Experimental and kinetic study of zinc leaching from metallurgical slag by 5-sulfosalicylic acid
Long Wang, Hanyu Gao, Shimin Song, Na Xue, Jinxia Zhang, Siyuan Yang, Cheng Liu
Abstract
As an organic acid with the characters of low corrosivity and extensive source, 5-sulfosalicylic acid (5-SSA) was firstly utilized as a potential leaching reagent for the recovery of zinc from metallurgical slag. Effects of stirring speed, leaching temperature, 5-SSA concentrations and size fraction on the leaching zinc leaching rate were investigated. A zinc leaching efficiency of 94.2% was achieved under the appropriate operating conditions (450 rpm of stirring speed, 50 of leaching temperature, 0.3 mol/L of 5-SSA concentration and d90=65 m of size fraction), indicating that 5-SSA was an excellent leaching reagent of zinc oxide. SEM-EDS and specific surface aperture analyzer further reveal the well-developed micropores and cracks from zinc metallurgical slag, which could be assigned to the removal of zinc oxide encapsulated in the sample. In addition, the leaching kinetics of zinc metallurgical slag in the 5-SSA was studied. It was found that the surface chemical reaction model satisfactorily predicted the zinc leaching rate. A reaction kinetic equation was finally established for the zinc leaching rate.