Diavik Celebrates Production Start at A21
On August 20, 2018, Diavik held an opening celebration for the start of mining the A21 kimberlite. Invited guests included the company’s Indigenous community partners, representatives from the Government of the Northwest Territories and industry. This is the last of Diavik’s kimberlites to be mined, and it will not extend the mine’s planned closure in 2025 but will provide an incremental supply of ore. The A21 kimberlite was discovered in March 1993 and was the first major discovery by the Diavik team that included Aber Resources and Rio Tinto’s Kennecott Canada Inc., and also the first of Diavik’s four ore bodies to be discovered. In 2014, Rio Tinto approved US $350 million to bring A21 into production. Under Diavik’s mine plan, it is the fourth kimberlite pipe to be mined, preceded by the A154 South, the A154 North, and the A418 ore bodies. As with the other kimberlites, all if which were found underwater in Lac de Gras, a rockfill water retention structure, or dike, was built around the lip of A21 ore body to allow safe open-pit mining. After dike construction, water was pumped out, followed by pre-stripping of the overburden before mining could commence. The first diamonds were produced from A21 in March 2018. Diavik says A21’s reserves include 3.3 million tonnes of ore at 2.8 carats per tonne for a total of 9.4 million carats. (Source: Diavik 2018 sustainable development report).