The effect of freezing and drying method on the structure and properties of large-format high-density oxide refractories

The article discusses an approach to improving the sintering technology for large-sized high-density oxide refractories by adding a freezing stage after molding and modifying the drying stage, using corundum compositions as an example. The article examines the impact of the initial mixture characteristics, freezing conditions, and drying conditions on the structure and physical and mechanical properties of the finished refractory products. It is found that the inclusion of the freezing stage results in the production of samples with higher apparent density and reduced open porosity compared to samples obtained without freezing. The most effective mode is recognized as a sharp freezing followed by drying under convective conditions. Moreover, the proposed method contributes to the acceleration of the turnover of forms and, accordingly, to the increase in efficiency and productivity of the entire process.