METHOD OF DELIGNIFICATION AND BLEACHING OF LIGNOCELLULOSE-CONTAINING PULP Russian patent published in 1997 - IPC

FIELD: pulp-and-paper industry. SUBSTANCE: lignocellulose- containing pulp is delignificated by a peracid or its salt, treated with complexing agent and then bleached with chlorine-free bleaching agent. may be performed with strongly oxidizing peracetic acid, whereas chlorine-free bleaching agent includes at least one peroxide- containing compound, ozone or sodium dithionite, or their mixtures. Delignification and treatment with complexing agent should be advantageously carried out at pH value close to neutral. Final bleaching may be effected by ozone and hydrogen peroxide. EFFECT: enhanced efficiency of process. 11 cl, 5 tbl