Sciencemadness Discussion Board - Making own Nitric Acid

Making own Nitric Acid

guy - 15-4-2004 at 00:11

can u make nitric acid out of ammonia w/ out platinum catalyst?

darkflame89 - 15-4-2004 at 01:15

Maybe, but industrially, ammonia is oxidised at high temp. of 500 degrees celcius, and at pressures of 250 atm, using the catalyst. Nitrogen monoxide is produced which is subsequently furthur oxidised to form NO2, which can then be dissolved in water to get HNO3

Marvin - 15-4-2004 at 04:34

Are you sure you arnt confusing that with the Haber-Bosche process for producing ammonia darkflame?

It can be done without platinum, Iron oxide works, though somewhat less well. Its a difficult process to get working on a small scale, and Megalomania on roguesci has failed to make it work.

hodges - 15-4-2004 at 14:32

http://mattson.creighton.edu/NH3/

Demonstrates making NO2 using NH3 and oxygen at normal atmospheric pressure with a copper catalyst.

darkflame89 - 16-4-2004 at 02:44

Amazing

I can start making nitric acid at home now. If i largescale the process stated at the website, am i going to get any appreciable amounts??

hodges - 16-4-2004 at 16:13

Presumably you can. It will be impure though - at the very least it will contain NH4NO3 since not all of the ammonia will react.

darkflame89 - 17-4-2004 at 05:48

I can always distil the solution right?? Or i can add sulphuric acid in to react with the ammonium nitrate and distill the volatile, nitric acid.

hodges - 17-4-2004 at 11:43

Sure. I thought, though, that since you were trying to make nitric acid this way you didn't have access to other acids or a distiller. If you have sulphuric and a distiller why not just use the ammonium nitrate from a cold pack or fertilizer?

darkflame89 - 18-4-2004 at 00:16

True, true, it is just that while i can improvise a distiller, i definitely do not have sulphuric acid. The strongest acid i can find is phosphuric acid, sold as some kind of anti rust.

This setup has jus a teenny problem, it is quite unable to produce continuous supply of nitric acid; i have to keep taking the coiled copper wire out and heat it on the fire. Anyway to remedy this??

unionised - 18-4-2004 at 02:17

Have a look at this thread
http://www.sciencemadness.org/talk/viewthread.php?tid=1673&a...

The_Davster - 18-4-2004 at 09:14

Darkflame89: You could electroplate some copper onto nichrome wire, and then just use electricty to keep it hot. Or run the ammonia and oxygen through a copper pipe filled with fine copper wire or copper wool and then just heat the pipe.

darkflame89 - 19-4-2004 at 01:43

Good idea that one, i will scoot around to find nichrome wire.

axehandle - 22-4-2004 at 18:03

Quote:

Good idea that one, i will scoot around to find nichrome wire

McGyverize a broken hair drier. It should contain a fair length of coiled NiCr wire.

darkflame89 - 26-4-2004 at 01:52

Upon closer thought, how does Cu catalyse the reaction of ammonia and oxygen to nitrogen monoxide. For starters it might start like:

2Cu + O2 --> 2CuO

Then NH3 + CuO --> ??

darkflame89 - 27-4-2004 at 02:48

Hmm, encountered this website a while ago, it more detailed and have videos.

The reaction is exothermic and keeps the copper wire hot for a long time.

Theoretic - 20-10-2004 at 07:21

If you have AN and a distilling setup, but no acid, use a pinch of salt as a catalyst:

5NH4NO3 => 9H2O + 2HNO3 + 4N2

Marvin - 20-10-2004 at 07:50

On strongly heating ammonium nitrate contaminated with transition metal salts, particually copper there is a large risk of a detonation.

I'm unsure what you meant by 'salt', but I'll assume a copper salt.

Normally it produces N2O of course and any catalyst would have to accelerate one reaction and not the other. Only tiny amounts of acid are produced without a catalyst.

neutrino - 20-10-2004 at 19:14

I think he meant NaCl salt. I remember seeing refernces to a reaction like this on the forum. It is catalysed by chloride ions.

68% nitric acid

Magpie - 26-11-2005 at 21:15

I would like to make the subject acid using sulfuric acid and potassium nitrate.

I have searched and not found a recipe that looked authoritative (or even compeletely believable). However, I have found believable tidbits and have assembled them into my own recipe. I would like to list the parameters for review of the forum, as this exercise has the potential to turn nasty.

Here are my operating assumptions, assuming the following reaction is predominant:

H2SO4 + KNO3 -> HNO3 + KHSO4

1) perform in hood using borosilicate glass vessels
2) use heating mantle, 500 mL RBF, Claisen head, cold water cooled condenser, vacuum adapter, and RBF receiver in ice bath, thermometer at still head; all ground glass fittings wiped free of grease
3) use vacuum distillation at 30 mmHG absolute pressure; estimated boiling temp of azeotrope is 60 deg C
4) use ebulliator to prevent bumping
5) use isolation trap in vacuum line to aspirator
6) use mole ratio of H2SO4/KNO3 =0.674
7) add enough water to give azeotropic 68% HNO3
8) take it slow and use 100 mL H2SO4, at least for the 1st batch

I would appreciate any comments, suggestions, or questions. If all looks good I will perform this preparation and post results with pictures.

The_Davster - 26-11-2005 at 21:44

I would use slightly diluted sulfuric and directly distilling off the azeotropic acid, instead of diluting the fuming nitric after, just for a bit extra margin of safety. After all why mess with the ~98% stuff when you only want ~70%. Also, adding water to your 98% nitric would be very exothermic.

ordenblitz - 26-11-2005 at 23:22

Magpie,

IMHO making HNO3 using sulfuric acid and potassium nitrate is not as difficult or dangerous as you have imagined. I have done it several dozen times, in as many years without incident.
Typically I use a 2000ml flask as the yields from a 500 ml sized batch are fairly small, at least for my effort.
Use a slight excess of H2SO4 as it makes the removal of the sulfate remains from the flask easier. Also when cooling after the distillation, just before the sulfate starts to solidify, carefully add some water from a wash bottle. This keeps a solid concrete mass from forming. If you have a silicone heat mitt, you can pour it out while it is still liquid.
In my experience an ebulliator is not necessary as the distillation is very smooth and tame.
Ice chilling the receiver flask is not necessary if you move a reasonable amount of water through the condenser.
Also, while I have done it under reduced pressure, it really isn't worth the time and effort.
Personally I would use the 98% H2SO4 if you have it, and make the concentrated HNO3. Save some of that and dilute if you need it of lower concentration. Dilution of conc. nitric is a non issue compared to H2SO4.

After you do this for the first time, you will wonder what you were worried about in the first place.

garage chemist - 27-11-2005 at 01:47

Using vacuum creates more problems as it solves if you want to make only 68% HNO3.

With vacuum, the boiling point of the acid will be something like 30°C (if you use dilute H2SO4 to directly distill the 68% acid- if using conc. H2SO4 the bp will be even lower). This calls for highly effective cooling and immersion of the receiver in ice.
Don't use vacuum! Vacuum is only recommended if you want to make white fuming 99% HNO3, i.e. the kind necessary for RDX or PETN.

Distilling HNO3 from KNO3 and H2SO4 is a piece of cake if you have an all- glass distillation setup. Distill at ambient pressure and use dilute H2SO4 which directly gives 68% HNO3.
Let the KNO3/H2SO4 mix stand for about an hour before distilling for the reaction to take place.

Of course you can also distill fuming acid from conc. H2SO4 and KNO3 at ambient pressure, but it will be only of about 90% concentration and of yellow color, due to slight decomposition. But on diluting to 68% this becomes colorless, because at this concentration the dissolved NOx react with the water to form more HNO3.

The 68% acid, no matter if directly distilled or made by diluting fuming acid, should be redistilled and the boiling curve be observed. This is the best method to find out the actual concentration. 68% HNO3 boils constantly at 122°C.

neutrino - 27-11-2005 at 07:42

I can't remember who it was, but someone here talked about distilling at atmospheric pressure vs vacuum. Their conclusion was that a vacuum distillation was no better for decomposition that atmospheric distillation and that most of the decomposition that occurred could be blamed on sunlight.

I can't remember any specifics or which post it was. Maybe someone here remembers, I'm too busy to find it right now.

Magpie - 27-11-2005 at 09:08

Thanks very much for these valuable comments. Most of all thanks for talking me out of using vacuum. I was getting concerned over what HNO3 vapors were going to do to my CPVC and rubber hose vacuum line.

ordenblitz - 27-11-2005 at 10:03

Garage Chemist said:
----------------------------------------
Let the KNO3/H2SO4 mix stand for about an hour before distilling for the reaction to take place.
----------------------------------------

Actually, the displacement reaction starts immediately forming HNO3. No need to wait at all.
In fact, things will happen real fast when using 98% H2SO4. You should probably use a 2 neck flask with an addition funnel for adding the acid because if you use a single neck, you probably won't have enough time to assemble your adapter and condenser before nitric vapors starts coming over.

guy - 27-11-2005 at 21:53

This site shows the video of the catalystic reaction of NH3 and O2 using copper in a lab. The reaction is hot enough to melt the copper.
One could make a design to collect the gas and dissolve it.

Magpie - 28-11-2005 at 18:52

I made some nitric acid today but had to abort about 2/3's of the way through the run due to foaming.

I don't know if this foam is normal or a result of contaminants in one or both of my OTC reactants. I used 236 g of Dexol stump remover and 122 mL of Rooto drain cleaner, and 50 mL water.

I used a 500 mL RBF which is my largest. I would have liked to have had a 750 or a 1-liter to deal with that foam. I cut the heat wnen the foam ran away but it carried reactants all the way into the condenser before subsiding. I have saved everything and will continue tomorrow. I will have to redistill to purify. I'll post pictures when I finish.

Hood works great - didn't smell any NO2 or nitric acid. The downside is that it is tough to keep the lab warm when it is in operation. But it is definitely worth it.

Magpie - 29-11-2005 at 21:14

Finished my nitric acid preparation today. After cleaning up the condenser, etc, I just started up where I left off. Put an aluminum foil tent around pot and distilled away without incident. Never had more than 15 mm of foam. Then redistilled the 1st batch for a combined 95 mL distillate, 62% yield overall. Neutralized the waste salt brine with bicarbonate of soda and disposed down the drain.

Here's a picture with the brine carryover into the condenser and receiver. Also shown is a picture of a Keck clamp that died for the cause. I must have had a joint that wasn't aligned right and it leaked hot nitric acid vapor. It's good to have a hood.

The 2nd picture doesn't want to load but you can see the failing clamp at the top of the Claisen adaptor.

[Edited on 30-11-2005 by Magpie]

foam carryover - nitric acid.JPG - 405kB

foam carryover - nitric acid.JPG - 405kB

BASF - 30-11-2005 at 04:38

I had the same problem with a keck clamp, i used it for my buchi rotavapor for distillation of HNO3... it was a completely new clamp :mad:

PhZ claimed to have used a rotavapor for HNO3 distillation advantageously...so i tried the same.-Only difference: atmospheric distillation.

As i expected, the distillate was quite yellow, at least not deep red...
The rubber sealing of the rotavapor did suffer a lot(it´s made of nitrile rubber or something, but that was too much) although it was not completely destroyed, there was a lot of abrasion.

Yet another idea for HNO3 production at home.

jpsmith123 - 16-12-2005 at 19:12

I don't know why I keep thinking about this. Maybe the idea of making something as useful as HNO3 from air and water, using some relatively simple (hopefully) apparatus, especially in an era when corrupt governments are prone to restrict access to such things, is just too romantic to easily give up on.

I didn't realize that some commercially available high-end heat guns claim to be able to reach 700 degrees C (although they apparently require 2kw or so of power to do it).

Anyway, this temperature exceeds the recommended lower limit of 500 degrees C for producing nitric oxide by way of the method of US patent 5692495, i.e., by "passing air, oxygen enriched air, or air containing a small amount of ammonia, over a noble metal catalyst at an elevated temperature".

I wonder if something as simple as a heat gun blowing 700 degree air over a piece of platinum catalyst from an automobile catalytic converter, for example, can ultimately produce a useful amount of HNO3?

I've been looking all over the place but unfortunately I haven't been able to find any additional information or documentation regarding this method of producing NO.

12AX7 - 16-12-2005 at 19:58

I would suggest... bubble air through an ammonia solution of some concentration. (If necessary, dehydrate the air stream with KOH.) Then lead the gas through a heated copper tube. It's quite easy to heat 3/16" or so oppper tubing to red heat with a small propane torch or bunsen burner. The copper catalyzes the reaction, and if you apply insulation (kaowool or glass wool) it may even sustain itself. Then lead the gasses into more oxygen, if neccessary, to produce NO2, and bubble this into a water solution, or alkali solution if you want faster scrubbing results.

Tim

jpsmith123 - 16-12-2005 at 21:23

That sounds entirely workable to me, and would perhaps lead to a higher rate of production, but at the expense of somewhat more complexity, I would say, both in construction and in operation.

However, the requirement for ammonia (ubiquitous and cheap though it may presently be), nevertheless makes the process dependent on an ingredient that is strictly the product of a large industrial process (that could theoretically become "regulated" someday)...and this makes the process inherently less appealing to me than one requiring only air and water.

[Edited on 17-12-2005 by jpsmith123]

Duster - 17-12-2005 at 00:33

Just a quick jump in...

But it was posted:

"passing air, oxygen enriched air, or air containing a small amount of ammonia, over a noble metal catalyst at an elevated temperature".

I read that as oxygen enriched air OR air with ammonia...

jpsmith123 - 17-12-2005 at 02:08

Hello Duster,

You're right, the patent mentions the use of air with ammonia as an option; personally however, I just have a fetish for doing it without depending on anything like ammonia, if possible.

Also, as a practical matter, I would be willing to trade some amount of production rate and/or energy efficiency, in return for not having to worry about maintaining an ammonia generator and the possibility of an unwanted byproduct of NH4NO3.

Duster - 17-12-2005 at 07:11

Since a setup like this could run for hours on end without ill effect is properly designed, I would think the marginal loss of some production at the lack of an ammona generator would be an acceptable tradeoff. It would be intresting to know what sort of rate of production could be achieved by this method. After all, air is pretty abundunt

neutrino - 17-12-2005 at 10:22

>ammonia ... could theoretically become "regulated" someday...

Aqueous ammonia used for cleaning is unlikely to become severely regulated anytime soon. If all else fails, we can always resort to ammonium salts and bases.

unionised - 17-12-2005 at 10:54

Ammonia isn't going to get meaningfully regulated any time while people still produce urea.

jpsmith123 - 17-12-2005 at 15:31

I used to live in the U.S., now I live in a country that has "banned" all nitrates, chlorates and perchlorates, and probably other chemicals that I'm not yet aware of.

You may be right about ammonia, but it seems there is no limit to government irrationality and abuse, whether in the U.S. or elsewhere; so nothing is out of the question, IMHO.

neutrino - 17-12-2005 at 19:44

As long as fertilizer companies pay politicians, ammonia will be legal.

Now, back to the regularly scheduled topic.

Just leading the air/ammonia mix through the tube will only expose the outermost part of the gas stream to copper. Will this be a problem at this diameters?

The_Davster - 17-12-2005 at 20:14

Well you could do what Organikum did, plating copper onto steel wool, and shoving that down the copper pipe to increase the surface area on the copper.

jpsmith123 - 17-12-2005 at 20:16

I suppose it would depend on the geometry and construction particulars; e.g. the length of the tube, the velocity and turbulence of the air-stream, etc.

If I were going to do it this way I would probably put some "chore girl" copper scouring pad material in the tube to prevent that.

Then I would exhaust the copper tube into a stainless steel tube (or maybe glass tube with stainless steel scouring pad inserted) into which I would also inject more air for the NO to NO2 part.

Rosco Bodine - 2-7-2006 at 16:04

Quote:

Originally posted by neutrino
I can't remember who it was, but someone here talked about distilling at atmospheric pressure vs vacuum. Their conclusion was that a vacuum distillation was no better for decomposition that atmospheric distillation and that most of the decomposition that occurred could be blamed on sunlight.

I can't remember any specifics or which post it was. Maybe someone here remembers, I'm too busy to find it right now.

I remember ..... It was me . Ammonium Pyrosulfate was the thread I started about the dehydration of the ammonium bisulfate niter cake which remains as a residue after HNO3 distillations using ammonium nitrate and H2SO4 . The details of the distillations were described .

https://sciencemadness.org/talk/viewthread.php?tid=4689#pid5...

Fleaker - 1-1-2007 at 20:35

Sorry to resurrect an old thread, but my lab partner (NERV) and I are distilling more nitric acid tonight and figured we would show some pictures of our setup.

We used dirty KNO3 (obtained for about .68 USD/ lb) and drain quality 95% H2SO4 to make this red fuming product. Upon dilution and addition of AgNO3, no clouding or precipitate is observed, so it's at least free of HCl.

First picture is it stored inside PFA 2L bottles (more or less teflon) we took tonight. Second is of it collected in a 1000mL RB flask. Third and final is the distillation setup with 5L 2 neck RBF and 700mm liebig. Those last two are old, but we've been meaning to post them up for some time. BTW, in the small beaker with the yellow solution, that is KCl/HAuCl4 solution for plating.

[Edited on 2-1-2007 by Fleaker]

[Edited on 2-1-2007 by Fleaker]

distillation app.jpg - 163kB

Aqua_Fortis_100% - 2-1-2007 at 22:17

Hello all..
i finish now to read all posts.
i tried ONE time the nitrate/H2SO4 method and mine HNO3 was too weak and expensive which i never more tried..(my problem is the very poor and improvised glasswares, but i will still try the Brainfevert's method...

so if i wish will try anothers methods, as the NH3/Cu at home...
if anyone will can help me about the NH3/Cu method (at home) (if is really reliable, what the major problems which i can have,etc), i try plain in future something based in this method ...
i now imagining something about this method and searching in web..
apparently the problems which i will can have are the oxidation of copper( if generates CuO, this still can work as catalyst????), obviously the nasty effects of ammonia or NOx on body (making the stuff in outside is a cool thing

), etc..

big thanks...
(and also sorry to resurrect an old thread)

[Editado em 3-1-2007 por Aqua_Fortis_100%]

Sauron - 3-1-2007 at 03:26

I think the dry distillation of AN is the usual method of making N2O (nitrous oxide)

And the explosition hazard is only if you accidentally distill the melt to dryness. HOWEVER I am pretty sure this is done with AR grade ammonium nitrate rather than agro fertilizer.

If you have access to H2SO4 why not ptoceed from KNO3 which is generally not as "suspicious" as AN? Sodium bisulphate (sodium hydrogen sulphate) would be a workable substitute.

Can't you buy battery acid? That's H2SO4 and almost as concentrated as the standard lab acid.

Using KNO3 (saltpeter) avoids the explosion risk of AN entirely.

Aqua_Fortis_100% - 3-1-2007 at 11:41

Sauron,
about nitrate/H2SO4 method, the AN should be better because is usually more cheaper than KNO3 or even NaNO3, but this should preheated to dry and no to affect the conc. of HNO3(as NaNO3 - if one wants the >95% HNO3 and using low pressures).. but if anyone as Magpie wants the 68% grade, isn't necessary pressure apparatus and the AN work well...

Quote:

Can't you buy battery acid? That's H2SO4 and almost as concentrated as the standard lab acid.

here the battery acid is no more than 40% (usually 30% or less from used batteries)
i really need buy the 98% grade, but i'm have the "right" age which the local law need ( "older than 18 years and no more than 2 liter of 98% lab grade by mounth without to present documents", etcetera...)
so my source is bring to boil the baterry acid..is free but NOTHING fun...
-----

[Editado em 3-1-2007 por Aqua_Fortis_100%]

Aqua_Fortis_100% - 3-1-2007 at 15:38

<IMG SRC="C:\Documents and Settings\Carlos\Meus documentos\Minhas imagens\Pyroimages\homemadeNOxandHNO3fromNH3.bmp">

[Editado em 3-1-2007 por Aqua_Fortis_100%]

Aqua_Fortis_100% - 3-1-2007 at 15:39

Firstly sorry all about the crap Cu/NH3 design above made in Paint yesterday (is poor because i'm
a newbie even in Paint!!!!), my english, some stupid idea, and also by made two post instead of one
(i tried for 2 HOURS(!!) upload the image ,but without sucess(not showned).only now i tried to modify
the image then works when uploading... so i made two posts to try avoid which image not shown..

I'm interested in this because which is a apparently easy method for HNO3 production at home (although isn't as H2SO4/nitrate method) using raw apparatus (which is VERY convenient for me)

.
This image was based in some (sufficient?) search about catalytic oxidation of ammonia.
almost nothing was found in web about experiments using Cu as catalyst, so i tried search
in this forum and others..
if anyone tried this method or similar, please tell me all and details...
also,if anyone comments this design i really like, even if to only criticize me .
but some questions still affect me:
if the copper is oxodized , the CuO formed still works as catalyst (mentined by Darkflame89) ? if no, is feasible
running a CO or H2 gas in hot CuO to regenerate copper???
any impuritie (as arsenic,etc) in copper can "poisoning"and disturbing terribly the catalyst function of Cu???
Also, problems with unreacted NH3 and NH4NO3 formed..
is possible with this method make great quantities of HNO3 at home? very concentrated???
thanks..
well, about the numbers in design , it's significate which:

1 - ammonium salt/lye/some water to produce NH3 (another question is about how controling the gas flux..i tried put some faucets in design, but i'm really sure which this work best..)
2 - a Hairdryer or , air bubbler(from aquarius) or something to introduce air in system (althoug the hair dryer consume more electricity and as a disadvantage of overheating which was commented by trilobite in another thread..
3 - socket
4 - pieces made from PVC tubes , and some tape to connect them to big plastic bags or gallons containers(as in design) and some sealant or glue for no gas leak..
5 - gallon container or something to mix better the NH3 and air ( now i think which is better a plastic flexible bag , because if applied pressure in them, is better for do a gas stream flux in copper apparatus )
6 - pvc pipe caps sealed with a convenient glue for no gas leak..
7 - (old) faucets to regulate the gasses flux and allow good mix of the gasses..
8 - plastic hoses
9 - long column made with CaCl2 from antifungal or another convenient dissecant agent,to dry the mixed gasses...
10 - small metallic pipe or tube (preferably made with any metal HNO3 resistant) and some PTFE tape..
11 - coke glass bottle

12 - several (homemade) burners..another worry mine is which if a common alcohol burner (which releases relatively low temperatures) can works with this (???), how about a camp gas stove ??? what THE BEST temperature for this, and what the critical temp.(which the formed NO or NO2 can starts to decompose)???
13 - glass tube (from luminiscent Hg lamp).
14 - container with cooled water to receive the NOx and forms HNO3
15 - another container with cold water-ice
16 - glass "cone" made from cutted coke bottle, attached to end of glass tube (works increasing the surface of gas which has contact with water, i think..)
17 - several thin copper pipes and theirs caps (one attached to other by end) - (maybe thin steel or brass pipes works also (and do the project more cheaper). my worry is about the corrosion..the most important it's the pipe filler with Cu things..)
18 - suports for pipes
19 - pipe filler material: several Cu things as Cu plates, wires, coarser powder or fine (CuSO4 + Zn),maybe the Organikum idea ,using steelwool with copper powder ppt on this..but my big worry is if steelwool not burns with the elevated temperatures and with O2 (from NH3/air) passing through it..

edit: the brown pipes which i forget, is a steel or iron tubes which works to reduce progressively the temperature to glass(no pirex) apparatus and avoid termal "stress" of home glass..

[Editado em 3-1-2007 por Aqua_Fortis_100%]

[Editado em 4-1-2007 por Aqua_Fortis_100%]

[Editado em 4-1-2007 por Aqua_Fortis_100%]

guy - 3-1-2007 at 15:47

The idea is that CuO oxidizes NH3 to NO gas.

Unbalanced equations:

CuO + NH3 ----> NO + Cu + H2O

Cu + O2 ---> CuO
-------------------------------
NH3 + O2 ---> NO + H2O

YOu need very high temperature to selectivly produce NO or else you just get N2 or N2O.

[Edited on 1/3/2007 by guy]

Aqua_Fortis_100% - 3-1-2007 at 15:53

guy,
if i attach a blow torch or then even burner with a oxigen cylinder (with proper care..cylinders of compressed gas has a LOT of hazards..) can work well?
but another worry is if the burns is too hot and melt apparatus..
thanks about CuO.. so this project can be really real...
in next holidays certainly i will try..

guy - 3-1-2007 at 16:06

Quote:

Originally posted by Aqua_Fortis_100%
guy,
if i attach a blow torch or then even burner with a oxigen cylinder (with proper care..cylinders of compressed gas has a LOT of hazards..) can work well?
but another worry is if the burns is too hot and melt apparatus..
thanks about CuO.. so this project can be really real...
in next holidays certainly i will try..

I think that will work. The good thing is that once it has started, the reaction is so exothermic that it will sustain itself,even melt the copper!

I have tried to do this but never had a good heat source. Maybe you can be the one to finally make it work.

Catalytic Oxidation of NH3 with copper

Aqua_Fortis_100% - 3-1-2007 at 16:14

OH Thanks again guy!
i printed infos from this site, and other site which showns in 1 page of this thread ,yesterday!

about the exothermic reaction: i think which maybe works as solution or as problem ("even melt the copper!")..and from site:

Ammonia is catalytically oxidized at the platinum surface according to the following reaction.
5 NH3 (g) + 5 O 2 (g) ---> 4 NO (g) + 6 H2O (g)
The reaction is exothermic and as written releases 920 kJ of energy. A second reaction proceeds automatically from the first reaction.
2 NO (g) + O 2 (g) ---> 2 NO2 (g)
The second reaction is also exothermic and as written releases 112 kJ of energy.

-------------
How about Another thing which i will try is one "improvised" way to gets HNO3 in another thread where

Quote:

Lambda said:
Making Nitric acid with Potassium permanganate, Ammonia gas and recycling the process with Air (Oxygen) ???

I have forgotten the title of this book, but I think it was written by Robert Gatling. The Paladine Press once published it, and I have the book. When I find it, a scan will be made.

What doese the author of this book claime ?:

According to the author of this book, Nitric acid can be made by bubbling Ammonia gas through a solution of Potassium permanganate. The Ammonia gas is oxidized to Nitric acid in this way. Potassium permanganate may again be obtained by bubbling Air (Oxygen) through this solution (?). And thus, the whole process may be repeated, by only applying Ammonia gas, and again recycling with Air. A continuos process, may thus be astablished for the production of Nitric Acid.

Do you think that this process is feasible ?

but i'm not sure if this method works when anyone wants conc. HNO3, and how to separe the HNO3 from Mn salts solution..(maybe distillation?)....maybe isn't a "EASY" way as showns... how about?

[Editado em 4-1-2007 por Aqua_Fortis_100%]

guy - 3-1-2007 at 17:21

Quote:

Originally posted by Aqua_Fortis_100%
OH Thanks again guy!
i printed infos from this site, and other site which showns in 1 page of this thread ,yesterday!

about the exothermic reaction: i think which maybe works as solution or as problem ("even melt the copper!")..and from site:

Ammonia is catalytically oxidized at the platinum surface according to the following reaction.
5 NH3 (g) + 5 O 2 (g) ---> 4 NO (g) + 6 H2O (g)
The reaction is exothermic and as written releases 920 kJ of energy. A second reaction proceeds automatically from the first reaction.
2 NO (g) + O 2 (g) ---> 2 NO2 (g)
The second reaction is also exothermic and as written releases 112 kJ of energy.

-------------
How about Another thing which i will try is one "improvised" way to gets HNO3 in another thread where

Quote:

I don't think the permanganate route is feasible. I once tried putting potassium permangate in ammonia solution and I did not see any MnO2. And O2 cannot regenerate MnO4- because it is not a strong enough oxidizer.

Aqua_Fortis_100% - 3-1-2007 at 17:29

but and the tracherous Mn2O7 gas? mixed with NH3 gas can be a stupid idea? (BOOOM!) or the oxidation isn't too violent?
i think also which make this in gas isn't a good idea, because of the great risks..(with several accidents mentioned in some threads..)
-------
but if anyone will can make a Ozone generator? this is sufficient to oxodize ammonia in NOx ???
thanks

[Editado em 4-1-2007 por Aqua_Fortis_100%]

guy - 3-1-2007 at 17:40

Quote:

Originally posted by Aqua_Fortis_100%
but and the tracherous Mn2O7 gas? mixed with NH3 gas can be a stupid idea? (BOOOM!) or the oxidation isn't too violent?
i think also which make this in gas isn't a good idea, because of the great risks..(with several accidents mentioned in some threads..)
-------
but if anyone will can make a Ozone generator? this is sufficient to oxodize ammonia in NOx ???
thanks

[Editado em 4-1-2007 por Aqua_Fortis_100%]

Ozone will oxidize ammonia to ammonium nitrite and ammonium nitrate.

from Wikipedia

Quote:

2 NH3 + 4 O3 → NH4NO3 + 4 O2 + H2O

Aqua_Fortis_100% - 3-1-2007 at 18:33

really thanks guy, to shown me the true..
although now i'm dissappointed about ozone and others oxodizers(KMnO4,etc..)..
so i now will concentrate on Cu/NH3 method, and if all gives right, i post my experiments in next holidays... i tried think about some more oxodizer to oxodize the amonia into HNO3 ,but have'nt success.. :mad:

with solid oxodizers (alone or in solution) : even if oxodizes ammonia, one will has great problems probably due the difficults in separate this HNO3 from others products,etc moreover can be a lot expensive...
about the gas oxodizers, ozone is now discarded because

Quote:

originally posted by guy
Ozone will oxidize ammonia to ammonium nitrite and ammonium nitrate.

so, others oxodizer as N2O under high temp. can work also (releases more O2 than which air contains..) .. i can meke it simple reacting (NH4)2SO4 with nitrate under heating but should be unfeasible and MUCH more expensive than using free air as O2 source.. but about the measures, i read also in wikipedia which

Quote:

The most important single use of ammonia is in the production of nitric acid. A mixture of one part ammonia to nine parts air is passed over a platinum gauze catalyst at 850 °C, whereupon the ammonia is oxidized to nitric oxide.

wow,apparently my future difficult should be mix in this rate an allow reacting CONTINUOUSLY in homemade NH3 oxodizer (previous)..

aboout nitrate/H2SO4 method ,another thing if anyone has some Ca(NO3)2 , can make relatively "pure"(with slighty amounts of H2SO4 excess or Ca(NO3)2 excess) HNO3 without need destill the mix...simple passing in glasswool for remove the CaSO4 ppt in solution... (although isn't better than conventional H2SO4/nitrate destillation and moreover is almost impossible get HNO3 of high conc.. (maybe using oleum instead????))
using others nitrates as Pb(NO3)2, Ba(NO3)2,AgNO3, etc also will work but i think which this is almost a insane act.. these chemicals , (specially the AgNO3) are even MUCH more expensive than HNO3! and moreover, with these nitrates some fun things can will be created..(as Ag2C2 or Ag3C2NO3, with Pb(NO3)2 is possible to make some monomethylamine nitrate without need HNO3, etc..)
Cu/ammonia maybe will be the future for improvisational chemists!!!

[Editado em 4-1-2007 por Aqua_Fortis_100%]

gnitseretni - 6-1-2007 at 10:18

Quote:

Originally posted by garage chemist
Of course you can also distill fuming acid from conc. H2SO4 and KNO3 at ambient pressure, but it will be only of about 90% concentration and of yellow color, due to slight decomposition.

Can one get a slightly higher yield by distilling at a lower temperature or is the only way to prevent decomposition of HNO3 by distilling at reduced pressure?

BTW, is the use of a certain nitrate in the production of HNO3 just a preference, will they all work, or is there a reason why some use potassium nitrate, others ammonium nitrate, etc?

Aqua_Fortis_100% - 6-1-2007 at 11:03

Quote:

Originally posted by gnitseretni :

Can one get a slightly higher yield by distilling at a lower temperature or is the only way to prevent decomposition of HNO3 by distilling at reduced pressure?

Maybe really reduce the decomposition of HNO3 but in other hand, works too slow if distill in low temperatures using ambient pressure.
so i really need buy all of distill apparatus (specially the low pressures apparatus)..

Quote:

Originally posted by gnitseretni :

BTW, is the use of a certain nitrate in the production of HNO3 just a preference, will they all work, or is there a reason why some use potassium nitrate, others ammonium nitrate, etc?

i think which depends of what nitrate is more cheap to one obtains or then, major prefer KNO3 because using NH4NO3 or NaNO3 is more prone to contain some water which prejudices the Fuming HNO3 production.. so who uses NH4NO3 or other hygroscopic nitrate must DRY perfectly instants before distill with high conc. of H2SO4...

gnitseretni - 6-1-2007 at 21:04

Quote:

Originally posted by Aqua_Fortis_100%
so i really need buy all of distill apparatus (specially the low pressures apparatus)..

Something like this

68% nitric acid production

-jeffB - 10-2-2008 at 12:43

I've refrained from asking this, as it seems TFSE should yield the answer I want, but I haven't been able to find a definitive answer. So, I'd like to appeal to those here with direct experience.

I have concentrated sulfuric acid drain cleaner (I haven't titrated it, but I assume it's >90%). I have sodium and potassium nitrate. I have sufficient ST glassware to do straight or fractional distillation. I have some vacuum equipment, but I'd rather not use it if I can avoid it; I don't want to run an aspirator because of a severe regional drought, and I don't want to run acidic vapors through the oil of my mechanical pump.

I want NOT to produce nitric acid in anything greater than the standard 68% azeotropic mix with water. I do NOT want fuming nitric acid, red, white, or chartreuse.

From previous threads, I have the impression that just grinding the NaNO3 and boiling it at standard pressure in the H2SO4 will produce something like 90% HNO3, with lots of oxide contamination. I get the impression that diluting the reaction mix with water might reduce this problem, and allow me to take off the azeotrope (at 120.5C) without significant decomposition. I don't know whether to expect an H2O fraction to come off first. I don't know whether a Vigreux column is necessary, insufficient, or overkill; I'd be inclined to try it without one.

Am I on the right track? Am I on a dangerously wrong track? Any tips on more effective ways to UTFSE -- I've been using Google search with site:sciencemadness.org, as the forum's form-based search engine seems a bit limited.

I promise to take useful advice to heart, and not to take criticism personally...

Magpie - 10-2-2008 at 13:50

You're on the right track. Read the following thread:

http://sciencemadness.org/talk/viewthread.php?tid=1851&p...

If you still have questions just fire away.

The_Davster - 10-2-2008 at 14:00

First off, how much acid are you in need of?

With a water/ azeotrope boiling point separation of only 20C, I would be inclined to use a vigreaux collumn.

You will not want to use concentrated sulfuric acid with the nitrate, as that will produce a ~65C fraction of fuming red acid if done under atmospheric pressure. The sulfuric should be diluted to such a concentration that when you calculate it out, there is enough water, plus a slight excess, to not have greater than azeotropic acid when mixed with nitrate. Then fractionally distill with the vigreaux collumn, you should collect a small ~100C fraction of water, then collect the ~120C fraction of azeotropic acid

This thread(http://www.sciencemadness.org/talk/viewthread.php?tid=4689&a...) discusses azeotropic distillation, but if I can find a more applicable thread, I will merge this into it.

microcosmicus - 10-2-2008 at 14:16

Quote:

I don't want to run an aspirator because of a severe regional drought,

A minor point, but you could use a closed system with a pump instead
of attaching the aspirator to the sink. Of course there is the issue of
the acidic vapors dissolved in the water not being too good for the
water pump, but this might not be so bad because a. they would be
diluted, b. something like the typical plastic sump pump should stand
up to dilute acids just fine and c. one could always add some soda to the
water to neutralize the acid.

-jeffB - 10-2-2008 at 15:33

Quote:

Originally posted by The_Davster
First off, how much acid are you in need of?

Well, technically, I guess I don't need any.

I'd probably be looking at something on the order of a hundred grams at a time. Going large, I can't imagine ever making more than a kg at a time. Going small, my gear is 24/40, so running down in the 10g scale would probably mean I'd hold up more product than I'd collect.

Quote:

With a water/ azeotrope boiling point separation of only 20C, I would be inclined to use a vigreaux collumn.

You will not want to use concentrated sulfuric acid with the nitrate, as that will produce a ~65C fraction of fuming red acid if done under atmospheric pressure. The sulfuric should be diluted to such a concentration that when you calculate it out, there is enough water, plus a slight excess, to not have greater than azeotropic acid when mixed with nitrate. Then fractionally distill with the vigreaux collumn, you should collect a small ~100C fraction of water, then collect the ~120C fraction of azeotropic acid

This thread(http://www.sciencemadness.org/talk/viewthread.php?tid=4689&a...) discusses azeotropic distillation, but if I can find a more applicable thread, I will merge this into it.

That's exactly the kind of information I'm looking for. Thanks, and thanks for moving this to the appropriate spot!

(EDIT By Davster: Credit where it is due, my laptop froze, and when I bothered to restart a couple hours later, someone else moved it here.)

[Edited on 10-2-2008 by The_Davster]

-jeffB - 10-2-2008 at 15:35

Quote:

Originally posted by microcosmicus

Quote:

I don't want to run an aspirator because of a severe regional drought,

Interesting idea. I'd sort of assumed that an aspirator would require more head pressure and/or flow than a small, cheap, not intolerably loud pump could provide. I already have a closed system for cooling water -- a box on wheels I bought at surplus, containing a tank, a stirrer, a peristaltic pump, some tubing, and a pressure gauge. For that matter, I suppose I could rig a small aquarium pump for circulation, and use the peristaltic pump for vacuum, as discussed in a recent thread.

497 - 16-2-2008 at 20:38

So I'm thinking about testing the viability of a batch process to produce easy NO2 from NH3 and O2. I'm thinking some kind of steel vessel that you could simply fill with NH4 and then pressurize with O2 from a torch up to the appropriate ratio of gases. A copper wire of decent thickness could be electrically heated to initiate the reaction.

What I'm not sure about is how much NH4NO3 would be produced, thus wasting the NO2. Do you think this would be a problem? I'm going to try to test it on a small scale tonight if all goes well.

Edit:

Not good results, it mostly produces a cloud of ammonium nitrate. Too bad. I'll have to try something else.

[Edited on 16-2-2008 by 497]

crazyboy - 2-3-2008 at 13:46

Sorry for digging up this old thread but I have a question. I would like to distill nitric acid in an all glass distillation setup (no shortcuts) but from what I have read the resulting nitric acid will be of the red fuming variety. Wouldn’t that mean its no good for nitrations? If so is there a way to avoid the red fuming variety? Also in the TNT preparation thread there is mention of reusing acids by heating 70% nitric with 93%-98% sulfuric acid resulting in 99% purity. Would this be white fuming or red fuming nitric acid? If it is white fuming what would be a good ratio of 70% nitric acid to 98% sulfuric acid (not spent acid) to distill 99% nitric? Thanks for all the help.

woelen - 2-3-2008 at 14:31

The nitric acid indeed contains some NO2. I myself also did this distillation, and I obtained some yellow acid, which I think has concentration better than 90%. One way to get rid of the NOx is the addition of a small amount of urea. This reacts to form N2, CO2 and H2O. It of course does decrease the concentration of the acid a little, but if you start with yellow acid, then the decrease is not dramatic.

This is the setup I used for making a small amount of the concentrated acid:

http://woelen.homescience.net/science/chem/exps/raw_material...

I understood (but did not try myself) that redistilling the red or yellow acid in vacuum allows for a much whiter acid, if the first part of the distilled matter is discarded (it contains the NOx). The last part of the distilled matter also should be separated as well (it is more dilute, its concentration goes towards the azeotrope of 68%, don't discard it, its useful for other things, but keep it separately).

Edit(woelen): Made link work again.

[Edited on 30-7-16 by woelen]

franklyn - 30-5-2010 at 15:52

Manufactue of Nitric Acid
http://www.platinummetalsreview.com/pdf/pmr-v11-i1-002-009.p...

.

Random - 3-9-2010 at 14:08

Nurdrage made nitric acid with reaction of nitrate salt, hcl and copper to make no2 and dissolved it in the water to make HNO3.

I am interested in doing that, but I am afraid of NO2 poisoning. Is it really that dangerous?

rrkss - 3-9-2010 at 21:48

Quote: Originally posted by Random

Nurdrage made nitric acid with reaction of nitrate salt, hcl and copper to make no2 and dissolved it in the water to make HNO3.

I am interested in doing that, but I am afraid of NO2 poisoning. Is it really that dangerous?

You can make a very weak Nitric Acid that way. As long as you don't breathe the NO2 you will be fine. The smell is obvious if you get a whiff.

Random - 4-9-2010 at 08:53

What could happen if I will get more than a whiff?

rrkss - 4-9-2010 at 11:11

If you do the chemistry outdoors or in a fume hood, and don't stick your face in the beakers, you are not going to get more than a whiff.

I've done chemistry where I made tons of NO2 and did it outside. The gas is dark brown and obvious.

HNO3 from Aluminum Nitrate + H2SO4 electrolyte

Rosco Bodine - 8-9-2010 at 07:45

It has been an intriguing idea for which I have never done any experiments to see if this idea would work or not. But it may be possible to use a cheap alternative nitrate precursor which may produce a good, possibly better yield of nitric acid from the distillation using H2SO4 by reacting with both hydrogens of H2SO4 rather than just one, not producing an acid sulfate byproduct "niter cake" as is the usual result, but producing a normal sulfate byproduct instead, thereby also producing twice the amount of HNO3 from the same amount of H2SO4, which would be a doubling of the efficiency of the commonly known reaction. A nitrate of a metal which may possibly work in this manner is Aluminum Nitrate, Al(NO3)3. Aluminum Nitrate could possibly be gotten from amalgamated scrap aluminum decomposition in an ammonium nitrate solution. Alternately the reaction of Calcium Nitrate with Aluminum Sulfate may be convenient,
and would provide a recycle loop for the Aluminum Sulfate byproduct, if Calcium Nitrate is the easily available nitrate feedstock. The terminal waste byproduct of the process would be Calcium Sulfate, gypsum. Because of the water sequestering properties of both the Aluminum Nitrate and the Aluminum Sulfate byproduct in the distillation mixture, a lower concentration H2SO4 may be workable for producing a higher concentration HNO3 distillate since both salts would tend to break the azeotrope in the reaction mixture itself.
How pronounced would be the effect is not known but it would seem possible that even ordinary electrolyte strength H2SO4 may be sufficient for distillation of azeotropic HNO3.
This has not been described in the literature which I have read and I really don't know if it would work or not, but the idea is certainly intriguing and is on my experiments to do list.

There is a decomposition temperature for Al(NO3)2 at 14C higher than the temperature of distillation for azeotropic HNO3, but that seems to be an acceptable margin for a carefully conducted process, unless the decomposition temperature is lowered by the acid conditions of the reaction mixture .....which could be the "hitch" that may prevent the process from being workable.

2 Al(NO3)3 + 3 H2SO4 -----> Al2(SO4)3 + 6 HNO3

Anyone having any further information on this idea for
possible use of Aluminum Nitrate as an HNO3 distillation precursor please share your thoughts and / or information

It seems likely somebody may have already been there - done that, and it is just an obscure matter for which I haven't found a thing written ...yet.

[Edited on 8-9-2010 by Rosco Bodine]

hissingnoise - 8-9-2010 at 10:06

Al(NO3)3, hygroscopic, normally containing considerable water of hydration and decomposing below 140*C doesn't IMO, look very promising as a source of HNO3.
If it was a viable method, I think it would be fairly common knowledge. . .
If it can be dehydrated without the salt decomposing it might have interest.

Rosco Bodine - 8-9-2010 at 11:02

Quote: Originally posted by hissingnoise

Al(NO3)3, hygroscopic, normally containing considerable water of hydration and decomposing below 140*C doesn't IMO, look very promising as a source of HNO3.
If it was a viable method, I think it would be fairly common knowledge. . .
If it can be dehydrated without the salt decomposing it might have interest.

I fail to understand your logic for why Al(NO3)3 does not look promising as a source for HNO3. The 135C decomposition point is well above the distillation temperature for both azeotropic and pure HNO3, and dehydration of the Al(NO3)3
is not the proposed reaction, double decomposition is the proposed reaction.

As for the conditional supposition that if it was a viable method then it would be common knowledge, that seems to be excessively presumptuous in being dismissive of a reaction which would not seem at first glance to be so far fetched. Don't misunderstand me because I don't know if it will work or not, but nothing you just said is sufficient for actually dismissing the idea. I still think the idea may be a possibly valid approach for improving a very old reaction. And it may not be a new idea at all. It may already be a described method for which the description is obscure enough that it is not easily found.

MSDS for the Fisher reagent nonahydrate of Al(NO3)3 shows the hydrate melts at 73.9C and has a B.P. with decomposition at 150C.

Byproduct Al2(SO4)3 - 18H2O has a melting point of 86.5C

It would appear that it would be better to in advance break the nonahydrate some way, such as by possible mixture with another nitrate perhaps zinc nitrate ? To further develop the idea I will see what I can find about that, but really that has more bearing upon concentration of the anticipated HNO3 which may be produced, than would it have bearing upon whether or not the contemplated reaction occurs. The greater concern I have is that an unfavorable equilibrium may exist for an actual acid sulfate
of aluminum to occur which would then stop the reaction in the same way as occurs for the classical and well known reaction.

[Edited on 8-9-2010 by Rosco Bodine]

hissingnoise - 8-9-2010 at 11:51

Quote:

I fail to understand your logic for why Al(NO3)3 does not look promising as a source for HNO3.

It's just an opinion based on a hunch - but I think the tradition of using Na or K salts is based on experience. . .

Rosco Bodine - 8-9-2010 at 13:02

Your hunch is probably incorrect. Some further reading is revealing that extraction of aluminum ore using nitric acid is the common purification method as the preliminary purification and isolation of alumina via thermal decomposition of the nonahydrate, with recovery of the nitric acid for recycling in the process. The aluminum nitrate readily gives up its nitric acid by heating alone, and the first
30% of the acid comes off as a 48-50% concentration. However, by thermal decomposition the byproduct is alumina intended for electrolytic cell feedstock.
But in the process to which my idea applies, the end product desired is not alumina nor aluminum, but the desired product is the nitric acid itself. In the presence of H2SO4, the HNO3 should be given up even more readily than by thermal decomposition alone, while producing Al2(SO4)3 as the byproduct instead of Al2O3. Everything looks favorable for the reaction which I am thinking should work. So the heck with your opinion based on a hunch on this one

as the reaction kinetics seem to be there in favor for the reaction I am hypothesizing should occur.

[Edited on 8-9-2010 by Rosco Bodine]

hissingnoise - 9-9-2010 at 01:42

Quote:

So the heck with your opinion

Gee Rosco, I'm sorry you find my lack of enthusiasm upsetting. . .

Rosco Bodine - 9-9-2010 at 02:53

There you go again with the negative waves

http://www.youtube.com/watch?v=AhKnEo9ZyEs&feature=relat...
Think positive when you are on the way to the bank

http://www.youtube.com/watch?v=WBr2Xh599ZI&fmt=18

The process or at least the distillation part of the process where H2SO4 is used for conversion of Al(NO3)3 to HNO3 and Al2(SO4)3 is described in the English language summary of a couple of Japanese patents. So it would seem my hypothesis does have some validity and has partly been described in what would be an understandably obscure source to an English speaking person.

Fortunately the chemicals and reactions involved will likely not be rendered inert
in protest for my inability to speak Japanese, but who can be certain ?

Abstract of JP 6001603

PURPOSE:To improve recovery efficiency by adding sulfuric acid to spent nitric acid contg. phosphoric acid and Al so as to have not less than the specified SO4/Al molar ratio before concentrating the mixture by distillation to the specified free sulfuric acid concentration to recover nitric acid. CONSTITUTION:Sulfuric acid is added to spent nitric acid contg. phosphoric acid and Al so as to have >=3 molar SO4/Al ratio to convert nitrate to nitric acid and the mixture is concentrated by distillation until the free sulfturic acid concentration becomes 25-50wt.% to recover nitric acid in the spent acid by >=90%. Then, after warm water is added to the remained liquid to adjust it so that it may become supersatrated solution of Al2(SO4)3, a seed crystal is added to it to cool it and after a crystal of Al2(SO4)2 is deposited, it is separated from the mother liquor by filtration.; In another treatment of the remained liquid after nitric acid recovery, after Fe content is added to the liquid by the specified quantity to make the ratio of free sulfuric acid to FeSO4 be <0.5, it is heat treated and brought into contact with air to oxidize it and the formed insoluble content is filtered and removed to prepare and use a solution essentially consisting of Al2(SO4)3, Fe2(SO4)3 and phosphoric acid.

Abstract of KR 20020051204

PURPOSE: A method for reusing a waste etching solution containing nitric acid with an etching solution and an aluminum sulfate water treatment coagulant is provided to reduce a cost required to the treatment of waste acid, and to solve a problem of sludge reclamation. CONSTITUTION: The method for reusing a waste etching solution containing nitric acid comprises: a first step for manufacturing an aluminum sulfate solution by dissolving an aluminum component such that the density of aluminum in sulfuric acid is 10 to 60g/l; a second step for separating the waste etching solution containing aluminum and nitric acid generated from an etching process of an aluminum foil into a nitric acid solution and an aluminum nitrate waste solution by using a diffusion dialysis method; a third step for mixing the aluminum sulfate solution and the aluminum nitrate waste solution, heating the mixture at 100 to 200deg.C to evaporate the nitric acid, and cooling them to withdraw the nitric acid and to transpose the aluminum nitrate into the aluminum sulfate; and a fourth step for adjusting a density of the nitric acid into a range of 130 to 150g/l so as to use it as an etching solution, and adjusting a density of the aluminum sulfate solution into a range of 35 to 45g/l so as to use it as an aluminum sulfate water treatment coagulant.

Abstract of JP 10310427

PROBLEM TO BE SOLVED: To provide a method for treating spent nitric acid by separating aluminum from a processing soln. contaminated by the aluminum generated in the electrolysis of aluminum foil as an aluminum nitrate crystal, then removing aluminum sulfate by further treatment and controlling the composition of the separated mother liquor to make it recyclable. SOLUTION: A spent nitric acid contg. dissolved aluminum is evaporated and concentrated, then mixed with concd. nitric acid and cooled to separate an aluminum nitrate crystal, the separated aluminum nitrate crystal is dissolved in water (dil. nitric acid), sulfuric acid is mixed with the soln., and the mixture is evaporated and concentrated. Water is added to the liq. concentrate to form liq. aluminum sulfate, or the liq. concentrate is cooled to obtain crystallized aluminum sulfate.

Abstract of JP 2001054988

PROBLEM TO BE SOLVED: To provide an efficient method for treating waste nitric acid liquid for recovering high purity nitric acid from waste nitric acid liquid containing aluminum generated in a lithographic printing production process for recycling with energy consumption reduced. SOLUTION: A reaction process in which waste nitric acid liquid containing aluminum which is generated in a lithographic printing production process is added with sulfuric acid in an amount 1.0-1.5 times in mole ratio as large as the amount of aluminum in the waste liquid to produce aluminum sulfate and a distillation process in which nitric acid separated in the reaction process is separated/recovered by distillation are provided. Preferably, the distillation process has an aluminum sulfate recovery process in which liquid containing aluminum sulfate is transferred from the bottom part of a distillation still to a crystallization tank, in which aluminum sulfate is deposited and separated/ recovered from the nitric acid solution.

[Edited on 9-9-2010 by Rosco Bodine]

hissingnoise - 9-9-2010 at 08:58

I don't doubt that you can distill usable amounts of HNO3 from your Al(NO3)3 but the level of convenience or otherwise remains to be seen. . .

[Edited on 9-9-2010 by hissingnoise]

Rosco Bodine - 9-9-2010 at 09:51

What I was considering is using NH4NO3 as the source nitrate and using scrap aluminum electrical cable which is very pure aluminum wire as the source of aluminum, amalgamating it to faciltiate the reaction with NH4NO3 solution.
The NH3 which evolves can be salvaged and sequestered as hexamine by
dispersion of the ammonia into a second jug of water and paraformaldehyde
(mildewcide) crystals, so I have no waste by venting the ammonia nitrogen but obtain a useful byproduct. These reactions should proceed slowly unattended
and go to completion. The few globules of mercury separate at the end when all the aluminum is consumed and can be recycled also. I end up with one jug of
Al(NO3)3 solution and another jug of hexamine solution. Hmmmmmm.....
This sounds increasingly interesting huh ?

Alternately, Calcium Hydroxide and NH4NO3 solution can be reacted and the resulting Calcium Nitrate solution can be reacted with Aluminum Sulfate, precipitating Calcium Sulfate and filtering off the Aluminum Nitrate solution which is evaporated to obtain the Al(NO3)3 - 9 H2O

From the proposed variation upon the classic nitrate distillation, twice the yield of HNO3 should be produced
from the same amount of H2SO4 consumed.

It will probably be a low concentration HNO3 unless the 9 hydrate Al(NO3)3 can be broken in advance. But no big deal if the HNO3 has to be redistilled to concentrate it using a mixed anhydrous nitrate salt for breaking the azeotrope.

Everything is recycled, except the H2SO4 and Ca(OH)2, and there is twice as much HNO3 produced for the effort. If a significant amount of acid is desired at low cost, the effort could be worthwhile.

[Edited on 9-9-2010 by Rosco Bodine]

White Yeti - 4-8-2011 at 07:42

You can make ammonium nitrate from ammonia and ozone, and then you can turn the ammonium nitrate into nitric acid by heating it with sulphuric acid and distilling. It's probably not worth the trouble though.

AndersHoveland - 4-8-2011 at 09:33

Aluminium trinitrate is probably not a good route. Thermal decomposition of the hydrate results in the compound losing losing its nitrate groups before all the H2O molecules of hydration have been removed. So this does not seem like a feasible route to obtaining concentrated nitric acid.

http://www.sciencedirect.com/science/article/pii/S0040603101...