Name and Location
Cullinan C-Cut expansion programme, Gauteng, South Africa.

Client
Petra Diamonds (74%), Thembinkosi Mining Investments (14%) and the Petra Diamonds Employee Share Trust (12%).

Project Description
The Cullinan mine contains a world-class resource base of 200.8-million carats, including 17-million carats in tailings. Petra plans to capitalise on this by undertaking an expansion programme to increase production to 2.2-million carats a year by the 2019 financial year.

This expansion plan, known as C-Cut Phase 1, will establish a new block cave on the western side of the orebody, in the upper portion of the major C-Cut resource, which is estimated to contain 133-million carats and will also involve a large tailings operation.

The development plan will enable the tonnage profile to gradually switch from diluted to undiluted ore. As a result run-of-mine (RoM) grade is expected to increase in future years to about 35 carats per hundred tonnes (cpht) by the 2015 financial year, 37 cpht by the 2016 financial year and to more than 50 cpht by the 2019 financial year, when the C-Cut Phase block cave is in full production.

Petra’s current mine plan has a life of 17 years, but the major residual resources at the mine indicate that the actual life-of-mine could be more than 50 years.

Value
Not stated.

Duration
The plan is to increase production from one-million carats in 2011 to 2.2-million carats by the 2019 financial year.

Latest Developments
Petra reported in its interim results that RoM grade at Cullinan will remain a challenge while production continues to come from the mature areas of the mine, as a result of the significant dilution of the ore drawn in these older production zones.

However, from the 2016 financial year the grade is expected to start to increase gradually, eventually rising to about 50 cpht by the 2019 financial year, once only undiluted ore is being mined and treated.

The development of the underground declines and access tunnels, as well as the shaft preparation work, is progressing in line with expectations. The South decline has now been completed and development of tunnels has progressed apace, with 7 068 m out of a total of 24 575 m developed to date.

Key Contracts and Suppliers
Murray & Roberts Cementation (deepening of Shaft 1 and Shaft 3, as well as associated infrastructure and planned level development) and ABB (upgrade of the Koepe winder and ropes).

On Budget and on Time?
Not stated.

Contact Details for Project Information
Petra Diamonds, tel +27 11 702 6900, fax +27 11 706 3071 or email info@petradiamonds.com.
Murray & Roberts Cementation, tel +27 11 201 5000.
ABB (South Africa), tel +27 10 202 5000 or fax +27 11 579 8000.