Recycling

Biography

Biography: Fu-Shen Zhang

Abstract

Cathode ray-tube (CRT) is an important device mainly used as video display component in television and computer. It is rapidly replaced by advanced displays such as liquid crystal display and plasma display, resulting in a huge number of waste CRTs. CRT funnel glass generally contains high level of PbO, which is classified as hazardous waste. This type of waste may contaminate our living environment due to improper treatment. In the present study, a novel process for lead nanopowder synthesis from this type of glass was developed by combining vacuum carbon-thermal reduction and inert-gas consolidation procedures. The key merit of the process was to evaporate lead out of the glass to obtain harmless glass powder and synchronously produce lead nanoparticles. In the synthesis process, lead oxide in the funnel glass was firstly reduced to elemental lead, and evaporated rapidly in vacuum circumstance, then quenched and formed nano-size particles on the surface of the cooling device. Experimental results showed that temperature，pressure and argon gas flow rate were the major parameters controlling lead evaporation ratio and the morphology of lead nanoparticles. Toxicity characteristic leaching procedure results showed that lead leaching from the residue glass met the USEPA threshold. Accordingly, this study developed a practical and environmental-friendly process for detoxification and reclamation of waste lead-containing glass.