EP 1365993 A1 20031203 - PROCESS FOR REDUCTIVE BLEACHING OF ALKALINE EARTH METAL CARBONATES
Title (en)
PROCESS FOR REDUCTIVE BLEACHING OF ALKALINE EARTH METAL CARBONATES
Title (de)
VERFAHREN ZUM REDUKTIVEN BLEICHEN VON ERDALKALI KARBONATEN
Title (fr)
PROCEDE DE BLANCHIMENT REDUCTEUR DE CARBONATES DE METAL ALCALINO-TERREUX
Publication
Application
Priority
- GB 0103500 A 20010213
- US 0204168 W 20020213
Abstract (en)
[origin: WO02064505A1] A process for improving the brightness of an alkaline earth metal carbonate utilizing formamidine sulfinic acid or sodium dithionite as a reductive bleaching agent is disclosed. Where the alkaline earth metal carbonate is calcium carbonate, addition of the reductive bleaching agent to an aqueous slurry of the calcium carbonate takes place prior to, during, or after formation of the carbonate, which is chosen from at least one of a precipitated calcium carbonate and a ground calcium carbonate.
IPC 1-7
IPC 8 full level
C01B 32/60 (2017.01); C01F 5/24 (2006.01); C01F 11/18 (2006.01)
CPC (source: EP)
C01B 32/60 (2017.07); C01F 5/24 (2013.01); C01F 11/183 (2013.01); C01F 11/185 (2013.01); C01P 2004/61 (2013.01); C01P 2004/62 (2013.01); C01P 2006/60 (2013.01)
Citation (search report)
See references of WO 02064505A1
Citation (third parties)
Third party :
- US 2520850 A 19500829 - JOHN MINNICK LEONARD
- US 6211400 B1 20010403 - BERGHOFER JOSEF [DE], et al
- EP 0844988 A1 19980603 - DORFNER GMBH & CO KAOLIN UND K [DE]
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 02064505 A1 20020822; CA 2438039 A1 20020822; EP 1365993 A1 20031203; GB 0103500 D0 20010328
DOCDB simple family (application)
US 0204168 W 20020213; CA 2438039 A 20020213; EP 02714877 A 20020213; GB 0103500 A 20010213