Ethylenediaminetriacetic acid and salts thereof as chelating agents in pulp bleaching

摘要

A process for metal ion chelation in pulps. Extraction and removal of detrimental metal ions, preferentially manganese, iron and copper, prior to delignification and bleaching is carried out on pulp, preferably kraft pulp, using ethylenediaminetriacetic acid or ethylenediaminetriacetic acid salts as the chelating agent. Suitable salts include alkaline earth metal, alkali metal, ammonium and amine.