| In this paper; the influences of sesquioxide(Al2O3, Cr2O3, Fe2O3) on properties of the magnesia chrome refractories were studied, and the behaviors of chemical ingredients (Al2O3, Cr2O3 Fe2O3) in the magnesia chrome bricks were discussed and analyzed . The results show that: (1) as the Al2O3 content increases, the bulk density, the thermal shock resistance, and the high-temperature strength of the magnesia chrome bricks will increase, and the apparent porosity will decrease; (2) with the increase of Cr2O3 content, the apparent porosity and the thermal shock resistance of the magnesia chrome bricks will increase, while the high-temperature strength and the bulk density will decrease; (3) with the increase of Fe2O3 content, the apparent porosity of the Magnesia chrome bricks will increase, while the bulk density, the thermal shock resistance and the high-temperature strength will decrease. Therefore, to increase the A12O3 content and to decrease the Fe2O3 content of the magnesia chrome bricks will improve the performance of the magnesia chrome bricks, the Gr2O3 content should be limited.The influences of additive (ZrO2) on the magnesia chrome refractory properties are also investigated, and characteristic of additive (ZrO2) in the magnesia chrome bricks are analyzed further The results show that the mechanical properties of the magnesia chrome bricks will be improved by adding the additive. However, the content of ZrO2 in the magnesia chrome bricks should be limited.The resistances o f refractories-magnesia b rick, magnesia alurnina b rick, m agnesia a laminachrome brick, magnesia chrome brick, alumina chrome brick and foreign brick produced in the Austria to slag were also studied and compared by the method of stationary crucible. By means of OM and X-ray, the microstructural changes of the specimens before and after stationary crucible testing were examined and the corrosion mechanism of the slag to the refractories was discussed The results show that: (1) The influence of temperature on the slag resistance of refractoris is very significant With the increase of temperature, the slag's erosion to refractories increases; (2) The slag reacts with the periclase in refractories, which results in the dissolving of periclase in fayalite slag, That is the main characteristicof the corrosion mechanism of the slag to magnesia chrome refractories, As far as integral performance of the refractories used in the ISA/Ausmelt furnace is concerned, the performance of domestic magnesia chrome bricks is no less than that of the foreign bricks, which is expected to replace the foreign bricks in order to realize the nationalization of the refractories, and gain a remarkable social and economic profit. |
