An overview of the beneficiation of iron ores via reverse cationic flotation

• The main routes of iron ore flotation were reviewed.
• Reverse cationic flotation is the most used flotation method of iron ore beneficiation.
• Ether amines and starches are usually used as collectors and depressant, respectively.
• Selective depressants for Fe-bearing silicates deserve further investigations.

Flotation is the most effective solution, both technologically and economically, when upgrading iron concentrates. Research regarding iron ore flotation began in 1931, demonstrating that reverse cationic flotation is a very efficient method for beneficiating oxidised iron ores. This method can also be applied to reduce the silica content in magnetite concentrates obtained using wet low-intensity magnetic separation. Several studies describing the processing of iron ores via reverse cationic flotation are reviewed. The predominate role of the pulp mineralogy, as well as the type and molecular structures of the collectors and depressants, on flotation is discussed critically. The results concerning the role of the silicate mineralogy on the choice of reagents and flotation processes are also discussed. Further development of the reverse cationic flotation of iron ores requires a more detailed consideration of the nature of iron-bearing gangue minerals and the application of original approaches for the selective removal of these species.