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Boomer
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[*] posted on 14-12-2005 at 04:09


I could kick my own balls for letting the reaction conditions go astray :mad:
Yield of test No3 was 16.1g btw, which is 77%. Now does that mean that the addition of AN/UN did *decrease* yield? Or was it my 'fault' to let it react 4 min longer, and let it go up to 61C max instead of 55C, which turned out to be beneficial? Were those 10ml more nitric wasted in test No1 (only 1g more RDX for 15g more acid)? I am really angry at me! All I can do now is give more details:

- The reaction time after the last addition was chosen as 15 minutes for a reason in all three tests. This was the time an exotherm could be seen (rising from 15C to 26C and staying there in a 16C room), before it cooled down.

- In the third test, the heating time was 17 min instead of 12.5. Also the temp rose higher (61C instead of 55 like planned. The first time I had the thermometer in the water bath (55C), the second time I swapped it between the bath and the mix to find the mix approx 3C above the bath. It is a safe guess the bath was also at 58C in the first test. The last time the bath went to 58C, hence the high reaction temp. These deviations were caused by stupidly doing something else in parallel….

- The acid used must have been of better quality than usual. I recently went to distilling in three increments: From 400ml 96% SA and 400g AN the first 10ml are distilled off, receiver changed for a yield of 160ml of ‘the good stuff’, then 150g more An added and the old receiver put on again to use up all nitrate. Only the middle fraction was used for the RDX tests. No vacuum btw and 1-2 drops per second.

- Plus, in my older experiments I assume the HDN was not too good. In fact it had been stored at RT for some month and smelled of formaline. This, together with the better acid, must have been the reason for the good yields.

Unfortunately I am out of nitric again (60+50+50ml = 160ml duh). While I am happy with the results, they leave many questions open: Why no effect of the AN/UN? Would the first yield have been even better without? Why did 10ml more acid give only 1g more product? …

[Edited on 14-12-2005 by Boomer]

[Edited on 14-12-2005 by Boomer]
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[*] posted on 14-12-2005 at 10:04


Quote:
Originally posted by Boomer
I could kick my own balls for letting the reaction conditions go astray :mad:
Yield of test No3 was 16.1g btw, which is 77%. Now does that mean that the addition of AN/UN did *decrease* yield?


Yes , in the *lower ratios* of HNO3 to HDN ( having less acid in excess of theory for RDX ) the addition of salts can be counterproductive . For example if you took microteks 2:1
reaction system and added NH4NO3 and / or UN to it , the
yields might decrease substantially for that 2:1 reaction system . However , the efficency of your reaction #1 is
greater than microteks in terms of HDN conversion and very nearly as good in terms of absolute acid utilization efficiency . So there is no reason for you to be displeased with the result as it is likely nearer to a good general method which is more forgiving of small variables than
microteks method .

What I was saying earlier about predictability applies here
because microteks proportions are more susceptible to small variables . It would be more likely that ten different experiments with the 2:1 ratio would give ten different results , than a reaction system based on a 2.5:1 ratio .
The lower the ratio , the more chance the reaction will
fail to produce useful yields predictably from one experiment to the next under identical conditions . It is therefore desirable to give up a little in the area of absolute acid utilization efficiency , when the gain is in better predictabilty
and higher conversion for the HDN . Seeking maximum acid utilization efficiency also puts the reaction system right on the peak of a steep slope into diminishing yields if any of
several variables adversely affect the reaction . So a good general method will not seek some absolute maximum yield or efficiency at the expense of good reproducibility for a slightly lower yielding but much more reliable reaction .

If you were to graph the reaction efficiency for a good general method , there would be something more like a
plateau region on the graph describing the reaction mixture where good yields are obtained across a range including the point where yield is maximum , instead of a steep slope upwards to a sharp peak followed by another steep slope
downwards from that maximum . The graph having the
plateau region will describe a reaction which is less susceptible to variables .



Quote:

Or was it my 'fault' to let it react 4 min longer, and let it go up to 61C max instead of 55C, which turned out to be beneficial? Were those 10ml more nitric wasted in test No1 (only 1g more RDX for 15g more acid)?


Not really wasted in my opinion anyway . You are looking at absolute acid utilization efficiency as the goal with maximum yield of RDX in grams per ml of HNO3 , regardless of the conversion efficiency for the HDN and the reproducibility
which are also important factors . This sort of nitpicking
over the absolute acid utiliztion efficiency will likely never lead to a good efficiency good general method which is forgiving of small variables , and always gives acceptably good yields but at the slight expense of falling slightly short of maximum yields . It is something analogous to fine tuning a racing car to get an extra 10 miles an hour top speed above the 200 miles per hour it can do reliably all day without any problem , but the expense for that extra 10 is
that the engine might disintegrate on the first lap at the increased speed if the oil temperature is 5 degrees warmer .
The logic which applies to the analysis will determine which
implementation is superior for accomplishing a hundred laps reliably at 200 , or having bragging rights for one lap once in awhile at 210 :D

Quote:

I am really angry at me! All I can do now is give more details:

- The reaction time after the last addition was chosen as 15 minutes for a reason in all three tests. This was the time an exotherm could be seen (rising from 15C to 26C and staying there in a 16C room), before it cooled down.

- In the third test, the heating time was 17 min instead of 12.5. Also the temp rose higher (61C instead of 55 like planned. The first time I had the thermometer in the water bath (55C), the second time I swapped it between the bath and the mix to find the mix approx 3C above the bath. It is a safe guess the bath was also at 58C in the first test. The last time the bath went to 58C, hence the high reaction temp. These deviations were caused by stupidly doing something else in parallel….

- The acid used must have been of better quality than usual. I recently went to distilling in three increments: From 400ml 96% SA and 400g AN the first 10ml are distilled off, receiver changed for a yield of 160ml of ‘the good stuff’, then 150g more An added and the old receiver put on again to use up all nitrate. Only the middle fraction was used for the RDX tests. No vacuum btw and 1-2 drops per second.

- Plus, in my older experiments I assume the HDN was not too good. In fact it had been stored at RT for some month and smelled of formaline. This, together with the better acid, must have been the reason for the good yields.

Unfortunately I am out of nitric again (60+50+50ml = 160ml duh). While I am happy with the results, they leave many questions open: Why no effect of the AN/UN? Would the first yield have been even better without? Why did 10ml more acid give only 1g more product? …


Even better , don't be so picky about the acid quality , and
try an even more conservative 2.5:1 ratio for 3 experiments modeled on example #1 to see what is the reproducibility
and if yields will go even higher than 82% to maybe 88% based on HDN . If such an outcome occurs , then you will
pretty well have tagged the conditions for a general method .
I'll buy generalization and reproducibility with acceptably good yields at the expense of very little in terms of absolute
acid utilization efficiency , as a good bargain any day :D

You see that generalization will give you a " general recipe " that is guaranteed to work well every time , whereas nitpicking the conditions for absolute acid utilization efficiency will only identify an exceptional reaction condition where a maximum yield is obtained for very precise conditions that will likely be different by some variable that will have bearing when you try to repeat your own " maxed out " and " too refined " procedure . The next batch of distilled acid being different by even a fraction of a per cent ,
may be sufficient variable by itself to cause very different
results from what was carefully worked out before . But
a good general method is able to accommodate such variables without being adversely affected .
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[*] posted on 23-12-2005 at 10:38


Update: made another batch of nitric (250ml) and tried the first/last fraction for RDX. This is in colour between WFNA and RFNA, hence I call it WTFNA
(what-the-fuck nitric acid, i.e. I dont care). The *same* batch and bottle had given me 80% instead of 92% yield for MHN, and similar batches
preciously 30-40% only for RDX using the 1:2 ratio. And now comes the surprise:

7g of HDN where treated like above, using 21ml of the 'bad' acid, and letting it react for 20 min at 60 +/2 C. Result was 4.75g or 81%.
So a 1:3 ratio will forgive less-than-perfect nitric. It was dark yellow and had a density of 1.515 at -4C (or was it 0C? See above).
Makes d=1.48 at RT, from memory, is that 90% HNO3 considering the NOx content?

[Edited on 23-12-2005 by Boomer]
EDIT F*cking format to read, made it less wide

[Edited on 23-12-2005 by Boomer]
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[*] posted on 24-12-2005 at 16:17


Very interesting .

The data from experiments producing >80% yields of RDX
from the HDN , using 5% AN and 2.5% UN added to
the HNO3 of 97% down to 90% concentration , indicates
useful ratios of grams HDN to ml of HNO3 in the range of
1:2.4 for the 97% acid increasing to 1:3 for the 90% acid .

This is tracking nicely with my estimate of 1:2.5 as good for
the main distillation product HNO3 which is about 96.8% HNO3 . I think I will probably even nudge that ratio to 1:2.6 for my own future experiments , as a hopefully reliable " rule of thumb proportion " , forgiving of the variables which are sure to be present from batch to batch . These are still low acid ratios in comparison to most of the described industrial methods .
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[*] posted on 27-1-2006 at 10:11


Boomer, did you purify the acid after destilation?
You distil H2SO4 - NH4NO3, right?

Greetings for the good yield, I only get such with Merck acid - purged with oxygen for an hour.

[Edited on 27-1-2006 by simply RED]




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[*] posted on 30-1-2006 at 03:57


I tried purging with O2 from a bottle, but it was only slightly yellow anyway and did not get better by purging. Maybe I should have warmed it. And it was the middle fraction, the first and last few ml were collected separately. The first post on this püage tells proportions.

I am confused: Made two more batches, from a different batch each of NA and HDN. Yields were not consistent with last time, but consistently worse! 137ml nitric with 55g HDN gave 33g RDX, and 47ml with 19g gave 11.4g. That means 72% yield both times.

The first time I noticed lots of bubbling during the 15' at 55C, so I thouht it decomposed for some reason. So the second time I only warmed to 40C, but twice as long. Same result! I do admit the acid was month old, but stored in total darkness and below -15C. It was definitely better than the WTFNA from the test I did with the 'bad' fraction of acid. The HDN was also very dry, it lost less than 0.4% weight in a desiccator overnight. WTF went wrong? Not that 72% is thaaat bad, but still ...
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[*] posted on 30-1-2006 at 07:56


It is always very slightly yellow. Problems occure when it is dark red. Dark-red acid decomposes HDN on contact...

Homemade HNO3 in my experiments gave yields between 30% and 90% all times. Always irreproducible.
Very interesting - homemade fresh ditilled (at 100 deg C) HNO3 was usable for RDX without purification, while Merck "100%" was usable only after good purging.

Anyway, I never made acid enough pure to be used in dinitrourea synthesis. And start to think it is only possible in laboratory or at least well equipped garage.
Fumehood was the factor I missed...




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[*] posted on 14-1-2007 at 22:30
another possible nitrolysis catalyst / acid dehydration reagent


The wheels have been turning in old Rosco's head ,
wondering what value that bottle of Magnesium Oxide
sitting on the shelf in the health food store might be for
an off label use as a nitrolysis or nitration " enhancer " :D

And by golly it just could be a damn useful component
for reducing the water content in various processes
due to the high affinity for water of the nitrate of magnesium
which would form , at the expense of some of the acid
of course for forming that nitrate ......and I haven't run
the numbers on it yet , but it sure would seem to have promise of a net gain in that regard .

And it should be completely compatable with other additives
like urea nitrate or ammonium nitrate in the nitrolysis mixture
for conversion of HDN to RDX . This use of MgO added to
the acid mixture could also have value in many other nitration
mixtures where more radical dehydrating reagents have been found to be useful .

MgO + 2HNO3 ------> [ Mg(NO3)2 - 1 H2O ] mol.wt. 166.05

Added MgO will easily absorb 90% of its own weight of additional water beyond the monohydrate formation to form the trihydrate , and 180% of its weight to the pentahydrate .

MgO mol.wt. = 40.03
HNO3 mol.wt. = 63.01 ( X2 )

See the attached patent . In the patent process is
described the use of separately made Magnesium Nitrate
Trihydrate as a dehydrating agent ......and I am suggesting
even going beyond that and enhancing the dessicant effect
further by forming the nitrate in situ from the oxide .

If it is wished to make the magnesium monohydrate separately , so as to avoid any consumption of acid in its formation , simply long boiling of MgO with ammonium nitrate
to a cessation of evolution of ammonia should result in
a solution of Mg(NO3)2 . Heating this to dryness and then
to 330C produces the monohydrate .

Alternately , MgCO3 may be substituted in that boiling for
MgO . And if no source of MgO or MgCO3 is convenient ,
the MgCO3 can be precipitated from mixed hot solutions
of epsom salt and washing soda . So there are different
ways of obtaining / utilizing the Mg(NO3)2 monohydrate .

Another possible simple route to Mg(NO3)2 would be to
boil a mixture of Ca(OH)2 with mixed solutions of epsom salt and ammonium nitrate , until evolution of ammonia ceased ,
filter out the precipitated CaSO4 and concentrate the residual
solution of Mg(NO3)2 followed by dehydration by baking out the solids at 330C . But this strategy could be complicated by formation of double salts , so I am not certain this would work , but I think it likely would work .

[Edited on 15-1-2007 by Rosco Bodine]

Attachment: US5012019 Magnesium Oxide as Dehydrating Agent for HNO3.pdf (234kB)
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[*] posted on 15-1-2007 at 08:09


This is very fine indeed: a great find - as it seems applicable to so many things....to bad I have to work on MLK day. As this is something to test drive.
O.T question:
Do you think the acetonitrile / trioxane route is a no-go?




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[*] posted on 15-1-2007 at 09:21


Regarding the OT question ....I wouldn't necessarily call it a "no-go" , just not sure what is the real advantage if any .

Actually I think that triazone would be a higher priority
interest for investigation of possible RDX or keto-RDX ? precursor usefulness , if there were a list of favored
" experiments to do " as possible more efficient routes to RDX or equivalent analogues .

Didn't really give it much thought at the time or since , but
the triazone material did seem very interesting
when I came across it .

https://sciencemadness.org/talk/viewthread.php?tid=4812#pid5...

[Edited on 15-1-2007 by Rosco Bodine]
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[*] posted on 16-1-2007 at 07:42


I'm there - ....just as has been expressed before; my head (also) turns when seeing a flash of flesh from a promising looking girl and esoteric routes always intregue me as well. :D
The links were down to the posted material dealing w/ Ketone N so I couldn't read them but what I wonder is what is being done today: if the most efficient methods are not common knowlege re: RDX on lab scale (not industrial). I just can't see modern researchers still limited to mid-scale nitrations, etc. but I've been dead wrong before. Perhaps RDX is only produced on such a large scale that there has never been any need to move away from the simplier / direct methods of RDX production(?)...




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[*] posted on 16-1-2007 at 10:23


This idea of using Mg(NO3)2 monohydrate as a nitrolysis and/or nitration acid dehydrant ,
is very intriguing to me , more than any idea I have ever considered as having possible value in nitrations actually . It would be a totally OTC available route to providing a dehydrating reagent which just might be an acceptable substitute for much more exotic and expensive reagents
used for the same purpose ....like phosphorous pentoxide , or acetic anhydride , for dehydration of nitrolysis mixtures ....or in the place of oleum in nitration
mixtures . And of course there are also possibilities there for usefulness in the preparation of nitric acid
of high concentration .....prior to use in any nitration
where additional Mg(NO3)2 monohydrate could have further usefulness .

Having HNO3 of extremely high concentration at the beginning and maintaining the acid at a near to anhydrous condition during the nitrolysis or nitration is
a very important aspect of creating ideal conditions
with regards to the efficiency of the synthesis particularly
for RDX ....where even a 2 or 3 percent change in the
water content of the nitric acid can affect the yield by
twenty times that amount . So anything that gives even
a little improvement to the quality of the acid can have
a drastic influence on the efficiency of the reaction .

This could also apply as well to other nitrations which are
very sensitive to the water content of the acid or mixed acids ....where having anything present which can efficiently tie up indigenous or reaction byproduct water
will be likely to improve the yield considerably .

This Mg(NO3)2 idea is moving to the top of my
" must do experiments list " because of its potential
value in virtually any nitrolysis or nitration reactions .

There is not good information easy to find about the
different temperatures and hydration states for
Mg(NO3)2 , melting points for the various hydrates ,
and what is the decomposition temperature for the
monohydrate ....which I suppose is the lowest stable
hydrate . PATR references conversion of the hexahydrate
to the monohydrate at 330C , but I think
that is wrong . They are probably referencing the
trihydrate or possibly a dihydrate , as I would expect
a stepwise sort of dehydration passing through a series of distinct hydrates lower than the hexahydrate . So anyone having any extensive data on the hydration states for Mg(NO3)2 , please share a link or post the data here .

I found one reference in a patent that the hexahydrate of
magnesium nitrate melts in its own water of hydration at 90C .....which is a fairly high melting point for a hexahydrate and would account for a very absorptive and dehydrating activity towards formation of the hexahydrate at temperatures much lower than that 90C transition point ,
where a much lower than six hydrate is in the reaction system .

This is much higher activity than for example the tetrahydrate
of calcium nitrate which melts at ~42C .

If anybody has the book on Mg(NO3)2 ....I want it :D


[Edited on 16-1-2007 by Rosco Bodine]
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[*] posted on 16-1-2007 at 15:24


update

Evidently what I am thinking about the usefulness of
Mg(NO3)2 as a dehydrating agent in nitrations is not a new idea at all , because I have found a patent US2776965
(attached) for the manufacture of sulfoester free nitrocellulose , where no sulfuric acid at all is present in the nitration mixture , but magnesium nitrate is used in the place of sulfuric acid as a substitute dehydrating agent .

So the idea of using the Mg(NO3)2 as a dehydrating agent
definitely has validity already reported in a similar nitration
where sulfuric acid is not present ....but nitration is accomplished solely by concentrated nitric acid , and this
scenario is precisely the same as is the case for nitrolysis
of HDN to RDX , where sulfuric acid cannot be used anyway ,
and the efficiency of the nitrolysis is dependant upon the
hydration of the nitric acid being minimized ....which the
Mg(NO3)2 should accomplish .

The patent also mentions the preparation of the Mg(NO3)2
dehydrating reagent as a higher hydrate solution in water ,
and boiling it down to a lower hydrate syrup which is mixed
with nitric acid to form the nitrating mixture . One can reasonably expect that the syrup could be heated even further and dehydrated more fully near or all the way to the
monohydrate for even greater dehydrating effect . Granulation of the material solidified from a high temperature melt would probably require working out some special technique to keep the melt from setting up into a solid monolith on cooling . It might be as simple as stirring rapidly
with a glass rod as some alcohol is streamed on the hot material to hasten its cooling and evolve a blanket of alcohol vapor to keep air from overtly dampening the material .
Alternately , worse case scenario is that the melt could be poured over a pile of ceramic ball milling media in a bowl
or in the jar , and milled as it cools to break it up .

Additionally to the use of the Mg(NO3)2 in reactions which
are absent any sulfuric acid ......there seems to be no reason
why it would not also be useful in those other nitrations where sulfuric acid is used , as an additional dehydrating reagent which might substitute for free SO3 as would be
supplied by oleum .

Attachment: US2776965 Magnesium Nitrate used in Nitrocellulose Nitration.pdf (811kB)
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[*] posted on 18-1-2007 at 06:01


Quote:
Originally posted by Rosco Bodine
Actually I think that triazone would be a higher priority
interest for investigation of possible RDX or keto-RDX ? precursor usefulness , if there were a list of favored
" experiments to do " as possible more efficient routes to RDX or equivalent analogues .


Keto-RDX is a really interesting possibility indeed, having an even higher detonation pressure than HMX combined with good stability. The nitrolysis of triazones like TBT to yield keto-rdx seems to be extremely sensitive to the presence of any water. So regarding efficiency it can probably not rival the efficiency of HDN nitrolysis to produce RDX. IIRC, nitrolysis of TBT with anything else than 99% HNO3/AA or 99% HNO3/P2O5 resulted in almost insignificant low yields...

[Edited on 18-1-2007 by nitro-genes]
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[*] posted on 18-1-2007 at 09:58


From what I have seen in the patents concerning Mg(NO3)2
it does not exist *alone* as any lower hydrate than a monohydrate , but decomposes to nitrogen oxides and
magnesium oxide at 330C . Al(NO3)3 decomposes to its
oxide at a much lower 150C when it dehydrates completely . This decomposition property of hydrated alkaline earth nitrates is applied to a heat cured insulating foam ceramic material where a percentage of Mg(NO3)2 in the composition decomposes leaving micro bubble cavities in the ceramic and then the MgO decomposition product reacts at the high temperature with an acid phosphate or free phosphoric acid to form a magnesium phosphate binder which makes the foam set into a strong insulating refractory material . A mixture of the Mg(NO3)2 with Ca(NO3)2 is actually used in the material which is reportedly an excellent binder for perlite . See US4812170 .

Anyway , from the *all* references I have seen the presence of alkaline earth nitrates in anhydrous or near to anhydrous forms is more easily attained with double or mixed salts with two or more different nitrates . Zinc nitrate is mentioned as
forming a eutectic with Magnesium nitrate . Another aspect
of the anhydrous double salts which I have seen described is that they are pH dependant and stable only in alkaline condition , separating into a simple mixture when subjected to an acidic environment . This could be due to the presence of some trace or small percentage of the basic nitrate in an alkaline system , which acts to lower the melting point greatly , as there are many low melting point mixtures reported which involve a double salt of a normal nitrate with the basic nitrate which are anhydrous crystalline materials .

This interesting aspect about the double salts could possibly be exploited where the intent is to make use of the profound
dessicating capacity of the near to anhydrous salts , by formulating a mixed salt which is stably dehydratable on
heating to a lower temperature under the slightly alkaline
condition .....and drying it as much as possible by heating ,
pulverizing and then using it as a dessicant in a nitrating mixture . The acidity of the mixture would split the double
salt into a simple mixture of its nearly anhydrous constituents
with some small penalty for acid consumption in reacting
with the small percentage of the basic salt which is present .

This method has not been reported in the literature so far as I know it is just my theory that this strategy may work , as
an inference drawn from what is reported in references that I have seen .

A binary eutectic of Zinc Nitrate and Magnesium Nitrate was reported in one patent as useful for shifting the dehydration
temperature lower and away from the decomposition point
for the monohydrate of Mg(NO3)2 . See US5099078 .

And as a dehydrating reagent for the concentration of nitric acid , it is reportedly not necessary to do more than simply
use a ~70% solution , a liquid form of Mg(NO3)2 , present
in a bit more than equal portion by weight with 68% HNO3
in order break the azeotrope and to distill away >98% pure
HNO3 .....eliminating any formation of nitrosyl sulfuric acid
as occurs when H2SO4 is in contact with hot HNO3 .

Ca(NO3) is also reportedly useful for breaking the azeotrope
in distillation of HNO3 . See US864217 .

The inference which I am to a large extent presuming is
that in a nitration mixture itself , a more concentrated
acid is available also under the conditions of nitration as
a result of the same reagent as would break the azeotrope
during conditions of distillation .

So great is the affinity for water of the dehydrating salts
that they are useful even as their highly concentrated
solutions ......that is in liquid form . So it is intriguing
what possibility may exist for exploiting these nitrates
as desscicants in a nitrolysis mixture .

The aspect which lurks as a potential problem is that
the presence of the large concentration of the alkaline earth ion in the nitrolysis or nitration mixture might possibly
interfere with the nitration sufficiently to be conterproductive
and inhibit the desired formation of end product more than
would the presence of water in the absence of that ion .

So this is another one of those " bright ideas " which
could turn out to be only useful for distillations and
not useful at all for improving the conditions of nitration
itself . Even so , it would seem worth experimenting
to find out what the real deal is , since it is also possible
that the alkaline earth ion would simply be a spectator ion
and not interfere at all with the nitrolysis .....and could even be catalytic . Only experiments would reveal what is the true story on these things .

[Edited on 19-1-2007 by Rosco Bodine]

Attachment: US3173756 Magnesium Nitrate Ammonium Nitrate Anhydrous Double Salt.pdf (405kB)
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[*] posted on 22-1-2007 at 10:07


I found another patent US4316736 , from a different inventor that has a couple of lines which tends to confirm the anhydrous binary eutectic of NH4NO3 and Mg(NO3)2 reported in the patent just above , the higher NH4NO3 ratio to Mg(NO3)2 of 3:1 , which melts at 115C .....
see line 18 page 5 . This is the lower Mg(NO3)2 content
binary , which is a lower melting anhydrous intermediate ,
gradually converted upon introduction of increasing molar proportion of Mg(NO3)2 to a second higher melting
and also anhydrous equimolar eutectic of NH4NO3 and Mg(NO3)2 .......which is evidently a double salt also ,
NH4Mg(NO3)3 mp 167 .

The earlier patent US3173756 describes in example 1 ,
a laboratory scale preparation of the anhydrous binary eutectic , by way of a gradual addition in portions , of
MgO to molten NH4NO3 the time required being 3 to 4 hours for the additions , and the reaction mixture being
held at 200C .

I expect other approaches could also be used for this ,
which could be more efficient and also could be conducted
at a lower temperature . I also expect that this anhydrous eutectic could form as part of a more complex mixture which would remain anhydrous at a lower melt temperature in the presence of other materials which
are compatable . And I would further expect that certain
other materials added to such a melt , would be disruptive of the eutectic , and would cause crystallization
to some extent , facilitating granulation of the system
containing anhydrous Mg(NO3)2 .....either split away
from its double salt with NH4NO3 , or remaining combined
as such .

Possible materials which would seem likely candidates
for disrupting the equimolar anhydrous eutectic of
AN and MgN , and facilitating granulation , are an added
excess amount of MgO itself to cause some formation
of a basic magnesium nitrate salt as a contaminant ,
or possibly better to use a carbonate of magnesium
for this same purpose , the byproduct CO2 causing a
simulataneous foaming and solidification of the still
relatively anhydrous melt facilitating its granulation .

Ammonium pyrosulfate could have possible usefulness
as a disruptor and solidification , foaming and granulation
facilitator .

Al(NO3)3 which undergoes complete decomposition to
its oxide and nitrogen oxides at 150C could be a very effective reagent for foaming and disruption of the
binary eutectic which melts at 167C .

NaNO3 , KNO3 , urea , urea nitrate , are other possibilities .

Some mixture of these materials could be found to be
effective for preventing the NH4Mg(NO3)3 from setting
up as a monolith upon cooling of the melt ....but to
react with the added " granulating agent " in a way
which disrupts the dense melt , and provides a granular solid which yet retains its anhydrous or not greatly
diminished anhydrous properties .

If the solid material desired can be prepared by some scheme of this sort , then it should have value as a
dehydrating salt which can be added to nitration or
nitrolysis mixtures . And the material should also
have usefulness in concentrating nitric acid .

The Mg(NO3)2 content of the double salt could also be valuable for greatly increased yield of nitric acid , in synthesis where the nitrate is reacted with sulfuric acid and the nitric acid distilled .....
since there is no acid sulfate byproduct for the magnesium salt , then *both* hydrogens
of the sulfuric acid should participate in producing nitric acid , making it possible to theoretically obtain twice the amount of nitric acid from the same amount of sulfuric acid as would more commonly be gotten from reacting with a monovalent nitrate , which forms an acid sulfate niter cake byproduct .
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biggrin.gif posted on 31-8-2010 at 09:39
linkage with more recent thread


There is parallel interest with regards to the potential usefulness of nitrates having a dehydrating effect upon
nitric acid and / or nitration mixtures and / or nitrolysis reactions. Further references have more recently been posted in another more recent thread and some of those references to anhydrous nitrate melts containing magnesium nitrate are also relevant here, so I am linking here to the more recent thread.

http://www.sciencemadness.org/talk/viewthread.php?tid=4457&a...
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[*] posted on 7-9-2010 at 09:57


Just a quick note, I recall reading on roguesci that addition of lithium nitrate helps somewhat. Something to do with helping the linear nitramines become cyclicized or something.

Not sure of the validity of it, but itt was interesting so I remembered it!




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[*] posted on 7-9-2010 at 16:22


I will have to go back and look again, but as I recall some of the lithium nitrate mixtures with other nitrates were anhydrous eutectic mixtures also having dehydrating properties. That would square with the probability or possibility of increasing yields by two different ways if indeed the lithium nitrate alone is beneficial to the nitrolysis. This would possibly work in the same way as does acetic anhydride or phosphorous pentoxide work to tie up water and keep the acid strength high as is required for the nitrolysis.

Boomer hasn't logged in for quite awhile, anybody heard anything ?
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[*] posted on 12-12-2012 at 08:03
E-Process failures


Sorry to dig up this old thread, but I didn’t find any better place in the forum to post my questions about the E-Process.

As acetic anhydride is, for the moment, still easy to get in my country and fifteen times or so cheaper than 100% NA, I decided to give this process a try. Compared to other HE or preparation methods, information is quite scarce about this process, and I didn’t find helpful details beyond Urbanski and the Eble-like method developed by the Canadians (US2434230).

First attempt : 70 ml AA in a tall 200 ml beaker. 1/3 ml of boron trifluoride dehydrate is added (caution : very very weird stuff !). Equipped with a thermometer and a magnet bar, the beaker is put in a water bath on a heating stirrer. When temperature has reached 60°C, 10 g of paraformaldehyde and 27 g of dried ammonium nitrate are added proportionally in tiny amounts over approx 20 minutes. The powders remain in suspension, without any clue that a reaction is underway, in spite of BF3. The mixture becomes progressively yellowish and then colorless after a few minutes. The temperature is maintained in the 65-70°C range for another 15 minutes, and then the beaker is put directly on the heating plate. Stirring and heating are kept on, so as to stabilize temperature around 65°C. As Urbanski states that Para+AN addition takes 6 hours in the industrial process, I leave in another room and come back every 10 minutes to check the beaker. When stirring is interrupted, I can still see the AN prills in the solid phase. Some time later, I notice a strong acetic smell in the house, and discover that a run-awway has occurred at a time I wasn’t attending in the lab. Half of the beaker content had spilled on the stirrer, leaving a yellowish clear solution. The spillage showed traces of a white crystalline product, that I recover for the most part of it, washed with hot water and dried.

Second attempt, inspired by the “Mega-Process” : 70 ml AA in a tall 500 ml beaker. 27 g AN are added in one time, and the mix is heated while stirred until a temperature of 90°C is reached. Beaker is removed from the heating plate, and addition of para starts. First additions cause a light fizzing. The temperature is monitored, and the beaker is put back on the heating plate from time to time so has to keep it in the 85-90°C range. Fizzing becomes more intense with new additions, and at a time, NO2 is emitted and temperature likely exceeds 100°C. A stay in a cold water bath stops the NO2 emission and decreases the fizzing. For the next 10 minutes or so, the exotherm keeps the temperature at 90°C without needing any heating or cooling help. At that time, about 2/3 of the para has been consumed, and the fizzing is decreasing. The solution is pale yellow and limpid, and no more AN prills can be seen. It seems that the reaction is over, which is confirmed by the next additions of para, which cause a very weak fizzing, even when rising the temperature to 90°C with the heating. By the end, a slight layer of a white product shows at the bottom. I leave the temperature drop to ambient, and nothing noticeable happens during that time. The product is filtered and washed with hot water, then dried. The filtrate shows no precipitate whatsoever when crashed in ice water. After re-reading the patent, I saw that the temperature is said to be kept under 100°C at all time.

The two products, when lit by a flame, produce the hissing noise we all know.

Any comment from members having met success through this route and obtained RDX with an acceptable yield are most welcome. Thanks
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[*] posted on 26-7-2013 at 23:37


@ pdb
I too have access to AcAn. But don't want to try the synth at home cause I don't know how much fuming/gas evolution takes place.
I don't want my neighbors getting suspicious of the odors emitted by my kitchen exhaust.
If you can give me some insight as to how much fuming takes place and any peculiar odors ? .... I'll try the synth as I have 3 liters of AcAn. I won't be using BF3 or similar acid.

Also curious if anyone tried nitrolysis of Hexamine with 85% H3PO4 and NH4NO3 ?

Also condensing Nitramide with formaldehyde ?

[Edited on 27-7-2013 by Motherload]




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