循环冷却水阻垢剂对脱硫石膏成核过程的影响

Effect of Circulating Cooling Water Scale Inhibitor on Nucleation Process of Desulfurized Gypsum

全厂废水零排放背景下,阻垢剂随循环排污水进入脱硫系统会阻碍石膏正常结晶。对不同阻垢剂工况进行石膏结晶实验,探究阻垢剂性能对石膏结晶成核特性的影响规律。结果表明:阻垢剂能够延长石膏结晶诱导时间,抑制石膏成核,阻垢剂质量浓度越高,石膏成核越困难;阻垢剂质量浓度为10 mg/L时,石膏结晶诱导时间增加17%~48%,成核抑制指数在7%~17%;阻垢剂F的成核抑制指数最小,其抑制成核作用最弱;添加阻垢剂D后的石膏晶体呈现片状,说明阻垢剂D的络合及分散性能强,严重抑制了石膏成核,添加阻垢剂F后的石膏晶体呈现粘连片状及针状,说明阻垢剂F的畸变性能强,成核受影响程度较低;石膏在结晶后加入阻垢剂的样品形貌表明,阻垢剂F的畸变性能最强;畸变性能强的阻垢剂对石膏成核过程抑制作用弱,成核抑制指数小,更适合全厂废水零排放背景下脱硫安全运行要求。

Under the background of zero discharge of wastewater in the whole plant,the scale inhibitors entering the desulfurization system with circulating sewage will prevent normal crystallization of gypsum.Gypsum crystallization experiments were performed with different scale inhibitors to explore the influence of scale inhibitor performance on nucleation characteristics of gypsum.Results show that scale inhibitor can prolong the induction time of gypsum crystallization and inhibit gypsum nucleation.The higher the mass concentration of scale inhibitor is,the more difficult the gypsum nucleation is.When the mass concentration of scale inhibitor is 10 mg/L,the induction time of gypsum crystallization increases by 17%to 48%,and the nucleation inhibition index ranges from 7%to 17%.The nucleation inhibition index of scale inhibitor F is minimum,and its nucleation inhibition effect is the weakest.After adding scale inhibitor D,the gypsum crystals appear as flakes,indicating that the complexation and dispersion performance of scale inhibitor D is strong,which seriously inhibited the gypsum nucleation.After adding scale inhibitor F,the gypsum crystals present as adhesive flakes and needle,indicating that the distortion performance of the scale inhibitor F is strong,and the nucleation is less affected.According to the morphology of gypsum samples with scale inhibitor added after crystallization,scale inhibitor F has the strongest distortion performance.Scale inhibitors with strong distortion performance have weak inhibitory effects on the gypsum nucleation process,and have a small nucleation inhibition index,which is more suitable for the requirement of the desulfurization safety operation.