Process water reuse in iron ore flotation: Reducing amine consumption

This study aimed to evaluate the reuse of process water through the immediate recirculation of water from reverse cationic flotation of iron ore in subsequent flotation cycles, focusing on reducing water and ether-amine consumption. Bench-scale flotation tests were conducted in rougher and cleaner stages using water from three different streams of an iron ore beneficiation plant located in Brazil. The recirculation of water containing ether-amines, originating from the concentrate and flotation stages, allowed for a gradual reduction of ether-amine dosage per cycle, totaling more than 15% savings over five cycles, without compromising mass and metallurgical recovery. The concentrates achieved iron grades above 67% and SiO2 levels below 2.6%, regardless of the water source used. Therefore, the results demonstrate technical feasibility at laboratory scale (technology readiness level 4) for saving water and ether-amines in the process, with potential for industrial-scale application.