Abstract:Recycling of indium (In) from waste liquid crystal displays (LCD) is quite important to solve indium resource shortage and waste LCD pollution. Pyrolysis products of organic matters from waste LCD were used as reductant to recover indium under high temperature/vacuum conditions. Organic matter of waste LCD panels was treated with nitrogen pyrolysis, and parameters were optimized by response surface methodology. Pyrolytic carbon productivity is 28.68% under the optimum conditions including temperature of 350 ℃, heating rate of 2 ℃/min, and N2 flow rate of 0.36 L/min. Indium conversion rate from waste LCD panels is 99.63% under the optimum conditions including temperature of 935 ℃, pressure of 1 Pa, mass fraction of pyrolytic carbon dosage of 40%, and reaction time of 0.5 h. “Waste residue” can be transformed into “reaction raw material (reductant)”, and “organics removal stage” is integrated with “indium recycling stage” in closed-loop management system, as a result, organic pollutants are settled with indium resource recovery at the same time. This program can simplify process route of waste LCD recycling, and provide fundamental basis as well as practical experience for recycling waste LCD environmentally and efficiently.