Effect of rice husk powder as a binder on mechanical and thermal properties of ZrO2 hollow-fiber refractory bricks

Abstract

ZrO2 hollow-fiber bricks are a type of thermal-insulation product with low density and thermal conductivity. ZrO2 hollow-fiber bricks made with Zr-sol as the high-temperature binder have poor strength; therefore, it is necessary to find a binder that can overcome these challenges. Rice husk contains a large concentration of amorphous SiO2, because of which it can be used as a binder for ZrO2 hollow-fiber bricks. After treatment, rice husk powder was added to the ZrO2 hollow fibers as a high-temperature binder, which formed ZrO2 hollow-fiber bricks after sintering. The densities and thermal conductivities of these ZrO2 bricks prepared at 1300 °C were unaffected by the rice husk-derived binder, while the compressive strengths increased by 285% compared with that of the Zr-sol binder.