首页|(107778)Pretreatment of refractory gold concentrate calcine using ammonium bifuoride and sulfuric acid solution
(107778)Pretreatment of refractory gold concentrate calcine using ammonium bifuoride and sulfuric acid solution
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NSTL
Elsevier
The secondary encapsulation of gold and silver by silicates and Fe-oxide during the roasting oxidation of refractory gold concentrate signifcantly infuence the gold and silver leaching effciency. In this study, a pre-treatment method of refractory gold concentrate calcine using ammonium bifuoride and sulfuric acid solution is proposed. The effects of the NH4HF2 and H2SO4 concentration, pretreatment temperature, and time on the leaching effciency of gold and silver were investigated in detail. The optimum conditions were determined to be NH4HF2 concentration of 1.5 mol/L, H2SO4 concentration of 2 mol/L, pretreatment temperature of 40?C, and duration of 90 min. The leaching effciency of gold and silver reached 97.6 % and 94.8 %, respectively. The pretreatment process of refractory gold concentrate calcine can be expressed with Johnson-Mehl-Avrami (JMA) equation and depends on the diffusion. The pretreated residue was mainly composed of silicates and Fe-oxide minerals. The gold and silver can be exposed to the ore surface by NH4HF2 pretreatment, which helps to improve its cyanide leaching effciency.
NSTL
Elsevier
