Norsk Hydro ASA said Oct. 5 that it secured approval from Brazilian federal environmental agency IBAMA to use a press filter for processing bauxite residues, which will extend the life of its bauxite residue deposit area one and enable its Alunorte alumina refinery to restart at 50% capacity.

This comes days after the Norwegian firm said it would suspend production and lay off workers at Alunorte, as the residue deposit area on the site was close to reaching its capacity.

John Thuestad, head of Norsk Hydro's Bauxite and Alumina business area, said that "we are ready to restart our operations ... We are now making every effort to go back to producing as we maintain our dialog with authorities to resume full production".

Resuming 50% production at Alunorte will also enable Norsk Hydro's bauxite mine Paragominas and its joint venture primary aluminium smelter Albras to continue operating at half capacity, as opposed to being fully shut down due to Alunorte being idled, Thuestad added.

Alunorte will be working with the Secretary of State for Environment and Sustainability, or SEMAS, to obtain the authorization to use the press filter on residue deposit area one. This filter provides stackable residues with considerably less water content than a drum filter.