Technique of catalytic oxidation flue gas desulfurization and hydrocarbonylation by-product polymerization iron sulfate

The catalytically oxidizing process for desulfurizing fume and co-producing polyferric sulfate includes: absorbing and dissolving SO2 from fume in a desulfurizing tower with ferrous sulfate solution as desulfurizing absorbent, catalytically oxidizing sulfite radical into sulfuric acid in the presence of O2 and iron ion as catalyst, reacting sulfuric acid and ferrous sulfate to co-produce liquid polyferric sulfate, and drying to obtain solid polyferric sulfate. The process has cheap desulfurizer, no waste discharge and obvious economic benefit, and is suitable for desulfurizing fume in boilers and other advantages.