Project Status: Complete
Project Participants: Alcoa
Project Leader: Evan Jamieson (Alcoa)
The extraction of alumina from bauxite ore results in the production of bauxite residues that are typically alkaline in nature, making subsequent use difficult. In Western Australia, Alcoa has three operating alumina refineries (Pinjarra, Wagerup and Kwinana) producing large volumes of residue mud and sand that are stored in secure impoundments. Alcoa has implemented a process to carbonate the residue in order to remove alkalinity and turn the residue into a useful by-product.
Recent research has identified methods of separation of ReSand® from bauxite residue , its neutralisation through carbonation and its ability to be washed low in salt.
During 2007/08, a pilot plant was constructed, commissioned and is in operation to demonstrate separation, washing and carbonation processes. The 10 tonne per hour pilot plant provided sufficient quantities of clean neutralised ReSand® suitable for major product demonstrations. The locality of Alcoa's refineries has been a contributing factor in identifying large volume local markets for clean sand.
This project followed on from the earlier CSRP projects on the “Use of Beneficiated Residue Sands” (4A2 and 4A7) which are now complete and identified the potential for various beneficial uses of bauxite residue fractions.