Tumela Mine, Thabazimbi, South Africa

The Tumela mine.

The Tumela Mine, located in the Thabazimbi District in Limpopo province of South Africa, contains platinum group metals (PGM). The mine is 100% owned by Anglo American Platinum, which is the world's largest platinum producer accounting for about 40% of world supply.

The mining rights of the Tumela Mine cover a total area of 111km² in the north-western section of the Bushveld Igneous Complex (BIC), which is the largest reserve of PGM worldwide. The life of the Tumela mine extends beyond 2091.

The mine is being operated as a stand-alone unit since 2009 after Anglo Platinum's Amandelbult section was split into two mines, namely Tumela and Dishaba.

Tumela mine's platinum reserves

The Tumela mine produces platinum, palladium, rhodium and gold (4E). As of December 2011, the 4E ore reserves of the mine are reported to be 24.2 million ounces (9.1 million ounces of proved and 15.3 million ounces of probable reserves).

The 4E reserves of the mine were previously reported as 28.3 million ounces in 2010. Following investigations conducted in 2011 to determine maximum mining depths with regard to virgin rock temperatures, 3.4 million ounces of 4E reserves in four shaft portion of Tumela mine were reclassified as mineral resources because of the issues related to mining engineering and complex geology.

The mine also witnessed a production depletion of 0.6 million ounces of 4E during 2010-2011.

Infrastructure of the Tumela mine

"The mine is being operated at a depth ranging between 160m and 850m beneath the surface."

The Tumela mine consists of three vertical and four decline shafts. The mine has two production areas; the Tumela Lower mine and Tumela Upper mine.

The mine is being operated at a depth ranging between 160m and 850m beneath the surface.

Geology and ore details of the Bushveld complex

The Tumela Mine is located in the north-western area of the BIC, which was formed about 2,000 million years ago. The BIC is a huge, geologically unique, saucer-shaped intrusion with a width of 350km, length of 250km, thickness of up to 12km and a total underlying area of 66,000km².

The BIC is rich in platinum group metals with the PMGs mainly concentrated in its two reefs - Merensky reef and Upper Group 2 (UG2) reef. The PGM reserves in the two reefs are estimated to be 547 million ounces and one billion ounces respectively.

Tumela Mine exploits both Merensky and UG2 ore, with more emphasis on the later.

Merensky, whose resources are being extracted since 1925, has suffered depletion during recent years. The UG2 reef, which is found between 16m and 400m vertically down the Merensky reef, now accounts for more than 50% of all the PGM containing ore processed in South Africa.

The UG2 ore contains more chromite but less nickel and copper sulphides compared to Merensky ore.

Mining method at the Tumela mine

Related project

Union Mine, Rustenburg, South Africa

Union Mine is located in the Rustenburg district, 15km west of the Northam town in the Limpopo and North West provinces of South Africa. The mine contains platinum group metals (PMG).

The Tumela Mine uses underground mining method, mostly through conventional breast stoping with strike pillars. The mine also uses remotely controlled drill to install roof bolts which are used to prevent tunnel roofs from falling. Ore is drilled by using low-profile drilling equipments and dumped from the stopes using load-haul-dump (LHD) vehicles.

Tumela's run-of-mine ore undergoes comminution and gravity concentration at Anglo Platinum's amandelbult concentrator plant located near the mine. Subsequently, the smelting, converting and refining of the concentrate are undertaken at Rustenburg Platinum Mines' (RPM) metallurgical facilities.

Production at the Tumela mine

The Tumela mine produced 543,000oz of PMG during 2010-2011. The refined platinum produced by the mine during the year was 264,000oz, an 11% decrease from the previous year.

The tonnes milled at the Tumela mine also decreased by 7%, to 4.2 million tonnes. The decline in production was the result of safety stoppages and low grade ore sources.

"The Tumela mine produced 543,000oz of PMG during 2010-2011."

The mining cost of the Tumela mine increased by 14% to R2.9bn ($342m) in 2011.

The production at the Tumela mine was also hampered in 2012 because of continuous strikes and labour disputes, until they were resolved in November.

The future of the Tumela mine

By the end of 2012, the immediately available ore reserve position of the Tumela mine was stronger than previous, which is likely to improve the production from the mine.

A number of projects are also lined up for the mine, which upon implementation are likely to significantly boost the production in future.

The Tumela 10 West project, which aims at deepening of the existing 10 West decline system and the 16 West belt decline, has advanced from pre-feasibility to feasibility stage.

Feasibility studies on the Tumela Ore Replacement Project (TORP) are also underway. The conceptual studies of Phase 1 of TORP were commenced in April 2012. The phase1 of TORP includes 37 West Incline and 10 West Sub Incline projects, which are expected to produce 1 million tonnes per annum each from 2021 onwards.

Another project, the Central Shaft project, has also been planned to replace Tumela Mines' depleting ore reserves.