Exposure-reduction projects that include innovation and the use of new technologies are part of our commitment to reducing potential occupational exposures at our assets.
In South Australia, the team at our Olympic Dam underground copper mine initiated a project in FY2016 to modify its diesel equipment fleet to actively control exposure to DPM.
As one of the largest underground copper mines in the world, Olympic Dam has around 800 miners and uses diesel equipment for development, production, ore handling and mine services.
Using best-in-industry science to direct the project, the team implemented a vehicle replacement strategy that incorporates low-emitting engine technologies. As a total fleet replacement cannot happen immediately, an interim solution to install diesel particulate filters on haul trucks, underground loaders and drill rigs has been implemented. As a result of this work and the continual focus on exposure reduction, Olympic Dam has lowered the average DPM exposures across the underground mine by 80 per cent since 2006.
In addition to these measures, potential expansion projects at Olympic Dam are now evaluated for their impact to existing diesel exhaust exposures. By justifying non-diesel intensive strategies, we are reducing our future reliance on diesel technologies.
In Chile, our Escondida open-cut copper mine implemented control measures to reduce potential exposure to respirable crystalline silica during the mine blasting process. The most effective control measure is dust abatement using atomisers fed from water tanks installed on earth-moving machinery. The atomisers operate as the blasting agents are unloaded into the boreholes in the blasting platforms, spraying a water mist directly over the source of the silica-containing dust. This decreases the dust, reducing potential exposure to silica by between 51 and 66 per cent and significantly improving the work environment for operators.
This project follows others developed in previous years, such as the ‘Golden West’ additive in Escondida’s crushers, a polymer that keeps the mined material damp from the crushers through to the stock pile, reducing dust emissions in these areas.
Following the effectiveness of the project in reducing potential silica exposure, water abatement of dust is now a technical specification for machinery used for blasting at Escondida and the approach is being shared across BHP.