Kusasalethu Gold Mine

South Africa / Gauteng / Carltonville /
 mine, gold mine

This is the mining right for the Kusasalethu Gold Mine which was originally built and owned by Anglo American, and at the time of Anglo ownership was known as Elandsrand Gold Mine. Anglo sold the mine to Harmony Gold in February 2001 in a R1 Billion cash deal that also included the neighboring Deelkraal Gold Mine that Anglo acquired from Goldfields in 1997. In 2010 Harmony changed the name of the mine to Kusasalethu, which in zulu is translated as “our future”. The current mining lease was converted to a new order mining right at the Mineral and Petroleum Resources Titles Office as GP30/5/1/2/2/07MR and is valid for the date range December 18, 2007 through to December 17, 2037.

Since operating the mine Harmony has encountered many operation problems and issues such as low grades, labour disruptions, fires, and illegal mining activities. In 2016 they announced that only the remaining high grade ore would be mined and once depleted the mine would be closed. That changed the life of mine from 24 years to 5, chopping off 19 years of production and employment mining the lower grade ores.

Kusasalethu started production in 1978 and the shaft infrastructure is comprised of twin surface shafts and twin sub level shafts to access the deeper levels of the mine. Both surface shafts have a diameter of 10 m, with the rock/ventilation 2,195m deep and the man/material shaft 2,127m deep. The sub vertical rock/service shaft reaches a depth of 3,318m and the sub vertical ventilation shaft a depth of 3,388m. Both were originally 3,048m deep but Harmony deepend them as part of the new mine project to mine higher grade ore. In December 2014 operations were suspended in the old portion of the mine above 98 level.

Mining is conducted on the Ventersdorp Contact Reef at depths of 1,600 to 2,800m below surface in the old mine, and up to 3,300m deep in the new mine. The sequential grid mining method is used with regional dip stabilising pillars, backfill and pre-conditioning to offset the effects of mining at the depths of levels 98 through 113. Clamping pillars are used to stabilize large geological structures encountered underground.

Mined ore is gravity fed from the shaft main ore pass system to the 115 level on rail equipment. It is then hoisted using the sub level rock/service shaft to above the 73 level, then it is transferred by conveyor to 73 level, then gravity fed to 77 level. From there is is hoisted to surface using the rock/ventilation shaft. That ore is moved to the gold plant where gold is extracted using the typical methods of milling, cyanide leaching, carbon-in-pulp concentration and electrowinning to absorb the carbon and produce doré. Doré is then transported to the Rand Refinery twice a week for smelting.

Regionally Kusasalethu is located in the Witwatersrand Basin which is a late Archean-aged basin that is comprised of an inter-bedded sequence of arenaceous and argillaceous sediments. The basin is located on the Kaapvaal Craton and is 6 km thick, 300 km wide from northeast to southwest, and 100 km wide northwest to southeast. All sections of the basin except the northern section are overlain by 4km of volcanic and sedimentary rocks from the Archaean, Proterozoic and Mesozoic period.

Locally the Ventersdorp Contact Reef, the Carbon Leader Reef, and the Mondeor Reef are present at Kusasalethu but only the Ventersdorp Contact Reef is mined as the other zones are not considered economic. Both the Ventersdorp Contact Reef and Carbon Leader Reef are narrow, tabular ore bodies typically 0.2–2m thick and are comprised of quartz pebble conglomerates hosting gold, with extreme lateral continuity.
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Coordinates:   26°27'34"S   27°22'20"E
This article was last modified 6 years ago