Factors Affecting Slurry Oxidation in a Wet Flue Gas Desulfurization Process

At present, wet flue gas desulfurization (FGD) systems offer insufficient control of the oxidation process. This study proposes to optimize the oxidation process of desulfurization slurry by an oxidation reduction potential (ORP) control strategy. By designing a L16(45) orthogonal test, the effects of temperature, concentration, rotation speed, air flow rate, and pH on ORP were investigated at different oxidation stages of CaSO3. Based on the analysis of variance, the order of contribution of different influencing factors at the specific oxidation stage was obtained. The influence degree of specific influencing factors on ORP was different, and the trend is explained for each different oxidation stage as well. The results indicate that only the temperature plays a significant role in the change of ORP during the whole oxidation process, which clarifies that the temperature affects the oxidation process of CaSO3 by affecting the dissolution of O2 and CaCO3 and the transformation of S(IV) to S(VI). The results also provide theoretical guidance for precise oxidation control of the FGD slurry system.