Effect of the Slag Composition on the Sustainable Silicothermic Synthesis Process of Titanium Silicides
Abstract
1. Introduction
2. Experimental
3. Results
3.1. Effect of Different Slag/Silicon Ratios
3.2. Effect of Slag Compositions
3.3. Kinetic Analysis
4. Conclusions
- (1)
- TiSi2 can be synthesized across a broad range of slag compositions, but the formation of bulk TiSi2 requires a longer reaction time to facilitate the agglomeration of the intermetallic phases. A slag/silicon mass ratio increase from 1 to 4 can promote the production rate of TiSi2. However, rs no greater than 3 is suggested for the complete extraction of titanium sources from the slag and to avoid excessive dilution of silicon.
- (2)
- Ti5Si3 forms in a later stage of the reaction via further interaction of TiSi2 with the slag. Its formation is kinetically slower due to both the high melting point of TiSi2 and the diffusion barrier created by the development of a continuous Ti5Si3 network within the slag. The influence of slag viscosity, basicity, and melting point was found to be negligible under the current experimental conditions. The formation of the Ti5Si3 network may limit further reaction progression, and future work could explore mitigation strategies such as decreasing the slag viscosity, applying a supergravity field, and introducing low-melting point additives into the product.
- (3)
- From a kinetics perspective, the TiO2 content in the slag is suggested to be below 30 mol% to optimize reaction efficiency. The optimal reaction rate constant identified in this study is above 1 × 10−4 s−1 under the experimental conditions.
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Process | Raw Materials | Products | Ref. |
---|---|---|---|
Combustion synthesis | Pellet composed of Ti, Si powders | Ti5Si3, TiSi2 | [5,6] |
Mechanical alloying | Ti and Si powders | TixSi100−x, Ti5Si3 | [7] |
Melting | Ti and Si, or TiO2 + SiO2 + Mg | Ti14Si86, Ti16Si84, Ti21Si79 | [8,9] |
Electrochemical reduction | TiO2 and SiO2 containing pellet | Ti5Si3 | [10,11] |
Electrosilicothermic method | TiO2-slag and Si | Ti-Si ferroalloy | [12] |
No. | Contents/Mass% | Slag/Si in Mass Ratio rs | Melting Point /°C | Density /g·cm−3 | ||
---|---|---|---|---|---|---|
TiO2 | CaO | SiO2 | ||||
1 | 40 | 32 | 28 | 1 | ~1400 | ~3.35 |
2 | 40 | 32 | 28 | 2 | ||
3 | 40 | 32 | 28 | 3 | ||
4 | 40 | 32 | 28 | 4 | ||
5 | 83 | 17 | 0 | 3 | 1460 | ~4.01 |
6 | 60 | 24 | 16 | 3 | ~1380 | ~3.65 |
7 | 26.2 | 36.8 | 37 | 3 | 1348 | ~3.14 |
8 | 20 | 40 | 40 | 3 | ~1370 | ~3.05 |
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Yu, Z.; Dang, J.; Chen, Z. Effect of the Slag Composition on the Sustainable Silicothermic Synthesis Process of Titanium Silicides. Sustainability 2025, 17, 3994. https://doi.org/10.3390/su17093994
Yu Z, Dang J, Chen Z. Effect of the Slag Composition on the Sustainable Silicothermic Synthesis Process of Titanium Silicides. Sustainability. 2025; 17(9):3994. https://doi.org/10.3390/su17093994
Chicago/Turabian StyleYu, Ziyou, Jie Dang, and Zhiyuan Chen. 2025. "Effect of the Slag Composition on the Sustainable Silicothermic Synthesis Process of Titanium Silicides" Sustainability 17, no. 9: 3994. https://doi.org/10.3390/su17093994
APA StyleYu, Z., Dang, J., & Chen, Z. (2025). Effect of the Slag Composition on the Sustainable Silicothermic Synthesis Process of Titanium Silicides. Sustainability, 17(9), 3994. https://doi.org/10.3390/su17093994