EP 0622491 A2 19941102 - Method for bleaching lignocellulose-containing pulp.
Title (en)
Method for bleaching lignocellulose-containing pulp.
Title (de)
Verfahren zum Bleichen von Lignozellulose-enthaltendem Zellstoff.
Title (fr)
Procédé pour le blanchiment de pâte à papier contenant de la lignocellulose.
Publication
Application
Priority
- SE 9301293 A 19930420
- SE 9301294 A 19930420
Abstract (en)
In a method for bleaching lignocellulose-containing pulp with a peroxide-containing compound, the pulp is, prior to the bleaching and in optional order, subjected to acid treatment at a pH of up to about 5 and treated with a complexing agent in order to release transition metal ions from their positions in the pulp. After the acid treatment, a magnesium compound and a calcium compound are added to the pulp at a pH of from about 3.5 to about 8 in order to reintroduce an optimum amount of magnesium and calcium ions into the pulp. The pulp is then bleached with a peroxide-containing compound at a pH of from about 7 to about 13.
IPC 1-7
IPC 8 full level
CPC (source: EP)
D21C 9/1005 (2013.01); D21C 9/1042 (2013.01); D21C 9/16 (2013.01)
Designated contracting state (EPC)
AT DE ES FR PT SE
DOCDB simple family (publication)
EP 0622491 A2 19941102; EP 0622491 A3 19950412; EP 0622491 B1 19990901; EP 0622491 B2 20020717; AT E184060 T1 19990915; BR 9401526 A 19941122; CA 2121387 A1 19941021; CA 2121387 C 19980630; DE 69420306 D1 19991007; DE 69420306 T2 20000420; FI 941764 A0 19940415; FI 941764 A 19941021; NO 302767 B1 19980420; NO 941421 D0 19940419; NO 941421 L 19941021
DOCDB simple family (application)
EP 94200924 A 19940405; AT 94200924 T 19940405; BR 9401526 A 19940418; CA 2121387 A 19940415; DE 69420306 T 19940405; FI 941764 A 19940415; NO 941421 A 19940419