Recycling and comprehensive utilization of ferronickel slag in concrete

Ferronickel slag (FNS) is a solid waste produced in the smelting of ferronickel alloys. FNS is classified as blast furnace ferronickel slag (BFS) and electric furnace ferronickel slag (EFS). They are useful in many fields, such as metal recovery and glass manufacturing. In fact, replacing cement or concrete aggregate is the best way to achieve large-scale resource recycling of FNS, while generating environmental and economic benefits, which is consistent with the concept of sustainable development. This paper summarizes the research papers of FNS as supplementary cementitious materials (SCMs), aggregates and precursors and comprehensively analyses of the sustainable utilization of FNS. The results suggest that BFS is suitable for use as SCMs with small replacement and relatively high activity, but it needs to be ground to 400–500 m2/kg. EFS is suitable for use as aggregate due to its high discharge and strong interlocking ability of particles. The influence of FNS on the performance of geopolymer concrete is mainly related to the types of precursor and activator. Combined with the results of this paper, the research direction of further improving the recycling efficiency and cleaner production of FNS is given.