During a professional dialogue today I was surprised to learn that Papua New Guinea still doesn’t have a legislative framework to regulate the management of waste rocks that are dug out and dumped around the mining’s and associated works in PNG.
The Government just gives them a mining permit and expects them manage their waste rocks in a ‘reasonable’ way so as not to impose adverse impact on the environment and its inhabitants including the people. Unfortunately the law does not define ‘reasonable’ here.
If the mining’s fail to manage this aspect well the long term consequences will be very very adverse and regrettable. The current bunch of greedy politicians and bureaucrats are only interested in collecting tax and royalties at the expense of the fate of the future generations on areas that will be affected which is totally unwise and absurd.
Each mining company under its Corporate Social Responsibility (CSR) charters have a duty of care to manage this aspect very well but the absence of this very legislation (or adoption thereof) confers them immunity if they choose otherwise to take heed in their operation and closure plans.
Below is a bulleted points of main ideas associated with waste rock management in any given mining sector:
Why manage waste rock?
· Prevent adverse environmental impacts
· Minimise closure costs
· Meet legal requirements
· Meet our corporate social responsibility and maintain social licence to operate
Waste Rock Management
· Waste rock is material that is mined from the Open Pit and Underground that does not bear gold, but must be removed to access ore grade material.
Competent rocks – hard rocks
- Competent rocks are place at the stable rock dumps
Incompetent rocks – soft rocks, top soil and mudstone
- Incompetent rocks are placed at erodible dumps
How are waste rock managed?
- Waste rock dumps must be correctly engineered and maintained to prevent failures
- Waste rock must be selectively placed to prevent acid mine drainage (see picture above)
Waste Rock Dump (WRD) Rehabilitation
- Completed waste rock dumps are rehabilitated by
– Covering the WRD with soil
– Applying fertilizer to assist plant growth
– Planting legumes and grass for ground cover
– Planting seedlings of local tree species
Testing and monitoring of the process is an integral part of this management process!
Balcony Perspectives 