This paper aims at analyzing the concentration and size distribution of airborne dust as well as the re-entrainment possibility of settled dust in order to suggest efficient engineering measures for improving the work place environment at limestone mines with large cross-section. Concentrations of diesel smoke are also estimated by visual observation and size distribution. The airborne dust concentration during drilling and loading operations are within the permissible limit by Mine Health and Safety Act, while the estimated diesel smoke level is in the range of 0.380 and 1.620 mg/m3 and considerably exceeds the US MSHA TLV of 0.160 mg/m3. Within the 200 m downstream of drilling and loading operations, differences of the size distribution of settled dust on the wall and bottom are not significant. However, settled dust generated by blasting shows relatively finer size and has higher possibility of re-entrainment.
This paper aims at analyzing the concentration and size distribution of airborne dust as well as the re-entrainment possibility of settled dust in order to suggest efficient engineering measures for improving the work place environment at limestone mines with large cross-section. Concentrations of diesel smoke are also estimated by visual observation and size distribution. The airborne dust concentration during drilling and loading operations are within the permissible limit by Mine Health and Safety Act, while the estimated diesel smoke level is in the range of 0.380 and 1.620 mg/m3 and considerably exceeds the US MSHA TLV of 0.160 mg/m3. Within the 200 m downstream of drilling and loading operations, differences of the size distribution of settled dust on the wall and bottom are not significant. However, settled dust generated by blasting shows relatively finer size and has higher possibility of re-entrainment.
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