Hall–Héroult process
1.9-3.6 tons of bauxite is required to produce 1 ton of aluminum oxide. This is due to a majority of the aluminum in the ore being dissolved in the process. Energy consumption is between 7 GJ/tonne to 21 GJ/tonne (depending on process), of which most is thermal energy. Over 90% (95-96%) of the aluminium oxide produced is used in the Hall–Héroult process to produce aluminium.