Articles techniques et présentations

Rock fragmentation is a main process in mining, quarrying, and civil engineering projects. Efficient and controlled rock fragmentation plays an important role in optimizing processes such as drilling, blasting, and comminution. However, these traditional methods often face challenges related to energy consumption, safety, and environmental impact. In recent years, high-voltage pulse fragmentation (HVPF) has emerged as a promising alternative to rock fragmentation. This technique utilizes high-voltage electrical pulses to induce rapid and selective disintegration of rocks. Furthermore, the use of multiphysics modeling and simulation in the development of processes is increasing due to their ability to couple models governed by different physical laws, a task that would otherwise be highly challenging. This approach enables a deeper understanding of the involved phenomena, enabling the prediction and enhancement of the performances of the investigated processes. HVPF uses a high pulse voltage to initiate electrical breakdown inside a dielectric material immersed in water, generating its disintegration. In HVPF, a discharge channel is formed inside the rock after applying a high-voltage pulse resulting in a high-initial current flow. Consequently, the rock, a non-conducting material, appears to be locally transformed into a conducting material, and the electrical energy is transformed into heat and mechanical energy. The high-voltage rock destruction may be considered a dynamic multi-physical problem consisting of three main physical problems: electric, thermal, and mechanical problems. In this study, we present a focused investigation of the electrical problem within the framework of COMSOL Multiphysics®, aiming to gain deeper insights into the underlying mechanisms of electrical fragmentation. This poster presents only the transient electrical problem governed by the conservation of charges equation using the AC/DC Module in the COMSOL Multiphysics® software. The entity, a few-centimeter cylindrical rock, is located between a high-voltage and a grounded electrode. The high-voltage electrode is given by a time-dependent voltage boundary condition. Subsequently, the developed numerical model is simulated under different input voltages. The electric properties distributions in a homogeneous dielectric material are obtained and analyzed.

Key Words: electrical fragmentation, rock breakage, electrical modeling, high-voltage pulses, COMSOL Multiphysics®