The mechanism and kinetics of the desulphuration of basic aluminium-potassium sulphate in a mixture of H-2 and CO (3:1 by mole) was studied as a function of the pressure of the reducing mixture. The studies provided the temperature region of the process, the nature of all the solid and gaseous intermediate products, as well as the equations and the kinetic parameters describing the rate of desulphuration of the compound. Complex analysis of the obtained results permits the conditions of the process to be determined, i.e. the temperature and the composition of the gas phase, enabling aluminium oxide modifications of required specific properties to be manufactured.