bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Formation of Chlorite-Like Structures from Montmorillonite
Authors: Slaughter M. , Milne I. H. 
Published: August 2006

AbstractChlorite-like complexes of montmorillonite with magnesium hydroxide or aluminum hydroxide have been prepared under a variety of physical and chemical conditions. Requirements for the preparation of these complexes have been simplified considerably by the use of rapid mixing techniques. A complex may be formed either by precipitating the hydroxide in a clay suspension or by preparing the precipitate separately and mixing it immediately with the clay suspension. It is suggested that the process involves the adsorption of a layer of the precipitate over the entire surface of the montmorillonite unit layer rather than the direct formation of a structure in the interlayer space. It is considered that there is no appreciable permanent association of unit 10 Å layers of montmorillonite in a well stirred suspension, even in the presence of strong salt solution, but that instead most clay surfaces are exposed continually. The chlorite-like structure develops only upon association of the unit layers through aging or dehydration.The aluminum hydroxide complex with montmorillonite differs somewhat from the magnesium type, but it has the approximate chlorite basal spacing. The complex shows a second-order basal diffraction spacing of low intensity, and forms regular expanded structures with water or ethylene glycol. A gibbsite structure for the interlayer material is most compatible with the x-ray data.The occurrence of this process in sediments and soils is considered to be very probable, although it is premature to consider precise environments until more experimental data are available.
Geochemical Method for Determining Paleosalinity
Authors: Frederickson A. F. , Reynolds R. C. 
Published: August 2006

AbstractThe boron content of sea water increases linearly with salinity within the range tested. The boron content of the illite minerals in the clay mineral size fraction of many types of sedimentary rocks has been shown to increase with the “geologically known” salinity prevailing during deposition of the rocks. It is believed that boron is abstracted by the illitic clay minerals from sea water in proportion to the salinity of the sea water. This boron content is not substantially changed by other geological processes normally operative in sedimentary rocks. It is concluded that the boron content of illite minerals in sedimentary rocks can be used to evaluate the salinity of the sea prevailing at the time the sediment was deposited.
Clay Mineral Alteration in Some Indiana Soils
Authors: Droste John B. , Bhattacharya N. , Sunderman Jack A. 
Published: August 2006

AbstractX-ray analyses of samples from thirteen soil profiles that were formed on glacial till, loess, and Mississippian limestones of Indiana indicate that (1) in some soil profiles chlorite of the parent material is changed completely to montmorillonite with intermediate stages of random mixed layers of chlorite-vermiculite-montmorillonite; (2) some of the illite of the parent material produces montmorillonite through random mixed layering of illite-montmorillonite, but the illite is not entirely altered in any profile; and (3) kaolinite may be produced as a weathering product, or it may remain unchanged from the parent material.
Some Conditions Affecting the Adsorption of Quinoline by Clay Minerals in Aqueous Suspensions
Authors: Doehler R. W. , Young W. A. 
Published: August 2006

AbstractThe adsorption of quinoline by Na+- and Ca2+-montmorillonite, illite, and kaolinite in water suspensions was studied for varying physico-chemical conditions. The shapes of the adsorption isotherms depended upon these imposed environmental conditions, which were quinoline concentration, pH, salinity, time, and temperature.In order to be in the range of concentrations of organic materials in natural waters, these studies covered the concentration range, from 0 to several hundred ppm. Of the variables studied, pH was critical. Throughout the pH range 8.5–6.0, adsorption increased as pH decreased. The change in adsorption as salinity increased depended on pH, clay mineral, and quinoline concentration. In our experiments, samples reached equilibrium within 2–3 hr, and moderate temperature changes made little difference in adsorption amounts.Under the same conditions, Na+-montmorillonite adsorbed the most quinoline, kaolinite the least, and Ca2+-montmorillonite and illite intermediate amounts.Two mechanisms seem to control this adsorption: ion exchange and molecular adsorption. This paper attempts to explain the effects of the physico-chemical environment on adsorption by these two mechanisms.
Interpretation of the Composition of Vermiculites and Hydrobiotites
Authors: Foster Margaret D. 
Published: August 2006

AbstractFormulas calculated from modern analyses of vermiculites and hydrobiotites show that these minerals resemble phlogopites and magnesian biotites in tetrahedral and octahedral layer composition, but usually have a higher proportion of trivalent octahedral cations. None of the formulas studied resembles those of ferroan biotites in composition.In a few formulas the negative layer unit charge and the neutralizing positive interlayer charge are as high as those found in phlogopite; about 1.00 in the half-cell formula, but in most vermiculite formulas the charge on the layer unit and the interlayer charge are considerably lower than in phlogopite. Such a decrease in the amount of these charges may be due to oxidation of Fe2+ to Fe3+, which would increase the positive octahedral charge, and, consequently, decrease the layer unit charge. Oxidation of Fe2+ to Fe3+ also explains the higher proportion of trivalent octahedral cations in vermiculites and hydrobiotites.Few papers furnish both cation exchange data and analyses of the samples studied; consequently it is difficult to correlate interlayer charge and cation exchange capacity, but empirically the interlayer charge multiplied by 200 yields a value that approximates the cation exchange capacity, provided the Mg has been allotted correctly between octahedral and interlayer positions.On the basis of composition and charge relations, vermiculites may be interpreted as formed from phlogopites or magnesian biotites by replacement of K by Mg.
Industrial Applications of Kaolin
Authors: Murray Haydn H. 
Published: August 2006

AbstractKaolins are used in a multiplicity of industries because of unique physical and chemical properties. Shape, particle size, color, softness, and non-abrasiveness are physical properties that are especially important. Chemical properties, such as comparatively low base exchange capacity, as well as other chemical properties of the kaolin surface, and relative insolubility, are governing in many uses. In 1960, well over 2,000,000 tons of kaolin was used in the United States, more than one-half of which was consumed by the paper industry. The relationships between physical and chemical properties are discussed in the application of kaolin to paper, rubber, ceramics, plastics, ink, catalysis, insecticides, and numerous other uses. A few new uses of kaolin are discussed along with a short gaze into a crystal ball to see what the future may hold for that useful mineral, kaolin.
Sepiolite and Related Compounds: Its Stability and Application
Authors: Preisinger Anton 
Published: August 2006

AbstractThe unit-cell characteristics and structures of sepiolite, ferri-sepiolites (xylotile, mountain wood, gunnbjarnite), loughlinite and palygorskite (attapulgite) and their structural relationships are discussed. The chemical, morphological and thermal properties are explained by their structures. The unit-cell characteristics and structures of sepiolite “anhydride”, loughlinite “anhydride” and palygorskite “anhydride” are given. Under low water vapor pressure the phase transformations sepiolite to sepiolite “anhydride” and palygorskite to palygorskite “anhydride” are reversible. It was not possible to synthesize sepiolite in the system MgO−SiO2−H2O under confined pressure within a range of 80° to 300°CThe possibility of the application of sepiolite and related compounds in industry, specially in the automobile industry, is referred to.
Studies in Position and Mobility of the H Atoms in Hydrous Micas
Authors: Rosenqvist I. Th. 
Published: August 2006

AbstractThe hydrogen content of dioctahedral and trioctahedral micas has been investigated by means of infrared spectroscopy and radioactivo measurements. Dioctahedral and trioctahedral micas have been treated with deuterium oxide and tritium-bearing water. The introduced isotopes of hydrogen have been determined after various thermal treatments.It is concluded that dioctahedral hydrous micas may represent mixed crystals between K(Si3Al)Al2O10(OH)2 and H2O(Si3Al)Al2O9(OH)3, whereas trioctahedral micas seem to represent mixed layer minerals between phlogopite and vermiculite.
Cell Dimension Studies on Layer-Lattice Silicates: A Summary
Authors: Radoslovich E. W. 
Published: August 2006

AbstractThe statistical techniques of multiple regression analysis have been used to obtain more reliable formulae relating the cell dimensions especially the b-axis) of layer-lattice silicates to their composition or structural formulae. This allowed the significance of each coefficient to be expressed precisely and so provided rigorous tests for certain structural concepts about the different factors affecting cell dimensions. More recently an explicit theory has been developed about the various forces controlling the layer-lattice silicate structures which (a) removes some anomalies, (b) explains many variations in accurate bond lengths and angles, and (c) has several interesting structural implications for properties such as polymorphism, composition limits, crystal morphology, and stability under weathering. This paper summarizes work now being published in extenso elsewhere.
Argillic Alteration and Uranium Emplacement on the Colorado Plateau
Authors: Kerr Paul F. , Jacobs Marian B. 
Published: August 2006

AbstractArgillic alteration is recognized in association with uranium deposits on the Colorado Plateau and along border areas. Alteration and mineralization are geometrically related in sedimentary strata where solution conduits result from lithologic and structural changes. The association also exists in collapse features and in breccia pipes. Occasional diatremes bearing uranium point to hypogene solution activity following igneous invasion as one original source for uranium ions. In several places ascending fluids apparently were confined under sufficient pressure to blast consolidated strata into vertical chimneys of brecciated masses. Pipes and fracture systems which transect porous strata provide paths along which hypogene solutions may ascend from depth and migrate horizontally. Alteration may extend both vertically and horizontally, encircling such areas.Occasionally silica or carbonate precipitation accompanies uranium. Where found, well-marked masses of carbonate or silica replace sedimentary strata. Field conditions demonstrate upward migration of solutions. Often silica and carbonate may be dissolved from country rock and redeposited at higher levels. The silica minerals involved are quartz, chalcedony, and opal; the carbonates, calcite, dolomite and siderite.The identification of mica polymorphs close to ore, corresponding to those created at elevated temperatures in the laboratory; the recognition of dickite in gouge zone veinlets associated with primary sulphides; uranorganic complexes; and replacement textures involving multiple pseudomorphs after a single mineral, further indicate alteration by hypogene solution.Uranium deposition is favored by precipitating agents peculiar to certain strata. Hydrogen sulphide, produced by decaying fossil plant detritus, or petroliferous material, appears to have been an effective precipitating agent. Strata often involved are members of the Chinle or Morrison Formations. These units provide an environment with sustained reducing conditions favorable for uranium precipitation. The reduction of hexavalent uranium in solution occurs to the less soluble tetravalent form. Accompanying bleaching of red beds also suggests reducing conditions.
The Nature of Illite
Authors: Gaudette H. E. , Eades J. L. , Grim R. E. 
Published: August 2006

Abstract
Chemical composition, X-ray diffraction and other
analytical data of a series of samples of clays that are composed
essentially of illite are presented. The physical properties of these
samples are given and related to variations in the composition and character
of the illites.
Data indicate that these illites have less potassium than
well-crystallized micas and some of them are not essentially mixed-layer
structures, It is concluded, therefore, that illite is not necessarily a
mixed-layer material.
Expansion of Potassium-Depleted Muscovite
Authors: Scott A. D. , Reed M. G. 
Published: August 2006

Abstract
Muscovite samples were K-depleted with NaCl-NaTPB
solutions. By varying the extraction period, samples that varied in total K
from 219 to 15 meq per 100 g. were prepared. This treatment did not change
the layer charge in the mineral, but it did increase the basal spacing of
the mineral from 10 to 12.3 Å.
The changes in basal spacing that occurred when increasing amounts of
interlayer K were replaced by Na and the effects of subsequent treatments
for the removal of KTPB were determined with two size fractions. In each
case, the interlayer K at the periphery of the muscovite particles was
replaced by Na, and a fringe of K-depleted mineral with a basal spacing of
12.3 Å developed. In a <50µ sample the particles retained an inner core
of 10 Å mineral as the weathered fringe increased. There was no evidence of
interstratification. With this sample there was considerable Na trapping
when the KTPB was removed with NH4Cl-acetone-water
solutions. On the other hand, with a <2µ
sample, mixed-layer structures developed as K was removed, and less Na
trapping occurred. Na trapping was reduced by removing the KTPB with boiling
NH4Cl.
Undried Na-degraded muscovite with only 15 meq K per 100 g did not
expand beyond 12.3 Å. The NH4-degraded muscovite
samples had a basal spacing of 10.4 Å.
Discussions and Recommendations Concerning the Nomenclature of Clay Minerals and Related Phyllosilicates
Authors: Brindley G. W. 
Published: August 2006

AbstractAttempts to find a generally acceptable scheme of classification and nomenclature for clay minerals by the nomenclature committees of The Clay Minerals Society (C.M.S.), the Comité International pour l’Étude des Argiles (C.I.P.E.A.), and the International Mineralogical Association (I.M.A.) are summarized. The C.M.S. committee has been working on this problem continuously since 1961 and has transmitted its views to C.I.P.E.A., first at the time of the Stockholm meeting, 1963, and subsequently, in more detail, after receiving the first draft of the C.I.P.E.A. proposals. The C.I.P.E.A. committee held discussions in Stockholm, 1963, and subsequently submitted a first draft to 32 nations; from the replies received, a final draft of the C.I.P.E.A. proposals was prepared and submitted to the I.M.A. in 1964. The report from the I.M.A. was made available in August, 1965.
Quantitative Clay Mineralogical Analysis of Soils and Sediments
Authors: Alexiades C. A. , Jackson M. L. 
Published: August 2006

AbstractThe objective of this paper is to present flow sheets for a system of quantitative minera-logical analysis of clays of soils and sediments and to show representative results. Selective dissolution analysis by the Na2S2O7-HCl-NaOH procedure yields the quartz and feldspar contents (0 to 63%) and differentiates feldspar K from mica K. The NaOH-thermal system of selective dissolution yields the allophane plus gibbsite, kaolinite plus halloysite, and dickite contents (0 to 84% for the sediments; 1 to 25% for soil clays) Mica contents (0 to 92% for the rock specimens, 7 to 43% for soil clays) are determined by nonfeldspathic K (and Na). Vermiculite contents (1 to 97% of specimens; 3 to 21% for soil clays) are measured by blocking of interlayer CEC by drying at 110°C while K saturated and replacing with NH4Cl. Montmorillonite (and palygorskite) contents (0 to 85% of specimens; 3 to 36% of soil clays) are determined by the CEC not blocked by the K and NH4 sequence for vermiculite. Chlorite contents (0 to 85% for specimens; 0 to 37% for soil clays) are determined by thermal gravimetric analysis, after allocation of OH water lost between 300 and 950°C to other hydrous minerals determined.The best evidence of the accuracy of the system of analysis lies in the consistent total recovery of 24 standard mineral samples averaging 100.4 ± 1.3 (± standard error of means) and of 22 soil clay samples averaging 99.5 ± 0.8. The different constituents were present in widely different proportions in the various samples, and were determined by independent methods. The complementary total of near 100% (maximum range 95 to 105% for specimens; 95 to 103% for soil clays) for the analyses is a significant measure of the specificity of the several determinations.
Kinetics of Reactions in the Conversion of Na- or Ca-Saturated Clay to H-Al Clay
Authors: Basin Amos , Ravikovitch S. 
Published: August 2006

AbstractH-ion was added to Na or Ca bentonite suspensions. The H-ion was added either in solution, as HCl, or adsorbed on a cation exchange resin. The variation with time of the quantities of H and Al in various phases of the system was determined.In the first stage of the reaction both exchangeable H and exchangeable Al on the clay increased rapidly. Several facts showed that the exchangeable Al was not liberated by crystal structure decomposition. It is postulated that its appearance is the result of a rapid dehydroxylation, of hydroxy Al groups located at plate edges or adsorbed on basal planes, producing water and trivalent Al ions.During the second stage of the reaction, spontaneous self-decomposition of the clay structure takes place. It was found that when the H-clay in alone in suspension or with low concentration of acid, the decomposition stops after the liberation of a limited quantity of Al. Most of this Al is adsorbed on the clay and it becomes the prevailing exchangeable ion. On the contrary, when the H-clay is aging in the presence of H-resin, a system of consecutive reactions is operating. In this system, Al liberated from the structure is transferred to the adsorbed state in the clay and from there to the resin. As a result the decomposition reaction does not stop as in the absence of the resin, but is carried further.
Kaolinite Crystallization at Room Temperature by Homogeneous Precipitation—III: Hydrolysis of Feldspars
Authors: La Iglesia A. , Martin-Vivaldi J. L. , Lopez Aguayo F. 
Published: August 2006

AbstractThe kaolinite crystallization by homogeneous precipitation with previous hydrolysis of the feldspars added has been followed by pH and potassium concentration measurements. The synthesized products were studied by X-ray powder diffraction and electron microscopy and consist of kaolinite and mica, accompanied occasionally by traces of smectite. The relative quantities of the synthesized minerals depend fundamentally on the supply rate of the alkaline ions.
High Extraction Magnetic Filtration of Kaolin Clay
Authors: Iannicelli J. 
Published: August 2006

AbstractA new magnetic separation technique combines high magnetic fields, extreme gradients, and controlled retention time to separate feebly magnetic mineral contaminants from kaolin.Extraction of pyrite, siderite, hematite, iron stained anatase, and mica by magnetic filtration of kaolin significantly upgrades brightness of many sub-marginal deposits and reduces consumption of reagents in processing.
Montmorillonite Pseudomorphs after Amphibole from Melbourne, Australia
Authors: Cole W. F. , Lancucki C. J. 
Published: August 2006

AbstractWell developed smectite “crystals” up to 10 mm long, which probably are pseudomorphic after titaniferous hornblende phenocrysts, are present in a weathered dike in a Melbourne clay pit. The pseudomorphs contain 77 per cent of montmorillonite as determined by X-ray powder diffraction, differential thermal analysis, thermo-gravimetric and chemical analysis. The pseudo-hexagonal shape of the pseuodomorphs probably reflects the original crystal habit of the hornblende. The mechanism of alteration of an amphibole to a smectite is discussed.
Cation and Silica Relationships of Mica Weathering to Vermiculite in Calcareous Harps Soil
Authors: Henderson J. H. , Doner H. E. , Weaver R. M. , Syers J. K. , Jackson M. L. 
Published: August 2006

AbstractA steady state reaction of apparent equilibrium of K mica + Ca2+ ⇄ Ca vermiculite + K+ was indicated by prolonged dissolution extractions from Blount soil clay (from northern Indiana) abundant in dioctahedral mica and vermiculite, with log Keq = 2.92 for the reaction when extrapolated to infinite time. From this and published free energies of formation of mica and kaolinite, a mineral phase stability diagram depicting the phase joins of Ca vermiculite, muscovite, and kaolinite was constructed with the solute activity functions pH-pK+, 2pH-pCa2+, and pSi(OH)4. These solute functions for 14-day reactions of calcareous (and dolomitic), poorly drained Harps soil (from central Iowa) fell near the calcite-dolomite-CO2-H2O phase join, suggesting equilibrium. These functions for Harps soil and the control minerals muscovite, biotite, and (or) vermiculite plus calcite were plotted on the mica-vermiculite stability diagram for various CO2 partial pressures. The points fell on the vermiculite-stable side of the mica-vermiculite plane at CO2 partial pressures of 0.15 and 0.20 atm (similar to soil air that would exist under frozen soil during winter and early spring; 2pH-pCa2+ ≃ 10.3). They fell on the muscovite-stable side of the muscovite-vermiculite plane at CO2 partial pressures of 0.0001 and 0.001 atm (similar to soil air under natural summer conditions; 2pH-pCa2+, 13.6 and 12.6, respectively) and therefore K+ (and 137Cs+ in rainfall) would be expected to be fixed.The 2pH-pMg2+ values determined for Harps soil at the various CO2 partial pressures plotted either in the Mg montmorillonite stability field or on the Mg-montmorillonite-kaolinite phase join, in concordance with the abundance of montmorillonite and some kaolinite in the medium and fine clay fractions. The solute values for the nearby Clarion soil (upland, noncalcareous) plotted on the montmorillonite-kaolinite join, or with higher CO2 partial pressure, in the kaolinite stability area. The Gibbs free energy of formation (△Gf0) for a dioctahedral Ca vermiculite of −1303.7 kcal per 010 was determined from the Keq. The solute functions for the Blount soil showed kaolinite to be the thermodynamically stable phase with respect to dioctahedral mica and (or) vermiculite. The 14-day solute values for the Harps and upland Clarion soils were also on the kaolinite stability side of the kaolinite-vermiculite join. The kinetics of kaolinite formation in the upper midwestern U.S.A. are apparently slow on a scale of ~ 104 years.