Study On Preparation And Properties Of The High Temperature Low-expansion Glaze On Burnt Stove Door Cordierite Brick

The cordierite brick has good thermal shock resistance which meets the need of burnt stove door. But the corrosion of harmful substance and the mechanical damage of carbon bed scraper reduce the physical performance of the cordierite brick. In this paper, one kind of high temperature low-expansion Glaze was developed which suits for the cordierite brick of burnt stove door. The glaze can protect the cordierite brick of burnt stove door against the carbon deposition as well as corrosion.In this article, the phase of the MgO-Al₂O₃-SiO₂ system and the Li2O-MgO-A12O3-SiO2 system were analyzed. Two glaze's foundation chemical composition was established by unifying the theoretical calculation and the experiment. The glaze can be sintered together with the cordierite brick at 1350℃. The fast-sinter-low-cool sintering system was set through the differential thermal analysis and the XRD.Study the influence of content of MgO,K₂O,Na₂O,Li₂O and nucleator (ZrO₂) on the glaze's fusing characteristic,crystallization and thermal-expansion coefficient Through the theoretical calculation,the XRD and the linear expansion analysis. When the MgO and Li2O content are higher, the glaze's fusing characteristic is good and the coefficient of thermal-expansion is lower, so that the glaze layer is smooth without cracks. When the K2O or Na2O content is higher, the glaze have bad fusing characteristic and the coefficient of thermal-expansion is higher, so that the glaze layer is easy crack. The nucleator (ZrO₂) promotes crystallization of glaze.The glaze thermal shock experiment test indicates that the glaze is suit for the cordierite brick. The glaze fills the blowhole on the cordierite surface, the glaze prevents the harmful substance permeate into cordierite brick with its high compactness, so that it can protect the brick against corrosion. The smooth glaze surface prevents carbon deposition also.