chornedsnorkack
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Aqueous gold sulfate?
Does gold form salts with simple noncomplexing acids - gold (III) sulfate, nitrate, perchlorate?
Obviously gold is not dissolved by noncomplexing acids - it is harder to oxidize than oxygen.
But gold hydroxide and oxide are well known - when bases are applied to gold chloride/tetrachloroaurate solutions, gold hydroxide precipitates and
does not evolve oxygen unless heated over 150 Celsius.
So, if a gold hydroxide precipitate is washed clean of complexing halide ions and then treated wit strong noncomplexid acids, does it dissolve?
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blogfast25
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Try this:
http://www.mjcce.org.mk/PDF/15_1_212.pdf
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cyanureeves
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wow you can electrolyze gold in sulfuric acid get gold sulfate,dry it and add acetic acid and cook that and get releasion of acetic acid and gold
oxide. i didnt know releasion was a word and even google spell check is scratching its head,probably over the gold oxide thing. gold oxide and nitric
maybe? Gold Acetate? any how didnt someone here post something about gold thiosulphate or something as an alternative for cyanide dissolving?
[Edited on 17-6-2012 by cyanureeves]
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AJKOER
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OK, of possible interest is:
"it was found that fast gold dissolution rates can be obtained using ferric oxalate in the presence of thiourea as a catalyst. The ratio of oxalate to
ferric is also very important to gold leaching as this ratio governs the speciation and reactivity of the oxidant. At low Ox/Fe ratios, the gold
dissolution rate was found to be initially high, but decays due to the homogeneous reduction of the ferric complex. Electrochemical studies of the
reduction of ferric oxalate showed that the more oxidizing Fe(C2O4)2(-) is reactive towards thiosulfate and/or thiourea, whereas the
Fe(C2O4)3(3)(-)complex is stable, and hence at an Ox/Fe mole ratio of 3, the gold dissolution rate does not change with time. "
Source: Abstract of "A fundamental study of ferric oxalate for dissolving gold in thiosulfate solutions" by I Chandra, M I Jeffrey.
Link: http://www.mendeley.com/research/fundamental-study-ferric-ox...
However, oxalates do form complexes so this answer may not count. Also, from Gold refining websites, I see the mention of HCl + NaClO3. This actually
produces a solution of Chlorine water and ClO2 as:
2 HCl03 +2 HCl <==> 2 Cl02+1/2 Cl2+2 H20
If this works, this is very similar to the use of Aqua regia (a 1:3 mixture of nitric acid and hydrochloric acid) which dissolves gold with the
replacement of HNO3 with HClO3. Note, Wikipedia (http://en.wikipedia.org/wiki/Gold) does mentions that some free halogens do directly react with gold (cited reference: [87] Wiberg, Egon; Wiberg,
Nils and Holleman, Arnold Frederick (2001). Inorganic Chemistry (101 ed.). Academic Press. p. 1286. ISBN 0-12-352651-5.) Apparently, per [87]
Fluorine will attach Au and Pt at a dull red heat. Also, per Wiki, "chloroauric acid (gold chloride-hydrochloric acid) ...is made by dissolving gold
with chlorine gas in the presence of hydrochloric acid" (link: http://en.wikipedia.org/wiki/Gold_parting). Wiki (link: http://en.wikipedia.org/wiki/Selenium ) states that hot concentrated H2SeO3 (Selenic acid) is capable of dissolving Gold forming Gold(III)
selenate, so this is your answer. Note, reacting Gold(III) selenate with Barium (or Copper or Lead) perchlorate may form Gold perchlorate and an
insoluble selenate salt.
Equation reference: "A comprehensive treatise on inorganic and theoretical chemistry", Volume 2 By Joseph William Mellor, page 288, link: http://books.google.com/books?pg=PA288&lpg=PA288&dq=...
[Edited on 18-6-2012 by AJKOER]
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cyanureeves
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ferric oxalate and iron oxalate, are they the same thing? i think i can do the one on you tube using oxalic acid and iron sulfate. this oxalate is
very interesting and it turns pyrolike with air alone. this guy bubbles it using heat and it looks like liquid bubbling but its just carbon dioxide
making it look like fluid.its just as pretty as gold dust if not prettier. the one method discribed here is a bit different and more complicated to
make. in the presence of thiourea sounds like that blind faith song lyric. i never got this in the presence thing:in the presence as in close
proximity,making or not making contact with the other reactants?
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woelen
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Ferric oxalate is a complex of iron(III) and oxalate. It has a lime green color. Usually it comes as the ammonium salt or potassium salt:
K3[Fe(C2O4)3].
Iron oxalate can be the iron(II) complex and the iron(III) complex. A more specific name would be ferrous oxalate. It is a golden yellow solid.
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