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1. WO1999060201 - PEROXIDE, OXYGEN, AND PEROXIDE/OXYGEN BRIGHTENING OF CHEMICAL AND MIXED WASTE PULPS

Publication Number WO/1999/060201
Publication Date 25.11.1999
International Application No. PCT/US1998/010070
International Filing Date 15.05.1998
Chapter 2 Demand Filed 14.12.1999
IPC
D21C 9/10 2006.01
DTEXTILES; PAPER
21PAPER-MAKING; PRODUCTION OF CELLULOSE
CPRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE- CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
9After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters
10Bleaching
D21C 9/147 2006.01
DTEXTILES; PAPER
21PAPER-MAKING; PRODUCTION OF CELLULOSE
CPRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE- CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
9After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters
10Bleaching
147with oxygen or its allotropic modifications
D21C 9/16 2006.01
DTEXTILES; PAPER
21PAPER-MAKING; PRODUCTION OF CELLULOSE
CPRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE- CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
9After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters
10Bleaching
16with per compounds
CPC
D21C 9/1036
DTEXTILES; PAPER
21PAPER-MAKING; PRODUCTION OF CELLULOSE
CPRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
9After-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
10Bleaching ; ; Apparatus therefor
1026Other features in bleaching processes
1036Use of compounds accelerating or improving the efficiency of the processes
D21C 9/147
DTEXTILES; PAPER
21PAPER-MAKING; PRODUCTION OF CELLULOSE
CPRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
9After-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
10Bleaching ; ; Apparatus therefor
147with oxygen or its allotropic modifications
D21C 9/163
DTEXTILES; PAPER
21PAPER-MAKING; PRODUCTION OF CELLULOSE
CPRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
9After-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
10Bleaching ; ; Apparatus therefor
16with per compounds
163with peroxides
Applicants
  • NATIONAL SILICATES PARTNERSHIP. [CA]/[CA] (AllExceptUS)
  • THE RESEARCH FOUNDATION OF STATE UNIVERSITY OF NEW YORK [US]/[US] (AllExceptUS)
  • EVANS, Timothy, D. [CA]/[CA] (UsOnly)
  • FRANCIS, Raymond, C. [CA]/[US] (UsOnly)
Inventors
  • EVANS, Timothy, D.
  • FRANCIS, Raymond, C.
Agents
  • LEWIS, Christopher, R.
Priority Data
Publication Language English (EN)
Filing Language English (EN)
Designated States
Title
(EN) PEROXIDE, OXYGEN, AND PEROXIDE/OXYGEN BRIGHTENING OF CHEMICAL AND MIXED WASTE PULPS
(FR) ECLAIRCISSEMENT DE PATES CHIMIQUES ET DE PATES DE VIEUX PAPIERS MELANGES, AU MOYEN DE PEROXYDE, D'OXYGENE OU DE PEROXYDE/OXYGENE
Abstract
(EN)
A composition and method for use in the peroxide, oxygen, or peroxide/oxygen stage of brightening pulps with less than 18 % lignin utilize a megnesium compound in a sodium silicate solution to form a higher percentage of high molecular weight silicates. Such high molecular weight silicates preferentially adsorb transition metal impurities which, if left in solution, would tend to decompose hydrogen peroxide and organic peroxides. Hydrogen peroxide is added to peroxide and peroxide/oxygen stages, while it is generated, along with organic peroxides, during an oxygen stage. Decomposition decreases the amount of peroxide that actually reacts with lignin and generates free radicals that attack the desired product, carbohydrate fibers. The high molecular weight silicates can be formed by using any magnesium compound which dissociates to form Mg(OH)+ cations, which in turn cause a silicate polymerization reaction. The formation of Mg(OH)+ cations from magnesium compounds occurs most realidy over a pH range of at least about 8 and preferably between about 8 and about 12. The magnesium compound is added in an amount to achieve an Mg:SiO2 mass ratio of between about 1:46 to about 1:2, and preferably between about 1:15 to about 1:3.
(FR)
L'invention concerne une composition et un procédé à utiliser dans la phase d'éclaircissement de pâtes contenant moins de 18 % de lignine, au moyen de peroxyde, d'oxygène ou de peroxyde/oxygène. Ledit procédé consiste à utiliser un composé de magnésium dans une solution au silicate de sodium, de sorte qu'un pourcentage plus élevé de silicates à poids molaire élevé soit produit. Lesdits silicates à poids moléculaire élevé adsorbent de préférence les impuretés constituées par les métaux de transition qui, s'ils restaient dans la solution, décomposeraient le peroxyde d'hydrogène et les peroxydes organiques. Du peroxyde d'hydrogène est ajouté aux étapes dans lesquelles du peroxyde et du peroxyde/oxygène sont utilisés, pendant qu'il est généré, conjointement avec des peroxydes organiques, au cours d'une étape d'utilisation d'oxygène. La décomposition réduit le taux de peroxyde qui réagit effectivement avec la lignine et génère des radicaux libres qui attaquent le produit souhaité, les fibres glucidiques. Les silicates à poids moléculaire élevé peuvent être produits au moyen d'un composé de magnésium, quel qu'il soit, qui se dissocie pour former des cations Mg(OH)+, qui à leur tour induisent une réaction de polymérisation des silicates. La formation de cations Mg(OH)+ à partir de composés de magnésium est plus facile à induire avec un pH d'environ 8, et de préférence d'environ 8 à 12. Le composé de magnésium est ajouté dans des proportions permettant l'obtention d'un rapport de masse Mg:SiO2 compris entre environ 1:46 et 1:2, et de préférence entre environ 1:15 à environ 1:3.
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