Iron oxide and jadeite nucleation in high alumina glass-ceramics prepared from secondary aluminum dross. Issue 15 (1st August 2021)

• Record Type: Journal Article
• Authors: Shen, Hanlin; Liu, Bo; Zhao, Shizhen; Zhang, Junjie; Yuan, Jingshu; Zhang, Yao; Zhang, Shengen
• Is Part Of: Ceramics international. Volume 47:Issue 15(2021)
• Page Start: 21744
• Page End: 21750
• Publication Date: 2021-08-01
• Subjects: Secondary aluminum dross (SAD) -- Glass-ceramics -- Nucleation process -- Iron oxides -- Jadeite; SAD secondary aluminum dross -- AlN aluminum nitride -- SLAS soda-lime-aluminosilicate -- XRF X-ray fluorescence -- Tg glass transition temperature -- FT-IR Fourier-transform infrared spectrometry -- XRD X-ray diffraction -- FETEM field-emission transmission electron microscopy; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.04.189
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Secondary aluminum dross (SAD) is a solid waste of aluminum dross after it is extracted aluminum. Soda-lime-aluminosilicate (SLAS) glass-ceramics with high alumina contents (over 30 wt%) were successfully manufactured from SAD using pyrometallurgy without additional nucleation agents. The nucleation process of SLAS glass was studied, and 670 °C was selected as the nucleation temperature according to differential scanning calorimetry and X-ray diffraction results. Field-emission transmission electron microscopy was applied to study the microstructure of the specimens thermally treated at 670 °C for 3 and 12 h. Nucleation consisted of two parts: iron oxide nucleation and jadeite nucleation. During iron oxide nucleation, when the thermal treatment time increased from 3 to 12 h, the iron oxides first congregated in an amorphous phase and a small amount of metastable crystal; then, the congregated iron oxides crystallized into hematite and magnetite, which acted as crystal nuclei. During jadeite nucleation, the jadeite spontaneously crystallized from the glass matrix after thermal treatment at 670 °C. When the thermal treatment time increased from 3 to 12 h, the size of the jadeite crystals increased from approximately 6 to 12 nm. Jadeite crystals with a diameter of 12 nm acted as crystal nuclei. For glass-ceramics with a high content of aluminum and sodium, jadeite crystals can act as crystal nuclei without additional nucleation agents. Graphical abstract: Image 1