Molecular dynamics is a method of studying microstructure and properties by calculating and simulating the movement and interaction of molecules. The molecular dynamics simulation method has become an important method for studying the structural and dynamic characteristics of slag systems and can make up for the shortcomings of existing detection methods and experiments. Firstly, this paper analyzes the development process and application fields of molecular dynamics, summarizes the general simulation steps and software algorithms of molecular dynamics simulation methods, and discusses the advantages and disadvantages of the algorithms and the common functions of the software. Secondly, the research status and application progress of molecular dynamics simulation methods in the study of phosphate, silicate, aluminate and aluminosilicate are introduced. On this basis, a method of combining molecular dynamics simulation with laboratory experiments is proposed, which will help obtain more accurate simulation results. This review provides theoretical guidance and a technical framework for the effective analysis of the microstructure of different slag systems via molecular dynamics, so as to finally meet the needs of iron and steel enterprises in producing high-quality steel grades.

In order to make better use of converter dust to achieve effective pre-dephosphorization of molten iron, the influence of the addition ratio of dedusting ash and oxide scale on dephosphorization of molten iron was compared, so as to reveal the reasons for the decrease of dephosphorization rate caused by dust. Through theoretical analysis, XRD, SEM-EDS, Raman and infrared spectroscopy, the influence of mineral phase structure, polymerization degree and phosphorus structure of pre-dephosphorization final slag on pre-dephosphorization was studied. The results show that when the proportion of dedusting ash in the oxidant increases from 0 to 25%, the dephosphorization rate decreases from 50.8% to 38.71%, and the dephosphorization rate increases to 50% after adding fluorite. The increase in the proportion of dedusting ash will lead to the decrease of phosphorus-rich phase and the increase of RO phase and iron-rich phase, which will affect the dephosphorization effect. When the dedusting ash ratio increased from 0% to 25%, the proportion of Q0(Si), Q0(P), Q1(P) and [FeO6]9- structures in the pre-dephosphorization final slag increased, which was beneficial to the diffusion in the slag, but unfavorable to the migration of phosphorus. In addition, by adding fluorite in the experiment with 25% dedusting ash, it was found that the molar fractions of Q1(Si), Q3(Si), Q0(P) and Q2(P) in the pre-dephosphorization final slag increased, and the phosphorus migrating into the silicon-oxygen network structure gradually increased. This study can provide reference for iron and steel enterprises to realize the secondary utilization of dedusting ash.

The CaO–SiO₂–FeO–P₂O₅ slag was measured by Raman spectra, and the changes in the structure and behaviour of phosphorus were analysed under different slag components. The results proved that phosphorus exists in two enrichment behaviours in the slag, which can be judged according to the mole fractions of Q¹(Si), Q²(Si), and Q³(Si). When the content of P₂O₅ increases from 4.5% to 8.5%, the Q⁰(P) intensity changes most significantly. Since the Fe–O bond energy (390.4 kJ mol⁻¹) is weaker than the P–O (410 kJ mol⁻¹) bond energy, the silicon-oxygen network structure will show a behaviour change of depolymerization first and then polymerization. XRD analysis shows that with the increase of P₂O₅ content, different calcium silicate phases are added and decreased in the slag, and the content of a small amount of calcium ferrite phase changes, $\mathrm{S}{\mathrm{i}}_{\mathrm{x}}{\mathrm{O}}_{\mathrm{y}}^{\mathrm{z}-}$ bonds or separates from each other, which is consistent with the change law of Raman analysis.