Copper Electrolyte Purification

During the copper refining process, impurities in the anode dissolve into the electrolyte or form anode slimes. When arsenic, antimony and bismuth enter the electrolyte, they can undergo a number of different reactions depending on their concentrations, as well as the presence and the concentration of other elements. Arsenic enters the electrolyte as As(III), and is gradually oxidized to As(V). Under these circumstances, insoluble antimony and bismuth arsenates are formed causing issues with the tank house circulation of both pipe work fouling and copper cathode nodulation. In the past refineries have undertaken multi-step purification processes to tackle the impurity build-up including different ion exchange techniques. Unfortunately issues of resin poisoning and usage of high regeneration acid have made these processes both expensive and difficult to operate.

Belmar has addressed the issue of resin poisoning and fresh regeneration acid usage, finally offering copper refineries a viable technology, which removes antimony and bismuth from their copper electrolytes.

Belmar works only with Lewatit resins.

The recycling of the eluent is a crucial step towards making the whole process economically efficient and through the Belmar process, 80% of the eluent acid is recycled.

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The Belmar Process

The Belmar ion exchange process selectively removes Antimony (Sb) and Bismuth (Bi) in a fully automated process parallel to the tank house operation, all operations are interlocked with the added security of an online chloride monitor that checks the quality of the electrolyte before it is recycled back to the refinery process.

The electrolyte is pumped through the ion exchange resin bed unit.  Sb and Bi are removed by the resin beads and the remaining almost Sb/Bi free copper electrolyte is returned to the tank house.

Special Regeneration Prolongs Resin Life

When the resin bed has become fully loaded with Sb and Bi a special regeneration process using hydrochloric acid. This process typically takes around 3 hours and the Sb and Bi contamination which is removed is converted to a concentrated Sb/Bi chloride salt solution.

The special regeneration sequence which Belmar has developed prevents resin poisoning by ferric ions.  The resin will retain its high capacity for Sb and Bi providing a long service life.

The Belmar system which has a modular design enables our copper refinery clients to process copper concentrates with high Sb and Bi concentrations.

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Pilot Trials

Belmar offers site based trial programs to demonstrate our process.  Please contact us to discuss your specific requirements on +44 (0) 1327 586008 or email

Belmar Technologies was part of the team at the Atlantic Copper Refinery in Huelva, Spain which carried out extensive pilot work on the removal of Antimony and Bismuth from their electrolyte. You can download a copy of the Technical Paper detailing the Test results below: