Rio Tinto approves Diavik underground mining

Rio Tinto approves Diavik underground mining

Rio Tinto approves Diavik underground mining

Rio Tinto has approved investment in the underground mining phase of the Diavik Diamond
Mine. The approval is for additional funding of US$563 million bringing the total investment
to date in the underground mine to US$787 million. The investment will be funded by the two
Diavik joint venture partners, Rio Tinto at 60 per cent and Harry Winston Diamond
Corporation (formerly Aber Diamond Corporation) at 40 per cent.

Under the current life of mine plan, diamond production from underground would begin in
2009 and continue beyond 2020. Open pit mining is expected to cease in 2012, at which
time Diavik would become an all underground mine. Diavik’s total mine life remains within
the 16 to 22 years projected in the original feasibility study of 1999.

To support underground mining, Diavik must construct new surface works including a
crusher and paste backfill plant, expand its water treatment and power generating plants,
and construct ancillary facilities including fuel and cement storage, and additional
accommodation facilities. Approximately 20 kilometres of underground development works
will also be established to bring underground mining into production. The capital investment
of US$563 million will be spent over the next two years, adding to the US$224 million
invested in 2006-07 for the underground feasibility studies and related capital projects.

This significant new investment in underground mining will provide training, employment,
and business opportunities in addition to those significant benefits that Diavik already
provides. Diavik remains firmly committed to continuing its work with local communities and
governments to meet its socio-economic and its environmental commitments.

The Diavik Diamond Mine, located 300 km. northeast of Yellowknife, Northwest Territories,
is an unincorporated joint venture between DDMI (60 per cent) and Aber Diamond Mines
Ltd. (40 per cent). Both companies are headquartered in Yellowknife, Canada. DDMI is a
wholly owned subsidiary of Rio Tinto plc of London, England, and Aber Diamond Mines Ltd.
is wholly owned by Harry Winston Diamond Corporation of Toronto, Canada. DDMI is the
operator of the project.