Lead Metal Production at Paroo Station Mine Using …
157
Fig. 8 Lead cathode samples from the ALS pilot plant operation
head of the MSA leach circuit to supply iron to leach galena contained in the MSA
leach feed. A small fraction of the thickener underflow is discharged to the flotation
concentrator tailings.
The thickener overflow is treated in a double effect evaporator to recover water as
condensate and maintain the circuit water balance. Evaporator discharge is treated
through two multimedia filters to ensure that no particulates enter the electrowinning
circuit. The solution from these filters (Advance Electrolyte) is delivered to the
electrolyte recirculation tank and subsequently fed to the Electrowinning circuit.
The Advance Electrolyte contains in excess of 300 g/l of lead.
Electrowinning and Cathode Handling
The lead electrowinning circuit is designed to produce up to 80,000 tpa lead
cathode. The tankhouse has 74 production electrowinning cells each fitted with
45 lead cathodes and 46 graphite anodes and operates with a current density of
400 amps/m
2 . The tankhouse has one electrical circuit powered by a 195 V, 34,500 A
transformer-rectifier.