Process for the preparation of cooking liquors having high sulphidity for sulphate pulp cooking

Abstract From the Canadian patent

An improvement is provided in a process for preparing under reducing , conditions, cooking liquors for sulphate pulp cooking. The black liquor which is formed in the cooking, process is fed, after evaporation completely or partly to a reactor operating at increased, temperature. The increased temperature is obtained by energy which is supplied from an, external heat source and/or release of energy from the black liquor thereby , to form a melt, of sodium sulphide. The melt then is withdrawn to be further processed to cooking liquor. The melt, and the whole or part of at least one of sulphur-containing sulphur-, and sodium-, containing materials which are present in the pulp mill …