Influence of the Nano-Iron Oxide Adsorption-Enhanced Microstructured Charcoal Additives on the ANFO’s Properties

Abstract

The article presents the results of the third research stage on the potential microstructured charcoal additives in ANFO. The charcoal powder was liquid adsorption-treated with Fe in various ratios. Adding MC-Fe to ANFO changed the exothermic peak’s position from ca. 280 °C to 250 °C due to lower activation energy, which influenced the kinetics of the reaction. Bruceton’s test indicated that the MC-Fe addition to ANFO resulted in ca. 10% lower initiation energy in comparison with pure ANFO. However, the energy level did not influence the potential applicability of the additives. The fumes analysis indicated a lower concentration of CO for all tested samples; however, the concentration of NOx rose. The thermodynamic calculations confirmed the experimental results, which could be explained by the increased positive oxygen balance. Moreover, all analyses showed that the most promising blasting properties referred to the ANFO sample containing the microstructured charcoal additive of a C:Fe ratio of 4:1. Therefore, further research will be dedicated to advanced studies between the chemical composition of this specific ANFO sample and its physicochemical and blasting properties.