基于响应面法优化的飞灰中氯盐磁化水浸出条件及机理研究

Study on conditions and mechanism for leaching chloride salt from fly ash using magnetized water based on response surface methodology

为提高磁化水体系下飞灰中氯盐的水洗去除效果,基于磁化水水浸飞灰中氯盐的单因素试验结果,采用响应面法设计了Box-Behnken试验,建立了线圈匝数、电流频率及固液比3个因素与飞灰中氯盐浸出率之间的数学模型,并优化了飞灰水浸氯盐工艺,结果表明,3个因素对氯盐去除效果的影响程度由大到小依次为固液比、线圈匝数、电流频率。在固液比为0.40、线圈匝数为116 N、电流频率为1.50 kHz的最佳工艺条件下进行了3次平行试验,飞灰中氯盐的浸出率平均值为92.90%,与模型预测值接近。对浸出溶液进行的表面张力和黏度检测分析结果表明,磁化预处理可以有效减小水的表面张力和黏度,从而强化氯盐的水浸效果。

In order to improve the water washing effect on removing chloride from fly ash in magnetized water system,based on the single factor testing results of removing chloride by leaching fly ash with magnetized water,the Box-Behnken tests were designed by using response surface method.The mathematical model between the three factors:coil turns,current frequency,solid-liquid ratio and the leaching rate of chloride from fly ash was established,and the process of leaching chloride from fly ash was optimized.The results show that the influence degree of the three factors on the removal of chloride ranked as solid-liquid ratio,turns per coil and current frequency.Three parallel tests were carried out under the optimum process conditions which was solid-liquid ratio of 0.40,coil turns of 116 N and current frequency of 1.50 kHz.The averaged leaching rate of chloride from fly ash was 92.90%which approximated to the predicted results of the model.The surface tension and viscosity of the leaching solution were determined and analyzed.The results indicated that the magnetization-based pretreatment is likely to lower the surface tension and viscosity of the water efficiently so as to improve the water leaching rate of the chloride salt.