AndersHoveland
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Registered: 2-3-2011
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pyrotechnics: different types of green
The left column shows boron, the middle column shows copper salts, and the last column shows barium chlorate.
Barium nitrate by itself barely gives any green color, it is mostly white. I have tried this. There must be chloride ions also present, for example if
potassium perchlorate is added to the composition, if vinyl chloride is added, or if just some barium chloride is added to a regular composition. But
the best salts are barium chlorate or perchlorate.
There are different ways to give pyrotechnic compositions a distinctive green color when burning. Each has its own distinct advantages and
disadvantages.
Copper salts do not give a very distinctive green (it is more of a bluish white), and the intensity of the color is not very strong. When copper is
used, the green color is easily drowned out, or masked, by any other colors.
All three of these chemicals are fairly expensive for large scale use, which may be one of the reasons that green is not a very common color in
pyrotechnics.
[Edited on 21-4-2012 by AndersHoveland]
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albqbrian
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For composite rocket propellant...
I've had great luck with BaNO3 in APCP composites. I use 35% BaNO3, about 55% AP, and 4 or 5% Mg, and 1 or 2% FeO as the solids part.
It gives the greenest flame I've seen in this stuff. Plus it ignites easily and has plenty of oomph.
Great stuff.
On a somewhat related theme. For red flames I've found SrCO3 works far better than SrNO3. I use 8 or 9% SrCO3 along with the Mg and FeO. This gives a
super red flame. It is a bit difficult to ignite. And for whatever reason it is really tough on the phenolic, Aerotech type nozzles. Several years
back i made the LDRS video with an M motor I made with the SrCO3. It was red! But it also cracked the nozzle perfectly in half. Which led to the
rocket doing two or three, under full power, 360's before experiencing premature earth interaction  I talked to Gary, the owner of Aerotech, after
the flight. He said that they had also found that SrCO3 was tough on nozzles. But man does it look great. I'll just have to get better nozzles. Or
better yet, no nozzle at all. I plan on doing some concentrated research on that topic. I see no reason why nozzleless motors won't work in the High
Power rocketry realm. And boy would that simplify stuff. But that's for another day.
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Eddygp
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Location: University of York, UK
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Mix powdered magnesium, common salt (NaCl) and barium nitrate: this mix gives an intense white-green flame.
[Edited on 1-5-2012 by Eddygp]
there may be bugs in gfind
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