Earlier investigations have shown that the dissolution of moderately sintered haematite: in a reductive-complexing formulation containing citric acid, EDTA and ascorbic acid (CEA) in the initial concentration ratio of 11:44:4 mol m(-3) at pH 2.8 is faster than at other concentration ratios when the amount of haematite initially taken corresponded to 22 mol m(-3) iron. The dissolution was considered for a system having a surface area to volume ratio of 67 m(-1) with oxide thickness of 5 microns, a system volume of similar to 6 m(3) and no regeneration of chelant. In the present work, the dissolution behaviour of iron oxides prepared from ferrous hydroxide heated at different temperatures ranging from 373-1073 K in CEA 11:44:4 mol m(-3) was investigated. It was observed that the dissolution of samples prepared at lower temperatures was fast, analogous to the behaviour of haematite sols. The results have been interpreted on the basis of ＇Grain model＇.