SEM–SCA: combined SEM – Raman spectrometer for analysis of OPC clinker

Obtaining good quality Raman spectra from ordinary Portland cements is not easy, with spectra often being plagued by fluorescence. However, in this paper, the authors present Raman spectra from various points on a cross-sectioned OPC clinker nodule, and show how the different components of the clinker can be readily identified. Samples were analysed using Renishaw's structural and chemical analyser (SCA), a combined scanning electron microscope (SEM) and Raman spectrometer. This technique enables topographical information, elemental composition (from EDS) and chemical information (from Raman spectroscopy) from the same spot without sample transfer. This has allowed the authors to confidently relate the Raman spectra from different points on the surface with elemental composition, therefore identifying the various component mineral phases in the clinker nodule unambiguously. The sample was also analysed by X-ray diffraction (XRD) to confirm phase composition.