Hi there,
I'm a Pure Science undergrad from London. I've been interested in gold extraction for a while, and have been reading up on it since September (between studies).
I spent as much as I could on it, but after a while found a great deal of inconsistencies with different people's methods/explination due to a lack of practical knowledge on my part, and so I thought I'd try and get some hands on experience to help contextualise what I'm reading on this forum.
So for my first experiment I took 512g of gold fingers dissolved that in [100ml nitric acid / 300ml HCL ]
I got a positive test with Stannous solution
I then neutralised with sodium carbonate and added some food grade sodium metabisulfite dissolved in water to precipitate 4.42g of a murky grey brown powder.
[for context the SMB was purchased from a chemical supplier]
I then tested this with Stannous to confirm a gold content, and it was positive.
I then dissolved in Aqua Regia [ 25ml nitric / 75ml HCL ] and filtered out the flakes of plastic
I now had a dark tan solution testing positive with Stannous, and neutralised this slowly with urea until it stopped bubbling.
I filtered to remove the dead urea left floating and on the bottom and was left with a transparent yellow solution.
This is where i'm slightly lost, I decanted 10ml into a seperate beaker and added some Sodium MetaBisulfate dissolved in water, and there was no reaction.
[This SMB was purchased in the form of Campden tablets from Wilkinsons]
I added some sodium bicarbonate and it fizzed up white foam with what appeared to be patches of dark purple/red in parts of the foam.
The clear liquid now had several small flakes of an almost black substance floating in it but nothing else.
I then went back to the Laptop and tried to read my way out of it, to no avail.
so I went back and added some SMB dissolved in water to the main solution, there was a quick almost explosive bubbling from the point where the SMB sol. hit the neutralised AR, but no foam and it quickly stopped. I then added more but there was no reaction.
I left it overnight in the windowsill while i read up more about it, and with no progress went to retreive it today and it's now slightly paler, with a full growth of 2cm long very thin crystals on the bottom.
Can anyone offer any pointers on where i've gone wrong here?
Does anyone recognise any of the symptoms?
Many thanks
Mr.Snow
I'm a Pure Science undergrad from London. I've been interested in gold extraction for a while, and have been reading up on it since September (between studies).
I spent as much as I could on it, but after a while found a great deal of inconsistencies with different people's methods/explination due to a lack of practical knowledge on my part, and so I thought I'd try and get some hands on experience to help contextualise what I'm reading on this forum.
So for my first experiment I took 512g of gold fingers dissolved that in [100ml nitric acid / 300ml HCL ]
I got a positive test with Stannous solution
I then neutralised with sodium carbonate and added some food grade sodium metabisulfite dissolved in water to precipitate 4.42g of a murky grey brown powder.
[for context the SMB was purchased from a chemical supplier]
I then tested this with Stannous to confirm a gold content, and it was positive.
I then dissolved in Aqua Regia [ 25ml nitric / 75ml HCL ] and filtered out the flakes of plastic
I now had a dark tan solution testing positive with Stannous, and neutralised this slowly with urea until it stopped bubbling.
I filtered to remove the dead urea left floating and on the bottom and was left with a transparent yellow solution.
This is where i'm slightly lost, I decanted 10ml into a seperate beaker and added some Sodium MetaBisulfate dissolved in water, and there was no reaction.
[This SMB was purchased in the form of Campden tablets from Wilkinsons]
I added some sodium bicarbonate and it fizzed up white foam with what appeared to be patches of dark purple/red in parts of the foam.
The clear liquid now had several small flakes of an almost black substance floating in it but nothing else.
I then went back to the Laptop and tried to read my way out of it, to no avail.
so I went back and added some SMB dissolved in water to the main solution, there was a quick almost explosive bubbling from the point where the SMB sol. hit the neutralised AR, but no foam and it quickly stopped. I then added more but there was no reaction.
I left it overnight in the windowsill while i read up more about it, and with no progress went to retreive it today and it's now slightly paler, with a full growth of 2cm long very thin crystals on the bottom.
Can anyone offer any pointers on where i've gone wrong here?
Does anyone recognise any of the symptoms?
Many thanks
Mr.Snow