高纯金属钪制备研究进展

Research progress in preparation of high-purity scandium metal

稀土元素钪是一种重要的稀土元素,广泛应用于合金、陶瓷等结构材料及燃料电池电解质、射频滤波器等功能材料领域。本文以高纯金属钪的制备工艺展开探讨,先后介绍了氟化钪、无水氯化钪的制取方法,然后详细阐述了卤化钪的金属热还原工艺和粗钪高温真空蒸馏提纯中不同杂质的处理方法,接着探讨了金属钪深度除杂相关的区熔、电迁移、真空电子束熔炼技术。最后指出,无水氯化钪镁热还原制备金属钪相比氟化钪钙热还原技术具有温度低、环境友好、成本小等优势。未来,金属钪的制备研究可集中于金属热还原无水氯化钪进行,通过多次高温真空蒸馏和电子束熔炼脱除杂质元素,使高纯金属钪产品纯度达到4 N甚至5 N级别。真空电子束熔炼、接力区熔法等技术在超高纯金属钪及其他稀土金属的制备领域具有广阔的发展前景。

Scandium is an important rare earth element widely used in structural materials such as alloys and ceramics, as well as functional materials such as fuel cell electrolytes and radio frequency filters. In this paper, the preparation methods of scandium fluoride and anhydrous scandium chloride are introduced successively, and then the metal thermal reduction process of scandium halide and the treatment methods of different impurities in crude scandium distillation and purification are described in detail. Then, the further purification and impurity removal methods using zone melting, electromigration and vacuum electron beam melting technologies are discussed. Comparing with calciothermic reduction technology with scandium fluoride, the magnesiothermic reduction technology with scandium chloride to prepare metal scandium has the advantages of low temperature, environmental friendliness and low cost. In the future, the research on the preparation of metal scandium can be focused on the metal thermal reduction of anhydrous scandium chloride. The impurity elements can be removed by multiple high temperature vacuum distillation and electron beam melting, so that the purity of metal scandium can reach 4N or even 5N level. Vacuum electron beam melting, relay zone melting and other technologies have broad development prospects in the preparation of ultra-high purity metal scandium and other rare earth metals.