EP 0018287 B1 19830112 - PROCESS FOR THE DELIGNIFICATION OF UNBLEACHED CHEMICAL PAPER PULP
Title (en)
PROCESS FOR THE DELIGNIFICATION OF UNBLEACHED CHEMICAL PAPER PULP
Publication
Application
Priority
- FR 7909642 A 19790417
- FR 8007170 A 19800331
Abstract (en)
[origin: CA1151363A] PATENT APPLICATION entitled: Process for the delignification of unbleached chemical pulp. in the name of: Groupement d'Int?r?t Economique styled: GROUPMENT EUROPEEN DE LA CELLULOSE. The invention relates to a process for the delignification of unbleached chemical pulp, comprising the following stages: a) oxidation of the unbleached pulp with a peroxide, in an alkaline medium with a % ratio of peroxide/pulp with respect to the Kappa index of said pulp which may vary between 0.01 and 0.1 and a pH kept at between 9 and 12, the said oxidation stage being followed by b) mechanical pressing of the oxidized pulp, with recycling of the extraction effluents from the pressing stage, - partly above the oxidation stage, - partly-below the oxidation stage, with a view to ensure the prior dilution of the pulp oxidized before the pressing, - and if necessary partly towards the wash of the unbleached pulp. Advantages: A reduction in the quantities of reagents to be used, a saving of heat energy and a reduction of the pollution. Figure 1
IPC 1-7
IPC 8 full level
D21C 9/16 (2006.01)
CPC (source: EP US)
D21C 9/163 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE DE IT SE
DOCDB simple family (publication)
EP 0018287 A1 19801029; EP 0018287 B1 19830112; AU 539108 B2 19840913; AU 5745080 A 19801023; BR 8002356 A 19801202; CA 1151363 A 19830809; DE 3061582 D1 19830217; FI 67242 B 19841031; FI 801211 A 19801018; NZ 193456 A 19820629; OA 06515 A 19810731; US 4462864 A 19840731
DOCDB simple family (application)
EP 80400516 A 19800416; AU 5745080 A 19800415; BR 8002356 A 19800416; CA 349872 A 19800415; DE 3061582 T 19800416; FI 801211 A 19800416; NZ 19345680 A 19800416; OA 57086 A 19800416; US 36814282 A 19820414