symboom - 5-7-2018 at 22:15
So there is this solution for cleaning guns called cold blueing
The solution containes phosphoric acid nitric acid and selinium dioxide what is the best way to extract
My idea is heating the solution with sulfuric acid to drive off the nitric acid and shift the equilibrium of selenium dioxide to be removed from water
leaving a solid percipitate of selenium dioxide with sulfuric and phosphoric acid the adding magnesium sulfate to percipitate out magnesium phosphate
leaving behind sulfuric acid with manganese sulfate impurity which hopefully could be used in repeating this process.
Any mistakes are these reactions possible before i have a go on it.
Nvm
http://www.bromicacid.com/lonelychemist/Questions/062308.htm
Found the link
[Edited on 6-7-2018 by symboom]
unionised - 6-7-2018 at 01:32
I'm fairly sure that selenium dioxide is volatile enough that it will distil over with the nitric acid.
I also think that you won't precipitate magnesium phosphate in strongly acid conditions.
You are certainly not going to get manganese sulphate.
symboom - 6-7-2018 at 11:15
I thought magnesium phosphate is insouble in almost everything thats the only way that would proceed
Selenium dioxide boiling point
315°C
Phosphoric acid boiling point
158°C
Nitric acid boiling point
83°C
Looked it up
Selenium dioxide and phosphoric acid was lower than i thought
Fractional distillation
[Edited on 6-7-2018 by symboom]
CobaltChloride - 6-7-2018 at 11:46
Fractional distillation will not work. That boiling point for H3PO4 you have there is actually the temperature at which 85% H3PO4 starts to lose
water. H3PO4 doesn't have a boiling point per se; if you heat it up it will gradually lose water making polyphosphoric acids and eventually
metaphosphoric acid. You might be able to distill the HNO3 and SeO2 if you are courageous enough to heat glassware containing highly toxic selenium to
315 degrees, but be aware that hot phosphoric acid damages glass (see this thread http://www.sciencemadness.org/talk/viewthread.php?tid=78495 )
symboom - 6-7-2018 at 11:58
I found a better method i could add sulfur dioxide which will reduce the seleous acid and nitric acid to selenium and nitrogen dioxide gas that could
be lead into hydeogen peroxide to form back nitric acid the solution would contain sulfuric acid and selenium along with phosphoric acid
[Edited on 6-7-2018 by symboom]
[Edited on 6-7-2018 by symboom]