Thoughts on roadway and chamber construction technology in deep rock for mineral–geothermal co-mining

With the depletion of shallow mineral resources, China’s mineral mining is gradually developing into deep rock mining, which will become an important source of mineral resources in China. The mineral – geothermal co-mining technology can reduce the heat disaster and utilize the geothermal resources simultaneously, thus being a deep mining technology with wide applications in the future. The co-mining of deep mineral and geothermal energies is an important means to ensure the sustainable utilization of deep resources. However, the construction of deep roadways and chambers faces many new challenges and technical issues. High temperature and stress are the two major characteristics of deep rock, causing completely different mechanical characteristics of deep strata to those of ordinary strata. Technical solutions are required to resolve these two problems in the development of mineral–geothermal co-mining. This study analyzed the strategic position and significance of roadway and chamber construction in deep high-temperature strata and introduced the basic theory of roadway and chamber construction technology in a deep high-temperature environment. Current research is insufficient for application in practical engineering; thus, in the future, diagenetic rock characteristics of rocks under high temperatures should be studied, and the stress–strain characteristics of deep strata under multifield coupling should be described. Targeting the problems of heat disaster and surrounding rock stability control in the construction of deep roadways and chambers, this study summarized and introduced the existing techniques and analyzed the shortcomings in the construction of deep roadways and chambers with co-mining. The traditional deep roadway and chamber construction technology does not fully utilize the resources and fails to provide enough safety guarantees. The construction of deep roadways and chambers should understand the obscure fundamental, physical, and mechanical properties of rock under high temperature and stress and deal with the backward control technology of surrounding rock stability. In addition, new technologies and materials should be used to improve the utilization rate of geothermal energy and achieve carbon neutralization. Finally, establishing a technical system for fine geological survey, optimization of surrounding rock cooling and stability control technology, and roadway and chamber risk monitoring is discussed in this paper.