Study on the mineralization and absorption of SO₂ in heavy metal smelting flue gas by the zinc oxide method

The mineralization and absorption of low concentrations of SO₂ in heavy metal smelting flue gas were studied by the zinc oxide method. The effects of ZnO concentration, SO₂ concentration, ventilation flow and slurry ZnSO₄ concentration on the zinc oxide desulfurization process were investigated by the spray and stirring reaction system. The results show that as the zinc oxide concentration increases from 0 to 0.05%, the effective desulfurization time is extended from 50 min to 180 min. When the zinc oxide concentration is certain, the effective desulfurization time is shortened with increasing SO₂ concentration, ventilation flow and slurry zinc sulfate concentration. In the process of desulfurization, the pH value change of the slurry can be divided into three stages: slow decline, rapid decline and basically unchanged, and the pH value drops from 6~7 to 2~3.