Environmental Friendly Transformation of the First and Oldest Alumina Refinery in the World

Abstract

Since 2006, Alteo Gardanne Alumina Refinery has launched a significant environmental program to improve its management of bauxite residue as well as wastewater disposal. Red mud from bauxite residue had been sent to the ‘Fosse de Cassidaigne’, a trench in the Mediterranean Sea via a 55 km long pipe, for 50 years. Due to ever improving environmental standards and the need to adhere to new regulations , Alteo rethought its methodology by implementing 3 major operational changes:

• Red mud bauxite residue dehydration with press filters (from 2006) in order to directly stack the residue in a small dedicated area, 4 km away from the refinery

• Suspended solid elimination in wastewater still discharged to the sea with pressure filter technology (since 2016)

• Waste water pH reduction and dissolved metal removal, in particular aluminum and arsenic, by CO₂ neutralization process (planned for 2019) with precipitated solid recycling in the Bayer process.

Further improvements are already under investigation, and will be presented as a conclusion of this environmental friendly transformation of the first and oldest alumina refinery in the world.