Reduction of Amine Consumption in Iron Ore Flotation through Direct Reuse of Process Water on Bench Scale

Abstract

The present work investigated the direct reuse effect of process water containing residual amine from tailings and concentrate pulps on the performance of the cationic reverse flotation of iron ore. Iron ore sample collected after the desliming operation in Conceição Industrial Unit (Minas Gerais) was used for the bench scale flotation studies. The experiments used water recirculation for five cycles and amine to achieve the optimal flotation dosage, considering the residual amine contained in process water and according to the amine dosage used in the Conceição industrial circuit. The average recovery of amine in the aqueous phase (process water) was 46%; consequently, the consumption of the new amine fed into the circuit was reduced. The experiment results showed that the direct reuse of process water and reduction in new amine addition could be performed without negatively affecting the quality of the final iron ore concentrate (68% Fe and 1.3% SiO2). According to the results obtained in this work, process water containing residual amine can be reused in the iron ore flotation without loss of concentrate quality and flotation performance. The chemical composition of the water process is essential, and the residual amine in the aqueous phase must be controlled frequently.