Effective Removal of Barrier Layer on the Surface of Low-Nickel Matte in an FeCl3-HCl-H2O Solution

Abstract

Using ferric chloride as an oxidant, here, we investigated the leaching effect of low-nickel matte in a flow field produced by mechanical agitation. The factors affecting a leaching reaction, such as stirring speed, leaching time, low-nickel matte particle size, and inert abrasive quartz sand, were studied. X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), a laser particle size analyzer, optical microscopy (OM), a scanning electron microscopy (SEM) with an energy dispersive X-ray detector (EDS), and a Raman spectrometer were used to characterize the materials before and after the leaching reaction. The contents of the main metal ions such as Ni, Cu, and Co in the leaching solution were analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). Using the control variable method, the optimal experimental conditions were as follows: 2 mol/L FeCl3—0.5 mol/L HCl-H2O system with low-nickel matte and quartz sand (mass ratio is 1:5) and leaching at 90 °C for 8 h. The results showed that the blocking effect of the solid product sulfur layer was effectively removed and continuous leaching was realized. The leaching efficiencies of Ni, Cu, and Co were 98.9%, 99.3%, and 98.1%, respectively.