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独居石是稀土、钍和铀的共生矿物,含有钍系、铀镭系和锕铀系等三个放射系的几十种核素,其中寿命较长的放射性核素有:~(234)U、~(235)U,~(238)U、~(231)Pa、~(228)Th、~(?)Th、~(232)Th、~(227)Ac、~(226)Ra、~(228)Ra、~(210)Pb、~(21(?))Po等。从独居石中提取稀土元素,不可避免地夹带一些放射性元素。稀土产品中带有放射性杂质,使用时易引起环境污染,这是人们十分关心的问题。锕和稀土同是ⅢB族元素,化学性质相似,很难分离。因此,通常认为氯化稀土中放射性杂质是:~(22(?))Ac
Monazite is a rare earth, thorium and uranium symbiotic minerals, including thorium, uranium radium and actinides uranium system of dozens of radionuclides radionuclides, of which long-lived radionuclides are: (234) U Th, Th, ~ (232) Th, ~ (227) Ac, ~ (226) Ra, ~ (235) U, ~ (228) Ra, ~ (210) Pb, ~ (21 (?)) Po and so on. Extracting rare earth elements from monazite inevitably entrains some radioactive elements. Rare earth products with radioactive impurities, when used easily lead to environmental pollution, which is a matter of great concern to people. Actinium and rare earth with the same group IIB elements, similar chemical properties, it is difficult to separate. Therefore, it is generally considered that rare earth chloride radioactive impurities: ~ (22 (?)) Ac