Influence of particle size on the reactivity of chemical modified steel slag powder

Abstract

Understanding how the particle size of steel slag powder (SS) affects modified efficiency via chemical modified approach is critical to improve the modification process and the utilization of SS as sustainable cement-based materials. By using quantitative analysis based on backscattered electron images, the quantitative mineral compositions of SS with varying particle size (0–38, 38–75, 75–150, 150 μm) at micro-scale are obtained. Results show that the active mineral content decreases from 68% to 61% with steel slag particle size increases from 0–38 to 150 μm. Such composition divergence is one of the factors resulting in a significant difference on the 72 h cumulative hydration heat and 3 d compressive strength performances of the steel slag pastes. Combine the cumulative hydration heat values with the compressive strength results, the steel slag with particle size smaller than 75 μm is advised as the optimum section for chemical modification.

Keywords:

• Steel slag powder
• formic acid
• modification
• particle size
• reactivity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors would like to thank the National Natural Science Foundation of China (Nos. 51778132, 51972057) for its support.