磷尾矿脱除二氧化硫的实验研究

Experimental study on removal of sulfur dioxide by phosphorus tailings

为了丰富废弃磷尾矿的资源化利用途径,以浮选磷尾矿为脱硫剂,研究了湿法脱硫过程中固液比、吸收剂温度、进口SO2质量浓度以及经煅烧、微波处理等影响因素对脱硫效率的影响规律。结果表明,最佳反应温度为25℃,随着温度升高,SO2溶解度降低,吸收液对SO2去除效率降低;固液比增加,吸收剂与SO2接触面积增大,脱硫率增加;进口SO2质量浓度的提高大量消耗吸收液中的氢氧根,降低了吸收液的p H,不利于SO2的吸收;磷尾矿经煅烧后物化性质发生变化,最显著的是原有的碳酸盐等盐类转化为金属氧化物,提高了反应活性,大大提高了脱硫效率;微波处理后的磷尾矿由于降低其活化能,在一定程度上提高了反应速率,有利于SO2的吸收。

In order to enrich the utilization ways of waste phosphorus tailings,flotation phosphorus tailings are used as desulfurizers.The effects of factors in the wet desulphurization process,such as solid-liquid ratio,absorbent temperature,SO2 mass concentration at the inlet,calcination and microwave treatment on the desulfurization efficiency are studied.Results show that the optimum reaction temperature is at 25℃.With the increasing temperature,the solubility of SO2 decreases,and the removal efficiency of SO2 by absorbent solution also drops.As solid-liquid ratio increases,the contact area between the absorbent and SO2 also increases,and then the desulfurization rate has a significant rise.However,the rise of SO2 mass concentration at the inlet will cause the consumption of OH-in absorbent solution to increase,thus reducing the p H of absorption solution,which is not conducive to the absorption of SO2.After calcination,the physicochemical properties of the phosphorous tailings have changed,the original carbonates and other salts are converted into metal oxides,which improves the reactivity and desulfurization efficiency of phosphorus tailings.Meanwhile,phosphorus tailings after microwave treatment can enhance the reaction speed due to a reduction of activation energy,which is beneficial to the absorption of SO2.