摘要 |
FIELD: chemistry. ^ SUBSTANCE: polysulphide is obtained by the oxidation of sulphide-containing liquor in presence of the manganese compound used as catalyst and bismuth compound used as cocatalyst. During kraft pulping using the polysulphide-containing white liquor the cellulose mass is obtained by (i) white liquor oxidation in presence of the oxidation catalyst containing the manganese compound and cocatalyst containing bismuth compound, and (ii) cellulose mass delignification by oxidised white liquor containing the active polysulphide generated in stage (i). The oxidised white liquor containing active polysulphide is obtained by white liquor oxidation with oxygen-containing gas in presence of the manganese compound as catalyst and bismuth compound as cocatalyst. ^ EFFECT: increase of the process cycles amount. ^ 23 cl, 6 tbl, 6 ex |