【摘要】 离子吸附型稀土矿是关乎我国稀土关键矿产国际竞争优势和资源战略安全的重要矿床类型.为探究离子吸附型矿物的频谱激电响应和流动电位响应特征，本文设计并搭建了一套可同步测量黏质砂土地球物理与水文化学特性的流动系统.该系统基于离子吸附型稀土矿成矿理论和双电层电化学原理，集成电法探测和水文化学测量功能，可测试由不同盐浓度溶液饱和的黏土砂样在不同水力梯度条件下的流动电势差、复电导率和孔隙水压力，并收集孔隙液体进行化学分析.本文基于该系统开展了系列测量工作，包括自来水和不同盐浓度溶液的复电导率以及由不同盐浓度溶液饱和的不同黏质砂土样本的复电导率并计算砂样的地层因子.此外在不同水力梯度条件下同时测量孔隙水压力值和流动电势差，计算砂样的水力及电性参数.实验结果表明，自来水复电导率测量结果与前人研究结论相似、不同盐浓度溶液的复电导率幅值测量结果与电导率仪的测量结果具有较强线性相关、饱和石英砂复电导率测量结果估计的砂样地层因子在理论范围内、不同盐浓度溶液和不同黏土含量的土样复电导率测量结果与前人研究结论相似；饱和情况下，不同盐浓度溶液测量的平均电势差和平均流量随平均压力差呈线性变化，由测量结果评估的土样饱和水力传导率及流动电位耦合系数在理论范围内.相关实验结论验证了该装置系统的有效性和稳定性，证明该流动系统测量离子吸附型稀土矿水文化学特性与地球物理响应的可行性，为进一步基于离子吸附型稀土矿的成矿富集机理探究其成矿化学特性和流动电位信号与激电响应之间的联系以及潜在勘探技术奠定了实验基础.更多还原

【Abstract】 Ion-absorption type rare earth deposits play a crucial role in China’s global competitiveness and resource security concerning critical rare earth minerals. To explore the spectral induced polarization(SIP) and streaming potential(SP) response characteristics of ion-absorption minerals, we designed and developed a flow system capable of simultaneously measuring the geophysical and hydrochemical properties of clayey sand. This system is based on the metallogenic theory of ion-absorption type rare earth deposits and the principles of the electrical double layer, integrating both electrical and hydrochemical measurement functions. The system is capable of measuring streaming potential difference, complex conductivity, and pore water pressure of clayey sand samples saturated with different salinity solutions under varying hydraulic gradients. Additionally, it facilitates the collection of pore fluids for subsequent chemical analysis. A series of measurements were conducted, including the complex conductivity of tap water and solutions with different salinities, as well as the complex conductivity of different clayey sand samples saturated with solutions of varying salinity. The formation factor of the sand samples was also estimated. Moreover, pore water pressure and streaming potential difference were measured simultaneously under different hydraulic gradients to evaluate the hydraulic and electrical parameters of the sand samples. The experimental results indicate that the complex conductivity of tap water is consistent with previous studies. The measured complex conductivity for solutions with varying salinities exhibits a strong linear correlation with values obtained from a conductivity meter. Furthermore, the formation factor of the sand samples, estimated from the complex conductivity of saturated quartz sand, falls within the theoretical range, and the complex conductivity of clayey sand samples with different salinities and clay contents aligns closely with conclusions from earlier studies. Additionally, under saturated conditions, both the average streaming potential difference and average flow rate show a linear relationship with the average pressure difference. The saturated hydraulic conductivity and the streaming potential coupling coefficient, as derived from the measurements, also fall within the theoretical range. Overall, these findings validate the efficacy and stability of the proposed experimental system, laying a solid foundation for investigating the relationship between the chemical characteristics of ore formation and electrical responses(SIP and SP) in line with the metallogenic enrichment mechanism, and for developing potential exploration techniques for ionabsorption type rare earth deposits.更多还原