Methods to suppress dust on open pit drill rigs

Abstract

Spotters and samplers working around surface drill rigs can be exposed to high dust concentrations. In this study it was found that individuals were exposed to as much as 14.2 mg/m3, which exceeds the Occupational Exposure Level of 10 mg/m3. The work on which this paper is based included an extensive literature study, as well as field investigations on a surface mine in Namibia. A number of additional dust suppression interventions were identified. These improvements, listed below, will assist in reducing dust concentrations around the drill rigs: • Increase maintenance frequency on the shroud, sealing ring, suction pipes and filters of the drill rigs, • Design and install new overlapping rubber belts on the shroud of the DM45, • Install an air-blocking shelf on the inside perimeter of the shroud of the DM45, • Install an airflow meter to ensure that the QC: QB ratio never drops below 3:1, • Only allow wet drilling, • Flush the dust collector system more regularly with compressed air to ensure that it does not become blocked, • Introduce stricter supervision to ensure that the suction pipes are always connected to the shroud, • Give drill rig operators more advanced training to ensure more effective drilling in order to reduce dust levels. It can be concluded that the implementation of the recommended improvements in engineering controls, better maintenance practices and better operating practices will assist in preventing any potential respiratory diseases and the degradation of the surrounding environment.