Experimental Study on Effect of Inhibitors on Oxidation Kinetics of Calcium Sulfite under Heterogeneous Condition

摘要

Uncatalyzed oxidation kinetics of calcium sulfite, the residual product from wet limestone scrubbing, was studied under heterogeneous condition. Effect of Inhibitors on calcium sulfite oxidation kinetics was investigated varying pH, concentration of calcium sulfite, oxygen partial pressure, concentration of inhibitors and temperature. It was proposed that inhibitors (alcohols, phenols and hydroquinone) could affect the reaction rate by eliminating the free radicals, which were produced in the course of chain reaction. The common characteristic of the inhibitors was that they had active hydroxy radicals and reducibility. The mechanism of inhibition was different from EDTA, which could restrain the catalysis of metal ions. Furthermore, it was concluded that the uncatalyzed oxidation was chain reaction of free radicals, which could be produced without metal ions or UV in the experimental conditions. Thus, the theory was provided for design of the controlling oxidation technics.