东部草原区露天煤矿减损开采与生态系统修复技术及应用

Technology and application of damage reduction mining and ecosystem restoration of open-pit coal mines in eastern grassland area

东部草原区是我国重要的煤能源基地,煤炭开发为东北区能源保供和我国经济发展做出了巨大贡献。东部草原区气候酷寒干旱、土壤瘠薄、植被抗扰动能力低,而煤炭大规模开发导致了当地草原退化和水位下降等问题,因此开展了东部草原区露天煤矿减损开采与生态系统修复研究,提出了露天煤矿源头减损-过程控制-末端治理的生态修复理念,研发了开采节地减损、物料跨时空调配储用和“生态窗口期”协同修复等技术,并在胜利露天矿和宝日希勒露天矿进行技术应用和示范。结果表明:胜利露天矿原排土工作帮坡角提高了2.9°,可开展生态修复时间提前0.9 a,采场占地面积缩小75.2 hm^(2);仅在宝日希勒露天矿南帮实施冻结期靠帮开采-快速回填技术多回收煤炭资源69.55万t,占年生产能力的2%,在满足露天矿生产能力的前提下少征地2.4 hm^(2)/a。研究成果为相似露天矿开展减损开采与生态修复工作提供了技术支撑,具有广泛的应用和推广价值。

The eastern grassland region is an important coal energy base in China, and coal development has made great contributions to the energy security supply of the northeast region and the economic development of China. In response to the problems of cold and arid climate, thin soil and low vegetation disturbance resistance in the eastern grassland area, and the large-scale development of coal has led to the degradation of the local grassland and the decline of water level, we have carried out research on the loss reduction mining and ecosystem restoration in the eastern grassland area, put forward the ecological restoration concept of loss reduction at the source-process control-end treatment in the open pit coal mine, and developed the technologies of loss reduction by mining, material deployment and storage across time and space, and “ecological window” collaborative restoration. The research has developed the technologies of mining loss reduction, inter-temporal material deployment and storage, and “ecological window” collaborative restoration, and has been applied and demonstrated in the shengli open pit mine and baorixile open pit mine. The results show that: the slope angle of the original drainage work gang of the shengli open pit mine has been increased by 2.9° and the ecological restoration can be carried out 0.9 years earlier, and the area covered by the quarry has been reduced by 75.2 hm^(2);only in the south gang of the baorixile open pit mine, the implementation of the freeze-period mining-rapid backfill technology has recovered 695 500 tons more coal resources, accounting for 2% of the annual production capacity, and 2.4 hm^(2)/a less land acquisition while meeting the production capacity of the open pit mine. The results of the study provide an opportunity for similar open-pit mines to reduce the amount of coal resources. The research results provide technical support for similar open pit mines to carry out damage reduction mining and ecological restoration work, and have wide application and promotion value.