METHOD AND A SYSTEM FOR WASHING PAPER PULP
The invention pertains to a method and system for washing pulp in a pulping process, wherein the pulp is washed in a pulp washer using aqueous wash liquor to obtain washed pulp and a wash filtrate comprising contaminants originating from the pulp and pulping process, wherein the method further comprises the steps of purifying said wash filtrate comprising contaminants from the pulp to provide purified wash liquor by flocculating said wash filtrate comprising contaminants originating from the pulp and pulping process; and separating the contaminants, as floc formed in the flocculation of said wash filtrate comprising contaminants originating from the pulp and pulping process, from the wash filtrate to provide purified wash liquor, the method further comprising re-circulating at least 25 mass-% of said purified wash liquor to the washer to be used as wash liquor, calculated from the total mass of said wash filtrate comprising contaminants originating from the pulp and pulping process.