Corrosion Behavior of Lightweight MgO in High Basicity Tundish Slag
Chong Wei Tan, Yu Liu, Guangqiang Li, Cheng Yuan, Yufeng Tian, Yongshun Zou, Ao Huang
Abstract
Demand for energy saving in steelmaking process, lightweight refractories have attracted great attentions for the excellent thermal insulation. Herein, the corrosion behavior of the lightweight magnesia in the high basicity tundish slag is explored, and compared with that of fused magnesia. The results show that the impurities in the fused magnesia cause more dissolution of magnesia into slag after 60 min. Different from fused magnesia, the penetration layer is found in the lightweight magnesia, where the intercrystalline CaZrO 3 –ZrO 2 phases are dissolved by the slag. The micropores in the lightweight magnesia provide passages for slag infiltration, but also accelerate the supersaturation of slag in refractory and impede the mass transfer. Furthermore, the residual CaZrO 3 –ZrO 2 phases in transition layer hinder the further slag infiltration. After 60 min holding, the MgO content in molten slag contacted with lightweight magnesia is lower, implying that the lightweight magnesia is the promising refractory for tundish lining.