| 摘要 |
<p>A mixed prod., consisting of residues obtd. by leaching roasted blend with sulphuric acid, and the prod. obtd. by pptg. iron during purificn. of the leach, is digested with water under pressure. The novelty is that the mixed prod. is treated with water at 250-400 degrees C in a pressure vessel and cooled, followed by sepn. into a liq. and a residue; the liq. contains virtually all the sulphate present in the residue, as soluble Zn-, Cu- and Cd-sulphates, free H2SO4, and all the ammonium sulphate; and the liq. is returned to the zone winning process. The sulphides of Cu and Cd are pref. partially oxidised during the process, esp. by adding MnO2. The process is used in the electrolytic winning of Zn from Zn ores which are first roasted to form oxide and then leached. Improved recovery of Zn and other metals from process residues.</p> |
