Coal mining in China is facing the transition from output to quality. Based on the total mining capacity and average production, the current situation of coal mining at mine, city, and province levels is analysed, and data in support for the layout of sustainable mining development and the optimization of output provided. The results show that 87% of China's coal is mined by underground methods, with an average production capacity of 0.93 Mt/a per mine. Open pit mining accounts for 13%, with an average mine production capacity of 5.73 Mt/a. The average mining capacity of coal mines in China is 1.05 Mt/a, with 1181 coal mines with an average capacity less than 0.3 Mt/a, accounting for 35% of the total coal mines but contributing only 4.51% to output. They are distributed in about 48 cities in six provinces, seriously restricting the transition to green coal mining. The coal industry should speed up the closure of small coal mines in key provinces and cities, eliminate outdated production capacity in the central region, increase the speed and proportion of coal resources moving westward, and promote high-quality development of coal mining.
28 August 2019 in Geotechnical and Geological Engineering
Green mining is the basic background of high-quality mining, and source reduction is the most important part, among which the optimization of working face height and length is the most active. How to control the working face parameters, reasonably evaluate the surface subsidence characteristics of the super-long working face, and identify the limit working face length and the surface discontinuous deformation threshold is particularly important. In order to solve the problem of irreversible damage to the surface caused by the mining process of the working face, this paper discusses the whole process of surface movement in the 8.8 m super-large mining height working face of Shangwan Coal Mine through field investigation, the maximum subsidence is 6.20 m, with a subsidence coefficient of 0.72. Combined with the inflection point trajectory, advancing degree and subsidence coefficient, the 0.9 coefficient of the working face subsidence basin boundary and the loss reduction strategy far from the limit working face threshold are proposed. The results show that the subsidence basin of 12,401 working face accounts for 34%, the continuous deformation area of surface accounts for 64%, and the influence area of discontinuous deformation area is within 10 times of mining height. With the help of borehole detection verification, the caving zone height within the coal seam overburden to be between 33.2 and 33.25 m and the fracture zone height between 118.08 and 132.83 m. Therefore, the caving ratio is about 3.8, and the fracture ratio is about 13–15, which provides a strong basis for the optimization design of working face and the timing of surface ecological management.
22 December 2025 in Geomechanics and Geophysics for Geo-Energy and Geo-Resources
In high-intensity mining operations in western China, shallow burial depths and rapid advancement rates induce rapid surface responses, significant deformation, and pronounced crack development. This study comprehensively evaluates these effects through full-process rock movement monitoring at the Jinjie coal mine, focusing on subsidence coefficients, mining coefficients, and inflection point trajectories. Results indicate that weak stability of the overlying strata in the shallow-buried working faces led to substantial surface subsidence, with a subsidence coefficient of 0.87, exceeding typical values (0.6–0.7) for conventional mining. The inflection point at the open-off cut followed a monotonic L-shaped trajectory, migrating laterally up to 4.7 times the mining height (15 m), while the inflection point near the roadway stabilized at 5.6–7.5 times the mining height (18–24 m) after two fluctuations. A significant contrast was observed in the horizontal movement coefficient between the goaf area (0.21–0.47) and the unmined area (1.59–2.38). Surface cracks exhibited an O-shaped ring distribution, synchronizing with periodic weighting intervals of 12–14 m; the pressure coefficient was approximately 1.73. Despite pronounced crack development, self-healing mechanisms reduced environmental risks. Full surface subsidence was achieved after the working face had advanced 320 m, a distance approximately equal to 1.24 times the working face length and 3.5 times the burial depth, with the basin areas occupying 48% of the total. Surface stabilization was achieved within 70 days (less than the ratio of burial depth to 100 m), underscoring the necessity of proactive measures such as crack filling to prevent air leakage and water inrush during rapid advancement (20 m/day).
Green mining is the basic background of high-quality mining, and source reduction is the most important part, among which the optimization of working face height and length is the most active. How to control the working face parameters, reasonably evaluate the surface subsidence characteristics of the super-long working face, and identify the limit working face length and the surface discontinuous deformation threshold is particularly important. In order to solve the problem of irreversible damage to the surface caused by the mining process of the working face, this paper discusses the whole process of surface movement in the 8.8 m super-large mining height working face of Shangwan Coal Mine through field investigation, in-situ monitoring and data analysis. Combined with the inflection point trajectory, advancing degree and subsidence coefficient, the 0.9 coefficient of the working face subsidence basin boundary and the loss reduction strategy far from the limit working face threshold are proposed. The results show that the subsidence basin of 12401 working face accounts for 34%, the continuous deformation area of surface accounts for 64%, and the influence area of discontinuous deformation area is within 10 times of mining height. With the help of borehole detection verification, the time effect of rock movement in different layers is further revealed, which provides a strong basis for the optimization design of working face and the timing of surface ecological management.
As a controllable active resource in China, coal mining is facing the transition from output to quality. Base d on the total mining production and average capacity, the current situation and level of coal mining at three scales of mine, city and province is analyzed , data support for the layout of sustainable mining development and the optimization of output is provided. The results show that China's coal is mainly mined by underground mining, accounting for 87%, with an average production capacity of 0.93 million tons. Open pit mining accounts for 13%, with an average production capacity of 5.73 million ton s. S o t he average production capacity of open pit and underground workers is 1.045 million tons, with 1,181 coal mines capacity lower than 0.3 million tons, accounting for 35% of the total coal mines, contributing only 4% to their output. They are distributed in about 48 cities in 6 provinces, seriously restricting the green coal mining. The coal industry should speed up the reduction of small coal mines in key provinces and cities, eliminate outdated product ion capacity in the central region, increase the speed and proportion of coal resources moving westward, and promote high quality development of coal mining.