Infra-red Investigation of the Migration of Lithium Ions into Empty Octahedral Sites in Muscovite and Montmorillonite

Abstract

IN work on the reaction of molten salts with layer-lattice silicates, it was found that molten lithium nitrate removed a large portion of the potassium from muscovite (< 5µ) and lithium was fixed in a not readily exchangeable manner¹. It was suggested that lithium ions migrated into the vacant octahedral positions of the dioctahedral micas in a manner similar to that postulated previously by Hofmann and Klemen² and Greene-Kelly³ for lithium-saturated montmorillonite on heat treatment. X-ray diffraction measurements of the 060 spacing of muscovite treated with lithium showed no significant increase, whereas an increase might be expected in conversion of a dioctahedral composition to a trioctahedral composition. Attempts to apply the infra-red technique of Serratosa and Bradley⁴ for determination of the orientation of OH-bond axes to indicate formation of a trioctahedral composition were also unsuccessful.