工程研究-跨学科视野中的工程Issue(4)：398-403,6.DOI:10.3724/SP.J.1224.2015.00398
工业固废磷石膏矿化烟气反应体系中碳酸根离子浓度对碳酸钙形核的影响
Effect of Concentration of CO32-on Nucleation of CaCO3 in the Reaction System which Industrial Solid Waste Phosphogypsum Mineralize Flue Gas
摘要
Abstract
In the system of CaSO4·2H2O-NH3-CO2-H2O which flue gas CO2 is mineralized by solid waste phosphogypsum, the formation of CaCO3 through heterogeneous nucleation would decrease the reaction speed by raping around the surface of phosphogypsum. One improvement is to keep the homogeneous nucleation of CaCO3 in liquid phase by controlling the concentration of CO32–. In this study, initial specific molar concentration of Cr (the concentration of CO32–versus the solubility of CaSO4·2H2O) was designed as characteristic variable to study the nucleation of CaCO3 under fixed adding of CaSO4·2H2O whiskers and excessive amount of CO32–. The results showed that:when Cr<8, formation of CaCO3 were mainly through homogenous nucleation;while Cr>20, forma-tion of CaCO3 were mainly through heterogeneous nucleation. The nucleation could be theoretically explained by the reaction plane model based on the double film theory, in which the CaCO3 particles were supposed only pre-cipitated at a reaction plane in the diffusion layer. The relative distance between the reaction plane and the surface of CaSO4·2H2O was defined asφ, decreased as the increase of Cr and have a critical distance (φ0). When Cr<8, thenφ>φ0, formation of CaCO3 is homogenous nucleation in liquid phase;while Cr>20, thenφ<φ0, CaCO3 parti-cles formed on the surface of CaSO4·2H2O through heterogeneous nucleation. The results of this work contributed to the design of mineralization of CO2 with phosphogypsum.关键词
磷石膏/CO2矿化/均匀形核/非均匀形核/反应面距离Key words
phosphogypsum/mineralization of CO2/homogeneous nucleation/heterogeneous nuclea-tion/distance of reaction plane分类
化学化工引用本文复制引用
周加贝,陈昌国,朱家骅,夏素兰,王子宁,宫源..工业固废磷石膏矿化烟气反应体系中碳酸根离子浓度对碳酸钙形核的影响[J].工程研究-跨学科视野中的工程,2015,(4):398-403,6.基金项目
国家科技支撑计划课题 （）
