Patent ID: 6544384
Filing Date: 2003-04-08
Classification: D21C

Abstract:
A method of treating wood chips to produce chemical pulp, comprising the steps of sequentially continuously:(a) steaming the chips to remove air from them and to heat them to a temperature of about 80-100Â° C.; (b) soaking the chips in an alkaline liquid having an alkaline concentration of about 0.75 moles per liter or less, at a temperature between about 80-100Â° C., for a time of 30 minutes to 72 hours to produce dissolved organics; (c) displacing out at least part of the dissolved organics after step (b) using white liquor, diluted white liquor, bleach plant effluent, or pulp washing effluent; and (d) cooking the material from step (c) to a kappa number below 25.