Copper recovery from oxidised metal residues - by lixiviation with ammoniacal solution, removal of sulphates and acid extraction of copper@

摘要

The process, for extracting copper from metallurgical residues, e.g. from smelting furnaces, consists of (I) lixiviation at 15-100, preferably 25 degrees C for 0.5-4, preferably 1 hour, with an aqueous solution of ammonium hydroxide, carbonate and/or chloride; (II) removal of sulphates from the extract by addition of Ca ions; (III) extraction of copper from the solution using acid organic agents in immiscible solvent at 15-45 degrees C with dwell time of 5-20 minutes; (IV) re-extraction of copper with an aqueous acid solution, preferably spent electrolyte; and (V) purification of the lixiviation solution from (III), regenerated by neutralisation of acid produced in copper extraction, with the ammonium from the metal complex for return to (I).