Diversified miner Rio Tinto has given the green light for the development of the fourth pipe, known as A21, at its Diavik diamond mine, in Canada’s Northwest Territories.
The A21 pipe development is part of the original mine plan and is estimated to cost $350-million over four years.
The 60:40 Diavik joint venture (JV) between Rio and Dominion Diamond Corp has approved the 2015 programme of works and A21 diamond production is planned for late 2018.
The A21 production would provide an important source of incremental supply for Diavik, ensuring the continuation of existing production levels, Rio said in a statement last week.
“Our decision to invest in the Diavik A21 project reflects our strong confidence in the diamond sector and in our ability to compete effectively in the industry,” said Rio’s diamonds and minerals CEO, Alan Davies.
The Diavik mine, located 300 km north-east of Yellowknife, began production in 2003 and became a fully underground mining operation in 2012. The mine produces predominantly gem-quality diamonds destined for high-end jewellery in all major consumer markets around the world.
The A21 kimberlite pipe is located just south of Diavik’s existing mining operations, and the development of the pipe would require rockfill dike construction to encircle the orebody located just offshore of existing mining operations at Lac de Gras.
Diavik will use the same innovative design and engineering technologies used to construct the Diavik mine’s two other dikes that enabled mining of three existing pipes.
A21’s measured resources are 3.6-million tonnes of ore at a grade of 2.8 ct/t, yielding about 10-million carats. In three sample programmes, 9 635 ct of rough diamonds were recovered at A21.