Use of Beneficiated Residue Sand (2D3) (4A2) (4A7)

Project Status: Complete
Project Participants: Alcoa, Curtin University of Technology
Project Leader: Evan Jamieson (Alcoa)

The extraction of alumina from bauxites results in the production of bauxite residues that might be further processed into valuable by-products thereby reducing the quantity of residue requiring final storage. These storage areas occupy a significant area of land and require final closure, rehabilitation and ongoing management. Identifying cost effective uses for residue which will ultimately reduce the volume of residue to be stored has long been a key focus area for research and development within Alcoa.

Previous studies into residue re-use suggests that red mud and Red Sand as produced have limitations in terms of direct utilisation, but the application of mineral processing methods may provide some new materials with enhanced utilisation potential.

This project studied the potential to separate and/or beneficiate bauxite residues into different materials using a variety of mineral processing equipment. The residues were characterised by size analyses, x-ray diffraction and chemical analyses. Separations by gravity, magnetic and froth flotation processes were undertaken.

The research objectives were to:

• Determine the impact of the substitution of natural sand with Red Sand and its derivatives as fine aggregate in the manufacture of various grades of concrete. (eg low and high strength as well as marine grade concrete.)
• Determine the impact of the substitution of natural sand with Red Sand and its derivatives as a material for road construction. Uses include as sub base, embankment fill, general fill, and pavement base. A sound understanding of the long term stability is required.
• If comparisons prove unsatisfactory, then determine the specifications for Red Sand and derivatives to enable them to replace natural sand without modification to current construction practices.
• Evaluate combinations of other materials to synergise performance of Red Sand and derivatives for above construction usage.

More Information

• View the "ReSand® Production to Specification" (3B4) project