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US 9,540,767 B2Granted
Method for bleaching pulp
AssigneesKemira Oyj, Andritz Inc., Upm-Kymmene Corporation, Stora Enso OYJ, Metsa Fibre Oy
InventorsTapani Vuorinen, Anna-Stiina Jääskeläinen, Andreas Lindberg
Life of this patent
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Abstract
A method for bleaching pulp is provided. In the method at least one tertiary amine compound is introduced into a process stage of bleaching. This process stage is a stage which comprises mixing pulp and a chlorine compound capable of bleaching.
Claims19
A method for bleaching pulp which pulp contains hexenuronic acid, lignin or corresponding aromatic chemical structures, wherein at least one tertiary amine compound of the general formula (1)
- is introduced as catalyst into a process stage of bleaching that consists essentially of mixing pulp and a chlorine compound capable of bleaching, and wherein X is N or C, and R1-R12 is the same or different alkyl group, halide, ester, alkoxide or hydrogen wherein the amount of said tertiary amine compound is a catalytic amount from at least 0.01 kg/ton of pulp to less than 3 kg/ton of pulp.
Dependencies are inferred from the claim text.