Topic
Vermiculite
About: Vermiculite is a research topic. Over the lifetime, 2320 publications have been published within this topic receiving 37142 citations.
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TL;DR: In this article, the ability of roots to weather phlogopite as shown by the release of interlayer-K and by the concomitant vermiculitization of the mica was investigated in the rhizosphere of Italian ryegrass (Lolium multiflorum), grown for 1 to 32 d on 2 −105 μm mica as sole source of both K and Mg.
Abstract: SUMMARY
The ability of roots to weather phlogopite as shown by the release of interlayer-K and by the concomitant vermiculitization of the mica was investigated in the rhizosphere of Italian ryegrass (Lolium multiflorum), grown for 1 to 32 d on 2–105 μm mica as sole source of both K and Mg. The K-balance showed that ryegrass was able to induce a significant release of interlayer-K from phlogopite after 8 d of cropping. After 32 d, this root-induced release of K amounted to 191 g Kg−1 of total-K and contributed a major part of plant nutrition. Concurrently, the concentration of K in solution decreased markedly in the rhizosphere and X-ray diffractometry showed a strong vermiculitization of the phlogopite. The transformation of phlogopite into vermiculite was detected when the K-concentration in the rhizosphere decreased below a threshold of about 80 μmol dm−3. That suggests that the roots act by depleting the rhizosphere-K, and thus shifting the exchange equilibrium, so as to release interlayer-K and expand the interlayer space of the phyllosilicate leading to the transformation of the phlogopite into vermiculite.
225 citations
TL;DR: In this paper, the gas barrier properties of butyl rubber/vermiculite nanocomposites coatings are described and compared to gas permeability models for composites with flake-like fillers proposed by Cussler, Nielsen, Fredrickson and Bicerano.
218 citations
TL;DR: The rate and stoichiometry of biotite dissolution were studied in the pH range 2-10 using thin-film continuous flow reactors in this article, and the results showed that the dissolution rate of a given particle can reach a steady state within ten days.
214 citations
TL;DR: The extent of cadmium sorption was vermiculite>zeolite> pumice>pumice, as shown by the Langmuir and Freundlich parameters, and it was highly dependent on mineral characteristics, and the primary variable responsible for determination of Cadmium mobility in these minerals was confirmed to be pH.
206 citations
TL;DR: The amphibole-rich Vermiculite Mountain amphiboles from the Rainy Creek alkaline-ultramafic complex near Libby, Montana were collected and analyzed.
Abstract: Thirty samples of amphibole-rich rock from the largest mined vermiculite deposit in the world in the Rainy Creek alkaline-ultramafic complex near Libby, Montana, were collected and analyzed. The amphibole-rich rock is the suspected cause of an abnormally high number of asbestos-related diseases reported in the residents of Libby, and in former mine and mill workers. The amphibole-rich samples were analyzed to determine composition and morphology of both fibrous and non-fibrous amphiboles. Sampling was carried out across the accessible portions of the deposit to obtain as complete a representation of the distribution of amphibole types as possible. The range of amphibole compositions, determined from electron probe microanalysis and X-ray diffraction analysis, indicates the presence of winchite, richterite, tremolite, and magnesioriebeckite. The amphiboles from Vermiculite Mountain show nearly complete solid solution between these end-member compositions. Magnesio-arfvedsonite and edenite may also be present in low abundance. An evaluation of the textural characteristics of the amphiboles shows the material to include a complete range of morphologies from prismatic crystals to asbestiform fibers. The morphology of the majority of the material is intermediate between these two varieties. All of the amphiboles, with the possible exception of magnesioriebeckite, can occur in fibrous or asbestiform habit. The Vermiculite Mountain amphiboles, even when originally present as massive material, can produce abundant, extremely fine fibers by gentle abrasion or crushing.
204 citations