Gekko Systems has recently supplied an integrated gravity/leach circuit for the Kencana Project which consists of a new, very high-grade gold and silver underground ore body at the Gosowong mine site on the island of Halmahera, in the eastern part of Indonesia.
Within the ore body a quantity of gravity recoverable gold was identified. It was shown in test work that recovery from this material in the leaching train may not be optimal. A gravity circuit was therefore included in the upgrade of the existing plant.
The Gekko plant includes a Gekko Mag-Screen, Falcon SB1350 and a Gekko Model 1000BA inline leach reactor (ILR).
The Gekko Mag-Screen consists of a permanent magnetic drum and a rotating sieve bend-type screen, all in the one housing. The magnet removes any metallic materials from the feed slurry, while the sieve bend removes material that is too coarse to be fed to the Falcon concentrator. The Falcon upgrades the scalped feed slurry into a concentrate containing several thousand ppm gold and silver and feeds it to the ILR. The ILR leaches a daily batch of around 2.4t of concentrate in a concentrated cyanide solution to recover more than 98% of the gold and silver present.
Up to 27% of daily gold production has been recovered from the gravity circuit to date.