湖北宜昌磷矿伴生稀土元素分布规律、赋存状态及其开发利用前景分析

Distribution,occurrence and exploration prospect of associated rare earth elements in Yichang phosphate deposit,Hubei Province

【研究目的】湖北省宜昌磷矿中伴生有稀土元素,研究其分布规律及赋存状态,对稀土元素的回收利用具有重要意义,其作为伴生矿产的综合利用将成为未来稀土矿的重要来源。【研究方法】本文以含稀土磷块岩为主要研究对象,在系统取样的基础上,开展岩矿鉴定、全岩地球化学分析、XRD衍射分析、SEM观察、LA-ICP-MS测试等工作。【研究结果】磷块岩中稀土元素总量ΣREE+Y为63.5×10^(-6)~271.8×10^(-6),不同层位或不同岩性的磷块岩中稀土元素含量有所差异。【结论】稀土元素含量受岩性控制明显,由白云岩→白云质磷块岩→致密块状磷矿石→泥质条带磷块岩→泥岩,含量逐渐升高。微量元素反映出宜昌磷矿的古气候以干热为主,西北部略表现出温暖湿润特点;Ce异常、V/Ni和Y/Ho比值反映海水中EH条件从底部到顶部,即从Ph22成磷期到Ph13成磷期,形成水体环境逐渐氧化。宜昌磷矿中稀土元素总量整体较低,且泥岩较磷块岩中含量高,表明吸附态稀土较类质同象稀土含量高。宜昌伴生稀土磷矿资源丰富,利用合理的技术对稀土元素进行综合回收,对宜昌磷矿资源的合理利用和经济发展有重要意义。

[Objective]The Yichang phosphate ore in Hubei Province contains associated rare earth elements.Studying their distribution patterns and occurrence states is of significant importance for the recycling and utilization of rare earth elements.Additionally,the comprehensive utilization of associated minerals is expected to become a crucial source for future rare earth ores.[Methods]This study primarily focuses on rare earth-containing phosphate rocks.Based on systematic sampling,analyses including rock and mineral identification,whole-rock geochemical analysis,XRD diffraction analysis,SEM observation,and LA-ICP-MS testing are carried out.[Results]The total rare earth element content(ΣREE+Y)in phosphate rock ranges from 63.5×10^(-6) to 271.8×10^(-6).There are variations in rare earth element contents among different layers or rock types of phosphate rock.[Conclusions]The content of rare earth elements is notably controlled by rock types,with an increase from dolomite→dolomitic phosphorite→dense massive phosphorite→argillaceous banded phosphorite to mudstone.Trace elements compositions reflect the ancient climate of the Yichang phosphate deposits,characterized mainly by a dry and hot climate,with a slightly warm and humid characteristic in the northwest.Ce anomaly,V/Ni and Y/Ho ratio reflect the oxidation of seawater conditions from the bottom to the top,corresponding to the the Ph22 to the Ph13 phosphogenesis periods.The total rare earth elements content in the Yichang phosphate deposit are relatively low,and mudstone has higher content compared to phosphate rocks,indicating a higher concentration of adsorbed rare earth elements than the isomorphic rare earth elements.The rare earth resources associated with the Yichang phosphate deposit can be comprehensively recovered using appropriate technologies,holding significant importance for the rational utilization of the Yichang phosphate ore resources and economic development.