EP 1402111 A1 20040331 - A METHOD FOR TREATING CIRCULATION WATERS
Title (en)
A METHOD FOR TREATING CIRCULATION WATERS
Title (de)
BEHANDLUNGSVERFAHREN FÜR KREISLAUFWASSER
Title (fr)
PROCEDE DE TRAITEMENT D'EAUX DE CIRCULATION
Publication
Application
Priority
- FI 0200463 W 20020530
- FI 20011131 A 20010530
Abstract (en)
[origin: WO02097189A1] The present invention relates a method for the treating of circulation waters in papermaking processes wherein a stream of process water separated from an aqueous cellulosic pulp suspension of the papermaking process is provided, said separated process water having an elevated level of free calcium ions. A pH of not less than pH 9 is provided in the process water. Gaseous carbon dioxide is distributed in the process water in an amount sufficient for precipitating a substantial part of the calcium ions as solid calcium carbonate in the water and for obtaining a decreased level of free calcium ions in the water. The calcium ion depleted process water is returned to the papermaking process, thereby reducing or preventing the accumulation of calcium ions circulating in the process.
IPC 1-7
IPC 8 full level
D21C 11/00 (2006.01); C02F 5/02 (2006.01); D21F 1/66 (2006.01); D21H 17/01 (2006.01)
CPC (source: EP)
D21F 1/66 (2013.01); D21H 17/01 (2013.01)
Citation (search report)
See references of WO 02097189A1
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
DOCDB simple family (publication)
WO 02097189 A1 20021205; AT E423867 T1 20090315; DE 60231303 D1 20090409; EP 1402111 A1 20040331; EP 1402111 B1 20090225; FI 20011131 A0 20010530; FI 20011131 A 20021201
DOCDB simple family (application)
FI 0200463 W 20020530; AT 02774036 T 20020530; DE 60231303 T 20020530; EP 02774036 A 20020530; FI 20011131 A 20010530