Hi everyone,
First a little introduction: I've been practicing chemistry as a profession and as an amateur for years, but I'm more on the organic side of chemistry. I'm pretty bad with inorganic Chem and metals.
12 month ago I decided to get into gold recycling. I took all the computer part I've kept for years out of the scelling and got started, but it didn't went that well.
I first separated the gold from electronic with HCl +O2, then filtered it and dissolved it in Aqua Regia.
The solution is now quite transparent (due to several mistakes, including the use of non-Pyrex glass when heating, making my grass highly valuable, and making me loose approximately 3 liters of tears) but I was sure there was gold in it.
I then added a saturated solution of sodium metabisulfire without neutralizing the solution (I'm still not sure if that was a mistake :/)
I was very happy as I smelled the awfull SO2, and even more when I noticed a yellowish-reddish dust precipitating (after spitting out my left lung and putting on my gas mask of course)
But I was a bit concerned. Gold is supposed to precipitate fast in a black powder in presence of SO2. Not a pinkish dust over 4h.
As I have the luck to have access to analytic equipment I runned a RX spectrum on both the solution and the dust. Turns out the dust is mainly copper and the gold is still in solution
For now 6 month (gosh 6 months...) I've add metabisulfate and HCl, a bit randomly I must confess , trying to make a lot of SO2, stirring the solution before letting it sit for weeks in hope to precipitate something. Experimenting but with poor results.
Now I'm seeking help because I'm getting a bit depressed about this as any of my attempts fail.
Do you have any idea of how I could get the pure gold back? I'm sure the gold is here, but I'm not sure of what is dissolved with it. I think there is Cu2+, and maybe HCl, HNO3, and metabisulfate.
I can't get rid of all the copper with metabisulfate, because I may get beyond the point of equivalence and start precipitating gold that I will discard (and because that is taking too long... 6 month...)
I think about electrolysis but I'm not sure at all this will work. Or maybe adding metallic copper to reduce the gold in the metal form ? I know it work for silver, but I'm not sure if this can apply to gold, especially gold chloride.
Actually I'm thinking about burning everything at 450°C to décompose everything, and put what's left in nitric acid to get rid of any trace metal... (or just burning everything as I'm really tired of this mess)
Now I know that experimenting can be fun, except when each failed experiment is worth ~100€
Anyway, thank for reading, if you have any idea of a method i could try, or if you ever got in my situation and sort it out, please let me now ^^
First a little introduction: I've been practicing chemistry as a profession and as an amateur for years, but I'm more on the organic side of chemistry. I'm pretty bad with inorganic Chem and metals.
12 month ago I decided to get into gold recycling. I took all the computer part I've kept for years out of the scelling and got started, but it didn't went that well.
I first separated the gold from electronic with HCl +O2, then filtered it and dissolved it in Aqua Regia.
The solution is now quite transparent (due to several mistakes, including the use of non-Pyrex glass when heating, making my grass highly valuable, and making me loose approximately 3 liters of tears) but I was sure there was gold in it.
I then added a saturated solution of sodium metabisulfire without neutralizing the solution (I'm still not sure if that was a mistake :/)
I was very happy as I smelled the awfull SO2, and even more when I noticed a yellowish-reddish dust precipitating (after spitting out my left lung and putting on my gas mask of course)
But I was a bit concerned. Gold is supposed to precipitate fast in a black powder in presence of SO2. Not a pinkish dust over 4h.
As I have the luck to have access to analytic equipment I runned a RX spectrum on both the solution and the dust. Turns out the dust is mainly copper and the gold is still in solution
For now 6 month (gosh 6 months...) I've add metabisulfate and HCl, a bit randomly I must confess
, trying to make a lot of SO2, stirring the solution before letting it sit for weeks in hope to precipitate something. Experimenting but with poor results. Now I'm seeking help because I'm getting a bit depressed about this as any of my attempts fail.
Do you have any idea of how I could get the pure gold back? I'm sure the gold is here, but I'm not sure of what is dissolved with it. I think there is Cu2+, and maybe HCl, HNO3, and metabisulfate.
I can't get rid of all the copper with metabisulfate, because I may get beyond the point of equivalence and start precipitating gold that I will discard (and because that is taking too long... 6 month...)
I think about electrolysis but I'm not sure at all this will work. Or maybe adding metallic copper to reduce the gold in the metal form ? I know it work for silver, but I'm not sure if this can apply to gold, especially gold chloride.
Actually I'm thinking about burning everything at 450°C to décompose everything, and put what's left in nitric acid to get rid of any trace metal... (or just burning everything as I'm really tired of this mess)
Now I know that experimenting can be fun, except when each failed experiment is worth ~100€
Anyway, thank for reading, if you have any idea of a method i could try, or if you ever got in my situation and sort it out, please let me now ^^
