Experimental Study and Application on the Matching of Temperature and Sensitizer Concentration for Bulk Emulsion Explosive Matrix

This study systematically investigated the synergistic relationship between matrix temperature and sodium nitrite concentration to resolve density unevenness and explosive power instability in site-mixed emulsion explosives caused by the mismatch between matrix temperature and sensitizer (sodium nitrite) concentration during production. Using an orthogonal experimental design, matrix temperature gradients ranging from 40℃ to 70℃ and sodium nitrite concentration gradients ranging from 1.2% to 2.8% were systematically established. Multiple sets of comparative tests were conducted to comprehensively examine the impact of these two factors on the density of emulsion explosives. The experimental results demonstrate that matrix temperature plays a critical role in determining the foaming reaction rate, with elevated temperatures markedly accelerating the reaction and, consequently, the foaming process. However, this acceleration often leads to excessive foaming, consequently reducing the explosive density. In contrast, lower temperatures slow the reaction, often resulting in insufficient foaming, which increases explosive density and adversely affects blasting stability. Additionally, the concentration of sodium nitrite, acting as the sensitizer, directly influences both the foaming efficiency and the structural stability of the bubbles. For different matrix temperatures, there is an optimal concentration range to achieve ideal explosive density and detonation performance. Based on comprehensive experimental data, this study developed practical guidelines for sodium nitrite proportions across various matrix temperature ranges. These guidelines explicitly recommended specific sensitizer concentrations for low-to high-temperature conditions, providing quantitative references for field applications. Field validation confirmed that implementing this matching table and associated control techniques substantially enhanced the accuracy of emulsified explosive density regulation. This improvement not only boosted the effective release of explosive energy but also mitigated safety risks, including density-related misfires, resulting in overall optimization of both blasting performance and operational safety. This study's findings offer valuable theoretical insights and practical applications for enhancing quality control in field-mixed explosives and systematically improving blasting performance.