The team of JIANG Bao uses a process based on extraction by strong air oxidation at the micro-interface, using micro-nano bubbles to release active oxygen when they burst. Using this procedure, the gold in minerals is rapidly oxidized to water-soluble gold ions, and the gold ore leaching rate is above 95%. After gold is adsorbed, the aqueous solution is recycled to achieve zero discharge. The process was already scaled-up to the ton-level. Using this cyanide-free gold extraction system, the cost of environmental protection treatment can be reduced from 1,000 to 15-25 CN¥ per ton. Energy consumption is about 30% lower compared to the traditional process, and leaching time is reduced to 1-2 days.
CAS news release, January 19, 2021
CAS Shanghai Institute of Organic Chemistry develops cyanide-free clean gold extraction technology