基于响应曲面法的反应-萃取-结晶工艺优化

Optimization of reactive extraction-crystallization process based on response surface methodology

氯化钙与二氧化碳通过反应-萃取-结晶工艺制备碳酸钙和氯化氢气体是制碱废液资源化利用的有效途径。用响应曲面中的Box-Behnken Design(BBD)设计实验,考察了氯化钙浓度、萃取剂体积分数、相比和温度4个因素对反应-萃取-结晶耦合工艺中氯化钙转化率、有机相中氯化氢浓度以及产物碳酸钙的平均粒度的影响及交互作用,并分别建立了三响应值与影响因素间的回归方程。三响应预测最佳值分别为:氯化钙转化率95.08%、有机相氯化氢浓度1.126 mol·L?1、碳酸钙平均粒度48.71?m;相应的实验值分别为92.35%、1.123 mol·L?1和49.14?m。预测值与实验值接近,误差较小,说明建立的模型对于反应-萃取-结晶工艺的分析和预测准确可靠。

The preparation of calcium carbonate and hydrogen chloride from calcium chloride and carbon dioxide by the reactive extraction-crystallization coupled process is an effective way for the utilization of alkaline waste liquid. In this paper, Box-Behnken Design（BBD） in response surface methodology was used to design the experiments to investigate the effects of concentration of calcium chloride（Ca Cl2）, volume fraction of extractant, phase ratio, and temperature on the conversion of Ca Cl2, concentration of hydrogen chloride（HCl） in organic phase, and the average particle size of calcium carbonate（Ca CO3） in the reactive extraction-crystallization coupled process, respectively. Three quadratic models were developed to correlate the variables to the response values and were proved to be significant. The optimal values were found as follows： conversion of Ca Cl2 95.08% and 92.35%, concentration of HCl in organic phase 1.126 mol·L？1 and 1.123 mol·L？1, and average particle size of Ca CO3 48.71 ？m and 49.14 ？m. The small errors between the predicted and experimental values showed that the established models were accurate and reliable for the analysis and prediction of the reactive extractioncrystallization process.