Toxic fumes boiling KNO3 in water.

[linker33]

Are there any toxic fumes given off when KNO3 is desolved in water, and boiled out? I am using this method to break down the particle size, and I'm just concerned about the any vapors that it may be giving off.

[Greg O'Bryant]

Linker:

There is no easy way to answer your question. What determines if something is toxic (or not) depends on the dose and exposure rout. Even water can be toxic in high enough amounts. So to answer your question Yes some KNO3 is probably getting into the air and you are inhaling it. However your body has a system specifically built to deal with nitrates and nitrites. So is the exposure ever going to get high enough to matter? I am not saying that it can't happen, but I have never heard of it. You would probably need to eat several spoons full of KNO3 to start doing damage.

PS does any body know what the LD/50 is for KNO3?

[Dang911]

Its releasing nitrogen and oxygen. Those are fine to breathe as that's mostly what our air is. The problem is in many instances it will also produce nitrogen oxides, N2O (laughing gas) but more potent, NO nitric oxide and NO2, nitrogen dioxide which are very harmful. As long as you keep a little ventilation you should be fine. I refine nitrate salts all the time by dissolving them in water and then re-crystallizing them or precipitating them out.

[Dang911]

Oh and I would like to mention that these results are much more likely to take place by boiling the kno3 itself, at its boiling point. Just boiling a an aqueous solution of it, will yield barely any of the effects I spoke of above, so don't be too concerned, just don't snuff the vapor.

[marksteamnz]

Are there any toxic fumes given off when KNO3 is dissolved in water, and boiled out? I am using this method to break down the particle size, and I'm just concerned about the any vapors that it may be giving off.

NO as long as you are drying the KNO3, no fumes can possibly be generated.
If it is a contaminated solution ALL BETS ARE OFF!
The melting point of pure KNO3 is over 300 degress Centigrade. Boiling point and decomposition temp is 400 degrees Centigrade.

Repeating what I have posted before. Type the chemical name into google with MSDS added (Material Safety Data Sheet) and the information will be there. True information not fevered imaginings.

[Mark]

When I was about 12, I bought 3 fifty pound bags of KNO3 from a fertilizer company. Way back then, it was pretty cheap. To powder it I put a funnel on one side of a motor such as this and a double pillow case on the out side. After running the prills through the impellor blades of the motor twice, the potassium nitrate came out like talc. The motor was fun just to hold and feel the force if you tried to tilt it. And it would make a neat sound as the blower spooled up.
Mark
http://tinyurl.com/ygpbsv

[linker33]

Thanks for the replies. Boiling it out worked great, and gave me a very fine consistancy. This mixes with the suger much better, and gives a much faster burning propellent.

[thecheat]

Well, I tried the boiling method. I was very pleasantly surprised of how well the propellant worked! My last batch used some not-so-finely-ground KNO3, and gave a nice somewhat forceful burst of smoke. The color was a light brownish orange.

With the boiling method however, though I can't say anything for the tedious length of boiling the water out, when I finished, the propellant was a light tan. When I lit it off on the pavement, not only did I recieve a LARGE cloud of smoke, but, the lump of propellant was moving itself around!

PS: the propellant all burnt in about five seconds. It weighed 125g total.

[Dang911]

Just a tip, after dissolving all of the kno3 in boiling water, spread it out on a metal sheet and throw it on the grill. It will take 1/10 the time to evaporate of the water, due to greater heat and surface area. Then just scrape off the powder into a container.

[thecheat]

hmm... now, wouldn't that be a fire hazard? Or, wouldn't that caramelize the sugar? I know when I just let the water boil out in the pot, then, let the sugar melt I got a nice propellant color. Would re-heating cause you to have the normal caramel color?

[Dang911]

Who the hell said anything about sugar? This topic is strictly for the refinement of kno3!

And if there was sugar, the described method above would be considered the re-crystallization propellant method, just not in an oven.

[thecheat]

oops... sorry, I think I interpreted you wrong... OK thanks for pointing that out!

Please excuse the mistake!

Now, a question that's on the topic... wouldn't you have a solid layer of saltpetre left on the sheet? It seems that apparently you don't, but, I'm just wondering about this, as, it would be a much easier method then grinding up this stuff by hand!

[Dang911]

You have to agitate it whiles your evaporating off the water. Its the same as doing it in a cup, just more surface area for a quicker refine. Grinding it up also works, but you are breaking apart the particles. When you refine it, each small granule was formed and is complete crystal structure (nicely aligned), so a slightly better oxidizer results.