METHOD FOR COLD REFINING OF CELLULOSE Russian patent published in 2023 - IPC D21C9/00 D21C3/02 

FIELD: paper industry.

SUBSTANCE: refining cellulose, used in the method for alkaline refining of cellulose. The method for refining cellulose includes processing the pulp with a sodium hydroxide solution in two stages, after which the treated pulp is kept in a refining tower, air-dry bleached pulp is used as pulp, while at the first stage of treatment with a solution of sodium hydroxide, the pulp mass is mixed while it is sprayed from nozzles in the volume of the mass with a solution of sodium hydroxide, mixing of the mass is carried out until the cellulose fibres are saturated with a solution of sodium hydroxide, at the second stage of treatment, with a solution of sodium hydroxide, the resulting reaction mass is sent to a rotary type apparatus in which the cellulose fibres are impregnated, accompanied by the destruction of the structure of mass fragments of cellulose by disintegration grinding of fragments of the mass with separation into fibres, which is carried out in the process of beating the cellulose fibres by the rotor of the rotary apparatus, in the refining tower, the reaction mass is kept for at least an hour, then washed and dried, while the method is implemented at the following ratio of the components of the reaction mass, in % by weight: cellulose 20-40; sodium hydroxide 11-23; water - the rest up to 100.

EFFECT: reduced specific consumption of sodium hydroxide, increased alpha-cellulose content by 4-9% for cellulose with an initial content of 88 wt.% while ensuring swelling at a level not exceeding 500% for viscose cellulose, and at a level not exceeding 730% - for cord.

2 cl, 7 ex, 1 tbl