STUDIES ON THE THERMAL DISSOCIATIVE PROCE SS OF MICROCLINE

The microcline-CaSO4-CaO system was determined to be used to obtain K2 SO4 by thermodynamical analysing and computing lots of possible reacti ons of 6 microcline :systems. The effects of roasting temperature, tim e and ratios;of reactants on the potassium recovery of the microcline- CaSO4-CaCO3 were studied and the favorable conditions were determined as follow: 1323 K, 3.0 h, m(microcline) : m (CaSO4 . 2H(2)O) : m (CaCO 3) = 1 : 1 : 3. In the presence of 0.9% additive I, the roasting tempe rature decreased from 1323 K to 1223 K and the potassium recovery was 84%. Kinetic experimental data of the two systems with or without addi tive I both fitted a diffusion-through-product-layer-reaction model, a nd their kinetic equations were presented with apparent activation ene rgies 184.4 kJ . mol(-1) and 158.9 kJ mol(-1) respectively.