Goldfinger4 wrote:Still waiting for your report
I am also currently experimenting around with a sulfuric acid cell. I use plated spoons, 37% sulfuric acid and a stainless steel electrode.
Up to now is did nor notice any AgSO4 crystals at the bottom of the container. I don't understand why this should happen - silver permanently dissolves at the steel electrode.
When I used 37% sulfuric acid, the silver went into the solution. I would see it immediately. I was using a 12v@80A. The cell ran a constant ~50A. The cathode was lead. The copper was plating out to the cathode. It would take 10 minutes to deplate a bowl. After about an hour or so it would seem to stop working. The electrolyte was full. I cemented out the silver with a copper bar. I was able to start up the cell after that, but it wouldn't work as well. This is when GSP told me I would have problems trying this way. Since then I have been getting supplies together to doing right.
I also tried to melt the silver of from plated brass. The melting temperature of brass is above 1000°C. With a temperature of 985°C all silver flows to the bottom of the melting pot. This is clearly visible as the brass is covered by red copper oxide. Be careful not to inhale zinc fumes.
The purity of the silver is about 40-50%, mainly polluted by zinc and brass material because the furnace is always hotter at the bottom and there some brass will be melted. I let the spoons in the pot for around 15 min. Maybe less than 15 min would be possible. My furnace runs on 700W.
How clean is the brass when it comes out? Is it clean enough to sell as brass? The few pieces of brass plated silver was yellow brass, and there is some other white metal on it. It couldn't be sold sold as brass.
With some finagling, I got the copper pieces are clean enough to sell as #1 copper. It is not practical to do on a larger scale. There is too much labor involved.