Flinders university researchers have developed a more sustainable, safer method to recover gold from ore and electronic waste. The technique promises to reduce toxic waste from mining efforts by extracting high purity gold from recycled components in printed circuit boards or waste computers.
Published in the journal Nature Sustainability, the new technique uses low cost trichloroisocyanuric acid to extract the gold. Trichloroisocyanuric acid is a benign compound commonly used for water sanitation and disinfection and once activated by salt water, is capable of dissolving gold.
Once dissolved by the reagent, the gold is selectively bound by a sulfur-rich polymer that was also developed by the team. The selectivity of the polymer allows for gold recovery even in challenging or complex matrices.
“The study featured many innovations including a new and recyclable leaching reagent derived from a compound used to disinfect water,” said Justin Chalker, who leads the Chalker Lab at Flinders University’s College of Science and Engineering. “The team also developed an entirely new way to make the polymer sorbent, or the material that binds the gold after extraction into water, using light to initiate the key reaction.”
“The newly developed gold sorbent is made using a sustainable approach in which UV light is used to make the sulfur-rich polymer,” added ARC DECRA Fellow Dr Nicholls. “Then, recycling the polymer after the gold has been recovered further increases the green credentials of this method.”
“We dived into a mound of e-waste and climbed out with a block of gold! I hope this research inspires impactful solutions to pressing global challenges,” concluded Dr Harshal Patel, a Flinders University postdoctoral research associate.