Zinc wire replacement for gold plating
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Hello, friends. I placed zinc wire in a solution containing gold, and the next day the zinc wire was completely gone. The precipitate that remained after filtration was powdered in texture, with a color similar to that of the zinc wire. However, neither hydrochloric acid nor sulfuric acid could dissolve it in large quantities – only a small portion dissolved. My question is: is this because the precipitate is made up of gold? But based on past experience, it should be black. I don’t understand; please give me some guidance. Thank you
Analyze the composition of gold and silver, especially the silver content. In the case of silver displacement, gold-zinc encapsulation is formed, making it difficult to remove zinc. When pickling, pay attention to the acid concentration and temperature.
I haven’t tried removing impurities by heating after adding sulfuric acid yet; I’ll give it a try. There shouldn’t be any silver present – it’s wastewater from gold plating. The gold has already been precipitated once using chemicals, and zinc wire was used for the second precipitation step. Thank you, friend. I would have given you more points, but the highest score I can assign is 3 points; please understand