烧结矿适宜的SiO2质量分数和碱度

 研究了烧结矿适宜的SiO2质量分数和碱度，用来指导生产具有良好经济技术指标的烧结矿。首先对青钢烧结用铁矿粉进行了基础性能分析，并结合青钢烧结矿生产实际采用烧结杯进行试验，设计了4种SiO2质量分数和3种碱度，研究SiO2质量分数和碱度对烧结生产经济技术指标的影响。研究结果表明，烧结矿二元碱度为1.9，SiO2质量分数为5.4%时，烧结杯试验能取得良好的经济技术指标。借助扫描电镜（SEM）对烧结矿微观结构进行观察，发现随着SiO2质量分数的增加，烧结矿内液相量和溶蚀结构逐渐增多，烧结矿化学成分均匀化，但SiO2质量分数达到5.7%时，烧结矿内硅酸盐类物质过分发展，反而使得烧结矿质量劣化。碱度的提高有利于铁酸钙的发展和黏结相比例的增加，从而提高烧结矿还原性，改善烧结矿质量，但碱度为2.0时也存在玻璃质增多的现象。

Influence of basicity and w(SiO2) on sinter mineral quality

The suitable w(SiO2) and basicity of sinter to guide the production of sinter with good technical and economic indexes was studied. Firstly,the analysis of basic sintering properties iron ore powder used in Qingdao Special Steel Co.,Ltd. was analyzed. Furthermore,on the basis of practical production,sinter pot tests were conducted by varying the binary basicity and the content of SiO2 in sinter to study the effects of the two factors on the technical and economic indexes of sintering. The results showed that the optimal parameters were the binary basicity of 1.9 and w(SiO2) of 5.4%. In the microstructure of sinter,it was found by scanning electron microscope that the higher content of SiO2,the larger liquid phase and dissolution textures and the more homogeneous chemical composition. However,when w(SiO2) was higher than 5.7%,the quality of sintering became degraded because of the over-developed of silicates. The increase of binary basicity is conducive to the development of calcium ferrite and the increase of liquid phase amount,thus increas-ing the reducibility of sinter,improving the quality of sinter. But the increase in glass phase would happen when the bi-nary basicity reached 2.0.