Fabrication of highly isotropic porous alumina refractory clinkers consisting of platelets using a gelatin-sol

Abstract

Porous alumina bodies are expected to find application as refractory materials to reduce energy consumption during the manufacture of inorganic products. The porosity of such bodies can be efficiently increased by using alumina platelets to form a so-called "house-ofcards" structure. This technique was employed in the present study, together with a gelatin-sol (as binder) and freeze-drying. The porosity, compressive strength, and thermal conductivity of a porous alumina body made in this manner and heat-treated at 1600°C were 80.2%, 1.7 MPa, and 0.94 W/m −1 •K −1 , respectively. These physicochemical properties would allow this alumina to be used as a thermal insulation refractory clinker material.

Preparation of Magnesia Insulation Materials by Calcination of Walnut Shell Powder by Silica Sol Impregnation

“…Wei et al prepared porous alumina ceramics by impregnating rice husks with the zirconia sol. Compared with the sample prepared without any impregnated rice husk, the internal pore shape of the sample has changed significantly, and its intensity has been significantly improved [15]; Yang et al added the zirconia sol as an inorganic bond to prepare the mullite fiber ceramics, whose bulk density is 0.45-0.66 g/cm 3 and compression strength is 0.62-3.34 MPa [16]; Muto et al prepared an aluminium oxide thermal insulation material by using the hydrogel as the binding agent based on the house-of-cards structure as a template, and its thermal conductivity is 0.94 W/m K (1600°C), while the compression strength is 1.7 MPa [17].…”