PROCESSO PARA REMOVER A COR DE UMA POLPA PREPARADA A PARTIR DE MATERIAL DE PAPEL DE REFUGO E PRODUTO OBTIDO

摘要

Color is removed from secondary pulps with non-chlorine based bleaching agents in treating sequences using oxygen with combinations of peroxide, ozone, and/or hydrosulfite at controlled pH conditions. Acid treatment prior to bleaching steps improves color removal and protects fibers from damage at more severe bleaching conditions.