[Mining Weekly] - South African gold-miner DRDGOLD on Tuesday said that it had embarked on a R300-million pipeline and plant expansion project at its Ergo operation that would significantly extend the life of its Crown surface operations.
JOHANNESBURG (miningweekly.com) - South African gold-miner DRDGOLD on Tuesday said that it had embarked on a R300-million pipeline and plant expansion project at its Ergo operation that would significantly extend the life of its Crown surface operations.
Speaking to Mining Weekly Online during a site visit to Ergo, DRDGOLD executive operations officer Charles Symons said that the company planned to construct a 50-km pipeline from its operations in western and central Johannesburg to its Ergo operation on the East Rand. This would give its Crown and City Deep plants access to Ergo’s tailings deposition and could restore the operations to maximum deposition capacity of 600 000 t/m.
"The deposition space at our Crown operations is nearing full capacity, and will reach its limit at around August next year. This project will have to be completed by that date in order for us to start moving the material onto the Brakpan deposition tailings dam at Ergo."
The full feasibility study for the project includes the construction of the 50-km pipeline, pump stations, the upgrading of the tailings dam and the upgrading of the second carbon-in-leach stream at the Ergo operation.
This would double plant capacity to 2,4-million tons a month, reduce costs and improve efficiencies.
Symons indicated that the upgrade of the plant had started and was currently being funded through working profits and capital available in the bank.
However, he said that there would be a shortfall in raising the full amount from profit, but said that DRDGOLD was busy putting in place mechanisms to acquire short-term debt funding to complete the R300-million project.
Symons said that the completion of the project would account for greater operating and cost efficiencies. "We believe that once we have concentrated the treatment costs at our upgraded Ergo operation, we will see an improvement in our extraction efficiency and a reduction in cost, owing to the synergy created between the previously independent plants."
He added that the synergy between the operations did not necessarily equate to retrenchments within the company. "At this point in time, we do not envisage any retrenchments, however, as we get closer to implementing the different phases of the project we will be collaborating closely with the unions.
"In fact, the pipeline project has allowed us to extend the lifetime of Crown and City Deep, which counteracted retrenchments."
The project would not significantly change the amount of gold produced in the company’s portfolio, but would provide the operations with adequate material to operate for the next 12 years.
However, Symons pointed out that the company was running extensive tests on the possibility of increasing recovery of gold from the tailings. "Pilot work that was focused on the releaching of residue, has shown that we could up the yield by around 0,02 g/t, which suggested the potential for about 25 kg/m of additional gold recovered.
"Our big challenge going forward, will be to extrapolate this to the main plant," said Symons.
With the possibility of South Africa investing more in nuclear power stations and DRDGOLD’s surface retreatment operations sitting on a resource that had previously been successfully retreated and sold, the question was raised around the extraction of uranium in the future.
Symons said that the current uranium price at $45/lb to $50/lb was too low to extract uranium at the operation and that the price would have to reach around $113/lb before the company would consider this option. This price also included the refurbishment of the uranium plant on the Ergo site.
"Currently, we are reclaiming the uranium and bringing it to the plant, which means we are already covering some of the costs in the reclamation and the deposition site and we are in a strong position to exploit those advantages in the future," Symons concluded.