Continual improvement to the mining sector’s environmental performance is a top priority for the industry, government and the communities where mining operations are located. Most recently in Canada, multiple stakeholders came together to advance sustainability in the sector.
On January 16, 2017, a workshop on Water Management in Mining and Mineral Processing was organized jointly by CanmetMINING, Natural Resources Canada and the Canadian Mining Innovation Council in Ottawa. The purpose of the workshop was to provide feedback on a draft research plan prepared by CanmetMINING which centered on achieving Minimal Liquid Discharge (MLD) from mining operations in Canada.
Workshop participants were invited from the mining industry, government, academia, EPCM companies and solution providers with specialized consulting expertise such as BQE Water. Participants were divided into four groups and asked to brainstorm about the challenges, priority areas and knowledge gaps separately. Remarkably, feedback from all groups revealed common themes.
Achieving MLD is not necessarily the right objective
- Operations with positive water balances require active discharge of excess water as part of an overall water management and risk mitigation plan (avoid a Mt Polley repeat)
- Concurrent minimization of discharge and enhanced water recycle may increase the inventory of contaminants and liabilities that need to be addressed at closure
Climate change affects mining through not only carbon footprint but also water management
- As a major consumer of energy, the industry’s bottom line will be affected by carbon pricing
- Changes in climate introduce new business risks related to water management that need to be mitigated to avoid disruptions caused by either water scarcity or extreme wet events
Selenium is a constituent of particular concern
- Selenium is omnipresent in mineral deposits
- New science based regulatory limits are being enforced in the US and Canada
Adopting dry stack tailings systems as the Best Available Technology to mitigate risks of tailings dam failures may not be prudent for the industry
- Dry stack systems may in some cases replace the risk of geotechnical stability of dams with the geochemical stability risk of tailings exposed to air and is subject to dusting
BQE Water proposed that the industry would benefit from a Guidance Document that would establish clear links between water management decisions and project risks and environmental liabilities. The document would not be a catalogue of technological solutions for particular water issues but introduce a methodology for assessing the risks and benefits of pursuing different water management strategies during the many stages of the mine life cycle.
CanmetMINING is expected to summarize the workshop findings and announce changes to their research plan later this year. Stay tuned for follow-up on this workshop!
David Kratochvil, PhD, PEng