Green and efficient water conservation mining technology in shallow and strongly water-rich areas

The western region is rich in coal seam resources, and the intensity of mining is high. Traditional mining methods can easily lead to the loss of water resources in aquifers, resulting in serious water shortage problems. Therefore, researching water conservation mining technology in shallow-buried strong water-rich areas is of great significance for ensuring water resource safety, maintaining ecological balance, and promoting economic development. By controlling the movement of rock strata to maintain the stability of aquifers, developing cost-effective and widely applicable water conservation mining technologies and materials, a green and efficient three-dimensional water conservation mining system for coal seams in shallow-buried strong water-rich areas can be formed, achieving dual goals of coal mining and water resource protection. This paper first analyzes the current situation and difficulties of water conservation mining, compares existing technologies from aspects of technological advancement and safety, and conducts in-depth research on materials, equipment, and processes, summarizing and analyzing the applicable conditions of different technologies. Then, taking the Jinjie coal mine as an example, based on the water conservation coal mining plan and the actual measured height of the water-conducting fracture zone, the mining field is divided into regions, proposing the principle of regional classification management. Innovatively, the paper proposes the technology of remaking the bottom water-blocking layer of the quaternary loose water-rich layer before mining, forming an effective isolation, achieving coordinated development of coal mining and water resource protection, and protecting natural topography and surface vegetation. At the same time, in response to the inefficiency of the current comprehensive mining frame back paste filling and the inability of the support to flexibly switch between filling and non-filling, a new type of filling and non-filling dual-use support is designed and proposed. It can be used as a filling support and can also be used for the disassembly of the rear support, installing the side protection plate of the protective beam, meeting the needs of ordinary support use, and improving the efficiency of equipment use. Finally, the paper summarizes the technology of grouting repair and transformation of the top of the water-conducting fracture zone after mining and the evaluation of grouting effects, and illustrates it with the application of the Jinjie coal mine. It has a wide guiding significance for similar conditions of coal seam mining in the Ordos Basin and provides important support for green mining in the coal industry. © 2024 China Coal Society. All rights reserved.