Preparation of mine backfilling from steel slag-based non-clinker combined with ultra-fine tailing

This study explores the influence of mechanical activation on the cementitious activity of ultra-fine tailing and the filling performance and hydration mechanisms of a clinker-free backfilling body. A binder with 50% granulated blast furnace slag, 35% steel slag and 15% desulfurisation gypsum, a binder to tailing ratio of 1:4, and a slurry concentration of 78% resulted in strength values of 6.69 MPa, 12.05 MPa, 16.36 MPa and 18.37 MPa after 3, 7, 28 and 180 days, respectively. Ettringite formed during metallurgical slag hydration and C-(A)S-H gels formed by superfine tailings under alkali activation resulted in the high compressive strength.

Automated summary

This study examines the influence of mechanical activation on the cementitious activity of ultra-fine tailings and the filling performance and hydration mechanisms of a clinker-free backfilling body. Through adjusting the ratio and slurry concentration, it is found that the substances formed during the hydration of steel slag and granulated blast furnace slag can enhance the strength of the cementitious body.