Influence of alumina modulus on formation of high-magnesium clinker and morphological evolution of MgO

Abstract

This work investigates the influence of alumina modulus (AM) on the formation of high-magnesium clinker (w(MgO) > 5 %) and the morphological evolution of MgO and prepares clinkers with different MgO contents by using analytical reagents. High-temperature microscopy (HTM), thermogravimetric–differential thermal analysis (TG–DTA), X–ray diffraction (XRD), optical microscopy and backscattered electrons–energy–dispersive spectrometry (BSE–EDS) examine the clinkering mechanism. The results show that a reduced AM improves burnability of raw meal and the formation of more regular and larger alite particles. An increased AM contributes to reducing the size of the periclase and causes the shape of its particles to be round. An AM of 1.1 leads to the lowest liquidus temperature and increased tricalcium silicate (C3S) content. In this case, a maximal solid solubility and a minimal crystallinity of MgO can be obtained. The highest content of C3S and tetra-calcium aluminoferrite (C4AF) can be achieved at an MgO content of 3 %–6 %.