Effects of Fe and Al ions during hydrogen sulphide (H_2S)-induced corrosion of tetracalcium aluminoferrite (C4AF) and tricalcium aluminate (C_3A)

摘要

With high concentration and toxic H2S gas found in sewage facilities, it has ultra-high leakage risk and great environment impact, once the sealing material failure. In this study, hydrogen sulphide (H2S)-induced corrosion effects of tetracalcium aluminoferrite (C(4)AF) and tricalcium aluminate (C(3)A) phases of cement were evaluated during the initial stages of reaction. Both phase changes and bond structures were examined by techniques including Fourier transform infrared spectroscopy (FTIR). The results indicate that corrosion occurred through a stepwise reaction promoted by Fe ions. The effects of Fe and Al ions were further quantitatively investigated by X-ray photoelectron spectroscopy (XPS) and Al-27 solid-state nuclear magnetic resonance (SSNMR). Compared with hydrated samples, the Fe ions were changed with Fe(II) ions increasing and Fe(III) ions reducing, and the AlOx group was observed to be transformed form AlO4 to AlO6 after H2S corrosion. Changes obtained will be benefit the further development of hazardous H2S control material and risk management operations.