Gold Fields Extending South Deep Ventilation Shaft

Two schematic views of the Twin Shaft complex at Gold Fields’ South Deep gold mine in
South Africa show the approximate layout (above) of the complex and the phasing of production
from the 30-million-oz reserve base (below). (Illustrations courtesy of Gold Fields)

Gold Fields reported on April 21, 2010, it has started the depth extension of the South Deep Ventilation Shaft, a crucial milestone in the development of its South Deep mining complex in South Africa. The ventilation shaft is the second of the two shafts that together form the Twin Shaft complex at South Deep. The first shaft, the Main Shaft, was completed in 2004.

The ventilation shaft will be extended from its current depth of 2,760 m to 3,000 m. The deepening and equipping of the shaft, which includes ore storage silos and conveyor belts at shaft bottom, a new rock winder, and new headgear, is set to be completed by July 2012.

The Twin Shaft complex currently has a hoisting capacity of 175,000 mt/m through the Main Shaft. This is set to increase to 370,000 mt/m (comprising 330,000 mt of ore and 40,000 mt of development waste) once the Ventilation Shaft is completed. The completion of the Ventilation Shaft and the commensurate increase in production capacity of the Twin Shaft complex will enable the mine to build up to its full production target of between 750,000 and 800,000 oz/y of gold by the end of 2014.

Gold Fields has allocated R8.5 billion (in current money terms) to be spent before the end of 2014 on developing the South Deep mine. In addition to the deepening of the shaft, the funds will be used for developing a new tailings facility; an upgraded metallurgical plant to increase the milling capacity from 220,000 mt/m to 330,000 mt/m, with an option to expand it further to 450,000 mt/m by 2013; development and installation of infrastructure around the shaft systems; change to full plant tailings backfill for increased production levels; refrigeration and ventilation installations; and development and opening up of the orebody in preparation for mining.

“The South Deep capital program is well resourced and tightly managed. We have made good progress nearing the end of the second year of our six-year program, and we are confident we will achieve our full production target by the end of F2014,” Gold Fields CEO Nick Holland said. “South Deep is on track to become one of the world’s most productive, mechanized deep-level gold mines.”

South Deep, which, at approximately 30 million oz, has one of the largest reserves bases of any gold mine, was acquired by Gold Fields in 2007.

As featured in Womp 2010 Vol 04 -