9 replies to this topic

[Gary]

Are the perchlorates of barium and strontium hardly ever used in pyrotechnics?
Do they have problems with hydroscopicity or stability?
By employing a perchlorate of barium ( for green) or strontium (for red), we have an oxidiser, chlorine donor and colour agent all originating from a single compound.
I could easily make these compounds......

[wjames]

i read something once about the space shuttle using strontium perchlorate for ptich and yaw control......injecting it in Aq format into the nozzle....

strontium perchlorate is used in flash powder, though i doubt anyone actaully uses the mix.....greenman lists it as TM1316 - 20 parts strontium perchlorate to 80 parts ( calcium/magnesium (75/25))

thats about the only thing i could find with a quick search.

Im sure there is someone on here with much more knowledge on those chemicals....

[digger]

Are the perchlorates of barium and strontium hardly ever used in pyrotechnics?
Do they have problems with hydroscopicity or stability?
By employing a perchlorate of barium ( for green) or strontium (for red), we have an oxidiser, chlorine donor and colour agent all originating from a single compound.
I could easily make these compounds......

I believe that both of these are deliquescent. So if you leave it out in the open you will return to a puddle of the salt in solution.

They do have applications in specialist pyrotechnics, but would be generally impractical in normal use.

Edited by digger, 14 November 2008 - 11:52 PM.

[wjames]

incidently, out of pure interest......care to share how you would make these ?????

[digger]

incidently, out of pure interest......care to share how you would make these ?????

I am not sure about the solubility table for strontium perc, but barium perc is far more soluble than sodium, potassium or ammonium perc (think about 3 times, over 600g per 100g of water near boiling point) hence double decomposition is out of the question.

So that leaves a couple of options.

1) Use barium or strontium hydroxide with ammonium perchlorate then drive off the ammonia by boiling.
2) Use perchloric acid with the carbonate, but as you will know perchloric acid can be bloody dangerous stuff for all sorts of reasons.

[T-sec]

Are n't they used in green and red flash salutes?

[digger]

Are n't they used in green and red flash salutes?

Well the formula posted above by WJames looks like a coloured salute formula.

I would assume that these are pretty specialist compositions requiring careful handling to keep them dry.

Have you seen the price of these chemicals off the shelf, ouch!

[Mortartube]

Out of interest. How much is Barium Perchlorate, as I have about 100g that I was given?

[pyrotrev]

Alkaline earth metal perchlorates are just about the most fiercely hygroscopic substances known - initially they were prepared for use as dessicants I believe. Some hang onto water so strongly that you can't remove all the water of crystallization by heating, it'll start to decompose first, which maybe explains why the anhydrous forms ain't exactly cheap. Also you need to be very careful when using them in the presence of alcohols and other organic solvents as they can produce some VERY dodgy reaction products.

Edited by pyrotrev, 17 November 2008 - 08:45 PM.

[Creepin_pyro]

An interesting thread here:

http://www.apcforum....s...0