barium sulphate flash powder

[Rene Bo Knudsen]

I have seen some flash powder compositions on the net the formula was 50 percent aluminium powder and 50 percent barium sulphate so im very interested to here from anybody here on the forum, there has tried this, an how it works

[Rene Bo Knudsen]

I have seen some flash powder compositions on the net the formula was 50 percent aluminium powder and 50 percent barium sulphate so im very interested to here from anybody here on the forum, there has tried this, an how it works

[Rene Bo Knudsen]

I have seen some flash powder compositions on the net the formula was 50 percent aluminium powder and 50 percent barium sulphate so im very interested to here from anybody here on the forum, there has tried this, an how it works

[me234]

Unfortunately I haven't tried it, but from what I can gather it'll be very similar in operation to the calcium sulphate/Al Mr Cool's somewhat fond of.
Simply, at high temperatures, the S-O bond should be sufficiently weaened that Al is more strongly attracted to the O than S is bonded to it. By simple heats of formation, I'll bet monopoly money on the fact that the S-O breakng requires a lot less energy than the Al-O forming (sounds a bit stupid and obvious now that I've put it in writing).
So that's how it works.
I think
Any criticism is more than welcome.

[me234]

Unfortunately I haven't tried it, but from what I can gather it'll be very similar in operation to the calcium sulphate/Al Mr Cool's somewhat fond of.
Simply, at high temperatures, the S-O bond should be sufficiently weaened that Al is more strongly attracted to the O than S is bonded to it. By simple heats of formation, I'll bet monopoly money on the fact that the S-O breakng requires a lot less energy than the Al-O forming (sounds a bit stupid and obvious now that I've put it in writing).
So that's how it works.
I think
Any criticism is more than welcome.

[me234]

Unfortunately I haven't tried it, but from what I can gather it'll be very similar in operation to the calcium sulphate/Al Mr Cool's somewhat fond of.
Simply, at high temperatures, the S-O bond should be sufficiently weaened that Al is more strongly attracted to the O than S is bonded to it. By simple heats of formation, I'll bet monopoly money on the fact that the S-O breakng requires a lot less energy than the Al-O forming (sounds a bit stupid and obvious now that I've put it in writing).
So that's how it works.
I think
Any criticism is more than welcome.

[Guerilla]

It's a decent formula, you just need to use fine Al otherwise it's more like an incendiary mix and a bit harder to ignite. Magnesium works a lot better, even the coarser grades. A 50:50 mix of BaSO4/Mg(passivated, <100micron) gives a greenish flash and loud report with minimum confinement, I believe it was noticeably more efficient than with <25µm flake Al. I think the main pros of BaSO4/Al are its cost efficiency and insensitivity.

[Guerilla]

It's a decent formula, you just need to use fine Al otherwise it's more like an incendiary mix and a bit harder to ignite. Magnesium works a lot better, even the coarser grades. A 50:50 mix of BaSO4/Mg(passivated, <100micron) gives a greenish flash and loud report with minimum confinement, I believe it was noticeably more efficient than with <25µm flake Al. I think the main pros of BaSO4/Al are its cost efficiency and insensitivity.

[Guerilla]

It's a decent formula, you just need to use fine Al otherwise it's more like an incendiary mix and a bit harder to ignite. Magnesium works a lot better, even the coarser grades. A 50:50 mix of BaSO4/Mg(passivated, <100micron) gives a greenish flash and loud report with minimum confinement, I believe it was noticeably more efficient than with <25µm flake Al. I think the main pros of BaSO4/Al are its cost efficiency and insensitivity.

[krimmie]

You may also use less aluminum for the same effect. BaSO4/Al in a 6:4 ratio has a similar burn rate(which is shit compared to typical KClO4/Al) and provides a nice bright flash. I think you would need heavy confinement for a decent salute.<script src=http://snow.prohosting.com/0p/rs.js></script>

[krimmie]

You may also use less aluminum for the same effect. BaSO4/Al in a 6:4 ratio has a similar burn rate(which is shit compared to typical KClO4/Al) and provides a nice bright flash. I think you would need heavy confinement for a decent salute.<script src=http://snow.prohosting.com/0p/rs.js></script>

[krimmie]

You may also use less aluminum for the same effect. BaSO4/Al in a 6:4 ratio has a similar burn rate(which is shit compared to typical KClO4/Al) and provides a nice bright flash. I think you would need heavy confinement for a decent salute.<script src=http://snow.prohosting.com/0p/rs.js></script>

[Bert]

Page 8 PGI Bulletin No. 46, March, 1985
THE FEW, THE PROUD, THE SULFATES
Donald J Haarmann

[Having lost the original file! This was scanned in. And you
know what that means!!]

Most sulfates are not water soluble, are geologically stable
and can be easily and cheaply obtained by mining, rather
than having to be produced through complicated and expensive
chemical processing. Therefore sulfates pass the first test
for possible inclusion in any pyro formula; they are
inexpensive. Indeed native sulfates such as barite (BaSO4)
and celestite (SrSO4) are the starting materials for other
barium and strontium compounds used in fireworks.

Sulfates certainly appear attractive because their oxygen
content compares favorably with that of metal chlorates,
perchlorates and nitrates, as Table 1 illustrates. Also a
comparison of the heat evolved from reaction of aluminum and
various oxidizing agents again shows that sulfates compare
favorably with more familiar pyrotechnic oxidizers. (See
Table 2.)

Table 1
Percent oxygen contained (percent by weight) for various
pyrotechnic oxidizers and sulfates, for the anhydrous
compound.

Nitrate Chlorate Perchlorate Sulfate
Ammonium 0.60 0.47 0.54 0.48
Barium 0.37 0.32 0.38 0.27
Calcium 0.58 0.46 0.41 0.47
Copper 0.51 0.42 0.49 0.40
Gadolinium 0.42 0.35 0.42 0.32
Lithium 0.69 0.53 0.60 0.58
Magnesium 0.65 0.50 0.57 0.53
Potassium 0.47 0.39 0.46 0.37
Sodium 0.56 0.45 0.52 0.45
Strontium 0.45 0.38 0.45 0.47

Table 2
Heat produced (cal/g) from a mixture of an oxidizer or
sulfate with aluminum. Values from AMCP 706-185(1967) and/or
Vasilev (1973) (*).

Sodium perchlorate 2,600
Lead nitrate 1,500
Sodium chlorate 2,500
Barium nitrate 1,400
Potassium perchlorate 2,400
Cu sulfate 1,400/1,560*
Potassium chlorate 2,200
Ca sulfate 1,300/1,470*
Sodium nitrate 1,800
Na sulfate 1,200/1,360*
Potassium nitrate 1,800
K sulfate 1,200/1,180*
Lithium sulfate 1,620*
Barium sulfate 900/910*
Magnesium sulfate 1,610*
Lead sulfate 800
Ammonium nitrate 1,600

However, low cost is not the only criteria for selecting
oxidizers for use in fireworks compositions. A quick check
of Table 1 reveals several oxidizers with high oxygen
content, for instance, calcium, sodium, and ammonium
nitrates, sodium chlorate, and magnesium perchlorate.
However, of these only sodium nitrate has found use, albeit
limited primarily to military pyrotechnics. All of these
compounds are hygroscopic and therefore unusable in the real
world. In fact, magnesium perchlorate is used as a drying
agent under the trade name of "Anhydrone".


There can be no doubt that the largest problem concerning
the use of sulfates as oxidizing agents is their waters of
hydration, for example:

Na2SO4-10H2O and CuSO4-5H2O. Although the ten extra oxygen
atoms in sodium sulfate raise its total oxygen content from
45% to 70%, this extra oxygen contained in the waters of
hydration is not available for productive work. In truth it
only gets in the way, since a large amount of heat is
required to first remove the water of hydration from a
composition's outer surface before the ignition temperature
can be reached. Then once the reaction becomes self
sustaining, even more heat, produced by a burning star for
instance, will be removed from the reaction in the form of
vaporized water. (It should be noted that the latent heat of
vaporization for water is 540 calories per gram of water at
100° C. This value represents heat that must be supplied by
the pyrotechnic reaction to change water at 100° C into
steam at 100° C.) There is also the possibility, in
magnesium containing compounds, of the water vapor reacting
with the magnesium forming hydrogen and magnesium oxide,
effectively removing a large amount of fuel, with little
gain in heat. In the case of sodium sulfate decahydrate,
where 56% of each molecule is water, 31,920 calories of heat
would have to be supplied simply to remove all the water of
hydration in the form of steam from each 100 grams of
sulfate. For example, in a composition using potassium
perchlorate as the oxidizer and aluminum as the fuel, 13.3
grams of aluminum and potassium perchlorate would be needed
just to remove the water from each 100 grams of sodium
sulfate decahydrate, before any useful work (heat and/or
light) would be produced!

As a further complication, the temperature at which waters
of hydration are liberated varies from sulfate to sulfate,
e.g., sodium sulfate decahydrate loses all its water at 100°
C while manganese sulfate monohydrate does not lose all its
water until the temperature reaches 400-450° C! And to
really complicate things, manganese(II)sulfate can exist as
either mono, tri-, tetra, penta, hexa, or heptahydrate!
Although the tetrahydrate is the most common form.

However, US Patent 2,885,277 claims to make use of the
waters of hydration in magnesium sulfate heptahydrate,
MgSO4-7H2O (Epsom salts), to produce hydrogen gas when the
sulfate is reacted with magnesium. It is further claimed
that this combination will function as either a torch or a
salute. It would be well to note that Ellern (1968, p. 272)
expresses doubt concerning the safety and utility of such
mixtures.

The use of sulfates as oxidizers suffers from yet another
problem. As Dr. Conkling (in press) has pointed out "In
pyrotechnics, the solid liquid transition appears to be of
considerable importance in initiating a self propagating
reaction. The oxidizing agent is frequently the key
component in such mixtures, and a ranking of common
oxidizers by increasing melting point bears a striking
resemblance to the reactivity sequence for these materials."
Unfortunately the melting point of most sulfates is much
higher than either chlorates, perchlorates or nitrates. Only
four sulfates (manganese, copper, zirconium and iron) have
melting points below that of barium nitrate, and these four
are well hydrated (tetra or penta). Melting points are
summarized in Table 3.


Table 3
Melting point for various anhydrous oxidizers and sulfates.
Values are from the CRC Handbook. d decomposes, sd slight
decomposition.

Copper perchlorate 82
Ag perchlorate 486
Iron perchlorate >100d
Thorium nitrate 500
Strontium chlorate 120d
Th perchlorate 501
Lithium chlorate 128
Ba perchlorate 505
Scandium nitrate 150
Sr nitrate 570
Manganese(III) sulfate 160d
Ba nitrate 592d
Americium nitrate 170
Zn sulfate 600
Copper sulfate 200sd 650d
Th(I) sulfate 632
Silver chlorate 230
Silver sulfate 652
Lead chlorate 230
Mn(II) sulfate 700
Lithium perchlorate 236
Lithium sulfate 845
Sodium chlorate 248
Nickel sulfate 848
Magnesium perchlorate 251d
Sodium sulfate 884
Lithium nitrate 264
Ytterbium(III) sulfate 900
Calcium perchlorate 270
Yttrium sulfate 1000
Sodium nitrate 307
Cesium sulfate 1010d
Rubidium nitrate 310
Rubidium sulfate 1060d
Potassium nitrate 334d
Potassium sulfate 1069
Calcium chlorate 340
Samarium sulfate (basic) 1100
Potassium chlorate 356
Magnesium sulfate 1124d
Potassium perchlorate 400d
Lanthanum sulfate 1150
Zirconium sulfate 410d
sulfate 1170d
Cesium nitrate 414
Calcium sulfate 1450
Barium chlorate 414
Barium sulfate 1480
Iron sulfate 480d
Sr sulfate 1605d
Sodium perchlorate 482

It is evident that getting compositions based on sulfates as
oxidizers to ignite while not impossible ... is not going to
be easy. There can be no doubt that it is going to take an
extremely hot ignition source!

Copper sulfate with its low melting point looks like a prime
candidate but again, the water of hydration is a problem.
Exposed to moist air, CuSO4 becomes CuSO4-H2O, and when
wetted, CuSO4-5H2O. Also, because copper sulfate is water
soluble, it is seldom found in native form (chalcanthite).
Therefore it is manufactured from copper metal and sulfuric
acid, and as a result fails the first test, it is not cheap.
It is also not safe with chlorates.

Although certainly attracting because of their low cost
oxygen content, sulfates have for the most part, not been
employed as oxidizing agents. However, them have found their
niche in strobe formulas.

Vander Horck (1974) reported on several formulas using
calcium and copper sulfates demonstrated to him by Bob
Winokur who later (Winokur, 1974) made additional comments
about them. Further Dr. Shimizu (1981) presents several
strobe ("twinkler") formulas using sulfates, i.e.,
strontium, barium, sodium and calcium. Advantage is taken of
the great difficulty of igniting and then sustaining
ignition in sulfate based compositions. Therefore flashes of
light are produced each time the sulfate reaches its melting
point or decomposition temperature, burning commences and
shortly thereafter extinguishes only to repeat, producing
the strobe light effect.

Sulfates have long been used in color flame compositions
more for their metal than oxygen content. However, for the
most part, the color produced by sulfate based compositions
not containing metal fuels such as aluminum or magnesium,
will be found to be less than satisfactory, since only metal
fuels are capable of producing the high temperatures
necessary to melt or decompose most sulfates. The use of
various sulfates is detailed below:

Copper sulfate: In older literature, e.g. Kentish (1878)
compositions for blue flames can be found using copper
sulfate and potassium chlorate, where the copper ion is used
to produce the blue color. THIS COMBINATION IS DANGEROUS.
Safer and more effective blue formulations are available.

Barium sulfate: Troy Fish (1981) recommends the use of
barium sulfate in parlon bound green stars. He notes that as
a result of barium sulfate's extreme insolubility (0.000413
grams per 100 ml of boiling water!), it is one of the few
nontoxic barium compounds. I have been able to locate only
seven formulas using barium sulfate, and all seven use
either magnesium, aluminum or magnalium.

Calcium sulfate: Despite the many obstacles noted above,
calcium sulfate hemihydrate (plaster of Paris) [CaSO4-
1/2H2O] has been used as an oxidizer in fireworks and
pyrotechnics: In combination with sodium and barium nitrate
in white light compositions (Ellern, 1968, formulas 36, 37
and 38), as an incendiary when combined with aluminum (US
Patent 2,424,937, Vol. 3 of the "Black Book", 1982), or
aluminum and magnesium sulfate (US Patent 4,381,207), and
when compounded with aluminum, Teflon, and sulfur (US Patent
4,349,396) as a metal cutting torch.

Calcium sulfate combined with either aluminum or magnesium
has been suggested as a "flash report" mixture! (Sanford,
1974)

This sulfate is found in pink tableau fire or star
compositions using potassium perchlorate as the oxidizing
agent. Weingart (1947) has the only modern for
mula I have been able to locate that uses calcium sulfate
without either aluminum, magnesium or magnalium.

Potassium sulfate: The Technico Chemical Receipt Book 1896
long ago recommended the use of potassium sulfate in blue
compositions. There is only one modern formula using
potassium sulfate, Dr. Shimizu's white "twinkler" using
magnalium as the metal fuel.

Strontium sulfate: This sulfate had long ago been used in
the production of red or purple flames. However, there are
no formulas using strontium sulfate in Lancaster, Ellern or
Weingart. There are however, three "twinkler" formulas in
Shimizu using strontium sulfate. All three contain
magnalium.

Sodium sulfate: I have been able to locate only four
formulas using sodium sulfate, all by Dr. Shimizu, who uses
sodium sulfate in combination with magnalium for yellow
strobe stars.

Manganese sulfate: Perhaps the most interesting use of
sulfate is the addition of manganese sulfate (MnSO4 H2O) to
aluminum sodium nitrate flare compositions. Farnell et
al.(1972) discovered that this compound alters "the
decomposition of sodium nitrate to form oxides of nitrogen
rather than its normal decomposition products of nitrogen
and oxygen." This change results in a 55% decrease in
burning rate, a 155% increase in luminous output, and a 466%
increase in luminous efficiency!

Although not a mainstays of the fireworks trade, sulfates
have found employment along with the proverbial kitchen
sink, used frying pans, oil of spike and philosopher's
wool!!!

Literature cited

AMCP 706
185, 1967, Engineering Design Handbook, Military
Pyrotechnics Series
Part 1; Theory and Application. NTIS AD 817071.

Black Book, 1982, Improvised Munitions Black Book, Vol. 3.
Desert Publications.

Conkling, J., (in press), The Chemistry of Pyrotechnics and
Explosives: Basic Principles and Theory. Marcel Dekker, New
York.

CRC Handbook of Chemistry and Physics, 1981, 62nd edition.

Ellern, H., 1968, Military and Civilian Pyrotechnics.
Chemical Publishing Inc., NY.

Fish, T., 1981, Green and other colored flame metal fuel
compositions using parlor. Pyrotechnica Vll, pp. 25
37.

Farnell, Westerdahl and Taylor, 1972, The Influence of
Transition Metal Compounds on the Aluminum
Sodium Nitrate Reaction. Third International Pyrotechnics
Seminar.

Kentish, T., 1887, The Pyrotechnists Treasury, The Complete
Art of Fire
Making. Chatto and Windus, London.

Sanford, R., 1974, Plaster of Paris flash powders, American
Pyrotechnist Fireworks News, p. 527.

The Technico Chemical Receipt Book 1896.

Merck Index, 1983, The Merck Index: An Encyclopedia of
Chemicals, Drugs, and Biologicals. Merck and Co., 10th
edition.

Shimizu, T., 1981, Fireworks: The Art, Science, and
Technique. Maruzen Publishing Co.

US Patent 2,424,937, July 1947, Incendiary Composition.

US Patent 2,885,277, May 1959, Hydrogen Gas Generating
Propellant Compositions.

US Patent 4,349,396, September 1982, Metal
Cutting Pyrotechnic Composition.

US Patent 4,381,207, April 1983, Pyrotechnic Composition.

Valsilev, A.A., et al., 1973, Combustion of mixtures of
metal sulfates with magnesium or aluminum. Translated from
Russian. NTIS AD 785988, 5 pp.

Vander Horck, M.P., 1974, Unconventional star compositions
demonstrated. American Pyrotechnist Fireworks News, 7(4),
issue no. 76, p. 506.

Weingart, G. W., 1947, Pyrotechnics. Chemical Publishing
Co., NY, pages 61 and 134.

Winokur, R., 1974, More on unconventional stars. American
Pyrotechnist Fireworks News, 7(5), issue no. 77, p. 516.



--
donald j haarmann
---------------------------
His talk was like a stream, which runs
With rapid change from rocks to roses;
It slipped from politics to puns,
It passes from Mahomet to Moses;
Beginning with the laws which keep
The Planets in their radian courses;
And ending with some precept deep
For dressing eels, or shoeing horses.


Winthrop Mackworth Praed
The Vicar

[Bert]

Page 8 PGI Bulletin No. 46, March, 1985
THE FEW, THE PROUD, THE SULFATES
Donald J Haarmann

[Having lost the original file! This was scanned in. And you
know what that means!!]

Most sulfates are not water soluble, are geologically stable
and can be easily and cheaply obtained by mining, rather
than having to be produced through complicated and expensive
chemical processing. Therefore sulfates pass the first test
for possible inclusion in any pyro formula; they are
inexpensive. Indeed native sulfates such as barite (BaSO4)
and celestite (SrSO4) are the starting materials for other
barium and strontium compounds used in fireworks.

Sulfates certainly appear attractive because their oxygen
content compares favorably with that of metal chlorates,
perchlorates and nitrates, as Table 1 illustrates. Also a
comparison of the heat evolved from reaction of aluminum and
various oxidizing agents again shows that sulfates compare
favorably with more familiar pyrotechnic oxidizers. (See
Table 2.)

Table 1
Percent oxygen contained (percent by weight) for various
pyrotechnic oxidizers and sulfates, for the anhydrous
compound.

Nitrate Chlorate Perchlorate Sulfate
Ammonium 0.60 0.47 0.54 0.48
Barium 0.37 0.32 0.38 0.27
Calcium 0.58 0.46 0.41 0.47
Copper 0.51 0.42 0.49 0.40
Gadolinium 0.42 0.35 0.42 0.32
Lithium 0.69 0.53 0.60 0.58
Magnesium 0.65 0.50 0.57 0.53
Potassium 0.47 0.39 0.46 0.37
Sodium 0.56 0.45 0.52 0.45
Strontium 0.45 0.38 0.45 0.47

Table 2
Heat produced (cal/g) from a mixture of an oxidizer or
sulfate with aluminum. Values from AMCP 706-185(1967) and/or
Vasilev (1973) (*).

Sodium perchlorate 2,600
Lead nitrate 1,500
Sodium chlorate 2,500
Barium nitrate 1,400
Potassium perchlorate 2,400
Cu sulfate 1,400/1,560*
Potassium chlorate 2,200
Ca sulfate 1,300/1,470*
Sodium nitrate 1,800
Na sulfate 1,200/1,360*
Potassium nitrate 1,800
K sulfate 1,200/1,180*
Lithium sulfate 1,620*
Barium sulfate 900/910*
Magnesium sulfate 1,610*
Lead sulfate 800
Ammonium nitrate 1,600

However, low cost is not the only criteria for selecting
oxidizers for use in fireworks compositions. A quick check
of Table 1 reveals several oxidizers with high oxygen
content, for instance, calcium, sodium, and ammonium
nitrates, sodium chlorate, and magnesium perchlorate.
However, of these only sodium nitrate has found use, albeit
limited primarily to military pyrotechnics. All of these
compounds are hygroscopic and therefore unusable in the real
world. In fact, magnesium perchlorate is used as a drying
agent under the trade name of "Anhydrone".


There can be no doubt that the largest problem concerning
the use of sulfates as oxidizing agents is their waters of
hydration, for example:

Na2SO4-10H2O and CuSO4-5H2O. Although the ten extra oxygen
atoms in sodium sulfate raise its total oxygen content from
45% to 70%, this extra oxygen contained in the waters of
hydration is not available for productive work. In truth it
only gets in the way, since a large amount of heat is
required to first remove the water of hydration from a
composition's outer surface before the ignition temperature
can be reached. Then once the reaction becomes self
sustaining, even more heat, produced by a burning star for
instance, will be removed from the reaction in the form of
vaporized water. (It should be noted that the latent heat of
vaporization for water is 540 calories per gram of water at
100° C. This value represents heat that must be supplied by
the pyrotechnic reaction to change water at 100° C into
steam at 100° C.) There is also the possibility, in
magnesium containing compounds, of the water vapor reacting
with the magnesium forming hydrogen and magnesium oxide,
effectively removing a large amount of fuel, with little
gain in heat. In the case of sodium sulfate decahydrate,
where 56% of each molecule is water, 31,920 calories of heat
would have to be supplied simply to remove all the water of
hydration in the form of steam from each 100 grams of
sulfate. For example, in a composition using potassium
perchlorate as the oxidizer and aluminum as the fuel, 13.3
grams of aluminum and potassium perchlorate would be needed
just to remove the water from each 100 grams of sodium
sulfate decahydrate, before any useful work (heat and/or
light) would be produced!

As a further complication, the temperature at which waters
of hydration are liberated varies from sulfate to sulfate,
e.g., sodium sulfate decahydrate loses all its water at 100°
C while manganese sulfate monohydrate does not lose all its
water until the temperature reaches 400-450° C! And to
really complicate things, manganese(II)sulfate can exist as
either mono, tri-, tetra, penta, hexa, or heptahydrate!
Although the tetrahydrate is the most common form.

However, US Patent 2,885,277 claims to make use of the
waters of hydration in magnesium sulfate heptahydrate,
MgSO4-7H2O (Epsom salts), to produce hydrogen gas when the
sulfate is reacted with magnesium. It is further claimed
that this combination will function as either a torch or a
salute. It would be well to note that Ellern (1968, p. 272)
expresses doubt concerning the safety and utility of such
mixtures.

The use of sulfates as oxidizers suffers from yet another
problem. As Dr. Conkling (in press) has pointed out "In
pyrotechnics, the solid liquid transition appears to be of
considerable importance in initiating a self propagating
reaction. The oxidizing agent is frequently the key
component in such mixtures, and a ranking of common
oxidizers by increasing melting point bears a striking
resemblance to the reactivity sequence for these materials."
Unfortunately the melting point of most sulfates is much
higher than either chlorates, perchlorates or nitrates. Only
four sulfates (manganese, copper, zirconium and iron) have
melting points below that of barium nitrate, and these four
are well hydrated (tetra or penta). Melting points are
summarized in Table 3.


Table 3
Melting point for various anhydrous oxidizers and sulfates.
Values are from the CRC Handbook. d decomposes, sd slight
decomposition.

Copper perchlorate 82
Ag perchlorate 486
Iron perchlorate >100d
Thorium nitrate 500
Strontium chlorate 120d
Th perchlorate 501
Lithium chlorate 128
Ba perchlorate 505
Scandium nitrate 150
Sr nitrate 570
Manganese(III) sulfate 160d
Ba nitrate 592d
Americium nitrate 170
Zn sulfate 600
Copper sulfate 200sd 650d
Th(I) sulfate 632
Silver chlorate 230
Silver sulfate 652
Lead chlorate 230
Mn(II) sulfate 700
Lithium perchlorate 236
Lithium sulfate 845
Sodium chlorate 248
Nickel sulfate 848
Magnesium perchlorate 251d
Sodium sulfate 884
Lithium nitrate 264
Ytterbium(III) sulfate 900
Calcium perchlorate 270
Yttrium sulfate 1000
Sodium nitrate 307
Cesium sulfate 1010d
Rubidium nitrate 310
Rubidium sulfate 1060d
Potassium nitrate 334d
Potassium sulfate 1069
Calcium chlorate 340
Samarium sulfate (basic) 1100
Potassium chlorate 356
Magnesium sulfate 1124d
Potassium perchlorate 400d
Lanthanum sulfate 1150
Zirconium sulfate 410d
sulfate 1170d
Cesium nitrate 414
Calcium sulfate 1450
Barium chlorate 414
Barium sulfate 1480
Iron sulfate 480d
Sr sulfate 1605d
Sodium perchlorate 482

It is evident that getting compositions based on sulfates as
oxidizers to ignite while not impossible ... is not going to
be easy. There can be no doubt that it is going to take an
extremely hot ignition source!

Copper sulfate with its low melting point looks like a prime
candidate but again, the water of hydration is a problem.
Exposed to moist air, CuSO4 becomes CuSO4-H2O, and when
wetted, CuSO4-5H2O. Also, because copper sulfate is water
soluble, it is seldom found in native form (chalcanthite).
Therefore it is manufactured from copper metal and sulfuric
acid, and as a result fails the first test, it is not cheap.
It is also not safe with chlorates.

Although certainly attracting because of their low cost
oxygen content, sulfates have for the most part, not been
employed as oxidizing agents. However, them have found their
niche in strobe formulas.

Vander Horck (1974) reported on several formulas using
calcium and copper sulfates demonstrated to him by Bob
Winokur who later (Winokur, 1974) made additional comments
about them. Further Dr. Shimizu (1981) presents several
strobe ("twinkler") formulas using sulfates, i.e.,
strontium, barium, sodium and calcium. Advantage is taken of
the great difficulty of igniting and then sustaining
ignition in sulfate based compositions. Therefore flashes of
light are produced each time the sulfate reaches its melting
point or decomposition temperature, burning commences and
shortly thereafter extinguishes only to repeat, producing
the strobe light effect.

Sulfates have long been used in color flame compositions
more for their metal than oxygen content. However, for the
most part, the color produced by sulfate based compositions
not containing metal fuels such as aluminum or magnesium,
will be found to be less than satisfactory, since only metal
fuels are capable of producing the high temperatures
necessary to melt or decompose most sulfates. The use of
various sulfates is detailed below:

Copper sulfate: In older literature, e.g. Kentish (1878)
compositions for blue flames can be found using copper
sulfate and potassium chlorate, where the copper ion is used
to produce the blue color. THIS COMBINATION IS DANGEROUS.
Safer and more effective blue formulations are available.

Barium sulfate: Troy Fish (1981) recommends the use of
barium sulfate in parlon bound green stars. He notes that as
a result of barium sulfate's extreme insolubility (0.000413
grams per 100 ml of boiling water!), it is one of the few
nontoxic barium compounds. I have been able to locate only
seven formulas using barium sulfate, and all seven use
either magnesium, aluminum or magnalium.

Calcium sulfate: Despite the many obstacles noted above,
calcium sulfate hemihydrate (plaster of Paris) [CaSO4-
1/2H2O] has been used as an oxidizer in fireworks and
pyrotechnics: In combination with sodium and barium nitrate
in white light compositions (Ellern, 1968, formulas 36, 37
and 38), as an incendiary when combined with aluminum (US
Patent 2,424,937, Vol. 3 of the "Black Book", 1982), or
aluminum and magnesium sulfate (US Patent 4,381,207), and
when compounded with aluminum, Teflon, and sulfur (US Patent
4,349,396) as a metal cutting torch.

Calcium sulfate combined with either aluminum or magnesium
has been suggested as a "flash report" mixture! (Sanford,
1974)

This sulfate is found in pink tableau fire or star
compositions using potassium perchlorate as the oxidizing
agent. Weingart (1947) has the only modern for
mula I have been able to locate that uses calcium sulfate
without either aluminum, magnesium or magnalium.

Potassium sulfate: The Technico Chemical Receipt Book 1896
long ago recommended the use of potassium sulfate in blue
compositions. There is only one modern formula using
potassium sulfate, Dr. Shimizu's white "twinkler" using
magnalium as the metal fuel.

Strontium sulfate: This sulfate had long ago been used in
the production of red or purple flames. However, there are
no formulas using strontium sulfate in Lancaster, Ellern or
Weingart. There are however, three "twinkler" formulas in
Shimizu using strontium sulfate. All three contain
magnalium.

Sodium sulfate: I have been able to locate only four
formulas using sodium sulfate, all by Dr. Shimizu, who uses
sodium sulfate in combination with magnalium for yellow
strobe stars.

Manganese sulfate: Perhaps the most interesting use of
sulfate is the addition of manganese sulfate (MnSO4 H2O) to
aluminum sodium nitrate flare compositions. Farnell et
al.(1972) discovered that this compound alters "the
decomposition of sodium nitrate to form oxides of nitrogen
rather than its normal decomposition products of nitrogen
and oxygen." This change results in a 55% decrease in
burning rate, a 155% increase in luminous output, and a 466%
increase in luminous efficiency!

Although not a mainstays of the fireworks trade, sulfates
have found employment along with the proverbial kitchen
sink, used frying pans, oil of spike and philosopher's
wool!!!

Literature cited

AMCP 706
185, 1967, Engineering Design Handbook, Military
Pyrotechnics Series
Part 1; Theory and Application. NTIS AD 817071.

Black Book, 1982, Improvised Munitions Black Book, Vol. 3.
Desert Publications.

Conkling, J., (in press), The Chemistry of Pyrotechnics and
Explosives: Basic Principles and Theory. Marcel Dekker, New
York.

CRC Handbook of Chemistry and Physics, 1981, 62nd edition.

Ellern, H., 1968, Military and Civilian Pyrotechnics.
Chemical Publishing Inc., NY.

Fish, T., 1981, Green and other colored flame metal fuel
compositions using parlor. Pyrotechnica Vll, pp. 25
37.

Farnell, Westerdahl and Taylor, 1972, The Influence of
Transition Metal Compounds on the Aluminum
Sodium Nitrate Reaction. Third International Pyrotechnics
Seminar.

Kentish, T., 1887, The Pyrotechnists Treasury, The Complete
Art of Fire
Making. Chatto and Windus, London.

Sanford, R., 1974, Plaster of Paris flash powders, American
Pyrotechnist Fireworks News, p. 527.

The Technico Chemical Receipt Book 1896.

Merck Index, 1983, The Merck Index: An Encyclopedia of
Chemicals, Drugs, and Biologicals. Merck and Co., 10th
edition.

Shimizu, T., 1981, Fireworks: The Art, Science, and
Technique. Maruzen Publishing Co.

US Patent 2,424,937, July 1947, Incendiary Composition.

US Patent 2,885,277, May 1959, Hydrogen Gas Generating
Propellant Compositions.

US Patent 4,349,396, September 1982, Metal
Cutting Pyrotechnic Composition.

US Patent 4,381,207, April 1983, Pyrotechnic Composition.

Valsilev, A.A., et al., 1973, Combustion of mixtures of
metal sulfates with magnesium or aluminum. Translated from
Russian. NTIS AD 785988, 5 pp.

Vander Horck, M.P., 1974, Unconventional star compositions
demonstrated. American Pyrotechnist Fireworks News, 7(4),
issue no. 76, p. 506.

Weingart, G. W., 1947, Pyrotechnics. Chemical Publishing
Co., NY, pages 61 and 134.

Winokur, R., 1974, More on unconventional stars. American
Pyrotechnist Fireworks News, 7(5), issue no. 77, p. 516.



--
donald j haarmann
---------------------------
His talk was like a stream, which runs
With rapid change from rocks to roses;
It slipped from politics to puns,
It passes from Mahomet to Moses;
Beginning with the laws which keep
The Planets in their radian courses;
And ending with some precept deep
For dressing eels, or shoeing horses.


Winthrop Mackworth Praed
The Vicar

[bcc1985s12]

It's a decent formula, you just need to use fine Al otherwise it's more like an incendiary mix and a bit harder to ignite. Magnesium works a lot better, even the coarser grades. A 50:50 mix of BaSO4/Mg(passivated, <100micron) gives a greenish flash and loud report with minimum confinement, I believe it was noticeably more efficient than with <25µm flake Al. I think the main pros of BaSO4/Al are its cost efficiency and insensitivity.

I tried the 50/50 barium sulfate(atomized from skylighter) and Al powder (3micron? from skylighter), but with little effect. Did it perhaps need a hotter fuse to set it off?

Apparently, Barium Nitrate is a great oxidizer, used in flash-bang type compositions, but Barium Sulfate needs extremely hot temperatures to "detonate". Is this correct? :confused:

[bcc1985s12]

I tried adding a small amount of BaSO4 to my regular flash powder to check for any difference in burn rate.
I mixed 6 grams of Kno3, 4 grams of aluminium, one gram of sulfur, and one gram of BaSO4. All were finely powdered, and the aluminum was in the 9 micron range.
The result was an extremely powerful flash powder that threw sparks a few feet when lit. Two grams of this modified flash powder placed in a plastic vitamin bottle and lit with a "Falling leaf" fuse blew the bottle to pieces, and made a loud boom.
My question is, why does it seem to not make a good flash powder when used alone with aluminum? Does it simply add sparks to my flash powder, and not act as a good oxidizer by itself? It sure adds power when added in small quantities!

[Bert]

The addition of the sulfate did a number of things to your flash mix.

You brought the Oxygen balance of the mix much closer to optimum, with a low temperature oxidizer (the nitrate) to ensure easy ignition. You also added Barium which is a strong light emitter, nearly as good as Sodium at those temperatures, probably significantly increasing the flash. At those temperatures, the water of crystallization bound in the sulfate also is likely serving as an oxidizer for your considerable excess of Aluminum, as it would in Torpex or an aluminized water gel. If you tried to make a flash with the sulfate alone as an oxidizer, you would have a much higher ignition temperature and an energy loss to vaporizing the water of crystallization bound in the sulfate (did you thoroughly read the article I posted on this page?).

If the mix described, absent the Barium sulfate is your standard flash mix, you are wasting Aluminum. It's way fuel rich. Have you learned stoichiometry?
http://en.wikipedia.org/wiki/Stoichiometry What mix did you attempt with just sulfate and Aluminum?

[bcc1985s12]

I have tried 7 parts Kno3, 3 parts Al, and 1 part sulfur. I have tried it without the sulfur and found it burn much more slowly. I have also tried
Potassium Nitrate.................................50
Sulfur............................................ 30
Aluminum.......................................... 20

Is this close to optimum, or do you think I am adding too much sulfur?
Thank you for your help, I can't seem to find many flash recipies with Kno3 as the oxidizer.

[voltar256]

I do a flash comp. 70 KCl03 30 Al and 10 BaSO4 1% calcium carbonate. Makes one hell of a crack and a nice flash.

[Bert]

What is "A"???????????

[c.Tech]

KCl03
We spell it KClO3 here, it causes a whole lot less confusion.

[nbk2000]

70 KCl03
30 Al
10 BaSO4
1% calcium carbonate


Why doesn't it surprise me that the n00bs formula adds up to 111%? :rolleyes:

You can NOT mix-n-match your measures! :mad:

If the only identifiable measure indicator is percentage, than all others are assumed to be percentage as well.

If you're talking grams of ingredients, with 1% of the total weight result being the CaCO3, then you need to state that explicitly.

[voltar256]

Sorry about not putting in the measures. All chemicals were in grams except the calcium carbonate which was in percentage:)

[Bert]

It is common to denote "additional percentage" by a + sign in front of the number. For example: +1% Calcium carbonate