Kloof is an intermediate to ultra-deep level gold mine, situated in the West Wits Line of the Witwatersrand Basin, near the towns of Randfontein and Westonaria, approximately 60km west of Johannesburg, in province of Gauteng, South Africa.
Statistics as at 31 December 2022
Life of mine
2032
Gold production
158,182oz
All-in sustaining cost
US$3,025/oz*
Workforce
10,444
employees and contractors
* Elevated costs due to the industrial action during the 2022 year and not reflective of a normalised year
Kloof was one of the three original assets acquired when Gold Fields International completed its unbundling transaction in February 2013. Mining operations have been carried out in the West Rand since the late 19th century and at Kloof in its current form since 2000 when several existing mining operations were amalgamated.
At 31 December 2022, Kloof had combined surface and underground gold Mineral Reserves of 3.4Moz and Mineral Resources of 25.9Moz.
A closer look
- In 1887, Gold Fields of South Africa Limited was established.
- In 1892, Gold Fields of South Africa Limited was renamed Consolidated Gold Fields of South Africa to mine the deep-level gold deposit of the Witwatersrand.
- Geophysical prospecting work conducted in the 1930’s led to the drilling and subsequent sinking of Venterspost Shaft in 1934, with first gold poured in 1939.
- In 1964, Kloof’s main twin-shaft complex was initiated and the mine was officially opened in 1968.
- In 2000, the formation of the Kloof Gold Mine in its present form commenced with the amalgamation of the Venterspost, Libanon, Kloof and Leeudoorn gold mines.
- In 2012, the conventional South African assets of Gold Fields Limited were unbundled into Sibanye Gold Limited.
- The No. 4 Shaft drop-down project feasibility study was completed in 2015, and in 2017, the project commenced, while the integration project for the optimisation of infrastructure was approved in 2018.
- Production returned to normalised levels following protracted industrial action, which saw limited production taking place between December 2018 and May 2019.
- The COVID-19 pandemic and the associated national lockdown halted all production from April to the middle of May 2020, at which point a gradual build-up in production was initiated.
- In 2021, the No. 4 Shaft depth extension project development was completed to 46 Level.
- Industrial action by all unions resulted in a production stoppage between March 2022 and June 2022.
The Kloof operation consists of four producing vertical shafts, namely No.1 Shaft, No. 4 Shaft, No. 7 Shaft and No. 8 Shaft. The reef horizon is accessed the deepest (46 Level is currently the deepest working level) at No. 4 Shaft, approximately 3,432m below surface. Underground development is extensive, as can be expected of a mature mine of this size.
Additional to the four producing shaft systems, one shaft is used for pumping, and one is on care-and-maintenance.
Fresh ore is processed at the No. 2 Plant, which is situated near No. 7 Shaft. In addition, selected Kloof surface rock dump (SRD) material is treated at the Ezulwini processing plant and also at the Driefontein No.1 Plant.
Underground infrastructure includes access infrastructure to convey personnel, materials and equipment to and from the working areas and associated services to support mining operations. Horizontal infrastructure includes crosscuts, return airway drives, footwall haulage levels and declines/inclines. Infrastructure required for ore flow and services include ore and waste passes, conveyor belts, battery powered rail conveyances, ore bins, loading stations, water dams, dewatering pump stations, secondary ventilation and workshops. Electrical, compressed air, and water reticulation are also part of the installed underground infrastructure.
The Kloof operation is operated under a converted mining right, held in terms of the provisions of the MPRDA under DMRE Ref No GP30/5/1/2/2(66) MR (Kloof MR), valid from 30 January 2007 to 29 January 2027, for gold ore and associated minerals, in respect of a mining area totalling 200.87km².
Based on the current LoM, Kloof will need to request an extension of the Kloof mining right through a renewal application in terms of the provisions of the MPRDA from 2027.
There are two active TSFs, namely Leeudoorn and Kloof No. 2.
The Leeudoorn TSF has a capacity of 36.4Mt and is fed by the Kloof No. 2 Plant. The LoM requirements for this TSF is 18.5Mt, resulting in a surplus capacity of 17.9Mt. The No. 2 TSF is fed from No. 1 Plant, which is in the process of being closed.
The Kloof Integration Project aims to optimise and rationalise the infrastructure between No. 3 Shaft and No. 4 Shaft, and between No. 1 Shaft and No. 3 Shaft. This has allowed for the phased closure of the No. 3 Shaft sub vertical shaft with the final closure of the main shaft-barrel planned for 2023. The final phase entails the re-opening of old development areas between No. 1 Shaft and No. 3 Shaft which will allow the mining of the remaining VCR and other secondary reefs at No. 3 Shaft, from No. 1 Shaft.
The Kloof Integration Project also involves the development of inclined access from 41 Level at No. 4 Shaft up to 40 Level at No. 7 Shaft. The development phase is complete and equipping is in progress. An extension of the same project entails a similar access to link 42 and 43 Levels together. This project will allow access via No. 7 Shaft resulting in more face time for crews. The access development for this extension is already underway.
The Kloof No. 4 Shaft Depth Extension Project consists of a decline ramping down one level below infrastructure. The decline between 45 and 46 Levels has been developed, and the remaining raiseboring and equipping is in progress. The access ramp was developed by means of mechanised mining equipment. A raisebore drillhole site has been established and will be drilled and reamed back up to 45 Level for infrastructure and return ventilation purposes. The first raisebore hole will be completed in 2023.
