Evaluation of lead recovery efficiency from waste CRT funnel glass by chlorinating volatilization process.

ABSTRACT

The current study was carried out to develop a novel process, namely chloride volatilization procedure for lead recovery from waste cathode ray tube (CRT) funnel glass. In the recovery system, the glass powder was first compressed into cylindrical pellet homogeneously with chlorinating agents, and then subjected to thermal treatment for solid-phase reaction. In this case, lead could be easily released from the silicon oxide network of the glass and it was recovered in the form of PbCl2. It was found that CaCl2 was the most effective chlorinating agent, and the optimum operation temperature, holding time and system pressure were 1000 °C, 2 h, 600 ± 50 Pa, respectively. The evaporated PbCl2could be easily recovered by a cooling device. The evaporation ratio of lead from waste CRT was 99.1% and the purity of the recovered PbCl2product was 97.0%. The reaction routes and lead recovery mechanisms of the process were identified. This study provides an efficient and practical process for waste CRT funnel glass detoxification and recycling.