In the process for electrolysis for zinc, three things must be done:
- Leaching the ZnO
- Purifying the ZnSO4 by means of cementation
- Performing the electrolysis
However, step 2, as it is presented by Wikipedia, is quite vague. In particular, it says:
The purification process utilizes the cementation process to further purify the zinc. It uses zinc dust and steam to remove copper, cadmium, cobalt, and nickel, which would interfere with the electrolysis process.
However, when looking it the definition of cementation, a crude summary of what happens is that one metal gets oxidized in order to reduce the other ion. I am assuming that this means that the zinc sulfate is getting reduced. However, what is reducing it? What equations are involved? I apologize if this question does not make sense, as chemistry is not particularly my strong suit, but I believe that this has gone unanswered online so far.