注压条件下离子型稀土浸矿过程及孔隙结构演化规律试验研究

为探究注压条件对离子型稀土矿体浸出过程的影响，优化调控方法。以广东仁居离子型稀土矿为研究对象，选取不同孔隙比的稀土重塑土进行室内柱浸试验，监测注压梯度下不同孔隙比的离子型稀土矿浸出浓度、浸出流量、浸出率随时间的变化情况，同时采用核磁共振技术测定浸矿过程孔隙结构等参数。结果表明：离子型稀土矿浸出过程中不同孔径孔隙占比变化是影响浸出效率的重要因素之一。注压条件下，随注压强度增加，浸出率峰出现时间大幅缩短，浸矿过程中试样内部孔隙先由大孔隙和超大孔隙向小中孔隙转化，后期中孔隙向大孔隙转化，而超大孔隙及微孔隙占比进一步降低。注压强度小于10MPa时，随注压强度增加，中孔隙占比呈上升趋势，变化趋势逐渐扩大；注压强度大于10MPa时，随注压强度增加，中孔隙占比呈下降趋势，变化趋势逐渐变缓。

Experimental study on the influence of leaching process and pore structure of ionic rare earth ore under pressure injection conditions

In order to study the in-situ leaching process and Influencing factors of ionic rare earth ore, the Guangdong Renju ionic rare earth ore was taken as the research object to explore the seepage characteristics through the rare earth indoor column leaching test with different pore ratios. Nuclear magnetic resonance (NMR) was used to analyze the pore distribution and proportion after injection pressure leaching. The results show that the pore ratio has a significant effect on the peak time of leaching ion concentration under atmospheric pressure, but has a weak effect on the peak time. Under the injection pressure condition, the injection pressure strength has a great effect on the peak time and leaching rate of leached ion concentration. The higher the injection pressure strength, the greater the seepage flow of leached ion rare earth ore, the lower the peak concentration of rare earth leaching, and the lower leaching rate. Injection pressure leaching results in the reduction of the proportion of micro-pores, and the decomposition of super-large pores into small pores, which significantly increases the proportion of small pores, and the change becomes more obvious with the increase of injection pressure strength. The research results provide a theoretical basis for the improvement of the leaching efficiency of ionic rare earth ores.