Composition optimization and high-temperature characteristics of fluorine-free CaO-SiO ₂ -FeO-B ₂ O ₃ -MnO dephosphorization slag

Abstract

The effect of the proportion of each component on the viscosity and melting temperature of fluorinefree CaO-SiO 2 -FeO-B 2 O 3 -MnO dephosphorization slag (DS) was simulated by FactSage software. A reasonable composition control interval and molten pool temperature were obtained. The orthogonal experiment led to the optimal ratio of the dephosphorization agent, which was further verified by laboratory dephosphorization experiments. The experimental results showed that with the increase in FeO, B 2 O 3 , and MnO content, the melting temperature and viscosity of DS decreased. With the increase in basicity, the melting temperature increased but the viscosity decreased. B 2 O 3 had the greatest effect on melting temperature, while FeO had the greatest effect on viscosity. At 1400°C, the optimum ratio of DS is 9 wt% B 2 O 3 , 10 wt% MnO, 45 wt% FeO, and the basicity is 4.0. The dephosphorization experiment carried at the optimum ratio resulted in the maximum dephosphorization degree of 93%.