SE9602601L - Method of bleaching mechanical pulp in at least two steps - Google Patents

Method of bleaching mechanical pulp in at least two steps

Info

Publication number
SE9602601L
SE9602601L SE9602601A SE9602601A SE9602601L SE 9602601 L SE9602601 L SE 9602601L SE 9602601 A SE9602601 A SE 9602601A SE 9602601 A SE9602601 A SE 9602601A SE 9602601 L SE9602601 L SE 9602601L
Authority
SE
Sweden
Prior art keywords
bleaching
stage
mechanical pulp
bisulphite
refiner
Prior art date
Application number
SE9602601A
Other languages
Swedish (sv)
Other versions
SE9602601D0 (en
Inventor
Rita Ferritsius
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
Application filed by Stora Kopparbergs Bergslags Ab filed Critical Stora Kopparbergs Bergslags Ab
Priority to SE9602601A priority Critical patent/SE9602601L/en
Publication of SE9602601D0 publication Critical patent/SE9602601D0/en
Publication of SE9602601L publication Critical patent/SE9602601L/en

Links

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
    • D21B1/00—Fibrous raw materials or their mechanical treatment
    • D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
    • D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam
    • D21B1/14—Disintegrating in mills
    • D21B1/16—Disintegrating in mills in the presence of chemical 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
    • D21C9/1084—Bleaching ; Apparatus therefor with reducing compounds
    • 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
    • D21C9/147—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications

Landscapes

  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Paper (AREA)

Abstract

A process for bleaching mechanical pulp in at least two stages, of which the first stage is carried out at the same time as the wood raw material is broken down mechanically, comprises the following two stages: (1) a bleaching stage including at least one partial bleaching step carried out in combination with a refining step in a refiner, or during processing of the ground pulp, by adding 0.1-1.5 % bisulphite (equivalent to 1-15 kg/ADMT), with either the diluting water for the refiner or the spray water for grinding, so that bisulphite is present in the fibre liberation or processing step at a pH of 4-6.5 and a temperature less than 200 deg. C ; and (2) an oxidative or reductive bleaching stage. - Preferably peroxide or more preferably dithionite is added in stage (2).
SE9602601A 1996-06-28 1996-06-28 Method of bleaching mechanical pulp in at least two steps SE9602601L (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
SE9602601A SE9602601L (en) 1996-06-28 1996-06-28 Method of bleaching mechanical pulp in at least two steps

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE9602601A SE9602601L (en) 1996-06-28 1996-06-28 Method of bleaching mechanical pulp in at least two steps

Publications (2)

Publication Number Publication Date
SE9602601D0 SE9602601D0 (en) 1996-06-28
SE9602601L true SE9602601L (en) 1997-12-29

Family

ID=20403234

Family Applications (1)

Application Number Title Priority Date Filing Date
SE9602601A SE9602601L (en) 1996-06-28 1996-06-28 Method of bleaching mechanical pulp in at least two steps

Country Status (1)

Country Link
SE (1) SE9602601L (en)

Also Published As

Publication number Publication date
SE9602601D0 (en) 1996-06-28

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