Flash joule heating technology test recovers gold from electronic waste

Gold has been recovered from electronic waste in the latest testing from the company seeking to commercialise a new metals processing technology. Shares in MTM Critical Metals rose 12 per cent in morning trade on Thursday after the company highlighted the latest proof-of-concept testing of its flash joule heating technology. MTM said the exercise recovered up to 70 per cent of the contained gold within e-waste without the use of toxic acids. The company said the process worked by applying direct electrical energy — or “flash” heating — to e-waste in a chlorine gas atmosphere, vaporising the target metals such as gold for efficient separation and collection via metal chlorides. MTM said the process was highly scalable and environmentally friendly, offering a sustainable and energy-efficient alternative to traditional methods of recovering metals from e-waste such as smelting and chemical leaching, which were considered energy-intensive, environmentally harmful and economically inefficient. The company said e-waste was one of the fastest-growing components of solid waste, with more than 60 million tonnes produced annually, of which only about 20 per cent was recycled. MTM said this vast repository contained precious and critical metals such as gold, copper, and palladium, valued at more than $US70 billion in potential recoverable content, and presented a significant opportunity for material reclamation that reduced carbon emissions and minimised toxic by-products. The company said e-waste included discarded electronic devices, which contain a rich concentration of precious metals. “For example, printed circuit boards can contain up 400g/t of gold and 6kg/t of silver, concentrations far higher than in natural ores,” the company said. “However, recovering these metals through traditional methods is energy-intensive, environmentally damaging and expensive. “It is primarily done in smelters/incinerators across China, India, Nigeria, and South-East Asia, often using crude, unregulated methods.” MTM chief executive Michael Walshe said future tests would focus on higher metal content material as it became available. “As global e-waste levels rise and the demand for greener metal production increases, particularly in the face of an acid shortage, FJH presents a cleaner and more efficient alternative to traditional methods,” he said. MTM shares were up 6.1 per cent to 5.2¢ at Thursday’s close.