| abstract |
According to the invention, polysulfide is used in the manufacture of kraft pulp in the initial stage of a displacement batch process in order to improve the yield. Polysulfide-containing white liquor is added intermixed with the first liquor charged to the digester, or as a separate charge before the impregnation liquor is introduced. Preferably, a cooking catalyst, e.g. antraquinone, is added to the white liquor charge as the cooking stage commences. |