Sciencemadness Discussion Board

Iron pyrite

guy - 17-4-2004 at 17:22

Is there anything i can do w/ iron pyrite?

The_Davster - 17-4-2004 at 18:34

Fools gold eh? Try selling it to people who dont know the difference between it and gold:D and Use the money you make to buy chemicals. But if you are wondering what to do chemically with it you could dissolve it in an acid of your choice and from there make whatever iron compound you fancy.

chemoleo - 17-4-2004 at 18:36

Hmm when I tried it FeS2 did not dissolve in HCl. No gas (H2S) evolution either, it remained unchanged.
For making Fe compounds, I would use normal iron nails for that :) - easier and cheaper :)

Geomancer - 17-4-2004 at 19:43

Hmm. I was just reading that one could generate H<sub>2</sub>S with dilute HCl+iron pyrite. Then again, that was in "The Complete Book of Ecstacy" (on Rhodium's site), which may not be an authoritative source. Chapter 3, under HI.

Industrially, iron pyrite is used as a sulphur source, for the production of sulphuric acid, both by roasting for SO<sub>2</sub> to feed the contact and lead chamber processes, and by converting to ferric? sulphate, for the clay pot process.

guy - 17-4-2004 at 20:37

i put it in H2O2 and bubbles formed. they were odorless. Acids don't seem to work.
After putting it in H2O2, the liquid reacted w/ NaHCO3 to form CO2

guy - 17-4-2004 at 21:43

Maybe the reaction is

FeS2 + H2O2 --> Fe(OH)2 + H2SO4
then the acid reacted w/ the iron hydroxide to form the bubbles.

That explains why it took a while for the bubbles to form.

The_Davster - 17-4-2004 at 22:05

The FeS2 could have acted as a catalyst for H2O2 decomposition, like MnO2, to form oxygen bubbles. You should try to collect the gas produced and do the glowing splint test.

guy - 17-4-2004 at 22:15

http://www.mines.edu/fs_home/jhoran/ch126/app.htm

This website shows the oxidation of FeS2 with Hydrogen peroxide

The_Davster - 17-4-2004 at 22:58

Wow, personally, I'm surprised that sulfuric acid is produced. I guess I was partially wrong.
2 H2O2 --> O2 + 2H2O
4 FeS2(s) + 15 O2(aq) + 14 H2O(l) --> 4 Fe(OH)3(s) + 8 SO42-(aq) + 16 H+(aq)
I assume that the first reaction is still catalysed by the FeS2 as I mentioned before, but then the products from the first reaction react with the FeS2 to make the sulfuric and iron hydroxide. The reaction 4 FeS2(s) + 30 H2O2(aq) --> 4 Fe(OH)3(s) + 8 SO42-(aq) + 16 H+(aq) + 16 H2O(l) is actually to overall reaction-it did not show both reaction steps which is why I did not understand why it happened.

hmm...this gives me an idea. Moisten some powdered pyrite with water and let sit untill all the "gold" color has dissappeared, periodically re-moistening to keep the pyrite at the constituency of a putty. When gold color has dissappeared squeeze out the liquid which should be some H2SO4 of decent concentration. I suppose this could be done with H2O2 but with the concentrations of it available to most of us, heavily diluted with water, the final sulfuric concentration would be pretty low. Also keeping it in a putty like state increases the surface contact with the air, supplying the oxygen necessary for the reaction.
This is begginning to sound like a good method for sulfuric, only reactants are water and fools gold, accessible to everyone.-Can anyone find any problems with this method?

Well, I'm off to dig up my mineral set I got as a child and begin some testing.:cool:

Saerynide - 18-4-2004 at 03:13

How come the ferric hydroxide wont react with the sulfuric acid to make ferric sulfate?

vulture - 18-4-2004 at 07:43

I was about to ask the same thing.

Also, oxidation of PbS with H2O2 yields PbSO4...

unionised - 18-4-2004 at 08:15

FeS2 + "o"--> FeSO4 + ??
Pyrites has an excess of sulphur compared to ferrous sulphide.
Even allowing for Fe(III) suplphate as the product would still be sulphur left over and this might be oxidised to H2SO4.
(Of course, it might just get oxidised to sulphur and sit there grinning at you).

I'm so stupid

The_Davster - 18-4-2004 at 09:06

I can't believe that I did not notice that if an acid and base are produced that they would react.:mad:

Polverone - 18-4-2004 at 10:16

According to one of the old chemistry books I have lying around, powdered iron pyrite + charcoal may be heated to produce CS2. Fun!

Theoretic - 19-4-2004 at 04:40

If the solution of sulfuric acid is dilute, iron hydroxide will not dissolve, and any present will hydrolyse. The ferric cation is very acidic, remember. Fe2+ is much less acidic, but will be quickly oxidized by air to Fe3+.
The excess sulfur will be oxidized to sulfuric acid.

guy - 19-4-2004 at 18:38

You could heat up FeS2 to make Fe2O3 and SO2.

How much heat is required though?

guy - 22-4-2004 at 20:48

Na2CO3 + FeS2 --> ?

axehandle - 22-4-2004 at 22:37

Quote:

You could heat up FeS2 to make Fe2O3 and SO2.

How much heat is required though?

From what I can remember of my H2SO4 production studies, it's a self-sustaining reaction once it's begun and the pyrite is in a pile.