尹升华, 陈勋, 刘超, 王雷鸣, 严荣富. 矿石颗粒级配对堆浸体系三维孔隙结构的影响[J]. 工程科学学报, 2020, 42(8): 972-979. DOI: 10.13374/j.issn2095-9389.2020.01.17.002
引用本文: 尹升华, 陈勋, 刘超, 王雷鸣, 严荣富. 矿石颗粒级配对堆浸体系三维孔隙结构的影响[J]. 工程科学学报, 2020, 42(8): 972-979. DOI: 10.13374/j.issn2095-9389.2020.01.17.002
YIN Sheng-hua, CHEN Xun, LIU Chao, WANG Lei-ming, YAN Rong-fu. Effects of ore size distribution on the pore structure characteristics of packed ore beds[J]. Chinese Journal of Engineering, 2020, 42(8): 972-979. DOI: 10.13374/j.issn2095-9389.2020.01.17.002
Citation: YIN Sheng-hua, CHEN Xun, LIU Chao, WANG Lei-ming, YAN Rong-fu. Effects of ore size distribution on the pore structure characteristics of packed ore beds[J]. Chinese Journal of Engineering, 2020, 42(8): 972-979. DOI: 10.13374/j.issn2095-9389.2020.01.17.002

矿石颗粒级配对堆浸体系三维孔隙结构的影响

Effects of ore size distribution on the pore structure characteristics of packed ore beds

  • 摘要: 为研究堆浸体系矿石粒径分布对孔隙结构的影响,对不同级配矿岩散体构成的浸柱开展显微CT扫描测试,得到浸柱内部结构图像。通过阈值分割算法对孔隙结构进行提取,建立浸柱三维孔隙模型,对浸柱体孔隙率和面孔隙率的空间分布特征进行研究。利用最大球算法构建浸柱孔隙网络模型,进而分析矿石粒径分布对孔喉半径、喉道长度、孔喉体积、形状因子和配位数等参数的影响规律。结果表明:矿石颗粒级配性越好,矿堆孔隙率越低;矿石粒径越均匀,矿堆不同区域孔隙率差异越小;矿石粒径分布对孔隙尺寸和连通性影响较为显著,对孔喉形状因子影响较小。随着细颗粒矿石的减少,大孔隙增多,孔喉半径、喉道长度和孔喉体积相应增大;随着矿石粒径均匀性的增加,堆浸体系中孤立孔隙所占比例减少,高配位数孔隙所占比例增大,即矿堆内的孔隙空间具有更好的连通性。

     

    Abstract: Heap leaching is a widely used solution mining technology that enables various kinds of low-grade ores to be processed economically. The solution flow characteristics are very important factors in the leaching process, and they influence both the overall recovery and kinetics of the system. The properties of fluid flow in porous media are associated with the pore structure, which is influenced by the grain size and shape. To study the influence of ore particle size gradation on the pore structure of the heap leaching system, a micro-CT scanning test was conducted in ore columns with two grain size gradation types, and images of the internal structure of the leaching columns were obtained. A 3D digital pore model of the two leaching columns was then established, and the spatial distribution characteristics of 2D and 3D porosity were analyzed. The pore network models of the two columns were then extracted from the reconstructed 3D binary pore structures using the maximal ball fitting method, and the effect of the ore particle size distribution on the pore throat radius, throat length, pore throat volume, shape factor, and coordination number was analyzed. The results show that the porosity of the column comprising well-graded ore particles is lower than the column with uniformly graded grains. In addition, the 2D and 3D porosities of the well-graded ores show a relatively high degree of heterogeneity compared to those of the more uniformly graded ores. The ore particle size gradation has a significant influence on pore size and pore connectivity, but it has a minimal influence on the pore throat shape factor. The number of large pores increases with a decrease in the amount of fine ore, and the pore throat radius, throat length, and pore throat volume also correspondingly increase. When the uniformity of ore particle gradation is enhanced, the proportion of isolated pores decreases and the proportion of the number of high coordination pores increases.

     

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