JOHANNESBURG (miningweekly.com) – Impala Platinum (Implats) has completed the commissioning of the new No 16 shaft complex at its Impala Rustenburg operation, in the North West.

The R6.9-billion shaft complex, on which construction started in October 2004, would enable Implats’ Rustenburg operation to access new ore reserves and maintain a stable production profile, reaching 185 000 oz/y of platinum at full production in 2018.

The new large-scale infrastructure and superior grade would also allow the platinum miner to mine at an improved overall cost to the current cost average for the Rustenburg operations.

Implats CEO Terence Goodlace said on Friday that preparations for mining operations would start immediately, with first stoping expected to start in the September quarter.

“The new shaft complex ensures that Implats remains in an excellent position to benefit from the long-term platinum group metals market fundamentals in an industry in which the supply side is being constrained by a lack of investment,” he said.

Goodlace added that the new complex, which offered a 25-year mine-life, would also secure jobs for 6 500 workers currently employed at the older-generation Rustenburg shafts.

The No 16 shaft infrastructure, which was designed to support mining operations from seven mining levels at a rate of 226 500 t/m of reef, boasted the tallest known concrete headgear in the world, at 108 m.

The system consisted of a 10-m-diameter main hoisting shaft, which was 1 675 m deep, and a 6.8-m-diameter, 1 440-m-deep ventilation shaft.

The seven levels of the main shaft would access both the Merensky and upper group two reef horizons, with the emphasis on mining the Merensky reef during the initial ramp-up hoisting phase.

Mined ore would be hoisted by a rock winder and then hauled to the existing mineral processing infrastructure currently used at Implats’ Rustenburg operations.

Implats projects executive Gerhard Potgieter explained that the new shaft was the second of several fourth-generation Impala shafts, which had been allocated the majority of Implats’ capital expenditure programme over the last few years.

“The first shaft to be commissioned at Implats was the No 20 shaft complex in 2012, making the No 16 shaft the second to be commissioned. The No 17 shaft remains under construction,” he commented.

The combined impact of these new shafts was forecast to, over the next five years, increase the ratio of Merensky reef milled from the current 43% of total throughput to 50%, owing to the exploitation of reserves at the new No 20 and No 16 shaft complexes.