A study on ceramic sintering preparation process and properties with the addition of silicon carbide foaming agent

Foamed ceramics are widely used in construction as a building material. This article used potassium feldspar tailings as the primary raw material and added a silicon carbide (SiC) foaming agent to prepare samples through a sintering process. The impact of three factors − SiC content, sintering temperature and heat preservation time − on sample properties (such as bulk density and water absorption rate) was analyzed using a single-factor variable method. It was found that the increase in SiC content, sintering temperature, and heat preservation time increased pores inside the sample, thereby leading to a higher water absorption rate, lower compressive strength and higher mass loss rate, i.e., decreased sample performance. Overall, the optimal sintering process parameters were as follows: a SiC content of 1.0 wt%, a sintering temperature of 1,250℃ and a heat preservation time of 30 minutes. Under these conditions, the obtained sample had a bulk density of 0.54 g/cm3, a water absorption rate of 13.45%, a compressive strength of 4.75 MPa, a thermal conductivity of 0.06 W/(m·K) and an acid resistance mass loss of 1.21%, exhibiting the optimal performance. The experimental results provide appropriate SiC content and sintering parameters that can be applied in practice to obtain higher-performance foam ceramics.