Lead Evaporation from CRT Glass and Nanocrystallization Mechanism in the High-temperature Self-propagating Process

Abstract

Lead evaporation and recovery of nanoparticle materials from waste cathode-ray tube (CRT) glass using the self-propagating high-temperature synthesis (SHS) method was investigated. The reaction temperature and combustion velocity of the mixture of Fe2O3-Mg-CRT in the SHS process were studied in detail. Then the lead extraction ratio, phase compositions as well as the micromorphology of extracted PbO nanoparticles were examined. The thermodynamics of lead evaporation and nanocrystallization mechanism were also analyzed. It can be found that the SHS reaction temperature and combustion velocity decrease with increasing CRT glass content, and the addition of CRT glass as a diluent can be used to control the SHS lead extraction behavior to obtain PbO nanoparticles with good desperation and morphology. With 40wt% CRT glass addition, about 93% of lead can be recovered from CRT glass as nano-sized PbO with high purity. The collected PbO nanoparticles are almost spherical in shape with particle sizes ranging from 40 nm to 50 nm, which are mainly from the volatilization and rapid condensation during the SHS process. The study indicates a novel method to recycle and reuse waste CRT glass.