Hi
I am a nubbie at this and need a bit of help please.
I had about 20 DIMMs and a couple of cell phone pcb boards and covered with hcl in a beaker on hot plate.
Added small amounts of Nitric Acid until gold was gone.
This left a very dark green solution.
I cooled then filtered the solution and added Sodium bisulphate to precipitate the gold.
I left the solution for 20 hours and tested using Stannous Chloride (I wasn't sure how to make up the Stannous powder so I mixed 50/50 with water) This did not change colour it stayed clear.
I assumed all gold had been precipitated but when I poured off the liquid there was only a kind of heavy white material hanging in the solution at the bottom.
All the gold has gone from the pcb boards so I assume the gold is still in the solution.
Any ideas as to where I went wrong and what I can do?
Thanks
Rich
I am a nubbie at this and need a bit of help please.
I had about 20 DIMMs and a couple of cell phone pcb boards and covered with hcl in a beaker on hot plate.
Added small amounts of Nitric Acid until gold was gone.
This left a very dark green solution.
I cooled then filtered the solution and added Sodium bisulphate to precipitate the gold.
I left the solution for 20 hours and tested using Stannous Chloride (I wasn't sure how to make up the Stannous powder so I mixed 50/50 with water) This did not change colour it stayed clear.
I assumed all gold had been precipitated but when I poured off the liquid there was only a kind of heavy white material hanging in the solution at the bottom.
All the gold has gone from the pcb boards so I assume the gold is still in the solution.
Any ideas as to where I went wrong and what I can do?
Thanks
Rich