Sciencemadness Discussion Board - Refining gold

Refining gold

plante1999 - 18-6-2012 at 15:40

I refined some gold plated computer part to remove major copper contamination using air, HCl and little peroxide to start the reaction (copper II chloride etching), I got gold foil pieces with a little copper. I disolved these foil with 30% HCl and a little amount of sodium hypochlorite 12% sol. to make a diluted quite pure diluted Chloro auric acid sol. Then I added very diluted ferrous sulphate solution to precipitate the purified gold. The sol. of the reaction turned quite dark brown, now I wait to lets the powder decant. Wath Can I do with gold powder? Any interesting use? I have tough to make gold II oxide by dissolving the gold and precipitating it with sodium hydroxide, and use it as an oxidizer (quite costly actually).

[Edited on 18-6-2012 by plante1999]

cyanureeves - 18-6-2012 at 16:33

about five times now i have tore down computer parts for the gold and only once recovered a tiny b.b. from now on i will either keep the foils as is or drop the gold from the auric chloride solution with ammonium hydroxide and get the red gold dust. sodium metabisulphate has only worked for me when i dissolved rings and other jewelry. about 4 times i couldnt even drop a significant amount of gold from 1/20 kt. rg. i will go for the red gold on that next time too. the red ammonia gold can be added to a plating solution at least ,some people explode the red gold.

plante1999 - 19-6-2012 at 03:45

I got 0.1g of pure fine brown gold powder! Now I will refine more Electronic waste to get 1g of it and then I will make experiment with it. The powder look much like the powder in this video at 5:00

http://www.youtube.com/watch?v=Hv4CcaTVJqY

blogfast25 - 19-6-2012 at 06:21

As long as you're not trying to make a profit, because that's very hard on a small scale...

I got a bit of gold dust from one mobile a few weeks back.

plante1999 - 19-6-2012 at 07:32

Quote: Originally posted by blogfast25

As long as you're not trying to make a profit, because that's very hard on a small scale...

I got a bit of gold dust from one mobile a few weeks back.

I'm not looking to make profit, only to get OTC free gold.
How much gold did you get?

blogfast25 - 19-6-2012 at 08:13

I haven't weighed it yet. I guess about 0.1 g.

I dissolved first in HNO3 70 % to remove copper and other non-noble metals. Then Aqua Regia on the residue. I precipitated with metabisulphite, after part neutralising. Redissolving the gold in AR gave no blue or green whatsoever, so it's pure gold, perhaps with small amounts of Pt or Pd...

[Edited on 20-6-2012 by blogfast25]

plante1999 - 19-6-2012 at 12:11

I attempted tomake gold oxide by dumping conssentre chloro auric acid in sodium carbonate but nothing precipitated even after a few minutes, so I re-acidified my sol. and used again ferrous sulfate to precipitate it, I dont think I will get much gold now, I think I spoilled my gold...

blogfast25 - 20-6-2012 at 04:53

Quote: Originally posted by plante1999

I attempted tomake gold oxide by dumping conssentre chloro auric acid in sodium carbonate but nothing precipitated even after a few minutes, so I re-acidified my sol. and used again ferrous sulfate to precipitate it, I dont think I will get much gold now, I think I spoilled my gold...

Nothing ever gets lost in chemistry, plante, just mixed in with other stuff

...

Poppy - 31-10-2012 at 17:45

I got such a mishap with my gold refining too. The yield was expected to approach 1g, but I distrusted sodium bisulfite reducting power and added a lot of it. The resulft was chevreul's salts mistaken as silver and gold climbing somewhere into it.
Now I have 1g gold spreaded over 4L solution lol. If gold really precipitated I shud have no difficulties redissolving chevreul's salts and recovering gold even if its inside such a large vessel.

violet sin - 31-10-2012 at 21:30

but in 4L of sol. better than spread over the desk... I bought a few large boxes of OLD cell phones really cheap when a long time local repair shop/service provider went under. after picking off all the easy spring terminals and what not, and dissolving the copper, I had a decent pile of gold flake. it filled a small vial 90%(5ml) but I noticed a bit of copper still in there on the backsides of some of it. so I added peroxide and HCl to let it etch away the residual... stayed up too long cleaning the other phases of the process up to make more and decided to go to bed. but not before I put the top on the vial and a few moments later I heard a faint "pop!" I was in disbelief when I could not locate the vial.., but did find portions(1/2 at best) of my gold... in a several foot splatter pattern.
never did that again. but have made more bb's of gold.

Eddygp - 1-11-2012 at 08:23

Try to make some organic chemistry with gold. It is a bit difficult but really satisfactory (the chloro(dimethyl sulfide)gold(I) is incredible). Or you may try to make some interesting chloroaurates.

platedish29 - 1-11-2012 at 19:02

Impure gold stains, a bit, flush ...
This coordinated organic compound of yours, is probably worth the trickery.