METHOD FOR CONTROLLING CHEMICAL BALANCE OF PULP MILL Russian patent published in 2022 - IPC D21C9/14 D21C11/06 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for optimizing a chemical balance in a sulfate pulp mill that produces at least cellulose bleached with chlorine dioxide and has a device for chlorine dioxide production using at least chlorate, methanol and sulfuric acid to produce chlorine dioxide. The method includes at least following stages: a) gases from a system of concentrated non-condensing gases of the mill are burned to form gas containing sulfur dioxide, which is processed to produce concentrated sulfuric acid, and b) crude methanol from technological processes of the mill is purified to produce methanol, and c) by-streams containing sodium compounds and/or sulfur compounds obtained as a result of technological processes of the mill are used as make-up chemicals, in the production of chlorine dioxide, sulfuric acid is used obtained at the stage a), and methanol purified at the stage b), so that sulfuric acid is concentrated commercial sulfuric acid, and at the stage c), sesquisulfate or sodium sulfate obtained in the production of chlorine dioxide is used.

EFFECT: obtaining a method for controlling a chemical balance of a pulp mill.

6 cl, 1 dwg