METHOD OF BLEACHING SULFATE CELLULOSE Russian patent published in 1999 - IPC

FIELD: pulp-and-paper industry. SUBSTANCE: sulfate cellulose is preliminarily treated with potassium permanganate in acid medium at pH 1.2-2.1. Consumption of permanganate is 0.1 to 4.0% of the weight of completely dry cellulose. Cellulose is washed with water and finally bleached in two steps with chlorine dioxide and then with hydrogen peroxide in presence of stabilizer. EFFECT: increased whiteness of cellulose to 86-88% in conditions of reduced cellulose concentration in suspension and lowered temperature of hydrogen peroxide treatment. 2 cl, 1 tbl, 9 ex