Abstract
Leaching of platinum (Pt) traces from Cobalt-Rich Crust (CRC) in hydrochloric acid (HCl) solution with hydrogen peroxide (H2O2) was carried out in this work. Two kinds of CRC samples with different Pt grades were used and the effects of HCl and H2O2 concentration, leaching temperature and time as well as solid-liquid ratio were investigated to evaluate the Pt leaching.
The results showed that more than 95% of Pt in the CRC sample was leached out in HCl solution which concentration was more than 2 mol/L. The leaching temperature was higher than 50°C and the time was longer than 30 min whereas the solid-liquid ratio was less than 50 g/L. Similar results were observed when using HCl solution of more than 0.5 mol/L with the addition of more than 1 vol.% H2O2, while the leaching temperature was kept at 30°C and the time was longer than 15 min but at a reduced solid-liquid ratio (i.e. less than 10 g/L). There was no difference on Pt leached fraction between the two CRC samples with different Pt grades.
