Waste
We generate both mineral and non mineral waste during our mining and processing operations. Through effective management, we limit the negative environmental impact of our activities and reduce our operating costs and risks.
Our waste strategy allows us to improve our understanding of the true cost of dealing with waste. This in turn helps when planning for new projects and for closure, as these costs are often underestimated.
Our main focus is on the highest risk area: chemically reactive waste. This is a small percentage of our total mineral waste but potentially the most harmful.
By effectively managing our waste, we support improved environmental performance as well as our biodiversity and water programmes.
- Approach
- Engagement
- Results
Mineral waste
An estimated 1,464 million tonnes of mineral waste (predominantly waste rock and tailings) were disposed or stored in 2010. About 54 per cent of this mineral waste was used as in pit or underground backfill. This is an important use for our mineral waste as it ultimately allows open pits to be reclaimed and re-vegetated.
Eighteen per cent of the mineral waste that we disposed or stored in 2010 is considered to be geochemically reactive. Approximately 30 per cent of the land surface used for reactive mineral waste disposal has been covered or capped to preserve water quality and allow vegetation to be re-established.
All existing mines and advanced projects where ARD could pose a significant risk have been visited by the ARD risk review programme to assess each operation's ARD hazards and management strategies (23 operations since 2004). Six monthly reporting by these operations indicates that significant progress is being made to address the issues raised by the site visits. Given the long term strategic nature of many of the ARD issues identified, and the long lead times to design and implement some of the studies and corrective actions, we anticipate that this work will continue for many years. All managed operations where an ARD risk review or a mineral waste optimisation programmes have been completed were in compliance with the relevant government regulations and permit conditions.
Non mineral waste
We disposed or stored 372,430 tonnes of non mineral waste in 2010. Aluminium smelters contributed 34 per cent of this total.
Aluminium smelters generate specialist wastes produced through the smelting process, including spent cell lining, bath, carbon fines and refractory bricks, which continue to be accumulated on site. Our largest managed copper producer disposes of significant quantities of non mineral wastes to landfill and other disposal locations.
Our operations disposed or stored 149,380 tonnes of hazardous non mineral waste in 2010. 59 per cent of this total was from aluminium smelters (spent cell lining and kiln grade spar). At the end of 2010, 24 per cent of hazardous waste generated during the year was placed in storage pending final disposal or recycle/reuse.
We found off site opportunities for reuse or recycle 320,620 tonnes of our non mineral waste in 2010, including 126,480 tonnes of bulk processing materials from aluminium smelting and 105,720 tonnes of hazardous waste.
