SE9800797D0 - Preparation of pulp - Google Patents

Preparation of pulp

Info

Publication number
SE9800797D0
SE9800797D0 SE9800797A SE9800797A SE9800797D0 SE 9800797 D0 SE9800797 D0 SE 9800797D0 SE 9800797 A SE9800797 A SE 9800797A SE 9800797 A SE9800797 A SE 9800797A SE 9800797 D0 SE9800797 D0 SE 9800797D0
Authority
SE
Sweden
Prior art keywords
acidic
pulp
filtrate
bleaching
washing
Prior art date
Application number
SE9800797A
Other languages
Swedish (sv)
Other versions
SE523084C2 (en
SE523084E (en
SE9800797L (en
Inventor
Klas Erik Norborg
Ingrid Maria Helena Sandberg
Original Assignee
Stora Kopparbergs Bergslags Ab
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=20410503&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=SE9800797(D0) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Stora Kopparbergs Bergslags Ab filed Critical Stora Kopparbergs Bergslags Ab
Priority to SE9800797A priority Critical patent/SE523084E/en
Publication of SE9800797D0 publication Critical patent/SE9800797D0/en
Priority to FI990531A priority patent/FI122773B/en
Publication of SE9800797L publication Critical patent/SE9800797L/en
Publication of SE523084C2 publication Critical patent/SE523084C2/en
Publication of SE523084E publication Critical patent/SE523084E/en

Links

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
    • D21C9/1026—Other features in bleaching processes
    • D21C9/1042—Use of chelating agents
    • 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
    • D21C9/12—Bleaching ; Apparatus therefor with halogens or halogen-containing compounds
    • D21C9/14—Bleaching ; Apparatus therefor with halogens or halogen-containing compounds with ClO2 or chlorites

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)

Abstract

Conditions are controlled in the acidic bleaching step to give a final pulp pH of 3 or above, then acid is added to the pulp prior to washing to reduce pH to a value at least 0.3 units less than the previous final pH value, and then an acidic filtrate is removed in a first washing step phase to remove metal ions capable of forming poorly soluble compounds. A continuous method for the preparation of pulp for papermaking, comprises cooking a fibrous material, delignifying it with oxygen and bleaching. The bleaching process used comprises an initial acidic bleaching step, followed by a washing step, from which at least one filtrate is removed, and at least some of the filtrate is used as dilution liquid to reduce pulp consistency following the acidic bleaching step. Conditions are controlled in the acidic bleaching step to give a final pulp pH of 3 or above, then for a pre-determined period before the washing step the pulp is treated at a pH at leas t 0.3 units less than this final pH value, by adding acid. The washing step is carried out using at least one initial washing phase where the filtrate removed is acidic. An Independent claim is also included for the above bleaching process, where acid is added to bring into solution materials capable of forming poorly soluble salts, which are then removed in ion form with the acidic filtrate in the washing step.
SE9800797A 1998-03-12 1998-03-12 Ways to continuously produce pulp and to increase the degree of closure in a bleachery SE523084E (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
SE9800797A SE523084E (en) 1998-03-12 1998-03-12 Ways to continuously produce pulp and to increase the degree of closure in a bleachery
FI990531A FI122773B (en) 1998-03-12 1999-03-11 Preparation of pulp

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE9800797A SE523084E (en) 1998-03-12 1998-03-12 Ways to continuously produce pulp and to increase the degree of closure in a bleachery

Publications (4)

Publication Number Publication Date
SE9800797D0 true SE9800797D0 (en) 1998-03-12
SE9800797L SE9800797L (en) 1999-09-13
SE523084C2 SE523084C2 (en) 2004-03-23
SE523084E SE523084E (en) 2006-09-29

Family

ID=20410503

Family Applications (1)

Application Number Title Priority Date Filing Date
SE9800797A SE523084E (en) 1998-03-12 1998-03-12 Ways to continuously produce pulp and to increase the degree of closure in a bleachery

Country Status (2)

Country Link
FI (1) FI122773B (en)
SE (1) SE523084E (en)

Also Published As

Publication number Publication date
FI990531A0 (en) 1999-03-11
SE523084C2 (en) 2004-03-23
SE523084E (en) 2006-09-29
FI990531A (en) 1999-09-13
SE9800797L (en) 1999-09-13
FI122773B (en) 2012-06-29

Similar Documents

Publication Publication Date Title
ATE130888T1 (en) METHOD FOR BLEACHING MATERIAL CONTAINING LIGNOCELLULOSE.
ATE210216T1 (en) METHOD AND ENZYMATIC PRODUCTION FOR TREATING PULP
FI941764A0 (en) Process for bleaching lignocellulosic pulp
ATE304075T1 (en) METHOD AND APPARATUS FOR THE REDUCTION OF VAK AND SULFUR DYES
SE9800797D0 (en) Preparation of pulp
DE69604365D1 (en) METHOD FOR PRODUCING PAPER
ES2100563T3 (en) METHOD OF TREATING WASTEWATER FROM THE PAPER INDUSTRY.
BR9406105A (en) Process water treatment method containing metal ions relative to the bleaching of pulp of material containing ligno-cellulose
ATE210219T1 (en) METHOD FOR PRODUCING PAPER PUSH
SE9701778L (en) Procedure for Minimizing Calcium Caused Incrustation Problems in Preparation of Bleached Cellulose Pulp
SE9102693L (en) PROCEDURES FOR OZONE WHITING OF MASS
SE9603630D0 (en) Pulp bleaching process
SE9702512D0 (en) Method when bleaching pulp
ATE150498T1 (en) METHOD FOR TREATING WOOD SANDS
SE9500926D0 (en) Pulp bleaching process
DE69915227D1 (en) Method and device for treatment of rejects
AU2001228335A1 (en) A method for treatment of flue gas cleaning products
SE9903416D0 (en) A process for the production of chemical pulp
FI950749A (en) Process for pre-treatment of pulp to be bleached with peroxide

Legal Events

Date Code Title Description
RPOP Patent has been republished in amended form after opposition
NUG Patent has lapsed