METHOD OF CHORINELESS BLEACHING SYNTHETIC CELLULOSE Russian patent published in 1998 - IPC

FIELD: pulp- and-paper industry. SUBSTANCE: method includes transferring cellulose suspension on bleaching line and at least one treatment of it with acid at pH below 7. Suspension is fed into at least one bleaching vessel in bleaching line and subjected to at least single- step bleaching until whiteness degree higher than 75% is attained using 5 g of hydrogen peroxide per 1 t of completely dry cellulose or corresponding amount of another peroxide at elevated temperature and pressure exceeding 2 bar. Area of the bleaching vessel cross-section exceeds 3 sq.m and area of inner metal surface of vessel is below 4V sq.m where V is volume of vessel, cu.m. EFFECT: increased efficiency and uniformity of bleaching. 32 cl