The development of an effective method of mining upper ores, which have in the past been excluded from stoping plans, has increased the resource base of the Bimha and Mupani platinum group metals mines, in Zimbabwe, Impala Platinum (Implats) CEO Nico Muller has disclosed.

In response to Mining Weekly at last week’s media roundtable, Muller said Zimplats had previously only targeted ore inclines of under 9º, leaving steep ores unmined. But now it was including the upper ores angled at up to 14º as part of its stoping areas.

That not only enlarged the resource base for Bimha and Mupani but also increased flexibility and improved capital efficiency.

Speaking during the same media roundtable, Zimpats CEO Alex Mhembere divulged to Mining Weekly that the Mupani mine project was actually well ahead of schedule.

“We’re expecting to revise our programme in terms of implementation to bring Mupani forward,” Mhembere added.

In terms of the original schedule, Mupani – which is earmarked to replace the Rukodzi mine that depletes in 2022, and the Ngwarati mine that depletes in 2025 – was due to reach full production of 2.2-million tonnes a year by August 2025, at an estimated total project cost of $264-million. By the end of June last year, $37.8-million had been spent on Mupani.

Mining of the upper ore is also providing increased operational flexibility by increasing the number of attack points as well as improving the overall capital efficiency by using the same infrastructure to mine the bigger volume of reserves.

As a consequence, capital per ounce is reduced and the pressure on future capital investment is eased.

“We’ve also got Bimha progressing very well, on schedule [and within] budget,” said Muller.

The successful redevelopment of Bimha, which suffered a partial collapse some time back, is important in delivering the 6.2-million-tonnes-a-year nameplate ore capacity, which Zimplats is currently achieving.

Zimbabwe Finance Minister Mthuli Ncube told Bloomberg News last week that Zimbabwe no longer stipulated that Zimbabweans had to hold a 50% shareholding in platinum mines and that foreigners would henceforth be allowed to own 100% of mining assets.

“We’re removing that indigenisation rule, which is discouraging foreign direct investment,” Bloomberg quoted Ncube as saying.

In South Africa, the turned-around Implats no longer has the vulnerable balance sheet, negative operational cash flow and huge headcount challenge at the formerly lossmaking Impala Rustenburg.

Of great assistance had been the palladium-rhodium tailwind, which contributed significantly to the company’s financial performance, with rhodium doubling in price and palladium rising sufficiently to cushion platinum’s fall.

While Implats’ six mining operations in South Africa and Zimbabwe are currently all contributing to cash flow, Zimplats has proven to be the lowest-cost producer in the Implats’ portfolio with the highest free cash flow.

Implats expects the current strength in both palladium and rhodium fundamentals to persist for the foreseeable future, with iridium and ruthenium also improving the outlook.

Operating cost is expected to be between R23 900/oz and R24 800/oz of platinum and group capital expenditure is forecast at R4.1-billion to R4.3-billion.