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Author: Subject: Paraffin + KClO3 : SLOW reaction: why ?
metalresearcher
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[*] posted on 9-3-2018 at 12:29
Paraffin + KClO3 : SLOW reaction: why ?


Unlike sugar or other organic combustibles, paraffin (candle wax) reacts barely with KClO3.
I used a 'waxine light' (a thin aluminum container of 4cm diameter with wax in it, most is already used, so only for 1/4 filled and added a teaspoon of KClO3 to it. I heated it in a steel can and it took about four minutes (speeded up 8x in the video) until it ignited. That appeared like is was just without the KClO3.
I filmed with the GoPro Hero 5 pasted on the outside of the fume hood window with 240 fps.

Finally a lousy (compared to the mixture with sugar) reaction occurred which I also show with 1/15 speed.

https://www.metallab.net/jwplayer/video.php?v=L2NsaXBzL1Bhcm...

Why do such 'oily / waxy' substances react so slowly with KClO3 ?

[Edited on 2018-3-9 by metalresearcher]




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Σldritch
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[*] posted on 9-3-2018 at 13:27


This is typical behavior of Nitrates/Chlorates/Perchlorates.

They need nonvolatile fuels like carbon or a compound that decomposes to a nonvolatile fuel like carbohydrates. Volatiles like hydrocarbons or 1,2-dihydroxyethane/1,2,3-trihydroxypropane will not work. They evaporate and keep the temperature too low for the oxidizer to decompose and add to the combustion process. The combustion takes place above the mixture with air and not the solid oxidizer. The solid oxidizer can act as a wick and burn the fuel like a candle though.

Beware though, they will not burn vigorously but can still detonate. Probably not very sensitive though.

[Edited on 9-3-2018 by Σldritch]
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Vomaturge
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[*] posted on 9-3-2018 at 13:34


The wax melts, then boils or decomposes into flammable vapor, and then finally catches fire. When the wax is flaming, that is just the vapors burning. The liquid wax itself is not hot enough to react with the solid oxidizer

Eventually, the wax/chlorate mix gets hot enough to decompose the potassium chlorate into potassium chloride and oxygen. At that point you see the flame get hotter and brighter. Unfortunately, by that point, most of the wax has already vaporized and caught fire in the air above the KClO3.

With sugar, I think it's vaporization temperature is close to its ignition temperature. So it reacts with the chlorate as it burns.

Edit: Eldritch/ Sigma Ldritch beat me to it. He's got a good point about the detonation thing too. If one of these mixes does manage to start burning vigorously, the intense pressure of the combustion might stop the wax from boiling so easily. From there on, it can explode.

[Edited on 9-3-2018 by Vomaturge]
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ave369
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[*] posted on 9-3-2018 at 13:42


Try to detonate this thing. What you've made is fairly similar to cheddite, which is a mixture of KClO3 and various oily, waxy or greasy reducers.



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Antiswat
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[*] posted on 12-3-2018 at 04:12


i mean to say the poles used a mixture of KClO3 and parrafin wax in WWII as handgrenades in the range of 200 grammes
more interestingly: this mixture could be cast, 90:10?? the cast mix should be fairly acceptable to shockwaves, i recall something about diameter of these charges, something near 4:1 which could suggest the critical diameter isnt much of a problem
reference on this? many years since i came across this




~25 drops = 1mL @dH2O viscocity - STP
Truth is ever growing - but without context theres barely any such.

https://en.wikipedia.org/wiki/Solubility_table
http://www.trimen.pl/witek/calculators/stezenia.html
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