EP 0426652 B1 19940511 - Process for the chlorine-free bleaching of pulp.
Title (en)
Process for the chlorine-free bleaching of pulp.
Title (de)
Verfahren zum chlorfreien Bleichen von Zellstoffen.
Title (fr)
Procédé exempt de chlore pour le blanchiment de pâtes cellulosiques.
Publication
Application
Priority
- AT 249489 A 19891030
- AT 258889 A 19891110
Abstract (en)
[origin: EP0426652A1] In the process for chlorine-free bleaching of pulps by means of ozone, a pulp suspension is contacted at a temperature of 15 - 80 DEG C, preferably 40 - 70 DEG C, and at a pH of 1-8, preferably 2-3, with an ozone-containing gas, while vigorously stirring or mixing. The ozone-containing gas contains 20-300 g/m<3>, preferably 50-150 g/m<3>, of ozone. At most 2% by mass, preferably 0.05 - 0.5% by mass, of ozone is used relative to absolutely dry pulp. In order to make this process suitable for a pulp suspension in the medium consistency (MC) range, i.e. for a pulp suspension having a stock consistency of 3 - 20% by mass, preferably 5 - 20% by mass and especially 7 - 15% by mass, the ozone-containing gas is introduced according to the invention under a pressure of 1 - 15 bar, preferably 1.1 - 10 bar, into the pulp suspension. The process can also be carried out in a multi-stage bleaching process once or several times. <IMAGE>
IPC 1-7
IPC 8 full level
D21C 9/00 (2006.01); D21C 9/10 (2006.01); D21C 9/153 (2006.01); D21C 9/16 (2006.01); D21H 17/00 (2006.01)
IPC 8 main group level
D21C (2006.01)
CPC (source: EP US)
D21C 9/153 (2013.01 - EP US); D21H 17/00 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE CH DE DK ES FR GB GR IT LI LU NL SE
DOCDB simple family (publication)
EP 0426652 A1 19910508; EP 0426652 B1 19940511; EP 0426652 B2 20011114; AR 243946 A1 19930930; AT E105599 T1 19940515; AU 636173 B2 19930422; AU 6455290 A 19910502; BG 51052 A3 19930115; BR 9005476 A 19910917; CA 2028788 A1 19910501; CA 2028788 C 19970415; DE 59005677 D1 19940616; DK 0426652 T3 19940613; ES 2023623 A4 19920201; ES 2023623 T3 19940801; FI 102194 B1 19981030; FI 102194 B 19981030; FI 905327 A0 19901029; GR 910300078 T1 19911210; HR P930459 A2 19960430; HR P930459 B1 19981231; HU 205175 B 19920330; HU 906923 D0 19910528; HU T55847 A 19910628; JP 2995422 B2 19991227; JP H03152286 A 19910628; LV 10513 A 19950220; LV 10513 B 19951020; NO 176975 B 19950320; NO 904673 D0 19901029; NO 904673 L 19910502; PH 30483 A 19970528; PT 95718 A 19910913; PT 95718 B 19971128; RO 107715 B1 19931230; SI 9012041 A 19970831; SI 9012041 B 20000630; TR 24891 A 19920701; UA 27098 A1 20000228; US 5346588 A 19940913; YU 204190 A 19920720; YU 47233 B 19950131
DOCDB simple family (application)
EP 90890291 A 19901030; AR 31820890 A 19901026; AT 90890291 T 19901030; AU 6455290 A 19901015; BG 9311090 A 19901029; BR 9005476 A 19901029; CA 2028788 A 19901029; DE 59005677 T 19901030; DK 90890291 T 19901030; ES 90890291 T 19901030; FI 905327 A 19901029; GR 910300078 T 19911210; HR P930459 A 19930323; HU 692390 A 19901029; JP 29096090 A 19901030; LV 930020 A 19930112; NO 904673 A 19901029; PH 41432 A 19901023; PT 9571890 A 19901029; RO 14618090 A 19901023; SI 9012041 A 19901029; TR 103190 A 19901026; UA 4831464 A 19901029; US 85923692 A 19920326; YU 204190 A 19901029