摘要:
A method for the manufacture of non-chlorine bleached pulp, from alkaline digested cellulose pulp, wherein a suspension of the cellulose pulp is subjected to a series to oxygen gas delignification (O), treatment with complexers (Q) and bleaching with non chlorine-containing oxidative bleaching agents (O,P,Z). The various treatment stages interspersed with washing and/or reconcentration of the cellulose pulp in at least one stage, in conjunction with which a suspension liquid is conveyed essentially in strict counter-current, with the result that the pulp manufacturing process is essentially totally closed with regard to the liquid circuit. The pH value of the suspension liquid, in the absence of a reduction agent, after oxygen gas delignification and onwards into the cellulose pulp treatment chain as far as the bleaching operation with the oxidative bleaching agent, is caused to attain a maximum of 10, and in that the carbonate content of the suspension liquid is caused to be the same as, or to exceed a certain lowest value depending on its position in the cellulose pulp treatment chain.