Aachen Pre-oxidation to reduce cyanide consumption through oxidation of cyanide consuming species combined with efficient oxygen utilisation. Simple pre-oxidation, designed to oxidise cyanide consumers to prevent excess reagent consumption, may be more efficiently achieved using Aachen reactors where the oxygen mass requirements have been identified as relatively high. Elevated cyanide addition is often an indication for attempted compensation to overcome insufficient leach kinetics due to lack of oxygen at micro level through higher cyanide concentrations.
Aachen Assisted Leach (AAL): As a highly efficient mass transfer device and also a shear reactor Aachen reactors are finding increasing applications within gold and silver leach circuits to accelerate leach kinetics, reduce cyanide consumption and reduce surface passivation. AAL involves the concept of combining oxygen, shear and cyanide to boost the leach kinetics (to increase throughput or reduce tank volume) as a function of drastically reduced film boundary layers, thus enhancing diffusion controlled reactions
Leachox™ involves the oxidative treatment of refractory, sulphidic ores or concentrates with or without UFG (Ultra Fine Grinding) to liberate locked up or at least leach hindered gold. This may involve only particle surface cleaning immediately prior to the leach or actual oxidation of sulphide minerals. At the most severe level, high percentage levels of sulphides will be converted to oxidation products and associated gold made leach amenable.
Tank volume (process dependent)
Minimum residence time during hyper-oxygenation
REA 450 Feed Pump requirement, nominal flow (per unit)
REA 450 Feed Pump requirement, head pressure
m water head
REA 450 Feed Pump installed power
Oxygen delivery, capacity range (per unit)
Aachen unit pressure drop
Oxygen delivery excess head pressure
Interlocks (oxygen pressure and flow) to stop slurry pump
Interlocks (DP slurry to O2 P)
Piping diameter (inlet and exit)
The feed system of each reactor should be equipped with:
Each reactor should be equipped with:
Pumping of slurry without supporting gas flow must be avoided.