相山铀矿田特富矿中铀磷关系的模拟实验研究

相山铀矿田中磷灰石对生成特富铀矿有着十分重要的作用。在研究特富矿体中含磷矿物的成分及矿物学特征,配合特富铀矿石硅酸盐化学分析结果的矿物计算及对特富铀矿石与蚀变岩、低品位铀矿石的化学成分比较的基础上,结合对铀成矿热液体系下一系列反应方程的热力学计算进行实验模拟。实验模拟的结果表明,氧化还原介质的变化不是磷灰石形成的重要条件,溶液体系中的pH值降低是特富矿形成的重要条件。磷灰石在弱酸性介质中吸附铀构成"铀磷共沉淀"之后,由于磷灰石的结晶,造成"铀、磷分离",从而使铀变得更富。这一研究成果很好地解释了富矿中磷灰石大量存在,而贫矿中磷灰石很少出现的客观地质事实。

The Geochemical Experimental Study on the Relationship between Uranium and Phosphor in Xiangshan Rich Uranium Mineralization

The apatite plays an important role in Xiangshan rich uranium mineralization. The chemical component and mineral composition of phosphor-bearing minerals in rich uranium ores have been extensively analyzed. The geochemical experiments and thermodynamic calculation have been carried out to simulate the uranium mineralization in order to study the relationship between uranium and phosphor in Xiangshan rich uranium mineralization. The results show that pH not the redox condition is the key factor to the apatite precipitation. During uranium mineralization, firstly amorphous phosphorous substances adsorb uranium and then U, P co-precipitation in weak acid condition. Subsequently apatite crystallization make the separation uranium from apatite, as a result, which leads to formation of extremely-rich uranium ore bodies. This research presents a good explanation of co-existence of apatite and rich uranium ores.