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

Location
Gauteng, South Africa.

Project Owner/s
Petra Diamonds (74%), Kago Diamonds (14%) and the Itumeleng Petra Diamonds Employee Share Trust (12%).

Project Description
The Cullinan diamond mine is renowned as a source of large, high-quality gem diamonds, including Type II stones, and is the world’s most important source of very rare blue diamonds.

The C-Cut Phase 1 project plans to capitalise on the mine’s resource base. The C-Cut Phase 1 block cave  consists of eight tunnels and 107 draw bells, with 187 individual draw points.

Production from the C-Cut cave has been largely concentrated in the south-western area, which covers about 25% of the C-Cut footprint and has produced 75% of the ore to date.

The project’s development is focused on Cullinan’s C-Cut Phase 1 block cave and the CC1 East development – a new sublevel cave on the eastern side of the mine – of the North Crusher 2, and rehabilitation in the North West Corner of C-Cut Phase 1.

Cullinan’s indicated resource of 229-million tonnes, containing 135-million carats, could allow for a considerable extension to the mine life.

Capital Expenditure
Not stated.

Planned Start/End Date
Steady-state production from C-Cut Phase 1 and CC1 East was achieved in the 2020 financial year.

Latest Developments
During September 2021, the southern part of T41, the most eastern tunnel of Cullinan, was subjected to a sudden and rapid onset of convergence, which required immediate intervention. This resulted in the installation of additional support to protect the tunnel for the longer term, and the closure of the southern access to T41. This, together with the previously reported closure of the northern access to the tunnel, has resulted in the 18 draw points in T41 not being accessible for the remainder of 2022 financial year.

An investigation to determine the root cause of this convergence is in progress, together with the development of a plan to mitigate its impact on the mine’s production.

While opportunities to mitigate the impact of the afore-mentioned measures are being investigated, early indications are that without any mitigation, the convergence could result in a reduction of about 75 000 ct to 100 000 ct in the mine’s 2022 financial year production.

Cullinan’s production is now expected to be at the lower end of the company’s earlier guidance of 1.7-million carats to 1.9-million carats, if no mitigating steps are taken.

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

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