MOSCOW: Russian aluminium producer Rusal plans to upgrade technology at smelters accounting for 35% of its total capacity within ten years to reduce harmful emissions and power consumption, it said on Wednesday.

Rusal, the world's largest aluminium producer outside China, will replace more than half of cells with newer RA-550 technology at its four Siberian aluminium smelters, its chief executive Evgenii Nikitin told a regional forum in Siberia.

The new cells will have the same total annual production capacity - of 1.4 million tonnes of aluminium. These four smelters in total produced 2.7 million tonnes of aluminium in 2020, or 71% of the company's output.

The 10-year project will start this year, and investments, which the Hong Kong-listed Rusal is yet to disclose, will peak in 2022-2027.

The project may require between $5 billion and $10 billion, the industry ministry of the Siberian Krasnoyarsk region, where the event was taking place, was quoted as saying by Krasnoyarsk.dk news outlet.

Rusal declined to comment.

The project will reduce Rusal's emissions of hazardous substances, including hydrogen fluoride, by 10 times. The new technology will also reduce its electricity consumption by 11-20%, Rusal added.