An accurate correlation between high-temperature performance and cement content of the high-alumina refractory castables

作者：Xu, Lei^*; Liu, Yang; Chen, Min; Wang, Nan

来源：Ceramics International, 2022, 48(15): 22560-22566.

DOI：10.1016/j.ceramint.2022.04.273

• Low-cement refractory castables
• Sintering mechanism
• Microstructure
• Creep model
• Constitutive relationship

To better guide the composition design of the low-cement high-alumina refractory castables in specific working conditions, in this work, an accurate correlation between their high-temperature performance and cement content was developed and discussed. The results show that both matrix grains and pores show a fine and homogeneous distribution after firing with the cement content in the range of 0-2 wt%. In this range, the liquid distribution is very dispersed, and the matrix is mainly connected by the in situ mullite. Therefore, the maximum working temperature (T0.5) and the creep parameters exhibit a slow linear change with cement content. The liquid amount still shows a linear increase with further increasing the cement content, but it displays a continuous distribution surrounding the matrix grains. This change destroys the direct bonds of mullite and produces many coarse pores, leading to the rapid deformation of the refractories under thermo-mechanical loads. The results suggest that the critical value of cement addition in this refractory is 2 wt% (or ~10 wt% liquid in the matrix), below which the high-temperature performance can be predicted and kept under control.

• 单位
  东北大学