Materials separation from waste liquid crystal displays using combined physical methods

With the liquid crystal displays (LCDs) being widely used in televisions, notebooks, and mobile phones, etc., large quantities of LCDs are entering into their end-of-life stage for treatment. If not treated properly, a loss of resources and undesirable impacts on the environment and human health can occur. In order to treat the waste LCDs in an efficient and environmentally friendly way, a combined process of physical methods was proposed to separate and recover materials from waste LCDs in the present study. On the basis of primary disassembly, two key processes (including liquid crystals removal and the recovery of polarizer and glass) were studied. Liquid crystals were removed from the panel glass by dissolving in isopropyl alcohol solution (16.7 vol.%) assisted with ultrasound. Recovery of polarizer and glass was achieved through mechanical crushing and gravity concentration. Results show that approximately 100 wt.% of liquid crystals were removed after dissolving for 45 min at 60ºC. Up to 79.7 wt.% of polarizer was separated from glass and its average content in the recovered product was 90.3 wt.%.