SILVER AND GOLD LEACHING AND RECOVERY PROCESS WITH ELECTRO-OXIDISED THIOUREA SOLUTIONS.

摘要

The invention relates to the mining and mineral-processing industry. More particularly, the invention relates to a dissolution composition, which enables the use of thiourea. In particular, the invention relates to a method of forming a dissolution, which improves both the speed of extracting silver and gold from minerals and other materials containing same, thereby improving the stability of the thiourea in the lixiviant solution, and the direct electrorecovery of the metals from said solution. The invention makes use of a leaching solution, which is subjected to prior or simultaneous controlled electrooxidation in order to produce formamidine disulphide (FADS) which acts as an oxidising agent for the mineral phases containing gold and silver. In the preferred embodiment of the invention, the FADS forms in a proportion of between 10 and 30 % of the total thiourea contained in the solution and the electrodeposition of the metals is performed in the same cell (cathodic compartment) as that in which the FADS forms (anodic compartment).