South Africa

Cullinan Mine

Click for more information

Categories

Overview

Mine TypeUnderground
Commodities
  • Diamond
Mining Method
  • Block caving
  • Sub-level caving
Production Start... Lock
Mine Life... Lock
ShapshotCullinan Mine is the world’s most important source of very rare blue diamonds (produce 80% of the world’s blue diamonds).

The C-Cut extension project was also approved by the Board in FY 2023 and is expected to have an IRR in excess of 35% with capital investment estimated at US$ 32 million over the live of the project. Capital expenditure commenced during the Year and is expected to see production commence in FY 2025.

Owners

SourceSource
CompanyInterestOwnership
Petra Diamonds Ltd. 78.4 % Indirect
Ownership Tree
Petra Diamonds Ltd.: 74%

Kago Diamonds (Pty) Ltd: 14%

Itumeleng Petra Diamonds Employee Trust (IPDET): 12%.

The IPDET holds a 12% interest in each of the Group’s South African operations, with Petra’s commercial BEE Partners holding the remaining 14% interest through their respective shareholdings in Kago Diamonds, in which Petra has a 31.46% interest. The effective interest percentages of Petra Diamonds attributable to Cullinan is 78.4%.

Contractors

Lock

- subscription is required.

Deposit type

  • Kimberlite

Summary:

The pipe intruded rocks of the Transvaal Supergroup as well as igneous rocks of the Bushveld Igneous Complex. The kimberlite has been radiometrically dated at 1179 ± 36 Ma using Rb–Sr in clinopyroxene and 1202 ± 72 Ma using U–Pb in perovskite. The pipe is itself intruded by a gabbro sill of 1150 Ma.

The internal geology of the pipe was first described by Wagner who noted the presence of a “floating reef” of Waterberg quartzite which occurred in the middle of the pipe and was associated with a considerable rubble zone of rounded quartzite and sandstone boulders. These Waterberg quartzite inclusions indicated the presence of this formation at the time of emplacement, but which has since been eroded from the area. Later geological work identified the presence of a number of discrete kimberlite varieties that included two major types of TKB, named the “Brown” and “Grey” kimberlites. The large floating reef referred to above occurred within the Grey Kimberlite along the boundary with the Brown. In addition, a central complex that consisted of several phases of kimberlite occurred within the Grey. This was referred to as the Black Kimberlite, which has an associated variety called the Piebald Kimberlite. The last phase of magmatism was the intrusion of carbonate-rich dykes.

Reserves

Lock

- subscription is required.

Mining Methods

Lock

- subscription is required.

Comminution

Crushers and Mills

Lock

- subscription is required.

Processing

Lock

- subscription is required.

Production

The Company is not able to precisely measure the ROM/tailings grade split because ore from both sources is processed through the same plant; the Company therefore back-calculates the grade with reference to resource grades.
CommodityUnits202320222021202020192018201720162015
Diamond carats  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe1,655,9291,368,720786,509680,813729,496
All production numbers are expressed as mineral.

Operational metrics

Metrics202320222021202020192018201720162015
Tonnes processed  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe5,075,441 t4,153,835 t2,389,087 t3,189,181 t4,971,310 t
Annual processing capacity  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe6 Mt6 Mt

Production Costs

Commodity production costs have not been reported.

Operating Costs

Currency20232022202120202019201820172016
Total operating costs ($/t milled) ZAR 332  312  260  270  234  239  316  257  

Financials

Units2023202220212020201920182017
Capital expenditures M USD  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe 46.3   73.9   151.2  
Sustaining costs M USD  ....  Subscribe  ....  Subscribe 6.8   6.5   4.3  
Revenue M USD  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe 171.4   167   91.3  
Operating Income M USD  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe -53.7   14   4.8  

Heavy Mobile Equipment

Lock

- subscription is required.

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Nov 13, 2023
....................... Subscription required ....................... Subscription required Subscription required Nov 12, 2023
....................... Subscription required ....................... Subscription required Subscription required Nov 12, 2023
....................... Subscription required ....................... Subscription required Subscription required Nov 12, 2023

EmployeesContractorsTotal WorkforceYear
...... Subscription required ...... Subscription required ...... Subscription required 2023
...... Subscription required ...... Subscription required ...... Subscription required 2022
...... Subscription required ...... Subscription required ...... Subscription required 2021
...... Subscription required ...... Subscription required ...... Subscription required 2020
...... Subscription required ...... Subscription required ...... Subscription required 2019
...... Subscription required ...... Subscription required ...... Subscription required 2018
...... Subscription required ...... Subscription required ...... Subscription required 2017
...... Subscription required ...... Subscription required ...... Subscription required 2016

Aerial view:

Lock

- subscription is required.