Making poormans Nitric Acid

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oldtimmer

oldtimmer

Well-known member
Joined
Jan 31, 2009
Messages
107
Location
San Diego Ca
Finally ready to run several pounds of CPUs in the poormans Nitric acid.

In my notes all I can find is a small post it note:

1 Lb Sodium Nitrate
1 qt. Sulfuric Acid (battery acid)
1 cup hot distilled water (to disolve the Sodium Nitate).

I was wanting to verify that this is correct before I ended up making a big mess of things. How long do I need to let it set before I pour it on the CPUs?

Thanks,

dave
 
Dave,

The amount of sodium nitrate sounds a little high to me. I made a spreadsheet for all the various concentrations of sulfuric acid verse the weight of sodium nitrate needed. I'll try to dig it up and post it. You'll need to get all the sodium nitrate into solution for maximum conversion of the nitrate to nitric.

After the nitric goes into solution the sodium sulfate must be separated from the dilute nitric acid. Cooling the mixture to below 0C for several hours helps facilitate the sulfate precipitation.

Steve
 
LazerSteve:

After you finish with the sodium sulfate, is there any use that it can used for, other than just disposing of it?

Thanks in advance.
 
Here's a method for nitric that I postulated may work, but I have never tried it.:

Everything but the squeal nitric

I'm sure you will have some losses along the way and the yields won't be exact but it's more of a theory than a tried and tested reaction. If you try it out let us know.

Lou has stated that Na2SO4 is not favored in the reaction, instead NaHSO4 is the by product. If this is the case you can combine NaHSO4 dry with just about any sodium salt of an acid and distill out the acid.

Steve
 
lazersteve said:
Dave,

I made a spreadsheet for all the various concentrations of sulfuric acid verse the weight of sodium nitrate needed. I'll try to dig it up and post it.
Steve
Click to expand...

I missed than somewhere along the way.
Please do post it Steve.
 
lazersteve:

I'm using your nitric recipe to make poormans nitric.
100ml boiling distilled H2O, Add and stir to disolve,
170 grams Nitrate of Soda (Bonide brand), slowly add to prevent foaming,
50ml conct H2SO4 (Rooto Drain Cleaner brand), Chill to precipitate salt.

What I'm asking is what can I do with the salt cake that is left after the reaction? Is there anything that it can be reused for or is it just a waste product to dispose of?

Thanks for your help.
 
Lazersteve:

Ok that means I need to find calcium nitrate, but at least I get to reuse the salt and don't need to find a way to dispose of it.

Just trying to reuse everything to keep disposal and waste to a minimum.

Thanks
 
Hey oldtimmer,

The recipe I was given and use is for 1 cup of sodium nitrate dissolved in water
for an hour then you add one quart of H2SO4 and let it sit overnight. Pour off
the clear liquid leaving behind any undissolved sodium nitrate.

It seems to work for me. 8)
 
LazerSteve: Am I missing something? You indicate that you concentrate napa battery acid (33%) to get 98% by boiling it down, then you add 100 mL of water and 56 mL of 98% sulfuric acid to 170 g sodium nitrate. Why not make it simpler, add 168 mL of 33% sulfuric acid to 183 g sodium nitrate? I tried this last night, and it dissolves in about 10 minutes with a little warming. Also, letting it cool completely, then about 45 minutes in the freezer gave hard-packed crystals and the solution decanted clear.

Prospector
 
The water is used to dissolve the nitrate before adding the concentrated sulfuric. Adding the solid sodium nitrate to 35% sulfuric may also partially work, but will not guaranteed the nitrate is dissolved and thereby fully converted by the sulfuric to nitric acid. Any nitrate that fails to dissolve in the dilute sulfuric acid will not be converted to nitric acid and will remain as a white mass of sodium nitrate.

By putting the nitrate into solution first, you are assured that the bulk of the precipitate is sodium sulfate, not a mix of sodium sulfate and sodium nitrate.

The order of dissolving the nitrate first, then adding concentrated sulfuric acid assures you do not have any crystals of un-reacted sodium nitrate in the mix. As a test try dissolving 170 grams of sodium nitrate in 100 mL of water and you will see that it is very hard to get the nitrate into liquid form where it can be converted by the sulfuric acid.

Another test would be to heat a small sample of the left over salt. If you see brown fumes you did not convert all of the sodium nitrate.

Steve
 
Thanks, lasersteve. Actually, with the increased volume, all of the sodium nitrate dissolves faster in the 33% sulfuric acid than in 100 mL of water. There are no crystals remaining prior to the freezer step.

By the way, your responses are invaluable to many of us, and your website is awesome!

Prospector
 
As long as all of the salts become soluble before the freezer step you are on the right track.

I could not help but notice that you mentioned you are using more volume and calculated that the 168 mL of 33% acid would indeed contain ~112 mL of water which would produce a slightly weaker acid and actually be an 12% increase in the volume of water used. This extra water would also serve to hold slightly more sodium sulfate in the solution even when cold. This would also explain how you are able to get the sodium nitrate to fully dissolve at the lower temperature.

Have you tried this with calcium nitrate?

Steve
 
I tried with calcium nitrate, it makes one heck of a tooth paste (not for teeth) real pasty and thick, no cooling needed, centrifuge is.

Jim
 
Steve / OldTimmer,

When I first started learning about refining, the guy I purchased some chemicals from told me the resulting preciptant from the sulphuric and sodium nitrate, apparently Sodium Sulphate, could most likely be used to precipitate gold from pregnant solutions. I have presented this on another topic before. I believe you know the person Steve as you thought he was a member of this site Dr.Goldman-on Ebay, or Dr.Charles-on the Forum?

What Say you Steve? Will it precipitate Gold, will it do it as selectively as SMB?

Thanks Guys,

Nick
 
Nick,

I've never tried it but seriously doubt it will work under normal circumstances. Sulfite is required, not sulfate.

Steve
 

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