Liberator circuits are critical in copper refineries to control copper and impurity levels in the electrolyte. Often these circuits are plagued with inefficiencies such as poor quality of copper cathode, large copper recycles, acid mist, hazardous arsine generation, low-grade copper sludge and so on.
The most advanced liberators for copper refineries are emew electrowinning cells. The unique cell design delivers high-grade saleable cathode (even from secondary liberators) improved current and energy efficiency, improved copper and impurity control over a range of concentrations, recycling of acid and reduction in effluents.
The health and safety benefits with emew electrowinning cells for copper liberators are second to none with no handling of hazardous sludge, no risk of arsine exposure, no acid mist, no lead anodes and solid cathodes that are safe to handle.
Converting existing liberator cells to refining cells can further increase production that in itself can pay off the investment for the upgrade to emew. Additional value can be gained by using emew to electrowin nickel as cathode from the de-copperized effluent.
For refineries operating with high bismuth and antimony tenors, emew also offers resin technology to recover bismuth and antimony from copper refinery bleed streams. The removal of bismuth and antimony prior to the liberator circuit allows the emew liberator cells to operate at higher capacity without compromising the purity of the copper cathode product.
Acid Purification Units (or APU) are also available which enable the acid to be recovered from the copper depleted bleed stream and recycled to the copper electrorefinery. Installation of an APU post copper liberator results in significant additional cost savings due to reduced acid consumption in the refinery and reduced neutralization requirements for treating the de-copperized bleed. Furthermore, nickel metal can also be recovered from the de-copperized, de-acidified bleed stream.
The commercially proven emew nickel process also enables high purity nickel cathode to be recovered directly from copper refinery bleed streams. This unique process recovers high purity nickel without complex diaphragms that are necessary with conventional electrowinning.
The choice is clear, the most advanced liberators for copper refineries have emew inside.