Research progress on volume expansion and stabilization treatment of steel slag

ZHAI Chaowei; WAN Chenguang; WANG Xiaofeng

doi:10.3969/j.issn.1001-702X.2026.02.005

Abstract：The causes and influencing factors of the volume expansion of steel slag were analyzed,and the methods for stabi-lizing the volume expansion of steel slag were summarized.The research progress and characteristics of different treatment methods were discussed,and future directions and suggestions for further exploration were proposed.The research results indicate that free calcium oxide(f-CaO)and free magnesium oxide(f-MgO)in steel slag are the main causes of the volume expansion of steel slag;The process,melting and tempering,and aging treatment can significantly reduce the content of active substances in steel slag,with a reduction rate of up to 60%to 90%.Carbonization treatment,acidification treatment,and the addition of mineral materials can ef-fectively eliminate active substances such as f-CaO in steel slag,and the reduction rate of volume expansion of processed steel slag can reach over 80%;The surface modification treatment method is simple and has a short cycle,but the treatment effect is rela-tively weak,and there is still a risk of modifier detachment in the later stage,causing the volume expansion of steel slag;Long term monitoring of various properties of processed steel slag mixture,development of unified comprehensive treatment technology for steel slag volume stabilization,and strengthening the uniformity of carbonization inside and outside steel slag aggregates can be used as future research directions for steel slag volume stabilization treatment.