Name of the Project
Cullinan C-Cut Phase 1 expansion programme.

Location
Gauteng, South Africa.

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

Project Description
The Cullinan mine contains a world-class resource base of 194.2-million carats, as of June 30, 2016. Petra plans to capitalise on this by undertaking an expansion programme to increase production to an estimated 2.2-million carats a year by the 2019 financial year, comprising two-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 progress 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 to 38 to 40 carats per hundred tonnes (cpht) in the 2017 financial year to about 49 to 51 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.

Phase 2, which is still at the conceptual phase and not included in the LoM to 2030, aims to further expand Cullinan’s RoM production to four-million tons a year, with a yield of two-million carats a year from 2019 to 2030. The conceptual framework indicates that Phase 2 will expand the C-Cut by another 7.8 ha.

Jobs to be Created
A crew of 45 Murray & Roberts Cementation personnel is working on the project site; however, during the peak development phase of the programme, from May 2014 to May 2015, 386 employees were on site.

Net Present Value/Internal Rate of Return
Not stated.

Value
R4-billion.

Duration
The plan is to increase production from 729 496 ct to 2.2-million carats by the 2019 financial year.

Latest Developments
Cullinan production increased 20% to 227 523 ct in the third quarter ended March 31, 2017, mainly owing to an increase in RoM  carat production as the new C-Cut Phase 1 mining area continued to ramp up as planned, with resultant improved RoM grades increasing by 26% to 38.4 cpht.

RoM production from the C-Cut is expected to reach about one-million tonnes for the full 2017 financial year.

Key Contracts and Suppliers
MDM Engineering, the South African division of Amec Foster Wheeler (Cullinan plant contract) and Murray & Roberts (Cullinan shaft contract).

On Budget and on Time?
The project is progressing well and in line with expectations.

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