Rotating disc dissolution rates of ionic solids. Part 3.—Natural and synthetic ilmenite

Abstract

The dissolution rates of rotating discs of polycrystalline synthetic ilmenite (FeTiO₃) and a natural ilmenite mineral in sulphuric acid (4.7 to 12.5 mol dm^–3) over the temperature range 65 to 85°C were independent of the hydrodynamic conditions and had apparent activation energies of the order of 90 ± 10 kJ mol^–1, indicating that the reactions were controlled by chemical processes at the mineral surface. The behaviour of the single crystal natural ilmenite disc indicated the importance in the dissolution process of twinning planes and of altered surface regions and provided information on natural weathering processes.