Description:
Expandable and non-expandable fluorine micas were synthesized by solid state reaction of talc with alkali fluosilicates ( Na2Sif6) or lithium fluoride (Lif) at he temperature between 700 and 900°c for 1 hour in an electronic furnace. Some physical properties of the synthetic micas depended on the kinds of alkali ions (Na, Li, K) in alkali fluosilicates or alkali fluoride. The basal spacings of the synthetic Na-and Li-micas saturated with ethylene glycol were in the range 16.9 to 17.0 A; The synthetic K-mica, however, did not show any expandable propoerties by ethylene glycol treatment. The results of dispersion and coagulation tests and zeta potential measurements of Na-and K-micas showed that each mica had different particle associations and electric potentials in water