FOERFARANDEFOERKAUSTICERINGAVGROENLUTIENALKALISKMASSAKOKNINGSPROCESS

摘要

A method for causticizing green liquor in an alkaline pulping process, advantageously in a sulphate process. The causticizing method comprises a primary causticizing process and a secondary causticizing process. In the primary causticizing process lime is added to the green liquor thereby forming white liquor and lime sludge. In the secondary causticizing process a substantial quantity of raw lime or lime otherwise of quality superior to that employed for the primary causticizing is added to the pre-causticized liquor, possibly after separation of the lime sludge, whereby after separation of lime sludge a white liquor of high causticity is obtained.