RECOVERY OF NOBLE METALS BY LIXIVIATION WITH THIOUREA CONTROLLED ACIDIC SOLUTION

摘要

A leaching process for the recovery of gold from a gold containing ore is described in which a gold ore is lixiviated with an acid (pH 0.5-2.0) solution containing 1-15 g/l thiourea in the presence of an oxidising agent and a reducing agent. The concentrations of thiourea and of formamidine disulphide are determined for example by a high pressure liquid chromatographic method, and an amount of oxidising agent or reducing agent being added to maintain the molar ratio of thiourea: formamidine sulphide to between about 2:1 and 5:1.