Synthesis and ion-exhange propertis of Na-4-mica

Abstract

The preparation of the high-charge-density sodium fluorophlogopite mica Na-4-mica has been investigated with respect to developing a simplified procedure, and controlling crystal size. Na-4-mica can be readily prepared using solid state synthesis procedures with reaction temperatures between 700 and 1100 °C. A simple ‘dry mix and calcine’ method (all-in-one method) has been found to yield essentially the same product as that obtained by the more complex multi-step procedure described previously in the literature. The level of potassium which can be exchanged into the Na-4-mica was found not to be critically dependent on the ion exchange capacity of the clay, as determined by alkylammonium ion exchange, but rather on the initial hydration state of the Na-4-mica.