Chloride removal from copper or zinc sulphate soln. - by pptn. with cuprous cpd. under acid conditions

摘要

Removal of Cl ions to a max. content of 60 mg/l, from solns. contg. Cu and/or Zn sulphate, esp. for electrolysis involves treatment with Cu(I) oxide (I) or Cu (I) salts which are soluble in sulphate solns. at a pH of max. 3. The soln. is treated with at least twice, pref. 2.5-3 times the stoichiometric amt. of the Cu(I) cpd. for the formation of Cu(I) chloride and the soln. is kept at a temp. between the crystallisation temp. and 50 degrees C, pref. 40 degrees C and pH 3.0, pref. 1.5, with sulphuric acid (II). The reaction time for chloride pptn. is very short, i.e. ca 2-4 min. In an example, Cu sulphate soln. contg. 80g/l Cu and 1 g/l Cl was treated with moist (I) at pH 1.5 and 40 degrees C. Using 150,200 or 300 stoichiometric % of (I) the Cl content after 2 min. was 220,49 or 55 mg/l respectively.