Abstract Na2O, CaF2, B2O3 are commonly used fluxes in metallurgical slags. These fluxes reduce the viscosity of slags are related to changing the melt structures. In this study, molecular dynamics simulation was used to analyze the main effects of Na2O, CaF2, and B2O3 respectively on the melt structure of the traditional CaO–SiO2 metallurgical slags. The results showed that since Na+ ions have only one charge, and the electrostatic restraint between the multi-charged ions and the depolymerized [SiO4]4− tetrahedrons cannot occur on Na+ ions. The overall mobility of the particles in the melt structure is improved with the replacement of Ca2+ with Na+. Therefore, the fluidity of CaO–SiO2–Na2O slags is stronger than that of CaO–SiO2, and the viscosity is reduced. F− ions mainly bond with Ca2+ ions to form complexes. The resulting Ca–F structures destroy the electrostatic restraint between Ca2+ ions and depolymerized depolymerized [SiO4]4− tetrahedrons in the Ca–O structures, and the fluidity of CaO–SiO2–CaF2 slags are improved. The effect of B2O3 on the melt structure of CaO–SiO2 is related to the basicity. In this study, when the value of basicity is 1.87, the addition of B2O3 increases the degree of polymerization of the CaO–SiO2 melt structure, and the viscosity may increases.

中文翻译：

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熔体结构与粘度的关系：不同熔剂对CaO-SiO2渣的影响

摘要 Na2O、CaF2、B2O3是冶金渣中常用的助熔剂。这些助熔剂降低熔渣的粘度与改变熔体结构有关。本研究通过分子动力学模拟分析了Na2O、CaF2和B2O3分别对传统CaO-SiO2冶金渣熔体结构的主要影响。结果表明，由于Na+离子只有一个电荷，多电荷离子与解聚的[SiO4]4-四面体之间的静电约束不会发生在Na+离子上。用 Na+ 代替 Ca2+ 改善了熔体结构中颗粒的整体流动性。因此，CaO-SiO2-Na2O渣的流动性强于CaO-SiO2，粘度降低。F-离子主要与Ca2+离子结合形成络合物。由此产生的Ca-F结构破坏了Ca2+离子与Ca-O结构中解聚解聚的[SiO4]4-四面体之间的静电约束，提高了CaO-SiO2-CaF2渣的流动性。B2O3 对 CaO-SiO2 熔体结构的影响与碱度有关。在本研究中，当碱度值为 1.87 时，B2O3 的加入提高了 CaO-SiO2 熔体结构的聚合度，粘度可能会增加。