Sciencemadness Discussion Board - Potassium Persulfate Oxidizer

Potassium Persulfate Oxidizer

atomicfire - 6-7-2011 at 05:02

Being the season of fireworks and explosives, seeing some got me thinking of some good old flash powder recipes.

I happen to have some potassium persulfate and I was wondering if this could be used in conjunction with Al powder to create the same effect as the other oxidizers do. I haven't seen much use of this one so I figured I'd ask.

quicksilver - 6-7-2011 at 06:00

It may have been more productive if you had searched first before starting the thread.
As I understand your query, you are wondering if potassium persulfate has the ability to release the same (or better oxygen levels, with the same speed, as other oxidizers within the class of materials utilized in various flash powders for "report compositions" with metallic fuels.
Please see:
http://www.sciencemadness.org/talk/viewthread.php?tid=14308#...

Yet there is a great deal more to what makes a oxidizer appropriate in a flash powder mixture. Some if the original materials were utilized specifically for their ability to be controlled in the original application wherein flash powder was designed for; that of making a brilliant light for indoor photography. The by-product of this agenda was a faster and faster ignition level, that eventually became so fast that it would "self contain" in a weight level wherein the ignition produced a report without containment. Where this composition WAS contained, it was ideal for entertainment pyrotechnics (& eventually a "flash-bang" design for military / law enforcement). With KClO4 that weight is generally 50gr.
So here you have a broader element of utility. Does it release O at the same of faster rate as some in common use? Does it release the same or greater O as those in common use? And finally can it be as controllable? These are a sampling of those questions that a comparison would begin to answer.

Indeed, there are more issues which would present themselves. Understanding what aspects of deflagerant design presents the concept of self containment would be one. As with self containment [for the ability] to move surrounding air would (in most cases) emit a report especially IF containment were a manageable thing. However what safety aspects would present themselves in moving from common oxidizers in report compositions? Why is it that some oxidizers are NOT commonly used; even though they have clearly provided a great deal of oxygen & at speed (such as KMnO4)?

See: Faith, Keyes, & Clark's Industrial Chemicals. Wiley-InterScience pp 679-683 4th ed, 1975. Rapid Guide to Chemical Incompatibilities Pohanish & Greene.

Let's always think through the queries and SEARCH prior to developing a new thread so that the questions are new to the Forum & develop some depth to our discussions.

[Edited on 6-7-2011 by quicksilver]

Oxidizers in general

The WiZard is In - 6-7-2011 at 08:33

AA Shidlovskiy
Principles of Pyrotechnics
1964

This from the American Fireworks News http://www.fireworksnews.com/ 3rd ed.

I would expand upon contain the maximum amount
of oxygen. Contain the maximum amount of usable
oxygen. Dichromates make lousy oxidizers.

franklyn - 6-7-2011 at 15:36

http://www.sciencemadness.org/talk/viewthread.php?tid=1778&a...

quicksilver - 6-7-2011 at 16:09

Indeed; "usable oxygen".... The Dichromates make sense on paper. I actually had forgotten about AFN (& I still subscribe).

Franklyn's thread WAS unique...... That was an old thread me thinks. Lots'a good stuff.

[Edited on 7-7-2011 by quicksilver]

The WiZard is In - 6-7-2011 at 17:22

Quote: Originally posted by quicksilver

Indeed; "usable oxygen".... The Dichromates make sense on paper. I actually had forgotten about AFN (& I still subscribe).

Dug this up out of la net as I cannot find it on my HD

K idchromate is not, however, used as an oxidizing agent despite
having an attracting 38% oxygen content.

The decomposition reaction as given by Takeo Shimizu shows why-

4 K2Cr2O7 --> 4 K2CrO4 + 2 Cr2O3 + 3 O2

A little quick math reveals that - 1177 grams of potassium
dichromate yield a miserly 48 grams of oxygen! (4% of starting
weight!) Thus potassium dichromate is a very weak (pyrotechnic)
oxidizer. Shimizu also notes; It is difficult to ignite or to explode a
mixture of potassium dichromate and red phosphors or sulphur
even by impact between iron surfaces.

Ammonium dichromate is a basket case oxidizer.

atomicfire - 6-7-2011 at 19:28

Thank you for the information, but I decided the best course of action was to experiment on my own.

I mixed an approx 60/40 ratio of the oxidizer and Al powder. The mixture was lit unconfined and burned fast with a bright white flash.

I'm sure the ratio isn't optimum but my original question was to see if it would even work, so I have answered that. Next I guess I want to see what happens when the mixture is confined to a paper tube.

AndersHoveland - 6-7-2011 at 22:36

Potassium persulfate is a worse oxidizer than potassium nitrate in pyrotechnics for several reasons.
Obviously you noticed that the formula K2S2O8 has eight oxygen atoms, which is much more than other typical oxidizers. Unfortunately, the sulfur-oxygen bonds are much stronger than nitrogen-oxygen or chlorine-oxygen. K2S2O8 will very easily give up one oxygen atom, but the remaining 7 do not really act like much of an oxidizer. In addition, notice that there are 2 useless potassium ions for every persulfate ion, whereas there is only 1 potassium ion for every perchlorate ion in KClO4. Persulfate is also a much more reactive oxidizer, potentially making compositions more dangerous and sensitive to ignition.

quicksilver - 7-7-2011 at 06:17

IIRC Potassium persulfate is commonly available as some pool or spa chemical. Like quite a few items it was a by-product of some manufacturing & re-sold at profit.

Those were both excellent points however:

"A little quick math reveals that - 1177 grams of potassium
dichromate yield a miserly 48 grams of oxygen! (4% of starting
weight!) Thus potassium dichromate is a very weak (pyrotechnic)
oxidizer. "

"Unfortunately, the sulfur-oxygen bonds are much stronger than nitrogen-oxygen or
chlorine-oxygen. K2S2O8 will very easily give up one oxygen atom, but the remaining 7
do not really act like much of an oxidizer. "

The Dichromates (more so, persulfate with EIGHT O atoms) certainly APPEAR like they would be a candidate but all I remember from decades past was the use of dichromates in protecting powdered Mg & those volcanoes that kids used to make for elementary school. I can't think of a sulfate (or persulfate) that IS a worthy contestant.
I didn't keep up with a flash discussion sometime back but was there an oxidizer that was remarkably more effective than permanganate? I believe the conclusion was that was pretty much the end of the line as reflected in utility, cost, safety (ha!), etc.

AndersHoveland - 7-7-2011 at 17:53

dichromates are feasible, if not ideal, oxidizers. K2Cr2O7 is a better oxidizer than K2S2O7, because although Cr bonds more strongly to oxygen, this is only the first three bonds; after that the additional oxygen bonds are weaker (technically the bond strengths are symmetric).

as can be seen in the comparison, dichromate easily relinquishes more oxygen than persulfate:
K2Cr2O7 --> K2O + Cr2O3 + (3)O
K2S2O7 --> K2S2O7 + O

Comparing oxygen released based on weight of oxidizer is problematic. Lead nitrate would not be much worse than zinc nitrate. It would be more useful to calculate specific heat of starting oxidizer and/or the byproducts.

there is also potassium ferrate (VI), K2FeO4, which one would think would be better than permanganate, as the iron will easily reduce to the +3 oxygen state, whereas the manganese will easily reduce to +4. (of course, both can reduce down to +2, but with somewhat more difficulty). Whereas permanganate makes for a messy oxidizer, leaving dark stains and potential ground pollution, the iron oxides formed from ferrate would be completely benign.

[Edited on 8-7-2011 by AndersHoveland]

woelen - 7-7-2011 at 22:51

Sometimes, sulfates are used as oxidizer. E.g. SrSO4 can be used in flash powders as the oxidizer. These flash powders are very hard to ignite, but once they are going, they go fast and release a lot of energy.

Sulfate has a lot of oxygen and although these oxygens are tightly bound to the sulphur and for all practical purposes the sulfate ion can be considered inert in almost all kinds of aqueous chemistry, at very high temperatures it can become reactive. Actually, a similar thing is true for perchlorate ion. This ion is remarkably inert in aqueous solution (even more so than sulfate to my personal experience), but in pyrotechnics it is used quite a lot. It reacts more easily than sulfate, but still, perchlorate based flash powders also are not that easy to ignite.

So, I can imagine that in flash compositions peroxodisulfates can perform well, but I do not know about their stability on storage. Persulfates are useless from a point of view of 'colder' pyrotechnics. E.g. black powder based on K2S2O8 does not work at all. It only fizzles/smoulders a little bit, nothing more. Persulfates (and consequently sulfates) ONLY work well in high-temperature environments. Flash powders (in general, metal powder based compositions) usually are.

[Edited on 8-7-11 by woelen]

The WiZard is In - 7-7-2011 at 22:59

Quote: Originally posted by woelen

Sulfate has a lot of oxygen and although these oxygens are tightly bound to the sulphur and for all practical purposes the sulfate ion can be considered inert in almost all kinds of aqueous chemistry, at very high temperatures it can become reactive. Actually, a similar thing is true for perchlorate ion. This ion is remarkably inert in aqueous solution (even more so than sulfate to my personal experience), but in pyrotechnics it is used quite a lot. It reacts more easily than sulfate, but still, perchlorate based flash powders also are not that easy to ignite.

Page 8 PGI Bulletin No. 46, March, 1985
THE FEW, THE PROUD, THE SULFATES
by
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 [1985]) 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.

atomicfire - 8-7-2011 at 06:38

Great Information. Thank You!

I was originally only interested in if this oxidizer would even work in such a mixture. I found that out easily. I realize that this is not an ideal mixture, but just because its not the best doesn't mean one can't experiment and explore its uses does it? That is all I am after.

AndersHoveland - 8-7-2011 at 18:02

Sulfates may be capable of acting as oxidizers when the fuel is a reactive metal powder (Al or Mg), but otherwise sulfates are useless as pyrotechnic oxidizers. Since most sulfates form hydrates, a large amount of heat is required to cause these hydrates to decompose. I have tried MgSO4*(7)H2O with magnesium powder, and it did not appear to be capable of burning, although I suspect thermite would have been capable of igniting a larger quantity of the composition, and there would probably be danger of explosion from all the hydrogen gas that would be produced.

FrankRizzo - 8-7-2011 at 19:53

Sometimes it's fun to be an armchair scientist, but it's more fun to get out and experiment!

Persulfate Flash powder test
http://www.youtube.com/watch?v=FiVYSsiod_E

MgSO4 Flash Powder Test
http://www.pyrobin.com/files/mgso4%20flash_divx.avi

[Edited on 7/9/2011 by FrankRizzo]

Blasty - 9-7-2011 at 05:19

Quote: Originally posted by FrankRizzo

Sometimes it's fun to be an armchair scientist, but it's more fun to get out and experiment!

Persulfate Flash powder test
http://www.youtube.com/watch?v=FiVYSsiod_E

MgSO4 Flash Powder Test
http://www.pyrobin.com/files/mgso4%20flash_divx.avi

[Edited on 7/9/2011 by FrankRizzo]

Nice flashes. These mixtures ought to give sharp reports if strongly confined, like the barium sulfate based mix does. Was any amount of sulfur used to attempt to lower the ignition point?

[Edited on 9-7-2011 by Blasty]

The WiZard is In - 9-7-2011 at 06:27

Quote: Originally posted by FrankRizzo

Sometimes it's fun to be an armchair scientist, but it's more fun to get out and experiment!

Persulfate Flash powder test
http://www.youtube.com/watch?v=FiVYSsiod_E

MgSO4 Flash Powder Test
http://www.pyrobin.com/files/mgso4%20flash_divx.avi

[Edited on 7/9/2011 by FrankRizzo]

Did you try the magnesium without the Per S?
Magnesium is very energetic on it own, perhaps
side-by-side.

djh
---
Above all, a knowledge of chemistry is
absolutely necessary, seeing that chemistry
which performs the function of combining
the materials which are used in fireworks
compositions. It is necessary to know the
relationships of materials, and their
properties and their costs, so that the
operations can be performed as safely
and as economically as possible.

Claude-Fortuné Ruggieri
Principles of Pyrotechnics
3rd Edition 1821
Translated by Stuart S Carlton
MP Associates 1994

watson.fawkes - 9-7-2011 at 06:57

Quote: Originally posted by The WiZard is In

As Dr. Conkling (in press [1985]) 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."

This is interesting. It would seem, then, that it's worth looking into using low-melting eutectic mixtures of salts. That could increase oxidizing power all by itself. A salt that isn't particular vigorous by itself but lowers melting point significantly could be a net gain.

franklyn - 9-7-2011 at 08:28

One can burn gypsum cement with elemental Flourine,
does this make sulfates a good fuel ?

Iron oxide similarly is an oxidizer if reacted with aluminum,
does this make it good rocket fuel ?

.

The WiZard is In - 9-7-2011 at 10:51

Quote: Originally posted by franklyn

One can burn gypsum cement with elemental Flourine,
does this make sulfates a good fuel ?

Iron oxide similarly is an oxidizer if reacted with aluminum,
does this make it good rocket fuel ?

.

Ahhh well rockets dobe all 'bout Isp... The oxidizer is only
along for the ride.

Gypsum go big time ... use water.

TABLE 4

LF2, FLOX and LO2, SPILL TESTS

Surface material Cloud or vapor, behavior Reaction
and wt in lb

10-lb LF2 Spills

Crushed limestone (411) Grayish cloud ascended at Sputtering
a low angle and yellow
flames

Dry sand (320) White cloud ascended at Bright flame
45o angle

Water-soaked sand (321) Light gray cloud Strong
ascended at 40o angle explosion

Lake water** (5 gal) White cloud ascended Loud, sharp
detonation

**5 pounds of LF2. used in test with lake water.
Apparatus damaged also.

Safety Planning For The Use Of Reactive Cryogens In large Volume
[Liquid fluorine - liquid oxygen rockets!!]
EE Harton Jr.

Prevention of And Protection Against Accidental Explosions of
Munitions, Fuels and Other Hazardous Mixtures
Annals of the New York Academy of Science
Volume 152, Art. 1 Pages 1-913 October, 28, 1968

---
Yet another Dumpster-diving trophy.

quicksilver - 9-7-2011 at 12:44

Check out the "Projects " section:

http://www.ahpra.org/complaintform.htm

Some of the high percentage metal fuels and liquid fuels performed very well.