化工学报2025，Vol.76Issue(4)：1484-1492,9.DOI:10.11949/0438-1157.20241192
湿法磷酸含氟尾气高效资源化利用热力学分析与工程实践
Thermodynamic analysis and engineering practice of high efficiently recycle of fluorine contained in tail gas from wet-process phosphoric acid plant
摘要
Abstract
For the extraction-concentration and tail gas washing fluorine release process of wet phosphoric acid,the gas-liquid distribution ratio of fluorine element under thermodynamic equilibrium of H2SiF6-H2O and H2SiF6-H3PO4-H2SO4-H2O systems was established,and the model prediction error was within 20％.Based on the thermodynamic analysis,reducing the tail gas washing temperature can increase the mass transfer driving force,improve the mass transfer rate of fluorine absorption and produce high concentration fluorosilicic acid solution,but the condensate water increases,which increases the water balance pressure of the system.A 75000 t P2O5/a WPA tail gas emission reduction and resource utilization project was designed and implemented.The unit operation of concentrating fluorosilicic acid by flash evaporation without pump was connected in series in the fluorine absorption circulating circuit.The low temperature and high concentration fluorosilicic acid is used to absorb and cool the tail gas below 323 K to make the fluorine-containing tail gas supersaturate and condense,which not only enhances absorption of the tail gas fluoride,but also avoids the loss of fluidity due to the agglomeration of silica particles.The results show that the fluorine content in tail gas is≤2 mg/m3,the recovery of fluorine in tail gas is≥99％,the total emission reduction of tail gas is more than 20％,and the H2 SiF6 is≥18％(mass)in the fluorosilicic acid product.An engineering example of high efficiently recycle of fluorine contained in tail gas from wet-process phosphoric acid plant is provided.关键词
湿法磷酸/氟/气液分配比/尾气/资源化/工程实践Key words
wet-process phosphoric acid/fluorine/gas-liquid distribution ratio/tail gas/recycle/engineering practice分类
化学化工引用本文复制引用
李季,王佳才,马永强,袁海斌,简路明,姜基灿,朱家骅..湿法磷酸含氟尾气高效资源化利用热力学分析与工程实践[J].化工学报,2025,76(4):1484-1492,9.基金项目
四川省科技计划项目(2023NSFSC1101,2023ZHJY0015) （2023NSFSC1101,2023ZHJY0015）
