| 渗流作用下风化壳淋积型稀土矿细观孔隙结构演化特征 |
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| 作者姓名： | 陈勋 尹升华 严荣富 王雷鸣 |
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| 作者单位： | 1.北京科技大学金属矿山高效开采与安全教育部重点实验室, 北京 100083 |
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| 基金项目： | 国家自然科学基金重点资助项目（51734001，52034001）；中央高校基本科研业务费专项资金资助项目（FRF-TP-18-003C1）；国家科技部重点领域创新团队资助项目（2018RA4003） |
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| 摘 要： | 为研究风化壳淋积型稀土矿浸出过程中溶液渗流作用对孔隙结构的影响，以去离子水为溶浸液开展浸矿实验。对浸出前后矿样进行显微CT扫描，获取了试样内部结构图像，利用阈值分割算法得到了浸出前后稀土矿样的孔隙结构图像。进而，研究了溶液渗流作用下试样孔隙结构的变化特征，分析了渗流作用对试样孔隙率、孔隙体积、孔隙长度、孔隙宽度和孔隙方位角等参数的影响。结果表明:稀土矿孔隙形状和尺寸在渗流作用下发生显著变化，且在粗细颗粒接触区最为明显；溶液渗流作用使得稀土矿孔隙率增大，孔隙总数量减少，孔隙总体积增大。渗流作用下矿样中小孔隙数量减少，大孔隙数量增多，各尺寸区间的孔隙数量变化率随孔隙尺寸的增大呈现先增大后减小的趋势。溶液渗流作用下孔隙长宽比分布更加集中，孔隙方位角在各角度区间的分布更加均匀，孔隙各向异性增强。
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| 关 键 词： | 风化壳淋积型稀土矿 浸出体系 显微CT扫描 溶液渗流 孔隙结构演化 |
| 收稿时间： | 2021-02-24 |
Evolution characteristics of mesoscopic pore structure of weathered crust elution-deposited rare earth ore under solution seepage |
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| Authors: | CHEN Xun YIN Sheng-hua YAN Rong-fu WANG Lei-ming |
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| Affiliation: | 1.Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Beijing 100083, China2.School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China |
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| Abstract: | In-situ leaching is extensively used in the mining industry to recover rare earths from weathered crust elution-deposited rare earth ore. In the leaching system, the pore structure of rare earth ore is one of the most important factors that influence the leaching performance. A small column leaching experiment was performed with deionized water as a leaching solution to study the effect of solution seepage on pore structure evolution characteristics in the leaching process of weathering crust eluviation rare earth ore. Micro-computed tomography (micro-CT) was performed on the ore sample before and after leaching, and internal structure images of the sample were obtained. The pore structures of the rare earth ore sample were obtained using the threshold segmentation algorithm. The variation characteristics of pore structure of a rare earth ore sample under the action of solution seepage were then studied, and the effects of solution seepage on sample porosity, pore volume, length, width, azimuthal angle, and other parameters were analyzed. The results show that the pore shape and size of rare earth ore change significantly due to solution seepage, most notably in the contact area of the coarse and fine particles. The solution seepage increases the porosity of rare earth ore, decreases the total number of pores, and increases the total volume of pores. Besides, the number of small and medium-sized pores decreases, while the number of large pores increases due to seepage. The change rate of the number of pores in each size interval increases and then decreases as pore size increases. Compared with the initial state, the distribution of pore aspect ratio is more concentrated after the solution seepage. Moreover, the distribution of pore azimuthal angle is more uniform, and the anisotropy of pore structure is enhanced by solution seepage. |
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