Oxidized white liquor in an oxygen delignification process
US6691358B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 2002 |
| Grant date | Feb 17, 2004 |
| Priority date | — |
| Expiry date | Mar 15, 2022 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C11/0071
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The invention refers to a method for an integrated treatment of cellulose pulp. The method includes the steps: providing said cellulose pulp (1), providing a determined quantity of white liquor (2) including alkali and sulphur components, providing an oxygen-containing gas, oxidizing (5) the sulphur components of the white liquor by the supply of a part of said gas in such a way that at least a part of the sulphur is present in the form of sulphate, transporting the cellulose pulp having a certain kappa number to at least one mixing device (4), and supplying the oxidized white liquor from the oxidizing step to the cellulose pulp, supplying a part of said gas to the cellulose pulp in said mixing device, mixing the cellulose pulp with the oxidized white liquor and said gas in said mixing device, and transporting the cellulose pulp from said mixing device to a delignification reactor (6) for oxygen delignification of said cellulose pulp, wherein the kappa number is reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.