Reduction of Ferric Ion from Zinc Hydrometallurgy Acid-Leaching Solution Using Zinc Sulfide Concentrate

In response to the problem of additive zinc concentrate consumption and inefficient reduction of ferric ion (Fe³⁺) in the acid-leaching solution of zinc hydrometallurgy when employing zinc sulfide concentrate, various parameters were examined. These included particle size, temperature, addition coefficient of the concentrate, and sulfuric acid concentration, all aimed at enhancing the rate of Fe³⁺ reduction. The results indicated that increasing the temperature from 80 to 120°C enhanced the Fe³⁺ reduction rate from 93.3 to 98%, reducing the time from 180 to 60 min. Furthermore, enlarging the particle size of the concentrate from below − 58/+ 48 μm to − 246/+ 150 μm, lowering the Fe³⁺ concentration in the reduction solution to < 0.5 g/L, and decreasing the addition coefficient from 1.8 to 1.5 further enhanced the reduction process. Additionally, employing a pressure process to increase the reduction temperature proved to be an effective strategy for enhancing the utilization rate of the zinc sulfide concentrates and the Fe³⁺ reduction rate, thereby reducing the amount of reduction residue and facilitating its subsequent treatment.