Respirable dust pollution characteristics within an underground heading face driven with continuous miner – A CFD modelling approach

Abstract

Respirable dust pollution at an underground heading face driven with continuous miner was detected during a ventilation survey. In order to obtain fundamental understandings of the airflow patterns and the respirable dust dispersion characteristics within the heading face, three dimensional Computational Fluid Dynamics (CFD) models were developed according to field condition. The continuous miner (JOY 12CM27), which significantly impacts the ventilation and respirable dust flow behaviour, was embedded into the model. The inappropriate ventilation arrangement, lack of effective dust control measures, as well as insufficient maintenance of equipment (e.g. blunt picks, missing nozzles etc.) were identified as the main reasons causing the high dust exposure levels (greater than 500 mg/m3). Based on the CFD model results, a new ventilation arrangement together with dust mitigation strategy were proposed. And an evaluation of the proposed system demonstrated a high respirable dust mitigation effect (90%) could be achieved. Therefore, it is highly recommended these control strategies to be implemented immediately to address the extremely high dust levels in the underground working environment. The proposed strategy will be also suitable for headings with similar conditions and could provide guidance for mining operators to refer.