Industrial test and application of new binder filling in a mine in Lhasa

The new binder has significant advantages in solving the problems of long setting time of filling slurry and poor performance of backfill. In this paper, the filling quality of cemented fine tailings with new binder is systematically evaluated by continuous shift sampling at the filling station to detect the concentration of tailing mortar, filling slurry, cement sand ratio and strength of the backfill, and compared with the cement filling quality. Finally, the cementation mechanism of the two materials is preliminarily analyzed by scanning electron microscope. The results show that the fluctuation range of measured and monitored values of tailing mortar and filling concentration in the filling industrial test is small, the deviation between the instrument monitoring value and the measured value is small, and the filling concentration of cement and new binder is between 55.57% and 57.61%; The new cemented material can significantly improve the strength of fine tailings backfill. The filling concentration of the new cemented material is 55.57%, and the sand cement ratio is 8.8. The strength of the backfill after 7 days, 28 days and 60 days of curing is 4.9 higher than that of the sand cement ratio, and the cement backfill is increased by 40.53%, 118.09% and 85.58%. The results show that the filling concentration is 56.04%, the sand cement ratio is 12.7, and the strength of the backfill cured for 7 days, 28 days, and 60 days is 8.8 higher than that of the sand cement ratio, respectively. The cement backfill increases by 142.11%, 110.29%, and 114.19%. Scanning electron microscope shows that the new cemented material backfill is mainly composed of needle like ettringite and other hydration products, and the overall structure is dense. The corresponding cement backfill is mainly composed of burr like hydrated calcium silicate gel, with loose structure.