Diversified miner South32 has boosted its expectations for South Africa manganese production and maintained full-year guidance for all other products after a solid first-half performance.

South32 chief executive Graham Kerr says strong demand and good performance for the company’s South African manganese operations have prompted the company to raise its production forecast by eight per cent.

Meanwhile, total first-half manganese production, 2,830 kwmt, was up 16 per cent on the first half of 2016/17.

“A record quarter of performance and supportive market dynamics have allowed us to increase FY18 production guidance at South Africa Manganese by eight per cent, while production guidance for all other operations remains unchanged,” Mr Kerr said.

The company repeated warnings that US dollar weakness and higher input commodity prices were impacting its costs, particularly for its smelting and refining operations.

Updated cost guidance will be given when the company reports its half-year results.

The company’s share of alumina production for the half was 2.54 million tonnes, down three per cent on the prior corresponding period, while aluminium production was one per cent higher at 495,000 tonnes.

Energy coal production fell 11 per cent in the half-year to 14 million tonnes, with production in South Africa down and domestic sales also lower.

Metalllurgical coal production was down 55 per cent on the prior half at 1.28 million tonnes, largely due to an extended outage at South32’s Appin colliery in NSW and a longwall passing through a fault zone at the Dendrobium mine.

By Peter Trute