Yang Lin, Wang Cheng, Yao Lu, Jiang Wenju, Jiang Xia, Li Jianjun
College of Architecture and Environment, Sichuan University Chengdu 610065 P. R. China
National Engineering Research Center for Flue Gas Desulfurization, Sichuan University Chengdu 610065 P. R. China.
RSC Adv. 2020 Jan 8;10(3):1430-1438. doi: 10.1039/c9ra09810k. eCollection 2020 Jan 7.
Manganese desulfurization has been increasingly explored, but the generated manganous dithionate (MD) by-product affects the valuable use of the desulfurized slurry. In this study, α-MnO, β-MnO, γ-MnO, and δ-MnO were prepared for MD removal in desulfurization manganese slurry. Results showed that δ-MnO had the best activity among the four because of its porosity and favorable surface properties. The operation conditions showed that 12.00 g L MD can be removed by more than 80.00% under the conditions of 1.4 mol L sulfuric acid, 100 g L δ-MnO dosage, and reaction at 90 °C for 3 h. The MD removal with MnO followed the decomposition-oxidation pass and direct oxidation-reduction reaction and consequently induced structure destruction and crystalline transfer. MD removal with natural MnO ore was also examined, and natural MnO ore in the δ type was found to have prominent activity. Thus, this type of natural MnO may serve as a good alternative to pure MnO for decreasing the cost of MD removal from desulfurization manganese slurry.
锰脱硫技术已得到越来越多的探索，但脱硫过程中产生的副产物连二硫酸锰（MD）影响了脱硫浆液的有效利用。本研究制备了α - MnO、β - MnO、γ - MnO和δ - MnO用于去除脱硫锰浆液中的MD。结果表明，δ - MnO因其孔隙率和良好的表面性质在这四种物质中活性最佳。操作条件表明，在1.4 mol/L硫酸、100 g/L δ - MnO用量以及90℃反应3 h的条件下，12.00 g/L的MD去除率可超过80.00%。MnO去除MD遵循分解 - 氧化途径和直接氧化 - 还原反应，进而导致结构破坏和晶体转变。还考察了天然MnO矿石对MD的去除效果，发现δ型天然MnO矿石具有显著活性。因此，这类天然MnO可作为纯MnO的良好替代品，以降低从脱硫锰浆液中去除MD的成本。
