Underground mining

The Argyle Diamond Mine is currently in the process of transitioning from an open pit to an underground mine, extending the life of the mine until at least 2020.

The construction of the block cave mine was approved by the Rio Tinto Board after extensive feasibility studies into the safest and most economic way to reach deep into Argyle's ore body. In this area Argyle is leading the way for the Australian mining industry; it will be the first block cave mine in Western Australia and one of only a handful in Australia.

Block cave mining involves undercutting the ore body and allowing it to break up or 'cave' under its own weight, removing the need for explosives or blasting.

At full production, the Argyle underground mine will generate around 9 million tonnes of ore per annum, and on average approximately 20 million carats per year over the life of the block cave.

A range of consultation and formal approval processes with Traditional Owners and Government was also required to enable commencement of an underground project at Argyle. In 2004 a Participation Agreement was formed with Traditional Owners which provides a solid foundation for relationships and specifies Traditional Owner endorsement of the underground operation. In April 2005 the National Native Title Tribunal registered the agreement on the Registrar of Indigenous Land Use Agreements, making it an official and binding document.

During 2011 and the first half of 2012 the construction has included finishing the underground workshop, roadway construction, installing the crushers, finishing the dewatering pumps and firing of the first production drawbells. The commissioning of the mining automation systems, pumping systems, production draw and operational teams will take place in 2013, with full production reached in 2014.

For more information on Argyle's underground mine, see the Argyle Diamonds Underground Mine Facts at a Glance.