公开(公告)号：US20230212821A1

公开(公告)日：2023-07-06

申请号：US17928721

申请日：2021-06-14

Applicant: KEMIRA OYJ

Inventor： Leif ROBERTSEN ,  Jonas KONN

IPC: D21H21/02 ,  D21H17/37 ,  D21H17/45 ,  D21C9/08 ,  D21C9/14 ,  D21H11/04

CPC classification number: D21H21/02 ,  D21C9/086 ,  D21C9/142 ,  D21H11/04 ,  D21H17/375 ,  D21H17/455

Abstract: The invention relates to a method for pitch control and/or removal during bleaching of cellulosic fibres. Cellulosic fibres are obtained from a pulping process and formed into an aqueous cellulosic fibre suspension, and bleaching of the cellulosic fibre suspension is performed in a bleaching process comprising at least one acidic stage, where pH of the cellulosic fibre suspension is