Insights into catalytic effect of Fe~(3+)and MnO4 on SO2 absorption for phosphoric acid production by phosphate rock slurry

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作   者：

Na Gao;  Wenmin Qian;  Ping Ning; 

作者机构：

Kunming 650500;  Kunming University of Science and Technology;  China;  Faculty of Environmental Science and Engineering; 

关键词：

Phosphoric acid production;  Phosphorite slurry desulfurization;  Activation energy;  Catalytic mechanism;  Wet flue gas desulfurization;  Metal ions; 

期刊名称：

Separation and Purification Technology

i s s n：

1383-5866

年卷期：

2024 年 340 卷

页   码：

126541,2-11-

页   码：

摘   要：

Wet flue gas desulfurization(WFGD),which has been successfully applied to industrial production,is a technology designed to eliminate SO2 in the phosphorus chemical process.The SO2 absorbed by the WFGD process can replace concentrated sulfuric acid in typical phosphoric acid production,thereby reducing the production cost of phosphoric acid.In this paper,Fe~(3+)and MnO_4~-were used to enhance the removal efficiency of SO2 from phosphate slurry and co-produce phosphoric acid.It is found that under the optimal absorption conditions(3 wt % Fe(NO3)3)KMnO4 1000 mg/L),the time of 100 % SO2 absorption rate of the slurry reaches 3.5 h,and the maximum concentration of phosphate ions in the slurry is 3177.04 mg/L.DFT calculation shows that in the process of MnO_4~-enhanced liquid phase absorption of SO2,the hydration reaction of SO2 to H2SO3 occurs first,followed by H2SO3 catalyzes oxidation to H2SO4.Remarkably,the Fe~(3+)-MnO4 composite slurry can reduce the SO2 absorption barrier to 72.19 kJ/mol.This study provides a new method of phosphoric acid production by enhanced desulfurization of phosphate rock slurry,which greatly reduces the consumption of concentrated sulfuric acid in traditional phosphoric acid production through enhanced desulfurization of phosphate rock slurry.Simultaneously,this paper also holds potential value for exploring the mechanism of metal ions enhancing the SO2 absorption process.