JOHANNESBURG (miningweekly.com) − Gold Fields has completed the world’s tallest steel headgear, standing at 87 m, at its South Deep Twin Shafts complex, near Westonaria, in South Africa.
The 1 900 t structure, which used 100% South African made materials, has steelwork value of about R40-million and was installed by South African steel provider Steel Services and Allied Industries. gold spiral concentrators manufacturer south africa
Gold Fields contracted Steel Services to supply, fabricate, corrosion protect, deliver and erect a new A-Frame steel headgear over the existing concrete vent shaft headgear. Gold Fields believes that the new headgear will contribute towards extending the life of the mine by well over 50 years.
The design and engineering of the new headgear was done by Hatch. Overall project management of the project was the responsibility of the South Deep vent shaft deepening team.
The new headgear is part of the conversion of the South Deep existing vent shaft into a production shaft that will add another 195 000 t/m rock hoisting capacity for the mine. This, together with the existing main shaft rock winder, will contribute to achieving the mine’s target of gold production of 750 000 oz/y by end 2014. gold processing plant for sale India
Steel Services and Allied Industries group MD Lawrence Bartlett states that, owing to the expected heavy loading on the steelwork, a decision was taken to construct the structure in 1,2 m x 1,2 m x 45 mm box sections.gold processing plant movement sheet
The fabrication and trial assembly of the box section headgear was completed at the Steel Services workshops in Carletonville, and transported the short distance to the South Deep Mine south of Westonaria, where final assembly was carried out in preparation for the headgear erection
The majority of the fabrication was completed in 2010 and the site erection was completed in two stages over the December 2010 and April 2011 shutdowns.
Automatic submerged arc welding procedures was used in the fabrication of the box girders and knuckle joints. All steel was preheated prior to welding to ensure the highest standards in quality and strength were met. All welds were also fully tested. Extensive use of jigs in the fabrication process was used to ensure that the required assembly tolerances were maintained.
“The existing headgear is still in operation and is still required in the daily operations of the mine, which means that destroying it and rebuilding the headgear was also not an option. The only other viable option was to construct a new headgear from steel and erect it over the top of the existing headgear,” Bartlett adds.