Copper recovery. Millingagglomeration circuits, Rahco leachdump stackers, SX/EW plants. Expand . A PH 2800 mining shovel loading a 973 hauler. Hauling waste rock to backfill the workedout pit requires a big truck fleet. One of Morenci's 797,272t (300st) capacity mechanicaldrive haul trucks. Lowgrade ore is ballmilled before being agglomerated .