Natural fluorapatite as a raw material for Portland clinker

The present work focuses on the mineralogy and the reactivity of clinkers made from the integration of natural fluorapatite in the raw meals with percentages ranging from 0 up to 15%. The samples were characterized by infrared spectrometry, X-ray diffraction and microscopy techniques. The distribution of phosphorous and fluorine into clinkers minerals was determined by MEB/EDS mapping. The mineralogical composition was determined by XRD/Rietveld and the samples reactivity followed by isothermal microcalorimetry. It has been found that fluorine stabilizes C3S and beta-C2S which still are found with high levels of P2O5. Cements obtained from up to 8% natural fluorapatite incorporation still present acceptable properties. Natural fluorapatite could have an important potential as decarbonised source of CaO contributing to decrease the CO2 emission in cement industry.