Effect of B2O3 on the properties of ferronickel melt and mineral wool

Abstract To utilize both ferronickel slag and its sensible heat, the melting and viscosity-temperature behaviors of the B2O3 modified slags were studied first. Results show that the initial melting temperature reduces from 1612 K (1339 °C) to 1534 K (1261 °C), and the complete melting temperatures decreases from 1744 K (1471 °C) to 1696 K (1423 °C) with the increase of B2O3 from 3 to 9 wt%. However, the temperature span of the viscosity ranging in 0.5–2.5 Pa s increases from 10 K (°C) to 39 K (°C) with increasing B2O3. Then, the characterizations of the slag fibers prepared by the modified slags suggest that the addition of B2O3 decreases the mean diameter of the slag fibers from 5.6 ± 0.45 μm to 3.4 ± 0.27 μm, whereas increases their tensile strength from 1724 ± 80 MPa to 2114 ± 136 MPa. Moreover, both the glass transition temperature (Tg) and crystallization temperature (Tc) are delayed by the addition of B2O3 since boron works as network former in the slag melt structure.