Adsorption of Hydroxy-aluminium Polymers by Muscovite and Biotite

THE wide occurrence of hydroxy-aluminium coatings on expansible phyllosilicate clays in soils and sediments has been extensively reported1,2. In view of the marked effects of hydroxy-aluminium coatings on many properties of clays, considerable efforts have been devoted to studying the process by which they are deposited on the interlayer surfaces of phyllosilicates, and to characterizing the hydroxy-aluminium interlayers formed both in nature and in the laboratory1–11. Little is known, however, about the extent of adsorption of hydroxy-aluminium polymers by the external surfaces of phyllosilicates. This article reports the adsorption of hydroxy-aluminium polymers by various size fractions of muscovite and biotite which have external surfaces only.