METHOD FOR RECYCLING CALCIUM SULFATE

摘要

Calcium sulfate is regenerated to lime at a relatively low temperature and in a short time. In a method of regenerating lime by reducing calcium sulfate by flowing a reducing gas containing 0.5 to 20% by volume of CO and 0.03 to 30% by volume of CO2, the reduction is carried out in the presence of an aid selected from the group consisting of Fe2O3, MgSO4 and mixtures thereof at a temperature of 900 to 1000 DEG C. In cases where the aid is Fe2O3, the amount thereof is 0.2 to 10% by weight based on the weight of the calcium sulfate in terms of anhydrous calcium sulfate. In cases where the aid is MgSO4, the amount thereof is preferably 10 to 50% by weight based on the weight of the calcium sulfate in terms of anhydrous calcium sulfate.