SE9604469D0 - Alkaline treatment for metal ion removal during pulp bleaching - Google Patents
Alkaline treatment for metal ion removal during pulp bleachingInfo
- Publication number
- SE9604469D0 SE9604469D0 SE9604469A SE9604469A SE9604469D0 SE 9604469 D0 SE9604469 D0 SE 9604469D0 SE 9604469 A SE9604469 A SE 9604469A SE 9604469 A SE9604469 A SE 9604469A SE 9604469 D0 SE9604469 D0 SE 9604469D0
- Authority
- SE
- Sweden
- Prior art keywords
- pulp
- bleaching
- alkali
- concentration
- acid
- Prior art date
Links
- 229910021645 metal ion Inorganic materials 0.000 title abstract 3
- 238000004076 pulp bleaching Methods 0.000 title 1
- 239000003513 alkali Substances 0.000 abstract 4
- 238000004061 bleaching Methods 0.000 abstract 4
- 239000002253 acid Substances 0.000 abstract 2
- 239000012530 fluid Substances 0.000 abstract 2
- 238000000034 method Methods 0.000 abstract 2
- IAJILQKETJEXLJ-KLVWXMOXSA-N (2s,3r,4r,5r)-2,3,4,5-tetrahydroxy-6-oxohexanoic acid Chemical compound O=C[C@H](O)[C@H](O)[C@@H](O)[C@H](O)C(O)=O IAJILQKETJEXLJ-KLVWXMOXSA-N 0.000 abstract 1
- IAJILQKETJEXLJ-UHFFFAOYSA-N Galacturonsaeure Natural products O=CC(O)C(O)C(O)C(O)C(O)=O IAJILQKETJEXLJ-UHFFFAOYSA-N 0.000 abstract 1
- 239000000654 additive Substances 0.000 abstract 1
- 229920002678 cellulose Polymers 0.000 abstract 1
- 239000001913 cellulose Substances 0.000 abstract 1
- 239000002738 chelating agent Substances 0.000 abstract 1
- 150000001875 compounds Chemical class 0.000 abstract 1
- 239000000706 filtrate Substances 0.000 abstract 1
- 150000002500 ions Chemical class 0.000 abstract 1
- 239000002655 kraft paper Substances 0.000 abstract 1
- 238000004519 manufacturing process Methods 0.000 abstract 1
- 239000011368 organic material Substances 0.000 abstract 1
- 239000000126 substance Substances 0.000 abstract 1
- 230000008719 thickening Effects 0.000 abstract 1
- 238000005406 washing Methods 0.000 abstract 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/1005—Pretreatment of the pulp, e.g. degassing the pulp
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Paper (AREA)
Abstract
Method for treatment of cellulose pulp (for example Kraft pulp) before bleaching by utilization of bleaching chemicals that use metal ions to minimize or eliminate the need for chelating compound and alkali additives. The method consists of the following consecutive steps: (a) The pulp is treated in an acid step in order to remove the main part (preferably at least 80%) of the negatively loaded acid end-groups (typical hexuronic acid) from the pulp. (b) The pulp is treated after step (a) with an alkali source (preferably an alkali fluid containing liberated organic material in an amount of at least 5 kg/ton pulp, such as filtrate from an alkaline bleaching or delignifying step or black lye) containing components that combine with the positively loaded , bleaching chemical-utilizing metal ions for production of metal-content combinations. (c) The metal-content combinations are removed (washing and/or thickening step) from the pulp especially without or with a minimum amount of chelating compounds or added alkali. In step (a) the pulp has a typical concentration of approximately 8-20%, and this concentration is reduced by at least 3% to between approximately 5 - 8% in step (b) and the added alkaline fluid and pulp in the step (b) are held in contact with each other for at least 5 minutes (preferably 10 - 60 minutes) before step (c) is taken. The concentration of Fe<++> and/or Fe<+++> ions in the resulting pulp is below 15 ppm, preferably under 10 ppm.<IMAGE>
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US56666595A | 1995-12-04 | 1995-12-04 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| SE9604469D0 true SE9604469D0 (en) | 1996-12-04 |
| SE519548C2 SE519548C2 (en) | 2003-03-11 |
Family
ID=24263875
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| SE9604469A SE519548C2 (en) | 1995-12-04 | 1996-12-04 | Acid treatment followed by alkaline treatment for removal of metal ions when bleaching pulp |
Country Status (2)
| Country | Link |
|---|---|
| FI (1) | FI964843A (en) |
| SE (1) | SE519548C2 (en) |
-
1996
- 1996-12-04 SE SE9604469A patent/SE519548C2/en not_active IP Right Cessation
- 1996-12-04 FI FI964843A patent/FI964843A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| FI964843A0 (en) | 1996-12-04 |
| SE519548C2 (en) | 2003-03-11 |
| FI964843A (en) | 1997-06-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| NUG | Patent has lapsed |