东北大学学报(自然科学版) ›› 2021, Vol. 42 ›› Issue (12): 1717-1723.DOI: 10.12068/j.issn.1005-3026.2021.12.007

• 材料与冶金 • 上一篇    下一篇

w(CaO)/w(Al2O3)对钙铝基保护渣结晶性能的影响

亓捷1,2, 刘承军1,2, 张江浩1,2, 姜茂发1,2   

  1. (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)
  • 修回日期:2021-05-06 接受日期:2021-05-06 发布日期:2021-12-17
  • 通讯作者: 亓捷
  • 作者简介:亓捷(1987- ),男,山东莱芜人,东北大学讲师; 刘承军(1974- ),男,河南获嘉人,东北大学教授,博士生导师; 姜茂发(1955- ),男,山东栖霞人,东北大学教授,博士生导师.
  • 基金资助:
    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).

Effect of w(CaO)/w(Al2O3) on the Crystallization Properties of CaO-Al2O3-based Mold Flux

QI Jie1,2, LIU Cheng-jun1,2, ZHANG Jiang-hao1,2, JIANG Mao-fa1,2   

  1. 1. Key Laboratory for Ecological Metallurgy of Multimetallic Ores
  • Revised:2021-05-06 Accepted:2021-05-06 Published:2021-12-17
  • Contact: QI Jie
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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(Al2O3)条件下钙铝基保护渣的结晶性能.结果表明,较低w(CaO)/w(Al2O3)下,保护渣结晶物相为LiAlO2和CaO·Al2O3.其析出由渣中的Li+离子和Ca2+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,LiAlO2优先析出.较高w(CaO)/w(Al2O3)下,结晶物相转变为LiAlO2和3CaO·Al2O3.其变化原因为,CaO相对质量分数提高,保护渣聚合度降低,Ca2+离子和低聚合度铝氧四面体结构单元Q2结合而形成3CaO·Al2O3并析出.随着w(CaO)/w(Al2O3)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(Al2O3)为1.50和1.82时分别具有最弱和最强的析晶能力.

关键词: 钙铝基保护渣;结晶温度;结晶物相;熔体结构;热丝法

Abstract: The crystallization properties of CaO-Al2O3-based mold fluxes with different values of w(CaO)/w(Al2O3) 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 LiAlO2 and CaO·Al2O3 with a lower w(CaO)/w(Al2O3). They were formed due to the charge compensation of Li+ions and Ca2+ ions to aluminum tetrahedral structure with high polymerization degree. Li+ions were preferentially involved, and LiAlO2 preferentially precipitated. With higher w(CaO)/w(Al2O3), the crystalline phase was transformed into LiAlO2 and 3CaO·Al2O3. 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·Al2O3 was formed and precipitated due to the combination of Ca2+ ions and low-polymerization tetrahedral structural unit Q2. As the w(CaO)/w(Al2O3) 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(Al2O3) was 1.50 and 1.82, respectively.

Key words: CaO-Al2O3-based mold flux; crystallization temperature; crystalline phase; melt structure; SHTT(single hot thermocouple technique)

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