Pure copper sulphate soln. prodn. - from impure copper salts by a hydrometallurgical treatment

摘要

A pure Cu sulphate soln. is produced from Cu salts contg. chlorides and impurities, or from spent electrolytic solns by using a hydrometallurgical method in which the impure salt is suspended in sulphuric acid. the suspension is treated in an autoclave at a temp. of over 100 degrees C, an increased O partial press., and a pH 3.5-4.5 (3.8-4.0) The basic Cu sulphate ppt. is removed together with Fe2O3, FeAsO4 or CaSO4 from the soln. contg. Zn-, Ce-, Ni-, Mg- and/or Cl ions and the Cu sulphate is then dissolved in dil. sulphuric acid and sepd. from the impurities which remain undissolved. The impure material may be a Cu salt contg. Fe, Zn, Co, Ni, As, CaO, MgO and/or Cl or a spent electrolyte from the production of electrolytic Cu in which case the spent electrolyte is mixed with an inorganic basic substance such as ZnO, CuO or CaO before prepg. the suspension. Process is simple and more economical as it is not necessary to deal with a large volume of organic phase as is usual with the liquid-liquid extn. method, or with further treatment stages including the purificn. of the leaching soln.