碱度对烧结矿液相形成性能和微观结构特性的影响  

Effect of basicity on liquid phase formation properties and microstructure of sinter

作　　者：张国成[1] 罗果萍[1] 柴轶凡[1] 王艺慈[1] 宋巍[1] ZHANG Guocheng;LUO Guoping;CHAI Yifan;WANG Yici;SONG Wei(School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,Nei Mongol,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010

出　　处：《钢铁研究学报》2021年第7期584-592,共9页Journal of Iron and Steel Research

基　　金：国家自然科学基金资助项目(51664045)。

摘　　要：采用Factsage 7.1热力学软件模拟计算了碱度对烧结矿液相形成性能和微观结构特性的影响,并开展了不同碱度的烧结杯试验研究。研究表明:随着碱度增加,烧结矿理论液相生成量增加,液相黏度降低,液相中Fe_(2)O_(3)/CaO增加,铁酸钙形成条件改善。当碱度为1.95时,铁酸钙含量最高,CaO与Fe_(2)O_(3)结合形成稳定的铁酸钙粘结相,有利于减少Fe_(2)O_(3)发生还原粉化现象;而继续提高碱度至2.05时,颗粒较粗的褐铁矿和赤铁矿与CaO进一步接触、矿化,使烧结矿赤铁矿含量升高,铁酸钙和磁铁矿含量减少,液相黏度降低,孔隙率增大,烧结矿结构均匀性变差,导致烧结矿基体组织结构抵抗还原过程中产生的晶格畸变能力变差,粉化严重。综合考虑碱度对烧结矿转鼓强度和低温还原粉化性能的影响,在试验所用烧结原料条件下,烧结矿适宜碱度应控制为1.95。Effect of basicity on the liquid phase formation properties was simulated and calculated by using the thermodynamic software Factsage 7.1, and the sintering pot tests with different basicity were carried out. The results show that with the increase of basicity, the theoretical liquid phase production of sinter increases, the liquid phase viscosity decreases, the mass ratio of(Fe_(2)O_(3)/CaO) in the liquid phase composition increases, which is beneficial to improve the formation conditions of calcium ferrite. When the basicity is 1.95, the calcium ferrite binder phase content is the highest, the combination of CaO and Fe_(2)O_(3) to form a stable calcium ferrite binder phase, which is beneficial to reduce the reduction degradation of Fe_(2)O_(3). When the basicity increases to 2.05, the coarser limonite and hematite will further contact and mineralize with CaO, which results in the increase of hematite content, the decrease of calcium ferrite and magnetite content, the decrease of liquid viscosity and the increase of porosity. Thus the uniformity of sinter structure becomes worse, which leads to the deterioration of ability of the sinter matrix structure to resist the lattice distortion generated in the reduction process, as a result, the sinter degradation becomes serious. Comprehensively considering the influence of basicity on the drum strength and low-temperature reduction degradation performance of sinter, the appropriate basicity should be controlled to 1.95 under the sintering raw material condition used in the experiment.

关 键 词：烧结矿碱度 液相形成性能 转鼓强度 低温还原粉化指数 

分 类 号：TF046[冶金工程—冶金物理化学]