Immobilization of Lead in Cathode Ray Tube Funnel Glass with Beneficial Use of Red Mud for Potential Application in Ceramic Industry

Abstract

The soon-to-become obsolete cathode ray tube (CRT) funnel glass can cause a potential hazard to the environment because of its high level of lead content. Red mud is a hazardous material due to its high alkalinity. Reusing them for the ceramic industry by immobilization into a chemically resistant matrix is an alternative strategy. In this study, the potential use of red mud to immobilize the lead content in the CRT funnel glass was investigated. Results show that the lead in the CRT funnel glass was successfully incorporated into a chemically durable crystalline magnetoplumbite (PbFe12O19). The X-ray diffraction (XRD) results indicated that magnetoplumbite was the major lead-bearing crystalline phase in the products. The loading capacity of CRT funnel glass reached up to 25 wt % in the mixture. Rietveld quantitative XRD analysis showed that Pb could be effectively incorporated into magnetoplumbite at a moderate temperature (900 °C). Results from a prolonged toxicity characteristic leaching procedure demonstrated that the leached lead concentration from the product was 3 orders of magnitude lower than that from the CRT funnel glass. Both the effective Pb incorporation and the substantial reduction of leached Pb after sintering with red mud suggested a promising method for the sustainable management of CRTs and red mud. Copyright © 2018 American Chemical Society.