Respirable dust generation and mitigation in Australian underground coal mine development headings – applications of computational fluid dynamics for respirable dust modelling

Respirable coal and silica dust has long been recognised as causing lung diseases such as silicosis and Coal Worker’s Pneumoconiosis (CWP). These lung diseases and other lung diseases caused from mining are now placed under an umbrella term Mine Dust Lung Disease (MDLD). The re-emergence of MDLD (particularly CWP) in Australia has necessitated extensive research into the field of preventing MDLD. Computational Fluid Dynamics (CFD) has allowed the industry to model dust flow in underground coal mines, allowing for extensive testing in ventilation flow and other dust mitigation strategies to determine the best practice for individual coal mines. A literature review identified that further study into the applications and power of CFD in underground mining applications is necessary in the industry. Further study would allow the industry to apply the full power of CFD into modelling practices to test strategies and tailor dust mitigation practices for each individual mine to get the best possible results in dust mitigation. CFD modelling of an underground coal mine from NSW, using real development heading and equipment geometries, as well as real ventilation and dust monitoring data was conducted. Four modelling scenarios were conducted, with the continuous miner (CM) in roof cut and floor cut position, as well as with poor ventilation and good ventilation practices. The modelling identified that generally, the right-hand side of the CM (opposite side to the ventilation ducting) was at most risk to respirable dust exposure, with exposures well in exceedance of the legal limits during cutting and loading. The study identified the safest places on the CM for operators during cutting/loading, as well as identifying that a wait time of 30 seconds post-cutting and loading is required before operators move forward on the work platforms to commence bolting. The results of this study show that operators on the continuous miner are still at risk of respirable dust exposure in even the best of conditions, so further study into this field is necessary on this topic to aim to eliminate the risk of respirable dust exposure for operators in underground coal mines.