Rare earth elements are lanthanide elements in the periodic table of chemical elements, lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium oxide (Yb), lutetium (Lu), yttrium (Y) and scandium (Sc), a total of 17 elements called for rare earth elements.Rare earth elements have been widely used in electronics, petrochemical, metallurgy, machinery, energy, light industry, environmental protection, agriculture and other fields.Rare earths can be used to produce fluorescent materials, rare earth metal hydride battery materials, electric light source materials, permanent magnet materials, hydrogen storage materials, catalytic materials, precision ceramic materials, laser materials, superconducting materials, magnetostrictive materials, magneto-optical storage materials, fiber optic materials, etc.