Preparation of fly ash-granulated blast furnace slag-carbide slag binder and application in total tailings paste backfill

Based on activation and synergistic effect among various materials, a low-cost mine backfill cementing material, FGC binder, was prepared by using fly ash, granulated blast-furnace slag (GBFS), carbide slag and composite activator. The proper proportioning of FGC binder is obtained by response surface experiment optimization method: fly ash 62 %, GBFS 20 %, carbide slag 8 % and compound activators 10 %. Adjusting the material ratio obtains different cementing material which could satisfy requirements of different mined-out areas. With the mass ratio of cementing material and tailings 1:4~1:8, the concentration of total solid 70 %, the compressive strength values of total tailings filling body at 28 d reaches 1.64~4.14 MPa, and the backfilling cost is 20 % lower than using OPC cement.