Effect of MnO content on slag structure and properties under different basicity conditions: A molecular dynamics study.

• The influence of MnO content more than or less than 4 wt% on the structure and properties of slag is different. • High bacisity and the MnO content exceeds 4 wt% enhanced depolymerization of aluminosilicate structure by MnO. • The micro complexity of slag system is positively correlated with the macro viscosity. • Low basicity and high MnO promote lower liquidus temperature of slag. In this paper, molecular dynamics (MD) is used to simulate the local structural order, oxygen bond network and transportation characteristics of the slag system under different basicity, and the influence of MnO on the properties such as viscosity, liquidus temperature and enthalpy was studied. MnO or basicity will not affect the bond length and the coordination number of Si-O, but the coordination number of Al-O is slightly reduced. The conversion rate of BO and TOs to NBO or FO is accelerated when CaO/SiO 2 ratio is 1.2 and MnO exceeds 4 wt%. It indicates that an increase in MnO content at high basicity will make the depolymerization of the slag structure more obvious. The total self-diffusion coefficient of each atoms increases with the increase of basicity and MnO, while the viscosity of slag showed an opposite trend. The enthalpy of the slag increases linearly and the conditions of low basicity and high MnO are beneficial for keeping a low liquidus temperature and realizing the stable and smooth of the blast furnace. [ABSTRACT FROM AUTHOR]