Experimental study on the ratio between ti-bearing blast furnace slag-iron-based full tailing sand and cement in cementitious filling

Abstract

This study investigated the optimal ratio and mechanical properties of iron-based full tailing sand(IFT)and cement(P.O42.5R)as experimental materials, with the addition of the Ti-bearing Blast Furnace Slag(TBS), in full tailing sand cemented filling material. The physical and chemical properties of TBS, including particle size gradation composition and chemical composition, were analyzed. Filling specimens were prepared with sand-cement ratios of 1∶4, 1∶6, and 1∶8, and TBS replacement ratios of 40%, 50%, 60%, 70%, and 80%. The uniaxial compressive strength of the filling specimens was measured after curing for 7, 14, and 28 days. The experimental results demonstrated a positive correlation between the compressive strength of the filling and the curing time. Additionally, under the same curing time, the uniaxial compressive strength of the filling increased with the increase of the sand-cement ratio. With an increase in the replacement percentage of TBS, the strength of the filling initially increased and then decreased at 28 days. Notably, when the TBS replacement ratio was 50%, the compressive strength of the filling with ratios of 1∶8, 1∶6, and 1∶4 after 28 days of curing was 1.8 MPa, 2.5 MPa, and 4.0 MPa, respectively. All of these values exceeded the strength of the specimens without TBS, indicating that the addition of TBS significantly improved the compressive strength of the filling at 28 days. The research results demonstrate that TBS can be developed as a cementitious material for mine backfill, thereby reducing the cost of mine filling.

Keywords

• filling ratio
• ti-bearing blast furnace slag
• tailing cementation
• solid waste utilization
• cementitious materials