稀土元素（REE）是由17個(gè)組成鑭系元素系列的特殊金屬元素：鑭（La）、鈰（Ce）、鐠（Pr）、釹（Nd）、鐠（Pm）、釤（Sm）、銪（Eu）、釓（Gd）、鋱（Tb），鏑（Dy）、鈥（Ho）、鉺（Er）、銩（Tm）、鐿（Yb）、镥（Lu），以及鈧和釔顯示相似鑭系元素的物理化學(xué)性質(zhì)。稀土元素具有獨(dú)特的催化、冶金、核，電、磁和發(fā)光特性。它們的使用表明了它們的戰(zhàn)略重要性在一些新興和多樣化的技術(shù)中這在今天變得越來(lái)越重要社會(huì)。應(yīng)用范圍從常規(guī)（例如，打火機(jī)燧石、玻璃拋光介質(zhì)、汽車發(fā)電機(jī)）高科技（激光、磁鐵、電池、光纖通信電纜），對(duì)于那些具有未來(lái)感的用途（高溫超導(dǎo)性，安全儲(chǔ)存和運(yùn)輸氫以促進(jìn)后碳?xì)浠衔锝?jīng)濟(jì)、環(huán)境和全球變暖以及能源效率問題）。在過去的二十年里，全球稀土需求顯著增加同情地把他們戲劇性地?cái)U(kuò)展到高科技、環(huán)保、經(jīng)濟(jì)環(huán)境。

The rare-earth elements (REE) are a group of seventeen  speciality metals that comprise the lanthanide series of  elements: lanthanum (La), cerium (Ce), praseodymium  (Pr), neodymium (Nd), promethium (Pm), samarium  (Sm), europium (Eu), gadolinium (Gd), terbium (Tb),  dysprosium (Dy), holmium (Ho), erbium (Er), thulium  (Tm), ytterbium (Yb), lutetium (Lu), in addition to  scandium (Sc) and yttrium (Y), which show similar  physical and chemical properties to the lanthanides.  The REE have unique catalytic, metallurgical, nuclear,  electrical, magnetic, and luminescent properties.  Their strategic importance is indicated by their use  in a number of emerging and diverse technologies  that are becoming increasingly significant in today’s  society. Applications range from routine (e.g., lighter  flints, glass polishing mediums, car alternators), to  high-technology (lasers, magnets, batteries, fibre-optic  telecommunication cables), to those that have futuristic  purposes (high-temperature superconductivity,  safe storage and transport of hydrogen for a posthydrocarbon economy, environmental global warming  and energy efficiency issues). Over the last two decades,  the global demands of REE have significantly increased  sympathetically with their dramatic expansion into  high-technological, environmental, and economical  environments.