APLICAÇÃO DO MODELO DO NÚCLEO NÃO REAGIDO À LIXIVIAÇÃO DA CALCOPIRITA PELO ÍON Fe

Chalcopyrite leaching by ferric iron is considered a slow process with low copper recovery; a phenomenon ascribed\udto the passivation of the mineral surface during leaching. Thus, the current study investigated the leaching kinetics of a\udhigh purity chalcopyrite sample in the presence of ferric sulfate as oxidant. The effects of the stirring rate, temperature,\udEh and Fe3+ concentration on copper extraction were assessed. The leaching data could be described by the shirking\udcore model (SCM) for particles of unchanging size and indicated diffusion in the ash layer as the rate-controlling step with\uda high activation energy (103.9±6.5kJ/mol); likely an outcome of neglecting the effect of particle size distribution (PSD)\udon the kinetics equations. Both the application of the quasi-steady-state assumption to solid-liquid systems and the effect\udof the particle size distribution on the interpretation of kinetics data are also discussed