METHOD FOR TREATING COLLECTED ASH IN DIGESTING CHEMICAL RECOVERY PROCESS

摘要

PROBLEM TO BE SOLVED: To provide a method for treating collected ash, by which chlorine is removed from collected ash in a digesting chemical recovery process in a pulp production. SOLUTION: A dissolved solution of collected ash in a digesting chemical recovery process and water are alternately passed through a packed bed of an ion exchange resin containing an ion exchange group represented by formula (1) (R1 and R2 are each a 1-3C alkyl group; (m) and (n) are each an integer of 1-4) and a fraction rich in sulfate ion and carbonate ion is separated from a fraction rich in chlorine ion, and both the fractions are recovered separately.