Dissolving FeS2 (iron disulfide, iron pyrite)

[THX-1138]

I have some finely-divided iron disulfide, possibly mixed with some other things, that I wish to 'dissolve' away -- or at any rate remove from the mix. What would be a good way of doing this using fairly safe chemicals? (I.e., not concentrated nitric acid, although H₂SO₄ or HCl are possible.) Among the things that may be left behind are SiO₂ and microscopic amounts of gold, neither of which I'm concerned about being affected by the solvents.

 

If I heat FeS₂, won't it break down and leave me with elemental Fe and SO₂? If so, perhaps then I could act directly on the iron and make it into a soluble compound that could be dissolved and washed away..

[olmpiad]

Just react it with some HCl, the Fe will go into solution, and the S will be given off as H2S.

[YT2095]

Heat It, it will Then decompose, most acids won`t touch it.

[THX-1138]

'S what I thought. However, I haven't been able to find any reference for the temperature at which it starts to break down. Any pointers?

 

Ta..