Study On Production Of Sulfuric Acid With Catalytic Oxidation Of SO₂ In Pyrolusite Slurry

MnO2, a good oxidizer, is the elemental component of pyrolusite. At the same time, SO2 is a good reducer. So there have been many reports on desulfurization using pyrolusite slurry. Most past reports are focused on the production of MnSO4 in the condition of lower liquid-solid ratio of slurry. On the contrary, there are few reports on the production of H2SO4 in the condition of higher liquid-solid ratio. Based on the reaction mechanics of catalytic oxidation of SO2 by transition metals, the paper discussed the effects of various reaction factors on the production of H2SO4, the optimal reaction condition and the reaction kinetics.There are six reaction factors that effect the production of sulfuric acid including the concentration of SO2, the concentration of O2, the liquid-solid ratio of slurry, space velocity, the reaction temperature and initial pH. The factors are test by orthogonal table . It is indicated in the orthogonal experiment that the most important three factors that effects the production of sulfuric acid are the liquid-solid of slurry, the reaction temperature and the concentration of O2, and the least important factor is the initial pH that can be ignored to the production of acid. In addition, it is showed that the highest concentration of sulfuric acid can be obtained when the liquid-solid ratio is 500:1. Furthermore, the result of single factor experiment revealed that the leaching velocity of Mn is much faster than that of Fe. That is to say, Mn2+ is the elemental factor that effects the production of acid.In the production of sulfuric acid, it can be easily satisfied that Ha<\. In thecondition, the reaction is controlled by kinetics. Based on the reaction mechanics of catalytic oxidation of SO2 by transition metals, the reaction kinetic equation of the production of sulfuric acid was established:The course of catalytic oxidation can be divided two phases, and the kinetic equations arerespectively Moreover, by study of the datum of experiment, a' and b are respectively given thatIn the end, the response model of the catalytic oxidation is established based on neural network. And the average error of the response model less than 21.2%. The model has some value of innovation and exploration to the research of catalytic oxidation of SO2 in pyrolusite slurry.