# cold nitric recipe, another observation



## au-artifax (Jan 9, 2014)

Hello all. First off, I really enjoy the ease of making nitric with Steve's recipe. It is simple and quick. 

On time though, I didn't get quite the output expected. I followed the recipe to the letter as always, and I use KNO3 to do mine and have had no issues. This particular batch I did by weighing the sulfuric and KNO3, which I find easier than doing volumetric with one and weight with another. Also, I kept the mixture down to -10C overnight with great crystalization and clear product, slightly yellow and very reactive.

Here's what I did though: I took the leftover crystal mass, added 200ml of distilled water to the same reaction vessel, heated till all was disolved again, yada yada, same process, and I got a whole nother batch with slightly more output than the first.

After the first batch the crystals were yellowish, but the second, they are almost white... just a hint of yellow.

I tested the reactivity and great results processing the material a second time.

The one thing I did not do yet, because I am doing a third round, is do a specific gravity test on all three batches combined.

Has anyone ever re-processed the cold nitric recipe like this? And for anyone who asks about the amounts used, I used exactly the ratio the recipe asked for, but doubled.

Is there anything else I should be thinking about here that might be a good idea? I think maybe it would benefit anyone who does this recipe to consider running the process again by adding some more DW.

Comments?


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## butcher (Jan 9, 2014)

Sodium nitrate does not have the same problem KNO3 does, the sodium sulfate salts are smaller crystals they do not trap nitric acid like the potassium sulfate salts can, If the nitric acid is cooled too fast with the potassium sulfate salts forming quickly most of the nitric acid can get trapped in the crystal structure of the salts, very slow cooling can help to slowly form crystals and thus trap less of the nitric acid in the potassium sulfate salt.


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## au-artifax (Jan 11, 2014)

butcher said:


> Sodium nitrate does not have the same problem KNO3 does, the sodium sulfate salts are smaller crystals they do not trap nitric acid like the potassium sulfate salts can, If the nitric acid is cooled too fast with the potassium sulfate salts forming quickly most of the nitric acid can get trapped in the crystal structure of the salts, very slow cooling can help to slowly form crystals and thus trap less of the nitric acid in the potassium sulfate salt.



Yes butcher, that is exactly what happened, and thank you for cluing me in on how kno3 reacts. In fact, I transfered the reaction vessel from around 50°C to a -10°C ice blanket directly.

I will try it slower like you said next time.

Thank you.


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## au-artifax (Jan 11, 2014)

butcher said:


> Sodium nitrate does not have the same problem KNO3 does, the sodium sulfate salts are smaller crystals they do not trap nitric acid like the potassium sulfate salts can, If the nitric acid is cooled too fast with the potassium sulfate salts forming quickly most of the nitric acid can get trapped in the crystal structure of the salts, very slow cooling can help to slowly form crystals and thus trap less of the nitric acid in the potassium sulfate salt.




And one more quick question; do you thing I should let it cool slower to roomtemp.also, as I saw crystals forming before it reached room temp, and that is the point where I iced the batch.


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## butcher (Jan 11, 2014)

First I make sure that all salts are dissolved before cooling it back down to room temperature, this way the nitric acid and potassium sulfate salts are both in solution, to insure a complete reaction of all of the potassium nitrate with the sulfuric acid solution.

Much of the potassium sulfate salts will form after lowering heat from the initial reaction, slow cooling to room temperature, and a stir to bust up crystals, I decant the nitric acid from these initial salts before freezing (where more salts will form), because the solubility of the potassium sulfate being lower at these colder temperatures.


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## rickbb (Sep 27, 2014)

I hate to bring back old threads, but;

I'm using Steve's cold recipe for the first time. He states to boil 100 ml of water then stir in 202gm's of either potassium nitrate or 170gm's sodium nitrate, I'm using potassium. (Spectracide Stump Remover, MSDS says its 100% KNO3.)

So far so good, I've added in the KNO3, stirred until it has completely dissolved, but, when it starts cooling off the KNO3 is precipitating back out. The cooler it gets the more KNO3 crystals form.

I need more than that what his recipe he has posted, so I doubled all the quantities, 200 ml water, 404gm's KNO3 and was going to use 112ml of concentrated sulfuric acid to produce a yield of ~320ml 50\50 nitric.

Obviously I've done something wrong here, can anyone point me in the right direction? Was I wrong to assume that a simple doubling of the water and KNO3 would work? It seems I'm over the saturation point of KNO3 in the volume of water since it precipitates back out when cooled.


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## FrugalRefiner (Sep 27, 2014)

rickbb said:


> So far so good, I've added in the KNO3, stirred until it has completely dissolved, but, when it starts cooling off the KNO3 is precipitating back out. The cooler it gets the more KNO3 crystals form.


Rick,

You may be letting it cool too much. According to Steve's instructions, you don't let it cool to the point that the nitrate would start to recrystalize.


Lazersteve said:


> -Stir until Nitre is completely dissolved, let cool below boiling
> -SLOWLY add 56 mL conc (96%+) Sulfuric Acid to Hot Nitre solution while stirring, DON'T allow the solution to boil!
> -Allow solution to cool to room temp (DO NOT SKIP - VESSEL WILL SHATTER IF PUT ON ICE WHILE HOT!!!)


He came up with the amounts involved to create the strongest acid possible, so the nitrate solution is used hot to minimize the amount of water in the reaction.

Dave


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## Barren Realms 007 (Sep 27, 2014)

rickbb said:


> I hate to bring back old threads, but;
> 
> I'm using Steve's cold recipe for the first time. He states to boil 100 ml of water then stir in 202gm's of either potassium nitrate or 170gm's sodium nitrate, I'm using potassium. (Spectracide Stump Remover, MSDS says its 100% KNO3.)
> 
> ...



I haven't used potassium nitrate only sodium nitrate. You will get a lot of crystals as the solution cools down to ambient temperature and more will form when you cool it down to freezing as recomended. I would suggest you make twice of what you think you need so you can filter the liquid that you pour off after the solution has set freezing over night. A trick that you can use is to filter the crystals after it reaches ambient temperature then take the filtered liquid and freeze it then filter again.


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## rickbb (Sep 27, 2014)

Oh crap your right.  

I even have the recipe up on my laptop here in the shop and still only saw the "let cool to room" temp. But that's for AFTER I add the sulfuric.

My bad.

  

Maybe I need some remedial reading lessons. sigh.

EDIT: correct spelling and to add;

Thanks Dave, all good now. Have a nice bright dark yellow solution cooling off.


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## rickbb (Sep 27, 2014)

OK, I guess I did something wrong after all. The solution is not quite down to room temp yet and I have a large amount of precipitate in the bottom. It started out looking like crystals, long ice like formations. I broke them up and stirred it all and now it looks granular.

This after adding the sulfuric acid and letting cool.

What I did;

boil 200 ml of di water, while boiling stir in 404gm KNO3 until dissolved, turn heat down. 

When boiling stopped and solution was still hot and clear, slowly added 112ml concentrated sulfuric acid, stir and turn heat off. Stirred a few more times then let sit.

When I noticed some precipitate, checked temp and it was about 105F, I stirred and broke up the precipitate several more times. It's now just about room temp and I have granules of something up to the 300ml mark. 

Is this normal? From what I've read you get the precipitate after you freeze it, haven't seen any mention of it at room temp.

Here is a picture;

http://i24.photobucket.com/albums/c7/rickbb/20140927_181117.jpg




Edit: change pic link


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## Barren Realms 007 (Sep 27, 2014)

Looks normal just not as much crystals with sodium nitrate.


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## rickbb (Sep 27, 2014)

Thanks Barren,

After some gentle prodding from a nice fellow, (thanks Dave), I went back and re-read the posts and this time I realize that the answers to all my questions were right there in front of me.  (I blame that speed reading class I had in high school, spent too much time skimming and not enough time understanding.)

I just took the solution out of the freezer and poured off 125ml the rest of that beaker is white frozen solid crystals and granular salts.

I plan to let it melt overnight and filter it off tomorrow and re-freeze to see if any more is in there. I was using stump remover, perhaps it was not up to the task. I have some tech grade KNO3 I will try on my next batch.

Rick


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## Shark (Sep 27, 2014)

I have used Spectricide Stump Remover several times, and the second round seems to produce slightly better than the first. I prefer Sodium Nitrate, as it does form fewer crystals, and they seem to be a bit larger, and easier to filter out. Doing a twice filtered solution as Barren suggests helps. I place the first filtration in one container and the second in it's own container. I am not sure why I do this, as they both seem to work well. Your picture of the salts settled out look normal for a Potassium based nitric. I work with such small amounts of materials that I have never been able to justify the purchase of actual Nitric Acid, and have always used my home made variety and been pretty happy with it. The one thing I find is the slower I add the Sulfuric Acid, (with a lot of stirring), the better the Nitric Acid seems to be.


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## rickbb (Sep 30, 2014)

Just an update and a thanks to those that pointed out the obvious things I missed in reading the posts here.

I ran 2 batches and now have ~550ml of nitric. 

One batch with the stump remover made a very yellow liquid (~300ml), and a batch with tech grade from a lab supply company made a crystal clear liquid, (250ml).

I tested it with a small sliver of ~997 Au. At room temp the reaction was not visible. Even after 48 hours it had not dissolved, it was blackened, but mostly intact. I put some heat under it and the reaction was very clear and the sliver was gone in less than 5 minutes.

Maybe someday I'll invest in some hydrometers and graduated cylinders to measure the SP to find out the strength that I'm making but as long as I'm following a known recipe and it does the job that's what matters. (And I'm learning something to boot.)


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## joekbit (Oct 18, 2014)

Well, where is Steves' recipe? There are now 15 posts here, 1 is mine and none of them Steves'. The first post how he enjoyed the ease of making it :?:


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## jimdoc (Oct 18, 2014)

joekbit said:


> Well, where is Steves' recipe? There are now 15 posts here, 1 is mine and none of them Steves'



http://goldrefiningforum.com/phpBB3/viewtopic.php?f=60&t=14040&p=143214&hilit=nitric+recipe#p143214


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## joekbit (Oct 18, 2014)

jimdoc said:


> joekbit said:
> 
> 
> > Well, where is Steves' recipe? There are now 15 posts here, 1 is mine and none of them Steves'
> ...


Wow,,,lol,,,that was quick. I like that kind of service

Thanks
Joe


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## jimdoc (Oct 18, 2014)

joekbit said:


> jimdoc said:
> 
> 
> > joekbit said:
> ...



The search box is quicker.


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## joekbit (Jan 15, 2015)

Well I did my first batch with Steves recipe. Went well. I used NaNO3. I see at least 1 person ran the salts a second time, so I did the same. Not sure how it will come out right now, it's in the freezer. Any idea on just how many times you can use the salts? That would be nice to know. How can we tell if we have exhausted all the nitrate in the salts?

Corrected mistake, had NaNO2 now NaNO3


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## butcher (Jan 15, 2015)

Using the recipe properly you will not have nitrate salts left to reuse, Laser Steve done a good job of calculating moles needed for the reaction and conversion, your salts would be sulfate salts (that could possibly hold some trapped nitric acid depending on how you performed the reaction, a little water will pick up any trapped nitric acid), the sulfate salts can be reused in other chemical reactions where you may need sulfates.

Reusing the sulfate salts they cannot be used again to make nitric acid.

Unless you made bisulfate, from using too concentrated sulfuric acid, and less nitrate salt in your reaction, then it has a hydrogen that can act similar to sulfuric in a chemical reaction.

I am not sure what you mean by reusing your salt, but if you do not have sodium bisulfate NaHSO4, and have sodium bisulfate Na2SO4 as a byproduct, you cannot reuse it to make more nitric, at least not the way I think you may be trying to.


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## joekbit (Jan 16, 2015)

butcher said:


> Using the recipe properly you will not have nitrate salts left to reuse, Laser Steve done a good job of calculating moles needed for the reaction and conversion, your salts would be sulfate salts (that could possibly hold some trapped nitric acid depending on how you performed the reaction, a little water will pick up any trapped nitric acid), the sulfate salts can be reused in other chemical reactions where you may need sulfates.
> 
> Reusing the sulfate salts they cannot be used again to make nitric acid.
> 
> ...



I had a mistake in my post NaNO2 was changed. I took the salts that settled from the first batch (Steves cold nitric), added 100ml H20 and heated, not to boiling, just until the salts dissolved. I then added another 56ml concentrated H2SO4. stirring it, after it cooled I put it in my freezer 4 hours then decanted. That batch yielded more than the first and was far more reactive. Likely it is a bit more dilute causing it to react very fast on copper. I put a few drops from the second batch in my solution and the reaction scared me, I thought it was going to boil over. The nitric from the first batch was no where near as reactive

In any event I love the recipe.


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## butcher (Jan 16, 2015)

Sodium Nitrate is NaNO3, and can easily be used to make nitric acid.
Sodium Nitrite is NaNO2, although you can make nitric acid from it, is not as easily done, (the nitrite needs to be oxidized to nitrate before you could make nitric acid with it).

You probably were using nitrate NO3- (sodium nitrate) in your recipe. (nitrite would not have worked as you discribed).

Small details like the I or A in the spelling (nitrate or nitrite), or the number of oxygen's (NO3 or NO2) make a big difference in chemistry, you really need to pay attention to these small details.

Like in our last discussion where we discussed sulfate salts, Na2SO4 (sodium sulfate) and NaHSO4 (sodium bisulfate), where the name is only slightly different and the formula only slightly different, but how they react in a chemical reaction can be very different, where one could react as an acid, like sulfuric acid, with its hydrogen, in a chemical reaction.

I am not sure, but you probably did not get a good conversion, (trying to make it stronger) without the needed water to dissolve the salts properly for the sulfuric to react with, or using the wrong proportions or get a good conversion, or did not get the salts dissolved well enough for complete conversion from the mechanical process of your experiment...

if making cold nitric acid using Laser Steve's method following his instructions and quantity's will work well, changing the formula or how the reaction is done, will not make it properly, (like trying to make it stronger with this method), would not work. there are different methods to make stronger nitric acid, but they are not needed in recovery and refining, if you need it stronger or purer, using Steve's recipe, and distilling for purity, and evaporation of the approximate 50% to 68%, will work best in what we do, (or diluting your nitric when needed for base metals, making it easier to react with these metals).

Stronger is not always better.


You can also make nitric acid using more water, or a more dilute sulfuric acid, and get a good (weaker) nitric acid (which is not a problem when you use heat to dissolve metals), in fact it can even be better as less NOx gases are formed and less of your nitric acid is wasted).

For homemade nitric acid using the cold nitric acid method, water is an important part of the reaction.


In this science we really need to pay attention to the small details, they really make a difference.


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## necromancer (Jan 16, 2015)

i love this post, my problem is that i am in canada & i do not think i can buy it here

stated here http://www.nrcan.gc.ca/explosives/restricted-components/9981 i am not sure if i can order it from the USA without having it confiscated by customs.

has anyone in canada found "Sodium Nitrate" (NaNO3) in canada or had it shipped to canada ??

thanks in advance


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## butcher (Jan 16, 2015)

I do not know your laws or rules there, but if you are not making or selling nitrates or nitric for making explosives maybe you can get it by following the rules or law for refining?

Have you studied the law or rules?

It would seem very strange to me if I could not make my own fertilizer and use it to recover a metal.
If I was not harming anyone.
Now the government wanting some of it as a tax, control purpose, to keep others safe from some idiot, or to gather the nitrate for a nations defense purposes, I can easily see, as this has always been done in history.

Surely it is not illegal to buy and use fertilizer, or for an industry to use chemicals.
Making and using explosives is another subject all together.
Do you not have guns in Canada? Can you buy bullets for your gun, if you follow the law? 

Maybe you need another country, or work to change yours if things are that bad there, where you could be in big trouble if caught gathering the white crystals from your barn walls, and dissolving copper with them.


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## necromancer (Jan 16, 2015)

butcher said:


> I do not know your laws or rules there, but if you are not making or selling nitrates or nitric for making explosives maybe you can get it by following the rules or law for refining?
> 
> Have you studied the law or rules?
> 
> ...




i have read that it's also used for curing meats. i still cant find it.
companies i have emailed that supply meat curing items only sell it mixed with salt & spices. i am going to go to a large meat curing manufacture next week to see if they have it. there 10 minutes away, thinking if i go to the receiving area & ask to speak to a supervisor i may find it ??

it's all worth a try

there is also this document:
http://www.nrcan.gc.ca/sites/www.nr...pdf/expl-expl/13-1057_Chemicals_Concern_e.pdf

today i will email the Ministry of Natural Resources Canada, Explosives Regulatory Division.
hope they don't come kicking down my door :x


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## rickbb (Jan 16, 2015)

Since this post is about making your own, I've found this;

http://www.instructables.com/id/How-to-Make-Sodium-Nitrate-A-Potassium-Nitrate-Su/


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## necromancer (Jan 16, 2015)

rickbb said:


> Since this post is about making your own, I've found this;
> 
> http://www.instructables.com/id/How-to-Make-Sodium-Nitrate-A-Potassium-Nitrate-Su/



thanks, i will have to start reading labels, wish i was a farmer  

strange thing is, i can find the address of storage facility's where they store 200 tones or more in canada (50km from my home)
but i can not find a place to buy it.

http://globalnews.ca/news/492924/ammonium-nitrate-in-canada-locations-and-regulations/


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## necromancer (Jan 16, 2015)

also found this.
http://chemistry.about.com/od/makechemicalsyourself/a/make-ammonium-nitrate.htm


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## necromancer (Jan 16, 2015)

i feel that i should start at square one again.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=315&start=100#p104689

going to try get some "sodium nitrate" or "potassium nitrate" i made an agreement with the landlord of my shop, he said ""no ammonia in my building""

i have to respect him, he is a great guy & lets me get away with murder 8) . the agreement was because of it's use during world war 2


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## jason_recliner (Jan 16, 2015)

rickbb said:


> Since this post is about making your own, I've found this;
> 
> http://www.instructables.com/id/How-to-Make-Sodium-Nitrate-A-Potassium-Nitrate-Su/


Of all the awful hurt-yourself videos on Youtube, Nurdrage is one chemist that seems professional and legit enough to trust and follow.
I've used the coldpack method recipe to make my sodium nitrate. It's just as easy for beginners as is using too much acid.


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## joekbit (Jan 16, 2015)

butcher said:


> Sodium Nitrate is NaNO3, and can easily be used to make nitric acid.
> Sodium Nitrite is NaNO2, although you can make nitric acid from it, is not as easily done, (the nitrite needs to be oxidized to nitrate before you could make nitric acid with it).
> 
> You probably were using nitrate NO3- (sodium nitrate) in your recipe. (nitrite would not have worked as you discribed).
> ...



yes I was, I double checked (nitrate) pellets, purchased from the science company. 99% about $6 USD

Doing some research, I found out it was shipped by Rocky Mountain Reagents. I went to their site and found 70% nitric, 2.2l for about $50 USD, but, as best as I can tell you need to call to place an order. So I am going to call them. Need some good nitric for AR solutions.


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## Geo (Jan 19, 2015)

joekbit said:


> Need some good nitric for AR solutions.



Any solid nitrate can be substituted for nitric acid in an AR dissolution. For the dissolution to work properly, the solution needs extra water and to be heated. Just the temperature of steaming water will work. Add the solid nitrate as you would nitric acid, slowly and in increments. The reaction Involves the nitrate dissolving the metal and in doing this evolves NOx which is absorbed by the water making nitric acid in solution. It's not something that happens in steps, it happens almost instantaneously. It reacts exactly like nitric acid.

Most people needs nitric acid when dealing with silver. Using solid nitrates is a work around for those that can't source nitric acid. It's the first AR dissolution that I ever processed. It's something that, as a refiner, you will need to master along with other work around methods.


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## joekbit (Jan 22, 2015)

Geo said:


> joekbit said:
> 
> 
> > Need some good nitric for AR solutions.
> ...



Thank you very much Geo. It has been my observation that it is true, but you just answered the question I never asked. I have added solid NANO3 to solutions with just a bit of H2O as well, and noticed copper being dissolved and the usual brown nitrate gas being emitted. What I have done to prolong the reaction is placed another beaker into the solution beaker, with my hot plate on warm, then put cold water into the inner beaker. While watching I noticed with every drop of condensation that falls off the inner beaker the reaction gets more violent / or better. Eventually it will quit but the recycle through condensation helps a lot.

Correct me if I am wrong, the brown fumes are the NOx, the condensation captures the NOx creating weak nitric acid, as it drips back into the solution the cycle goes on. Yes or No? My reasoning tells me yes.


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## Geo (Jan 22, 2015)

Your assumptions are correct. There is actually many ways of capturing the nitrogen dioxide and returning it to the reaction. A watch glass for a beaker works pretty good. There is glassware made for the job called a "reflux condenser". Since I do my first dissolution in coffee pots, I have found what seems like a mated pair that the bottom of one fits perfectly on top of the other. I fill the top one with ice and sit it on top of the reaction and it collects almost all of the brown-red fumes.


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