Bauxite silica–aluminium separation inhibitors: a review of mechanisms of action, characteristic types and recent advances

Inhibitors play a crucial role as key reagents in bauxite flotation desilification, significantly enhancing the efficient recovery of alumina. This paper reviews recent research progress on bauxite flotation desilification inhibitors, outlines the global distribution of bauxite resources and systematically categorises commonly used inhibitor types. These primarily include inorganic inhibitors (e.g., sodium hexametaphosphate, water glass), organic inhibitors (e.g., modified starch, polyacrylamide) and novel inhibitors (including synthetic and biogenic inhibitors). The article emphasises the core mechanisms by which these inhibitors selectively suppress silica-bearing gangue minerals through chemical complexation, electrostatic adsorption and targeted binding, thereby enhancing the flotation difference between alumina minerals and siliceous minerals. This review aims to provide theoretical foundations and practical references for further breakthroughs and industrial applications of efficient desilification technologies for low-grade bauxite.