Onsite CN generation

Gold mines using traditional cyanide-leaching extraction processes will benefit with the launch of a new technology allowing onsite production of sodium cyanide. The technology, developed by Synergen Met Pty Ltd (Brisbane, Australia; www.synergenmet.com), will eliminate a range of hazardous activities associated with the use of the highly toxic cyanide, such as transportation, onsite handling, and maintaining large cyanide inventories. “For the first time, mining companies can produce cyanide on demand and feed directly into existing mills,” says managing director Christopher Dunks. At the heart of the new process is a high-temperature plasma torch, which instead of ammonia (used in existing technologies), uses N2 or simple hydrocarbons, which are more accessible feedstocks that can be produced on-site using off-the-shelf technology. The advantages of using a plasma torch include its high thermal efficiency (up to 90%), its suitability for modulation, and ease of operation, says the company. The company is finalizing testing at its pilot plant in Australia and plans to develop a commercial prototype in 2015, which will be the size of a standard 40-ft shipping container that is readily transportable.