Ion-exchange technologies for the minimum effluent kraft mill - Authors make a case for an innovative system

New ion-exchange technology has recently been developed to address a number of key issues relating to kraft mill closure. One process removes sulphuri c acid from the sodium sulphate by-product from chlorine dioxide generators . The other two processes remove chloride and metal, to prevent buildup in a closed kraft cycle. A discussion of the relevant issues is followed by a description of the ion exchange processes themselves, including typical per formance data and field experience.