Decarbonization Pathways in Underground Mining in Cold and Arctic Climates: A Review of Heat Recovery Systems with Case Studies in Canada

In cold climates, mine air conditioning systems are essential for preventing liners and shaft components from freezing. Traditionally, fossil fuel burners are used to heat intake air, resulting in high energy consumption and significant greenhouse gas emissions. As part of efforts to reduce both environmental impacts and energy use, mining companies are increasingly adopting innovative solutions, such as heat recovery systems. These systems offer a promising approach to significantly reduce energy demand for underground mine heating. This study evaluates several heat recovery technologies including exhaust air, water, hybrid exhaust air–water, diesel exhaust, jacket water, and hybrid diesel exhaust–jacket-water systems, through numerical modeling. Two case studies are presented: a grid-connected mine in British Columbia with moderately cold conditions, and an off-grid mine in the Northwest Territories, which experiences Arctic climate extremes. Results show that heat recovery can reduce heating costs by up to 89% in British Columbia and as much as 90% in the Northwest Territories, depending on the system applied. The findings also demonstrate substantial associated carbon emission reductions. Furthermore, a comprehensive feasibility analysis was carried out to evaluate the thermodynamic performance, financial savings, and carbon emission reductions of these systems across various mining operations, offering a preliminary assessment of their potential for mining settings.