Preparation of Zr ⁴⁺ doped calcium hexaaluminate with improved slag penetration resistance

Aiming to improve the density of calcium hexaaluminate (CA 6 ), Zr 4+ doped CA 6 with the structural formula of CaAl 11.73 ◊ 0.25 Zr 0.02 O 18.41 ◊ 0 . 59 (CaAl 11.73 Zr 0.02 O 18.41 ) was successfully synthesized at 1600℃ for 4 h in air. The effect of Zr 4+ doping on the crystal structure of CA 6 was investigated using first principle calculation, structure refinement in combination with experimental characterization. The results suggest that Zr 4+ prefers to substitute the Al 3+ at Al3 site, which can increase the lattice parameter of c ‐axis and the amount of Al vacancies. The average thickness of Zr 4+ doped CA 6 is increased by approximate 36% in comparison with the pure one. In addition, molecular dynamics (MD) simulation indicates that Zr 4+ doping can reduce the wettability of CA 6 to slag to some extent. The reaction test method was carried out and it shows that CA 6 with Zr 4+ doping possesses better slag penetration resistance. Based on this, the reaction mechanism is also discussed.