Coal is an important resource that has supported China’s economic development. This situation is expected to continue in the immediate future. However, coal mining has also led to serious environmental disasters in some mining areas. Henan Province is one of the 14 large-scale coal bases that are planned by the Chinese state. It is located in the transitional zone between the second and third terrain ladders of China and spans two tectonic units. The geological features and ecological environmental characteristics display wide spatial variations throughout this district, which is an ecologically fragile region of stepped transition type. However, large-scale, extremely intense coal mining activities will inevitably lead to further deterioration of the already fragile ecological and geological (eco-geological) environment, which makes recovery increasingly difficult. Based on the condition of the eco-geological environment and the coal mining industry in the Henan mining area, the mechanisms by which mining-induced damage can occur were analyzed. The characteristics and status of the destruction of ground structures, land resources, water resources, the atmospheric environment, and natural ecology are discussed in this paper. Appropriate mitigation measures are proposed based on the findings. This mainly includes: management practices to prevent and mitigate damage throughout all stages of mining; adoption of mining techniques that will control damage at the source; and, the adoption of appropriate post-mining recovery technologies. The analysis of mining-induced eco-geological environmental damage and mitigation measures is of importance for the prevention of eco-geological disasters, and the promotion of efficient and environmentally sustainable exploitation of coal resources.

As coal resources trapped under surface buildings in the Wangtaipu coal mine area impede the efficient mining of coal seams and constrain the sustainable development of coal mines, a super-high-water roadway backfill mining technique for preventing building damage was adopted. According to the control principle and theoretical calculations, an engineering design was established including the reasonable width of segment coal pillars in the working face and technical parameter design. The monitoring results after the implementation of the scheme showed that building deformation was controlled within grade I, protecting the surface buildings. A reasonable roadway design parameter was achieved, with a surface subsidence of 27 mm and horizontal deformation of 0.3 mm/m, indicating that it can ensure the safety of surface buildings from the State Bureau of Coal Industry. The practical trial can provide a reference for the extraction of coal resources under similar conditions and is vital for the sustainable development of the mining industry and economic growth.

In the ecologically fragile mining area of northwest China, high-intensity mining has seriously affected the aquifer and surface eco-environment. In order to better implement water-preserved mining in ecologically fragile areas, the aquifer failure characteristics should be first detected accurately; therefore, it is necessary to find a convenient and fast detection method. Based on the analysis of the basic principles and influencing factors of the magnetotelluric (MT) method, the feasibility of using the MT method to detect aquifer failure is verified by testing the mined area with MT detection and field borehole measurement. Subsequently, the failure characteristics of overburden and unconsolidated aquifers under high-intensity mining are studied by MT detection and physical simulation. By comparing the physical simulation with the field measurement from the aspects of the maximum surface subsidence, interval of periodic weighting and step cracks, the reliability of the height of the water flowing fracture zone and caving zone obtained from physical simulation is verified. The analysis from MT detection and physical simulation shows that the results of the two methods are in accord with each other, which further confirms that the MT method can be used to detect the failure of overburdened structures and aquifers. The penetrating fractures are the main channel for the downward seepage of water resources, which is caused by the “two-zone” of overburden model and located in the “dimple” shape in the apparent resistivity (AR) isogram. It can provide a reference and technical support for the corresponding new water-preserved mining technology and the construction of digital mines.

Mining fracture is the key factor in realizing water-conservation mining, stability evaluation of coal mining subsidence areas, and accurate restoration of the surface eco-environment. To clarify, the evolution and distribution of mining fractures, based on the key strata theory and the mining degree of overburden failure, the contact state of rock stratum after overburden critical failure was analyzed, the formation mechanism of “saddle shaped” water conducting fracture zone was revealed, and the permanent mining fractures were determined to be primarily concentrated in the overburden structure at the boundary of the working face. According to the shear test of sandstone in the fracture zone, the damage degree of the rock sample was positively correlated with shear stress, and the overburden structure exhibited no instability. Based on the distribution of mining fractures, the fracture zone was divided into the original fracture, tensile fracture, structural void, and void compaction areas in the horizontal direction. The structural void area had the largest residual deformation in the goaf. A regional division method based on overburden critical failure was proposed and applied in engineering by using surface movement monitoring. The results showed that the surface subsidence near the boundary of working face was greater than that in the middle, and the residual surface deformation in the goaf was closely related to the mining time, which has long-term characteristics. The rationality of the regional division method of mining fractures was also verified.

Traditional cemented paste backfilling continues to face the shortcomings such as paste leakage, poor adaptability to geological structures and insufficient roof-contact. To solve the limitations, a novel L-shaped cemented paste backfilling (LCPB) technology was proposed in this study. It is to set L-shaped filling zones and partition zones in the goaf to perform interval and multiple filling. A mechanical model was established to calculate backfilling body strength, widths of L-shaped filling zones and partition zones and backfilled ratio and etc. The results of a case study showed that: (1) The LCPB mining has a high backfilled ratio, without prominent ground pressure. The maximum values of roof-to-floor convergence of the working face and roadway were 58 mm and 259 mm, respectively. It could effectively control the deformation of surrounding rock and achieve roadway retention. (2) When the floor strata were intact, the maximum floor damage depth was less than 4 m, and the floor near the fault was 10–12 m. The secondary lift height of the confined water was about 5 m near the fault. The LCPB mining allows for safety mining above a confined aquifer. (3) The maximum surface inclination and curvature were 1.75 mm/m and 0.06 mm/m², respectively. The draw angle was 11.3°, and the subsidence factor was 0.085. The ground surface deformation was reduced to be less than that allowed in the first level of the building damage (inclination and curvature of 3 mm/m and 0.2 mm/m², respectively).

The gases released by underground coal mining pose a threat to mine safety, lead to resource wastage, and contribute to environmental pollution. Employing long horizontal boreholes (LHB) for gas extraction proves to be an effective solution. However, accurately determining the LHB's position within the overlying rock strata is challenging due to complex mining and geological conditions. This study introduces a novel “zone‐position” method for identifying the optimal LHB placement, utilizing both physical simulation tests and theoretical analysis. The approach comprises two steps. Initially, it identifies the appropriate LHB layout zone within the overlying strata. It delineates four subzones within the fractured zone, among which the stable fractured subzone (SFSZ) is identified as the most favorable for LHB placement. The boundaries of the SFSZ are also defined. Subsequently, the method focuses on pinpointing the LHB's precise location within the SFSZ, proposing a criterion that considers gas accumulation, strata permeability, and LHB stability. Application of this method in engineering projects demonstrates that the gas extracted by LHBs accounts for about 60% of the total gas emission. Furthermore, the volume of gas extracted at the optimal LHB location reaches up to 5.52 m³ min⁻¹, triple that of other locations.