S. Africa manganese miners face declining quality issue

Hlengiwe Motaung

South African manganese miners are seeing deteriorating quality in their opencast production and will soon face the decision on whether to expand underground at greater cost, industry officials said.

South Africa, the world’s biggest manganese exporter, has seen the quality of its ore slowly decline from an average of 40% manganese content a decade ago to 37% currently, as the shallow surface of the Kalahari Basin begins to deplete, according to data from the International Manganese Institute (IMnI).

“We are having challenges where in our oxide ores, the manganese to iron ratio is deteriorating, so obviously the iron content in manganese is going higher,” said Andre Joubert CEO of African Rainbow Minerals Ferrous Division at a Project Blue Conference in Johannesburg.

“I think that is creating quite a problem for the smelters and for us as it gets discounted at this type of market that we are currently seeing.”

ARM’s 50% owned BlackRock mine produces 3.7 mt/y of manganese, of which 650,000 t is combination ore and the remainder is high grade ore.

“Some of these open pit mines in the Northern Cape are reaching levels where the strip ratio is going to require them to go underground and that changes the cost of production drastically,” Joubert said.

South Africa has 23 operating manganese mines in the Kalahari basin – 17 open cast, five underground and one that is both opencast and underground, according to data from the Council for Geoscience (CGS).

A CGS official told the conference that there is still a vast amount of untapped manganese on the western side of the basin.

“Western parts of the basin haven’t been touched. From historical drilling that has been done on the basin, there are intersections of the ore beyond 400m and all the way to about 950m below the surface and that is high grade manganese ore, which is still open for future development,” said Asinne Tshibubudze, a CGS scientist.

However, while there is ample opportunity for South Africa to leverage on these reserves, producers will need to be certain of global demand and logistics due to the higher cost of operating underground, Joubert said.

“As you move further away from your main infrastructure, that increases costs,” he said. “With Transnet and the Minerals Council, there is a very delicate balance in terms of the volumes that we should do because it is not going to be in our benefit if we oversupply the market because then you are going to lose margins in the process. So there has to be a disciplined approach and a long-term view of what the steel industry is going to need.”