Chinese researchers have developed a fast, low cost, and environmentally cleaner method for extracting gold from electronic waste, achieving recovery rates that rival industrial mining while avoiding the toxic chemicals traditionally used in recycling. The breakthrough could significantly reshape how e waste is processed worldwide and reduce pressure on conventional gold mining.
The technique was developed by scientists at the Guangzhou Institute of Energy Conversion in collaboration with the South China University of Technology. According to the research team, the method can extract more than 98 percent of gold from discarded mobile phone CPUs and printed circuit boards in less than 20 minutes, all at room temperature.
Electronic waste is one of the fastest growing waste streams globally. The World Health Organization estimates that e waste generation is increasing by about 2.6 million tons every year and could reach more than 80 million tons annually by 2030. While old electronics contain valuable metals such as gold and palladium, existing recovery methods often rely on cyanide or other highly toxic chemicals that pose serious environmental and health risks.
The new approach replaces those reagents with a simple water based solution containing potassium peroxymonosulfate and potassium chloride. Instead of requiring added catalysts, the process relies on what the researchers describe as a self catalytic leaching mechanism. When the solution contacts gold or palladium surfaces, the metals themselves activate the reaction.
On the metal surface, the chemicals generate highly reactive oxidants such as singlet oxygen and hypochlorous acid. These oxidants break down metal atoms, allowing chloride ions to bind with them and dissolve them into solution. From there, the metals can be recovered using standard reduction and purification steps. Laboratory analysis confirmed that the process consistently achieves gold leaching efficiencies above 98.2 percent and palladium recovery rates exceeding 93 percent.
Cost is one of the most striking advantages. The researchers estimate that processing around 10 kilograms of discarded circuit boards yields roughly 1.4 grams of gold at a total cost of about 72 dollars. That equates to roughly 1,455 dollars per ounce, far below current global gold prices, which exceeded 4,400 dollars per ounce in early January.
The environmental benefits are equally significant. The method consumes about 62 percent less energy than conventional techniques and reduces reagent costs by more than 90 percent compared with cyanide based extraction. It also produces far less secondary waste, such as toxic sludge, making disposal and cleanup simpler.
The findings suggest that electronic waste could become a far more attractive and sustainable source of precious metals. If scaled successfully, the process could turn old phones and appliances into a reliable urban mine, easing both environmental damage and supply risks tied to traditional gold extraction.
The study has been published in the journal Angewandte Chemie International Edition.
