MgO对铁矿粉烧结液相生成的影响

Effect of MgO on Liquid Phase Generation in the Sintering Process of Iron Ore Powder

在准化学平衡条件下,采用相平衡法研究了不同温度及Al2O3含量条件下,MgO对Fe2O3-SiO2-CaO-Al2O3-MgO五元系内铁酸钙生成过程的影响。利用X射线衍射和偏光显微镜分别对试样进行了矿物定量及矿相结构分析。实验结果表明:R=1.8的烧结试样中,添加MgO对铁酸钙的生成及晶型有一定影响;随着温度升高,铁酸钙生成量明显增加,矿相结构分布趋于均匀,固液相之间胶结逐渐紧密;1300℃时MgO含量变化对促进铁酸钙的生成作用较明显;1350℃时MgO含量变化对矿相微观结构转变起明显作用,特别是对铁酸钙的晶型有较大影响。

Under the condition of quasi-chemical balance,phase equilibrium method is used to study the effect of MgO on the generation of calcium ferrite in the Fe2O3-SiO2-CaO-Al2O3-MgO system under the different conditions,including different temperature and different Al2O3 addition. Quantitative analysis and micro structure analysis were made for the ore samples by using X-ray diffraction and polarizing microscope,respectively. Results show that,for the sinter with the basicity of 1. 8,the addition of MgO has an effect on the formation and crystal shape of calcium ferrite. The generation of calcium ferrite increased obviously with the increased temperature,with mineral micro structure tending to a uniform distribution,a gradual close cementation between solid and liquid phase. The content variation of MgO contributes greatly to the generation of calcium ferrite at 1 300 ℃,and has obvious effect on the mineral micro structure,especially the crystal type of calcium ferrite at 1 350 ℃.