Mponeng Gold Mine

 mine, production, gold mine

This is the Mponeng Gold mine, and it is one of the three Western Deep Levels mines of the West Wits gold field which is currently the West Witts Operations owned by AngloGold Ashanti. The first known organisms that live totally independently of the sun were discovered deep in this mine, see the details at bottom of article. There is also a picture attached the shows the organism.

AngloGold Ashanti’s Mponeng mine in the North West Province of South Africa is one of the world’s deepest and richest gold mines with grades at over 8 g/t. It is one of three AngloGold projects in the West Witts area. The name means ‘look at me’ in the local Sotho language.

Formerly the Western Deep Levels South Shaft, or Shaft No 1, Mponeng is the most recently sunk of the three former Western Deep Levels mines. Sinking of Mponeng shafts began in 1981, and the main shaft was completed in 1986, with the subshaft completed in 1993.

"Mponeng is the most recently sunk of the three former Western Deep Levels mines."Production at Mponeng declined by 2% to 587,000 ounces in 2007 compared with 596,000 ounces in 2006. This was due in the main to the various planned and unplanned work stoppages and safety initiatives conducted towards the end of the year, as well as a decline in grade and reduced face advance.

Currently all production is sourced from the VCR (Ventersdorp Contact Reef), however, work is underway to extract ore from the Carbon Leader Reef (CLR) below it.

The CLR below 120 project is aimed at accessing the CLR located about 900m below the VCR. Work is currently under way on the feasibility study for this project.

AngloGold says that initial data indicates the project has the potential to contribute 6.8Moz to production at a cost of R7.5bn ($1.1bn).The project is to be presented to the board for formal approval in October 2008 and is due to begin in January 2009 with production scheduled to start in 2017.

The other major project, VCR below 120, entails accessing the mineral reserves below 120 level. AngloGold Ashanti estimates that this project will add 2.5Moz to production at a cost of R2.03bn ($252m). The project was approved by the board in February 2007, following which construction began. On-reef development and thus the start of production are scheduled for 2013 with full production due in 2015.

Some 5126 people were employed full time at Mponeng in 2007 with 435 contractors. This is around 250 more than were on the books in 2006.

"AngloGold says that initial data indicates the project has the potential to contribute 6.8Moz to production at a cost of R7.5bn ($1.1bn)."Geology and reserves

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.

Proved reserves at the Ventersdorp Contact Reef are currently at 653,000 ounces with 5.5 million ounces probable reserves. The yet-to-be-mined CLR below it contains an estimated 4 million ounces in probable reserves.

Mining

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.

Ore processing

Ore mined is treated and smelted at Mponeng’s gold plant. The ore is initially ground down by means of semiautogenous milling after which a conventional gold leach process incorporating liquid oxygen injection is applied. The gold is then extracted by means of carbon-in-pulp (CIP) technology. The plant conducts electro-winning and smelting (induction furnaces) on products from Savuka and TauTonaas well.

"The plant conducts electro-winning and smelting (induction furnaces) on products from Savuka and TauTona."Production and costs

Production in 2007 fell 2% to 587,000 ounces compared with 2006.

The various planned and unplanned work stoppages and safety initiatives conducted towards the end of the year, combined with a decline in grade and reduced face advance, contributed to the decrease in production.

There was a 4% decline in the area mined in 2007, largely as a result of a 3% decrease in face length. Mponeng undertook extensive cost cutting measures throughout the year.

Production in 2008 is projected to be in a range of 436,000oz to 460,000oz, a decrease of 20% at a total cash cost ranging from $US278/oz to $US288/oz. Capital expenditure of R568m ($US73m) is planned, to be spent mostly on the VCR below 120 level and CLR below 120 level projects.


Gold mine holds life untouched by the Sun:

19:00 19 October 2006 by Debora MacKenzie

The first known organisms that live totally independently of the sun have been discovered deep in a South African gold mine.

The bacteria exist without the benefit of photosynthesis by harvesting the energy of natural radioactivity to create food for themselves. Similar life forms may exist on other planets, experts speculate.

The bacteria live in ancient water trapped in a crack in basalt rock, 3 to 4 kilometres down. Scientists from Princeton University in New Jersey, US, and colleagues analysed water from the fissure after it was penetrated by a narrow exploratory shaft in the Mponeng gold mine near Johannesburg, South Africa. The shaft was then closed.

Reference for Location:
tracks4africa.co.za/maps/w184948/

Reference for information:
www.mining-technology.com/projects/mponeng/
www.anglogold.co.za/subwebs/InformationForInvestors/Rep...
www.anglogold.co.za/About+our+business/Our+operations/S...
www.womp-int.com/story/2010vol05/story024.htm

science.discovery.com/tv/build-bigger/projects/mponeng-...

www.newscientist.com/article/dn10336-gold-mine-holds-li...
www.deepscience.org/contents/dark_life.shtml