Ecological-Based Mining: A Coal–Water–Thermal Collaborative Paradigm in Ecologically Fragile Areas in Western China

Abstract

A substantial reduction in groundwater level, exacerbated by coal mining activities, is intensifying water scarcity in western China’s ecologically fragile coal mining areas. China’s national strategic goal of achieving a carbon peak and carbon neutrality has made eco-friendly mining that prioritizes the protection and efficient use of water resources essential. Based on the resource characteristics of mine water and heat hazards, an intensive coal–water–thermal collaborative co-mining paradigm for the duration of the mining process is proposed. An integrated system for the production, supply, and storage of mining companion resources is achieved through technologies such as roof water inrush prevention and control, hydrothermal quality improvement, and deep-injection geological storage. An active preventive and control system achieved by adjusting the mining technology and a passive system centered on multi-objective drainage and grouting treatment are suggested, in accordance with the original geological characteristics and dynamic process of water inrush. By implementing advanced multi-objective drainage, specifically designed to address the “skylight-type” water inrush mode in the Yulin mining area of Shaanxi Province, a substantial reduction of 50% in water drillings and inflow was achieved, leading to stabilized water conditions that effectively ensure subsequent safe coal mining. An integrated-energy complementary model that incorporates the clean production concept of heat utilization is also proposed. The findings indicate a potential saving of 8419 t of standard coal by using water and air heat as an alternative heating source for the Xiaojihan coalmine, resulting in an impressive energy conservation of 50.2% and a notable 24.2% reduction in carbon emissions. The ultra-deep sustained water injection of 100 m³·h⁻¹ in a single well would not rupture the formation or cause water leakage, and 7.87 × 10⁵ t of mine water could be effectively stored in the Liujiagou Formation, presenting a viable method for mine–water management in the Ordos Basin and providing insights for green and low-carbon mining.