Authoritative Answers, Fun, & Aloha -- no cost, no passwords, no popups
(as an eBay Partner & Amazon Affiliate we earn from qualifying purchases)

Home /
Site 🔍
pub     mobile?
Metal finishing Q&As since 1989


Gold Recovery for Dummies?

Q. About a year and a half ago I heard you could recover the gold out of computer parts. I am a little bit of a dumpster diver and have plenty of areas where I can get computer parts from, with a lot of gold left on them so I had to wait for about 8 months before finally I found some [on eBay or Amazon (adv.)] .

My first attempt at recovering the gold was with vinegar [in bulk on eBay or Amazon (adv.)] and salt mix for my electrolyte. the connectors are used as the anode. A sheet of copper approx. 6" x 3" is my cathode.
Power is a 12 V 2 A transformer.

My theory was that the acetic acid [on eBay or Amazon (adv.)] with added sodium chloride would dissolve the copper and nickel allowing it to plate onto the copper sheet while the gold would sink to the bottom.

The first attempt seemed to follow this theory; however, I did not notice any change in the thickness of my cathode. I figured this was due to how little copper plated out prior to the gold flaking off.

Repeating the process with the already saturated mix resulted in the mix taking on more of a milky white appearance. I am guessing this batch must have had a different metal in it somewhere but I am unsure what metal would cause such a reaction. the solution also seems to have particles of corroded copper (dark green) floating on it.

my questions are: 1. any theories on what would cause this? 2. why am I still not seeing the cathode getting thicker after almost 4 weeks of total run time?

Joshua Wert
hobbyist - crescent city, California
April 7, 2009

! Dear readers! If you overheard doctors discussing an appendectomy, you would not try one based on what you heard :-)

Please remember that internet forums are a "one-room schoolhouse" where you will read snippets on subjects that may be dangerous to dabble in if you are not trained in that field. The idea of anyone who is not a trained professional chemist with haz-mat certification trying to make cyanide is frightening.

CaO or baking soda does NOT destroy cyanide; cyanide treatment requires alkaline chlorination.


Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

Q. I have a bunch of unopened bottles of precious metal glazes for ceramics.
Each says it has a net weight of 1 gram of gold or platinum.
Is there a way to recover the metal from these liquids?

Cory Christensen
hobbyist - SLC, Utah, USA
October 28, 2010

Q. Sir, I am doing the scrap gold. I got a problem in gold recovery that is, actually I am using the method of collecting the gold coated material and adding the nitric acid and giving the heat. After boiling the acid, the gold layer appearing the top, collecting the gold layer, when I try to heat that gold it becomes nothing. All coated material gone. Any suggestion on this? One problem is nickel; a extract in this method I believe that nickel combines with gold; this my case.

Mulka Kalidas
gold worker - Hyderabad, India
October 19, 2011

Q. Metal recovery from Philosophers Stone after conversion. I have been working on this process for sometime, I am not 100% certain of the yield as yet as the conversion process is a little messy - basically what is left after extraction is a fine white powder a little like talc then this is converted to metal form, it maybe more beneficial to keep in the white powder form for the properties it contains, however once converted back precious metals show and this has the higher market value at this point. Is it better to have someone else extract the metal elements from this powder rather than if I do this myself, are there any decent metal recovery company's I could send this to in Australia.

Andrew Ruselle
Opportunist - Australia
October 30, 2011


For every ounce of scrap gold you are going to refine you will need a capacity of 300 milliliter container for the aqua regia solution.

1. Place impure gold to be dissolved into a glass or plastic container.

2a. Aqua regia - Mix one part nitric acid to 3 parts hydrochloric acid. OR
2b. To the container, add 30 milliliter of nitric acid for every ounce of metal.

To the container, add 120 ml of hydrochloric or muriatic acid for every ounce of metal in the container.

3. Allow impure gold to dissolve for an hour to overnight for complete dissolution.

4. Once all gold is dissolved, filter out any particles out of the acid solution containing the liquified gold into another glass container using a fine stainless strainer. The remaining particles should not be discarded as these may contain other precious metals!

5. The acid containing the dissolved gold will be an amber to emerald green color depending on the purity of the gold and should be clear (not murky or cloudy). If the acid solution containing the dissolved gold is murky, it may contain particles and should be re-filtered with a finer grade paper filter.

6. Slowly, add the water/urea (urine ) to the acid solution containing the dissolved gold. The acid solution containing the dissolved gold will foam with the addition of the water/urea (urine). Do not add the water/urea (urine) so quickly that the acid foams out of its container. When the acid solution containing the dissolved gold stops reacting to the addition of water/urea (urine), stop adding the water/urea (urine). You've just raised the pH of the acid from 0.1 To 1.0, killing the nitric acid but not the hydrochloric.

7. Add precipitant ( sodium bisulfite ) slowly in minute amounts to the acid solution containing the dissolved gold, immediately the acid solution containing the dissolved gold will change to a muddy brown appearance as brown particles of gold form in the solution. Occasionally agitate the solution with a glass stir rod, as the brown particles continue to form they will sink to the bottom of the container, this brown "mud" is, despite its appearance, pure gold.

8. Allow precipitant ( sodium bisulfite ) to fully draw out all the gold out of the solution, test for gold in the remaining solution, if it tests positive for gold, you may have to add more precipitant ( sodium bisulfite ).

9. To test the solution for remaining gold, first immerse the end of the stirring rod in the acid. Remove it and touch that end to a paper towel to make a wet spot. Put a drop of gold detection liquid on the wet spot on the paper towel. If any gold is still dissolved in the acid, the wet spot will turn a purple-black or a purple-brown. If you see this color change then give the precipitant more time to work and/or add more precipitant.

10. Now all the gold should be drawn out of the solution and the acid should now be a clear amber color with a brown mud settled at the bottom.

11. Using a fine paper filter, pour off the acid into another container allowing the mud to stay in the filter. The mud is pure gold.

12. When all the acid is poured off, return the mud to a container for rinsing, add tap water to the mud. Stir and let the mud settle. Using a fine paper filter, pour off the tap water into the container with the acid. Do not pour off any particles of brown. Repeat this rinsing 3-4 times or more.

13. After completing the final tap water rinse, rinse once again with aqua ammonia [on eBay or Amazon (adv.)] ( %10 ammonia to %90 distilled water ) white vapors will appear. The aqua ammonia cleans impurities from the gold mud while, at the same time, it neutralizes any acid still clinging to the gold mud.

14. While in the fine paper filter, give the mud on last rinse, this time with distilled water until mud and filter is clean.

15. Take filter with clean gold mud and gently squeeze of any excess water and place filer with mud into crucible for melting.

16. Once melted, the gold will again take on the appearance of metal. If you've followed the instructions carefully and used filters, the gold will be 999.5 % Pure with virtually no losses.

17. Platinum- If you had platinum in your gold, it will not dissolve, to any appreciable degree, in the room temperature aqua regia. It will be left behind when you pour off the aqua regia, prior to precipitation. To insure high purity of the platinum, you will need to re-refine this material. Put this material in a fresh aqua regia bath. This time, however, heat the acid to simmering. Continue heating until all the platinum is dissolved (that may take 1-2 hours). When completely dissolved at 1 ounce of ammonium chloride for every ounce of dissolved platinum. The platinum will precipitate as a red mud. If you want to leave the iridium in the platinum, then wait for it to precipitate before recovering the platinum. Iridium will precipitate as a blue-black mud after the platinum precipitates. Platinum group metals will also show up on the stannous chloride test. Platinum turns red, palladium Palladium turns orange and iridium turn blue-black.

January 7, 2012

A. Philosophers stone? Alchemy? When using nitric acid to remove base metals in gold recovery it is very easy to misplace your gold. On electronics that use gold for shielding (such as RF shielding) the gold can be very thin and instead of coming off in foils will separate into finely divided particles and will get lost in trash. Another cause for missing gold recovered this way is bad work habits. Dirty glass that has been cross contaminated will hold chemicals that can't be seen. Did you use the glassware for any solution that contained a HCl acid solution? If so, remember that you can't rinse acids from materials. If you use a container for a HCl solution and then rinse well, and then use it for a nitric acid solution a weak aqua regia will form and dissolve values. A small amount of HCl will make quite a bit of AR solution. As far as the philosophers stone, the only one I can think of is the one in the Harry Potter stories. Values that have been precipitated have distinct colors and as far as white powder goes, metal salts can be white if crushed finely enough. If you would like some help, put the witchcraft aside and let me know what you did to get what you have and I will try to give some advise on what it is and what can be done with it.

Jeff Massey
- Decatur, Alabama, USA
January 16, 2012

(you are on the 1st page of the thread)       Next page >

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

Chemicals &
& Software

About/Contact  -  Privacy Policy  -  ©1995-2024, Pine Beach, New Jersey, USA  -  about "affil links"