Vermiculite

About: Vermiculite is a research topic. Over the lifetime, 2320 publications have been published within this topic receiving 37142 citations.

Biotite Weathering in Granites of Western France

Abstract: Electron microprobe analyses of fresh biotites, altered biotites and newly formed vermiculitic phases formed in two weathering profiles of the same calcalkaline granite indicate that the composition of the altering fluid can greatly influence the composition of the newly formed minerals. In one profile, calcic carbonate solutions produce a regularly interstratified mineral (hydrobiotite) which concentrates Fe and Si relative to Al and Mg while another profile gives a vermiculite-intergrade mineral with a higher Al content. Hydrobiotite (interstratified mineral) persists into later stages of weathering than does vermiculite in these profiles. In both cases the final assemblage is kaolinite + oxides which also begins to form in the early stages of weathering. Biotite breaks down to a multiphase assemblage in both of the profiles.

Production of clay derivative having porous structure

Abstract: PURPOSE: To produce the titled derivative having large layer-to-layer spacing and specific surface and which is extremely stable and useful to pigments, adsorbents, catalysts (carrier), heat insulators, etc., by allowing a Ti salt soluble in water and acids and/or a titania sol to react with swelling phyllosilicate. CONSTITUTION: A Ti salt soluble in water and acids and/or a titania sol (e.g., TiCl 4 , TiOSO 4 , etc., and their salts) are allowed to react with swelling phyllosilicate (e.g., smectite, vermiculite, synthetic mica, etc.) to produce a clay derivative having porous structure. Since the clay derivative thus produced has large layer-to-layer spacing of 25W63Å and a large specific surface of 300W470m 2 /g and is highly stable, the derivative can be extensively used as pigments, encapsulating agents, adsorbents, catalysts, catalyst carriers, and heat insulators. COPYRIGHT: (C)1987,JPO&Japio

Vermiculite’s strong buffer capacity renders it unsuitable for studies of acidity on soybean (Glycine max L.) nodulation and growth

Abstract: Background Vermiculite is the most common soil-free growing substrate used for plants in horticultural and scientific studies due to its high water holding capacity. However, some studies are not suitable to be conducted in it. The described experiments aimed to test the suitability of vermiculite to study the effect of acidity on nodulation and growth of soybean (Glycine max L.).

Interstratified Layer Silicates in Some Soils of Northern Wisconsin

Abstract: Examination 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 A first order diffraction peak, and vermiculite-illite structures, which yielded a 24 A 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).