1987 Volume 41 Issue 3 Pages 241-248
Laboratory studies in soda quinone pulping of Douglas fir, pine (Akamatsu), eucalyptus and beech with direct causticized white liquor by ferric oxide (hereafter referred to as regenerated white liquor) were carried out in comparison with reagent white liquor pulping. Regenerated white liquor was made from hydrolysis of burning products of soda quinone pulping black liquor of softwoods and ferric oxide, and DDA (1, 4-dihydro-9, 10-dihydroxyanthracene sodium salt) was used as quinone with addition of 0.1% as AQ by weight on o.d. wood. Pulp yield and active alkali charge of regenerated and reagent white liquor pulping were almost equal at same Kappa number except eucalyptus pulp. Soda quinone pulping of eucalyptus was slightly disturbed by soluble aluminium salt in white liquor. Between regenerated and reagent white liquor, there were almost equal bleachability, pulp properties and Fe content of soda quinone pulp of four wood species.
