Recycling of Secondary Aluminium Production Waste in Processing of Mullite Based Refractory Ceramics

Abstract

This work describes the studies to reuse secondary aluminium production waste (SAPW) derived from aluminium casting processes in the fabrication of mullite-based refractory ceramics. SAPW was characterized by using particle size analysis, X-ray diraction (XRD), scanning electron microscopy (SEM) and X-ray uorescence (XRF). Secondary aluminium production waste (SAPW), quartz and Grolleg kaolin were mixed stoichiometrically, according to chemical formula of mullite (3Al2O3 · 2SiO2) by ball milling. Cylindrical samples were consolidated by uniaxial dry pressing and sintered at dierent temperatures (up to 1350• C). The phase and microstructural evolution, water absorption, bulk density, mechanical properties of sintered samples were investigated and refractory ceramics based on mullite were obtained.

Effect of talc and titania on the microstructure and mechanical properties of alumina ceramics

“…The addition of MgO and talc may decrease the formation temperature of Al 2 TiO 5 although the phase diagram indicates the formation temperature above 1280°C . The exothermic peak F at 1450°C is caused by the mullitization reaction . Thus, the sintering temperatures for fabricating Al 2 O 3 ceramics with A 3 S 2 in this study are designed to be 1400‐1500°C.…”

“…29 The exothermic peak F at 1450°C is caused by the mullitization reaction. 30,31 Thus, the sintering temperatures for fabricating Al 2 O 3 ceramics with A 3 S 2 in this study are designed to be 1400-1500°C.…”

Effect of mechanical activation on mullite formation in an alumina-silica ceramics system at lower temperature

“…This in turn increases their reactivity and hence reduces the mullitization temperature. According to Kirsever et al (2015), when the samples were sintered at 1,200°C for 1 h, the quartz and alumina were noted to be the major phases. The mullite phase appeared as the sample was sintered at 1,300°C for 1 h. When sintering temperatures were elevated to between 1,300 and 1,450°C, the intensity increased and the much sharper X-ray reactions…”

“…The mullitization temperature is of interest in this present study. Kirsever et al (2015) showed the XRD patterns of sintered samples heated at 1,200, 1,250, 1,300, 1,350, 1,400 and 1,450°C for 1 h. When the samples were sintered at 1,200°C for 1 h, the quartz and alumina have been noted to be the major phases. The mullite phase appeared as the sample was sintered at 1,300°C for 1 h. When sintering temperatures were elevated to between 1,300 and 1,450°C, the intensity increased and the much sharper X-ray reactions of mullite were observed.…”