Laboratory batch leaching tests were conducted on two historical South Australian copper ores. The dominant copper mineral in each ore was malachite, and sulphuric acid was used as the leachant. The leaching kinetics of the Burra copper ore could easily be modelled by a simple first order rate equation, but the leaching kinetics for the Kanmantoo copper ore required a more complex model, similar to that proposed by the first author for the leaching of copper from atacamite in the Mount Gunson copper deposit. Using the current model it was possible to predict the ultimate copper extraction and the two rate constants operating for leaching the Kanmantoo copper ore. It was also possible to predict the optimum particle size beyond which increasing the fineness of grind had little effect on copper leaching rate or extent.