METHOD OF PREPARATION OF CELLULOSE FOR NITRATION Russian patent published in 2018 - IPC D21C3/06 D21C9/00 D21C9/16 D21C11/00 D21C11/04 

FIELD: chemical industry.

SUBSTANCE: invention relates to the production of cellulose for chemical processing and can be used in the pulp and paper industry. Process for the production of cellulose for nitration, comprising acidifying a cellulose-containing raw material with a sulphite cooking liquor, neutralization of the spent acid brewing solution with the spent alkaline solution, hot refining of the sodium hydroxide cooking product and subsequent multistage bleaching, as an alkaline solution to neutralize the spent acidic cooking liquor use a mixture of spent alkaline solution from the previous stage of peroxide bleaching and desalinizing agent, taken in the amount of 0.015–0.020 % of the mass of the as. fibers, while the product is cooked for 20–30 minutes at a temperature of 70–80 °C, after this, the spent solution is removed for neutralization and hot refinement is carried out with sodium hydroxide in the presence of a desiccator, taken in an amount of 0.010–0.015 % by weight of the fibers. As a desalinator, a mixture containing anionic, non-ionic and amphoteric surfactant components, as well as a salt or salts from the group, including phosphates and sodium carbonates, disilicate and sodium sulfate. Refinement of the cooking product is carried out at a temperature of 95–99 °C, the duration of 40–60 minutes and the consumption of sodium hydroxide 4.0–4.5 % to the mass of absolutely dry fiber.

EFFECT: process for the production of cellulose for nitration, comprising acidifying a pulp containing a raw material with a sulphite cooking liquor, neutralization of the spent acid cooking liquor with the spent alkaline solution, hot refinement of the sodium hydroxide cooking product and subsequent multi-stage bleaching.

3 cl, 1 tbl