University of Oulu

Gupta, A. K., Aula, M., Sreenivasan, H., Mäkelä, P., Huttula, M., & Fabritius, T. (2022). Study of Synthetic Titania Slags Demonstrating Characteristics Similar to High Titania Ilmenite Slag. Minerals, 12(3), 386.

Study of synthetic titania slags demonstrating characteristics similar to high titania ilmenite slag

Saved in:
Author: Gupta, Avishek Kumar1; Aula, Matti1; Sreenivasan, Harisankar2;
Organizations: 1Process Metallurgy Research Unit, Faculty of Technology, University of Oulu, FI-90014 Oulu, Finland
2Fibre and Particle Engineering Research Unit, University of Oulu, FI-90014 Oulu, Finland
3Metso Outotec Research Centre, FI-28330 Pori, Finland
4Nano and Molecular Systems Research Unit, University of Oulu, FI-90014 Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 4.5 MB)
Persistent link:
Language: English
Published: Multidisciplinary Digital Publishing Institute, 2022
Publish Date: 2022-06-28


The upgradation of the ilmenite ore, using a pyrometallurgy method, is performed using a carbothermic reduction of the ilmenite. A high titania slag is obtained which is used as a feedstock for the TiO₂ pigment production. The slag is cooled after tapping in big molds and can take ten days to cool. This cooling method has remained the same since the inception of ilmenite smelting and recently rapid cooling through granulation has been utilized. The work presented in this paper focuses on the microstructural study of the slags that were prepared using different techniques and cooled at different cooling rates. Various analytical techniques, such as X-ray powder diffraction (XRD), scanning electron microscopy (SEM), inductively coupled plasma-optical emission spectroscopy (ICP-OES), and X-ray photoelectron spectroscopy (XPS) were used to exhibit the similarity of these synthetic slags to the properties of high titania ilmenite slag. The slag consisted mostly of pseudo-brookite phase with a M₃O₅ stoichiometry and smaller amounts of silicate and rutile phase. A glassy phase of silica was observed and most of the impurities were found to be present in the silicate phase. These silica phases were observed to be separate from the pseudo-brookite phase and along the phase boundaries. Micro-cracking of the slag surface, which is the characteristic of the M₃O₅ phase formed in the ilmenite slag, were observed under the SEM analysis. The XPS analysis revealed that faster cooling does result in lower amount of oxidation but the difference in the TiO₂ and Ti₂O₃ composition can have larger impact on oxidation than the cooling speed.

see all

Series: Minerals
ISSN: 2075-163X
ISSN-E: 2075-163X
ISSN-L: 2075-163X
Volume: 12
Issue: 3
Article number: 386
DOI: 10.3390/min12030386
Type of Publication: A1 Journal article – refereed
Field of Science: 216 Materials engineering
Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 713606 under the I4Future doctoral programme—Imaging for the Future: Novel Imaging and Characterization Methods in Bio, Medical, and Environmental Research and Technology Innovations.
EU Grant Number: (713606) I4FUTURE - Novel Imaging and Characterisation Methods in Bio, Medical, and Environmental Research and Technology Innovations
Copyright information: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (