Research On Fluidity Of High Titanium Oxide-Containing BF Slag With High Magnisia Content

With the rapid development of iron and steel industries in China recently, the demand of iron ore increases dramatically, which leads to the rising price of iron ore, and the competitive pressure rises, which results in the deceasing price of pig iron. The BF of Pan Xi which is smelts V-Ti magnetite as raw materials is confronted with the same situation. If the local ores were used for ironmaking, the cost of iron can be reduced greatly.Bai Ma ore is cheap, the content of MgO is higher than Pan Jing ore, this will certainly increases the MgO content in slag which may cause a major change in liquidity and stability of BF slag, it is harder to operate BF. Researching about influence on fluidity of high magnisia and high titanium oxide-containing BF slag is significance.This thesis is based on the blast furnace slag of Pan Xi, discussing the influence of the binary basicity (R2), W(MgO) W(TiO2),w(Al2O3) on the slag viscosity and melting temperature of high titanium oxide-containing BF Slag, studying the effect of MgO content and temperature on BF slag mineral composition, establishing the slag viscosity model. The conclusions are as follows:(1) When the TiO2 content is fixed at 20 percent and Al2O3 14 percent, for the low temperature viscosity, at high content of MgO, the higher R2, the greater influence on viscosity, the higher content of MgO, the higher viscosity; the melting temperature increases as the MgO content or the basicity increases, but the MgO content affects more greatly; when the Al2O3 content increases from 12 percent to 16 percent, the melting temperature also increases.(2) When the TiO2 content varies at 22%?24%, R2:2:1.0?1.1, w(MgO):10%?12% and W(Al2O3) fixed atl4%, each composition has a smaller effect on the viscosity and the melting temperature, but compared with the high temperature viscosity of the TiO2 of 20 percent, the viscosity decreases when TiO2 is added; the melting temperature has a positive linear relation with the content of (CaO+MgO+TiO2)/(SiO2+Al2O3).(3) The primary phase which we study is baikovite; at high temperature, the primary phase has few changes, which is mainly made of perovskite and baikovite and contains a few of spinel, quartz and glass phase; when the temperature decreases, the main phase becomes perovskite.(4) By using regression analysis, a viscosity model was established to describe blast furnace slag with high magnesia and titanium. The model has a smaller deviation and is in good agreement with the actually measured value. This model can be a good description for the changing rule of the viscosity of Pan Xi BF slag.(5) For the production, when greater quantities of Bai Ma ore is used, the binary basicity should be controlled in low extent, such as 1.0?1-1; the MgO content in raw material can be enlarged when the Al2O3 content is decreased in the slag; the TiO2 content and the temperature of melting iron should be strictly controlled in actual production; the TiO2 content is not suitable if exceeded 24%.