Preparation and characterization of ceramic foams mainly containing extracted titanium residues and silica tailings

Extracted titanium residues (ETR) and silica tailings (ST) were used as the main raw materials, a small amount of coal fly ash (CFA) and foaming agent, SiC, were added, and ceramic foams for building were successfully prepared via one-step firing process of ceramic tiles. Influence of ETR/ST ratio, SiC dosage and sintering temperature on the structure and properties of ceramic foams was systematically examined. Results showed that appropriate ETR addition promoted the quartz melting, which was conducive to the development and homogeneous distribution of bubbles. The porous structure and properties of samples could be controlled via adjusting raw materials and sintering temperature. The thermal conductivity had a strong correlation with bulk density, flexural strength and closed porosity. The flexural strength was more significantly affected by pore structure. When ETR:ST:CFA (mass ratio) = 3:6:1, and foaming agent content was 0.1-0.15 wt%, the pore structure of samples sintered at 1160 degrees C was relatively homogeneous, and the samples had the bulk density of 0.74-0.96 g/cm(3), flexural strength of 3.2-4.9 MPa, water absorption of 0.24-1.78 %, and thermal conductivity of 0.23-0.37 W/mK. The study provides a good disposal strategy for ETR, ST and CFA, and realizes the coupled preparation of all-solid waste based ceramic foams.