Metal finishing Q&As since 1989

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Recovering silver via electroplating thum cell

I'm doing silver refining by using thum cell and my electrolyte is silver nitrate [on eBay or Amazon].
Initial electrolyte conc. is 65 g/L of silver, my problem is that I m getting dissolution of silver anode in solution but I m not getting silver particle at cathode plate.

Syed Ali
refining - Pakistan
2005

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2005

You may want to check the following;

1.Check your connections to the rectifier, anode and cathode to make sure they are tight.
2.Check the filter cloth in the anode basket, it may have too tight of a weave.
3.Check the spacing between the anode and cathode. it should be 3 to 4 inches (7.5 to 10 cm).
4.Check the size of the cathode, it should be 1.2 to 1.5 larger than the surface area of the anode.
5.Check the purity of your scrap anode, the starting purity should be .940 or better for best results.

Usual power settings for Thum Cell;
Volts per cell - 3 to 4.4
Amperes per cell - 150 to 200
Current density (amps per sq.ft) anode - 50 to 57
Electrolyte;
Silver gpl - 75 to 80
Copper gpl - 10 to 40 (improves conductivity)
pH - 2 to 6
tartaric acid [on eBay or Amazon] - 1/4 teaspoon as needed for denser crystal.

Good Luck & Best regards,

Jim Sivertsen
Alloys & Refining - Alden N.Y. USA

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Thanx a lot ,
I will try it , and I hope will work and as soon as I get some good results I will shere here.

Syed Ali
- Karachi, Pakistan
2006

I want to know about electrorefining of silver. I tried it with Agno3 but along with silver other impurities also get deposited on cathode. I used current density of 200A/m2. suggest me how to proceed now.

Pallavi nigam
non ferrous technology development centre - Hyderabad, India
2006