The production target for Westonaria-based South Deep gold mine, in Gauteng, is expected to be marginally lower next year than initially stated in the miner’s rebase plan, owing to a challenging first quarter this year, notes Gold Fields CEO Nick Holland.
South Deep is the sole South African asset of gold major Gold Fields.
The South Deep rebase plan, launched in March, is a long-term plan focused on ensuring the mine’s sustainability and future relevance in the globally changing environment of gold mining.
The rebase plan forecast that, in 2018, South Deep would be set to produce 11.1 t of gold, but Holland notes that two fatalities and a fall-of- ground incident earlier in the year will impact on future guidance figures. In this regard, he says the 2018 targets should be considered with a “haircut” of between 5% and 10% of the 11.1 t volume. This lowered production figure is in line with South Deep’s amended production figures after the first quarter of this year.
Despite the sequential quarter-on- quarter improvement in production in the second and third quarters at South Deep, he says the mine will be unable to recover the full extent of the first-quarter loss. As a result, full-year production from the mine is expected to be between 5% and 10% below the original guidance of 315 000 oz for 2017.
Holland also highlights that two high-grade areas of the mine required rehabilitation following two fatalities. During this time, these areas could not be mined, hence impacting on production, with lower-grade material being mined until the high-grade areas could be stabilised and mining operations restored.
However, there was an improvement in production in the third quarter (Q3), on the back of an improved second quarter (Q2), owing to the miner having been able to resume mining through access to the high-grade areas. Going into the fourth quarter (Q4), Holland says, gold production is up 10% on Q3 to 81 000 oz, driven by a 10% increase in underground reef grade to 6.34 g/t.
He adds that there will be no additional risks going into Q4 and in 2018, as any identified risks will remain the same as or similar to those posed over the past year.
However, going forward, plans to ensure that the mine remains on target are being implemented to ensure sufficient volumes are mined and processed. Holland points out that the core focus on enhancing the operational value chain is ensuring efficiency throughout the mining process – from drilling and blasting in the prescribed fashion, undertaking ground support timeously and cleaning up stopes quickly to timeously tramming ore into hoists, where it is extracted from the shafts and transferred to the processing plant.
“This involves honouring the entire value chain. We have been working quite hard on doing that over the year, which is part of the reason for the improvements in Q2 and Q3. We are hoping to achieve an improvement again in Q4,” states Holland.
In Q4, thus far, Holland notes, South Deep is “reasonably on track” to achieve its quarterly production target. “We can always do a lot better, but I think we have carried forward a lot of the momentum we had in Q3.”
In addition, he notes that destress volumes are earmarked for a 50% increase on those achieved in the third quarter. “The target for Q4 is 3 000 m2 to 3 500 m2. The purpose of this is to try to open up as much space as possible.”
However, Holland is concerned that the poor destress performance earlier in 2017 is impacting on the extent to which South Deep is opening up space: “[There] has not been as much space as we would like.” This, he says, will result in a knock-on effect for the 2018 targets.
These short-term performance impediments are unlikely to impact on the long-term integrity of the rebase plan because South Deep has six years to build up to its steady-state production target of 230 000 t/m, Holland explains. Currently, South Deep mines about 135 000 t/m.