Förfarande för framställning av oblekt massa med mycket låg COD

摘要

A pulp product that has a low COD is comprised of an unbleached pulp that is soaked and washed in alkaline water for a sufficient time so that the COD after soaking and washing is less than or equal to 3.0 kg/1000 kg of dry pul p. The pulp is produced by repetitively soaking and washing an unbleached pulp in alkaline water that is never allowed to drop below pH 7.0. The pulp is soake d and washed for a total of at least 400 minutes at an elevated temperature to produce the pulp product that has a low COD.