Diavik completes the underground mine Phase 1

Moving the commercial production of A21 Underground mine 

Rio Tinto’s Diavik Diamond Mine has safely completed the development and construction of Phase 1 of the A21 underground mine, now moving the underground mine into commercial production.

Building on the success of the first phase, Phase 2 of the A21 underground project was approved earlier this year with an additional investment of US$17 million. The project will enable Diavik to maximise the value from its known resources through to closure.  

The construction of the A21 underground mine involved the development of over 1,800 metres of underground tunnels to access the orebody and begin underground production. With safety as the core focus, there were no lost time injuries after more than 100,000 labour hours completed over 20 months during the development and construction work.  

Chief Operating Officer of Diavik Diamond Mine Matt Breen said: “The A21 underground operation is positive news for our employees, partners, suppliers and local communities in the Northwest Territories, as it will enable operations to continue through to closure. Rio Tinto’s decision to proceed with Phase 2 is a testament to the excellent performance of our Diavik team in successfully developing the underground mine beneath the previously mined A21 open pit.”  

Rio Tinto is also continuing its investment in preparing for the closure and remediation of Diavik mine site, focusing on progressive reclamation activities such as earthworks, site clean-up, equipment procurement, and other closure readiness efforts.