent relation to the permeability of the same type of clay or to the alumina content of each type. The coefficient of permeability varies with the type and the structure of each flint clay. Diaspore clays have high permeability compared to flint clays, and the boehmite clays measured generally have a permeability intermediate between that of diaspore and that of flint clays. The apparent increase in permeability with increase in alumina content suggests that permeability has increased as silica was removed from flint clay to form boehmite and diaspore clays.A vertical pipe of diaspore clay 1½ inches in diameter was collected by Fred Mertens of the Laclede Christy Company at the Shockley-Thompson diaspore pit at Belle, Missouri. The pipe contains 69.16 percent alumina compared with 55.30 percent alumina for the average of the walls a few inches from the pipe. Diaspore in the pipe has vertical banding indicating it was deposited along a vertical crack. The formation of cracks in brittle flint clay is an important process in increasing the permeability and providing openings along which ground water can migrate.A restudy of boehmite and diaspore clays emphasizes not only a replacement of the colloform and oolitic structures of flint clays by diaspore and boehmite, a gradual alteration of flint clay to diaspore clay along fractures, and second-generation diaspore cutting early diaspore, but also the importance of secondary processes in the origin of diaspore and boehmite clays.
Quantitative Evaluation of the Kaolinite and Illite in Underclays
Authors: Schultz Leonard G. 
Published: August 2006

AbstractOriented slides of twelve different mixtures of kaolinitic and illitic underclays were studied with the X-ray spectrometer and the resulting curves were evaluated on the basis of the area of the 001 peaks. Although the areas from the unmixed components varied greatly, within any given mixture the two clays were quantitatively comparable on the basis of a 1/1 001 peak area ratio. The considerable peak area variations from slide to slide are the result of different degrees of preferred orientation and are not due to any appreciable differences in crystallinity. Mixed-layering of expandable material with the illitic component does not affect the quantitative comparisons significantly.
The Colloid Science of Important Clay Minerals
Authors: Hauser Ernst A. 
Published: August 2006

A few days after Dr. RudoIf Wegscheider of the University of Vienna celebrated his sixtieth birthday in October, 1919, he began his next class with the following words:
“Today I intend to start discussing with you the physico- and colloidchemistry of the element silicon. It is not only the most abundant of an the nonmetallic solid elements which occur on this earth, but it is also, in combination with other elements, by far the most widely distributed one, with the exception of oxygen. Its only real competitor in this respect is the element carbon. Carbon differs from silicon above all by its property of combining with itself, thereby forming a great variety of compounds. With our increasing knowledge of the chemical composition of these carbon compounds the foundation for organic chemistry was laid. Science is never at a standstill, however. I refer here to physico-chemistry and to the even more recent addition to the specialized branches of chemistry, colloid chemistry.“I probably will not live to witness the importance that the colloid chemistry of siliceous matter will play in the not too distant future. In my opinion the physico- and colloid-chemistry of matter containing silicon as its maj or component will become a serious competitor to organic chemistry.”
Forces and Adsorption at Solid Surfaces
Authors: McMillan W. G. 
Published: August 2006

AbstractEssentially all interactions between atoms, molecules and ions spring from the electrical charges borne by the nuclei and electrons of which they are constituted. Two broad classes of interaction are distinguished by the terms “chemical” and “physical,” the former referring to those cases wherein some of the electrons of the two participants have become shared, with the consequent formation of a chemical bond. Such chemical forces have the property of saturation, are of very short range, and are usually associated with the comparatively large binding energies of a few electron volts. Some of the more important types of physical interactions, listed more or less in order of decreasing energy, are: ion-ion, ion-dipole, dipole-dipole, ion-induced dipole, induced dipole-induced dipole, etc. Those not involving ions are often grouped together under the term “van der Waals forces,” and generally have energies of only a fraction of an electron volt. The (long-range) ion-ion interactions (“ionic bonds”) are mainly responsible for the stability of ionic crystals, and thus may have energies comparable with those of chemical bonds.An adsorbed molecule interacts very nearly additively with all the constituent atoms and ions of the adsorbent surface, and with other adsorbed molecules as well. The collective effect may be described through the “energy of adsorption,” which will generally be a function of the amount adsorbed. In physical adsorption, multilayer films and capillary condensation may occur at gas pressures approaching saturation.The small size and high dipole moment of the water molecule make it strongly adsorbed on ionic substrates. The lamilar structure of the clay minerals furnishes enormous surface areas for adsorption. Investigation of these interactions at the molecular level provides a fundamental basis for a more complete understanding of clay-water systems.
Synthesis of Clay Minerals at Low Temperatures
Authors: Henin S. 
Published: August 2006

AbstractNumerous attempts have shown that it seems to be impossible to crystallize co-precipitates of silica and hydroxides; we therefore attempted to prepare clay minerals starting from solutions of their constituents. By allowing these dilute solutions (tenths of milligrams per liter) to pass slowly into a flask containing distilled water, it has been possible to prepare substances similar to clay minerals. These have been identified by x-rays, chemical analysis, dehydration curves, and electron micrographs.Using as cations Mg, Fe2+, Fe3+, and Ni, minerals of the montmorillonite type have been prepared for various pH values (generally greater than 7). Below this, value, depending on the cations; oxides, hydroxides, or amorphous materials are obtained.Under certain conditions in the absence of silica the glass vessel was attacked, and anti-gorites of Mg and Ni were then obtained. Always when the supply of silica was small, and with the cation introduced in the form of a very dilute solution, the process gave rise to montmorillonite. In the presence of K, illites were sometimes formed.The method seems to be of very general application. Only the purely aluminum minerals offer difficulties of preparation. The significance of these results is discussed.
The Structure and Morphology of a Kaolin Clay from Les Eyzies (France)
Authors: Brindley G. W. , Comer J. J. 
Published: August 2006

AbstractIt is shown by x-ray analysis and electron micrographs that the clay from Les Eyzies is composed of about equal amounts of platy material (kaolinite), and rolled or tubular material (halioysite). Detailed examination of the electron micrographs shows oriented tubes or rolled sheets which may have originated from well-aligned platy material which has fractured and subsequently curled into rolled forms. Hexagonal features on the surfaces of the rolled forms are described. The laboratory results are correlated with geological data on the formation of the clay.
Contribution to the Study of Sepiolite: II. Some Considerations Regarding the Mineralogical Formula
Authors: Martin-Vivaldi J. L. , Cano-Ruiz J. 
Published: August 2006

AbstractIt is suggested that the minerals of the palygorskite-sepiolite group occupy the region of discontinuity between dioctahedral and trioctahedral minerals. There is thus a series of minerals, the two extremes having a planar lattice, and the intermediate members a fibrous lattice. The lamellar-fibrous change in structure takes place as the number of vacancies increases progressively.Among the minerals of fibrous structure, the structural change from sepiolite to atta-pulgite occurs in such a way as to allow no more than one vacancy per structural fiber, and per half cell, as if this vacancy were not distributed at random, but symmetrically among the octahedral positions. The greater the number of vacant octahedral positions, the smaller the extension of the octahedral layer. The margin of variation in the number of vacant octahedral positions per structural fiber is greater in sepiolite than in attapulgite, probably because of the greater width of the fiber in the former mineral.
Contribution to the Study of Sepiolite: III. The Dehydration Process and the Types of Water Molecules
Authors: Martin-Vivaldi J. L. , Cano-Ruiz J. 
Published: August 2006

AbstractA detailed study has been made of the dehydration of sepiolite. This work, together with other studies of dehydration in vacuo and over phosphoric anhydride, rehydration of samples heated to various temperatures, specific surface, water uptake, and x-ray examination of natural and heated samples (to be published later), lead us to certain conclusions regarding types of water in sepiolite. A comparison is made with attapulgite.
Forces Between Suspended Bentonite Particles
Authors: van Olphen H. 
Published: August 2006

AbstractPurified sodium bentonite suspensions in water display rigidity at concentrations as low as about 2 percent. On addition of NaCl the yield stress decreases, but beyond about 5 meq/ liter of NaCl it increases. The same is true for the relative viscosities and the sediment volumes of more dilute suspensions. This is interpreted as a flocculation-deflocculation-floccu-lation sequence. The paradoxical phenomenon of flocculation of the clean suspensions is explained by the concept of positive edge charge of the clay plates, allowing positive edge to negative flat-surface flocculation.Both the purified and the salt-flocculated gels show Bingham flow behavior. When Good-eve’s analysis of Bingham flow is applied, the linking force between the clay plates in the pure gels is computed at about 10−4 dyne.The salt-flocculated gels show thixotropic hysteresis, whereas the pure gels set immediately after stirring. This means that there is no energy barrier for gelation in the pure gels, which is in line with the proposed mechanism of association due to Coulomb attraction. In the salt-flocculated gels there must be an energy barrier causing thixotropic hysteresis. This might be expected from the summation of residual double-layer repulsion and van der Waals attraction. Considering thixotropic stiffening as slow coagulation, the height of the energy barrier could be calculated from the thixotropic increase of the modulus of elasticity with time after previous shear breakdown of the structure. The reasonable value of 7 kT was found for the height of the energy barrier of a gel containing 30 meq/liter of NaCl.