Method of separating sodium hydroxide from white liquor or polysulfide liquor using diffusion dialysis
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Dec 1, 1998
Issued Date -
N/A
app pub date -
Feb 25, 1997
filing date -
Oct 20, 1993
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
The present invention relates to a method of processing white liquor obtained from the causticization stage of a pulp mill. According to the method, the white liquor, which principally contains sodium hydroxide (6) and sodium sulfide, is oxidized into polysulfide liquor (3), whereby the sodium sulfide is oxidized most advantageously with the help of a catalyst and an oxidizer such as air substantially into sodium polysulfide (7) and sodium thiosulfate. The method according to the invention is characterized in that the sodium hydroxide (6) contained in the white liquor is separated from the white liquor prior to the oxidizing step or from the polysulfide liquor (3) after the oxidizing step either entirely or partly by means of a diffusion dialysis process (4). The invention is further characterized in that the sodium hydroxide (6) separated from the white liquor is returned to the chemical circulation of the pulp mill.
First Claim
Family
International Classification(s)
- [Classification Symbol]
- [Patents Count]
Cited Art Landscape
Patent Citation Ranking
Advertisement
Advertisement
Advertisement
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully