Soundless chemical demolition agents (SCDA) are recognized as a safe and sustainable alternative for rock breakage, with the potential to reduce reliance on explosives in mining. However, their mechanical performance is considerably hampered in the extreme cold climate, with slow or no rock fracturing observed. To overcome this deficiency, two methods were developed in recent studies by 1) electric heating the SCDA borehole with high-temperature wire, and 2) increasing the SCDA mixing water temperature. Good results were obtained with both methods. This paper explores the merits of a hybrid approach combining the two methods to further enhance the SCDA efficiency in the extreme cold environment. The new method, termed accelerated rock breakage (ARB), is tested in the temperature-controlled chamber at ambient temperatures of –20°C to –60°C using 203.2 mm (8-inch) cubic granite rock samples. The results demonstrate that the ARB method is superior to previous methods. For instance, at –40°C ambient temperature, increasing the mixing water temperature to 50°C while applying 25 V to the wire reduces the time to first crack (TFC) and minimum demolition time (MDT) to only 0.7 and 1.1 hours, respectively. The paper reports on the results of a detailed parametric study of 8 rock samples.
Darko et al. (Thu,) studied this question.