PROCESS FOR PRODUCING KRAFT PULP

摘要

A process for producing a kraft pulp, which includes a potassium ion removal step (G) in which an aqueous solution of collected ashes recovered with a dust collector from a combustion gas discharged from a black-liquor combustion step (E) is passed through a bed of a sodium-form cation-exchange resin packing to adsorb and remove potassium ions and a regeneration step (H) in which the cation-exchange resin used in the potassium ion removal step (G) is regenerated with an aqueous caustic soda solution, wherein a fraction rich in sodium sulfate and sodium carbonate and recovered in the potassium ion removal step (G) is circulated to the black-liquor concentration step (D), and a waste caustic soda solution recovered in the regeneration step (H) is reused in the bleaching step (C).