Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

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Adhered Bubbles on Copper Deposit (1 reply and 1 comment)

A
Cl.BrINHOF
5 years ago
Cl.BrINHOF 5 years ago

While electrorefining in a CuSO4 electrolyte (Cu anode to SS blank) what are the roles of additives (thiourea, glue, salt) in relation to bubble formation? More specifically, is there any evidence to support the claim that the potential to create more stable bubbles is increased with higher reagent dosing?

In a case where resilient bubbles adhere to cathodes, leave holes in deposits, and pump cavitation is unlikely, are the adhered cathodic bubbles more likely to be:

1. Air in electrolyte?

2. O2 from secondary anode reaction? 

3. H2 from secondary cathode reaction?

 

I
ismramirez
5 years ago
ismramirez 5 years ago

Hello, I used to work at a large copper electrorefining plant for over 16 years. Based on my experience, under normal reagent dosages, there should not be a big effect on bubble formation. However, abnormally high concentration of glue increase the cell voltage which can lead to bubble formation in the anode (a cause of anode passivation). 

However, the main cause of holes in copper deposit is air in electrolyte. This can be avoided by using a properly designed head tank and opening purge valves in electrolyte pipes through out the whole system. A cell cannot be energized before the air has been vented out the electrolyte. To check this, you can look at the electrolye surface in the cell, there should not be visible small bubbles. 

Once all the air has been purged, the cell can be energized and if bubble formation occurs, then you should check cell voltage and glue addition.

Hope these comments are useful for you.

Sincerely,

 

Ismael Ramirez

A
Cl.BrINHOF
5 years ago

Thank you. I appreciate your response.

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