Advancements in improving gold recovery from refractory gold ores/concentrates: a review
Abdelkhalek Barbouchi, Mehdi Louarrat, Mohcine Mikali, Laila Barfoud, Moulay Abdellah El Alaoui-Chrifi, Hakim Faqir, Intissar Benzakour, Rachid Idouhli, Mohy-Eddine Khadiri, J. Benzakour
Abstract
In recent decades, the unsustainable increase in gold mining has led to the progressive depletion of free-milling gold resources. Consequently, the mining industry has shifted its focus towards gold ores with complex or refractory characteristics. The term ‘refractory gold ores’ refers to gold ores characterised by a low extraction yield through cyanidation. Therefore, to improve the gold leaching efficiency, pretreatment techniques are necessary to overcome the refractoriness behaviour. This paper reviews various technologies applied to enhance gold recovery from refractory ores/concentrates, examines the mechanisms of refractory sulphide matrix oxidation and gold liberation, provides updated data on the main operating plants utilising these techniques, and discusses challenges and future prospects in refractory gold processing. The pretreatment techniques reviewed in this paper are bio-oxidation, roasting, pressure oxidation, and ultra-fine grinding.