| Pages:
1
2 |
nitro-genes
International Hazard
Posts: 1048
Registered: 5-4-2005
Member Is Offline
|
|
Yes, Mg is very reactive, even with potassium nitrate. I doubt you would be able to produce flash this fast with aluminium powder, even when nano
sized, could be wrong though.
|
|
|
ecos
Hazard to Others
Posts: 464
Registered: 6-3-2014
Member Is Offline
Mood: Learning !
|
|
Quote: Originally posted by deltaH  | I think some here are underestimating the power of nano-aluminium.
If you want to see just what these nanometals can do in combination with oxidants, see our very own dornier335a:
https://www.youtube.com/channel/UC6SItJwaTE3jawp-wGNKPBQ
Urea and pyroaluminium... ok
Urea and nanoaluminium... ehhh... maybe ok?
Peroxide or AN and nanoaluminium... BOOM!
[Edited on 11-11-2015 by deltaH] |
I don't agree with "AN and nanoaluminium... BOOM!" !!
it will never explode. AN need primer and it is insensitive.
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
NH4NO3 solution will chew through the Aluminium powder in less than a few days!
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
nitro-genes
International Hazard
Posts: 1048
Registered: 5-4-2005
Member Is Offline
|
|
yes, normally it would, I was thinking maybe in an W/O emulsion type propellant it may be more storage stable, then again...it is unlikely the nano Al
will only stay in the wax-dispersion phase. Another question is how fast the reduction of ammonium nitrate happens at -80 deg C or so, since we are
talking about (presumably) amorphously frozen propellants, hence <-80.
Another thought:
Magnesium powder can be coated with chromates to make it less prone to surface oxidation, similarly, IIRC, some chromates added to ammonium nitrate
solutions can strongly inhibit corrosion for several aluminium alloys.
A combination of these three factors may be enough to virtually eradicate the nitrate-Al problem.
|
|
|
ecos
Hazard to Others
Posts: 464
Registered: 6-3-2014
Member Is Offline
Mood: Learning !
|
|
I don't if Al would react with AN as you stated but I think under low temperature this reaction may stop. ALICE depends on low temp to stop the
reaction between water and Al.
I am not sure if Temp < -80 is logical. I thought about -10 degrees but not -80 
I have a question here , solution of Ammonium hydroxide ([NH4+][OH−]) would be much better than water since the earlier has Nitrogen and excess
hydrogen.
would that work ?
[Edited on 13-11-2015 by ecos]
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
| Quote: Originally posted by nitro-genes | yes, normally it would, I was thinking maybe in an W/O emulsion type propellant it may be more storage stable, then again...it is unlikely the nano Al
will only stay in the wax-dispersion phase. Another question is how fast the reduction of ammonium nitrate happens at -80 deg C or so, since we are
talking about (presumably) amorphously frozen propellants, hence <-80.
Another thought:
Magnesium powder can be coated with chromates to make it less prone to surface oxidation, similarly, IIRC, some chromates added to ammonium nitrate
solutions can strongly inhibit corrosion for several aluminium alloys.
A combination of these three factors may be enough to virtually eradicate the nitrate-Al problem. |
Chromates are activators for sensitization of NH4NO3...so a CATO (deflagration or detonation) of the propellant is to be expected.
Yeah nothing is that simple in chemistry  .
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
| Quote: Originally posted by ecos |
I don't if Al would react with AN as you stated but I think under low temperature this reaction may stop. ALICE depends on low temp to stop the
reaction between water and Al.
I am not sure if Temp < -80 is logical. I thought about -10 degrees but not -80
I have a question here , solution of Ammonium hydroxide ([NH4+][OH−]) would be much better than water since the earlier has Nitrogen and excess
hydrogen.
would that work ?
[Edited on 13-11-2015 by ecos] |
It is a strange effect of NH4(+) and NO3(-) on Aluminium...
Aluminium stands quite wel concentrated HNO3 because of Al2O3 protective oxyd layer but it doesn't stand wel concentrated NH4NO3 that is much less
ionic and acidic than HNO3...
True that maybe the lowering of the T° will reduce the corrosion speed sothat it becomes negligible.
But you are working with paradoxal aims...on one side nano aluminium to sensitize and increase efficiency by increasing the specific surface area and
at the same time reducing tendency to react (corrosion) by lowering the T°, waxing it or plating it with something to reduce its reactivity.
Working with NH4OH might be interesting indeed because at ambiant T° and pressure water can hold about 30% by weight of NH3, by lowering the T° you
can hold more NH3 per liter.
At -33,33°C pure NH3 is liquid so between 0 and -33°C you should be able to get the pure NH3.H2O (17g NH3 and 18g H2O or 48,57% NH3 by weight).
One last thing with Aluminium as propellant is the barrel and nozzle abrasion problem by Al2O3 (saphire with hardness 7 on Mohs scale) and AlN; but
also some of the solid aggregates as liquid glass and may stick to (or condense into) some parts of the nozzle (in the case of some incurvated nozzle
edges).
This might give troubles for reusable rockets.
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
ecos
Hazard to Others
Posts: 464
Registered: 6-3-2014
Member Is Offline
Mood: Learning !
|
|
I used to add 5% charcoal in ball mill to avoid oxidation of Al. Now I would run my ball mill for long time to prepare nano-Al.
would 5% charcoal be suitable to cover the nano-Al particles ?
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
| Quote: Originally posted by ecos |
I used to add 5% charcoal in ball mill to avoid oxidation of Al. Now I would run my ball mill for long time to prepare nano-Al.
would 5% charcoal be suitable to cover the nano-Al particles ? |
Who will cover who? C will coat the Al or Al will coat the C ...
If you go for nano...beware for the flash while opening the recipient to open air...specific surface become so big that FAE may occur...the Al powder
also becomes airborne and light entrapping much air inside...so in case of fire...hard to extinguish even with water (Al + H2O --> Al(OH)3 + Al2O3
+ Al(OH)O + H2)
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
ecos
Hazard to Others
Posts: 464
Registered: 6-3-2014
Member Is Offline
Mood: Learning !
|
|
I know that black powder Al is formed by having Al particles coated with C ! am I mistaken?
do I need to increase the ratio of C because I am planning to have smaller particles and this would mean more surface area needed to be coated?
Bert advised me before to open the Jar of milling every two days to avoid hazards
Do I need to use different coating material rather than C ?
what if fire happened ? how can i extinguish it ? i think i need to use sand !
[Edited on 23-12-2015 by ecos]
|
|
|
idrbur
Hazard to Self
Posts: 88
Registered: 23-6-2015
Member Is Offline
Mood: No Mood
|
|
Hi ecos,
If the aluminium reacts with ZnSO4.7H2O to give hydrogen than the reaction should also take place with CuSO4.5H2O /Al flash powder.
|
|
|
ecos
Hazard to Others
Posts: 464
Registered: 6-3-2014
Member Is Offline
Mood: Learning !
|
|
High water content would be better ... so ZnSO4.7H20 is better
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
