公开(公告)号：CA2070556A1

公开(公告)日：1992-12-09

申请号：CA2070556

申请日：1992-06-05

Applicant: DEGUSSA

Inventor： LEONHARDT WOLFGANG ,  SCHMIDT KURT ,  SUESS HANS U ,  GLAUM HOLGER

IPC: D21C9/10

Abstract: The present invention relates to a process for bleaching wood pulp, chemical pulp, or old paper, in which, prior to the actual bleaching stages, the fibre material to be bleached is treated with a natural or a synthetic zeolite or a lattice silicate and an organic complex-forming agent that is easily broken down, e.g., citric acid.

公开(公告)号：CA1144711A

公开(公告)日：1983-04-19

申请号：CA370899

申请日：1981-02-13

Applicant: DEGUSSA

Inventor： KRUEGER HORST ,  BERNDT WILHELM ,  SUESS HANS U

IPC: D21C9/16

Abstract: Pulps are bleached by an organic peracid in the acid range and subsequently by peroxide in the alkaline range. An acid produced from the corresponding carboxylic acid by reaction with hydrogen peroxide in the presence of a mineral acid is used as the peracid. The peroxide bleaching stage following the peracid bleaching stage is carried out after adding an amount of aqueous alkali solution required for carrying out the peroxide bleaching stage without intermediate washing of the cellulose of the pulp. No further peroxide is added.