Orica and De Beers collaborate to reduce nitrate concentrations

Located in northern Canada’s sub-Arctic region, the Gahcho Kué diamond mine is a joint venture between De Beers Canada Inc. (51%) and Mountain Province Diamonds Inc. (49%). 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.

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 programme 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 programme 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% 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 programme 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.”

Read the article online at: https://www.globalminingreview.com/mining/28062024/orica-and-de-beers-collaborate-to-reduce-nitrate-concentrations/