Effect of Silicon Concentration on Melting Behavior of Scraps in Hot Metal

Abstract

To clarify the effects of Si concentration, temperature, and time on melting of the silicon steel, three silicon steels with different Si concentrations were used to conduct an experimental investigation of the melting of scrap cylinders under natural convection. Thermodynamics and kinetics of scrap cylinder melting were revealed and analyzed based on the experimental results. Carbon diffusion between the cylinders and hot metal during melting was modeled using Thermo-Calc 2017b software to evaluate the mass-transfer coefficients. Results showed that a higher Si concentration and lower melting temperature led to slower melting of the silicon steel scrap cylinder. The mass-transfer coefficient of C during the melting decreased with an increase of Si concentration. At 1623 K (1350 °C), the mass-transfer coefficients were 1.322 × 10⁻⁴, 0.436 × 10⁻⁴, and 0.142 × 10⁻⁴ m s⁻¹ for low (0.30 mass pct), medium (1.58 mass pct), and high (3.21 mass pct) Si concentrations in the scrap cylinders, respectively; at a melting temperature of 1723 K (1450 °C), the values of the respective mass-transfer coefficients were 1.370 × 10⁻⁴, 0.613 × 10⁻⁴, and 0.289 × 10⁻⁴ m s⁻¹.