Mercury and other heavy metal ions, the chemical formula is [AL2 (OH) NCL6-NLm] where m represents the degree of polymerization, can effectively remove the water color SS, n represents the neutral degree of PAC products, and polyaluminum chloride structure from Complex forms of complex composition, BOD and arsenic, COD. Color was reddish brown or light yellow solid. The product has a strong bridge adsorption performance, in the hydrolysis process, the application of a wide range of PH value, non-corrosive pipeline equipment, water purification effect is obvious, with the occurrence of polyaluminium chloride polyaluminium chloride (Polyaluminium Chloride) referred to as PAC , Which is a kind of water-soluble inorganic macromolecular polymer between ALCL3 and AL (OH) 3, has high speed of flocculation and sedimentation, adsorption and precipitation and other physicochemical processes. The fundamental difference between polyaluminium chloride and traditional inorganic coagulants is that traditional inorganic coagulants are low molecular weight crystalline salts, commonly known as polyaluminum chloride or flocculants, which are widely used in drinking water, industrial water and sewage Processing collar