The Influence of Pre-aeration on Cyanide Leaching of a Non-refractory Sulphide Gold and Silver Ore
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Mineral Processing Department, Istanbul Technical University
Mineral Processing Department, ıstanbul Technical University
Beste Aydın   

Mineral Processing Department, Istanbul Technical University, İstanbul Technical University Ayazağa Campus Mining Faculty, Mineral Processing Engineering Departme, 34469 Istanbul, Turkey
Publication date: 2015-03-26
Physicochem. Probl. Miner. Process. 2015;51(2):647–660
The leaching behaviour of a sulphide gold-silver ore was investigated in terms of a relationship between gold and silver extractions and cyanide consumption. 95.0% Au and 88.0% Ag extractions were obtained under the determined conditions as 24h leaching duration, -74 µm particle size, 40% solids ratio, 4 g/L NaCN concentration, and 450 rpm stirring speed with NaCN consumption of 3.35 g/L. Since the NaCN consumption was higher than its industrial applications, in order to decrease the consumption, Pb(NO3)2 and H2O2 additions and aeration using an air pump were tested during leaching. While Pb(NO3)2 addition with aeration caused decreases in metal extractions, the individual or combined additions of H2O2 and aeration could not provide a reduction in cyanide consumption. Therefore, the effect of the pre-aeration followed by cyanidation was tested. Eventually, applying 4h of pre-aeration before a shorter leaching duration of 12h provided 92.0% Au and 90.5% Ag extractions with a lesser NaCN consumption of 2.44 g/L.