Despite experiencing some 67 hours of load-shedding in the last month of 2014, specialist tailings miner DRDGold lifted gold output for the six months ended December 31 by 6% to 73 015 oz, attributing the uptick to increased metallurgical efficiencies at the long-embattled flotation fine-grind (FFG) circuit and the installation in April 2014 of backup power generators.

Strengthened output was helped by an increase in the average yield to 0.196 g/t, reflecting the restoration of metallurgical efficiencies and operating business improvements following the temporary suspension of the FFG circuit in April.

Heavy summer rainfall and load-shedding did, however, cause throughput for the six months under review to retreat by 3% to 11.59-million tons.

While acknowledging concerns over power supply and electricity tariffs over the winter months, CEO Niël Pretorius told shareholders last week that the threat of power cuts and load-shedding was not as serious for the tailings specialist as it was for underground gold producers.

“The current power scenario is entirely manageable for a company like us, but for those that have shift-based underground work, it’s a far more serious situation.

“The installation of backup generators have significantly de-risked [our] operation and will allow us to keep the thickeners [in the circuit] alive,” he outlined.

Further counteracting the power supply risk, DRDGold outlined that Eskom would give the company a two-hour warning prior to load-shedding being implemented in any of the four load-shedding zones in which it operated.

“We have [also] since managed to agree with Eskom for a consumption curtailment agreement, in terms of which we reduce, on request, total consumption by an agreed percentage during load-shedding hours.

“This means that, on the whole, we are able to maintain uninterrupted tonnage throughput but recoveries may reduce owing to certain parts of the operating line going down during the load reduction periods,” he commented.

With load-shedding having become far more frequent in late January and early February, DRDGold is currently testing different scenarios to meet the requirement of reducing its demand.

Typically, in Stage 1 and Stage 2 load-shedding scenarios, the miner is required to reduce power consumption by up to 10% of baseload, while Stage 3 would require a 20% decrease.

“This [agreement] is working for us at this stage,” Pretorius noted.

DRDGold outlined further in its report to shareholders that planned testwork on the FFG circuit had dominated the work programme at Ergo’s Brakpan plant in the last quarter of the year.

The return of operating circuits to steady state in the preceding five months provided both a base case from which the company could track the performance of the FFG circuit, and allowed it to do the required work in a “measured” way.