Use of oxidized white liquor in a kraft mill digester

摘要

Pulp is produced from wood or other lignocellulosic material by an improved kraft process in which the white liquor is introduced into the digester in at least two streams. A portion of the white liquor is used in an initial stage of the pulping process. Another portion of the white liquor is oxidized to convert reduced sulfur compounds in the white liquor to sodium thiosulfate and/or sodium sulfate, and this liquor is used during a later stage of the process. The benefits of using split sulfidity white liquor to produce pulp are realized by using a combination of white liquor and oxidized white liquor in the pulping process. <IMAGE>