Effect of sintering temperature on microstructure and properties of glass-ceramics synthesized from waste cathode ray tubes funnel glass

• Published in: Journal of Central South University Vol. 28; no. 8; pp. 2320 - 2332
• Main Authors: Lyu, Jian-fang, Jin, Zhe-nan, Ma, Zhi-yuan, Yang, Hong-ying
• Format: Journal Article
• Language: English
• Published: Changsha Central South University 01.08.2021; Springer Nature B.V
• Subjects: Calcium magnesium silicates; Cathode ray tubes; Crystallization; Diopside; Electronic waste; Engineering; Fly ash; Gehlenite; Glass ceramics; Heavy metals; High temperature; Leaching; Metallic Materials; Microstructure; Phase composition; Physical properties; Sintering; Synthesis; Water absorption; Water hardness; 锥玻璃; coal fly ash; 粉煤灰; 铅回收; 烧结温度; funnel glass; lead recovery; sintering temperature; 微晶玻璃; glass-ceramics
• DOI: 10.1007/s11771-021-4772-0
• ISSN: 2095-2899

Waste cathode ray tube (CRT) funnel glass (FG) is an important part in the disposal of electrical and electronic waste (e-waste). A novel approach for efficient lead extraction and glass-ceramics synthesized from waste FG through collaboratively smelting FG with coal fly ash (CFA) is proposed. Glass-ceramics materials with 40 wt%–80 wt% FG additions were produced under sintering temperatures of 900–1000 °C. The microstructure and phase composition of the produced glass-ceramics were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The density, water absorption, Vicker hardness, chemical resistance and heavy metal leaching characteristics of the glass-ceramics were measured. The experimental results indicate that the samples can be crystallized at sintering temperatures of 900–1000 °C. An elevated sintering temperature is favorable for enhancing the degree of crystallization, while the crystallization process is inhibited at excessively high temperatures. Increasing FG addition can lead to the transformation of the main crystalline phase from diopside to gehlenite. Well-crystallized crystals were generated in the specimens with 50 wt%–70 wt% FG additions. The samples with 40 wt%, 50 wt%, 60 wt%, 70 wt%, 80 wt% FG addition exhibit the optimal chemical and physical properties at 975, 925, 950, 925 and 900 °C, respectively. Overall results demonstrate that this study provides a feasible strategy for reliably detoxifying and reusing waste FG and CFA.