Evander Mines exploits the Kimberley Reef in the Evander basin, the eastern-most extremity of the Witwatersrand Supergroup. The Kimberley Reef is mined throughout the major gold mining districts within the Witwatersrand Supergroup, including the East Rand, Central Rand, West Rand, Far West Rand and Free State goldfields. Deposition models for gold within the conglomeratic horizons follows a palaeo-placer-type sedimentological deposition along with winnowing, erosion and concentration of gold-bearing footwall lithologies. Various studies have highlighted the importance of hydrothermal activity for deposition, remobilisation and enrichment within certain packages of the Witwatersrand Supergroup.

The Kimberley Reef is an oligomictic, pebbly conglomerate and comprises a composite sequence of channel sediments that define longitudinal gravel bars and sand bars with pebbly veneers. The reef in the area strikes in an east-west direction and dips to the north at about 10 degrees. The area is also divided by two major normal faults, striking in an east-north-east to west-south-west direction. The reef thickness varies from a waste on contact up to a 50cm well-developed oligomictic conglomerate. Average reef thickness is 35cm within the 8 Shaft vicinity. High gold values in the Kimberley Reef are mostly located at the base of the unit and are associated with the presence of carbon and some visible gold on the footwall contact.

Palaeo-placer and braided stream-type sedimentary deposit scavenged gold from the hinterland and underlying deposits. Mineralisation is concentrated in robust conglomeratic and carbonaceous units.

Gold is associated with disseminated sulphides in the form of pyrite. High grades occur where the reef is characterised by carbon specs or bands.

The goldfield is centred around Evander, a town founded in 1955 to serve the burgeoning mining community. The first gold to be produced came from Winkelhaak Mine in December 1958 and, over the next nine years, three other mines were brought into production, namely Leslie Mine, Bracken Mine and Kinross Mine. Evander Mines (Leslie, Bracken and Kinross Mines) exploits the Kimberley Reef, where mining methods employed include underground conventional breast-type scraper mining and railbound equipment with some trackless mechanised development.

The current revenue streams for Evander Mines are primarily generated from Evander Mines’ 8 Shaft (8 Shaft) pillar mining and Elikhulu.

8 Shaft is an underground complex consisting of vertical and decline shaft systems. Gold-bearing reef is mined from 8 Shaft pillar, approximately 1.6km below surface and from 24 Level, some 2.4km below surface. Ore is transported through the decline shaft systems to 15 Level. From there, the ore is transported across to Evander Mines’ 7 Shaft (7 Shaft), where it is hoisted and conveyed to the Kinross metallurgical plant.

Evander 8 Shaft mining method is footwall development to reef horizon and then developing on reef horizon (raise). The mining follows an upside down Christmas tree sequence to extract the reef horizon. Old areas of the mine are also cleaned up by means of vamping activities.

The Evander Gold Plant (also referred to as the Kinross Gold Plant) is situated in the town of Evander, in Mpumalanga Province, South Africa, approximately 134 km east of Johannesburg. The plant treats ore from Evander No. 8 Shaft and old tailings etc.

There are six SAG mills operating in closed circuit with a hydro cyclone. A portion of the cyclone underflow is directed to Knelson centrifugal concentrators for the recovery of free gold. There is one Knelson concentrator for every two milling units. The milled product is nominally 80% passing 75 microns. The mill section is noncyanide exposed as it utilises non contaminated underground water for dilution and gland service water.

The cyclone overflow is directed, via linear screens, to five thickeners (of which two are utilised for the current throughput). The thickened pulp is transferred to the leach, CIP/CIL, circuit via a surge tank into which liquid sodium cyanide is added. The leach configuration is based on ........