METHOD OF PROCESSING WASTE PAPER

摘要

Waste paper with a high lignin content is pretreated and delignified thereafter with oxygen (4). Prior to the oxygen step, the pulp (3) is dewatered whereby the main part of the white water (7) containing solved aluminium is used directly as dilution liquid in a subsequent paper mill (6). After the oxygen step (4) the pulp (5) is washed and dewatered whereby the white water (8) substantially free of aluminium is led off to evaporation and chemical recovery (9).