Polyaluminum chloride (PAC) is white, light gray, light yellow or brown crystals or powders. The color varies with the production process and raw materials. It is slightly acidic. After dilution with water, aluminum hydroxide precipitates. In the hydrolysis process, physical and chemical processes such as electrochemistry, coagulation, adsorption and precipitation are accompanied, so as to achieve the purpose of water purification.
Polyaluminum chloride has the advantages of high adsorption activity, wide range of pH value, no need for coagulation aids and no influence of water temperature, etc. It is widely used in water purification treatment of domestic water, industrial water, etc.
In the mixed solution of aluminum sulfate and aluminum trichloride, lime and limestone are added to make sulfate ions and calcium form insoluble calcium sulfate precipitation, which is separated from the mixed solution to increase the aluminum-chloride equivalent ratio, thereby obtaining a certain aggregate polyaluminum chloride.
