Abstract: Introduction is made to a new type of sedimentation tank used in waste quenching water treatment, with the characteristics of high slenderness ratio and small land occupation, which features in high surface load and thick suspended sludge layer inside. Making use of return sludge as the substitute for coagulant, the sedimentation tank gives full play to coagulation effect and reduce the amount of added coagulants, helping to stabilize the water disposal procedure and enhance the quality of discharge water.

Key words: Waste quenching water, High efficiency sedimentation, Return sludge