How gold is mined and processed - Mining.com.au

AI desk brief

Gold is mined either by open pit, which accounts for roughly 60–70% of global output and typically exploits 0.5–1.5 g/t ore, or by higher-cost underground methods used for deeper, higher-grade deposits. The article walks through the processing chain from crushing and grinding to cyanide leaching, smelting into doré, and final refinery work to LBMA Good Delivery bars.

It highlights the economics that matter for producers: free-milling ore is easier and cheaper to process, while refractory ore requires pre-treatment such as roasting, pressure oxidation, or bio-oxidation, raising capex and opex. Doré is only semi-pure, typically about 50%–95% gold, before refining to 99.5%+ via Miller or 99.99%+ via Wohlwill.