" The bauxite mines in the Darling Range have the world's lowest grade bauxite mined on a commercial scale (around 27-30% Al2O3). Despite the low grade, the mines accounted for 23% of global alumina production as they also have low reactive silica, making the bauxite relatively easy to refine. Bauxite resources also occur in New South Wales (NSW) and Tasmania (Tas) but these are small (<25 Mt)."
Note we have an average silica content of 6.8 ranging from 1.8 to 10%. It is my understanding anything below 10 is ideal meaning lower temperature furnaces required. ie lower reactive silica.
