Effects of Transition Metal Ions in Raw Materials on the Bleachability of Chemical Mechanical Pulps
In this study,three kinds of eucalyptus woods and three kinds of poplar woods,which were mainly used in the production of chemi-cal mechanical pulp,were compared with the difference of transition metal ion content in the pulp and the pre-impregnated residues.The effects of transition metal ions in the pulp on the bleachability and the effects of metal ions in the pre-impregnated residues on oxidation resis-tance were analyzed.The results showed that high contents of Mn2+in eucalyptus and the high contents of Fe3+in poplar resulted in poor bleach-ability of the pulp.The high contents of Fe3+in eucalyptus and poplar pre-impregnated residues led to the strong antioxidant properties,which resulted in high chemical consumption in actual production.For the completely removal of pre-impregnated residues,increasing the dosage of chelating agent had no significant effect on the bleachability of poplar,but had certain improvement on the bleachability of eucalyptus.For fully retained pre-impregnated residues,increasing the dosage of chelating agent had more obvious improvement on the bleachability than increasing the dosage of hydrogen peroxide.
chemical mechanical pulppulping materialmetal ionalkaline hydrogen peroxide bleachingpre-impregnated residue
万方数据
维普
