A 1 200km² footprint
Ergo Mining (Pty) Limited (Ergo) has a vast footprint adjacent to Johannesburg on the central and eastern Witwatersrand of South Africa. Its assets cover an area approximately 62km from east to west and 25km from north to south. This large, single footprint has been created as part of a rationalisation process and in order to simplify the structure of DRDGOLD’s companies. A single retreatment business also has the effect of improving synergies and saving costs. The restructuring took effect at the beginning on 3 July 2012.
Ergo’s flagship metallurgical plant, some 50km east of Johannesburg in Brakpan, and the Knights plant in Germiston together comprise what is arguably the world’s largest gold surface tailings retreatment facility. Together with the milling and pump station at Crown Mines and City Deep (both former plants), the new consolidated Ergo operation processes 2.0 - 2.1 million tonnes of gold-bearing material a month.
The Ergo footprint[Zoom in]
History: DRDGOLD acquires Ergo
Ergo was re-established in 2007 as Ergo Mining (Pty) Limited – a joint venture between DRDGOLD and Mintails Limited. The primary aim was to recover and treat – over a period of 12 years – some 186 million tonnes (Mt) of surface tailings contained in the Elsburg tailings complex and the L/29 dump. These tailings were estimated to contain some 1.7 million ounces (Moz) of gold.
DRDGOLD acquired part of the Mintails stake in 2008, and the remainder in 2010, giving it a majority share (74%) in the company.
Linking the assets
Ergo’s assets include access to some 750Mt to 900Mt of tailings deposited across the western, central and eastern Witwatersrand. Until recently, the retreatment process was taking place at four plants. Rationalisation and restructuring has resulted in the decommissioning of the Crown and City Deep plants, and their conversion into milling and pump stations. The Knights plant is treating the Cason dump for the foreseeable future. The Brakpan plant – with a 21.6Mt annual capacity – is treating material from a variety of sources, the majority of which is fed to the plant via two feeder lines from the Elsburg tailings complex and the L/29 dump. Another 600 000tpm is pumped from Crown Mines and City Deep via a 62km pipeline which was constructed to link the assets as part of the rationalisation process.
¹ Anglo American Corporation commissioned the Ergo plant in Brakpan in 1977. The operation became part of AngloGold Ashanti in 1998 and was closed by that company in 2005.