Direct use of original granular steel slag to prepare multi-phased clinker: Sintering mechanism and properties

Multi-phased sintering technology is an innovative process that directly utilize granular steel slag to calcinate cement clinker. In this study, we synthesized a type of multi-phased clinker with high fractions of original crude granular steel slag and investigated its sintering mechanism and properties. It is found that the diffusion of the molten liquid phase of granular steel slag to the surrounding area influenced the crystallization and growth of the clinker mineral, consequently, a gradient distribution high-ferrite multi-phased clinker was formed. Steel slag changed the clinker mineralogical composition and resulted in the ferrite phase reaching 18.07–28.09%. Laboratory tests showed that the multi-phased clinker with high content of steel slag was technically viable and still obtained exceptional properties. The grindability and soundness of multi-phased clinker were comparable to the ordinary Portland clinker, and the burnability was considerably higher than conventional raw meal. All of which suggested that this process was robust and provided more comprehensive theoretical basis for the industrial application.