8. Commonly Used Chemicals in Pyrotechnics: C-D
Description
This article is from the Pyrotechnics FAQ, by Hans Josef Wagemueller zoz@cs.adelaide.edu.au with numerous contributions by others.
8. Commonly Used Chemicals in Pyrotechnics: C-D
Calcium carbonate, CaCO3 -- Stabilizer
Used as a neutralizer in mixtures that are sensitive to both acids and
bases, for example chlorate/aluminium flashpowder.
Calcium oxalate, CaC2O4 -- Colour Enhancer
Used to add depth to colours produced by other metal salts.
Carbon black/Lampblack, C -- Fuel
A very fine form of carbon made by incompletely burning hydrocarbon fuels.
Commonly used in gerbs to produce bright orange sparks.
Charcoal, C -- Fuel
Probably the most common fuel in firework manufacture, it is not pure
carbon and may contain in excess of 10% hydrocarbons. Indeed, the purer
carbon charcoals (e.g. activated charcoal) do not necessarily give better
results, and are very often worse than less pure grades. It is included
in the vast majority of pyrotechnic compositions in various mesh sizes
and grades, or as a component of black gunpowder.
Clay
This is an important material for making fireworks, not as a reagent but
to perform various practical applications such as blocking or constricting
the ends of tubes for crackers or rocket nozzles, or coating lead shot
prior to the application of star composition when making rolled stars.
Copper and copper compounds -- Colouring Agents
Used to add both green and blue colours to flames:
Copper metal, Cu -- Colouring Agent
Both the bronze and electrolytic forms are occasionally used, but easier
methods are available for the same effect.
Copper acetoarsenate, C4H6As6Cu4O16 -- Colouring Agent
Commonly called Paris Green, this chemical is toxic but used to produce
some of the best blue colours in combination with potassium perchlorate.
Copper carbonate, CuCO3 -- Colouring Agent
This is the best copper compound for use with ammonium perchlorate for
production of blue colours. Also used in other blue compositions.
Copper (I) chloride, CuCl -- Colouring Agent
Cuprous chloride is probably the best copper compound for creating blue
and turquoise flames, and it can be used with a variety of oxidizers.
It is non-hygroscopic and insoluble in water, but it is oxidised slowly
in air.
Copper oxides, CuO/Cu2O -- Colouring Agent
Used for many years for blues, but needed mercury chloride to intensify
colours. Seldom used.
Copper oxychloride -- Colouring Agent
Occasionally used in cheap blue compositions.
Cryolite, Na3AlF6 -- Colouring Agent
Also known as Greenland spar, this is an insoluble sodium salt. Sodium
salts are used to produce yellow colours, but as sodium salts generally
absorb water this tends to be a problem. By using cryolite this problem
is surmounted.
Dextrin -- Binder
Dextrin is a type of starch that is added to many firework mixtures to
hold the composition together. It is the most commonly used binder in
pyrotechnics.
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