Why is sodium cyanide still indispensable for gold extraction despite its extreme toxicity?

Why is sodium cyanide still indispensable for gold extraction despite its extreme toxicity?
Sodium cyanide remains the workhorse reagent in gold mining because no viable substitute matches its efficiency and cost. The chemistry is straightforward: cyanide ions form stable complexes with gold, dissolving it from ore as Na[Au(CN)2], which is then recovered via zinc displacement. Real-world consumption is intense—one Inner Mongolian gold producer using 2,000+ tonnes of sodium cyanide monthly to produce 5.1 tonnes of gold annually, implying roughly 4.7 tonnes of NaCN per kilogram of gold. While environmental and safety concerns persist, especially after incidents like the Tianjin warehouse explosion, the mining sector's dependence is unlikely to break soon. Alternatives are either less effective or economically uncompetitive, so demand from gold mining remains the primary price anchor for sodium cyanide in China.