THERMAL-BEHAVIOR AND DECOMPOSITION OF INTERCALATED KAOLINITE

Intercalation complexes of a Hungarian kaolinite were prepared with hy drazine and potassium acetate. The thermal behavior and decomposition of the kaolinite-potassium acetate complex was studied by simultaneous TA-EGA, XRD, and FTIR methods. The intercalation complex is stable up to 300 degrees C, and decomposition takes place in two stages after m elting of potassium acetate intercalated in the interlayer spaces. Deh ydroxylation occurred, in the presence of a molten phase, at a lower t emperature than for the pure kaolinite. FTIR studies revealed that the re is a sequence of dehydroxylation for the various OH groups of inter calated kaolinite. The reaction mechanism was followed up to 1000 degr ees C via identification of the gaseous and solid decomposition produc ts formed: H2O, CO2, CO, C3H6O, intercalated phases with basal spacing s of 14.1 Angstrom, 11.5 Angstrom, and 8.5 Angstrom as well as element al carbon, K4H2(CO3)(3) . 1.5H(2)O, K2CO3 . 1.5H(2)O, and KAlSiO4.