超高TiO2高炉渣黏度及熔化性温度

 提高高炉炉料中钒钛磁铁矿的配比(大于80%,甚至达到100%)对于实现攀西地区钒钛磁铁矿资源的深度开发与综合利用意义重大。针对高配比钒钛矿带来超高TiO₂高炉渣的情况,提出了“以镁代钙”的新造渣理念。系统地研究了w(TiO₂)和w(MgO)/ w(CaO) 对CaO-SiO₂-TiO₂-MgO-Al₂O₃渣系黏度和熔化性温度的影响规律。结果表明,惰性气氛下,随着w(TiO₂)从20%增加到34%,炉渣黏度逐渐减小;随着w(MgO)/ w(CaO) 从0.32增加到0.65,炉渣黏度略有增大。炉渣熔化性温度随着w(TiO₂)增加先升高后降低。“以镁代钙” w(MgO)/ w(CaO) 在0.32～0.65范围内增加时,熔化性温度呈先明显降低后略有升高的趋势, w(MgO)/ w(CaO)在0.57附近时,(w(MgO)为12%)炉渣熔化性温度达到最低点,降低幅度约为50 ℃。“以镁代钙”使得炉渣液相区从钙钛矿析出区域附近逐渐移至钙钛矿相与镁铝尖晶石相之间宽阔的区域。采用“以镁代钙” w(MgO)/ w(CaO) 造渣理念对降低超高TiO₂高炉渣熔化性温度具有可行性。

Viscosity and free running temperature of ultra-high TiO2 bearing blast furnace slag

Increasing the proportion of V-Ti-magnetite ore in the burden of blast furnace (over 80% even 100%) is of a great significance to the deep development and comprehensive utilization of V-Ti-magnetite resources ore in Panxi area. In view of the situation that the high proportion of V-Ti-magnetite ore brings ultra-high TiO₂ blast furnace slag, the technology of "replacing CaO with MgO" for the slag optimization was proposed. The effect of the w(TiO₂) and w(MgO)/ w(CaO) on the viscosity and free running temperature of CaO-SiO₂-TiO₂-MgO-Al₂O₃slag were investigated. The results indicated that the viscosity evidently decreases with increasing w(TiO₂) at a range of 20% to 34%. Conversely, increasing w(MgO)/ w(CaO) from 0.32 to 0.65 causes a slight increase of viscosity of the slag. The free running temperature firstly increases, then slightly decreased with w(TiO₂). However, the free running temperature firstly decreases, then increases with w(MgO)/ w(CaO). When w(MgO)/ w(CaO) is near 0.57 (w(MgO) is 12%), the slag free running temperature reaches the lowest point, and the range is about 50 ℃. "Replacing CaO with MgO" leads to the slag liquid phase area move from the vicinity of perovskite precipitated phase to a wide area between perovskite phase and spinel phase. It is feasible to reduce the free running temperature of slag by using "replacing CaO with MgO" w(MgO)/ w(CaO) slag-making, which has important theoretical significance for high-efficiency blast furnace ironmaking process with V-Ti-magnetite ore.