How is alumina refined?
The high temperature tube digestion Bayer Process will be used at the refinery at Abbot Point. The process includes: 1. Bauxite is delivered to Abbot Point by ship. 2. A conveyor will transport the bauxite to the alumina refinery. 3. The bauxite is crushed and dissolved in caustic soda and digested at temperature and pressure to produce a solution, known as process liquor. 4. The mud and sand is separated from the process liquor in washer and thickening plants through a clarification process. 5.a) The clarified solution is precipitated to produce aluminium hydroxide, commonly referred to as hydrate. 5.b) The mud and sand (bauxite residue) is neutralised several times using seawater. The majority of the water is removed from the residue and recycled in the alumina refinery. The bauxite residue, which remains in a moist condition, is stored in the Residue Storage Facility (RSF) where it dries out over time. 6. Calcining of the hydrate occurs in temperatures of around 1000C to produce alu
