Extraction of tricalcium aluminate for research applications by selective dissolution of portland cement clinker

Tricalcium aluminate (C3A) is the most reactive phase in portland cement clinker. In the study of the C3A hydration process, the use of synthetic samples is often preferred over clinker-sourced samples due to the absence of traces of other elements in synthetic C3A. However, the reproduction of results from synthetic samples using clinker-sourced C3A samples is challenging due to the difficulty of complete extraction of aluminate phases from clinkers without damaging their structure. Salicylic and maleic acid/methanol solutions were used in the past to isolate C3A, but complete extraction has not been observed. Thus, it was necessary to modify the selective dissolution (SD) method. Possible processes were tested with white and ordinary portland clinkers. A modified process with maleic acid/methanol solution was developed and the samples were analyzed by X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Raman spectroscopy, compared with synthetic C3A samples. The modified selective dissolution process with maleic acid/methanol solution proposed in this work was effective in achieving complete isolation of aluminate-based phases, and can be used for further studies of the hydration process of clinker-sourced C3A samples to improve the understanding and quality of portland cement clinkers.