Recovery of Valuable Metals by Leaching of Roasted Jarosite Residue

A new process of roasting ammonium chloride leaching alkali leaching for recovery of valuable metals and iron in jarosite residue generated during zinc hydrometallurgy was studied by experiment.After roasting of jarosite at 650℃ for 1 h,the main phase of KFe3(SO4)2(OH)6 containing Pb and Zn was decomposed into Fe2O3,ZnSO4 and PbSO4.When the roasted jarosite residue was leached by 5 times with aqueous solution of 6 mol/L ammonium chloride at 105℃ for 2 h,over 95% of Zn,Pb and Cd in the jarosite was leached and the iron content was raised from 22% to 40%.The leached residue was further leached with 23.08%(ω) NaOH solution at 160℃ for 1 h,Fe content in the final residue was 54%,which could be used as qualified iron concentrate.