MgO对烧结矿液相形成性能和微观结构特性的影响  

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

作　　者：张国成[1,2] 罗果萍 宋巍[1] 柴轶凡[1] ZHANG Guo-cheng;LUO Guo-ping;SONG Wei;CHAI Yi-fan(School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,Nei Mongol,China;Department of Chemistry,Baotou Teachers'College,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 [2]包头师范学院化学学院,内蒙古包头014010

出　　处：《中国冶金》2021年第10期8-16,共9页China Metallurgy

基　　金：国家自然科学基金资助项目(51664045)。

摘　　要：为了探究MgO对烧结矿液相形成性能和微观结构特性的影响,采用Factsage 7.1热力学软件模拟分析了MgO对烧结矿液相形成性能的影响,并且开展了不同MgO含量的烧结杯试验研究。研究表明,随着MgO含量增加,烧结矿理论液相生成量减少,液相黏度降低,液相中w(Fe_(2)O_(3))/w(CaO)增加,使得混合料中CaO的活度提高,铁酸钙相形成的热力学条件改善;当MgO质量分数由1.60%提高至1.90%,一方面,烧结矿矿相组成中枝晶状铁酸钙相含量增加,针状及板柱状铁酸钙相发展受到抑制,铁酸钙黏结相总量降低,硅酸盐相含量增加,导致液相黏结包裹矿粉颗粒能力变差,固结强度性能受到不利影响;另一方面,由于MgO是高熔点物质,矿化反应过程中,MgO易固溶进入磁铁矿晶格,并在高温固相反应中形成难熔物相,使得烧结矿磁铁矿相含量增加,赤铁矿相含量减少,从而降低烧结矿低温还原反应过程中产生的晶格结构畸变应力,改善低温还原粉化性能。In order to investigate the effect of MgO on liquid phase formation properties and microstructure characteristics of sinter,the thermodynamic software Factsage 7.1 was used to simulate and calculate the effect,and sintering pot tests with different MgO contents were carried out.The result showed that with the increase of MgO content,the theoretical liquid phase production of sinter decreased,the liquid phase viscosity decreased,the mass ratio of w(Fe_(2)O_(3))/w(CaO)in the liquid phase composition increased,which increased the activity of CaO and was beneficial to improve the formation conditions of calcium ferrite.When the mass fraction of MgO increased from 1.60%to 1.90%,on the one hand,the content of dendritic calcium ferrite phase in the sinter mineral phase composition increased,the development of acicular and plate columnar calcium ferrite phase was restrained,the total content of calcium ferrite binding phase decreased,and the content of silicate phase increased,as a result,the ability of liquid phase to bond and enwrap iron ore particles became worse,and the consolidation strength performance was adversely affected.On the other hand,MgO,as a high melting point material,was easy to dissolve into the magnetite lattice during the process of mineralization reaction,forming refractory phase in the high temperature solid state reaction,which increased the content of magnetite and decreased the content of hematite,so as to reduce the lattice distortion stress produced in the process of low temperature reduction reaction of sinter and improve the low-temperature reduction pulverization performance.

关 键 词：MGO 液相生成性能 转鼓强度 低温还原粉化性能 微观结构 

分 类 号：TF046.4[冶金工程—冶金物理化学]