A New index and control method of filling effect for cemented paste backfill in coal mines

The scientific filling effect characterization is very important for backfill mining. A new filling effect index, the final backfill ratio (FBR), is proposed through experimental tests and theoretical analysis, and the sensitivity of FBR is studied in this paper. The control method of FBR is obtained and applied to optimise the filling effect for the backfill panel in Kailuan Group in China. It is concluded that every 0.05 m reduction of the void between the filling body and roof corresponds to 1.87% increase in FBR. FBR increases by 1.47% and 3.15% respectively when the UCS of the backfill body increases from 2MPa to 3MPa and 4MPa.

Automated summary

A new filling effect index, FBR, is proposed in this study through experimental tests and theoretical analysis. The sensitivity of FBR is investigated and the control method of FBR is obtained. The results show that reducing the void between the filling body and roof and increasing the UCS of the backfill body both can significantly increase the FBR.