the first backfill plant at the Buick Mine went into operation in 1993. The plant is composed of an 8—m3 Denver mixer fed by two Conveyor belts, one of which feeds cement and fly ash from two 63-tonne bins and the other which feeds cycloned railings from a storage hopper [Figure 5.21. Cement and fly ash are delivered to the underground bins from surface via a 20-cm-in-diameter,305-m—deep cased hole. Cycloned tailing: (Table 8.1) are
dropped from the surface down another 20—cm—in— diameter hole
and deposited in a sump area, where the water is decanted. Once
the cycloned railings are allowed to dry, they are picked up by a
Caterpillar 966 loader and fed into the tailings hopper. The mixer
is capable of cycling a hatch of slurry in 7 min. For normal back-
filling, the slurry batch mix consists oi the following materials.