Mining Hitory: the Tau Tona Mine

The Tau Tona Gold mine in South Africa was extended to a depth of 3.9km in 2008, making it the world’s deepest mine at that time. The name TauTona means ‘great lion’ in Setswana (“TauTona Gold Mine, Anglo Gold, South Africa,” n.d.).

The mine was located at on the West Wits line, south of Carletonville, in South Africa’s North West province, about 70 km south-west of Johannesburg. TauTona, which includes Savuka, is a mature deep-level underground gold mine with a limited life-of-mine. Mining is undertaken predominantly on the Carbon Leader reef (CLR) horizon, with TauTona mining towards the boundary of Sibanye Gold’s Driefontein gold mine (Barradas, n.d.).

Geology/Mineralisation (Barradas, n.d.)

The CLR is the principal economic horizon at TauTona and the VCR is the secondary economic horizon. The CLR is located near the base of the Johannesburg subgroup, which forms part of the Central Rand group. The Central Rand group sediments are unconformably overlain by the Klipriviersberg lavas and the VCR is developed at the interface between the Central Rand group sediment and the overlying lavas. The CLR and the VCR at TauTona are vertically separated by about 900 m of shales and quartzites.

The CLR is a thin, on average 20-cm-thick, tabular, auriferous quartz pebble conglomerate and comprises three sedimentary facies or units. Economically, the most important is Unit 1, which is present as a sheet-like deposit over the whole mine, although reef development and grades tend to decrease rapidly where Unit 1 overlies Unit 2.

Unit 2 is a complex channel deposit that is present only along the eastern-most limit of current mining at TauTona. The Unit 2 CLR may be more than 2 m thick.

Unit 3 is preserved below Unit 1 in the southern parts of TauTona and is the oldest of the CLR conglomerates.

All production on the VCR at TauTona ceased in 2013 and no future mining has been planned on this reef horizon.

The CLR and VCR are cross-cut and displaced by faults and intrusive dykes and sills of various ages. The faulting, in conjunction with the many intrusives that displace and intersect these reefs, is responsible for most of the risk inherent in deep-level gold mining, since seismicity is associated with these geological features.

Reserves: Proven and probable reserves as at December 31, 2015, were estimated at 4.14-million tonnes, grading 7.91 g/t of gold.

Resources: Exclusive mineral resources as at December 31, 2015, were estimated at 2.77-million tonnes, grading 22.84 g/t of gold.

Mine Production

Production at TauTona fell to 409,000oz in 2007, down from 474,000oz in 2006, due to increased seismic activity. This required a review of the practice of mining of shaft pillars and high-grade remnant and delays to the build-up in volume caused by opening up of the sequential grid. Capital expenditure in Siguiri was R2.5bn ($71m) in 2007, with 56% committed to the development of ore reserve. TauTona accounted for 7% of AngloGold Ashanti’s total 2007 gold production (“TauTona Gold Mine, Anglo Gold, South Africa,” n.d.).

AngloGold Ashanti, the owner reported that “As at 31 December 2009, AngloGold Ashanti’s Ore Reserve totalled 71.4Moz and it employed 63,364 people, including contractors. Gold production for the year totalled 4.60Moz (2008: 4.98Moz), generating $3.8bn in sales revenue. Capital expenditure in 2009 was $1bn.”

The TauTona mine was put under orderly closure in 2017 and ore reserve was transferred to Mponeng mine, the infrastructure of which will access the carbon leader reef (CLR) orebody from 109 to 120 levels of TauTona’s current network as of 2020 (“TauTona Gold Mine, Anglo Gold, South Africa,” n.d.).

Reference

Barradas, S. (n.d.). Tau Tona mine, South Africa. Mining Weekly. Retrieved January 21, 2025,

from https://www.miningweekly.com/article/tau-tona-mine-south-africa-2016-08-05

TauTona Gold Mine, Anglo Gold, South Africa. (n.d.). Mining Technology. Retrieved January 21,

2025, from https://www.mining-technology.com/projects/tautona_goldmine/

Original Source: https://bit.ly/3PKoBYS