Green Aqua regia

[jmusac]

Hi,
Begginer here. I obtained 715g of computer memory gold fingers.
I followed this video for gold recovery:


Everything was ok until 12:00 minute mark and aqua reqia part. My aqua regia turned green instead of yellow (see picture)



What did I do wrong and is there a way to fix this ?

 

[FrugalRefiner]

The green color is likely due to some copper and/or nickel being dissolved in the AR. It's not a big problem. Precipitate the gold as planned.

Dave

 

[jmusac]

Thanks

 

[Yggdrasil]

Thanks

Most use plain Nitric or Cupric Chloride for releasing the foils.
It is then much easier to deal with only the Gold foils.

 

[Marcel]

Gold on PCBs is almost always plated onto a nickel layer over copper. So if you dissolve the copper using the acid peroxide (AP) method, there should always be nickel on the backside of the flakes. If the gold plating was relatively thin (good ones are 8 µm to 16 µm), you'll get proportionally more nickel compared to thicker gold-plated traces.