Batch InLine Leach Reactor
Initially designed to handle coarse concentrates from batch centrifugal concentrators, such as the Falcon, Knelson and InLine Spinner, the flexible, robust design is now used to successfully leach smaller volumes of even the finest gravity and flotation concentrates. The well mixed horizontal drum design gives the ILR the flexibility to handle any leaching chemistry and reagent regime.
The Batch ILR design utilises the simplest possible mechanical system with one rotating drum, two conical storage tanks, a pump sump and anumber of automated valves as shown in the Batch ILR Flowsheet. Eachbatch of solids is loaded into the drum and the solution containing reagentsis recirculated through the drum until leaching is complete. The pregnantsolution is clarified and transferred to electrowinning then the solids areemptied by reversing the drum rotation, before the sequence is restartedusing concentrate collected while the ILR operation cycle. The Batch ILRis particularly suited to high value concentrates due to the close controlthat can be exerted over each step of the process minimising the chancesof gold loss. For each batch the performance can be closely monitoredand measured with load cells and automatic samplers recording all massesand concentrations including, most importantly, the solid tails.
Continuous InLine Leach Reactor
The Continuous ILR is designed for steady operation on a stable feedwith dedicated equipment for each duty. The feed is collected anddewatered continuously then flows to the ILR drum together with therecirculated barren leach solution. The leached slurry continuouslydischarges from the tail end of the drum where it is dewatered, using aCCD or filter and the solids discharged. The solution passes to arecovery stage, such as direct electrowinning or absorption, beforebeing recirculated to the feed of the ILR. For each stream the flowrateis controlled and recorded and samples are taken to obtain a fullmetallurgical balance.
Because the continuous ILR is capable of treating both coarse andfine concentrates it is particularly suited to Gekko GFIL circuits since itmeans that the gold and silver can be leached at the maximumparticle size that results in leach high recovery, minimising grindingcosts.
With the Continuous ILR the solid residence time is determined by thesize of the ILR, the solid settling characteristics and solids feed rate while the solution residence time, which is usually shorter, is determinedby the voidage of the solid bed and the flow rate of solution.