Investigation on High-Temperature Creep Properties of High-Alumina Bauxite

摘要

In this article, we study the high temperature creep properties of Al_2O_3~78% high-alumina bauxite (the mass fraction of Al_2O_3in the raw ore is about 78%). The results indicate that the Al_2O_3~78% high-alumina bauxite at 1100°C/50h, 1200°C/50h and 1300°C/50h creep ratio is -0.266%, -1.589% and -4.088% respectively. X-ray diffraction shows that the main crystal phase of Al_2O_3~78% high-alumina bauxite is corundum phase after high temperature sintered. At 1100 °C and 1200 °C, TiO_2 is an independent existence as the rutile phase, the aluminum titanate phase is formed by the reaction of rutile and corundum at 1300 °C. SEM analysis results indicate that with the increase of temperature, more corundum particles covered by liquid phase, the direct connections between corundum particles are broken and the creep resistance is greatly reduced. The creep curve fitting after 25 hours indicate that the samples enter the steady-state creep stage and the creep property shows linear relations at three different temperatures. The results of steady-state creep stage reflect the high-temperature creep properties of Al_2O_3~78% high-alumina is poor. The poor performance of creep resistance unable to satisfy the industrial demand and is inadequacy for being the low creep refractories.