Anionic trash in mechanical pulping systems

The bleaching reaction accounts for 80-90% of the anionic trash released du ring alkaline peroxide bleaching, while sodium silicate accounts for thr re maining 10-20%. Cationic papermaking chemicals that are recirculated to the mechanical pulping process in the filtrate loops may have a certain negati ve influence on the bleachability. Anionic trash accumulates in the filtrat e loops and its level in a mechanical pulp is 50-100 times higher than in a paper machine filtrate.