Precipitation Methods.

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Noxx

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Feb 24, 2007
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Location
Quebec, Canada
When you made Gold Chloride with the Aqua Regia technique, you can either precipitate the gold in your solution with Copper, Zinc or Sodium Metabisulfide. Only use SM if you neutralised the acid with Urea. If it's not the case use copper or zinc.
Just put a little more precipitant than the amount of gold you expect.
If you expect 10g. of gold to come out, put 12g. of precipitant to be sure you won't left any gold in the solution.
 
Otherwise known as sulphite crystals, sodium metabisulphite is used in winemaking to sterilize equipment. I get mine at our local beer and wine "Hobby Brew" for 6 bucks per kg. Works like a charm to drop gold after you've killed the nitric with urea or by boiling down. You should test the solution after with gold detection fluid. Make your own with Hcl (muriatic acid at your hardware store) and tin. I use old pewter items which are about 65% tin.
 
No ! You must first neutralise the acid with urea and then precipitate with what ever method you like.
 
Noxx said:
When you made Gold Chloride with the Aqua Regia technique, you can either precipitate the gold in your solution with Copper, Zinc .

That's not very good advice. Once you get your gold into solution, it's more than desirable to use a precipitant that's selective-----one that won't drag down other elements. Metals will---especially zinc. Any copper that follows the gold through the process will be precipitated along with the gold, so you haven't really improved it by much, if at all.

Have you read about the use of ferrous sulfate? Sulfur dioxide? Both of them are very selective in that they precipitate only gold, and they're easy to use. The one disadvantage is that you must evaporate any excess nitric, otherwise the process isn't very effective, and a little of the gold tends to go back into solution when you wash it after precipitation.

Harold
 
hey noxx how do you evaporate nitric or if your using aqua regia and how much gold goes back in the solution. do you fine ferrous sulfate? Sulfur dioxide. better than sodioum meta ,with your ver, the gold that goes back in the solution can it be retrived agian
 
With Aqua Regia, you do not evaporate nitric acid... you just neutralise it with urea. I don't know for the amount of gold dissolved... and I know nothing about ferrous sulfate and Sulfur dioxide pecipitation methods sorry. If there is still gold left in solution, yes you can always precipitate it again (If you haven't added anough precipitant)
 
Anyone heard of BDG ?

It's a neat liquid that has a strong attraction to gold chloride! Better even still it is not miscible with water! When Butyl Diglyme is mixed with any aqueous based gold solution and shaken, it will separate out the gold with great effieciency and selectivity! The gold can then be precipitated out of the BDG with oxalic acid, hydrazine sulfate, and several other substances. The really amazing part is that the gold comes out as beautiful gold flakes of very high purity (99+). I've include a snapshot of a very small batch I have going now.
The stuff is so cool, it is considered a green environment chemical and you can even reuse it indefinitely (with some evaporation losses)! As usual I have more info for those of you who are intereseted.

bdgsidedj6.jpg

bdgtopfv9.jpg


Steve
 
Ferro sent me four quarts for FREE !!!!

I sent them an email on their web site explaining what I was doing and inquiring about samples of the substance. I never got a reply back from them until one day about two weeks later a parcel from Ferro showed up out of the blue on my door step with TWO 2 Quart Bottles in it!!! I was shocked...BUT HAPPY.

FERRO RULES!!!

Steve
 
lazersteve said:
Anyone heard of BDG ?

It's a neat liquid that has a strong attraction to gold chloride! Better even still it is not miscible with water! When Butyle Diglyme is mixed with any aqueous based gold solution and shaken, it will separate out the gold with great effieciency and selectivity! The gold can then be precipitated out of the BDG with oxalic acid, hydrazine sulfate, and several other substances. The really amazing part is that the gold comes out as beautiful gold flakes of very high purity (99+). I've include a snapshot of a very small batch I have going now.
The stuff is so cool, it is considered a green environment chemical and you can even reuse it indefinitely (with some evaporation losses)! As usual I have more info for those of you who are intereseted.
Steve
I'd definitely avoid the hydrazine sulfate, as hydrazine is an insidious poison. But, oxalic acid sounds pretty benign. I'd sure like to try this out myself! I sure don't want to get 4 L of the BDG delivered to me, however. I wonder if it will work with the cyanide stuff I'm using?

Thanks,
 
Thanks for the info.
I have heard of this before about a year ago
a site called Goldmineworld.net had it for sale
under the name gold stripper but they stopped selling it
sounds like it may work good let us know more
 
Socorban,

The BDG doesn't dissolve metallic gold, only gold in combined form like gold chloride. You must first get the gold into solution using AR, Acid-Peroxide, Chlorine Water, or any other chemical mix that will dissolve gold into solution. If you can filter the gold out of a liquid it is not in solution. If you test a solution with the stannous chloride test and it shows positive the BDG will extract the gold into the ethereal layer (upper layer).

Here's the link to the formula for stannous chloride:

Ante Up, Gold Diggers!

Steve
 
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