沥青铀矿的表面特性研究

目前对铀矿物表面化学性质的研究相对较少,制约了铀矿浮选工艺的研究进展。本文选取铀矿床中分布广泛的沥青铀矿为研究对象,借助显微镜观察、X射线粉晶衍射、红外光谱测试、Zeta电位测试和X射线光电子能谱测试手段,对沥青铀矿的表面特性开展了系统的研究。研究发现,晶体中(110)方向为沥青铀矿的优先破裂面,该面上的U、O比例约为1∶2。由于矿物表面2种不饱和键与H~+和OH~-结合生成化合物的电离、键能的差异,沥青铀矿在纯水中pH为2~11的Zeta电位均为负值。沥青铀矿共存在4个特征红外吸收谱带。矿物表面U主要呈UO_2形式存在,Th多呈ThO_2形式存在,Pb则主要以Pb和PbO形式存在。

Study on Surface Characteristics of Pitchblende

At present,research on the surface chemical properties of uranium minerals is very scanty,which restricts the research progress of uranium ore flotation process.On this account,the pitchblende is selected as the object of study in this paper,because it is widely distributed in uranium deposits.By means of microscopic observation,infrared spectroscopy,XRD test,Zeta potential test and XPS test,a systematic study on surface characteristics of pitchblende is carried out.The research results shows that,the(110) direction of the crystal is the preferential fracture surface of pitchblende,and the ratio of U and O on the surface is about 1 ∶ 2.The two kinds of unsaturated bonds on mineral surface combine with H+ and OH-and produce compounds.The compounds are differing in ionization degree and bond energy.Therefore,the Zeta potential of pitchblende in pure water is negative when the pH value is between 2 and 11.The pitchblende exists in four characteristic absorption bands.On the surface of pitchblende,U is mainly in the form of UO2,Th is mainly in the form of ThO2,and Pb is mainly in the form of Pb and PbO.