Evaluation of bleachability on pine and eucalyptus kraft pulps

CERNE

Colodette, Jorge Luiz¹  Andrade, Marcela Freitas¹  Oliveira, Flávia Natalino¹ 

[1] Universidade Federal de Viçosa, Viçosa, Brazil$$

关键词: Delignification;    alkaline leaching;    efficient washing.;   

DOI  :  10.1590/S0104-77602013000300010

来源: Universidade Federal de Lavras-UFLA

【 摘 要 】

In recent decades, the pulp industry has been changing and improving its manufacturing processes in order to enhance production capacity, product quality and environmental performance. The aim of this study was to evaluate the bleachability effect on the efficient washing and alkaline leaching in eucalyptus and pine Kraft pulps using three different bleaching sequences: AD(EP)D, A/D(EP)DP and D_HT(EP)DP. This study was carried out in two stages. In the first part, the optimum conditions for pulp bleaching in order to achieve a brightness of 90% ISO were established. The second step was a comparative study between the pulps that received alkaline leaching and efficient washing with reference pulp (without treatment). The brightness, viscosity, kappa number and HexA in pulp were analyzed. The three sequences studied reached the desired brightness, but the sequence AD(EP)D produced a lower reagent consumption for the same brightness. In the three sequences studied, the efficient washing of the pulp after oxygen delignification has contributed significantly to the removal of dissolved organic and inorganic materials in the pulp and the alkaline leaching decreased significantly the pulp kappa number due to a higher pulp delignification and bleachability.

【 授权许可】

Unknown