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.