AngloGold Ashanti Operations Gold Mine In Region South Africa

      AngloGold Ashanti, one of the world’s largest gold mining have operation mines in nine countries across Africa, South America, and Australia. With significant scale but high all-in sustaining costs, or AISC, AngloGold was geared to generate significant free cash flow during gold’s bull run that ended in 2013. Since the fall in gold prices, management has focused on cutting its AISC.
      Roughly a third of AngloGold’s production is based in South Africa. These underground mines are some of the deepest in the world, and operating costs and safety risks continue to escalate. Furthermore, high labor costs stemming from a unionized workforce historically unafraid to strike and high electricity costs push costs in the region even higher.
      Another third of production is based in Central Africa. These mines have high costs and face added risk from political instability. For example, the company’s Kibali joint venture, expected to provide growth at costs below the company average, is in the Democratic Republic of Congo, which has appropriated foreign mining assets in the past. The remaining third of production is in Australia and the Americas, where the mines exhibit lower costs than their African counterparts and have lower geopolitical risk.
AngloGold Ashanti’s five South African deep-level mines and surface production facilities are divided into three areas of operation: Vaal River, West Wits and Surface Operations. At present, these three areas comprise the following operations:

This is mining operations AngloGold Ashanti in Region South Africa

Vaal River

The Vaal River mining operations comprise three mines located around 170km to 180km from Johannesburg, near the Vaal River on the Free State-North West Province border. These three mines, which share a milling and treatment circuit, are:
  1. Great Noligwa Mine
      Great Noligwa, a mature operation nearing the end of its life, adjoins Kopanang and Moab Khotsong in the Free State. The mine primarily exploits the Vaal Reef by means of scattered mining via a twin-shaft system over three main levels at an average depth of 2,100m. Great Noligwa has its own dedicated milling and treatment plant which applies conventional crushing, screening, semi-autogenous grinding and carbon-in-leach processes to treat the ore and extract the gold. The plant has a nominal throughput capacity of 230,000 tpm
      The reefs mined at Great Noligwa are the Vaal Reef and the Crystalkop Reef, with the Vaal Reef accounting for over 90% of the gold produced in the mine. The Vaal Reef consists of 85% of the ore reserve tonnage with mining grades between 10g/t and 20g/t. In 2008, the Vaal River operations (including surface operations) produced 34,785kg (1,119,000oz) of gold, equivalent to 22% of group production.Production at Great Noligwa fell significantly in 2008 because of a transfer of the SV4 section to Moab Khotsong from where it is more easily accessible.
      The complexity of the ore at Great Noligwa has necessitated a scattered mining strategy comprising a twin-shaft system serving eight main levels at an average depth of 2,400m.The reef is accessed from the footwall haulage and return airway development, with cross-cuts spaced every 180m to the reef horizon.Raises are then developed on-reef to the level above and the reef is stoped out on strike with an average stope width of 150cm. Approximately 4,000m of development is completed each quarter.The orebody is narrow and tabular and averages 35,000m² a month. Panels are on average 26m long.
As the operation ages, mining methods are converting from conventional scattered mining to pillar or remnant mining. Until now the Vaal Reef has been the most economically viable reef to mine. However, as this reef is mined out, the less economical Crystalkop Reef is being increasingly exploited as are economically viable pillars within the mine boundaries.

2. Kopanang Gold Mine
      Kopanang gold mine is located to the west of neighbour Great Noligwa and bound to the south by the Jersey Fault. Gold is the primary output, with uranium oxide produced as a by-product, from a single shaft system to a depth of 2,600m. It almost exclusively exploits the Vaal Reef
    Kopanang exploits gold- and uranium-bearing conglomerates of the Central Rand Group of the Witwatersrand, the most important being the Vaal Reef. Gold is the primary commodity extracted with uranium oxide as a by-product. The Vaal Reef, the primary reef mined, is exploited at depths of between 1,300m and 2,600m below surface. Minor amounts of gold are also extracted from the secondary Crystalkop Reef, located about 250m above the Vaal Reef.
      Given the complexity of the geology, scattered mining is employed and the orebody accessed mainly via footwall tunnelling, raised on dip of the reef and stoped on strike. Kopanang uses conventional semi-autogenously grinding and carbon-in-pulp (CIP) technology to process gold. There are two streams of ore into the plant, one comprised mainly of Vaal Reef ore and the other fed exclusively with marginal oredump material. Roughly 60% of Kopanang’s ore is treated in this plant. The balance is sent to the Noligwa Gold Plant and South Uranium plant by rail for gold and uranium extraction.

3. Moab Khotson Mine

      Moab Khotsong is AngloGold Ashanti’s newest gold mine in South Africa. Stoping operations began in November 2003 with full production achieved in 2010. Given the geological complexity of the Vaal Reef, scattered mining is employed.Moab Khotsong is the newest deep-level gold mine in South Africa. It is situated near Orkney, Klerksdorp and Viljoenskroon, about 180 km southwest of Johannesburg.
      Following the successful exploration of the Vaal Reef in the Moab lease area, which lies to the south and is contiguous with Great Noligwa, a decision was taken in late 1989 to exploit the Moab Mineral Resource. Shaft sinking started in 1991 and stoping operations in November 2003. The mine is scheduled to reach full production in 2013.
      The main shaft is 3,500 m deep – world’s deepest continuous shaft – and was commissioned in June 2002 and the rock ventilation shaft in March 2003. Ore Reserve development on 85, 88, 92, 95, 98 and 101 levels is progressing to plan. Given the geological complexity of the Vaal Reef, scattered mining is employed.In 2011, the mine produced 266,000 ounces of gold.The Moab Khotsong mine is to produce 2.7 million ounces gold over its life of mine which was supposed to end in 2025.
      A feasibility study of the lower mine (Zaaiplaats) was recently completed. The project will exploit the reef to depths of 3,455 m below collar. The projected mine extension would take place and would bring the adjacent Zaaiplaats block into production therefore another 5.4 million ounces of gold would be produced thus extending the mine life to 2037.

West Wits

The two West Wits operations, situated southwest of Johannesburg, on the border between Gauteng and North West Province, are:

1. Mponeng Gold Mine

      Mponeng, the world’s deepest gold mine and our flagship operation in the South Africa region, exploits the Ventersdorp Contact Reef (VCR) at depths of between 2,400m and 3,900m via a twin-shaft system. Ore is treated and smelted at the mine’s gold plant. AngloGold Ashanti’s Mponeng mine is located in Gauteng province of South Africa. It is mined to an average depth of 2,800m-3,400m below surface and is one of the world’s deepest and richest gold mines with grades at over 8g/t. It is one of three AngloGold projects in the West Witts area apart from Savuka and TauTona mines. The name means ‘look at me’ in the local Sotho language.
      Mponeng is located on the north-western rim of the Witwatersrand Basin. There are seven gold bearing conglomerates within the lease area, of which two are economically viable at present. The VCR is a gold-bearing quartz-pebble conglomerate of intermediate grade, capping the last angular Witwatersrand non-conformity.
      The South shaft deepening project commenced in 1996 and as a result Mponeng mines the Ventersdorp Contact Reef (VCR) to the 120 level, which is some 3.4km below datum. Mponeng mines on average at deeper than 2.7km below the surface. The VCR reef that Mponeng mines dips at 22º, and has an average channel width of 78cm.
     The deepest operating stope is at a depth of 3.37km below surface. The grade at this operation varies considerably, therefore a sequential grid mining method is used which allows for selective mining and increased flexibility in dealing with changes in grade ahead of the stope. The mine utilises a twin-shaft system housing two vertical shafts and two service shafts

2. TauTona Mine

      The TauTona mine exists within the West Witts area slightly South West of Johannesburg in the North West of South Africa. “The mine was originally built by the Anglo American Corporation with its 2 km deep main shaft being sunk in 1957, with operations starting in 1962.” TauTona Mine or Western Deep Shaft, is a gold mine in South Africa. At 3.9 kilometers (2.4 mi) deep it is currently home to the world’s deepest mining operations rivaled only by Mponeng gold mine TauTona exploits both the Carbon Leader Reef (CLR) and the VCR via a three-shaft system, supported by secondary and tertiary shafts sinking to depths of between 1,850m and 3,450m. TauTona’s infrastructure is to be used to access the remaining Ore Reserve at the former Savuka mine. A link between the two mines reduces dependency on a single infrastructure system, including ore passes. The integration of Savuka into TauTona has been completed and is expected to extend TauTona’s life of mine. The hoisting of Savuka ore via TauTona is planned to start in the second quarter of 2015.
      The mine consists of a main shaft system supported by secondary and tertiary shafts. The main mining method is longwall. TauTona shares a processing plant with Savuka. The plant uses conventional milling to crush the ore and a CIP (carbon in plant) to further treat the ore. Once the carbon has been added to the ore, it is transported to the plant at Mponeng for electro-winning, smelting and the final recovery of the gold.

Surface Operations

      Surface Operations extracts gold from marginal ore dumps and tailings storage facilities on surface at various Vaal River and West Wits operations. The hard rock business processes hard rock material from underground as well as from marginal ore dumps. Surface Operations also includes Mine Waste Solutions (MWS) which operates independently and processes slurry material reclaimed hydraulically from the various tailings storage facilities. Uranium is produced as a by-product, as is backfill that is used as mining support in underground mined out areas.
     Good progress is being made with the consolidation of the individual operations in each of these areas into three operating entities so as to eliminate any duplication of services and management. This consolidation will have both cost and efficiency benefits. As an initial step in this process, Great Noligwa mine employees have been successfully incorporated with those of Moab Khotsong. The consolidation of the West Wits mines and of Surface Operations is expected to follow in due course.

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