Y. Pelovski et V. Petkova, TRIBOCHEMISTRY AND KINETICS OF AL-2(SO4)(3)CENTER-DOT-XH2O DECOMPOSITION, Journal of thermal analysis, 43(1), 1995, pp. 339-349
The thermal decomposition of tribochemically activated Al-2(SO4)(3).xH
(2)O was studied by TG, DTA and EMF methods. For some of the intermedi
ate solids, X-ray diffraction and IR-spectroscopy were applied to lear
n more about the reaction mechanism. Thermal and EMP studies confirmed
that, even after mechanical activation of Al-2(SO4)(3).xH(2)O, Al2O(S
O4)(2) is formed as an intermediate. Isothermal kinetic experiments de
monstrated that the thermochemical sulphurization of inactivated Al-2(
SO4)(3).xH(2)O has an activation energy of 102.2 kJ.mol(-1) in the tem
perature range 850-890 K. The activation energy for activated Al-2(SO4
)(3).xH(2)O in the range 850-890 K is 55.0 kJ.mol(-1). The time of the
rmal decomposition is almost halved when Al-2(SO4)(3).xH(2)O is activa
ted mechanically. The results permit conclusions concerning the effici
ency of the tribochemical activation of Al-2(SO4)(3).xH(2)O and the ch
emical and kinetic mechanisms of the desulphurization process.