the loaded truck then is trammed to a sump area near the backfill site where the load is deposited.next,a wagner ST-8B,caterpillar 980C,or MTI 700M loader mixes the rock and slurry in the sump. Once mixing is complete,the loader then transports the material into the area to be backfil and places it in a 1-m life. this sequence of lifts conntinoues to 3.5 m from the back.at this time,a JCI 400M loader mounted with a 5-m-long boom with a 30-by 90-cm pusher blade at the end pushes additional -1-m rock to within 0.5 to 1m of the back,creating a bench that is 1 to 2.5m deep