Highly efficient extraction of indium from zinc oxide dust by ultrasonic-enhanced leaching process

Leaching is of great importance to extract indium in metallurgy. However, contemporary approaches for leaching indium, which enable indium dissolve into acid solution as ions, usually face challenges such as complex process, prolonged duration, harsh acidity, and poor efficiency. Herein, we present a novel approach for the highly efficient extraction of indium (In) from zinc oxide dust (ZOD) utilizing ultrasonic-enhanced two-stage leaching. The leaching efficiency of indium has reached 98.1 % under relatively mild acid (180 g/L) and very short period (120 min, nearly half time of other methods). That mainly attributed to the ultrasonic cavitation effect, which facilitates solute dispersion, enhances wetting, and promotes mass transfer across liquid-solid interface, thus synergistically reinforcing leaching process. Importantly, our strategy being compatible with traditional processes, offers a promising pathway for indium recovery featured by simplicity, high efficiency, and costeffectiveness under ultrasonic conditions, which broadens the ultrasonic technology applications in metallurgy.