METHOD FOR PRODUCTION OF BLEACHED WOOD-FIBROUS MATERIAL Russian patent published in 2019 - IPC D21B1/04 D21B1/06 D21B1/12 D21C9/10 

FIELD: paper production; cellulose production.

SUBSTANCE: invention relates to a method of producing bleached pulp of mechanical grinding, comprising steps of: a) splitting wood particles with size (15–50) mm × (15–50) mm × (6–12) mm, which if necessary were treated with chemical reagents and/or water, to obtain modified wood particles, b) grinding the modified wood particles obtained at step a) in one or more refiners, c) optionally, treating the cellulose mass obtained at step b) with oxidative or reducing bleaching agents, wherein step a) and / or step b) is carried out in the presence of composition Z, said composition Z contains one or more of (Z1): a dithionic acid salt H₂S₂O₄ (Z1), as well as if necessary additive (Z4) and wherein at step a) if necessary pre-treated wood particles first (i) subjected to mechanical pressure and/or shearing forces, and then (ii) grinding in refiner, wherein energy consumption and/or pressure in refiner from step a) (ii) is usually lower than corresponding parameters for refiner at step b).

EFFECT: invention also relates to a method of producing paper, bleached grinding pulp and use of bleached wood mechanical grinding to produce paper and wood materials.

7 cl, 2 tbl