To increase the utilization of V-Ti-Magnetite ore in the burden of a blast furnace, we investigated replacing CaO with MgO. The high fraction of TiO₂-bearing raw materials leads to a super-high TiO₂ content in the blast furnace slag, typically above 30 wt pct, which affects normal blast furnace operation. The present study focuses on the sulfide capacity of slag containing a super-high TiO₂ content. The effects of TiO₂ content and the ratio of MgO to CaO (M/C) on the sulfide capacity of slag were examined using a gas-slag equilibrium method. In the CaO-SiO₂-TiO₂-MgO-Al₂O₃ slag system, as the content of TiO₂ in the slag increased from 20 to 34 wt pct, the sulfide capacity decreased from 6.25 × 10⁻⁵ to 2.86 × 10⁻⁵. Above 30 wt pct TiO₂, the influence of TiO₂ content on the sulfide capacity became negligible. Increasing the (M/C) ratio induced a non-monotonic trend in the sulfide capacity, which first increased and then decreased. Thermodynamic and structural analyses were employed to characterize the experimental results. Thermodynamically, decreasing the CaO activity reduced the free oxygen in the slag with increasing TiO₂ content. Furthermore, an increase of titanium suboxide slowed the reduction of the sulfide capacity. Mass substitution mainly influenced the availability of free oxygen in the slag, and then the sulfide stability and oxygen concentration worked together, resulting in a non-monotonic sulfide capacity when MgO was substituted for CaO. In addition, the sulfide capacity was dependent on the effect of both the quaternary molar basicity and the binary molar basicity. Finally, the structural analysis revealed that for a super-high TiO₂ content in the slag, both the structure of Ti and the depolymerization reaction of Ti had an extremely important effect on desulfurization.

为了提高高炉炉料中钒钛磁铁矿的利用率，我们研究了用 MgO 代替 CaO。高比例的含 TiO ₂原材料导致高炉炉渣中的超高 TiO ₂含量，通常高于 30 wt pct，这会影响正常的高炉操作。本研究的重点是含有超高 TiO ₂含量的炉渣的硫化能力。采用气-渣平衡法研究了TiO ₂含量和MgO与CaO的比例( M / C )对渣硫化物容量的影响。在 CaO-SiO ₂ -TiO ₂ -MgO-Al ₂ O ₃在渣体系中，随着渣中TiO ₂含量从20 wt pct增加到34 wt pct，硫化物容量从6.25×10 ^-5降低到2.86×10 ^-5。超过 30 wt pct TiO ₂，TiO ₂含量对硫化物容量的影响变得可以忽略不计。增加 ( M / C ) 比值导致硫化物容量呈非单调趋势，先增加后减少。热力学和结构分析被用来表征实验结果。在热力学上，随着 TiO _{2 的}增加，降低 CaO 活性会减少渣中的游离氧内容。此外，低氧化钛的增加减缓了硫化物容量的降低。质量取代主要影响渣中游离氧的可用性，然后硫化物稳定性和氧浓度共同作用，导致当 MgO 取代 CaO 时硫化物容量非单调。此外，硫化物容量取决于四元摩尔碱度和二元摩尔碱度的影响。最后，结构分析表明，对于炉渣中超高的TiO ₂含量，Ti的结构和Ti的解聚反应对脱硫具有极其重要的影响。