ELECTROWINNING
Electrowinning

This is the process whereby metals, such as gold, are recovered from concentrated solutions by applying a voltage across electrodes immersed in the concentrated solution. The voltage applied across the electrodes (cathode and anode) results in a cathodic reaction which in turn results in the deposition of the metal from solution onto the cathode.

The cathode is described as the electrode at which reduction occurs. The negative terminal of the DC supply from the rectiformer is connected to the cathode.

The anode is described as the electrode at which oxidation occurs. The positive terminal of the DC supply from the rectiformer is connected to the anode.

 

Kemix Packed Bed Electrowinning Cell

The recovery of gold from CIP eluate is efficiently achieved by utilising the packed type electrowinning cell. Eluate containing gold and silver generated from either Zadra or AARL type elution are suitable for treatment in the Kemix Packed Bed Electrowinning Cell.

The Kemix Packed Bed Electrowinning Cell is engineered as a non-complex, robust and easy to operate unit having minimal maintenance requirements.

The electrowinning cell consists of a sandwich arrangement of seven anode assemblies on either side of cathode compartments, all contained in a stainless steel tank. The cathodes are constructed from perforated polypropylene or stainless steel baskets filled with mild steel or stainless steel mesh respectively. The anodes are constructed from stainless steel strips. The cathodes and anodes are positioned alternatively within the cell.

The eluate is pumped into the cell at one end and flows through all the electrodes prior to exiting the cell via the overflow weir at the opposite end. Solution bypassing is minimised resulting in the optimisation of pass efficiency.

On completion of the electrowinning cycle the rectifier is switched off. The cathode pin bar and conductor are removed after which the cathodes are manually removed from the cell. These cathodes are washed with high pressure water to recover the metal sludge that has deposited onto the cathode. Once the cathodes have been washed they are returned to the cell and the cathode pin and conductor refitted. The electrowinning process can recommence.

The hinged hood has a locking facility to increase the security associated with the cathode sludge. The hood provides the means for adequate ventilation of the cell by connecting an extraction fan to the ventilation manifold situated at the discharge end of the cell.

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GALLERY
Electrowinning
Electrowinning
Electrowinning
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