Polyferric sulfate is a kind of macromolecular ferric salt flocculant. When it is used, it is usually diluted with water. The 10% concentration of polyferric sulfate solution is a reddish brown transparent liquid with excellent dehydration effect. It is commonly used in urban sludge treatment.

After polyferric sulfate dehydrates municipal sludge, it will form a black soft solid with odor, which contains a lot of organic matter, nitrogen and phosphorus, heavy metals, pathogenic bacteria, etc. because the water content of sludge after dehydration is high, whether it is landfill, incineration, sea evacuation, etc., it will cause huge pollution to the environment because of the heavy metals, pathogens, nitrogen and phosphorus, etc. Through practice, people use PFS to mix with bituminous coal in high temperature environment and then feed dried sludge, which will be burned and decomposed under continuous high temperature. In this process, PFS can effectively eliminate the possible secondary pollution.

It is a relatively environmental protection treatment method to mix PFS and garbage through high temperature and sterilization incineration. The heat generated during incineration can be used in other processes to achieve the purpose of energy saving and environmental protection. Therefore, the new treatment method of PFS high temperature hot melting can realize the environmental protection treatment of sludge, reduce the cost and eliminate the secondary pollution.