前言随着科学技术的发展,稀土元素在国民经济中的地位已越来越重要,人们对它的认识也愈为深刻,应用领域正日益扩大。稀土金属具有许多优异的特性,从中可以制备许多具有特殊性能的化合物及合金材料。近年来稀土工业在党和政府的大力扶植下有了较大的发展,形成了一个完整的独立工业 Preface With the development of science and technology, the status of rare earth elements in the national economy has become more and more important. People are also getting more and more profound understanding of it, and the fields of application are expanding day by day. Rare earth metals have many excellent properties from which many compounds and alloys with special properties can be prepared. In recent years, rare earth industry in the Party and government support has undergone significant development, forming a complete independent industry