聚硅氯化铝(PASC)混凝剂的颗粒大小及分子量分布

The particle size and the molecular weight distribution of flocculant polyaluminum silicate chloride(PASC).

采用共聚与复合两种制备工艺，研制出碱化度（ Ｂ） 为２ ．０ 的具有不同 Ａｌ／ Ｓｉ 摩尔比的聚硅氯化铝（ 简称 Ｐ Ａ Ｓ Ｃ） 混凝剂．一种方法是将 Ｎａ Ｃｌ 加入到不同 Ａｌ／ Ｓｉ 摩尔比的 Ａｌ Ｃｌ３（６ Ｈ２ Ｏ 和聚硅酸混合液中；另一种方法是按一定的 Ａｌ／ Ｓｉ 摩尔比将聚硅酸加入到聚合氯化铝液中．应用光子相关光谱（ Ｐ Ｃ Ｓ） 和超滤膜过滤方法对 Ｐ Ａ Ｓ Ｃ 及聚合氯化铝（ Ｐ Ａ Ｃ） 的颗粒大小及分子量分布进行对比测定．结果表明，在 Ｐ Ａ Ｓ Ｃ 中，由于聚硅酸与铝水解聚合产物间的相互作用，生成了聚集体更大的聚合物，显著提高了聚集体的粒径，这种提高以共聚法最为明显； Ａｌ／ Ｓｉ摩尔比影响 Ｐ Ａ Ｓ Ｃ 的聚集度， Ａｌ／ Ｓｉ 摩尔比越小， Ｐ Ａ Ｓ Ｃ 的聚集度就越大．

A series of polyaluminum silicate chloride (PASC) with has basicity(B) 2.0 and different Al/Si molar ratio, was prepared by means of two kinds of preparation methods: one is to add NaOH into AlC l3 (6H 2O and polysilicic acid mixed solution at different Al/Si molar ratio, the other is to add polysilicic acid into polyaluminum chloride(PAC) solution with different B at different Al/Si molar ratio. The particle size and the molecular weight distribution of PASC and PAC were measured by means of physical photon correlation spectroscopy (PCS) analysis and ultrafiltration methods. The results show that the interaction between polysilicic acid and hydrolyzed aluminum species in PASC forms larger size polymer, which greatly increases the particle size of the polymer. The PASC prepared by the former method has higher molecular weight than the PASC prepared by the latter method. The Al/Si molar ratio affects the polymerization degree:the smaller the Al/Si molar ratio, the larger the polymerization degree of PASC.