公开(公告)号：EP1161593A1

公开(公告)日：2001-12-12

申请号：EP00908150.6

申请日：2000-01-28

Applicant: STFI

Inventor： TORMUND, Disa ,  BERTHOLD, Fredrik ,  LINDSTRÖM, Mikael

IPC: D21C9/147

CPC classification number: D21C1/00 ,  D21C9/147

Abstract: A process for oxygen delignification of chemical pulp comprising an oxygen treatment unit operation stage in which the pulp is treated while suspended in an aqueous solution with oxygen in the presence of alkali, whereby the pulp consistency is less than 20%; more than 50 percentage by weight of the alkali consist of one or more carbonates; and the pH of the aqueous solution during the process is adapted to provide for the essential absence of bicarbonate in said solution during the treatment. Furthermore a process for the bleaching of chemical pulp comprising a peroxide bleaching unit operation stage and an oxygen delignification process of said kind.