Hydro’s alumina refinery Alunorte has received the suspension of the embargo on the new bauxite residue deposit area (DRS2) from the Brazilian federal environmental agency Ibama. However, the embargo from the federal court system remains in place.
Ibama lifted the embargo on DRS 2 after reviewing the information requested from Alunorte and Semas, the local environmental agency in the state of Para. The decision to lift the embargo follows an exceptional authorization granted by Ibama to Alunorte on 5 October to utilize its state-of-the art press filter technology in processing of bauxite residues. Using DRS2 in combination with press filter technology represents the only long-term sustainable solution for Alunorte.
The suspension of the embargo by Ibama does not allow for an immediate resumption of DRS 2 testing and commissioning phase, as the embargo from the federal court remains outstanding.
“The new bauxite residue deposit, together with the press filter, is the world’s most modern bauxite residue treatment technology. We will continue the dialogue with the authorities to seek the permission to utilize the new deposit area, as this is fundamental for the sustainability and continuity of the refinery's operations", says Hydro’s executive VP of Bauxite & Alumina, John Thuestad.
DRS2 is purpose-built to safely store bauxite residues processed by the press filters, which significantly reduces moisture in residue material, enabling it to be dry stacked and thereby reduces the required storage area. This leads to improved environmental footprint of the storage area and increases safety.
Alunorte initiated the project to migrate operations to the new press filter technology in DRS 2 in August 2014. Prior to the embargos imposed in March, the refinery was in the process of commissioning of the press filters and DRS2, with the intention to gradually ramp-up while simultaneously reducing the use of drum filters and the old DRS1 deposit area. The resumption of commissioning and tests activities on DRS 2 would allow Alunorte to make the planned transition from DRS1 to the new residue deposit and to the new technology.
“This is a development in the right direction for Alunorte, bringing us one step closer to our original plan of replacing DRS1 with DRS2, based on modern press filter technology,” says Thuestad. “In a longer-term perspective, using press filters in combination with DRS2 represents the only sustainable solution for Alunorte – environmentally as well as operationally,” says Thuestad
The timing for when the embargos limiting Alunorte’s production to 50% of full capacity may be lifted remains uncertain.