| Zirconic ramming mix used for glass kiln has been prepared from Zircon AZS-bonded (Al2O3-ZrO2-SiO2).The influences of AZS addition and silica sol-alumina multi-binder on physico-mechanic performance and corrosion resistance of zircon ramming mix have been systematically studied by using SEM, EDAX, XRD, DTA and examination of physico-mechanic performance of zircon ramming mix. The mechanism for the corrosion resistance enhancement of the material caused by the AZS addition and the multi-binder has also been discussed preliminarily.The principal and secondary crystalline phases, matrix composition , porosity , sintering treatment of the ramming mix are major factors affecting the corrosition resistance to liquid-glass.The sample of zirconic ramming mix with different amounts of 30% AZS powders were sintered at 1300℃.The results show that the compressive strength and the porosity of the mix obtained reached 155 Mpa and 9.0 % respectively with 30% AZS in mass ratio and at sintering temperature of 1300℃ . Moreover the effects of AZS as the additional refractory powders on zircon ramming mix significantly reduce the sintering temperature and obviously improves the porosity and the corrosion resistance to liquid-glass. The structure of the mix, characterized by close bond between particle and matrix, coexistence of well-distributed mullite as well, results in the good comprehensive properties of the ramming mix.The binders of H3PO4 aluminous cement and silica sol have been studied. The experimental results indicate that the binder of silica sol with Al2O3 not only improves workability and sinterability but also enhances corrosion resistance of the mix,owing to the formation of mullite in the binder.Sintering zircon is very difficult . Using Al2O3 or MgO powders as sintering additives affects the sintering temperature, porosity and crystalline phases, which can improve the corrosion resistance of the material .The amounts of Al2O3<10 % and MgO<2 % are optimum .
|
PDF Full Text Request