Power tariff increases of 24,8%, 25,8% and 25,9% for the next three years, starting next month, will see electricity costs as a portion of Gold Fields’ total operating costs increase from 12% to an esti- mated 20%, says Vishnu Pillay, the gold major’s vice-president for South African operations.

The National Energy Regu-lator of South Africa recently granted Eskom permission to effect these price increases. The power utility had sought con- siderably higher increases.

Pillay says that the impact of the power tariff increases on Gold Fields production costs is being monitored carefully and that various power conservation programmes are in place to reduce power consumption.

Meanwhile, Pillay says that ore reserve development at all Gold Fields conventional opera-tions is being accelerated with the mechanisation of all flat-end development at the long-life shafts using a variety of track-mounted drill rigs. Work is also continuing to develop mechanised equipment for in-stope drilling to reduce the risk exposure of operators.

Gold Fields’ South Deep mine, in Johannesburg, became a fully mechanised operation in March 2008. Mechanised horizontal destress mining, mechanised drift and fill, and longhole stope mining are some of the deep-level mining methods currently employed at South Deep.

“In general, mechanised mining will improve safety and cost effectiveness at the mines. Further, significant progress has been made on the research into an underground tracking system, comprising a real-time locating system that monitors the underground position of personnel and self-propelled mobile machinery,” he says.

As safety is Gold Fields’ top priority, the company will continue to strive towards zero harm by mining only where and when it is safe to do so, says Pillay. In terms of deep-level mining, the company seeks to improve safety and expand its operations in line with growth forecasts.

Several initiatives have been introduced to tackle fall-of-ground incidents caused by gravity and seismicity. This includes centralised blasting, the installation of in-stope netting, umbrella packs and roof bolting as well as the preconditioning of the stope face.

Fall-of-ground incidents as a result of seismic events and gravity are the biggest causes of fatalities at Gold Fields at present. Remedial measures include an increase in regional support pillars, the exclusion of high-risk pillars from the mineral reserve inventory and an increase in in-stope areal support.

Pillay explains that increasing depths result in challenges caused by a progressive rise in temperature and rock stress, and that it becomes increasingly complex to provide the logistics required as distances from existing shaft systems increase. As a result, operating costs rise and the time that can be spent at the mining face is reduced.

Rising temperatures at the rock face necessitate the installation of appropriate ventilation and refrigeration infrastructure to ensure that safe, acceptable environmental conditions are maintained.

Another challenge is the increasing transport distances, where lines of logistical support are extended, resulting in increased costs and a reduction in the time spent at the rockface.

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