Surface modification of quartz tailing and its effecton strength and drying shrinkage of cement mortars

The surface of quartz tailing was modified by calcination method through mixing with carbide slag. The mineral composition and microstructure of the modified quartz tailing were analyzed by using X-ray diffraction (XRD), backscattered electron microscopy (BSEM) and energy dispersive spectrometer (EDS). The effects of modified quartz tailing on the drying shrinkage and compressive strength of cement mortars were investigated. The microstructure of cement mortars was analyzed by using BSEM and mercury intrusion porosimetry (MIP). The results show that the β-C₂S phases were formed on the surface of the modified quartz tailings. Due to the hydration of the β-C₂S, CSH gel was generated, the interface between cement paste and quartz tailing was densified, the porosity and drying shrinkage of cement mortars with the modified quartz tailing was decreased, and the compressive strength of cement mortars was increased.