Comparison of the TCF Bleachability of Ammonium Bisulfite Pulp with that of Magnesium Bisulfite Pulp, 1996 Pulping Conference Proceedings
Walter C. Erskine
Finch, Pruyn & Co., Inc
Paul R. Thomas
Paul Thomas Pulp Consulting
Azim Shariff
Econotech Services Ltd.
The bleaching of ammonium base and magnesium base bisulfite pulps of similar K No. derived from the same sample of mill chips by the common EopP European sequence showed a large difference in the bleachability of the two pulps. Under identical bleaching conditions, the brightness of the magnesium base pulp was over 20 points of ISO brightness higher than that of the ammonium base pulp and the viscosity of the magnesium base pulps was significantly higher than that of the ammonium base pulp Use of chelant and extra magnesium sulfate raised both brightness and viscosity for the ammonium based pulp but its brightness was still five points below that of the magnesium base bleached pulp.
Comparison of the TCF Bleachability of Ammonium Bisulfite Pulp with that of Magnesium Bisulfite Pulp
