Leaching of Nickel from a Jarosite Precipitate with Hydrochloric Acid

Abstract Jarosite precipitates produced at Impala’s Base Metal Refineries contain substantial amounts of nickel. Laboratory-scale experiments were carried out in an attempt to recover nickel by leaching with hydrochloric acid. The leaching efficiency of nickel was 60% at 25oC. The acid concentration of 0.5 – 1 molar, pulp density of 10% and leaching time of 90 min was found to be optimum under the present conditions. High pH could break the jarosite structure and release more iron into the solution which will adversely affect the following precipitation process to recover nickel. 27% of the nickel lost is by entrainment. The reaction is diffusion independent