In this study, the structure, viscosity characteristics, and crystallization behavior of CaO-SiO₂-B₂O₃ based melts were studied combining molecular dynamics (MD) simulation, Fourier transform infrared (FTIR) spectroscopy, rotating viscometer test, and FactSage thermodynamic calculation. The results showed that, in the ternary CaO-SiO₂-B₂O₃ glass system, stable structural units of [SiO₄]⁴⁻ tetrahedral, [BO₃]³⁻ trihedral and [BO₄]⁵⁻ tetrahedral were formed, and the Si-O and B-O structure depolymerize with the basicity increase from 1.15 to 1.25, then the B-O structure become complex with the basicity further increase to 1.35. In fluorine-free mold fluxes, with the basicity increases, the viscosity at 1300 °C increases, the liquidus temperature decreases and then increases, the network structure polymerizes, it indicates that the structural complexity rather than the melting property change plays a predominant role in increasing the viscosity at 1300 °C. Moreover, due to the changes in crystallization phase and solid solution ratio, the viscosity-temperature curve of fluorine-free slag shows the characteristics of alkaline slag and the break temperature increase with the basicity increase. The MD simulation, FTIR experiment, viscosity test, and FactSage calculation results are verified and complemented each other.

In this research, Australian fine iron ore is reduced by pressured carbon monoxide in a fluidized bed. This research aims to obtain the influence law of gas linear velocity, reduction pressure, reduction temperature, particle size, and reduction time on the reduction effect and the economic, convenient, and effective operating parameters, as well as clarify the effect of the pressurized decarbonization of CO, which inhibits the adhesion of fine iron ore particles during the reduction process. The experimental results show that the preferable operating parameters are a linear velocity of 0.8 m/s, reduction pressure of 0.2 MPa, reduction temperature of 1023 K, and particle size of 0.18 mm–0.66 mm. The graphite produced by the carbon precipitation reaction of carbon monoxide hinders the diffusion of iron atoms and avoids the direct contact between the iron atoms, thereby effectively controlling the sticking.

The impact of rare earth treatment on the chemical morphology evolution of non-metallic inclusions in bearing steel under different initial cleanliness conditions was studied through simulation. Thermodynamic calculations indicate that at an oxygen content of 0.001%, the evolution route of inclusions with increasing Ce content was Al₂O₃ → CeAl₁₁O₁₈ + CeAlO₃ → CeAlO₃ + Ce₂O₂S → Ce₂O₂S → Ce₂O₂S + CeS. As the initial oxygen content decreases, the proportion of CeAlO₃ decreases, leading to easier conversion of CeAlO₃ to Ce₂O₂S. Vacuum induction furnace experiments demonstrated that with an oxygen content of 0.001%, an increase in Ce content results in a gradual rise in the proportion of inclusions in steel sized 1~2 μm. In contrast, the proportion of inclusions sized 2~5 μm decreases. Consequently, the overall content of inclusions in steel decreases, along with a reduction in both the number density and average size of inclusions. Introducing bearing steel melt with approximately 0.01% Ce rare earth to bearing steel with initial oxygen contents of 0.0005%, 0.001%, and 0.0015% showed an evolution of inclusions from Ce₂O₂S and CeS to Ce₂O₃, CeAlO₃, etc. The average inclusion size significantly increased from 0.7 μm to 2.16 μm. Morphologically, the transition of inclusions from precipitated to polymerized forms occurred as the initial oxygen content rose. High-temperature laser confocal microscopy experiments demonstrated that inclusions in low cleanliness conditions tend to agglomerate more than those in high cleanliness conditions, contributing to the increase in average size.