Shrinking core model with variable activation energy: a kinetic model of manganiferous ore leaching with sulphuric acid and lactose

A kinetic model of manganiferous ore dissolution varying sulphuric acid and lactose as reducing agent was developed here, The Shrinking Core Model (SC M) was modified to take into account both the variable reagent concentratio ns and the reaction rate change with respect to the manganese dioxide conve rsion: this last aspect is due to several oxidation reactions of the carboh ydrates in a hot sulphuric acid medium. The effects of three factors were i nvestigated for three ore size fractions: temperature, lactose and sulphuri c acid concentrations. The application of the kinetic model to different si ze ore fractions with and without the particle size effect shows that the b est results in data fitting were gained by applying the model separately to each particle size fraction. The influence of the particle size in the kin etic model is discussed with the support of SEM analysis and BET surface me asurements before and after leaching. (C) 2001 Elsevier Science B.V. All ri ghts reserved.