Location and History

Lefa

Our Lefa mine is some 700 km north east of Conakry, the capital of the Republic of Guinea and is connected to an all-season road that has easy access to an air strip.

Commercial production began at the Lefa mine in 2008. The mine was acquired by Nordgold at the end of July 2010, as part of the Crew Gold acquisition, with financial results consolidated from August 2010.

Lefa gold mine operates a typical modern open pit operation with three major mining areas and several smaller, higher grade satellite pits, which will provide supplementary feed for the mill over the life of the project.

Lefa continued its strong performance in 2015. The mine increased gold output by 4% YoY to 214.2 koz due to the improvement of all mining and processing parameters.

Operating and Financial Highlights

2015 2014 2013 2012 2011 2010
Run of mine (kt) 24,999 18,144 23,934 26,986 23,933 5,829
Waste mined (kt) 18,980 13,945 20,054 20,674 17,273 3,430
Ore mined (kt) 6,019 4,199 3,880 6,312 6,660 2,327
Stripping ratio (tn/tn) 3.2 3.3 5.2 3.3 2.6 1.7
Ore processed (kt) 6,558 6,459 5,826 5,932 6,128 2,186
Grade (g/t) 1.15 1.13 1.06 1.07 1.13 1.19
Recovery (%) 88.3 86.8 83.5 84.1 85.5 88.6
Gold production (koz) 214.2 205.1 162.7 171.9 195.7 73.3
Gold sold (koz) 223.5 195.7 162.7 171.9 195.7 73.3
Average realised gold price per ounce sold (US$/oz) 1,164 1,262 1,387 1,670 1,554 1,346
Revenue (US$/m) 260.1 247.0 225.7 287.1 304.1 98.6
EBITDA (US$/m) 118.7 62.6 (13.1) 75.8 108.0 25.7
Total Cash Cost (US$/oz) 643 850 1,398 1,180 861 860
AISC (US$/oz) 832 1,122 1,622 - - -
  • Notes:
    • Nordgold obtained a controlling interest in Lefa mine at the end of July 2010. Figures for 2010 represent only the period after Crew Gold was acquired by Nordgold, i.e. from August to December 31, 2010, while the 2011 column represents the full-year operations of Crew Gold as part of the group. All the changes in 2011 in comparison to 2010 are explained by the different periods of operations as part of the group in 2010 and 2011.

Ore Reserves and Mineral Resources Summary (31 December 2015)

Category Ore (Kt) Grade (g/t) Au (Koz)
RESERVES
Proven and Probable 62,177 1.50 3,003
RESOURCES
Measured and Indicated 87,569 1.38 3,893
Inferred 23,103 1.21 901


For more information, please see Mineral Resources and Ore Reserves Press Release

Technology

Lefa consists of two main open pits and several smaller satellite pits, an eight-kilometer conveyer belt from Lero-Karta pits to the processing plant, a processing plant with a crushing circuit, two SAG mills, two ball mills and a CIP circuit, waste rock dumps, a specially constructed tailing storage facility, and a water management system.

Milling and Classification
Nordgold’s open pit operations use conventional surface mining methods involving drilling and blasting, followed by a load and haul process allowing for selective mining of the ore. Ore from the pit is then transported to a designated stockpile and fed into a crushing circuit. The crushed material is then moved onto a conveyor, which delivers the ore to a grinding circuit consisting of SAG and ball mills. The milled product is then thickened and leached into a CIP circuit.
Cyanide leaching and sorption
The cyanidation of the milled ore is carried out in the CIP or CIL circuit. During the CIP or CIL stage, pulp flows through several tanks where sodium cyanide and oxygen have been added to dissolve gold into solution. In the absorption stage, this solution flows through several tanks containing activated carbon. Gold then attaches onto the activated carbon, which flows counter current to the pulp, while screens separate the barren pulp from the gold-loaded carbon.
Elution
The final gold loaded carbon is removed and washed before undergoing elution. Elution is achieved by introducing the gold loaded carbon to a solution of sodium cyanide at a high temperature (>110°C) and under high pressure. This results in the reversal of the attachment process, with the gold detaching from the carbon back into solution. This produces a small volume of solution with a high gold concentration.
Electrowinning
The gold loaded eluate solution that emerges from the elution process is passed through electrowinning cells, where gold is deposited onto the cells’ cathodes.
Smelting
The cathodes then undergo a smelting process, further refining the gold and leading to the eventual production of gold ingots suitable for transport to a refinery.

2016 Deliveries

  • Lefa will continue to target higher ore volumes mined and a slight increase in head grade. The plant productivity and ore blend consistency will improve further in 2016 due to the reclaim feeder, which was launched in December 2015, despite processing harder ores.
  • 2016 operational improvements will also include LoM ore feed and plant design optimisation, upgrade of the pebble crusher and powerhouse, and the investment by Q4 2016 in a new oxygen plant for leach area to replace peroxide addition.
  • The 2015 drilling programme was designed to define resources to extend the Kankarta pit life and has yielded economic intersections in a significant number of holes that should produce additional resources after infill drilling that will take place in 2016.
  • Lefa will continue to pursue ore reserve replacement from early stage exploration, extensional exploration and Mineral Resource conversion drilling in current pits.
  • The mine also continued the search for new deposits near existing operations.

CONTACTS

Olga Ulyeva


Head of Media Relations
tel.+7 495 644 44 73 #707 6632

ROMAN MEZHUEV

RECRUITMENT MANAGER
tel.+7 495 644 44 73

OLEG BAZALEEV

HEAD OF SUSTAINABLE DEVELOPMENT PROJECTS
tel.+7 495 644 4473 #707 6746