Method for preparing composite flocculant by utilizing aluminum ash

The invention discloses a method for preparing a composite flocculant from aluminum ash. The method comprises four steps of fly ash treatment, aluminum ash treatment, polymeric flocculant preparation and composite flocculant preparation. According to the invention, based on the thought of fully utilizing byproducts, the fly ash and the aluminum ash are selected as main raw materials to prepare the polysilicate aluminum chloride flocculant, so that potential equipment corrosion caused by use of an iron flocculant is avoided; in order to further reinforce the flocculation effect of the flocculant, modified chitosan is used for further compounding, the obtained composite flocculant is good in flocculation effect, high-concentration and low-concentration heavy metal ions can be flocculated and removed at the same time, flocculation is completed within a few minutes, and the treatment efficiency is high. 本发明公开了一种利用铝灰渣制备复合絮凝剂的方法，所述方法包括粉煤灰的处理、铝灰渣的处理、聚合絮凝剂的制备、复合絮凝剂的制备四个步骤。本发明围绕着副产物充分利用的思路，本发明选择粉煤灰和铝灰渣为主要原料制备得到聚硅酸氯化铝类