Our most ambitious environmental initiative is at our mine in Paragominas. A program is in place to monitor the local flora and fauna and rehabilitate the mined areas. We aim for one-to-one rehabilitation of previously mined areas that are not used by or reserved for long-term mining infrastructure.
To increase our knowledge and secure a science-based approach to rehabilitation, the Biodiversity Research Consortium Brazil-Norway (BRC) was established in 2013. The consortium is a partnership between research institutions from the State of Pará, the University of Oslo and Hydro. It performs research on biodiversity to improve the rehabilitation process.
Managing bauxite residue
Our operations in Pará have state-of-the-art technology for the treatment and disposal of the significant amount of residue generated by the production of bauxite and alumina, which are traditionally stored in large, engineered storage facilities. Our waste management approach focuses on the mitigation hierarchy: finding ways to avoid, minimize and recycle rather than sending it to a landfill.
Bauxite residue, a waste product of the alumina refining process, is filter pressed and stored in dedicated storage areas at our alumina refinery Alunorte using an enhanced dry-stacking concept. The use of modern press filters results in a bauxite residue with a very low moisture content of only 22 percent which can be more efficiently stored. This new approach means that our bauxite residue now occupies only one fourth of the surface area used per tonne stored than before the introduction of more modern technology.
In 2019, we initiated tests of the novel Tailings Dry Backfill methodology. This allows inert tailings from bauxite mining to be returned to the already open and mined areas instead of being deposited in separate, permanent storage areas. The mined areas are then rehabilitated and reforested. The pioneer application has been in full operation at Hydro Paragominas since late 2021 and eliminates the need to build new dams for permanent storage of bauxite tailings. It is an important advance that brings greater operational safety and economic benefits while responding to the industry's challenge to reduce its environmental footprint.
Turning bauxite residue into a resource
Globally, only 3 percent of the 150 million tonnes of bauxite residue generated annually is recycled. As part of our commitment to minimize operational impacts, we acknowledge the need to push research and development further to explore how to reuse bauxite residue. Research is currently conducted at local, national and international scientific institutions to utilize residue from Alunorte in the production of cement, secondary minerals, aggregate for concrete and soil conditioner, and more.
Research is also underway in partnership with the Federal University of Pará to use tailings from Paragominas in the production of roof tiles, bricks, refractory materials, low-carbon cement, and even biodegradable plastic. We aim to reuse 10 percent of the bauxite residue generated by 2030, and to eliminate the need for new permanent storage areas for bauxite residue by 2050.
In February 2023, Hydro signed a contract with Wave Aluminium to build a plant to process bauxite residue from Alunorte, aiming to recover commercially viable materials from the waste product. When constructed, the plant in Barcarena will initially have the capacity to process 50,000 tonnes of residue per year, delivering on Hydro's vision to contribute to a circular economy.
Managing our climate impact
We are working systematically to reduce our greenhouse gas emissions and our operations in Brazil are key to reach Hydro’s global target to reduce carbon emissions by 10% by 2025 and 30% by 2030, in line with our roadmap to net-zero production by 2050.
One of our most important initiatives is to secure a greener energy mix at Alunorte, one of the largest and already one of the most energy efficient alumina refineries in the world. Hydro has an ambitious program underway that will make Alunorte one of the world’s lowest emission refineries by 2025. This includes installation of new electric boilers, replacing heavy fuel with natural gas by 2024, and further enhancing energy efficiency at the plant. A further step in Alunorte's sustainability roadmap is to phase out coal by 2030.
Planning for a decarbonized future, Alunorte has identified several options to bring emissions down to zero using renewable mineral energy, biomass and hydrogen.
Updated: May 05, 2023