Recycling Of Gan, A Refractory Ewaste Material: Understanding The Chemical Thermodynamics

South Korea is a major producer of light-emitting diode (LED) material, contributing 31% of total LED demand worldwide, and also a major consumer of electronic devices. During manufacturing and after end of life (EOL) of the consumer electronics, significant amount of GaN-bearing waste is being generated. As the Republic of Korea depends upon the import of all mineral commodities, under the national policy of securing a stable supply, much attention has been paid to the notion of urban mining. The stringent international environmental directive for recycling of waste electrical and electronic equipment (WEEE), United Nations Environment Programme (UNEP) E-Waste Management goal, restriction of the use of hazardous substances in EEE (RoHS), and extended producer responsibility (EPR) have made recycling an important responsibility. Recovery of the gallium from GaN-bearing waste can be a promising feasible option; simultaneously from the waste, the wealth can be generated. As GaN is a refractory material, which is hard to leach in the recovery process, hence, needs a chemical pretreatment. In this study, thermodynamics of GaN oxidation and oxidative roasting using Na2CO3 has been studied. Thermodynamic feasibility for leaching of oxidized GaN either through acidic leaching or through alkali leaching has been explored.