| 摘要: |
| 铜尾矿的大规模堆存和矿山修复中优质客土的不足已成为矿山企业面临的两大难题。为了同时解决以上问题，以某铜尾矿为研究对象，基于“以废治废”的理念，通过对尾矿添加石灰、土壤改良基质、微生物菌剂、磷肥、复合肥进行掺混改良，改善其返酸、重金属毒性和寡营养等不利植物生长条件，并将改良尾矿替代优质客土用于尾矿库库坝的生态修复，实现生态化利用。结果表明：野外试验实施三个月后，改良后的尾矿理化性质得到较好的改善；试验区域植被恢复效果显著，整体覆盖度高达96%，生物多样性高，已记录的植物品种达到16种；铜尾矿利用的掺混比例达到93%。该试验成果有助于大量堆存铜尾矿的综合利用，并可为粤港澳大湾区同类矿山的生态环境保护工作提供一定的思路。 |
| 关键词: 铜尾矿 基质改良 生态修复 生态化利用 |
| DOI：10.7515/JEE222086 |
| CSTR： |
| 分类号: |
| 基金项目:广东省重点领域研发计划（2019B110207001）；广东省乡村振兴战略专项（200716106270603）；韶关市科技计
划项目（220716096270196） |
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| Research on mine remediation technology based on ecological utilization of copper tailings |
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MAO Zhe1, 2, YANG Taotao1, 2*, ZHANG Jintao1, LIAO Bin3
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1. Guangdong Jiangtong Taolin Eco-Environmental Co., Ltd., Shaoguan 512000, China
2. Guangdong Heavy Metal Mine Ecological Restoration Engineering Technology Research Center, Shaoguan 512000, China
3. School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
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| Abstract: |
| Background, aim, and scope The disposal of massive amounts of mine tailings has remained a major challenge for the mining industry in China. Thus, it is urgent to find a suitable way to reuse these mine wastes. On the other hand, there is often a lack of high-quality external soil for mine rehabilitation. While mine tailings have potential as a alternative, the feasibility in practical implementation has not been systematically investigated. To this end, we have collected tailings from a copper mine. Lime, soil amendments, microbial agent, phosphate fertilizer and compound fertilizer were added to improve the physiochemical properties and nutrient conditions. The effectiveness of using these improved tailings as a substrate in the ecological restoration of degraded mine lands was evaluated in a field revegetation test in a tailings pond. Materials and methods Firstly, a simple pot experiment was carried out in the laboratory. Lime, soil amendments, microbial agent, phosphate fertilizer and compound fertilizer were added to improve the copper tailings, and the composition and dosage of these improvement materials were preliminarily confirmed. In order to further verify the feasibility of using the improved tailings as a substrate for plant growth, a field pilot test was carried out in a tailings impoundment, and the changes of physical and chemical properties of tailings and the growth of plants were investigated three months after revegetation. Results The results of the three-month experiment demonstrated a feasibility of ecological utilization of the mine tailings. Specifically, the physical and chemical properties of the modified tailings were significantly improved, with an apparent increase of pH (approaching a neutral value) and a reduction of electrical conductivity by 68.3%. Meanwhile, the acid production potential of the tailings was effectively controlled. The concentrations of available Pb, Zn, Cu and Cd decreased by 64.4%, 71.1%, 78.4% and 70.0% respectively and the contents of organic matter, total phosphorus and total nitrogen was 12.0, 4.4 and 4.6 times of that before the revegetation. Moreover, the effect of revegetation was remarkable, with an overall plant coverage reaching up to 96%, exhibiting a high plant biodiversity (16 plants species recorded). Discussion Compared with the original tailings, the physical and chemical properties of the tailings after three months of restoration were significantly improved, mainly due to the addition of improvement materials such as lime, soil amendment, microbial agent, phosphate fertilizer and compound fertilizer. The decline in the available heavy metals is significant, which is likely attributable to the large amounts of calcium ion, phosphate and organic substances contained in the improvement materials. Meanwhile, plant fixation could also be an important reason for the decrease in the content of available heavy metals. The results of the plant survey after the three-month field test demonstrated an apparent effect of revegetation, achieving an overall plant coverage of as high as 96%. Notably, different plant species exhibited marked difference in growth in the process of ecological restoration of tailings. This is mainly related to their adaptability to the tailings environment and heavy metal tolerance. Future efforts screening plant species with a high tolerance and adaptability can help improve the effectiveness of tailings restoration. Conclusions The application of lime, soil amendment, microbial agent, phosphate fertilizer and compound fertilizer has demonstrated a good improvement effect on the physical and chemical properties of the copper tailings, which can subsequently serve as a good substrate for the ecological restoration of tailings ponds. Meanwhile, through the field experiment, a set of cost-effective restoration technology schemes for the revegetation of tailings impoundments has been developed. Recommendations and perspectives The results of this study are helpful to the comprehensive utilization of large amounts of tailings in the revegetation of mine degraded lands. |
| Key words: copper mine tailings substrate amendment ecological restoration ecological utilization |
