09:05 〜 09:30
[2101-06-01] Microwave irradiation for rock precondition in mining excavation
司会：才ノ木 敦士（熊本大学）
キーワード：rock-microwave、rock preconditioning、mining excavation
Efficiently breaking hard rocks remains a persistent challenge in mining and geotechnical engineering. Traditional explosive-based methods such as blasting, while effective in some cases, bring about a host of issues including but not limited to continuous productivity rate, noise pollution, dust, vibration, mine collapse, and safety hazards. Consequently, the mining sector seeks to transition from non-continuous explosive-based techniques to continuous mining approaches. However, continuous mining methods suffer from drawbacks such as the short life span of the cutting blades, especially when dealing with hard rocks. Rock pre-conditioning has emerged as a promising solution to address the challenges and facilitate the shift towards continuous mining. Among the various pre-conditioning methods, microwave treatment has achieved significant attention over the past decade. This research endeavours to assess the efficacy of microwave treatment as a rock pre-conditioning method through a combination of experimental and numerical analyses for field applications and introduce potential ways for its improvement. A comprehensive series of experiments, including microwave treatment, calorimetric measurements, thermal imaging, and rock mechanical testing, are conducted using a novel energy efficiency-based approach. Additionally, a fully coupled numerical model is developed to simulate heat transfer and energy absorption behaviours in rocks during microwave treatment, validated against experiments conducted in this study. The developed numerical model is leveraged to enhance the energy efficiency of microwave treatment experiments. Through the integration of an energy efficiency-focused perspective, this research offers new insights into the potential application of microwave treatment for rock pre-conditioning in field settings. Moreover, the developed numerical model contributes to a deeper understanding of the mechanisms underlying microwave treatment and aids in achieving superior energy efficiency in experimental and potential field outcomes.