A review of indium recycling methods from LCD screen wastes

Abstract

Indium, one of the important rare metals, has drawn more and more attention due to its semiconductor and optoelectronic performance. The by-products of zinc refineries are used as the primary mineral resources for the commercial production of indium. Indium contents of these products usually vary in a range of 100÷200 g/t. However, as a main secondary source of indium, LCDs waste contains much higher contents of indium than that in mineral ores. LCDs waste may contain up to 1,400 g/t In (equivalent to 0.7 g/m2). The indium recovery process from LCD screen wastes undergoes three stages: dismantling LCD screens; separation of indium-containing ITO glass, and recovery of indium metal. This paper presents the characteristics of the indium recovery process from LCD screen wastes and the main techniques used in each stage of technology. From there, a few suitable specific indium recycling processes are proposed for the conditions in Vietnam