Helsinki-based Metso Outotec, created by a merger on July 1, said its SMD grinding mills could improve the capacity of a slag concentrator operated by Boliden Harjavalta, which last year produced 120,000 tonnes of copper and 26,000 tonnes of nickel.

"At the testing stage, we noticed that slag can be processed very efficiently using SMD technology. Now the slag concentrator can process larger amounts of material, without compromising the targets set for copper recovery," says Timo Sarvijärvi, Metso Outotec's head of mining in the Nordics market area.

The concentrator recovers copper from the slag produced in the copper smelter and returns it to the copper production cycle as high-quality slag concentrate, with grinding an essential part of the process.

Metso Outotec's SMD mills use a fluidised, vertical stirred mill design. The mills utilise the rotational energy of the impeller arms to impart a high-energy motion to the media and slurry mixture inside the mill, according to the company's website.

In a separate news development, the company said following the merger of Metso's Minerals business and Outotec, that the estimated reduction in staff due to a planned reorganisation would be a maximum of 280 out of 2,400 Finland-based employees, with the details to be hammered out by September 2020.