聚合铝混凝过程研究:不同形态硅酸的影响作用

Coagulation of kaolin by PACl: the role of silica speciation

研究了不同形态硅酸对聚合铝混凝过程的影响作用 .实验结果表明经预制形成的具有不同形态分布组成的硅酸与聚合铝 ,在投加后相互间发生了十分复杂的物理化学作用 ,并受溶液pH值的影响 ,从而最终决定了混凝效果 .反应过程中所生成的形态产物及其物化特征 ,很大程度上取决于聚合铝碱化度以及所投加的Si Al比 .其中碱化度越高 ,最终产物所带电荷越高 .而不同硅酸所起影响作用分别取决于聚合程度 ,在与聚合铝反应过程中表现出一定的规律性 .单体硅酸与单体铝迅速发生较强的络合作用 ,抑制了多聚水解铝阳离子的形成 .聚合硅酸则倾向于与聚合铝形态相互作用形成一定的胶状化合物 ,从而在溶液中稳定存在 .对于胶体硅酸 ,在聚合铝作用下迅速凝聚形成更大的聚集体 ,在颗粒物间架桥形成粗大的絮体 .

The effect of speciation of silica on coagulation of kaolin with PACl was investigated in detail . The experimental results showed that the speciation components in silica and PACl samples have decisive effect on coagulation. The various species preformed undergo complicate interactions with each other after dosing, and the pH of the solution also play a main role. The final products formed correspond well with PACl applied. The higher the basicity (B), the higher the electrostatic charge for the final hydrolysis products. A certain trend has been observed that the interactions among PACl and silica are relatied to the polymerization contents. The results obtained provide useful information on the interpretation of coagulation mechanism and the further development for composite inorganic polymer flocculants