Aqueous chlorine dioxide prodn. - by contacting a chlorine dioxide-chlorine gas mixt. with an aqueous chlorine dioxide-chlorine solution in several stages

摘要

In a first stage the gas mixt. composed of ClO2, Cl and air is contacted in countercurrent to the aq. soln., which is satd. w.r.t Cl, or unsatd. w.r.t. clO2, at a temp. the gas mixt. This produces an aq. soln. of ClO2 and Cl of high ClO2 conc,. The gas mixt. having a smaller concn. of ClO2 but higher Cl content is contacted in stage 2 in countercurrent to water to dissolve the total ClO2, and a proportion of Cl. The gas mixt. contg. Cl, but no ClO2, and aq. soln. of ClO2 and Cl is taken from the contacting zone and heated to a temp. the gas mixt. and up to the satn point of Cl. The hot soln. is fed to stage 1 to serve as aq. soln. for the treatment of the original gas mixt.