稀土元素常以R或RE符号表示,属周期表中第ⅢB族。近年来,由于稀土应用研究的进展,分离技术的开发,稀土已广泛地应用于冶金、石油化工、玻璃陶瓷、永磁材料、医学或农业等领域,同时,由于稀土独特的性能,已在节能领域中发挥了极大的作用。例如用稀土化合物制成的灯光照明材料,经应用证明,节电一般在15-20％。这是由于稀土离子具有稳定的S~2P~0饱和电子层,但是一旦进入外层以内的 Rare earth elements often with R or RE symbols that are in the periodic table Group Ⅲ B. In recent years, rare earths have been widely used in the fields of metallurgy, petrochemical, glass ceramics, permanent magnet materials, medicine or agriculture due to the research and application of rare earths and the development of separation technologies. At the same time, due to the unique properties of rare earths, Has played a significant role in the field. For example, with rare earth compounds made of lighting materials, the application shows that power-saving is generally 15-20%. This is because the rare earth ions have a stable S ~ 2P ~ 0 saturated electron layer, but once inside the outer layer