Kinetic study of Fe silicates formation during iron corrosion in deaerated and alkaline Si-containing solutions at 50 °C

Kinetics of Fe silicates formation during iron corrosion in deaerated Si-containing solutions (Si concentrations varying from ≈0 to ≈110 mg L−1) were investigated for pH ranging from 7.5 to 10.1 at 50 °C. All Si consumption curves showed an induction period characteristic of nucleation and growth processes involved in Fe silicate formation. The experimental data obtained at pH≈ 7.5 and pH≈ 8.1 were correctly reproduced with a simplified model considering only the growth mechanism from dissolved species. This model however failed to reproduce the results obtained at pH≈ 10.1. Improving the description of nucleation processes seems necessary to achieve a more predictive modelling.