w(CaO)/w(Al_(2)O_(3))对钙铝基保护渣结晶性能的影响  

Effect of w(CaO)/w(Al_(2)O_(3))on the Crystallization Properties of CaO-Al 2O 3-based Mold Flux

作　　者：亓捷[1,2] 刘承军 张江浩[1,2] 姜茂发 QI Jie;LIU Cheng-jun;ZHANG Jiang-hao;JIANG Mao-fa(Key Laboratory for Ecological Metallurgy of Multimetallic Ores(Ministry of Education),Northeastern University,Shenyang 110819,China;School of Metallurgy,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学多金属共生矿生态化冶金教育部重点实验室,辽宁沈阳110819 [2]东北大学冶金学院,辽宁沈阳110819

出　　处：《东北大学学报（自然科学版）》2021年第12期1717-1723,共7页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(51904064,U1908224,51974075);中国博士后科学基金资助项目(2020T130084,2019M661114);中央高校基本科研业务费专项资金资助项目(N2125013).

摘　　要：利用热丝法测试技术,结合扫描电镜和能谱分析,研究了不同w(CaO)/w(Al_(2)O_(3))条件下钙铝基保护渣的结晶性能.结果表明,较低w(CaO)/w(Al_(2)O_(3))下,保护渣结晶物相为LiAlO 2和CaO·Al_(2)O_(3).其析出由渣中的Li^(+)离子和Ca^(+)离子分别对高聚合度铝氧四面体结构的电荷补偿所致.而且,Li^(+)离子优先参与,LiAlO 2优先析出.较高w(CaO)/w(Al_(2)O_(3))下,结晶物相转变为LiAlO 2和3CaO·Al_(2)O_(3).其变化原因为,CaO相对质量分数提高,保护渣聚合度降低,Ca^(+)离子和低聚合度铝氧四面体结构单元Q 2结合而形成3CaO·Al_(2)O_(3)并析出.随着w(CaO)/w(Al_(2)O_(3))由1.13提高至1.82,钙铝基保护渣析晶能力先减弱然后增强.在w(CaO)/w(Al_(2)O_(3))为1.50和1.82时分别具有最弱和最强的析晶能力.The crystallization properties of CaO-Al_(2)O_(3)-based mold fluxes with different values of w(CaO)/w(Al_(2)O_(3))were studied by using single hot thermocouple technique(SHTT)and scanning electron microscope and energy dispersive spectrometer(SEM-EDS).The results showed that the crystalline phases were LiAlO 2 and CaO·Al_(2)O_(3)with a lower w(CaO)/w(Al_(2)O_(3)).They were formed due to the charge compensation of Li^(+)ions and Ca^(+)ions to aluminum tetrahedral structure with high polymerization degree.Li^(+)ions were preferentially involved,and LiAlO 2 preferentially precipitated.With higher w(CaO)/w(Al_(2)O_(3)),the crystalline phase was transformed into LiAlO 2 and 3CaO·Al_(2)O_(3).The reason for the change was that the relative mass fraction of CaO was increased,accordingly,the degree of polymerization of the mold flux was decreased and 3CaO·Al_(2)O_(3)was formed and precipitated due to the combination of Ca^(+)ions and low-polymerization tetrahedral structural unit Q 2.As the w(CaO)/w(Al_(2)O_(3))was increased from 1.13 to 1.82,the crystallization ability was first weakened and then increased.The crystallization ability was the weakest and the strongest when the w(CaO)/w(Al_(2)O_(3))was 1.50 and 1.82,respectively.

关 键 词：钙铝基保护渣 结晶温度 结晶物相 熔体结构 热丝法 

分 类 号：TF4[冶金工程—钢铁冶金]