reclaiming gold with ether

[Geo]

while doing some study on another topic, i came across this tid-bit of information. could this be a possible reclamation process? it seems very simple.

Wet gilding is effected by means of a dilute solution of gold(III) chloride with twice its quantity of ether. The liquids are agitated and allowed to rest, when the ether separates and floats on the surface of the acid. The whole mixture is then poured into a funnel with a small aperture, and allowed to rest for some time, when the acid is run off and the ether separated. The ether will be found to have taken up all the gold from the acid, and may be used for gilding iron or steel, for which purpose the metal is polished with fine emery and spirits of wine. The ether is then applied with a small brush, and as it evaporates it deposits the gold, which can now be heated and polished. For small delicate figures, a pen or a fine brush may be used for laying on the ether solution. The gold(III) chloride can also be dissolved in water in electroless plating wherein the gold is slowly reduced out of solution onto the surface to be gilded. When this technique is used on the second surface of glass and backed with silver, it is known as "Angel gilding".

will this work with "dirty" solutions?

Gold(III) chloride, traditionally called auric chloride, is a chemical compound of gold and chlorine. With the molecular formula Au2Cl6, the name gold trichloride is a simplification, referring to the empirical formula. The Roman numerals in the name indicate that the gold has an oxidation state of +3, which is common for gold compounds. There is also another related chloride of gold, gold(I) chloride (AuCl). Chloroauric acid, HAuCl4, the product formed when gold dissolves in aqua regia, is sometimes referred to as "gold chloride", "acid gold trichloride" or even "gold(III) chloride trihydrate." Gold(III) chloride is very hygroscopic and highly soluble in water as well as ethanol.

 

[Geo]

anyone have any thoughts on this? apparently no one has tried yet. the source of the information is wiki. i know that even wiki isnt infallible and they leave out whether something will kill you. whats the dangers of adding ether to AR solution.

 

[ericrm]

geo this is realy like bdg... ether act as a solvant for gold chloride leaving everything else behind (faster said than done). i have got the chance to play a little with bdg and it is nice (it have its + and -)

as ether is very flamable i would not use it ...

 

[Lino1406]

The nice part here is the gilding - implying
chlorine is discharged?

 

[Geo]

BDG is very expensive and hard for me to source. ether on the other hand can be found at any auto parts store. im just concerned about adding ether to a nitric acid based solution. i am assuming the nitric acid would first need to be neutralized or depleted. this may not be the case, thats why i would like to get one of our chemist to chime in.

 

[chemdom]

In theory acids like HCl, HBr and HI are know to cleave C-O bonds from ethers. The reactivity goes down from HI to HCl, and heat has to be applied to cleave the bonds, thereby producing alkyl halides,which are volatile and known carcinogens. Without heat there should not be much of a problem in my opinion.

 

[freechemist]

Hi Geo,

Not having visited the forum for nearly four months, nevertheless I try to answer your Gold reclaiming questions from March 3^rd now, with hopefully a simple, practice-oriented view.

Like ericrm says, "common" ether (diethyl-ether) acts as an organic solvent for HAuCl₄, much like BDG does. In contrast to BDG, diethyl-ether is extremely volatile (boiling point 35^oC) and highly flammable, therefor imposing a high risk of fire on every work done with it. Both solvents, BDG and diethyl-ether, extract HAuCl₄ from aqueous solution as an ion-pair, formed from H₃O⁺-cations and AuCl₄^--anions, together with small amounts of water and may be, also some HCl.

Yes, this extraction works with "dirty" solutions, too. Base metals usually are not coextracted, and the procedure is highly selective for gold, that means: dissolved Pt and Pd (and others) remain in the aqueous phase. On the other hand, good old SO₂ (SMB / sodium sulfite) usually does an excellent job in reducing only gold, quantitatively, even in highly acidic solution, not affecting Pt and/or Pd, yielding quite pure, metallic gold, being purified easily in a last refining-step. - Thus, why introduce an additional extraction-step into the reclamation procedure, and use much more expensive organic solvents, compared to cheap inorganic reducing agents, like SO₂ and others?

Regards, freechemist

 

[butcher]

To me this sounds like more of a method of making an electroless plating solution, than a recover method.

 

[Geo]

thank you freechemist, its something i may never try but its always good to know if you do need it. i would never recommend a process using flammable material without knowing about it first.thankfully, i have not had a serious accident above getting a few drops of nitric on my finger. ive actually been dealing with acids for many years. i would try the process just for the experience so that i can comment from first hand knowledge. i have been guilty of boiling flammable liquids before.
please, for any new readers and new members, please dont try this for anything that i have said. like ive said, i have done this before and know how to minimize the dangers.