FIELD: pulp industry.
SUBSTANCE: invention relates to the production of cellulose. Task is achieved by neutralization of the solution after separation of organic compounds using sodium hydroxide directed from the step of absorbing an alkaline solution, and after the second evaporation step, potassium hydroxide is added at a ratio of NaOH:KOH 1:4, to obtain an end product of potassium sulphate, wherein the alkaline solution is absorbed by hydrogen sulphide fed from the black liquor acidification step to obtain white liquor with sulphidity of 55–85 %.
EFFECT: achieved technical result of the proposed invention consists in production of an additional product (potassium sulphate) with reduction of corrosive activity of the solution by introduction of sodium hydroxide, while improving the pulping process and the quality of cellulose by increasing sulphidity of white liquor of 55–85 %, thereby diversifying production while maintaining quality of pulping.
1 cl, 3 ex
