Preparation and physical properties of silicalite composites sintered from purple soil and shale residue

Abstract

We prepare several silicalite composite materials in which foamed ceramics and glass ceramics were connected together without any interlayer. Purple soil and shale residue were used as raw materials to prepare the foamed ceramics that constituted the thermal insulation layer in the silicalite composite materials. The glass ceramics were prepared from waste glass added with 0, 5, 10, 15, 20 and 25 wt% SiO2, which formed the decorative layer in the composite materials. The bonding mechanism of the thermal insulation layer and the decorative layer, and the influence of SiO2 content on the properties of glass ceramics and composite materials were investigated via XRF, XRD, SEM, EDS, etc. The results indicated that the best properties of glass ceramics and composite materials could be achieved at the addition of 20 wt% SiO2. The bulk density, bending strength and coefficient of thermal expansion of the glass ceramics were 2.775 ± 0.015 g cm-3, 58.5 ± 1.2 MPa and (5.65 ± 0.2) × 10-6 m m-1 K-1, respectively. The shear strength and tensile strength of the composite material reached 0.877 ± 0.025 MPa and 0.798 ± 0.02 MPa, respectively.