seen in framstellning of, inter alia, the oxygen bleached pulp

摘要

Oxypulp from the oxytower is diluted with recovered oxylye to achieve a suspension of 60kg oxypulp per m3. The oxylye residue diffuses out from the fibrous mass to the surrounding liquid during a process interuption of at least 5 mins, without liquid exchange. The suspension is stirred for 30-90 mins. Weak oxylye leaves the treated oxypulp which is then washed. The diffusion stage is operated until the level of active chlorine used in the subsequent bleaching sequence is reduced by at least 5% esp.10-30%.