PREPARATION OF WHITE LIQUOR PRODUCTION OF SULPHATE PULP Russian patent published in 2019 - IPC D21C11/00 

FIELD: chemistry.

SUBSTANCE: present invention relates to production of cellulose and can be used for regeneration of alkali liquors from black liquor solution during production of sulphate pulp. Set task is achieved by the fact that in preparation of white liquor production of sulphate cellulose, involving acidification of black liquor with sulphuric acid with separation of organic compounds containing lignin, followed by neutralization of the obtained solution with alkali, evaporation of solution to obtain solid phase of finished product, potassium sulphate and alkaline solution, which is absorbed by hydrogen sulphide to obtain white liquor, sent for pulping of process chips, wherein mother solution after separation of finished potassium sulphate product is absorbed by hydrogen sulphide fed from black liquor acidification stage, white liquor is prepared with sulphidity 55–85 % at ratio Na2S:NaOH 1:1–3:0.5, which is fed for process chips cooking.

EFFECT: achieved technical result consists in improvement of pulping process and quality of cellulose due to increased sulphidity, by control of reagents during preparation of white liquor for cooking of chips, simultaneous reduction of reagents consumption at maintaining quality of pulping.

1 cl, 3 ex