Thermal Research on Toxicity of Smoke from Mine Cable Fires

In recent years, with continual improvement in the level of mining intelligence, the application of mining cables in mines has become increasingly widespread. However, the fires caused by mining cables are gradually increasing, posing a serious threat to miners’ safety. This paper selected two commonly used cable materials in mines, mine-used portable shielded rubber cable and mine-used cross-linked polyethylene insulated polyvinyl chloride sheathed power cable, and explored the smoke toxicity of the two cables using the NBS smoke density test box and Fourier transform infrared smoke density analyzer. Qualitative and quantitative analyses of the changes in combustion products were conducted, and the toxicity of combustion products was evaluated using smoke toxicity index and smoke toxicity evaluation model. The research results showed that both types of mining cables generated immense amounts of CO₂, CO, and HCl and trace amounts of SO₂ and NO₂ during the holistic combustion process. The toxicity index values of the two mining cables were 1.021 (mine-used portable shielded rubber cable) and 0.500 (mine-used cross-linked polyethylene insulated polyvinyl chloride sheathed power cable), respectively, showing opposite smoke toxicity performances before and after combustion. The toxicity index of HCl gas for the two mining cables was 12.04 times the reference concentration (mine-used portable shielded rubber cable) and 5.52 times (mine-used cross-linked polyethylene insulated polyvinyl chloride sheathed power cable), which was the main cause of casualties. In addition, attention should be paid to CO, HCN, CO₂, and NO_x as injurious gases. The research results of this paper provided a theoretical basis for the research on the toxicity of underground cable fire in coal mines and had important guiding significance for the early monitoring and warning of mine cable fire, underground personnel escape, and evacuation route planning.