Abstract:Based on Metcal methodology, the process model of zinc oxygen pressure leaching, leachate neutralization and iron removal was established to calculate the whole process material. The results show that when the zinc concentrate input is 25 t/h and the calcined ore addition is 2.69 t/h, the neutralization residue produced is about 1.04 t/h, containing 20.928% Zn, 4.211% Pb and 34.919% Fe. After the neutralization slag returned to the first stage of the reactor, the oxygen required is 3 588.98 m3/h (standard state, the same below), and the oxygen utilization rate of the first stage of oxygen pressure is about 55%. The oxygen required by the second stage oxygen pressure leaching is 2 141.24 m3/h, and the oxygen utilization rate was 26.9%. During the iron removal stage, the oxygen utilization rate drops to 11.8%. A comparative analysis between the model calculations and onsite material assays shows that, the relative deviation of Zn, Pb, S and Fe in the first stage underflow sample is 4.96%, 6.27%, 7.59% and 5.51%, respectively. The relative deviation of Zn, Pb, S and Fe in the second stage underflow samples is 8.75%, 0.73%, 4.70% and 2.48%, respectively. The relative deviations of Zn, Pb and Fe in neutralization slag samples is 3.29%, 9.44% and 6.56%, respectively, indicating that the model has good reliability. The model was used to adjust the return amount of neutralized slag. The results show that the amount of neutralized slag has no effect on the oxygen consumption per unit. However, with the increase of the amount of neutralized slag, the waste acid consumption rises from 4.47 m3/t to 4.61 m3/t, the leaching rate of Zn drops from 80% to 78.19%, and the leaching rate of Fe drops from 15.38% to 14.62%. The return amount of neutralizing slag has influence on zinc leaching rate.