Acid treatment of pulp at high temperature prior to chlorine dioxide bleaching
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Oct 23, 2001
Grant Date -
Jun 21, 2001
app pub date -
Apr 14, 1998
filing date -
Oct 20, 1995
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
In the treatment of cellulose pulp in connection with bleaching, the pulp is first cooked and, if necessary, oxygen delignified in order to reduce the Kappa number below 24, preferably below 14, and after that the pulp is treated in an acid stage at a pH of 2-5 and at a temperature range of 75-130.degree. C. in order to reduce the Kappa number by 2-9 units. To prevent essential weakening of the strength properties of the pulp in the acid stage treatment tower, the retention time, t min, is 30 to 300 minutes and the treatment temperature, T.degree. C. is T.sub.min
Recipient Email Address Recipient Email Address Comment Recipient Email Address 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
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Add to Portfolio(s)
