Lead recovery from cathode ray tube funnel glass with mechanical activation

Abstract

In the disposal of electronic waste, cathode ray tube (CRT) funnel glass remains an urgent environmental problem because of its high lead content. This research developed mechanical activation as a pretreatment process, and it proved to be an effective method for extracting lead from CRT funnel glass. The effects of mechanical activation on the structural changes of CRT funnel glass were investigated using X-ray diffraction (XRD), particle size analysis, specific surface area (SSA), and a scanning electron microscope (SEM). Nitric acid leaching behaviors of the activated CRT funnel glass were studied by varying several parameters: leaching time, liquid-to-solid ratio, acid concentration, and heating temperature, as well as various conditions of activation. The lead recovery rate was observed to increase rapidly, particularly with increases in activation time and leaching temperature, but to vary relatively less under other experimental parameters. Under the optimal leaching conditions, the lead recovery rate for funnel glass activated for 2 hr at the rotational speed of 500 rpm (by ball mill) reached 92.5%, compared with 1.2% from the unactivated sample.Implications: CRT funnel glass containing lead has become a serious environmental problem facing the whole world. In order to dispose of CRT funnel glass, some technologies have been developed. However, these technologies are associated with higher operation and maintenance costs. In this study, mechanical activation was introduced to change the physicochemical properties of CRT funnel glass, which can transform the glass into an easily dissolved one. Under atmospheric pressure leaching conditions, good recovery rate for lead can be achieved and the residue has wide uses. The process can be applied to treat other leaded glass or leadcontaining wastes.

Innovative Application of Mechanical Activation for Rare Earth Elements Recovering: Process Optimization and Mechanism Exploration

“…The apparent reaction order for the leaching process was 0.67 ± 0.06. The results indicate that the mechanical activation process could cause destruction of the crystal structure of the phosphors, which could be the reason for the sharp decrease in apparent activation energy, leading to the transformation of the rate-controlling step from chemical reaction to diffusion, and making the REE leaching much easier 41 42 .…”

TSP, PM10 and health risk assessment for heavy metals (Cr, Ni, Cu, Zn, Cd, Pb) in the ambience of the production line for waste cathode ray tube recycling

“…Iron and Nickel could be separated from anti-explosive and Nickel net, respectively. Thermal shock and laser cutting methods are adopted to separate panel glass from the funnel [7], and various methods were applied to recover metallic lead from the funnel glass, such as the vacuum-aided carbon thermal reduction method [8] and the mechanical activation method for extracting lead [9]. It is of great importance for the improvement of human living environment and resources recycling.…”

Detoxification effect of chlorination procedure on waste lead glass

“…Previous studies focused on the enhanced leaching of lead silicate glasses so as to improve the lead extraction efficiency by breaking the glass's structure [7][8][9][10][11][12]. Furthermore, various utilizations of the CRT glasses were studied at the same time.…”