LAUSR

Gallium (indium)-containing dust as a hazardous waste generated from light-emitting diode (LED) epitaxial wafer manufacturing attracts worldwide attention because of both resources and environmental importance. Oxidative roasting combined with acidic leaching is frequently utilized to recover the corresponding metals from such dust, while the recovery rate is usually low because of the rather inert physicochemical properties of gallium compounds. Simultaneously, the selectivity of leaching is low, which results in complex separation or purification is required in order to obtain the required product (e.g., metallic gallium, Ga(OH)3). In this research, it is demonstrated that the selectivity of leaching can be achieved via properly controlling the physicochemical properties of the leaching solution and the leaching conditions. The leaching rate of gallium can reach 90.01% through optimizing the effects of different parameters, including leaching reagent concentration, solid-to-liquid ratio, reaction temper...