Name of the Project
Diavik A21 underground project.

Location
Northwest Territories, Canada.

Project Owner/s
Rio Tinto.

Project Description
The project involves the underground mining below the existing A21 openpit at the Diavik diamond mine.

Phase 1 of underground mining at the A21 pipe is expected to deliver an additional 1.4-million carats of rough diamonds. More than 1 800 m of underground tunnels were developed to access the orebody and start underground production.

Phase 2 is expected to deliver an additional 800 000 ct of rough diamonds.

Commercial production at the Diavik mine is expected to end in 2026.

Potential Job Creation
Current employees and contractors will be transferred from other areas of the mine for the construction and production phases of the project.

Net Present Value/Internal Rate of Return
Not stated.

Capital Expenditure
Phase 1 required a $40-million investment, while  $17-million is estimated for Phase 2.

Planned Start/End Date
Phase 1 took 20 months to complete. 

Latest Developments
The development and construction of Phase 1 have been completed, with the mine now being advanced into commercial production.

Phase 2 was approved earlier this year. The project will allow for maximising the value of the known resources of the Diavik mine until its closure.

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

Earlier this year, Rio Tinto installed a 3.5 MW solar plant at Diavik, which is the largest off-grid solar plant across Canada’s territories. The plant will provide up to 25% of Diavik’s electricity during closure work, with commercial production at the mine expected to end in 2026 and closure to run until 2029.

The solar project complements the wind power plant that has been operating since 2012; it is the largest wind power installation in Canada’s North, having generated more than 195-million kilowatt-hours of electricity since activation.

Key Contracts, Suppliers and Consultants
None stated.

Contact Details for Project Information
Rio Tinto, email media.enquiries@riotinto.com.