Experimental assessment of peak carbon monoxide mitigation after rock blasting using a Co3O4-based agent: Effects of charge system and lithology

Le résumé fourni par la source

Post-blasting carbon monoxide (CO) can rapidly accumulate in underground metal mines and pose acute poisoning risks to workers. In this study, a small-scale rock blasting simulation system was developed based on an iron mine in Anhui Province, China, to preliminarily evaluate source-level peak CO mitigation using a Co 3 O 4 -based eliminator. Granite, diabase, and marble specimens were blasted using an emulsion explosive system and a porous prilled ammonium nitrate-fuel oil (ANFO) assisted initiation system. Baseline CO generation tests and in situ mitigation tests were conducted to examine the effects of eliminator dosage, charge system, and lithology on peak CO reduction efficiency measured at a fixed exhaust-valve sampling point. Under granite conditions, increasing the eliminator dosage generally reduced the measured peak CO concentration, and the best-performing tested dosage occurred at an eliminator-to-explosive mass ratio of approximately 4:5. Further increasing the dosage produced no additional improvement, suggesting an apparent plateau within the tested range rather than a statistically confirmed optimum. At this dosage, the peak CO reduction efficiency was 80.0% for the emulsion explosive system and 72.2% for the porous ANFO assisted initiation system under granite conditions. Under diabase and marble conditions, the corresponding efficiencies were 83.6% and 83.2% for the emulsion explosive system, and 79.6% and 79.6% for the porous ANFO assisted initiation system. Numerical simulations qualitatively suggested that the more developed fracture network in granite may form more complex gas-release pathways, providing a plausible explanation for the lower apparent reduction efficiency observed in granite. Because each experimental condition was tested once and CO was measured at a single sampling point, the results should be interpreted as preliminary trends under controlled small-scale conditions rather than statistically validated or field-scale conclusions. These findings provide initial experimental evidence for source-level peak CO mitigation in metal mine rock blasting and indicate the need for replicated tests, spatial gas monitoring, CO 2 verification, and field-scale validation.

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