Simultaneous Pressure Oxidation Leaching of Zinc Sulfide Concentrate and Neutral Leaching Residue

Lab-scale simultaneous leaching of zinc sulfide concentrate and neutral leaching residue obtained by traditional roast-leach-electrowin(RLE) were performed in various conditions to investigate leaching variables such as leaching temperature,leaching duration,oxygen partial pressure and stirring rate.Experiments were carried out in a 2-liter autoclave.Experimental results show that zinc sulfide concentrate and the neutral leaching residue help each other to leach in such simultaneous leaching experiments,but the coupling effect occurs obviously only in a given leaching conditions.In this work some mechanisms are proved in the experiments.For the sake of subsequent scale-up experiment,the reasonable condition of simultaneous leaching is given as follows.leaching temperature,135℃;leaching duration,2hr;oxygen partial pressure,0.8 MPa;initial acidity,120g/l.