A process for synthesizing polymeric ferric sulphate using sulphur dioxide from coal combustion

We propose a process that uses sulphur dioxide from coal combustion as a raw material to snthesize polymeric ferric sulphate (PFS), a water treatment agent. The process uses sodium chlorate as an oxidant and ferrous sulphate Lis an absorbent. Sodium carbonate is used as the regulator of the polymerization process. The major chemical mechanisms in this reaction system include oxidation, hydrolysis, and polymerization. Oxidation determines sulpher conversion efficiency while hydrolysis and polymerization control the quality of product. Experiments have shown that the conversion efficiency of sulphur-dioxide with ferrous sulphate as an absorbent can be higher than 99 under appropriate process conditions. The temperature of the reaction system is an important factor affecting conversion efficiency of sulphur dioxide, Increasing temperature led to higher conversion efficiencies of sulphur dioxide. The basicity (a polymerization index for PFS) and total concentration in the PIS can be no less than 10% and 9% respectively, which are appropriate for efficient water treatment processes.