Lead recovery from waste CRT funnel glass by mechanochemical reaction with reductive Al powder

The safe disposal of waste cathode ray tubes (CRTs) has always been a serious problem due to the stable microstructure of toxic lead (Pb) located in glass. Thousands of researches have been trying to explore envi-ronmental and efficient ways to dispose of waste CRTs. To recycle lead from waste CRT funnel glass effectively, a mechanochemical reduction method has been developed in this research. Aluminum was used as a reductant, and the hydrochloric acid solution was used in the leaching process to separate lead from the solution. After mechanochemical ball milling with aluminum, lead ion in CRT funnel glass was transferred into nano-sized element lead. Lead recovery from CRT funnel glass increased significantly as compared to non-activated lea-ded glass. Approximately 40 % of lead was leached after mechanical activation without aluminum, while over 96 % of lead in the CRT funnel glass could be recovered after mechanochemical reduction with aluminum. Lead chloride (PbCl2) can be recycled from the leaching solution after cooling crystallization. Nano-sized Pb formation and the structural changes of leaded CRT funnel glass by mechanochemical reduction process contributed to obvious improvement in lead recovery. This research provided a high-efficiency and feasible approach for recovering lead in form of PbCl2 crystal from leaded glass.

Automated summary

This research developed a mechanochemical reduction method to effectively recover lead from waste CRT funnel glass and improve the lead recovery rate. By mechanochemical ball milling with aluminum, lead ion in CRT funnel glass was transformed into nano-sized element lead, which was then separated from the solution using hydrochloric acid leaching. The formation of nano-sized Pb and the structural changes of leaded CRT funnel glass during the mechanochemical reduction process contributed to an significant improvement in lead recovery.