Polyaluminium chloride is abbreviated as PAC, which is also commonly referred to as basic aluminum chloride or coagulant. It is a water-soluble inorganic polymer between alcl3al (OH) 3. The general chemical formula is [Al2 (OH) nCl6-n] m, where M represents the degree of polymerization and N represents the neutrality of PAC products. The color is yellow, dark brown and dark gray resin solid.
The main raw materials used in the current production process are: aluminum ore, bluestone, bauxite, aluminum oxide powder and hydrochloric acid. The iron content of bauxite affects the color of finished polyaluminium chloride. Due to the high price of bauxite with low iron content, many polyaluminium chloride manufacturers use bauxite with high iron content. The products produced in this way tend to composite polyaluminium ferric chloride, but the cost is relatively low. Hydrochloric acid is an essential raw material in the production of polyaluminium chloride. The quality of hydrochloric acid is directly related to the quality of polyaluminium chloride. Due to the high price of national standard hydrochloric acid, some polyaluminium chloride manufacturers use some industrial waste acid and national standard hydrochloric acid to be mixed for the production of polyaluminium chloride, such as pickling waste liquid, pesticide waste acid, etc. Due to the high content of iron ions in this kind of hydrochloric acid, the produced polyaluminium chloride also turns red. Therefore, the better color of polyaluminium chloride should be beige.
Polyaluminium chloride is a cationic inorganic polymer coagulant, which can achieve good flocculation effect on various wastewater, can quickly form large alum, has good sedimentation performance, has a wide range of suitable pH value (pH value 5-9), and the pH value and alkalinity of the treated water decrease less. When the water temperature is low, it can still maintain a stable flocculation effect, and its alkalinity is higher than other aluminum salts and iron salts. Therefore, the chemical solution has little erosion effect on the equipment. At the same time, it can also be used to remove heavy metals such as iron, manganese, chromium and lead in water, fluoride and oil in water, so it can be used to treat a variety of industrial wastewater. The effective dosage of the product is 20-50mg / L. Liquid products can be directly metered and added. Solid products need to be prepared into 10% – 15% solution in the dissolution tank and then metered and added according to the required concentration. Polyaluminium chloride has strong adaptability to treated water, especially for high turbidity water. When the water temperature is low, it can still maintain a stable coagulation effect.