EXTENDED DELIGNIFICATION - A STATUS-REPORT

For non-chlorine bleaching to be successful technologically and econom ically, the residual lignin 'load' in a chemical pulp entering a bleac h plant should be minimized. Increasingly, chemistries such as oxygen/ alkali delignification and kraft pulping itself play important roles. This paper addresses the key technical aspects of extended delignifica tion in kraft pulping: what driving forces have pushed this developmen t forward, what chemical principles underlie it, and how the technolog y is applied. The information comes from mill operations, supplemented by leading-edge research and development. A status report on extended delignification installations worldwide is included.