Enhancing Sintered Magnesia: Role of ZnO in Densification, Thermal Conductivity, and Corrosion Resistance

This study introduces a method to reduce the thermal conductivity and boost cement clinker corrosion resistance in sintered magnesia using ZnO-modified additives. Solid-solution modified sintered magnesia was prepared at 1700 °C, and the impact of ZnO on the sintering properties, room-temperature strength, thermophysical properties, and corrosion resistance was assessed. ZnO addition enhanced the densification, grain size, and strength of sintered magnesia due to activated sintering from the ZnO and MgO solid-solution reaction at high temperatures. Additionally, ZnO addition improved the thermal stability and thermal shock resistance of sintered magnesia in a high-temperature environment. However, excessive ZnO led to incomplete diffusion, impeding grain growth and degrading the properties of magnesia. The thermal conductivity significantly decreased compared to the unmodified sample, particularly at 1000 °C with 4mol% ZnO addition. Moreover, ZnO improved the corrosion resistance due to increased grain size and densification, with 4mol% ZnO yielding the best results.