Name and Location
Cullinan C-Cut Phase 1 expansion programme, Gauteng, South Africa.

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

Project Description
The Cullinan mine contains a world-class resource base of 195.4-million carats, including 17-million carats in tailings. Petra plans to capitalise on this by undertaking an expansion programme to increase production to an estimated 2.4-million carats a year by the 2019 financial year, comprising 2.2-million carats run-of-mine (RoM) and 200 000 ct of tailings.

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. It will also involve a large tailings retreatment operation.

The development plan will allow for the tonnage profile to gradually switch from the old mining areas, heavily diluted with waste rock, to the new mining areas, thereby providing access to undiluted ore. As a result, the RoM grade is expected to increase in future years from about 26 carats per hundred tonnes (cpht) at the end of the first half of the 2016 financial year to about 55 cpht by the 2019 financial year, when the C-Cut Phase 1 block cave is in full production.

Petra’s current mine plan envisions a life-of-mine (LoM) to 2030, but the major residual resources at the mine indicate that the actual LoM could be more than 50 years.

Net Present Value/Internal Rate of Return
Not stated.

Value
Not stated.

Duration
The plan is to increase production from 700 000 ct in the 2015 financial year to 2.4-million carats by the 2019 financial year.

Latest Developments
The underground development at Cullinan continued to progress in line with expectations in the six months ended December 31, 2015, with the C-Cut Phase 1 waste development yielding a total of 971 mm, raiseboring delivering 387 m and kimberlite development delivering 1 354 m.

The shaft deepening is on track to be completed and commissioned during first half of the 2017 financial year.

Key Contracts and Suppliers
None stated.

On Budget and on Time?
The project is on time and within budget.

Contact Details for Project Information
Petra Diamonds, email info@petradiamonds.com.