Experimental research and commercial operation of zinc oxide process for treating low-SO_2 gas

Zinc oxide process for treating low-S02 gas is discussed with respects to its principle, experimental research and commercial operation. S02 is absorbed by a slurry containing ZnO at a pH of about 5 and resulting zinc bisulphite is decomposed by sulphuric acid or heating by steam to form high-concentration S02 gas and zinc oxide, which are reused in system, or zinc sulphate as a byproduct. Both experimental and commercial operation results proved that the process has high absorption efficiency and simple process flow, and is especially applicable to treating low-S02 off-gas or tail gas from sulphuric acid plant in zinc and lead smelter because of availability of ZnO absorbent.