Name and Location
South Deep gold mine expansion, Gauteng, South Africa.

Client
Gold Fields.

Project Description
South Deep is a fully mechanised underground mine, extracting a wide multiple band reef at depths of between 2 000 m and 3 000 m below surface. The extraction of such deep-level, wide reefs have not been totally mechanised elsewhere in the world. The production methods used at the mine are, therefore, unique and differ markedly from the labour-intensive mining method traditionally applied in underground mines in South Africa.

The project comprises a main shaft and a ventilation shaft – collectively referred to as the Twin Shaft complex, which will have a combined hoisting capacity of 370 000 t/m of ore.

The main shaft was completed in 2004 and comprises a single drop to a depth of 2 995 m.

The ventilation shaft has been deepened from 2 760 m to about 2 950 m and is fully equipped with ore-storage silos and conveyor belts at shaft bottom, a new rock winder and new headgear.

The mine’s headgear at the vent shaft was completed in 2011 using one of the largest fabricated steel headgear frames in the world.

The South Deep metallurgical plant, which was commissioned in November 2012, has also been expanded and has increased processing capacity from 220 000 t/m to 330 000 t/m.

From 2010 to 2012, the mine completed the construction of the centralised tailings storage facility, developed and installed infrastructure around the shaft systems and changed to full plant tailings backfill for increased production levels. The backfill plant was commissioned in early 2012.

The South Shaft complex will add an additional 120 000 t/m of hoisting capacity to the mine, bringing the total hoisting capacity to 450 000 t/m.

The South Deep operation had a mineral resource of 70-million ounces as at December 31, 2013, and a mineral reserve of 35.1-million ascertained ounces, which will give the operation a life-of-mine until about 2087.

Value
An estimated $4-billion has been invested to date.

Duration
A timeline for the roll-out to steady-state production is still being developed.

Latest Developments
Several important activities had progressed at the South Deep mine mine in the quarter ended December 31, 2015.

Development decreased marginally from 1 486 m in the September quarter to 1 443 m in the December quarter.

South Deep started converting low-profile destress mining cuts to high-profile destress mining cuts towards the end of the September 2015 quarter.

The roll-out of the new high-profile destress mining has progressed well. At the end of the 2015 financial year, all the low-profile destress cuts at the mine had been converted to high-profile, except Corridor 1. About 70% of the mine is employing high-profile distress mining.

High-profile destress mining improved significantly from a low base of 562 m² in the September quarter to 2 990 m² in the December quarter, mainly owing to the introduction of three new drill rigs and improved productivity.

As a result of the transition to high-profile, there has been an expected decrease in destress mining from 9 523 m² in third quarter of 2015 to 7 357 m² in the fourth quarter of 2016.

Secondary support increased by 33% quarter-on-quarter, while backfill placed increased by 25% quarter on quarter.

During 2015 the fleet was optimised and 24 Category 1 machines were delivered to the mine, with all machines, except one, commissioned before year-end. An additional 17 machines will be acquired during 2016.

The maintenance capacity at South Deep improved through 2015, owing to the implementation of the original-equipment manufacturers maintenance contracts in Corridor 2 and the commissioning of the 93 level workshop.

The recruitment of identified critical skills was 98% completed at the end of 2015, with most of the core mining and engineering positions having been filled. With the requisite skills in place, Gold Fields expects further improvements across the mining value chain at South Deep during 2016.

During 2015 a marked improvement in the physical conditions have been achieved across the mine. Further improvements are expected in 2016, particularly through the new underground roadway construction and maintenance project to be initiated in the first quarter of 2016.

Key Contracts and Suppliers
Redpath (backfill piping, battrice panel installation and replacing the South Shaft steelwork); Newrack (secondary support); TWP (metallurgical plant design); AEL Mining Services (supply of explosives for blasting) Atlas Copco and Sandvik (suppliers of HME and spares).

Previous contractors and suppliers:
Murray & Roberts Cementation (mine development and shaft deepening); Wilson Bayly Holmes-Ovcon (WBHO) and Wade Walker (tailings dam); MM&G (steelwork fabrication); Steel Services and Allied Industries, Hatch and Cadhouse Design Enterprises (ventilation shaft headgear); Howden Africa (commissioning of main surface-ventilation fans) and Sarens South Africa and Crane Corporation (overhead crane for the ventilation shaft headgear).

On Budget and on Time?
The project is on budget.

Contact Details for Project Information
Gold Fields VP Corporate Affairs Sven Lunsche, tel +27 11 562 9763 or email media@goldfields.co.za.
Redpath, tel +27 11 974 2051.
TWP, tel +27 11 218 3000, fax +27 11 218 3100 or email twpinfo@twp.co.za.
AEL Mining Services, tel  +27 11 606 0000.
Atlas Copco, tel +27 11 821 9000.
Sandvik, tel +27 11 929 5300.

Previous contractors and suppliers:
Murray & Roberts Cementation, tel +27 11 201 5000.
MM&G, tel +27 11 914 4740.
Wade Walker, tel +27 11 466 0377.
WBHO, tel +27 11 321 7200, fax +27 11 887 4364 or email wbho@wbho.co.za.
Steel Services and Allied Industries, tel +27 18 787 2059 or fax +27 18 787 3416.
Hatch, tel +27 11 239 5300 or fax +27 11 239 5790.
Cadhouse Design Enterprises, tel + 27 16 429 1643 or email info@cadhouse.co.za.
Howden Africa, tel +27 11 240 4000, fax +27 11 493 0545 or email enquiries@howden.co.za.
Sarens South Africa, tel +27 11 861 3800, fax +27 11 861 3899 or email info@sarenssa.co.za.