铝热还原制备Al-Sc合金的热力学调控

Thermodynamic Control of Preparation of Al-Sc Alloy by Aluminothermic Reduction

通过热力学分析,建立了1223 K下传统Al热还原Sc2O3制备Al-Sc合金反应平衡的热力学模型。结果表明,对于传统Al热还原法, Sc收率随合金的Sc浓度升高而降低。通过传统Al热还原方法制备了不同Sc浓度的合金,验证了模型的可用性。为提高Sc回收率,在传统Al热还原法之基础上提出分段逆流Al热还原制备Al-Sc合金的方法,并建立了1223 K温度下分三段情况下各段反应的热力学模型。结果表明,通过对各段反应的热力学调控,能保证最终制备出高含Sc量合金的同时提高Sc2O3原料利用率。通过分段逆流热还原法制备了Sc浓度2%(质量分数)左右的Al-Sc合金,综合Sc收率达到90%以上。

The thermodynamic model for the reaction equilibrium of Al-Sc alloy prepared by traditional aluminothermic reduction of Sc2O3 at 1223 K was established by thermodynamic analysis. The results showed that for the traditional aluminothermic reduction method, the Sc recovery rate decreased with increasing Sc content of the alloy. Alloys with different Sc content were prepared by traditional aluminothermic reduction methods and the usability of the model was verified. In order to improve the Sc recovery rate, based on the traditional Al thermal reduction method, a method of preparing Al-Sc alloy by segmental countercurrent aluminothermic reduction was proposed, and a thermodynamic model of each reaction in three phases at 1223 K was established. The results showed that the thermodynamic regulation of the reactions in each stage can ensure the final preparation of high-Sc alloys and improve the utilization of Sc2O3 raw materials. The Al-Sc alloy with a Sc content of about 2% was prepared by a segmented countercurrent aluminothermic reduction method, and the comprehensive Sc recovery rate was above 90%.