响应面分析法优化从钛白废酸中提取钪元素的工艺参数

Optimization of Technological Parameters for Extraction of Scandium from Titanium Oxide Waste Acid by Response Surface Analysis

采用响应面分析法优化二(2-乙基己基)磷酸-磷酸三丁酯-磺化煤油复合萃取剂提取钛白废酸中Sc元素的工艺参数。以现有工艺条件为基础,确定响应面实验因素和中心水平;根据Box-Benhnken Design中心组合实验设计原理,选取溶剂比(萃取剂与废酸的质量比)、萃取时间和静态循环次数进行三因素三水平中心组合设计实验;以纯化倍数为响应值,以Sc回收率大于99%为约束条件,分析各因素的显著性和交互作用。实验结果表明,溶剂比与萃取时间的交互作用显著;最优工艺参数为:溶剂比0.11,萃取时间13.87 min,循环次数2;在此条件下,Sc回收率为99.00%,纯化倍数为61.61。对实验数据进行多元回归拟合,得出纯化倍数的二次多项回归模型,该模型的准确度和精密度均较高。

The synergistic extraction of scandium from titanium oxide waste acid was optimized by means of the response surface analysis （RSA） with di （2-ethyl-hexyl）phosphoric acid-tributyl phosphate-sulfonated kerosene composite extractant. Based on the actual process conditions, solvent ratio （the mass ratio of the extractant to the waste acid）, extraction time and number of cycles were selected as response surface experiment factors. According to the Box-Benhnken Design principle, the RSA method with 3 factors and 3 levels was used and the purification factor was determined as response value, with scandium recovery rate of more than 99.00% as constraint. The results showed that, the interaction between the solvent ratio and extraction time was the strongest. Under the optimum experimental conditions of solvent ratio 0.11, extraction time 13.87 min and cycle number 2, the scandium recovery rate reached 99% and the purification factor was 61.61. A quadric polynomial regression model with high accuracy and precision for the purification factor was established based on the experimental data.