Catalytic oxidn. of aq. (bi)sulphite soln. to (bi)sulphate - using ferric (and ferrous) ions as catalyst, avoiding toxicity problems

摘要

In the catalytic oxidn. of aq. (bi)sulphite solns. to (bi)sulphate solns. with (gases contg.) O2 at 0-250, pref. 40-120 degrees C, esp. between room temp. and 100 degrees C, oxidn. is carried out in the presence of Fe(III) and pref. also Fe(II) ions in a concn. of 0.001-100 ppm w.r.t. the entire soln. The Fe(III):Fe (II) ratio pref. is 2-8:1 esp. 6:1 and the oxidn. pref. is carried out at pressures below 50 pref. 10 atmos. Used in the treatment of waste liquors from the chemical ind. Both Fe(II) and Fe(III) ions are partic. active catalysts and are useful hwn Cu and Co salts cannot be used because of their toxicity.