In this paper, the preparation of rutile TiO2 powder from titanium slag by microwave-assisted activation roasting followed by hydrochloric acid leaching was investigated. The effects of the additive Na2CO3 on the crystal form, cell, crystallinity, phase transformation, surface functional groups and micro-surface structure of the calcined product were systematically studied using X-ray powder diffraction, Raman spectroscopy, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The results confirmed that the strongest characteristic Raman bands of rutile TiO2 and the weakest FT-IR bands of (CO3)−2 were found when the Na2CO3 mass ratio was 0.4. Accordingly, the crystallinity for the product, namely short rod structure rutile TiO2 powder, reached its peak value of 99.21% with a corresponding average grain size of 43.5 nm. The excessive Na2CO3 was found to be disadvantageous for the crystallinity of the product, since it formed a coverage on the surface of titanium slag which prevented the oxidation reaction for the decomposition of anosovite.
Bibliographical noteFunding Information:
The authors acknowledge the financial support from the National Natural Science Foundation of China (No: U1802255 , 51504110 and 51424114 ), Yunnan Applied Basic Research Project of China (No: 2017FD117 ) and Innovative Research Team (in Science and Technology) in University of Yunnan Province were sincerely acknowledged.
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- Hydrochloric acid
- Microwave roasting
- Phase transformation
- Rutile TiO