Kinetics of the reaction of calcium sulfite with SO2

The kinetics of the reaction of CaSO3 with SO2 have been investigated in the temperature range 450–640°C. The reaction corresponds to the model of uniform attack of the reactant surface. Initial rates correspond to a control by interface chemical processes; activation energy is 30 Kcal. mol; the reaction is first order with respect to SO2. Diffusion, presumably solid state diffusion through the covering sulfate layer, progressively becomes strongly rate‐limiting, but the reaction can be conducted to completion.