EP 0511695 B1 19960828 - Process for bleaching of lignocellulose-containing pulp
Title (en)
Process for bleaching of lignocellulose-containing pulp
Title (de)
Verfahren zum Bleichen von Lignocellulose enthaltendem Zellstoff
Title (fr)
Procédé pour le blanchiment de pâte à papier contenant de la lignocellulose
Publication
Application
Priority
SE 9101301 A 19910430
Abstract (en)
[origin: EP0511695A1] The present invention relates to a process for delignification and bleaching of chemically digested lignocellulose-containing pulp, wherein the pulp is acid treated at a pH of between about 1 and about 6, whereupon a water-soluble compound containing an alkaline earth metal is added at a pH of between about 1 and about 7 before the pulp is treated with a chlorine-free bleaching agent. The chlorine-free bleaching agent includes peroxide compounds, ozone, oxygen and sodium dithionite in an optional sequence or mixture. After the treatment according to the invention, the pulp may be finally bleached to the desired brightness, suitably with a chlorine-free bleaching agent, such as ozone, to completely avoid formation and discharge of AOX.
IPC 1-7
IPC 8 full level
D21C 9/147 (2006.01); D21C 9/10 (2006.01); D21C 9/153 (2006.01); D21C 9/16 (2006.01)
CPC (source: EP)
D21C 9/1005 (2013.01); D21C 9/1036 (2013.01); D21C 9/153 (2013.01); D21C 9/163 (2013.01)
Designated contracting state (EPC)
AT BE CH DE ES FR IT LI PT SE
DOCDB simple family (publication)
EP 0511695 A1 19921104; EP 0511695 B1 19960828; EP 0511695 B2 20040602; AT E141971 T1 19960915; AT E173518 T1 19981215; AU 1514992 A 19930311; AU 651192 B2 19940714; BR 9201554 A 19921201; CA 2067296 A1 19921031; CA 2067296 C 19970304; DE 69213080 D1 19961002; DE 69227640 D1 19981224; DE 69227640 T2 19990506; EP 0679760 A1 19951102; EP 0679760 B1 19981118; ES 2091395 T3 19961101; FI 111964 B 20031015; FI 921886 A0 19920427; FI 921886 A 19921031; JP 2592747 B2 19970319; JP H05148784 A 19930615; MX 9201966 A 19921101; NO 180495 B 19970120; NO 180495 C 20030606; NO 921671 D0 19920429; NO 921671 L 19921102; NZ 242465 A 19931223; RU 2039141 C1 19950709; SE 470065 B 19931101; SE 470065 C 19960115; SE 9101301 D0 19910430; SE 9101301 L 19921031; ZA 923073 B 19921230
DOCDB simple family (application)
EP 92201005 A 19920408; AT 92201005 T 19920408; AT 94203640 T 19920408; AU 1514992 A 19920427; BR 9201554 A 19920428; CA 2067296 A 19920427; DE 69213080 T 19920408; DE 69227640 T 19920408; EP 94203640 A 19920408; ES 92201005 T 19920408; FI 921886 A 19920427; JP 13432592 A 19920428; MX 9201966 A 19920428; NO 921671 A 19920429; NZ 24246592 A 19920423; SE 9101301 A 19910430; SU 5011770 A 19920429; ZA 923073 A 19920428