Dissolution behavior of copper concentrate in acidic media using nitrate ions

Abstract

This study was conducted to investigate the dissolution process of copper concentrate using sodium nitrate (NaNO3) in a sulfuric acid (H2SO4) medium under various controlling parameters, including dissolution temperature, time, particle size, solid/liquid (S/L) ratio and concentration of NaNO3 and H2SO4. The thermodynamic probability of mineral dissolution (CuFeS2, Cu2S, CuS, FeS2) reaction in the concentrate was estimated by standard Gibbs energy. The activation energy (Ea) for the dissolution of copper concentrate was calculated as 15.96kJ/mol. Batch experimental results show that about 89.9% of copper in the intact concentrate have been leached and it increased to 96.5% at the fraction with <25.4mm particle size. Copper leaching rate has direct correlation with increase in time, temperature, solid/liquid (S/L) ratio and H2SO4 concentration. The XRD and XRF analyses of the solid residue after leaching revealed the presence of elemental sulfur.DOI: http://doi.dx.org/10.5564/mjc.v15i0.328 Mongolian Journal of Chemistry 15 (41), 2014, p79-84