铀尾矿酸浸过程中的矿物学性质变化研究

Study on Mineralogical Characteristics Variation During Acid Leaching of Uranium Tailings

脉石含量高和矿物学性质复杂是导致低品位铀尾矿中的铀难以进一步回收的主要原因,而破坏复杂的脉石矿物结构是提高铀解离的有效途径.本文在详细分析了铀尾矿工艺矿物学性质的基础上,通过研究五种氧化剂(H_2O_2、MnO_2、Fe_2(SO_4)_3、HF、HClO_4)对铀尾矿粒径分布、形貌特征和物相组成的影响,揭示了酸浸过程中氧化剂与脉石矿物之间的作用规律.研究结果表明,H_2O_2可将硅酸铁盐矿物分解而使铀尾矿粒径变小,MnO_2可将硅酸铁盐转化为硅酸锰盐并伴随着硅酸锰盐物相的结晶长大,Fe_2(SO_4)_3对脉石矿物无破坏作用,反而能使脉石颗粒发生絮凝,HClO_4与HF可在脉石矿物表面或内部造成强烈的腐蚀而形成细小的孔洞.

The high content of gangue and complex mineralogy characteristics in low-grade uranium tailings result in recycling uranium difficulty.Thus, destroying the complex mineral structure of gangue is an efficient route to improve uranium dissociation rate.Based on the detailed analysis of technological mineralogy of uranium tailings, the research reveals reac- tion mechanism between oxidants and gangue minerals by studying the effect of five oxi- dants （ H2O2 ,MnO2 ,Fe2（ SO4 ） 3 ,HF ,HCIO4 ） on particle size distribution, morphology fea- tures and phase composition changes of tailings during acid leaching.The results indicate that H202 is able to reduce the particle size by decomposing iron silicate minerals.MnO2 can make iron silicate convert to manganese silicate along with its crystal growing up. Fe2（SO4） 3 has no effect on destroying gangue minerals, on the contrary, it can make gangue particles flocculation.HC104 and HF can cause significant corrosion and form tiny holes on the surface and inside of gangue minerals.