Mine environmental restoration and management model

2) Local collapse pit backfill: The collapse pit developed in the subsidence basin to be repaired in Baolixile mining area is backfilled with mine solid waste and the surface is leveled to keep the topographic relief consistent with the surrounding area. Backfill materials come from Shenbao open-pit dump, mainly gangue and gravel soil, which can not only backfill the collapse pit, but also make good use of mine solid waste. After backfilling the collapse pit, cover its surface with 30cm thick cultivated soil in order to restore vegetation.

3) Development of constructed wetland: The treatment project of Baolixile Mining area retains the ground collapse area with accumulated water, or further digs the surrounding deep collapse pit, and builds the stagnant water depression formed by digging deep and shallow into a drinking point for livestock and a fish pond. As shown in Figure 6, the treatment effect of the subsidence basin in Baolixile Mining area is as follows: In other areas where the restoration target is grassland, after the restoration of the basic terrain, the topsoil and cultivated soil are repeated on the surface, and grass seeds suitable for local growth such as Leymus chinensis, dipweed and artemisia cold are mixed and planted.

6.2.4 Restoring the Effect of the governance Mode

Baolixile Mining area adopts the method of deep excavation and shallow treatment for the ground collapse area with accumulated water, and uses the excavated lake mud as the cultivated soil for the adjacent collapse pit and the shallow area after treatment to cover the soil and grass, so as to rationally utilize the land resources in the ground collapse area, improve the local ecological environment of the collapse pit, make the environment of the problem restoration area more beautiful, and develop the animal husbandry in the mining area. By using the solid waste of the mine dump to backfill the subsidence pit developed in the subsidence basin, the mine solid waste is effectively used and the influence of the subsidence pit is eliminated. After treatment, the ecological environment in the sunken basin is basically restored and integrated with the surrounding environment. The constructed wetland has a good adaptability to the local climate, and can store natural precipitation and provide some water for the animal husbandry and fishery in the mine.