Coal mine drainage resources utilization technology innovation

The resource utilization of coal mine drainage has been attracting growing attention. The increasingly stringent discharge standards and the deepening of the concept of intelligent mine have posed new challenges to mine water treatment technology. This paper discussed the traditional treatment processes and the multi-stage filtration underground treatment technology. In addition, a new high-efficiency technology-Polycera membrane ultrafiltration-was proposed to treat coal mine drainage on the basis of summarizing the existing technology problems. Compared with the multi-process of the traditional treatment technology, the new technology only includes two main units, high pressure pretreatment and atmospheric filtration treatment, because the treatment process does not need dosing and the whole dosing system can be omitted, which solves the problem that the traditional coal mine drainage treatment method must add coagulant, and can truly make the whole process of coal mine drainage treatment unattended and meet the requirements of the intelligent mine. The new technology offers the advantage of a shorter process flow and a smaller footprint and could ensure the stability of effluent water quality. Besides, the new technology could be operated automatically without chemical additions. At the same time, it can realize modularization and intellectualization, and can be applied to the direct filtration of coal mine drainage containing high suspended solids in different scenarios, or as the pretreatment unit of coal mine drainage brackish water, especially suitable for the in-situ reuse of coal mine drainage underground treatment. The core component of the new technology is the Polycera membrane with high strength and high-water flux. It is a super hydrophilic and oleophobic material that can withstand suspended solids (SS) of high concentrations up to 10 000 mg/L. By analyzing the laboratory-scale test results and the reconstruction engineering case of coal mine drainage treatment on the ground, it can be seen that in the range of inlet SS of 0-10 000 mg/L, the SS of the filtered effluent after direct filtration with Polycera membrane can be stably below 1 mg/L, and the turbidity can be stably below 1NTU, it is shown that the new technology presents apparent advantages in the resource utilization of coal mine drainage. This technology could provide a technical reference for large-scale engineering applications in the future. © 2023 Coal Science and Technology. All rights reserved.