EP 0693145 B1 19970917 - PROCESS FOR CONVERTING SODIUM SULPHATE
Title (en)
PROCESS FOR CONVERTING SODIUM SULPHATE
Title (de)
VERFAHREN ZUR UMWANDLUNG VON NATRIUMSULFAT
Title (fr)
PROCEDE DE CONVERSION DU SULFATE DE SODIUM
Publication
Application
Priority
- AT 9400038 W 19940331
- AT 68293 A 19930405
Abstract (en)
[origin: US5759345A] PCT No. PCT/AT94/00038 Sec. 371 Date Oct. 5, 1995 Sec. 102(e) Date Oct. 5, 1995 PCT Filed Mar. 31, 1994 PCT Pub. No. WO94/23124 PCT Pub. Date Oct. 13, 1994To recover the sodium-sulphur compounds following sodium-based pulp processing, e.g. the ASAM process or basic or acidic sodium sulphite processes, the waste liquor is burnt in a lye burning vat (1) with liquid slag extraction and the exhaust gases are subjected to multi-stage purification with dry fly-ash recovery and the gaseous sulphur compounds are also separated in a multi-stage washing process. The water-soluble components of the fly-ash are taken to the waste liquor to be burnt and thus the sulphur to be recovered in the slag is increased. The slag is dissolved in water and the dissolved sodium compounds are converted by multi-stage carbonisation with a part of the purified flue gas into sodium bicarbonate and H2S. The H2S is burnt and finally converted into sodium sulphite so that the desired lye for pulping cellulose can be made up from sodium sulphite and carbonate.
IPC 1-7
IPC 8 full level
D21C 11/00 (2006.01); D21C 11/04 (2006.01); D21C 11/06 (2006.01); D21C 11/12 (2006.01)
CPC (source: EP US)
D21C 11/0071 (2013.01 - EP US); D21C 11/04 (2013.01 - EP US); D21C 11/06 (2013.01 - EP US); D21C 11/066 (2013.01 - EP US); D21C 11/12 (2013.01 - EP US); D21C 11/127 (2013.01 - EP US)
Designated contracting state (EPC)
DE SE
DOCDB simple family (publication)
US 5759345 A 19980602; AT 398992 B 19950227; AT A68293 A 19940715; AU 6532294 A 19941024; CA 2160008 A1 19941013; CA 2160008 C 20010612; DE 59404103 D1 19971023; EP 0693145 A1 19960124; EP 0693145 B1 19970917; FI 954695 A0 19951003; FI 954695 A 19951003; WO 9423124 A1 19941013
DOCDB simple family (application)
US 54972795 A 19951005; AT 68293 A 19930405; AT 9400038 W 19940331; AU 6532294 A 19940331; CA 2160008 A 19940331; DE 59404103 T 19940331; EP 94912988 A 19940331; FI 954695 A 19951003