The effect of 15 wt%Al2O3 addition on the equilibrium phase relations of CaO–SiO2–TiO2 system at 1400 °C in air

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2021-09-01
Major/Subject
Mcode
Degree programme
Language
en
Pages
7
24802-24808
Series
Ceramics International, Volume 47, issue 17
Abstract
The combined processing of industrial wastes of titania-bearing slags with coal fly ash is an important part of the circular economy. In the present work, the effect of Al2O3 on the 1400 °C liquidus isotherms of the perovskite, rutile and tridymite primary phase fields in the CaO–SiO2–TiO2–Al2O3 system has been determined by employing a high-temperature equilibration-quenching technique, followed by X-ray Photoelectron Spectroscopy and Scanning Electron Microscopy-Energy Dispersive X-ray Spectrometry. Titanium was confirmed to be stable as TiO2 in the present equilibria. The equilibrium solid phases of perovskite CaO·TiO2, rutile TiO2 and tridymite SiO2 were confirmed to be coexisting with the liquid oxide phase. The comparison of the addition of 0–15 wt% Al2O3 was beneficial for expanding the primary phase field of perovskite to lower TiO2 concentrations. Comparisons of the experimental 1400 °C isotherm with the predictions using FactSage and MTDATA databases confirmed some differences to the present experimental data, thus demonstrating the direction for updating the present thermodynamic titania-bearing oxide databases.
Description
Funding Information: This study received financial support from Aalto University . The authors would also like to acknowledge the financial support from the China Postdoctoral Science Foundation [Grant number 2020TQ0059 , 2020M680967 ], the Fundamental Research Funds for the Central Universities [N2125010] and China Scholarship Council [Grant number 201706370096 , 201806370217 ]. Publisher Copyright: © 2021 Elsevier Ltd and Techna Group S.r.l.
Keywords
AlO, FactSage, Perovskite, Phase diagram, Titania-bearing slag, Urban mining
Other note
Citation
Wan, X, Shi, J, Qiu, Y, Chen, M, Li, J, Liu, C, Taskinen, P & Jokilaakso, A 2021, ' The effect of 15 wt%Al 2 O 3 addition on the equilibrium phase relations of CaO–SiO 2 –TiO 2 system at 1400 °C in air ', Ceramics International, vol. 47, no. 17, pp. 24802-24808 . https://doi.org/10.1016/j.ceramint.2021.05.205