Patent ID: 6585880
Filing Date: 2003-07-01
Classification: D21C

Abstract:
A method for recovering at least one chemical in a process for producing a kraft pulp, said method comprisingelectrolyzing an alkaline solution containing Na2S by an electrolytic oxidation method, said alkaline solution flowing in said process, forming a liquid containing a polysulfide sulfur in an amount of 6 g/l or more at an anode side, adding said liquid to said process before a chip has a maximum temperature, optionally causticizing said liquid before adding said liquid to said process, adding an NaOH solution formed at a cathode side to at least one stage among after said chip has said maximum temperature through a final bleaching stage, and recovering and reusing at chemicals obtained from at least one stage added said NaOH, which chemicals among a plurality of chemicals discharged from a cooking step through a final bleaching stage, or mixture thereof.