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CHRIS25
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extract antimony from HCl
In the process of making Tin (2) Chloride and know that for every 100g of pewter I will have 8 grams of antimony in the HCl solution. A little bit of
research seems to suggest that, for a kitchen chemist, extracting this is impossible, am I right?
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
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bismuthate
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Nope just add some zinc and a bit more HCL to the solution and burn off the escaping gas. At the bottom of the vessel you use you should have tin
metal which can be dissolved in HCl. Be very careful this makes stibine gas.
Although the best thing to do would be to dissolve the pewter in HNO3 and filter off the antimony oxide. You should then have a solution of tin
nitrates (which you should purify further via).
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CHRIS25
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Then to be honest I do not want to go down there, I know that stibine is highly toxic. But thanks for responding.
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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blogfast25
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Quote: Originally posted by bismuthate  | Nope just add some zinc and a bit more HCL to the solution and burn off the escaping gas. At the bottom of the vessel you use you should have tin
metal which can be dissolved in HCl. Be very careful this makes stibine gas.
Although the best thing to do would be to dissolve the pewter in HNO3 and filter off the antimony oxide. You should then have a solution of tin
nitrates (which you should purify further via). |
Tin cannot make stibine gas (SbH<sub>3</sub> .
Tin and antimony can be separated in various ways, none of which are particularly easy to do.
One way is to add copper wire to the solution: antimony (III) is reduced to Sb (0), which precipitates as a black coating on the copper: 3 Cu(0) + 2
Sb(III) === > 3 Cu(II) + 2 Sb(0).
Tin is not reduced by copper.
It's the basis of a forensic screening test for arsenic, which is also reduced by copper (but thus cannot be distinguished from Sb).
Of course then you'll need to separate the copper and tin.
Another ways is to dissolve the pewter in HCl, then add peroxide and KCl. On cooling K<sub>2</sub>SnCl</sub>6</sub>
crystallises out but the antimony remains in solution.
| Quote: Originally posted by CHRIS25 | | Then to be honest I do not want to go down there, I know that stibine is highly toxic. But thanks for responding. |
Trust me, the amount of stibine you'll be generating is so small it's negligible. If you've dissolved pewter in HCl you've in fact already made small
amounts of SbH3!
But dissolving pewter in HCl is a real slow boat to China: you need nitric acid + HCl for that dissolution.
[Edited on 22-4-2014 by blogfast25]
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CHRIS25
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But when the tin chloride has precipitated out of my HCl solution and I have filtered it off, I am left with antimony (8%) and copper (2%) in the HCl
solution. Where is the point in adding KCl and Peroxide to get a potassium tin chloride precipitate, or have I misunderstood your explanation.
Missed your last, that's ok, heating it makes it go super fast.
[Edited on 22-4-2014 by CHRIS25]
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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blogfast25
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C25:
My turn to be confused now.
Have you (or not) dissolved pewter in hot HCl?
If 'yes', how did you precipitate out the tin chloride? By evaporative crystallisation? Or by some other means?
[Edited on 22-4-2014 by blogfast25]
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CHRIS25
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Hi Blogfast, The reaction is proceeding without heating at the moment due to the weather, (it is under a bucket outside to keep out of the rain), I
can only heat it when I am able to take my electrics and hotplate outside. I started it yesterday and it is already becoming milky. The tin 2
chloride hydrolyses in hot water, so I will keep the solution in a balanced state between warm and hot (subjectively) and have kept the HCl molarity
to 7M and once again ensure an excess of HCl. I understand that SnCl2 will precipitate, as is now happening very slightly by the appearance of the
milky white.
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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HgDinis25
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| Quote: Originally posted by bismuthate | Nope just add some zinc and a bit more HCL to the solution and burn off the escaping gas. At the bottom of the vessel you use you should have tin
metal which can be dissolved in HCl. Be very careful this makes stibine gas.
Although the best thing to do would be to dissolve the pewter in HNO3 and filter off the antimony oxide. You should then have a solution of tin
nitrates (which you should purify further via). |
To produce any reasonable amount of Tin Nitrate a very low concentration of Nitric Acid ust be used. Usually, the reaction only yelds metastannic
acid, wich readly decomposes to Tin Dioxide.
http://www.neymetals.com/tin.htm
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Zephyr
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Wait, am I missing something?
When I dissolved tin antimony solder with 30% HCl, a black crystalline solid was left behind.
I assumed this was antimony, because of antimony's resistance to acid.
I know wikipedia isn't a good source, but it says "Antimony is resistant to attack by acids."
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CHRIS25
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| Quote: Originally posted by Pinkhippo11 | Wait, am I missing something?
When I dissolved tin antimony solder with 30% HCl, a black crystalline solid was left behind.
I assumed this was antimony, because of antimony's resistance to acid.
I know wikipedia isn't a good source, but it says "Antimony is resistant to attack by acids." |
It is
misleading, in the presence of Oxygen Anitmony dissolves. So in effect any solution that contains water (dilute acid) has oxygen and dissolves the
antimony. As far as your solder is concerned I would imagine that the black is Tin. The actual colour being a thin oxidized layer since my pewter is
blackened in the HCl solution while it is dissolving, actually the proper colour tin is actually black in cornwall and devon where they are famous for
it.
[Edited on 23-4-2014 by CHRIS25]
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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woelen
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I think I have to go with Pinkhippo11. In the presence of oxygen and chloride ions at high concentration, antimony dissolves in the acid as a chloro
complex. But the oxygen must be free oxygen. Oxygen (as part of water molecules) does not dissolve the antimony.
Actually, many oxidizers can dissolve antimony, when also acid and chloride ions are present. Suitable oxidizers are oxygen (from air), hydrogen
peroxide, chlorate ion, peroxodisulfate ion, chlorine, and many more. If no chloride ions are present, then antimony is much more difficult to
dissolve.
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bismuthate
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blogfast I know that tin doesn't make SbH3 and did not indicate that it did. Oh now I see! Sorry.
You could try dissolving the alloy in CuCl2 or CuSO4 (which would be slower) then filtering it and treating the Cu/Sb with a acetic acid and H2O2
solution.
Or you could add sulfur and sodium sulfide to the solution and heat it to get a solution of sodium thioantimonate and solid tin sulfide I believe.
This page discusses separating Sn and Sb.
http://tin.atomistry.com/chemical_properties.html
[Edited on 23-4-2014 by bismuthate]
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blogfast25
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C'mon bismuthate, read it again:
| Quote: Originally posted by bismuthate | At the bottom of the vessel you use you should have tin metal which can be dissolved in HCl. Be very careful this makes stibine gas.
|
I know that was sloppy use of language but that's the problem.
@Woelen:
According to Holleman's 'Inorganic Chemistry', Sb dissolves very slowly in hot HCl, with formation of SbCl<sub>3</sub> and hydrogen.
Maybe but that must be the slowest way to produce a stannous salt imaginable. At least with HCl you can use 37 w% and refluxing, to speed things up.
Even in those conditions, it's hardly fast, the last time I did it.
By far the best solvent for tin is Aqua Regia (even fairly dilute versions work well from my experience), in which it dissolves quickly. But that
produces stannic chloride. Sb dissolves in it too.
[Edited on 23-4-2014 by blogfast25]
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HgDinis25
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| Quote: Originally posted by woelen | I think I have to go with Pinkhippo11. In the presence of oxygen and chloride ions at high concentration, antimony dissolves in the acid as a chloro
complex. But the oxygen must be free oxygen. Oxygen (as part of water molecules) does not dissolve the antimony.
Actually, many oxidizers can dissolve antimony, when also acid and chloride ions are present. Suitable oxidizers are oxygen (from air), hydrogen
peroxide, chlorate ion, peroxodisulfate ion, chlorine, and many more. If no chloride ions are present, then antimony is much more difficult to
dissolve. |
Actually, if you try to dissolve an alloy of tin and antimony in HCl, tin will react first because it is more reactive in the reactive series.
Therefore, much of the HCl gets consumed producing Tin Chloride. After all Tin has dissolved there might be too little HCl to react with Antimony.
The black crystalline substance may very well be Antimony.
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CHRIS25
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At this point I thought I would post this. This reaction is almost complete, it has practically stopped bubbling.
Pewter (For arguments sake Sn) +2HCl
26g (0.22mole) + 37mLs 11.6M (0.44mole)
as the reaction progressed I actually add more HCl to a total of 1.07moles.
This is the result, the black is a granulated mass unaffecetd by this very high concentrated HCl. (even with some HCl gas loss)
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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blogfast25
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| Quote: Originally posted by CHRIS25 | At this point I thought I would post this. This reaction is almost complete, it has practically stopped bubbling.
Pewter (For arguments sake Sn) +2HCl
26g (0.22mole) + 37mLs 11.6M (0.44mole)
as the reaction progressed I actually add more HCl to a total of 1.07moles.
This is the result, the black is a granulated mass unaffecetd by this very high concentrated HCl. (even with some HCl gas loss)
|
Yes, it's likely to be antimony. But note that this doesn't mean your SnCl2 solution is entirely, 100 % free of antimony.
Decant off the supernatant liquid and add quite some more HCl to the residue, as well as some H2O2. In my experience HCl + H2O2 dissolves antimony
powder very effectively, to aqueous SbCl<sub>5</sub>. I've used this method in a synthesis.
[Edited on 23-4-2014 by blogfast25]
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CHRIS25
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Yes I read one of your exhaustive posts filled with images of your experiment with tin, very interesting reading. But Why would I turn the antimony
residue into antimony pentachloride? If I decant the liquid and boil this down, I should see SnCl2 precipitate out? And then just for fun turn the
antimony powder into the metal by heating to 650c , I have never done this except with silver mud out of nitric acid, I presume this is possible with
the antimony powder.
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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elementcollector1
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| Quote: Originally posted by CHRIS25 | | Yes I read one of your exhaustive posts filled with images of your experiment with tin, very interesting reading. But Why would I turn the antimony
residue into antimony pentachloride? If I decant the liquid and boil this down, I should see SnCl2 precipitate out? And then just for fun turn the
antimony powder into the metal by heating to 650c , I have never done this except with silver mud out of nitric acid, I presume this is possible with
the antimony powder. |
Careful with oxygen - it's real easy to get antimony to oxidize. As I was sealing up an ampoule of pure antimony powder, an invisible amount on the
neck (from pouring the fine powder in) turned into a thick white sheen of what is probably Sb2O3. In fact, you may have to do
this under inert or even vacuum atmosphere...
Elements Collected:52/87
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CHRIS25
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I do not remember the reference but I am almost certain that I read that antimony is not easily oxidized? Actuallyu I am beginning to wonder whether
I should just chuck it away? Having read quite a lot about this then to read this: http://cameochemicals.noaa.gov/chemical/2500
[Edited on 23-4-2014 by CHRIS25]
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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elementcollector1
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At room temperature? Maybe. At melting temperatures? Nope. Especially not with antimony powder.
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blogfast25
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| Quote: Originally posted by CHRIS25 | | Yes I read one of your exhaustive posts filled with images of your experiment with tin, very interesting reading. But Why would I turn the antimony
residue into antimony pentachloride? |
I was suggesting this only to confirm it is antimony. Of course it's not the only element that dissolves/is oxidised by HCl/H2O2 but in this context
it would corroborate that the residue is Sb.
Sb is generally speaking not easy to oxidise in aqueous media, as evidenced by the reduction of Sb (III) by copper.
Oxidation of an element by direct union with oxygen is an entirely different matter: different enthalpies play a part. Antimony can be made to burn in
air quite easily, for instance. That would make melting the metal powder without inert gas blanket difficult, specially for small amounts.
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CHRIS25
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I am reading quite frequently that heating/burning antimony powder is dangerous. Can you confirm this?
It has to be antimony simply because I know the source of the pewter and its copper antimony ratio.
[Edited on 23-4-2014 by CHRIS25]
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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HgDinis25
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Heating/Burning antimony is going to produce Antimony Trioxide fumes that you shouldn't breath. Besides being the dust of a metal oxide, it is
suspected that it has some carcinogenic potential for humans.
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CHRIS25
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This is how it started - This is from wikpedia: """Pewter is an alloy made of tin mixed with antimony and copper. It is soft and flexible and it can
be melted easily. It dissolves in hydrochloric acid to produce tin(II) chloride, leaving the antimony and copper behind in the hydrochloric acid."""
I thought it would be straightforward. I think I will ditch the antimony, no good drying it, see no real use for it, just thought I might add it to
my metal collection.
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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Zephyr
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The Merck index gives some more specific information regarding antimony and its resistance to attack by acid; "Not effected by cold dilute acids;
attacked by hot concentrated H2SO4; readily by aqua regia. Nitric acid, depending on the concentration, converts it to
antimonous or antimonic oxide. When finely divided it reacts with hot concentrated HCl."
In my previous experiment, when I filter off the antimony metal and evaporated the stannous chloride, which nice large crystals, I was left with a
small volume of sticky liquid that would not crystallize. I now assume this liquid was antimony chloride.
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