基于挥发影响的CaF2-Al2O3二元相图测定与解析

 为实现对CaF₂-Al₂O₃二元相图做出有效测定与评价,首先利用FactSage软件计算和熔点测试绘制了CaF₂-Al₂O₃二元相图,共晶点成分为10%Al₂O₃-90%CaF₂(质量分数),共晶温度为1 340 ℃。通过热重-差热试验发现,该二元体系升温过程存在明显失重和吸热,温度达到1 500 ℃时,90%CaF₂-10%Al₂O₃的试样失重率可达27%,失重主要是CaF₂挥发,并伴随明显吸热峰。基于失重及挥发反应,对熔点测定过程进行成分修正,得到新的CaF₂-Al₂O₃二元相图,共晶点成分为12%Al₂O₃-88%CaF₂(质量分数),共晶温度为1 340 ℃。最后,通过荧光分析对熔化后的渣样进行成分检测,结果与新的相图基本吻合。研究结果对含易挥发组元炉渣熔点测定及相图的绘制和解析具有参考价值。

Determination and analysis of CaF2-Al2O3 binary phase diagram based on volatilization effect

In order to effectively measure and evaluate the binary phase diagram of CaF₂-Al₂O₃,the binary phase diagram of CaF₂-Al₂O₃ was drawn by FactSage software calculation and melting point tests. The eutectic point composition was 10% Al₂O₃-90% CaF₂, and the eutectic temperature was 1 340 ℃. TG-DSC tests showed that the binary system had an obvious weight loss and endotherm during the heating process. The weight loss rate of 90% CaF₂-10% Al₂O₃ can reach 27% at 1 500 ℃ and the main volatile was CaF₂. A new phase diagram of CaF₂-Al₂O₃ was obtained based on the weightlessness and volatilization reaction. The composition of the eutectic point was 12% Al₂O₃-88% CaF₂, and the eutectic temperature was 1 340 ℃. Finally, the XRF detection results of the slag after melting are basically consistent with the new phase diagram. The results are of reference value to the determination of the melting point of slag containing volatile components and the drawing and analysis of phase diagram.