Phase 2 of the A21 underground project was approved earlier this year with an additional investment of US$17 million.
Phase one below A21 is slated to produce an extra 1.4 million carats, with phase two adding another 800,000 carats.
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.
Rio said there were no lost time injuries after more than 100,000 labour hours completed over 20 months during the development and construction work.
“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,” Diavik mine chief operating officer of Matt Breen said in the statement.
“Rio Tinto’s decision to proceed with Phase 2 is a testament to the excellent performance of…


