Ill probably get burnt for this but..........................
the fire depressant is (in my experience) just as soluble as the sodium chlorate but not as hydrascopic so...
If you add a large amount of the mixture to water gradually at first it all disolves then as more and more is added crystals refuse to dissolve. Keep adding the mixture untill a large amount of the crystals are refusing to dissolve.
Importaintly some of the crystals that will sit at the bottom of the container will be as large as the ones you first added.
Keep shaking the container regulally making sure it doesnt get warmer as this will affect the solubility of the different chemicals. (I work at room temp)
Eventually there will be a lot of very fine white crystals in the water and an amount of seemingly untouched crystals at the bottom of the container (I use a pop bottle so its watertight and clear to see the contents)
let the crystals settle and carefully pour off the liquid through a coffee filter and evaporate the water off.
This works as the sodium chlorate is more hydroscopic than the dampener so it will steal the H2O from it making it recrystalise. but only when there is excess sodium chlorate in the container. Ie the untouched crystals in the base of the mix.
Pthis is intended as a "HOW TO" not a "GO DO IT"
be good
Does this work? using the hygroscopic nature of a salt to keep it in solution when
a salt of similar solubility crystalises out. It sounds like it should! If it does I might try
it just to see it in action. (I can always weed the paths with the result as its too
much trouble to dry and keep dry)
If you want to speed up the burning of Sodium Chlorate soaked paper add five percent
Pottassium Fericyanide to the solution.