A study on leaching kinetics of chalcopyrite in KNO3 + H2SO4 medium

This paper describes the leaching behaviour and dissolution kinetics of chalcopyrite wıth potassium nitrate in sulphuric acid solutions. Reaction temperature, solid/liquid ratio, stirring speed, chalcopyrite particle size, concentration of sulphuric acid and concentration of potassium nitrate solutions were selected as process parameters. The experimental results were successfully correlated with linear regression using the Statistical package program and dissolution curves were evaluated by the shrinking core models for solid-fluid systems. Finally, it was found that increasing reaction temperature and decreasing solid/liquid ratio caused an increase in the dissolution rate of chalcopyrite. The dissolution extent slightly increased with the increase in the stirring speed rate between 300-900 rpm under the experimental conditions. The activation energy was found as 78.25 kJ mol-1. It was seen that the leaching of chalcopyrite was controlled by surface chemical reactions.