Rio Tinto plans expansion of Canadian diamond mine

Rio Tinto has approved the US$350m development of a fourth kimberlite pipe at its 60%-owned subarctic Canadian diamond mine, Diavik.

Development of the A21 pipe is expected to take four years, with diamond production expected for late 2018.

Production will provide an important source of incremental supply for Diavik, ensuring the continuation of existing production levels, the company said.

Rio Tinto diamonds and minerals chief executive, Alan Davies, said: "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."

Diavik is located under the Lac de Gras in the Northwest Territories of Canada, requiring a mixture of underground mines and rock dikes to hold back water for open pit mines.

The A21 pipe is located to the south of Diavik's existing mining operations and its development will require the construction of similar rockfill dikes to encircle the ore body located just offshore of existing mining operations at Lac de Gras.

Diavik will utilize the same innovative design and engineering technologies used to construct the Diavik mine's two other dikes that enabled mining of three existing pipes.