Bauxite Ore Grade

A measure of the aluminium content in bauxite expressed as percentage of available alumina (Al₂O₃) or total alumina, alongside silica content (particularly reactive silica, SiO₂), iron oxide (Fe₂O₃), and moisture. Grade is the primary economic parameter determining bauxite value and refinery processing cost. High-grade bauxite typically contains above 40% available Al₂O₃ and low reactive silica. Grade control through selective mining and blending is essential to meet refinery specification and optimise economic returns.