周伟, 时旭阳, 李明, 陆翔, 栾博钰. 露天矿坑隔水层重构及泥岩-地聚合物损伤渗透特性[J]. 煤炭学报, 2020, 45(10): 3556-3562. DOI: 10.13225/j.cnki.jccs.2019.0983
引用本文: 周伟, 时旭阳, 李明, 陆翔, 栾博钰. 露天矿坑隔水层重构及泥岩-地聚合物损伤渗透特性[J]. 煤炭学报, 2020, 45(10): 3556-3562. DOI: 10.13225/j.cnki.jccs.2019.0983
ZHOU Wei, SHI Xuyang, LI Ming, LU Xiang, LUAN Boyu. Reconstructed water-blocking layer in open-pit mine and the damage-permeability characteristics of mudstone-geopolymer[J]. Journal of China Coal Society, 2020, 45(10): 3556-3562. DOI: 10.13225/j.cnki.jccs.2019.0983
Citation: ZHOU Wei, SHI Xuyang, LI Ming, LU Xiang, LUAN Boyu. Reconstructed water-blocking layer in open-pit mine and the damage-permeability characteristics of mudstone-geopolymer[J]. Journal of China Coal Society, 2020, 45(10): 3556-3562. DOI: 10.13225/j.cnki.jccs.2019.0983

露天矿坑隔水层重构及泥岩-地聚合物损伤渗透特性

Reconstructed water-blocking layer in open-pit mine and the damage-permeability characteristics of mudstone-geopolymer

  • 摘要: 露天矿水资源保护与恢复是煤炭露天开采面临的重大环境问题,是制约露天煤矿大规模发展的重要因素。露天开采形成漏斗效应,对周边地下水资源破坏严重且难以恢复,根本原因是煤层以上隔水层被爆破剥离,隔水层缺失;内排物料结构松散,渗透系数大,达不到隔水、阻水的效果。目前针对恢复与保持露天矿水资源问题,鲜有系统研究及有效措施。因此研究团队提出,以泥岩-地聚合物材料构建露天矿内排土场重构隔水层,将露天矿山及周边工业固体废弃物纳入隔水层原材料选材范畴,在实现构建隔水层的同时,消耗大量工业废渣,形成以露天矿山为中心的工业生态圈。低渗透率是隔水层材料基本特征,其数值应在10-15 m2以内。重点考察了材料损伤渗透特性。以地聚物缩聚反应为理论基础,采用泥岩、矿渣、赤泥作为碱激发粉体材料,采用标准砂作为细骨料材料,水玻璃为激发剂,制备得到标准(50 mm×100 mm)泥岩-地聚合物试样。定义了一维应力条件下,以单轴加载水平为指标的损伤变量,通过渗透试验分析了不同损伤程度条件下材料渗透特性。结果表明,低损伤(当σ/σc<0.3时)情况下,材料并未出现贯通裂纹,导致渗透介质未能穿过材料,所以未能采集到数据;随损伤的增大(当σ/σc≥0.3时),试样的原始空隙与微裂纹迅速扩展、贯通,应力卸载后贯通裂纹不闭合,导致渗透率的急剧增大,且数量级介于10-16~10-15 m2。通过线性与指数2种形式拟合试验结果,确定了本试验条件下损伤变量指数n=6,损伤变量Dσ与渗透率k呈典型非线性关系。泥岩地聚合物材料,在无损伤至破坏全过程中,其损伤-渗透性能满足构建重构隔水层对渗透率要求。为实现永久隔水目的,应当关注其长期渗透性能,以及在地下水环境中是否释放重金属离子等污染性物质,研究团队将针对以上方面内容继续开展研究。

     

    Abstract: The major environmental problem in open pit coal mining is water conservation and restoration,which re- stricts the large-scale development of open pit mines. The surrounding groundwater resources are severely damaged by the funneling effect formed in mining process,which is difficult to recover. The reasons are demonstrated as follows:the water-blocking layer above coal seam is missing due to stripping;the material loose in structure in the inner dump is characterized by a large permeability,which does not achieve the effect of water blocking. At present,there is little sys- tematic research and effective measures for restoring and maintaining open-pit mine water resources. This paper propo- ses a reconstructed water-blocking layer based on mudstone polymer composed by the solid wastes in open-pit mines and surrounding industrial areas. With the realization of the construction of the water-blocking layer,a large amount of industrial waste is consumed, forming an industrial ecosystem centered in open pit mines. Low permeability within 10-15 m2 is the basic feature of the water-blocking material. Alkali-inducing powder materials (Mudstone,slag and red mud), fine aggregate material ( standard sand), and activator ( sodium silicate ) were used to prepare standard (ϕ50 mm×100 mm) mudstone-geopolymer samples. The damage permeation characteristics of materials are investiga- ted in this research. The damage variable Dσ is measured by uniaxial loading. The permeability characteristics under different damages are analyzed through experiments. The results show that under low damage (σ / σc

     

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