Yukon gold mine spill one of two ‘most catastrophic failures’ in heap-leach mining history, expert says

An engineer tasked with reviewing the spill of about two million tonnes of cyanide-soaked ore at a Yukon gold mine says it was one of the two “most catastrophic failures” in the 45-year history of the heap-leaching mining process.Mark Smith says those disasters last year, the other occurring in Turkey, would “define the next 10 or 20 years for heap-leach practices,” in which minerals are extracted from piles of ore by running liquid chemicals through them.