Reprocessing tailings at Worsley Alumina to unlock value

At Worsley Alumina, bauxite residue is the waste created during the alumina production process which is discharged into tailings storage facilities (TSFs) at site. Worsley has three active TSFs and from October through to May each year, the embankments of these TSFs are raised at five-meter increments to enable more space for bauxite residue disposal.   

Historically, Worsley has used clay as the primary material for raising TSF embankments. In FY24, after progressing studies and successful trials, Worsley was able to reprocess bauxite residue in its TSFs for use in the construction of their embankments. Bauxite residue constituted approximately 40 per cent of the material used.  

Reprocessing bauxite residue for embankment raising means the residue does not need to be stored in the TSFs, increasing the storage space available. Each cubic metre (about the volume of a large refrigerator) of storage space gained unlocks an estimated A$3 in value and it is estimated that over 3.3 million cubic metres of storage space will be gained over the next ten years.  

Furthermore, Worsley Alumina has a limited on-site supply of clay, which is expected to deplete over the next twenty years. By reprocessing bauxite residue, it is estimated we will reduce our clay usage – a naturally occurring resource - by 1.8 million cubic metres over the next ten years, with potential savings of around A$50 million dollars.