Metallurgy

Pilot-Scale Aluminothermic Silicon Production

M. Zhu, H. Philipson, K. Blandhol et al.

Abstract

NTNU, Elkem, and SINTEF researchers demonstrate pilot-scale aluminothermic silica reduction using secondary aluminum materials to produce silicon-rich alloys and alumina-rich slag.

Pilot-Scale Aluminothermic Silicon Production

Conventional silicon production relies on carbon-based reduction of silica at high temperatures, generating direct CO₂ emissions.

Researchers from NTNU, Elkem Technology, and SINTEF investigated the SisAl process, an alternative method using aluminum-based reductants and secondary industrial materials.

Key Research Findings

  • Pilot-scale production of silicon-rich alloys containing approximately 70–75 wt% silicon.

  • Generation of calcium-aluminate-rich slag with potential for further alumina recovery.

  • Evaluation of aluminum blocks, scrap, and dross as reductants.

  • Demonstration of process control through feedstock ratios and operating conditions.

Industrial Significance

The study establishes pilot-scale technical evidence for alternative silicon production and industrial material circularity.

Additional refining, environmental assessment, and commercial-scale validation are required for advanced silicon applications.

Original publication: Zhu, M., Philipson, H., Blandhol, K., et al. (2024). Pilot-Scale Aluminothermic Production of Silicon Alloy and Alumina-Rich Slag.

Journal: ACS Sustainable Chemistry & Engineering, 12(40), 14795–14809.

Source: https://doi.org/10.1021/acssuschemeng.4c05326

Independent academic research. Presented for technical reference; results are not SilexTech experimental achievements.