Recovery of indium from In2O3 and liquid crystal display powder via a chloride volatilization process using polyvinyl chloride

Indium (In) was recovered from indium oxide (In2O3) and liquid crystal display (LCD) powder via a chloride volatilization process using polyvinyl chloride (PVC) as the chlorination agent. The recovery of In from In2O3 increased with an increasing molar Cl/In ratio in N2 and air atmospheres. The degree of In recovery at a Cl/In molar ratio of 11 and a temperature of 350 °C was 98.7% and 96.6%, for N2 and air, respectively. The In recovery also increased notably with increasing temperature in N2 atmosphere. In both atmospheres, the In recovery increased with an increasing degradation temperature of PVC. However, the In recovery from LCD powder was lower than that from In2O3. For LCD powder, the degree of In recovery at a Cl/In molar ratio of 11 and a temperature of 350 °C was 66.7% and 54.1%, for N2 and air, respectively.