Topic
Vermiculite
About: Vermiculite is a research topic. Over the lifetime, 2320 publications have been published within this topic receiving 37142 citations.
Papers published on a yearly basis
Papers
More filters
Patent•
22 Oct 1990TL;DR: In this paper, a method of decreasing the expansion temperature and improving the expansion characteristics of vermiculite ore was proposed, which involves subjecting vermiculate ore containing interlamellar cations to a potassium nitrate solution for a time interval sufficient to ion exchange interlinear cations within said ore with potassium ions.
Abstract: A method of decreasing the expansion temperature and improving the expansion characteristics of vermiculite ore comprising subjecting vermiculite ore containing interlamellar cations to a potassium nitrate solution for a time interval sufficient to ion-exchange interlamellar cations within said ore with potassium ions. Subsequent to this ion exchange the low temperature expandable vermiculite may be expanded by heating in an oven, or incorporated in an intumescent material and heat expanded in situ, or expanded by other heating means. An intumescent sheet is provided which may be used for mounting automotive catalytic converter monoliths comprising an unexpanded vermiculite produced by the method of the invention; an inorganic fibrous material; and a binder.
44 citations
TL;DR: In this paper, the analysis of 29Si MAR-NMR spectra of micas and vermiculite was carried out and the two main factors that govern the Si, Al distribution in the tetrahedral sheet of these minerals are: (i) Loewenstein's rule (avoidance of Al-O-Al linkages), and (ii) local balance of charges.
Abstract: The analysis of 29Si MAR-NMR spectra of micas and vermiculite shows that the two main factors that govern the Si, Al distribution in the tetrahedral sheet of these minerals are: (i) Loewenstein's rule (avoidance of Al-O-Al linkages), and (ii) local balance of charges. In muscovite, phlogopite and vermiculite, Al is randomly distributed in hexagonal ring sites (meta and para dispositions equally favoured), but complying with the two above restrictions. In margarite Si and Al are observed to alternate strictly, in agreement with previous X-ray diffraction analysis.
44 citations
TL;DR: In this paper, a study of the weathering of micaceous clays in some Norwegian podzols, includes semiquantitative estimates of minerals in the concentrated clay fractions which show a decrease in the amounts of illite and chlorite, and an increase in vermiculite and mixed-layer minerals upward in the profile.
Abstract: A study of the weathering of micaceous clays in some Norwegian podzols, includes semiquantitative estimates of minerals in the concentrated clay fractions which show a decrease in the amounts of illite and chlorite, and an increase in vermiculite and mixed-layer minerals upward in the profile. Illite, the dominant mineral at depth, weathers to hydrobiotite in the surface horizon of the profile. Subsequent weathering of hydrobiotite in this portion of the profile produces trioctahedral vermiculite and smectite, or inter- grade smectite-chlorite.
44 citations
TL;DR: In this paper, mixed-layer illite-vermiculite (I/V) clays of the Xuancheng red earth were investigated using X-ray diffraction, Fourier transform infrared (FTIR) spectrometer, and high-resolution transmission electron microscopy (HRTEM) methods.
44 citations
TL;DR: It was found that the abruption of the clay sheets was induced by the localization of Cs+ at the interlayer, which provides important information for predicting the environmental fate of radioactive Cs in polluted areas, and for developing methods to extract Cs from the soil and reduce radioactivity.
Abstract: Following the Fukushima Daiichi nuclear disaster in 2011, Cs radioisotopes have been dispersed over a wide area. Most of the Cs has remained on the surface of the soil because Cs+ is strongly adsorbed in the interlayer spaces of soil clays, particularly vermiculite. We have investigated the microscopic structure of an aqueous suspension of vermiculite clay over a wide length scale (1–1000 A) by small-angle X-ray scattering. We determined the effect of the adsorption behavior of Cs+ on the structural changes in the clay. It was found that the abruption of the clay sheets was induced by the localization of Cs+ at the interlayer. This work provides important information for predicting the environmental fate of radioactive Cs in polluted areas, and for developing methods to extract Cs from the soil and reduce radioactivity.
43 citations