Method for producing fully oxidized white liquor

摘要

A method for white liquor oxidation in a kraft mill utilizes a two-stage selective oxidation system in which the first stage is operated to remove sulfide while the second stage is operated to oxidize a significant fraction of the remaining oxidizable sulfur compounds to sulfate. The resulting selectively oxidized white liquor products are used as alkali sources for various process steps in the mill. Optionally, white liquor can be oxidized in a single stage to convert a significant fraction of the oxidizable sulfur compounds to sulfate. Methods for controlling the selective oxidation process are disclosed.