HYDROLYSIS-PRECIPITATION STUDIES OF IRON SOLUTIONS .3. APPLICATION OF GROWTH-MODELS TO THE FORMATION OF COLLOIDAL ALPHA-FEOOH FROM ACID-SOLUTIONS

The development of a colloidal αFeOOH phase has been followed experimentally by measuring the dependence of the induction time on the OH Fe ratio and by recording the pH relaxation of samples of known initial OH Fe ratio. These results suggest that the growth of the solid phase is largely controlled by surface-nucleation processes. Two growth models are applied in the analysis of the kinetic data. This analysis permits an estimation of the interfacial tension of the solid to be made in acid solutions. © 1979.