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 a number of automated valves as shown in the Batch ILR Flowsheet. Each batch of solids is loaded into the drum and the solution containing reagents is recirculated through the drum until leaching is complete. The pregnant solution is clarified and transferred to electrowinning then the solids are emptied by reversing the drum rotation, before the sequence is restarted using concentrate collected while the ILR operation cycle. The Batch ILR is particularly suited to high value concentrates due to the close control that can be exerted over each step of the process minimising the chances of gold loss. For each batch the performance can be closely monitored and measured with load cells and automatic samplers recording all masses and concentrations including, most importantly, the solid tails.
Continuous InLine Leach Reactor
The Continuous ILR is designed for steady operation on a stable feed with dedicated equipment for each duty. The feed is collected and dewatered continuously then flows to the ILR drum together with there circulated barren leach solution. The leached slurry continuously discharges from the tail end of the drum where it is dewatered, using aCCD or filter and the solids discharged. The solution passes to a recovery stage, such as direct electrowinning or absorption, before being recirculated to the feed of the ILR. For each stream the flow rate is controlled and recorded and samples are taken to obtain a full metallurgical balance.
Because the continuous ILR is capable of treating both coarse and fine concentrates it is particularly suited to Gekko GFIL circuits since it means that the gold and silver can be leached at the maximum particle size that results in leach high recovery, minimising grinding costs.
With the Continuous ILR the solid residence time is determined by the size of the ILR, the solid settling characteristics and solids feed rate while the solution residence time, which is usually shorter, is determined by the void age of the solid bed and the flow rate of solution.