Semi-continuous froth discharge to reduce entrainment of fine particles in flotation cells subject to low-mineralized froths

An operational strategy is proposed to improve the metallurgical performance of flotation cells subject to low-mineralized froths. This strategy consists of using a semi-continuous discharge into the concentrate, in which the froth is operated under loading and unloading periods. A transient model is developed to evaluate the proposed approach. The model is calibrated using experimental data from two industrial flotation banks. The metallurgical performances of the last cells of these banks are then simulated, considering the semi-continuous froth discharge. The results show that the semi-continuous mode significantly reduces gangue entrainment, improving the concentrate grade while maintaining approximately the same recovery. The semi-continuous strategy demonstrates good potential to enhance the metallurgical indexes under low-mineralized froths, as those in the last cells of rougher flotation banks