This process uses the oxygen to oxidize the sodium sulfide
into sodium thiosulfate (partial oxidation) and sodium sulfate
(total oxidation). The reactions of this process are exothermic,
making possible the recuperation of the heat generated.
The use of white liquor oxidation
at the pulp production offers some advantages:
It is an economically interesting
alkali source;
Supports the Kraft mill chemical
closure and enables better control of system's metal level;
Makes easier to maintain the plant's
chemical balance.