rooster - 17-11-2003 at 04:01
Hi! I have an interesting problem...
I have some antimony trioxide lying around. I want to convert this to trisulphide(trisulfide?). Any ideas?
What I thought of was making a soluble salt of the antimony, maybe nitrate or chloride?
Then precipitating it with thioacetamide as we did in analysis in high school. Will this work, and is there a better way, cause thioacetamide is quite
costly...
Oh! And it is important that the final product is almost free of acid. Thats why the H2S route to precipitation is not an option. Also I have got no
H2S.
Anybody got any ideas?
[Edited on 19-11-2003 by rooster]
Marvin - 19-11-2003 at 12:26
If you are wanting to use this in pyrotechnics instead of stibnite I have some bad news. What youd get instead of the black crystaline material is
usually an orange/red powder and supposidly its not useful for pyrotechnics. The only real difference is the partical size, but colloidal amtimony
sulphide might not be what you had in mind.
chemoleo - 19-11-2003 at 17:16
I am just speaking out of my gut here, with no backup whatsoever (wow thats unusual 
)
maybe reduce the antimony via the thermite route or whatever to antimony as an element, and react this with solid sulphur in stoichiometric
amounts.....thats an idea ey?
rooster - 20-11-2003 at 04:27
Yes, I intended to use it for pyrotechnics...
Can not just the colloidal material be ground to a fine dust? I suppose it will be the same...
Anyways, it is not all that important, more of a curiosity.
Also, I only have a couple of hudred grams, so I think it would not be worth the time consumed making it.
Thanks for the replys.
vulture - 20-11-2003 at 06:36
Dissolve in HNO3 and precipitate with Na2S?
That should yield a fairly pure product.
Use a little excess Sb2O3, so you don't have any residual HNO3 left. Filter out the remaining Sb2O3.
Precipitate Sb2S3 with Na2S. Gently heat the product to drive out any H2S.
Then proceed to strongly heat the product under oxygen free atmosphere, it'll then convert to antimonite.