浸出过程中矿石颗粒表面微孔裂隙演化规律

Evolution rules of micropores and microfracture on surface of ore particles in heap leaching

为揭示矿石表面微孔裂隙在溶浸液作用下的响应机制,以羊拉碱性氧化铜矿堆浸为工程背景,借助光学显微镜和扫描电镜开展浸出前后矿石表面微形貌演化试验研究。在微孔裂隙发育特征研究的基础上,分析酸浸环境下矿石表面微形貌损伤机制。根据分形几何理论,对矿石表面微孔裂隙演化规律进行分形描述。研究表明:随着浸出时间增加,孔隙分形维数和孔隙率变大,裂隙信息维数也变大,证明可用分形维和信息维表征不同浸出阶段矿石表面不均匀性和复杂程度。同时,Ca,S及Fe等元素会形成结晶物沉淀填充在矿石微裂纹、细微孔隙及晶粒表面,阻塞渗流通道,减缓微孔裂隙进一步扩展或延伸。

To reveal the response mechanism of surface micropores and microfracture to the action of leaching solution,dump leaching of alkaline oxide copper ore in Yangla was chosen as the analysis object.Experimental research on microtopography evolution of ore surface was carried out with optical microscopy and scanning electron microscopy.Based on the developmental characteristics study of micropores and microfractures,microtopography damage mechanism was analyzed in the environment of acid leaching.Fractal geometry was applied to describe the evolution rules of surface micropores and microfracture.The results show that the pore fractal dimension and porosity are greatened;fracture information dimension also becomes larger,as leaching time increases.Inhomogeneity and complexity of ore surface in different leaching stage can be characterized by fractal dimension or information dimension.Meanwhile,crystals precipitation such as Ca,S and Fe filled in microcracks,porosity and grain surface,results in obstruction of seepage channel,slowing down the further expansion or extension of micro-pores and micro-fractures.