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稀土元素共有17种,属元素周期表IIIB族,包括原子序数51—71的镧系元素15个,即镧、铈、镨、钕、钷、钐、铕、钆、铽、镝、钬、铒、铥、镱、镥以及与镧系化学性质相似的钇和钪。依化学性质可以分为两组:前七种为铈组,也叫轻稀土,后面均称为重稀土。应用于农业的稀土产品则是它们的氧化混合物。目前农用稀土产品原料主要来自内蒙古地区的铌-稀土-铁矿床中的稀土资源。稀土农用产品就是将精稀土矿用溶液萃取法进行钕-钐分组,将钐以后的稀土除去,而留下钐以前的轻稀土组分。农用稀土产品有硝酸稀土和氯化稀土两种,应用于农作物的主要是硝酸稀土。
A total of 17 kinds of rare earth elements, belonging to the Group IIIB of the Periodic Table, including 15 lanthanides with atomic numbers 51-71, namely lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, , 铥, ytterbium, 镥 and yttrium and scandium similar to the lanthanide chemistry. According to the chemical properties can be divided into two groups: the first seven species for the cerium group, also known as light rare earth, followed by known as heavy rare earth. Rare earth products used in agriculture are their oxidized mixtures. At present, the main raw material for agricultural rare earth products from rare earth resources in the niobium - rare earth - iron deposits in Inner Mongolia. Rare earth agricultural products is the neodymium - samarium grouping solution of rare earth ore by solution extraction, the rare earth after Samarium removed, leaving samarium before the light rare earth components. Rare earth nitrate products are rare earth nitrate and rare earth chloride are two, mainly used in agricultural crops is rare earth nitrate.