Cindy, Ryotaro Sakai
Environmentally friendly pretreatment of double refractory gold ores (DRGO) to improve gold recovery without emitting pollutant gas is challenging. This study aimed to evaluate a sequential biotreatment using iron-oxidizing microorganisms to decompose sulfides, followed by enzymatic decomposition of carbonaceous matter, with the incorporation of acid washing. The experiment involved testing a real double refractory gold ore from the Syama mines, Mali, which contained 24 g/t of Au and 5.27 wt% carbon. The acid washing process utilizing 1 M HCl for 24 hours between the two bioprocesses was found to significantly enhance gold recovery by cyanidation from 64.4 ± 9.2% to 84.9 ± 0.7%. This improvement is attributed to the chemical alteration of carbonaceous matter that facilitates enzyme accessibility in cell-free spent medium, even though agglomeration was exacerbated by the acid's effect on structural Fe(II) in clay minerals. Sequential treatment of DRGO primarily involves oxidative dissolution of sulfides and degradation of carbonaceous matter prior to gold extraction, though the specifics need to be tailored based on the unique elemental and mineralogical characteristics of the materials.
@article{915b0c5b-74e0-4537-8222-63b958efe987,
title={Significance of Acid Washing after Bioox},
author={Cindy and Ryotaro Sakai},
year={2026},
language={en}
}TY - JOUR TI - Significance of Acid Washing after Bioox AU - Cindy AU - Ryotaro Sakai PY - 2026 LA - en ER -
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