PbSnAg and PbInAg alloys to process.

Hello,

I have around 2,5 kg of Lead Tin Silver and Lead Indium Silver alloys in the form of very small squares (5x5x0.2mm). 92.5% of Lead 2.5% of silver and 5 % of tin or indium depending on the version.

What would be the easiest way to recover silver?

The first idea was to use hot Hcl to dissolve lead tin and indium.

On YouTube I found a video of a guy separating silver from soldering wire using an electrolytic cell. In this case I would probably have to melt all the tiny pieces to have one big electrode.

[youtube]https://youtu.be/NSRqt7WoQHU[/youtube]

Any other proposal?

Ben

After more readings I think Hcl would be the easiest solution.

1 - Hot Hcl will dissolve tin indium and lead. Only silver will remain in a solid form so I should be able to filter it.

2 - Cooling down the solution will precipitate lead.

3 - Adding NaOH will precipitate Indium but probably also tin. I could use NH4OH instead (I don't have KOH).

In the end only tin would remain in the solution. Which is not really a problem because it is not really of interest and in a very small amount.

Am I right?

Ben

Did you look into selling them as is for what they were made for, then just buying silver?

Hi,

No. The silver content worth around 30 euros and probably the same or less for indium and the market for this kind of scrap doen't really exist here in europe. And to be honest I'm more interested by the science experience than money.

Ben

6.25g silver worth 30 Euro? Sorry, 62.5g

Hi,

2.5% of 2500gr should give 62.5gr of silver. At 0.44 €/gr it's 27.5€.

Assuming there is half of tin alloy and indium alloy, at 5%, I should also find around 60gr of each.

Ben

More realistic: reduce 15% on refining and about 10 euro testing