不锈钢酸洗废液中金属氟化物的沉积机理研究

CRYSTALLIZATION KINETICS OF IRON AND CHROMIUM FLUORIDE HYDRATE FROM STAINLESS STRAIN STEEL PICKLING

采用添加晶种的方法诱导酸洗废液中的Fe、Cr离子发生结晶沉淀,以期达到回收金属的目的。主要研究了废酸液中Fe、Cr离子的沉积实验,并探讨了废酸液中Fe、Cr离子结晶沉淀动力学过程。实验结果表明,在低温条件下,离子沉积量相对较多。计算得到Fe F_3·3H_2O和Cr F_3·3H_2O的表观活化能分别为:E_a=64.13 k J/mol和E_a=67.00 k J/mol。实验结合模型确定了不同温度下的晶体生长线速度随过饱和度变化的关系,最佳的结晶沉淀温度在30℃,其次是50℃。

Induced deposition of Fe3＋ and Cr3＋ from stainless strain steel pickling was investigated. The Iron and chromium elements were recycled as form of FeF3·3H2O and CrF3 3H2O from pickling. The crystallization kinetics for heavy metals in pickling was analyzed. The results showed that the precipitation capacity of metal fluoride hydrates increased with lower temperature. The activation energy of FeF3·3H2O and CrF3·3H2O were 64.13 kJ/mol and 67.00 kJ/mol respectively. The crystal growing rate varied with super saturation was determined by combination of experiment and mathematic model. The simulation showed that the fastest crystal growing rate was at the temperature of 30℃, then by 50℃.