Influence of ferronickel slag on the reaction kinetics and microstructure of alkali-activated slag

This study aims to investigate the effects of ferronickel slag (FNS) on the hydration heat, mechanical strength and microstructure of alkali-activated slag (AAS). Sodium hydroxide (SH) and sodium silicate (SS) were used as alkali activators to prepare various alkali-activated slag-FNS cements (AASF). The incorporation of FNS has no significant effect on the reaction process of the SH-activated AASF system while delaying the reaction process of the SS-activated AASF system. The influence mechanism of FNS on the reaction process of AASF is unaffected by variations in alkalinity and modulus of the alkali activators. The delay effect of FNS on the SS-activated AASF system is diminished at 60 °C. The reaction degree of FNS at a later age is significantly higher than that at an early age. Mg in FNS participates in the formation of Mg4Al2(OH)14·3H2O and gel products. The reaction degree of FNS increases with the rise of FNS content in the SH-activated AASF system but has no relationship with the FNS content in the SS-activated AASF system.