This article develops a versatile structural model specifically suited to describe the dissolution kinetics in leaching processes involving nonporous ore particles. The model accounts explicitly for intraparticle heterogeneity by describing the interplay between the dissolution kinetics of the main solid reactant (e.g. metal oxide) and the dissolution/fragmentation of the solid matrix (gangue). The application to the dissolution of manganiferous ores is thoroughly addressed. (C) 2004 Elsevier Ltd. All rights reserved.