THERMAL-BEHAVIOR AND DECOMPOSITION OF INTERCALATED KAOLINITE

Intercalation complexes of a Hungarian kaolinite were prepared with hydrazine 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 melting of potassium acetate intercalated in the interlayer spaces. Dehydroxylation occurred, in the presence of a molten phase, at a lower temperature than for the pure kaolinite. FTIR studies revealed that there is a sequence of dehydroxylation for the various OH groups of intercalated kaolinite. The reaction mechanism was followed up to 1000 degrees C via identification of the gaseous and solid decomposition products formed: H2O, CO2, CO, C3H6O, intercalated phases with basal spacings of 14.1 Angstrom, 11.5 Angstrom, and 8.5 Angstrom as well as elemental carbon, K4H2(CO3)(3) . 1.5H(2)O, K2CO3 . 1.5H(2)O, and KAlSiO4.