湿法脱硫中石灰石溶解特性的实验研究

Experimental Study on Limestone Dissolution in Wet Desulphurization

石灰石的溶解特性对湿法烟气脱硫工艺具有十分重要意义。本文采用变pH值的方法考察了不同钙硫比(Ca/S)以及飞灰添加量对石灰石溶解特性的影响,并就其影响结果及其影响机理进行了理论分析。实验结果表明,溶液的pH值随着石灰石的加入而逐渐升高,且在较短反应时间内石灰石转化率就达到98%以上,少量飞灰的存在则对石灰石溶解有一定促进作用。石灰石的溶解速度和反应初期转化率均随着Ca/S及飞灰添加量的增加而提高,但当Ca/S比较高时,其对石灰石的溶解速度和反应初期转化率的影响不大。

Limestone dissolution is of significance to the wet flue gas desulfurization（WFGD） technology.In this paper,the effects of different Ca/S ratios and fly ash on limestone dissolution characteristics were investigated at a non-fixed pH value.The experimental results indicate that the pH value of solution increases as amount of limestone raised.The conversion of limestone has reached to 98% at the shorter reaction time.Moreover,a small amount of fly ash has been a great role in promoting limestone dissolution.Limestone dissolution rate and initial conversion are increased with the increase of Ca/S ratios and fly ash amounts.However,relatively large Ca/S ratio has little effect on the limestone dissolution rate and initial conversion.