PROCESS FOR PREPARING KRAFT PULP BY TREATING THE LIGNIN-CONTAINING CELLULOSIC MATERIAL WITH RECYCLED PULPING PROCESS LIQUIDS, UNCAUSTICIZED COOKING LIQUOR AND CAUSTICIZED WHITE LIQUOR

摘要

An improved batch process for preparing kraft pulp is disclosed, wherein a portion of green liquor or a derivative thereof is introduced in the impregnation or/and pretreatment stage. The derivative may be mother liquor originating from crystallization of carbonate from green liquor. The procedure facilitates the use of mild conditions in the final cooking stage and short cooking periods and results in higher pulp quality, high production output and good maintenance of the balance of chemicals in the mill. IMAGE