Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

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DIY elution & electrowinning system (1 reply)

J
oro
5 years ago
oro 5 years ago

I’m wondering if I’m in the ballpark with this and how scaleable it might be.

2.5 L of solution
1% cyanide
1% sodium hydroxide
2% alcohol

- 700g of activated carbon w/ aprox 2-3 g of gold
- carbon is wrapped in mosquito netting
- anode is a carbon / graphite rod
- cathode is steel wool wrapped in a coffee filter
- power supply is 1 amp - either 6 or 12 volt (?)
- heat at 80 C

It’s a bit cramped in the Pyrex as you can see in the photo. Does position of the electrodes matter? Can they touch the carbon without issue?

The pH started out at 13 and dropped to 11 after 2 hours

The solution started to turn yellow within 15 minutes

I read it can take 30-40 hours or more to reach optimum recovery.

I actually need to do 5-10 kg batches for leach tests.  Am I on the right path?

stripper 2
https://www.911metallurgist.com/wp-content/uploads/2018/12/stripper-2.jpg
stripper 1
https://www.911metallurgist.com/wp-content/uploads/2018/12/stripper-1.jpg
J
oro
5 years ago
oro 5 years ago
Like

Next day update...unfortunately the whole thing evaporated overnight! ...but seems like it worked, nice gold wool.

I assume a single vessel to heat and electrowin can only be done using non conductive ceramic / porcelain or similar material, therefore a limited capacity, more or less 1 kg of of activated carbon. Yes? A 5-10 kg capacity would need to be two vessels, a steel pot on a burner and then pump / or manually transfer the liquid to a second stage electrowin cel and then pump / transfer back to steel pot...more or less yes?

gold wool
https://www.911metallurgist.com/wp-content/uploads/2018/12/gold-wool.jpg

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