Study on Chemical Stripping Characteristics of Polarizer from Waste LCD

The recycling process of waste LCD panel should take into consideration of the removal of the polarizer. With the aid of ultrasonic wave and heating, the polarizer was stripped by alkali solution. The influences of the temperature, concentration of alkali and ultrasonic frequency on the separation of the polarizer were analyzed. And then the glass substrate was extracted by concentrated sulfuric acid and aqua regia successively. The leaching characteristics of indium were also analyzed. The result showed that in the presence of ultrasonic wave and under the temperature range of 50-80 ℃, the polarizer could be separated efficiently from waste LCD panel by sodium hydroxide solution. Besides, the separation of the polarizer only took 37 min with the temperature of 70 ℃, ultrasonic frequency of 45 kHz and NaOH concentration of 0.1 mol/L. The transfer of the indium did not occur during the process of the chemical stripping when the concentration of NaOH was 0.1 and 0.3 mol/L.