Ammonia process electrowinning of zinc
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Good news! Breakthroughs have been achieved in the purification of electrowinning zinc using the ammonia method, especially in lead removal technology!
First of all, congratulations! Please share the details. Removing lead in the ammonia-based electrowinning zinc process isn’t a difficult task; it just depends on whether that method is cost-effective and has a simple process.
It is difficult to remove lead from solutions with high lead content to levels below 0.3 mg/L under high-chloride conditions!
Indeed, it is somewhat difficult to remove lead to that level using zinc powder directly, but there are other methods. According to the process used by our company for producing 6N zinc, we require that 12 types of metal impurities, including lead, be reduced to levels below 0.01 mg/L, though this is indeed quite challenging.
To meet the requirements of qualified ammonia-based electrozinc baths, electrolytic lead is also an option. But from the perspective of investment and costs, it’s not very cost-effective!
For electrozinc produced by the ammonia method, what is the upper limit for metal impurities?