Open    Access



Treatment of a Polysulphide Ore by Ammoniacal Thiosulfate Solutions and Ion Flotation for Gold Recovery




Author(s)

Sebastián Gámez and Ernesto de la Torre

Full-Text PDF XML     1222 Views

DOI:10.17265/2328-2193/2015.02.002

Ammoniacal thiosulfate solutions with cupric ions have proved to be more successful than cyanidation in handling complex ores like carbonaceous and cuprous minerals. That’s why cyanidation and ammoniacal thiosulfate leaching was performed at 33% of solids concentration in order to compare the efficiency of both techniques. Cyanidation delivered a gold recovery of 80.6% at 24 hours of agitation, whereas ammoniacal thiosulfate leaching achieved an 80.9% of gold recovery in only one hour of agitation. Then, the ammoniacal thiosulfate solutions obtained were submitted to five gold recovery techniques (carbon adsorption, cementation, adsorption on carbon impregnated with metallic copper, ion flotation and electrolysis) in order to determine which one of them was the most effective technique. Ion flotation proved to be the best technique due to its gold recovery of 84%. In addition, this technique only required trioctyl methyl ammonium chloride (Aliquat) and FloMin F-121 in a 0.1% concentration inside the solution. The small amounts of the flotation reagents allow the flotation concentrate to be treated by electrolysis. It was performed with 1.5 V during three hours and the resulting gold recovery was 82% in the cathode zone.

Ammoniacal thiosulfate leaching, ion flotation, electrolysis.