De Beers proactively sought to reduce nitrate generation under their Building Forever – Protecting the Natural World Initiative at the Gahcho Kué site, Canada.
Located in northern Canada's sub-Arctic region, the Gahcho Kué diamond mine is a joint venture between De Beers Canada Inc. (51 per cent) and Mountain Province Diamonds Inc. (49 per cent). As the operator, De Beers is committed to high safety and sustainability standards, with a deep respect for the land and its surrounding pristine water bodies.
Since the mine's inception, Orica and De Beers have worked together to mitigate the environmental impact of blasting. The environmental monitoring team at Gahcho Kué noted increasing nitrate levels in mine water, a known issue with bulk mining explosives. Although nitrate and ammonium levels were within regulatory limits, De Beers proactively sought to reduce nitrate generation.
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Year-to-year results show a 78.85 per cent decrease in nitrate levels in 2023 compared to 2017. Orica were engaged in 2020 to complete full review of drill and blast process.
In 2020, De Beers engaged Orica to review the drill and blast process to align with industry best practices and improve safety and efficiency. Orica applied the Nitrate Risk Reduction (NRR) framework, a three-tiered approach to systematically reduce nitrate contributions from blasting in water. The Nitrate Risk Reduction (NRR) process identifies nitrate sources from blasting and implements managed changes to reduce them.
These changes include minimising bulk explosive waste, maximising detonation reliability and efficiency, and selecting products suited to the mine’s groundwater conditions and sleep time requirements. The site team reinforced best practices on-bench as part of the NRR strategy, introducing i-kon™ III electronic detonators to reduce misfires.
After establishing best practices on the bench and in blast design, the site launched a pilot program in early 2022 to evaluate Fortis™ Protect. This bulk system, featuring a specially formulated emulsion blend and a modified delivery system on an Orica Mobile Manufacturing Unit (MMU™), further reduces nitrates after best practices are implemented.
Orica’s Technical Service Lead, Steve Jackson said:
Partnering with our valued client De Beers since the start of mining operations at Gahcho Kué has shown the true power of teamwork. Their insights, dedication, and trust have ensured the success of the nitrate emission reduction project. This partnership has inspired us to develop a commercial offering that meets the stringent demands for sustainable mining practices. It is a privilege to work with such an exceptional team, whose commitment to excellence drives us towards a more sustainable and forward-thinking future in the mining industry.
Upon completing the pilot program and a rigorous eight-month evaluation, the site transitioned to using Fortis™ Protect 70 as the primary bulk explosive at the end of 2022. The environmental team at Gahcho Kué regularly monitors nitrate concentrations in mine water. Year-to-year results show a 79 per cent decrease in nitrate levels in 2023 compared to 2017. Switching to Fortis™ Protect has significantly reduced nitrate loading in surrounding water bodies that drain into Great Slave Lake. A full year of data has been collected, and a multi-year monitoring program is underway to verify the long-term effects of using Fortis™ Protect compared to the previous explosive on site.
Orica’s Manager of Marketing, Surface Explosives, Yosep Irsana said:
Orica's Nitrate Risk Reduction framework is not just about tackling nitrate leaching; it is about forging a sustainable future for our customers. Rooted in innovation, Orica is dedicated to solving our customers' challenges. Our collaboration with key partners like Gahcho Kué highlights our commitment to effective frameworks. With confidence in our strategic pillars, we are delivering smart solutions and partnering for progress in action. Together, we cultivate a challenge, nurturing growth while safeguarding the environment.
The success at Gahcho Kué was presented by De Beers and Orica at the 2024 CIM CONNECT, Canada’s premier mining trade show. The full case study is
available for download at Orica.com.About Nitrate Risk Reduction
Orica’s Nitrate Risk Reduction is a collaborative approach to the management and reduction of nitrate on the mine site, from bulk plant to blasting operations.
The framework uses a simple, three step approach that includes engaging the site, an in-depth audit, and solution using a combination of products and services.
Nitrate risk reduction approach will thoroughly uncover the pathways for nitrate leaching into water systems from the ammonium nitrate based bulk explosives to blasting operations at mine sites, and create cost-effective solutions to reduce the risk across but not limited to the following:
- Explosives handling and management
- Mine water conditions
- Explosives usage
- Blasting operations
- Physical properties and chemistry of bulk products