Effect of fluorite tailings on clinker with different chemical modulus: A case study in rotary kiln processing

The rational use of fluorite tailings in cement kilns is an effective method for enhancing their value-added utilization. In this study, the effect of fluorite tailings on the mineral composition of raw meals with different chemical modulus was investigated. It was found that the f-CaO content in clinker increased as the lime saturation ratio (KH), silica modulus (SM) and alumina modulus (IM) of the raw meals rose. The C₃S diffraction peak intensity was observed to weaken with higher IM. Fluorite tailings were shown to have a significant effect on raw meals with high KH and IM values, while their impact on clinker mineral phases with varying SM was comparatively minor. Industrial trials demonstrated that the addition of fluorite tailings enhanced the 28 days clinker strength by 2.3 MPa and reduced f-CaO content by 0.27 %. In addition, the X-ray Photoelectron Spectroscopy (XPS) results confirmed further that F was doping into the clinker mineral phase. The findings of this study strongly support the promotion of fluorite tailings technology to enhance the quality of cement clinker.