Immobilization of High-Leaded Cathode Ray Tube Glass in Fired Clay Bricks by Recycling

Abstract

End-of-life cathode ray tubes (CRTs) have become global problem in the pool of waste electrical and electronics owing to higher concentration of lead (Pb) and this needs urgent management in an ecofriendly manner. In this study, spent CRT glass was incorporated in clay to make burnt bricks for construction. Samples of CRT glass were collected from technicians’ workshops, manually dismantled, pulverized, milled and sieved into three particles sizes (PS), namely; 0.6mm ≤1.0mm, ≤2.0mm. The metallic composition was determined with Inductive Coupled Plasma- Optical Emission Spectrometric technique (ICP-OES). Each PS was mixed with clay at percentages ranging from 0% as control to 15% CRT and moulded using dry compression technique, dried and fired in furnace at 800 0C. Mechanical properties of fired bricks products were assessed including water absorption, linear shrinkage and compressive strength. The 4wt% CRT-clay composition for ≤0.6mm PS exhibited highest strength with low linear shrinkage and medium water absorption and was selected as optimum composition. Lead (Pb) leachability from fired CRT-glass/clay from the three particle sizes using TCLP and SPLP were within permissible limit of 5.0mg/L set by US-EPA. The total recoverable lead (Pb) from optimum test composition was 96mg/L or 96,000 mg/kg that exceeded the permissible limit. From the findings, it can be shown that the optimum composition of less than 0.6mm particle size is of good quality, durable and environmentally safe bricks that can be used for building construction works.