EP 0679760 A1 19951102 - Process for bleaching of lignocellulose-containing pulp.
Title (en)
Process for bleaching of lignocellulose-containing pulp.
Title (de)
Verfahren zum Bleichen von Lignocellulose-enthaltendem Zellstoffen.
Title (fr)
Procédé pour le blanchiment de pâte à papier contenant de la lignocellulose.
Publication
Application
Priority
- EP 92201005 A 19920408
- SE 9101301 A 19910430
Abstract (en)
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 mixture of a magnesium compound and a calcium compound 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 hydrogen peroxide. 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)
Citation (search report)
- [Y] US 3507744 A 19700421 - GRANGAARD DONALD H
- [Y] EP 0148712 A1 19850717 - ATOCHEM [FR]
- [A] DE 2022866 A1 19701223 - MO OCH DOMSJOE AB
- [A] DATABASE WPI Section Ch Week 9118, Derwent World Patents Index; Class E37, AN 91-127527
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