重新认识还原作用在铀成矿中的贡献

铀是一种变价元素,在自然界主要以六价和四价离子的化合物形式存在。一些学者特别强调U~(6+)被还原为U~(4+)在成矿中的重要性。但实际上,作为成矿作用产物的铀矿物中都含有一定量的U~(6+),或铀以UO_2]~(2+)形式形成铀酰矿物。大量地质现象和室内实验资料也表明,还原作用有助于铀成矿作用的进行,但并不都是直接通过U~(6+)还原为U~(4+)成矿,而多是通过对热液/流体性质的改变或其它方式促进铀的沉淀和富集。

Recognition on the Role of Reducing Action in Uranium Metallization

Uranium is a multi valene element,and mainly occurs in hexavalent and tetravalent ion com-pound in the nature.Some scholars specially stress the importance of uranium reduction from U6+to U4+in the metallization.However,the products of uranium metallization always contain some U6+ or the as UO2 ]2+ in uranyl mineral.Lots of geological observation and experimental data shew that reduction favor the process of metallization but not all the metallization are finished by directly reducing U6+ to U4+,and most metallization was caused by the nature change of uranous hydrothermal liquid/fluid or the environment factors prompting uranium precipitation and enrichment.