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Showing 1 to 20 of 84 for “"Smectite"”.
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Chemical modification of smectite clays
Today, speciality use organoclays are being developed for an increasingly large number of specific applications. Many of these, including use in cosmetics, polishes, greases and paints, require that the material be free from abrasive impurities so that the product retains a smooth `feel'. The …
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Interlamellar modification of smectite clays
… synthetic, have a wide range of applications. Smectite clays are not true insulators, their slight conductivity has been utilized by the paper industry in the development of mildly conducting paper. In particular, the synthetic hectorite clay, laponite, is employed to produce paper which is …
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Sorption mechanisms of dibenzo-p-dioxin/furan from water by smectite clays and theoretical studies on formation pathways of chlorodibenzo-p-dioxins from precursor chlorophenols on smectite clays
… deposits. Sorption experiments demonstrated that smectites, especially Cs-saponite, effectively adsorbed dibenzo-p-dioxin /furan from water. Adsorption was promoted by exchangeable cations with low hydration energies, and negative charge in the smectite arising from the tetrahedral siloxane …
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Steric Effects of Alkyl Ammonium Salts on the Combustion of Exchanged Smectite Clays
… the cation exchange capacity (CEC) of clays. Smectite clays were modified with several alkyl ammonium salts varying in number of carbons and the spatial orientation of the carbons about the central nitrogen atom. The clays used, standards purchased from the Source Clay Repository, have CECs of …
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Smectite to illite transformation of Gulf of Mexico -Eugene Island (GoM-EI) mudrock
… aims to look at the relationship between smectite-to-illite transformation and overpressure generation. The proposed research has two phases. Phase one objective is to study the reaction rate and the conditions such as temperature, time, KCl concentration that induce smectite-to-illite …
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Smectite/Illite Distribution and Diagenesis in the South Timbalier Area, Northern Gulf of Mexico
… determined by XRD, is primarily mixed-layer smectite and illite with a minor amount of kaolinite. The mixed-layer mineralogies are end-member smectite, mixed-layer smectite, mixed-layer illite, and end-member illite. These clay mineral fractions do not correlate with age. The illite mixed …
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The Effect of Smectite Layer Thickness and Fabric Upon Salt Filtration at Room Temperature
A solution 0.79 Molal in NaCl and 0.079 Molal in CaCl(,2) was forced through clay cakes made by sedimenting the one-half to two micron size fraction of Cheto clay. The two cakes sedimented from distilled water had nearly parallel-flake fabric whereas the two sedimented from the described brine …
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Argillic Alteration Associated With the Amethyst Vein System, Creede Mining District, Colorado (Illite, Smectite)
The Amethyst Vein System is an epithermal Ag-Pb-Zn-Cu-Au deposit in the Creede mining district, southwest Colorado. Silicification and argillization are the two dominant facies of hydrothermal alteration associated with the deposit. Most silicification occurs in the intermediate and deep levels of …
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Experimental Determination of Smectite Hydration States Under Simulated Diagenetic Conditions (high-Temperature, X-Ray Diffraction, Dehydration)
The hydration states of a dioctahedral smectite in contact with saline solutions were determined at temperatures and hydraulic pressures that simulate burial diagenetic environments. A high-pressure high-temperature X-ray cell, mounted on an automated General Electric XRD3 X-ray diffractometer, was …
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Effects of structural iron oxidation state on the hydraulic conductivity and potassium fixation of smectite clays and soils
Restricted to the U of I community indefinitely during batch ingest of legacy ETDs
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Electrokinetic and Chemical Aspects of Transport of Chloride Brines Through Compacted Smectite Layers at Elevated Pressures (Electroosmosis, Streaming, Conductivity)
Solutions of NaCl and NaCl-CaCl were forced through clay plugs made by compacting the 0.2 to 2.0 micron size fraction of Cheto montmorillonite. The concentration of NaCl solution was either 1.10 m or 1.087 m, and that of NaCl-CaCl(,2) solution was 0.92 m in NaCl and 0.075 m in CaCl(,2). Clay plug …
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Sediment-water interactions in three Holocene saline, alkaline playas, south-central Oregon: Mineralogy and geochemistry
… in south-central Oregon. Al-rich dioctahedral smectite dominates outcrop samples from the Alkali and Abert basins, whereas Al- and Fe-rich dioctahedral smectite is most abundant in the Alvord basin. The composition of smectite from outcrop samples reflects the composition of parent rock in each …
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The Effects of Iron Oxidation State on Surface Chemistry and Structure of Iron-Bearing Smectites: Cation Fixation and Selectivity, Structural Iron Environment, and Dissolution
Smectites are widespread as a major constituent of soils and sediments and include a substantial amount of structural Fe. The reduction of structural Fe(III) invokes partial dehydroxylation, protonation, and site translocation of Fe(II) to alter the crystal structure. The structural changes, …
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The Twiggs Clay: mineralogy, origin, and industrial properties of an upper Eocene opaline claystone in the coastal plain province of Georgia, U.S.
… composed predominantly of disordered silica and smectite. The smectite is dioctahedral, and the X-ray diffraction signature of the opaline phase is most like that of tridymite. The uppermost stratum is composed of kaolinite and smectite. This stratum lies above a prominent erosional surface and …
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Origin and Diagenesis of Lacustrine Sediments of the Late Oligocene Creede Formation, Southwestern Colorado
… The abundance of clinoptilolite - Al-smectite in drillcore CCM-2 is consistent with diagenetic waters having low to moderate salinity and a pH of 7-9. The higher-grade mineral assemblage (analcime, K-feldspar, quartz, interstratified illite/smectite and chlorite/smectite in CCM-1) is …
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Quantifying Properties and Variability of Expansive Soils in Selected Map Units
… the ESI, the greater the shrink-swell potential. Smectite distributions within the soil profiles were investigated. Smectite concentration in the clay fraction increases with depth in soils formed from diabase and thermally altered shale. Smectite weathers to kaolinite and hydroxy-interlayered …
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Ion Filtration and Stable Oxygen Isotopic Fractionation Resulting From the Passage of Sodium-Calcium-Chloride Brine Through Compacted Smectite Layers at Elevated Temperatures and Pressures
A solution 5.00 molal in NaCl and 0.45 molal in CaCl(,2) was forced through 1.5 cm-thick clay plugs made of sedimented, randomly-oriented one-half to two micron diameter montmorillonite flakes. Two sets of experiments were carried out. In one set the confining pressure on the clay was 5000 pounds …
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Physical chemistry of microbially-reduced smectites
The ability of bacteria to reduce smectite structural Fe and the effect microbial reduction has on clay swelling, flow behavior, and the crystal structure was studied to better understand the reduction process. Structural Fe reduction by combinations of Pseudomonas bacteria is a diffusion driven …
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Compression behavior of smectitic vs. illitic mudrocks
… the possible mechanisms for overpressure is the smectite-to-illite (S-I) transformation. During the transformation, the basal spacing of the smectite layer reduces. The interlayer water is released into pore space, causing an increase in pore pressure. This thesis investigates the compression and …
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Potassium Metasomatism and Diffusion in Cretaceous K-Bentonites From the Disturbed Belt, Northwestern Montana and in the Middle Devonian Tioga K-Bentonite, Eastern u.s.a. (Illite/smectite, Clays, Diagenesis, United States)
This thesis presents X-ray diffraction, elemental, K/Ar, and petrographic data of K-bentonites and enclosing shales from the Marias River Formation (Late Cretaceous) in the disturbed belt of Montana. The objective of this study is to determine the kind and extent of chemical exchange between …
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