This paper describes polymerization of anilinium-DBSA complex to PANI-DBSA (DBSA doped polyaniline) in an aqueous dispersion in the presence of mica or talc clays. It is found that the clay presence significantly accelerates the polymerization kinetics by metal ions, such as Fe+2 ions, present in the clays. Polymerization occurs preferentially on the clay particles' surface, causing their encapsulation with PANI-DBSA shells. Further coating with PANI-DBSA takes place on the already coated particles with thin PANI-DBSA shells by an autoacceleration effect of anilinium-DBSA polymerization by PANI. It is suggested that the catalytic/autoacceleration effect dominating in the coating process of clay particles with PANI-DBSA can be extended to other particle/coating systems, which are already under investigation.