HNO3 with NaHSO4+KNO3

[inferno]

"..David pulverized the ores with a hammer, thinking that he could then use nitric acid to isolate uranium. Unable to find a commercial source for nitric acid--probably because it is used in the manufacture of explosives and thus is tightly controlled--David made his own by heating saltpeter and sodium bisulfate, then bubbling the gas that was released through a container of water, producing nitric acid..."

That last part is what im looking at. Would this work? This is taken from an article in the Miscellaneous forum about a 17 year old who made his own nuclear reactor in his back yard.

Anyway, its easier for me to get those two chems than to get nitric acid, what i imagined was putting the chems in a stopped flask with a piece of hose going up into an elevated container of water, and heating the flask either with a flame or placing it in boiling water.

I first assumed that the NO₃ ion joined the H in the water and made the acid, but after a little more research, im assuming the NaHSO₄ is evolved to HNO3, leaving maybe sodium and potassium sulphate. The vapours must form into the liquid in the water, which would probably have to be an ice bath to give instant cooling to the vapour.

And one more question, a 1% solution of sodium bisulphate in water has pH 1.3. Could it be used as a catalyst for AP?
Any help would be appreciated.

<small>[ June 02, 2002, 06:39 AM: Message edited by: inferno ]</small>

[Mr Cool]

NaHSO4 + KNO3 will not be a good way to make HNO3 for RDX or PETN. This is because you will have to get it very hot for it to react (probably a few hundred *C), and the HNO3 will therefore decompose when formed into NO2, O2 and H2O. This will form an equilibrium with HNO3 (more HNO3 at low temperatures since the decomposition of HNO3 is endothermic), but it will not totally re-react. Therefore, the HNO3 formed will contain a lot of NO2, and a lot of H2O. Both are bad.

[DBSP]

I'm not shure about this method it sound kinda wierd. If it would work would the reaction look something like this?:
NaHSO4 + KNO3 ---> HNO3 + NaSO4- + K+. Or would the K+ ion liberate the Na+ thus giving (KSO4-) + Na+

It all seemes wrong, but I don't know!

[Pu239 Stuchtiger]

NaHSO4 + KNO3 --> NaKSO4 + HNO3
4HNO3 + heat --> 2H2O + 4NO2 + O2

[inferno]

This is what i would do:
<pre>
______
/.-----.\
// \\
// | |||
|| | ||| H2O
|| ¯¯¯
/__\
/____\
KNO3+NaHSO4
</pre>
The KNO3+NaHSO4 would be heated, possibly in a slightly aqueous solution to help the reaction. The H₂O would be in an ice bath, or maybe straight into an ice bath, so hopefully the vapours would condense upon entering the water. I dont have any proper glassware so itd be a pretty simple setup.

What i want to know is if this would work, Pu's reaction looks about right, thanks for any suggestions.

<small>[ June 03, 2002, 04:51 AM: Message edited by: inferno ]</small>

[rikkitikkitavi]

Why not

Ca(NO3)2(aq) + NaHSO4 (aq) => CaSO4(s) + HNO3(aq) + NaNO3(aq) ?

Probably easier to find Ca(NO3)2 and cheaper to.
Filter out the CaSO4 ,and simple distillation removes the HNO3
from the NaNO3. Some NaNO3 is probably preciptated to, since the HNO3 will "push" it out of solution.

4 HNO3 = 2H2O + 4 NO2 + O2 is a equilbirium. Condensing the H2O and simultaneously absorb the NO2 in the water would give HNO3 again.

3 NO2 + H2O => 2 HNO3 + NO (net reaction, many intermediate steps )

It is similar to the real industrial process of making HNO3 where NO2 is lead through large absorbing towers with packed columns . You probably need some sort of packed column so the gas/water mixture has a large cntact area to react on. Only bubbling NO2 through the water probably leads to to short contact time/to small contact area and exessive losses of NO2. Unless ypu lead the gases through repeteaded absorbing flasks.

Maybe some sort of recirculation of the condensed water/acid from the bottom to the top to, so you wont get a to diluted acid?

I could make a simple schematic, but I dont know how to attach pictures?

It is very difficult to say how good it will work, but it will work to some extent. It seems like a simple setup , so why dont give it a try? And please let us know :)

The absorbtions process slows down when the HNO3 concentration goes up to, this is why commercial HNO3 usually comes as 53 %. Stronger acids (up to 68 %) are made trough distillation, and above 68 % extractive distillation with H2SO4 or Mg(NO3)2. There is new processes developed where O2, NO2 and H2O is reacted at very high pressures , giving > 95 acid directly.

/rickard

/rickard

[DBSP]

When I heard NaHSO4 it sounded familiar, now I'vre found out why.
A while ago I found a bottle of NaHSO4 prills at home, used for some toilet washing. And I have 24kg of Ca(NO3)2. I've been thinking about buying a dest. setup but I haven't been shure of that I could get enaugh sulfuric acid, now if this workes as well then I might buy one.

I'll try a small quantity and see if it colors my skin.

[DBSP]

I didn't make any calculations regarding this thing, I just took a pinch of NaHSO4 and a pinch of Ca(NO3)2 and poured it into a small ammount of water. When most of it had dissolved i poured some of it on a newspaper(this was yesterday). Today it had all dried out when I had a look at it. At the same time as I poured the mix onto the paper I allso poured a small ammount of water on the paper to have something to compare with. The paper was brown where the mix had been poured out and at the place the water had been poured there wasn't a trace left of it. The conclusion is that it workes, I wonder what conc you could get this to in the first step. That must depend on how much water is which is needed to dissolve the reactants. Calcium nitrate is very soluble in water but I haven't got any solubility data on the NaHSO4, has anyone got anything?

I haven't got merck installed right now since I formatted not so long ago, could anyone with it installed check that please.

If one would distill this mixture the HNO3 obtained would probably be low conc, perhaps 40-50%(has anyone any idea of conc? ).
After that it's easy to concentrate it the normal way. This method is perhaps more work demanding but worth it if it workes.

[rikkitikkitavi]

solubilty of NaHSO4 / 100 gr H2O

25 C 29 grams
100 C 49,7 grams

solubility of Ca(NO3)2 /100 gr H2O (
25 C 100 grams
100 C 354 grams


from my Lange, handbook of Chemistry

/rickard

[inferno]

Cool, it does work <img border="0" title="" alt="[Wink]" src="wink.gif" />

The way i was thinking though was to heat the NaHSO₄ and KNO₃, hopefully the resulting gases would condense when lead into an ice bath and form diluted HNO3, otherwise they could be lead into a salt-ice cooled closed flask to condense in there, but it would have to be closed or too much gas would be lost.