Search this website

Overview

Located on the West Wits Line of the Witwatersrand Basin, near Carletonville, some 70km south-west of Johannesburg in the province of Gauteng, South Africa, Driefontein operates under new order mining rights covering a total of 8,561ha. It is an underground mine with surface reserves represented by rock dumps and TSFs that have accumulated throughout the operating history of the mine.

Driefontein has six operating shaft systems at depths of between 700m and 3,420m below surface, exploiting the Carbon Leader Reef, the Ventersdorp Contact Reef and the Middelvlei Reef, as well as three metallurgical plants.


Driefontein location
SA location
Coordinates
  • 26° 24'00"S
  • 27° 30'00"E

Driefontein has access to the extensive national electricity grid and to water, road and rail infrastructure. Located near regional urban centres where it can routinely obtain supplies, the mine was formed from the amalgamation of the East Driefontein and West Driefontein mines in 1999.

The Driefontein 1 Plant treats underground ore and surface supplemental surface ore with a processing capacity of 240,000tpm. The upgraded CIP circuit at No 1 Plant consists of a semi-autogenous grinding (SAG) mill circuit followed by cyanide leaching, CIP and a central elution facility.

The Driefontein 2 Plant processes SRD material, which is delivered by rail and truck. Throughput is achieved through two SAG mills and a ball milling circuit, cyanide leaching and a CIP plant. A CIL circuit was commissioned in 2014 at No 2 Plant to improve recoveries by replacing the aging CIP circuit.

Driefontein 3 Plant was originally designed as a uranium plant but was converted to process low-grade surface rock in 1998. Similar to No 2 Plant, SRD ore is delivered by rail and truck. The plant has four SAG mills followed by cyanide leaching and a CIP circuit.

Key statistics

    2016 2015 2014 2013
PRODUCTION         
Main development m 13,457 15,704 17,376 17,751
Area mined 000m² 311 384 375 398
Tonnes milled Mt 6.0 5.8 5.4 5.3
Yield g/t 2.70 3.01 3.31 3.5
Gold produced/sold kg 16,130 17,350 17,735 18,775
  000oz 519 558 570 604
COSTS AND MARGINS         
Operating costs R/t 937 907 916 919
– underground R/t 2,374 1,941 1,773 1,750
– surface R/t 182 165 169 165
Operating profit Rm 3,834 3,002 2,917 3,282
Operating margin % 41 36 37 40
Capital expenditure Rm 1,052 994 1,149 1,023
– sustaining Rm 219 249 465 320
– ore reserve development Rm 779 727 684 703
– projects Rm 54 18    
Total cash cost R/kg 355,416 309,764 283,129 265,997
  US$/oz 753 756 814 862
All-in cost R/kg 424,872 373,752 357,333 332,660
  US$/oz 901 912 1,027 1,078
All-in cost margin % 28 21 19 23

Hoisting and production capacities

Operating
shaft
Operational hoisting
capacity (ktpm)
Planned production
ktpm)*
1 105 35
1 SV 105 35
1 T 121 35
6 SV 26 14
2 165 109
4 SV 57 28
8 60 59
5 N/A N/A
5 SV 159 70

* Planned production is five-year hoisted average from 2017 onwards

Plant capacities

PlantDesign
capacity
(ktpm)
Current
operational
capacity (ktpm)
Average
recovery
factor (%)
Material
treated
1 (CIP) 240 240 96.7 UG/SRD
2 (CIP) 200 180 81.0 SRD
3 (CIP) 115 100 81.3 SRD

Performance in 2016

Total operation

Gold production of 16,130kg (518,600oz) was 7% lower than the previous year as a result of lower volumes from underground, which were offset by an increase in surface volumes processed.

Underground

Gold production of 13,919kg (447,500oz) was 9% lower than 2015, predominantly as a result of lower underground volumes, which were affected by shaft infrastructure maintenance. Ore milled at 2.06Mt was 15% lower than the previous year. A relatively stable mine call factor, together with a 13% increase in stoping face values, resulted in a 6% increase in yield to 6.77g/t, which offset some of the volume shortfall.

Main development decreased by 14% to 13,457m, which was slightly below the planned decrease in metres. Development values decreased by 5% to 1,391cm.g/t from 1,468cm.g/t year-on-year.

Operating costs increased by 4% to R4,852 million (US$331 million). This was largely due to annual wage and electricity tariff increases.

The operating profit increased by 25% to R3,253 million (US$222 million) as a result of the improved gold price, partially offset by lower gold production. The operating margin improved to 40% from 36%.

Capital expenditure increased by 7% to R1,048 million (US$71 million) due to an increase in capitalised ORD. Capital expenditure during the 2016 financial year was predominantly spent on capitalised ORD, stabilisation of the shaft barrel at Ya Rona Shaft, the 50 Level decline and shaft steelwork at Hlanganani Shaft, the West Rand Tailings Retreatment Project, and winder and electrical upgrades.

Surface

Higher volumes processed from SRD material at Driefontein resulted in gold production increasing by 10% to 2,210kg (71,100oz).

Throughput increased by 17% to 3.92Mt, partly offset by the lower yield, which decreased to 0.56g/t from 0.60g/t.

Operating costs increased by 29% to R715 million (US$49 million) due to the increase in volumes processed, annual wage increases and higher electricity tariffs. Operating profit increased by 46% to R581 million (US$40 million) due to higher gold production and the improved gold price.

Capital expenditure decreased by 67% to R4 million compared with R12 million spent in the comparable period in 2015. This was mainly due to the completion of CIL in 2015.

Future focus

Focus on safety, mining quality and improvement of volumes, especially at the Masakhane and Hlanganani shafts, will continue.

Finding economically viable alternative surface sources for the Driefontein 2 and 3 plants to process when current material is depleted in 2018, will be another focus area.

Mining on the 50 Level decline at Hlanganani Shaft will also begin in the coming financial year.