Improved Middle-Temperature Strength of Unfired Slide Gate Plate for Continuous Casting of Steel

Abstract

Unfired Al2O3-C slide gate plate refractories bonded with novel silicon-modified phenolic resin (MPR) and additives of Al and Si were prepared. The MPR was synthesized by silica sol via in situ polymerization with lignin–phenolic resin. The results showed that the MPR with corundum owns a better wettability and higher char yield than commercial resin (CR). The middle-temperature mechanical properties such as cold modulus of rupture (CMOR), flexural modulus (E), and force–displacement of Al2O3-C refractory specimens bonded with MPR were improved especially ranging from 673 K to 1073 K (400 °C to 800 °C). The results showed that CMOR of the specimens bonded with MPR coked at 873 K (600 °C) had a considerable improvement with 7.04 MPa in sharp contrast to 3.31 MPa for CR-bonded specimens. It was suggested that the special organic–inorganic network structure of MPR and good wettability with corundum enhanced the bonding strength of Al2O3-C slide gate plate refractories.