New Treatment and Cyclic Utility of Paper Mill Wastewater

The traditional semichemical process of making primary color paper board from yellow pulp is technically reconstructed.The high quality products can be obtainde in a water saving and consumption reducing process with less black liquid,which is stockpiled in sand pits and naturally evaporated to maintain a fixed level.The wastewater from the paper machines is kept in a close circulation,and then discharged regularly by the emission standard.This is very helpful to the water pollution in paper mills.