Numerical Simulations of the Impact of CaO/Al<sub>2</sub>O<sub>3</sub> on the Structure and Crystallization Behavior of Red Mud

oleh: Lei Xing, Zhi-Hui Li, Pei-Pei Du, Yue Long

Format: Article
Diterbitkan: MDPI AG 2024-05-01

Deskripsi

The problem of large stockpiles of red mud needs to be solved, and the use of red mud to prepare inorganic fibers is a new way of applying red mud on a large scale. The role of CaO/Al<sub>2</sub>O<sub>3</sub> in the melting point and melt structure of red mud was investigated by molecular dynamics simulations and thermodynamic calculations. Liquid phase line temperatures for different CaO/Al<sub>2</sub>O<sub>3</sub> systems were calculated using the Factsage program. The radial distribution function and the type of oxygen bonding were used to characterize the effect of different CaO/Al<sub>2</sub>O<sub>3</sub> on the structure of the red mud melt. The melting point of MgAl<sub>2</sub>O<sub>4</sub> is lower than that of CaTiO<sub>3</sub> due to the fact that the type of oxygen bonding in MgAl<sub>2</sub>O<sub>4</sub> is predominantly bridging oxygen bonds. When the red mud system has a low SiO<sub>2</sub> content and CaO/Al<sub>2</sub>O<sub>3</sub> is between 0.3 and 3.9, the melting point temperature increases significantly, which is not conducive to the fibrillation of the red mud melt.