Study on the Activating Mechanism of Aluminum Potassium Sulfate in the Process of Hydration of Natural Anhydrite

The activating mechanism of aluminum potassium sulfate in the process of hydration of natural anhydrite was studied by adopting calcined alum KAl(SO4)2 and alum KAl(SO4)2·12H2O as activating agents in this paper.The results showed that the activating effect of the calcined alum is apparently higher than that of alum,and the former results in formation of intermediate products of K2Ca(SO4)2·H2O and K2Ca(SO4)2,while the latter leads to an intermediate product of K2Ca(SO4)2·H2O.When the hydration time is 3d and 5% of alum or 6% of calcined alum were used,their hydration rates reach 45.1% and 61.5% respectively.