A novel chemical CO removal method in mines: Theoretical model and experimental

Diesel-powered vehicles, blasting operations, spontaneous coal combustion, external fires, and gas or coal-dust explosions are the primary sources of carbon monoxide (CO) in underground mines. These sources frequently trigger CO volume fraction over-limit alarms, posing serious threats to underground mines safety. At present, respiratory protection and mechanical ventilation are the main approaches for CO control. However, they merely isolate personnel from CO or dilute their volume fraction rather than actively removing it. As a result, their emergency removal efficiency and response capability are limited, making it difficult to achieve intrinsic elimination of CO hazards. Since 2017, our research team has pioneered a novel chemical CO removal method for underground mines, achieving a series of breakthroughs in material development, theoretical modelling, equipment design and engineering applications. Based on the previous research results, the connotation of the "source-based governance and environmental adaptation" technology for the CO chemical removal technology in underground mines is systematically presented. Three key performance metrics, namely CO removal efficiency, CO removal rate, and total CO removal amount, are proposed to quantify the performance of CO chemical removal technology. Based on the physical characteristics of filtration-type and spraying-type CO removal processes, combined with the CO oxidation reaction mechanism on the surface of the removal material, the theoretical models describing the dynamic evolution of the mine CO chemical removal process are established, achieving the quantitative description of the CO chemical removal laws. The CO removal tests for the exhaust gas of trackless rubber-tired vehicles and high-temperature chambers are carried out. With 8.03 liters of removal material, the CO emission volume fraction during idle operation could be reduced to below 23×10⁻⁶. With a spraying amount of 100 grams of removal material, the CO volume fraction in the 200 ℃ chamber could be decreased from 2.5% to 0.09% within 60 seconds. The CO removal efficiencies all exceed 93%, confirming the effectiveness of the CO chemical removal method. Furthermore, the predicted evolution curves of CO volume fraction, CO removal efficiency, CO removal rate and total CO removal amount by the constructed theoretical model are in good agreement with the experimental results, with errors within 20%. Overall, the chemical removal method for CO in mines has a promising application prospect. This work provides a theoretical basis for the proactive mitigation of CO-induced disaster risks and the practical application of disaster emergency disposal.