Numerical analysis of multi-source PM generation and diffusion rate optimization during LHD muck handling in a polymetallic underground mine.

Particulate matter (PM) poses significant health and environmental pollution risks in underground mines, particularly during load-haul-dump (LHD) operations. However, previous studies have not fully explored the multiple sources of PM generation and diffusion associated with LHD loader mucking ore in a polymetallic underground mine. This study addresses the research gap by adopting both field experimentation and numerical simulation to assess PM propagation under three distinct LHD loader operating conditions: (Condition 1) loading at the working face, (Condition 2) dumping inside the temporary dumpsite, and (Condition 3) dumping onto an underground mine truck (UMT). Ansys-Fluent and regression analysis tools were used to accomplish the results. The findings revealed complex airflow patterns comprising backflow, vortex, unsteady, and steady flow regions. Condition 2 exposed the LHD operator to the highest PM concentration, followed by Condition 1, while Condition 3 resulted in higher PM exposure for the UMT operator compared to the LHD operator. Furthermore, the study analyzed the PM diffusion rate under four volumetric airflows and proposed the optimal volumetric airflow for mitigating miners' PM exposure. These findings have significant implications for optimizing mining operations schedules and the development of strategies to mitigate miners' exposure to elevated PM concentrations.