# Concentrate Nitric Acid ?



## Noxx

Hello,
Is there a way to concentrate my nitric acid without distillation ?
I made it with with Sulfuric acid and Potassium Nitrate. Final product is about 30% Nitric.
Thanks


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## lazersteve

Have you cooled the solution down to below zero degress C and filtered? This will help drop out as much salt as possible leaving you with more nitric acid in the solution. The only other way that I know is careful distillation.






Steve


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## Noxx

Yes, I cooled it unden 0°C.
Do you have good websites explaining how to distillate ?
I have most of the appartus needed, I just don't have the right tubing. I suppose I can't use vinyl tubes with rubber stoppers...
Thanks


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## goldsilverpro

I now think I know the reasons for your nitric acid questions on the gold testing thread. Do you plan on using your homemade nitric to test the gold you are buying? This could be a big mistake. Buying gold is an area you don't want to make mistakes in. Using this Mickey Mouse nitric puts another big variable into the mix. If you're just playing around or just have a pioneer spirit, that's one thing. When you put hard earned cash out for questionable gold, that's another thing. If you can't find good nitric, order some bottles of testing solutions from eBay or, better still, from a jeweler's supply company. They're only about $3 per bottle.


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## Noxx

I taught I could use my own but then I realised I need good quality nitric. But no I won't use it for testing. I'm having hard time dissolving copper mixed with gold. My acid is too weak and doesn't dissolve it much...
Thanks


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## toadiesop

I bought 22K testing solution from ebay.. I kinda looks like AR (it just might be. The label says "contains HCL and Nitric Acid")

I've been testing everything for the sheer fun of it ... :lol: 

I paid $5 with shipping for it, so I'd say def. buy the stuff instead of trying to make it.

The only reason I bought it was because I bought it at the same time as all the other chems for AR and I wanted to know when I got at least 22K out of my batches.

There was a full set of testers for $15 the last time I checked. (10,12,14,18,22,24)

I'd say that is the best bet until you are confident you can make it. I know I'm not there yet, but hopefully someday I'll get there. In the meantime, I'll just pay for what I know to be perfect and concentrate on other things. 

I hope that made sense.


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## goldsilverpro

Good info, toadiesop. I think I also saw a platinum test solution, a while back, on eBay. The $15 six pack is a good deal.


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## PhillipJ

> Have you cooled the solution down to below zero degress C and filtered? This will help drop out as much salt as possible leaving you with more nitric acid in the solution. The only other way that I know is careful distillation.



Like Noxx, I too make nitric from sodium nitrate and 33/100 battery acid. I have a lab still & tried to still it off. Nothing happened at 83C (boiling point of nitric acid) The condenser didn't even get wet untill untill I slowly raised the temp to 100C and got the water to boil.

I am boiling off some battery acid (without the sodium nitrate) right now to use in Steve's recovery cell I'm putting together. But I would like to know the trick to getting nitric acid to come out of the dumb thing.

Battery acid is cheap at NAPA. Last time was $11 something for 5 gallons.


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## PhillipJ

LMOA. I'll figure this message thing out someday. The quote part.


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## goldsilverpro

I've done 180 posts and I still can't figure it out. Especially the quote in a quote in a quote.


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## lazersteve

Phillip,

It may make more sense if you knew that the information quoted was nearly the last step in a multistage procedure. I had already discussed this with Noxx in a PM a while back.

The reduced temperature will force any dissolved niter salts to precipitate out of the solution as sulfates leaving the nitrate portion of the molecule behind. It stands to reason that if an ion is dissolved in a solution the acidic molecule it is bond to won't be free to form the desired acid. 

Here's a solubility chart that I calculated the reaction around:






The idea was to dissolve the nitrate in the minimum amount of warm water, cool to room temp, add the sulfuric acid, then bring the solution temperature down to drop the least soluble salt. What remains is a small quantity of the original nitrate in dilute nitric acid with a touch of the resultant salt.

Steve


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## goldsilverpro

A crazy idea - maybe.

I spent a couple of years experimenting with ion exchange membrane cells. They are basically ion traffic controllers. You can buy membranes that only pass negative ions or, those that only pass positive ions or, those that pass no ions, etc. In the Shor refining machine, I think he uses one of these membranes. It's in one of his patents.

I've worked out a way to make pure nitric plus water with a membrane cell. It's basically 3 or 4 inline plastic chambers, with membranes in between, and electrodes in the end chambers. The chambers all contain liquids. 

Sodium nitrate is in one chamber. The nitrate part of the sodium nitrate is pulled into another chamber by the current. The hydrogen ion generated at the anode is also pulled into the same chamber from the opposite direction. The result is H+NO3 - Nitric acid. 

They use these things for desalinization. The Na+ and the Cl- are pulled out of the water, to other chambers, in different directions.

I know that this will work from past experiences. No doubt. It can be made to any strength. The longer it's on, the stronger it gets. The problem is in finding a membrane that will stand up to strong nitric. I'm still looking. I may be able to use a flower pot with the hole sealed up. The old fizzer cells, which were membrane cells for making gold chloride with strong HCl and current, used unglazed clay pots as the membrane.

This would be very cheap to set up. The biggest cost would be the power supply.


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## goldsilverpro

I'm still studying your chart. Good job. You've been busy in the CRC Handbook, it looks like.

Sorry Steve. I started typing my long post before you posted your great chart. I didn't mean to rain of your parade.

I'm now reading my Chemical Dictionary on how they make nitric acid. One of the methods sounds interesting. They start with weak nitric acid. This is neutralized with soda ash, evaporated to dryness, and treated with sulfuric acid. Synthetic niter cake - NaHSO4 - precipitates out as a by product and, I guess you're left with conc. HNO3. I'll work out the equations. Sounds simple and cheap.

*WOW! * I just caught on!

The more I read this, the more I realize that it's *EXACTLY* the same process you're working on, Steve! You're starting with sodium nitrate. They're making sodium nitrate in the first step. Everything else sounds the same. The only difference is that they add the H2SO4 to DRY sodium nitrate. Wouldn't this be better? Wouldn't you end up with stronger nitric? May I ask where you got your process? Does this process have a name? I love this process. This is very exciting.

If you were to use concentrated sulfuric, not drain cleaner, and dry sodium nitrate, there would essentially be no water in the system. You might end up with red fuming nitric, which wouldn't be good. To make 68%-70% nitric, by weight, which is about tech. grade strength, you would have to add some water somewhere. Have you done the equations? 

To get out most all of the salt, you're chilling it. The process in the book gets it all out by having a non-water system. The salt is NaHSO4, sodium bisulfate, which, to have excellent nitric, you must get rid of. There must be a middle ground. Terribly exciting. Have you tried this?

Ideally, the way to do it would be to make it without water, to get rid of all the salt, and then dilute. However, the red fuming nitric might drive you out of the building, or the county. 

Have you posted any other info about this on the forum? I think you have. Can you find it and give links. I didn't pay much attention because I thought it was a distillation process you were talking about, which I hate. I apologize.


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## lazersteve

Chris, 

It came from the space between my ears! :lol: 

I have not tried it yet. It's something I cooked up for Noxx last month in a PM. When he replied about his success I realized he took some shortcuts and made a few measurement errors (no offense Noxx :wink:, you did great ). I had considered going dry but you've already pointed out the pitfalls of that idea. The idea is to use the least amount of H2O to dissolve the niter. This is accomplished by temperature control, hence the chart. Yes, I've done the math on this one. No it hasn't been made public.

Steve


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## PhillipJ

Not understand all the chemistry you guys are talking. The girls, I understood back when I should have been paying more attention to education. Now I'm paying!

ANyhow. I stilled off some sulfhuric acid. "no more water." I added sodium nitrate pellets. They did not dissolve, even when heated. I had to add it to a little of the water I stilled off, and heat, to dissolve the pellets. The pellets made heat when mixing. It is no where near "Red Fuming"

It will eat metals, but could be a lot better.

From what I gather here is to now freeze it, and filter it.

At what point do I plug the cord in? :roll:


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## goldsilverpro

Steve,

Here's the equation:

NaNO3 + H2SO4 = NaHSO4 + HNO3

Here's the weights in grams, rounded off, for the reaction to produce 1 liter of 70% nitric acid. This assumes that everything is anhydrous which, of course, it isn't. I have included the 30% water in the nitric on both sides. More water than this will be needed to dissolve the NaNO3 so, the nitric % will be less. Also, there's water in the sulfuric to consider.

1330(NaNO3) + 1533(H2SO4) + 422(H2O) = 1878(NaHSO4) + 986(HNO3) + 422(H2O)

One liter of 70% nitric weighs about 986 + 422 = 1408 grams

The salt, NaHSO4, sodium bisulfate, is strongly acidic when dissolved. It's used for toilet cleaners (Sani-Flush is 75% NaHSO4), lowering the pH of swimming pools, a safer sulfuric substitute in school labs, and an acid pickle for silver castings.

NaHSO4 is very soluble in water, even at 0 deg C. Here's the solubilities: 500 gm/L at 0 C., 670 gm/L at 22 C., and 1000 gm/L at 100 C. If you plot those out, it curves down to the left and seems to hit zero at about -80 C. This happens to be the temp. of dry ice. It seems like, if you used dry ice, you could get all of the salt out. The problem is, nitric freezes about -42 C. and, this figure is probably for 100% nitric. For 70%, it would be higher. There is most likely a low temp to maximize salt dropout without the nitric freezing. You could use a thermometer. 

On the net, with the little amount of info that I could find on the process you're doing, they required distillation to get rid of the salt. Of course, they didn't think about chilling it.

The solubilities, above, are for the salt dissolved in water. In the presence of the high nitric acid, the solubilities might be a lot less.

All in all, we don't need 70% nitric acid for most any of our processes. For dissolving silver, copper, etc., a 50/50, nitric/water, mix of commercial 70% nitric, cut by volume, is the most efficient mix for dissolving. This figures out to 41% nitric by weight. For aqua regia, I usually add about 10% water, for effeciency. I could use a weaker nitric, add no water, and end up with the same thing. The nitric for this purpose would be about 53%, by weight, assuming a 3/1, HCl/HNO3 mix.

Also, if the nitric % is high enough, the presence of some of the salt in the solution might not interfere much with our processes. This would require experiments.

I downloaded a couple of old industrial chemical books on Google Books. I found another process. Instead of sodium nitrate, they used barium nitrate. The equation, otherwise, is about the same. It takes about 1.5 times as much weight of Ba(NO3)2 as it does NaNO3. The big difference is that Ba(NO3)2 is only about 10% as soluble in water as NaNO3. Therefore, the nitric yield was only about 10%, by weight. They said you could boil it to raise it to 25%, the point at which HNO3 starts coming off. The 25% would work for our processes but, not as fast. The beauty of using Ba(NO3)2 is that the resulting salt, BaSO4, is zero soluble in everthing and, therefore, could be completely removed at room temp. About the cheapest I found barium nitrate was from pyrotechnic chemical companies, for about $3.30/pound. That was for one pound quantities. They couldn't ship it, so you had to pick it up.

Steve, unless I made mistakes, those are the numbers. I wish I had a lab but, I don't. If you need help or advice, I'm here. Please keep us posted with your progress. As you know, this process could be very important to all the members that can't get nitric acid.


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## goldsilverpro

Sorry about all the chemistry talk, PhillipJ. Steve's process could be very important to all members and, we have to get the numbers right. When finished, the process will be much simpler.


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## PhillipJ

Ya hey. I knew you 2's were cyphering up a good recipe.


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## Noxx

Barium is a good idea. But Barium salts are VERY toxic. Also, it's also impossible to get it here...


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## jimdoc

Here is a link to platinuminfo about nitric acid making.
http://www.platinuminfo.net/app_ind_na.html
maybe there will be something in what they say that will
help. They say platinum or rhodium gauze is used in the
Ostwald process.
I don't understand all the chemistry talk, but cheap or even
available nitric would be a help to all of us, so thanks guys.
Jim


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## lazersteve

Chris,

Nothing appears wrong with yours a first glance, except in mine I'm not leaving any Hydrogen behind as follows:

H2SO4 + 2 NaNO3 --> Na2SO4 + 2HNO3

The big difference in my recipe is the solubility of the sodium sulfate salt (as opposed to sodium hydrogen sulfate you produce) and the fact that my equation yields twice the nitric acid at a higher temperature ( no dry ice, just salted ice ). :wink: 

I've run the numbers like you did and ended up with about 160 mL of 50% nitric (give or take a few percent) for a single mole of 96% sulfuric and using 100mL H2O to dissolve the nitre.

I won't bore everyone with the math, but here's my summary (PM me to see all the factors I used to derive this reaction):







Reaction:

-Bring 100 mL of Distilled Water in a 500 mL pyrex beaker to 100 C
-Add the Nitre of your choice (202 gm K / 170 gm Na)
-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!!!)
-When vessel reaches room temp (25 °C) put the vessel in the freezer or on a salt water ice bath
-Let stand until temperature of mixture reaches -5 °C
-Let stand at -5 °C until all precipitate settles
-Pour the COLD solution off into glass container with tightly sealed lid DO NOT POUR OFF ANY OF THE SALT IN THE BOTTOM!!!
-Makes ~160 mL ~50% HNO3






Steve


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## lazersteve

Here's a very interesting tidbit I just noticed on wiki while reviewing the sodium sulfate salt produced by the above reaction:

http://en.wikipedia.org/wiki/Sodium_sulfate#Other_applications

Pay very close attention to the last paragraph of this section (Other Applications). We may have an excellent processing cycle in the works here. One that may even allow us to recycle the by products for reuse. :idea: 

Steve


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## goldsilverpro

They both are valid equations and both are reactions of the same 2 starting chemicals. The quantities of the 2 chemicals is what makes the difference. You went in one direction and I went in the other. I don't think either of us realized the other direction existed. I know I didn't.

However, to produce all Na2SO4, the quantities of H2SO4 and NaNO3 must either be perfect or short on sulfuric. If any extra H2SO4 is present, it seems the NaHSO4 will form, as in the Wiki link you just gave. Check the first equation under "Physical and Chemical Properties", near the top. Do you read this the same way?

I notice that you are using conc. H2SO4. What about using the drain cleaner? It would be touchy but it could be done. You need a method of analyzing the drain cleaner. This could be done in a few minutes with a scale and a small vessel to measure some sulfuric fairly accurately. An inexpensive graduated cylinder would be good. Measure the sulfuric out accurately, weigh it and calculate the density. Look the answer up on a chart and it tells you the concentration. You could easily get within 1%-2% accuracy.

Of course, making sodium sulfate would be better than making sodium bisulfate.


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## lazersteve

Exactly how I read it as well.


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## goldsilverpro

Read my post again. I added to it.


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## lazersteve

I merely specified the percentage to set a reference point for the molar calculations. Any concentration above 90% would be fine, you just need to adjust the input volume. The extra water can begin to dilute the product if you go much lower in concentration. Luckily sulfuric is the easiest of the mineral acids to concentrate!

Steve


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## catfish

Hi Steve:

A great piece of work on comming up with a safe and easy method that us neophytes can make an acceptable Nitric Acid.

I just read this post last night and decided to try to make a batch of Nitric acid with this formula.

I made a batch today with good results. The only difference was, I came up with a different total amount of nitric acid. After taking it down to approximately -5c. and carefully pouring off all liquid, I wound up with 130 ml. I may have poured it off too quick.

I immediately poured some on some small semi-gold plated pins and the acid went to work immediately. In just a short time it had disolved all of the non gold metals.

I have been making a very weak nitric acid with concentrated sulfuric acid and sodium nitrate by letting it sit over night and pouring it off.. There was always about half the sodium nitrate left and the resultant acid was very weak. It took several days to disolve small gold pins. 

Your method and formula is certainly appreciated and as always, thanks again for your many contributions to this forum.

I have an old say "Nothing happens accidentally"

Thanks again,

Catfish

PS Thanks to Cris for his input also.


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## lazersteve

Catfish,

Thanks for the feedback, I'm glad it worked for you. Did you use Potassium Nitrate or Sodium Nitrate?

This would have been a great tutorial, you may have been the contest winner had you entered it as a tutorial, it's not too late.
:wink: 
Steve


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## catfish

Steve:

I used Sodium Nitrate (16%) and contcentrated sulfuric acid (battery acid from NAPA) that I boilded down to Specific Gravity of 1.8 Grams per 1 ML. I found that commerical battery acid is 65% H2O and 35% of 98% Concentrated H2SO4. I measured the SG of the the Battery acid and found it to be 1.25 SG and then boiled 1000 ml of the battery acid down to 360 ML and remeasured the SG and it came out to be 1.80 SG per 1 ml. 1.84 sp per 1ml at 25`C would have been 98%. Unfortunately I dont have any specilized laboratory equipment for precise measuring of the specific gravity and concentration precentage of this H2SO4, but my calculations puts it in the 90+ % range.

I have been using this acid in my Electrolytic cell. It is absolutely clear, no special additives or inhibitors, and works extremly good.

Keep up the good work Steve. I enjoy reading all your posts and find not only do they make interesting reading, but are also very informative. Steve, too often we see folks that are extremly knowledgeable but do not possess the verbal or written skills to explain thier ideals. You have a very good understanding of gold recovery and refining principals and technical theory. You are also very good at being able to convery your thoughts and ideas to others in layman terms to us neophytes, inorder that we not only understand them, but we can put them to practical use.

Thanks again,

Catfish


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## lazersteve

All,

I put my thinking cap on at lunch today and fine tuned my original nitric acid recipie from yesterday's post. I'm running the numbers one more time and will be posting a new and improved, never before seen, version of the experiment. The chemicals are readily available, safe, and the reaction produces a product that is more concentrated than the previous version of the experiment. Stay tuned gold diggers!

Catfish,

Thank you for the kind words, they make my efforts all that much more rewarding!


Steve


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## goldsilverpro

Catfish and everyone else,

How long did it take to boil down the battery acid? Did you actually boil it? If you did, I'm sure you noticed that, the stronger it got, the higher the boiling point. In fact, 98.3% sulfuric acid, by weight, boils at 640 deg. F. I can't imagine anything more dangerous than 640 degree concentrated sulfuric. Since the sulfuric holds the heat, it's easy to let the temp. rise that high, on a regular hotplate. Be extremely careful. Rethink how strong you want to get this stuff and how hot you want to get the temp. At a lower temp., it will take a lot longer but, will be safer.

Put the vessel that you're heating the sulfuric in, inside of a larger heatproof container, in case of breakage or spills. The best arrangement I can think of is a beaker inside of a 5 quart, white, flat-bottomed, Corning Ware dish. Of course, you don't need the lid.

Also, around 98%, you start giving off sulfur dioxide fumes. Did you smell this?

I've done a lot of what's called "wet ashing", using very hot concentrated sulfuric. This is used to dissolve organic materials (think skin). For example, I used it for vacuum filter papers that had small quantities of gold powder stuck to them. The wet ashing totally dissolved the paper, leaving a clear solution with the gold powder on the bottom. This was for assay purposes and not for refining. I have also dissolved a few dead flies, grasshoppers, etc., in my life. BTW, this is very dangerous and I haven't told you the whole procedure because I don't want you trying it. It won't work as I gave it. I'm just trying to illustrate the dangers of hot strong sulfuric.


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## catfish

Goldsilverpro:

You are absolutely correct about the boiling temp of H2SO4, My book sez 338C or 640.4F at 98.3%.

I heat the NAPA battery acid in a pyrex bowl on a hot plate out side. I also place the hot plate and all in a foot tub in case of breakage. (this also keeps the wind from effecting the heat) I heat the H2SO4 at 230` F with a good quality thermometer, monitoring the temp at all times. My objective is to reduce the h20 only. When I start this process, I weigh 1.0 ml of battery acid in 10 ml test tube on my gold scales after zeroing the scale with an empty test tube. I also then weigh 1 ml of distilled water and determine the Specific gravity of it which always comes out to be 1.0 SG. I always come up with 1.20 to 1.25 SG on NAPA battery acid. This is about 65% h2o and 35% H2SO4. Keep in mind I dont have a pycnometer to a be able to make a precise measurement. But this is close enough for me. Also I don't crank in the temp correction factor of .0023.

It takes me about 1 hour to boil off the required amount of water. At 230 degrees it will eventually stop boiling and condensing. There are never any odors that come from this process. After it cools to room temp, I then take 1 ml again and weigh on gold scales. It just about always comes up to 1.8 + or - .1, specific gravity. Keep in mind my scale has a + or - accuraticy of .1 gram. I then measure the volume of the remaining acid and it usually comes out to about 360 ml + or - 10ml, when I do a 1000ml in a batch.

I have done several different batches of different volumes and they all come out the same. Just the boiling times are different. I have no way to actually measure the precent of concentration of the remaining sulfuric acid. All I can do is determine the approximate precent computation by using the formula of 1.84 SG at 98.3% concentration., and do the math to come up with my precentage of concentration.

You have heard the term, " necessity is the motherhod of invention". Well I dont like all the additives and inhibitors in the drain cleaners and this is the reason I came up with this method. I buy the NAPA battery acid for $4.80 plus tax for 1.5 gallons. This will make about 2 quarts of pure 90+ % concentrated sulfuric acid for my cell and to make Nitric acid. 

Catfish


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## goldsilverpro

Catfish,

I think your method is excellent, very well thought out, and scientific, yet practical. You call yourself an amateur but, I think you are underrating yourself and your method of approach could teach us all a thing or two. Steve is right, you should do a tutorial on this. It could very well win.


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## PhillipJ

Catfish. You seem to think a lot like I do. Except I boil my acid in a lab still on a gas stove on low flame. It takes maybe 12 hours to get all the water off. I can tell it's done when the condenser shows few droplets. What goes in the catch jug makes a unique flavored coffee.

I tried making nitric acid with drain cleaner and found that it is best left as drain cleaner. The NAPA acid is good stuff and even cheaper in the 5 gallon jug they sell.

Haven't tried Lazer's recipe out on anything yet and am hoping it works better then the old way of just pouring the 33/100 sulphuric acid on NaNO3. When doing pins, the copper chrystals formed and clogged the whole works up and I had to add hot water to get the gold flakes out.

Also, I am assuming that the settled sodium nitrate is pretty much spent, and cannot be reused to make more nitric acid.

1st batch of distilled sulphuric acid went to my new recovery cell. It works so well I took a week off work to play with it. If I do it right, I can make smoke come off of it. Too cool! (Thanks Lazersteve & GSP for all your help here).


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## lazersteve

Hey Guys, 

Do you get the acid at the local NAPA or do you order from a warehouse? I've got a NAPA store at the end of my block. Do you have a stock number for the 5 gallon size?

I agree with the cleaner is better mentality, but I tend to take shortcuts just like everyone else when I'm in a rush. The drain opener is fine for the cell, but I think the boiled down battery acid will do better for the nitric experiment. 

Unfortnately, I misplaced my 98% conc Sulfuric a few years back along with a gallon of conc HCl and 2 quarts of battery electrolyte that I picked up at the local battery rebuilding shop. I was moving everything out of my old shop into a new bigger one and I think they all got put in a box that ended up in a dumpster.  

I'm think I may devise a new recipie to make my own 'homemade sulfuric acid' . The experiment that readily comes to my mind may be a little too advanced for the forum (handling gases and all) so I'll have to seriously consider if I should post it or not. Who knows maybe I will have another brainstorm and devise a safe way to make sulfuric acid too. :?: :idea: :!: 

Keep up the great posts!

Steve


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## catfish

Hi Steve:

I buy my battery acid from Local NAPA store. It is a stocked item and the Technical info is "Battery Fluid, Acid, UN2796. Casa Number Cas #7664-93-9 and of course the added water. It is 1.25 Specific Gravity and is manufactured by Colonial Chemical Company.Tabernacle, NJ.

It is 65% H2O and 35% H2SO4.

I buy mine in 1.5 US gallons or 5.68 Liters at 4.80 plus tax.

They have it in one quart quanity or you can special order 5.0 gallons. I pefer the 1.5 gallon size, it is not too hard to work with and it is much easier when you have to pour small quanities.

Steve, what I really like about it is that it is pure and no additatives or inhibitors added. It stays very clean and you don't wind up with as much junk in your cell when you are through.

Of course I reduce the water content and get it upwards to 90% plus before I use it.


catfish

We need a spell checker on this machine>


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## PhillipJ

I remember paying $11.oo something for 5 gallons. They had it right at the store both times I got it. And yes, the smaller size is easier to handle. The stuff almost needs to be carted around in 5 gallons. Heavy!


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## lazersteve

Thanks guys I'll pick some up by the end of the week.  

Steve


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## shadybear

I get the 5 gal size at Napa as well. Here in Ohio it cost about $13. out the door. They usually have it in stock unless I want more than 5 gals then it only takes a day to get more if I ask.


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## Anonymous

This thread begin by strong HNO3 and end with strengthening H2SO4. 

I joust want to notify that the protocol to concentrate HNO3 use to be:

Diluted HNO3 to which you add concentrated H2SO4, then distillation in glassware.

The main idea it's that HNO3 is "bond" strongly to water, in fact it's the dissolution energy that we have to provide. At this level, water get out with HNO3, so we have to add H2SO4 to force the water to stay behind. I guess that H2SO4 also compete with HNO3 for solubility.

In all case those distillation are very hazardous I would not try it myself. If there other way... I'll choose it.

For the ion exchange membrane... a bit more about that would be very interesting. 

Where can we buy them? Which kind of electricity can we involve? (12V, 100V, 1KV?)

This can be a very cool solution for treatment prior to extraction, you create an acid bath to dissolve copper and the rest, and remove it from the solution as it dissolve... 

maybe we can start a thread on membranes, I'm very interested since it can also be very ecological (less solution to throw away)


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## postmako

Has anyone heard of this? Sodium sulfate is the salt left over after making Nitric acid from Sulferic acid.

From Wikipedia:
"Lately, sodium sulfate has been found effective in dissolving very finely electroplated micron gold that is found in gold electroplated hardware on electronic products such as pins, and other connectors and switches. It is safer and cheaper than other reagents used for gold recovery, with little concern for adverse reactions or health effects."


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## lazersteve

All,

Here is the link to a NO DISTILLATION nitirc acid. 


Nitric Recipe

It's been fully tested and works. The acid is approximately 50% HNO3 which is suitable for all refining needs.

Steve


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## goldsilverpro

Sodium sulfate doesn't sound right to me. In order to dissolve gold, it would have to form a compound or complex with the chemical. There is no such thing as gold sulfate. It might form a sodium gold sulfate complex but I've never heard of one. The statement may be incomplete. There may be some other chemical involved. Wikipedia gives no details or references. I looked for other internet references but could find none. If such a thing exists, it could be very important.

Maybe they're confusing it with sodium sulfite. This will form a sodium gold sulfite complex but it involves several stages and you have to start with a gold cyanide complex. Not very suitable for gold stripping.


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## jimdoc

Anybody can add or edit a listing on Wikipedia, you 
have to double check alot of stuff.


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## lazersteve

Mako,

The information is you are referencing was already mentioned in this post :

Recycling the by product

GSP,

Here are the google results I found for gold and sodium sulfate:

Sodium Sulfate and gold

A few actually mention sodium sulfate in the process, but typically in addition to other chemicals. Some deal with precipitation from AuCl3 complexes, while others discuss dissolution. Much more research would be required on this subject to have any hopes of coming up with a usable method.

Steve


----------



## postmako

lazersteve said:


> Mako



You can just call me Kory


----------



## goldsilverpro

I went though at least 10 google pages without much luck. The only place it really says that sodium sulfate dissolves gold is in the Wikipedia article on sodium sulfate. Maybe, somehow, the author could be contacted. Chemically, it doesn't seem possible unless a chemical that was capable of forming a compound or a complex with gold was added. This short list includes the halogens (chlorides, iodides, bromides), cyanides, and thiosulfate.


----------



## postmako

goldsilverpro said:


> I went though at least 10 google pages without much luck. The only place it really says that sodium sulfate dissolves gold is in the Wikipedia article on sodium sulfate. Maybe, somehow, the author could be contacted. Chemically, it doesn't seem possible unless a chemical that was capable of forming a compound or a complex with gold was added. This short list includes the halogens (chlorides, iodides, bromides), cyanides, and thiosulfate.



The thiosulfates dissolve gold? Do you know how? I have easy access to lots of Ammonium Thiosulfate.
Thanks,
Kory


----------



## goldsilverpro

I've never used thiosulfate. There are lots of mining methods using thiosulfate. Do a search. We have only touched on it in the forum. With research, it could be a very important method, since it is very safe.


----------



## postmako

http://www.patentstorm.us/patents/6632264.html
*Abstract*
"Processes for recovering gold from copper-gold ores thiosulfate leaching or gold ores copper catalyzed thiosulfate leaching using ion exchange technology are disclosed. The processes include subjecting the gold-bearing and copper-bearing thiosulfate solution to a pH and/or temperature adjustment to reduce tetrathionate concentration in the thiosulfate solution prior to contacting with an ion exchange resin. The ion exchange resin once loaded with gold and optionally copper is eluted with a mixture of sodium tetrathionate, ammonium thiosulfate and sodium sulfite. Gold and optionally copper are recovered from the eluate by electrowinning or precipitation."

I may have to investigate this further...
Cheers,
Kory


----------



## jimdoc

That may be what Action Mining's CLS is. That can be used for
electrowinning gold or PGM's.


----------



## jimdoc

I was thinking of thiourea with the CLS.
Has anyone else tried using CLS from action mining,
or tried leaching with electro-precipitation?
The CLS manual also shows a zinc precipitation unit,
and ion exchange resins that look interesting.
And in his dvd he shows an activated carbon filter
that traps the metals, I was thinking if you would be
able to make something like that from a pool filter?


----------



## chloric1

lazersteve said:


> Here's a very interesting tidbit I just noticed on wiki while reviewing the sodium sulfate salt produced by the above reaction:
> 
> http://en.wikipedia.org/wiki/Sodium_sulfate#Other_applications
> 
> Pay very close attention to the last paragraph of this section (Other Applications). We may have an excellent processing cycle in the works here. One that may even allow us to recycle the by products for reuse. :idea:
> 
> Steve



Steve, 

I am doubtful there is any chemical affinity for gold in sodium sulfate as it is quite inert. Maybe in an electrolytic process but what is formed? I heard THIOSULFATES and SULFITES are use in gold plating baths. You still have to oxidize gold though and halogens and aqua regia are the only means.


----------



## Never_Evil

I know most of you now have your sources of getting the chemicals either through connections or through websites. 

My main question is how do you ask to get sodium nitrate, sulfuric acid, and other chemicals at a local hardware/farm and feed/lawn care store without the employees thinking you are going to make bombs with it?

I tried to ask for the sodium metabisulfite at a local store and explained to them it was used for sanitation purposes. His first call was to a manager and asked if that was a bomb making chemical. Needless to say I tried to get things back on track, but soon left because I had "people" following me. 

thanks

dennis


----------



## lazersteve

Evil,

I order SMB online from thechemistrystore.com

Steve


----------



## Never_Evil

Steve,

Thank you again for giving me a guiding light. I also appologize if I hijacked the thread. My mind is a slight scattered so I thank you all for putting up with my random thoughts and posts. My post wasnt really directed at the SMB in particular, it was just an example and how uncomfortable it made me feel asking for something so specific to a stranger that didnt know my intent.

thanks

dennis


----------



## chloric1

@ Never evil- It usually does not help to explain your intent anyways. Most people expect that whatever you say you are lying. Seattle Pottery supply has sodium nitrate and many other chems fairly cheaply. Pottery chemicals may need purification but that usually is easy.


----------



## scavenger

Swimming pool supply outlets are a good source for cheap chemicals. Sodium bisulfate is usually labeled as Ph reducer and sold in 5kg containers. You can get HCL for a lot cheaper than you can at a hardware store. Ammonium chloride is usually labeled as Pool scrubber or cleaner etc. 
The contents are generally printed on the labels somewhere.


----------



## NobleMetalsRecovery

Just wondering if anyone has given this a try yet?


----------



## Anonymous

Have you tried using calcium nitrate for making nitric acid? I believe that
calcium sulfate is pretty much insoluble.

Jim


----------



## Noxx

james122964 said:


> I believe that
> calcium sulfate is pretty much insoluble.



In fact, thats the real problem...


----------



## Irons

jimdoc said:


> I was thinking of thiourea with the CLS.
> Has anyone else tried using CLS from action mining,
> or tried leaching with electro-precipitation?
> The CLS manual also shows a zinc precipitation unit,
> and ion exchange resins that look interesting.
> And in his dvd he shows an activated carbon filter
> that traps the metals, I was thinking if you would be
> able to make something like that from a pool filter?



Thiourea is very toxic. Don't even think of using it.

http://www.scorecard.org/chemical-profiles/html/thiourea.html

HEALTH EFFECTS

Probable routes of human exposure to thiourea are inhalation, ingestion, and dermal contact.

Non-Cancer: Skin sensitivity in the form of eruptions may occur from repeated contact with thiourea. Thiourea may cause toxic effects on the blood system including bone marrow toxicity and reduction in red blood cells, white blood cells, and platelets. Enlargement of the thyroid (goiter) and spleen has also been reported from exposure to thiourea (HSDB, 1995; Sittig, 1991). The United States Environmental Protection Agency (U.S. EPA) has not established a Reference Concentration (RfC) or an oral Reference Dose (RfD) for thiourea (U.S. EPA, 1995a).

Cancer: There is evidence from studies in experimental animals that thiourea causes liver and thyroid tumors. The U.S. EPA has classified thiourea in Group B2: Probable human carcinogen (U.S. EPA, 1995a). The International Agency for Research on Cancer has classified thiourea in Group 2B: Possibly carcinogenic to humans, based upon sufficient evidence in animals and inadequate data in humans (IARC, 1987a).

The State of California has determined under Proposition 65 that thiourea is a carcinogen (CCR, 1996). The inhalation potency factor that has been used as a basis for regulatory action in California is 2.1 x 10-5 (microgram per cubic meter)-1 (OEHHA, 1994). In other words, the potential excess cancer risk for a person exposed over a lifetime to 1 microgram per cubic meter of thiourea is estimated to be no greater than 21 in 1 million. The oral potency factor that has been used as a basis for regulatory action in California is 7.2 x 10-2 (milligram per kilogram per day)-1 (OEHHA, 1994).


----------



## Anonymous

I must be missing something. If calcium sulfate drops out wouldn't that leave you with nitric solution? That you could just decant off?


----------



## lazersteve

122964 said:


> I must be missing something. If calcium sulfate drops out wouldn't that leave you with nitric solution? That you could just decant off?



What Noxx is referring to is the fact that the calcium sulfate formed literally absorbs all the liquid along with the bulk of the nitric acid (what doesn't get absorbed goes up in smoke). 

If you dissolve the calcium nitrate (as with the cold sodium nitrate method) in a minimal amount of water you end up with a thick pudding of calcium sulfate and nitric acid as soon as you add in the small amount of sulfuric acid. For this reason you would need to distill the resulting pudding to get your nitric out. It works, just not at low temperatures and without distillation like the sodium nitrate method does.

The pudding forms so quickly you will get a plume of nitric acid vapors coming from the reaction as the sulfuric acid is added.

The resulting mush is very toxic and hard to work with. This method is best done in a glass still in a lab environment. 

You could add excessive amounts of water to capture the nitric in the cold, but you end up with weaker nitric, instead of stronger like with the cold sodium nitrate method, and you'll need to filter or distill the calcium sulfate pudding to get all the nitric acid out.

If you are looking for quick, easy, strong, nitric acid just follow my 'in the cold' recipe given here:

No Distillation Nitric Acid

Steve


----------



## Anonymous

I see now, I knew that I was missing something and what you say makes perfect sense. thanks.

Jim


----------



## Palladium

Replay
:wink:


----------



## viacin

I found this, and thought I would see what you guy thought. This seemed like a good place to put it, with all the other nitric processes. Obviously it is played down for people who don't know what they are doing. The only difference is the amount of chemicals this guy uses. According to him you could make a gallon of nitric with 1lb of sodium nitrate, 1.8L of water, and a gal of sulfuric acid. Now that's cheap.

" You can make 2 batches of Aqua Regia or about 1 gallon of nitric acid with one lb of sodium nitrate. Here is the formula for making nitric acid. Pre dissolve 1/2 cup of sodium nitrate in 16 ounces of hot disstilled water and mix this with 1 quart of sulfuric acid. " he doesn't give many more details, but it pretty much follows steves cold process.

Will this work, or will I end up with a solid gel like I read about in another post. And what would the concentration be? I tried doing the math myself, but I still have questions. 

( ? / (?+473) x 100 = percentage

I know that :
? = the mole of nitric acid (63) x the amount of moles in the solution
and 473 is the 16oz's of water in grams.
But how in the world do you figure out how many moles you have in your solution in the first place?

gah...I need a book. Can we include this math in the book Lou has purposed? lol.


----------



## Noxx

Viacin, go see my reply in your last thread.

You would end up with a solid block if you use very little water and cool down your solution. All the salts will crystallize and will form a block.


----------



## butcher

Viacin read this forum over good,also check other info on the computer, it takes time and patients, but all the answers are easily available, and you will be spending more time processing gold. most all questions have been answered on this site, or are easily found searching and reading, of coarse this allways brings up more Questions, to search answers for, also read Hokes book, soon you will be answering your questions before you can think of them, isnt this fun?


----------



## butcher

In my opinion distillation would be only way to make pure nitric at high concentration easily, I have spent many hours studying nitric, can easily be distilled safely, with or without lab ware, if the solution you are distilling from has a high concentration, you will at first distill of just about pure NO2 very little water, the NO2 level in the solution will continue to drop until the boiling solution reaches azeotrope 68%, (can change receivers here), then you will boil off 68% nitric till a salt left. 


But if you are starting with a week nitrate solution you would boil off mostly water and very little NO2 until the boiling solution reached 68% concentration then it will boil off at 68% till dry salt left.

So if you want concentrated Nitric acid without distilling you make it in proper mole ratios such as the formula Steve and others have worked so hard to perfect and studied on, or can use a weaker formula and evaporate off mostly water till 68%, but even freezing to remove salt there will still be a little left, most processes this is not a problem and can be beneficial to some. Usually I see distilling only necessary for purer acid or as part of a refining process that I am using. 
you can check my other post on some simple equiptment I have used safely to distill, also using distilling to process a batch not releasing the Dreaded deadly brown fumes but captureing them for later use.


----------



## viacin

Gah, I double posted. sorry guys. I meant to come back to this one and edit out the question after I posted it in the other topic. Sorry about that, I forgot.

And yes butcher, it does seem that the best (and possibly only) way to make pure nitric acid is to distill. I'm really picky about my chemicals, so I will probably end up distilling in the long run. But the cold method is easy, quick, safe, and cheap from an equiptment point of view, so I really prefer it right now. I was liking this guys formula though because it makes more nitirc with less chemicals. But common sense says that it must be less concentrated then.

When it comes time to make my first batch, which should be this weekend btw, I'm gonna follow Steve's cold method. Later on as I learn more I will try some of the other methods listed here.


----------



## butcher

I would not use distilled nitric if I was starting out, I wouldnt use a nitrate at all, I think you will have more sucsess with HCl peroxide, and Hcl and household bleach methods, unless you are refining high Karat gold ect. the nitrate can be a challenge and hard to drop gold from (wish I had all the gold that was lost from people who disolved it in Aqua Regia and couldnt precipitate it, because of the nitrates) Yes Viacin I can see you will do very well in this field or any other you put your mind to, but you dont need a sledge hammer when a tack hammer will do, and sometimes , well most times good enough is better than perfection,Unless you are in the final stages of pureifying your gold then read up on all of Harolds posts, then you can to get your perfection, but that takes more (time) and expierence, and patients,some wisdom TIME (funny seems to also be associated with age If God gave it to us when we were young we would have waisted it like we did with every else :lol: ) you are a quick study and will soon be sucsessful.


----------



## butcher

I seen where you said poormans nitrates are safe, I dont consider them safe, just relatively safe if handled properly, with all the understanding of the DANGERS involved, before making or using them or any of this information on this forum, or anything i read from a book or got off the intranet ect, I would make sure that I knew the dangers involved to my health, the safety of myself and others, a simple mistake with these chemicals can be deadly, metals and nitrates can form explosive mixtures,nitrates and oils ect very dangerous Do your homework first. not to scare you just friendly reminder


----------



## viacin

Actually I'm going to disolve my extremly impure gold scrap, if it's even gold at all. Call this a test run for a new sample of scrap I have aquired. It's at least 87% base metals, and only about 12% gold. I'm not actually running AR, just a good nitric soak to see what is left. My guess is nothing, but if I'm lucky I'll put in 10g of scrap and get 1g of gold, and other PMG's of course. I decided to go with a nitric soak based on advice from noxx, harold, and husker. Plus hoke states that if you have very impure gold then the nitric bath should be your first step. She even says that it will give me almost pure gold if the scrap is extremly impure to begin with.

From what I understand of this, there will be no precip needed, as nitric alone will not disolve gold(?).

As for saftey, all of my apparel arrived today. I tried it all on and managed to scare the pesky kids in my backyard pretty nicely. I did make one goof up though, I ordered a SM respirator instead of a LG. It still feels like it seals well, but it does not fit on my face where it is supposed it. 

Speaking of which, how noticible is a large quanity of NO2 fumes (assume 10g of gold powder and enough nitric acid to cover them)? My very impure scrap should make a very large quanity of smoke. I live in the country (outside city limits) on a cul-de-sac in a subdivision, and I have a decent sized yard (1/2 acre) with a privacy fence up one side. I don't know all the laws, but I'm pretty sure you shouldn't do this in your back yard, or off of balcony of a apartment in the city. The other side is open to two different neighbors. They are going to suspect something when they see me in my full chemical set up, and I don't think they will think too kindly of what I'm doing. Especially if the wind starts drifting. Maybe I should do it at night, or fire up the smoker grill first.  Any suggestions?


----------



## qst42know

Control your fumes at the source. Just forget my use of the jar, it was a bad idea from the start. I run a marble condenser on all nitric or AR reactions. The less my neighbors pay attension the better.

http://goldrefiningforum.com/phpBB3/viewtopic.php?t=3269&start=0&postdays=0&postorder=asc&highlight=genie

That full chemical gear is going to attract a lot of scrutiny from your neighbors. They're going to wonder if they need the same suits. And they will research the local ordinances for you.


----------



## viacin

qst42know said:


> The less my neighbors pay attention the better.
> 
> That full chemical gear is going to attract a lot of scrutiny from your neighbors. They're going to wonder if they need the same suits. And they will research the local ordinances for you.



My greatest fears exactly. ty for the link.


----------



## qst42know

Two sections of privacy fence hinged together may be enough to deter prying eyes. Hoke recommended a window fan and I use one on days the wind is not cooperating. If the fumes are drawn through the fan consider it dedicated, contaminated, and don't use it for anything else. 

If your neighbors ask what the suit is for do your best to convince them it's your Halloween costume. :wink:


----------



## viacin

ha ha yes, halloween....thats the ticket. I have about 220 feet to fence on one side, and believe me, I'm looking into it. The $3,000 price tag (if I do all the work myself) is prohibitive right now. Maybe after I run a couple of batches


----------



## butcher

I would use acid peroxide to remove the bulk of copper ectera slower and no brown fumes, also cheaper.

with alot of copper takes alot of nitric, creating alot of fumes, even if a plastic trash can over it and you were using fan ect.

your neighbors will probably get that cloud floating through their yard those lil kids you scared may be having a bbq with granny who peaks over the fence seeing you dressed like someone dealing with something somthing the Goverment is looking for.

call the firedept, DEQ,EPA FBI ect.

youll be looking for a black hole to crawl into :!: 

but seriosly try a little batch of HNO3 and copper first so you Know what to expect. and this reaction can get hot enough to break glass , also if you are just starting out and have just a small amount suggest do it in small batches expierimenting the different processes, and not loosing your gold.

Hoke, Harold ect I am sure would eliminate most all the base metals (copper) they could,using the safest and cheapest way first.

then incenerateing to remove chlorides and trash and then useing nitric on the base metals left ( you are not working high karat material, and not in final stages of refining) no need for nitric untill you get to that point and you will be cleaning your gold and re refining it, this is were they are suggesting nitric to eliminate base metals,
( then the nitric can be used and a heck of a smaller brown cloud) and you will have your gold not losing it , :wink: you and your neibors will be happier and healthyer


----------



## butcher

Any black holes in yer cul- de sack :?: 

Can you explain making nitric to the authoritys :!:

just kidding with you here, but do consider my advice I am trying to be helpful


----------



## Palladium

http://goldrefiningforum.com/phpBB3/viewtopic.php?t=315&start=0

8) 8) 8)


----------



## butcher

:lol:


----------



## aflacglobal

8)


----------



## zorba

About the cooling process with the nitric when it needs -5 C, is there any difference if i keep the vessel sealed or opened? 
Will toxic fumes or anything else dangerous be created?

And as i have understood it, is the sodium bisulphate which is the "sludge" useless for any other use?


----------



## lazersteve

Zorba,


Sometime back I posted a process for recycling the bisulphate and/or sulphate produced. It's titled something like 'Nitric Acid Everything but the Squeal'.

I've also since penciled a few other ways to recycle the sulfate by-product.

Steve


----------



## zorba

lazersteve said:


> Zorba,
> 
> 
> Sometime back I posted a process for recycling the bisulphate and/or sulphate produced. It's titled something like 'Nitric Acid Everything but the Squeal'.
> 
> I've also since penciled a few other ways to recycle the sulfate by-product.
> 
> Steve



Alright, i will check that out. 
Still, will it be any difference if i seal my vessel with the nitric when storing it in -5 C ?


----------



## lazersteve

At -5C you'll be fine.

Steve


----------



## zorba

lazersteve said:


> At -5C you'll be fine.
> 
> Steve



Thanks Steve !


----------



## butcher

I do not seal any vessels that go into freezer, or for that matter if they are heated, I keep them open to atmosphere as a heated or cooled liquid needs room to expand or contract with temperature change, I may put a lid on loose.

sealing may not be a problem here but I will not take that risk of a broken vessel with nitric acid.


----------



## zorba

Maybe an awkward question, but when i have boiled off all the H2O from the battery acid, will it differ if 
the coulour of the approximately 98 % H2SO4 is amber or just "ordinary" white ?
At one stage i got the amber colour and at another white, like water.


----------



## lazersteve

The color change is not a problem.

Steve


----------



## IGutYa

ace hardware sells 98% pure Sulfuric Acid in the form of Rooto drain cleaner.


----------



## Dr.Cooper

Here is a transcription of the Prof. Osborn prospector´s book from 1910, and I think today the problem no have great changes.
I hope you find it useful.
Regards.


----------



## lazersteve

Dr. Cooper,

That's the standard method of distilling nitric acid. Unfortunately, most people here don't have access to the required glassware, that's why the cold methods are usually preferred.

I just bought a copy of the same book last week and page 142 in my version does not have the recipe!?! I guess Uncle Sam decided it needed to be removed. Page 144 in my version picks up where the author discusses using potash for sulfide ores, your page 143.

Steve


----------



## docweiser

Tried this twice now.

Ist try I used battery acid where the H2O was boiled off - resulting reaction was weak because of a mistake between C and F.

2nd try I used Easyflow for H2SO4 everything went like it was supposed to except that when I poured off what looked like a colorless and oily liquid into another container it immediately turned into a yellow - bubbly - semi-soild. Cilled further after letting get to room temp - have a solid mass.

Any ideas?




lazersteve said:


> Chris,
> 
> Nothing appears wrong with yours a first glance, except in mine I'm not leaving any Hydrogen behind as follows:
> 
> H2SO4 + 2 NaNO3 --> Na2SO4 + 2HNO3
> 
> The big difference in my recipe is the solubility of the sodium sulfate salt (as opposed to sodium hydrogen sulfate you produce) and the fact that my equation yields twice the nitric acid at a higher temperature ( no dry ice, just salted ice ). :wink:
> 
> I've run the numbers like you did and ended up with about 160 mL of 50% nitric (give or take a few percent) for a single mole of 96% sulfuric and using 100mL H2O to dissolve the nitre.
> 
> I won't bore everyone with the math, but here's my summary (PM me to see all the factors I used to derive this reaction):
> 
> 
> 
> 
> 
> 
> 
> Reaction:
> 
> -Bring 100 mL of Distilled Water in a 500 mL pyrex beaker to 100 C
> -Add the Nitre of your choice (202 gm K / 170 gm Na)
> -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!!!)
> -When vessel reaches room temp (25 °C) put the vessel in the freezer or on a salt water ice bath
> -Let stand until temperature of mixture reaches -5 °C
> -Let stand at -5 °C until all precipitate settles
> -Pour the COLD solution off into glass container with tightly sealed lid DO NOT POUR OFF ANY OF THE SALT IN THE BOTTOM!!!
> -Makes ~160 mL ~50% HNO3
> 
> 
> 
> 
> 
> 
> Steve


----------



## w0lvez

Noxx said:


> Hello,
> Is there a way to concentrate my nitric acid without distillation ?
> I made it with with Sulfuric acid and Potassium Nitrate. Final product is about 30% Nitric.
> Thanks



Why do you want to increase it's concentration? It's very difficult to store concentrated nitric acid because it's very sensitive to light and temperature.


----------



## butcher

Do not boil, evaporate to concentrate nitric acid, you can get it too hot and loose acid, depending on the concentration the boiling point changes, and the highest you can concentrate nitric (evaporate off water) is to about 68%, this is the Azeotrope of nitric acid and water.


----------



## brjook

If this helps anyone.I make my red fuming Nitric with Soodium Nitrate and store bought Sulfuric for drain cleaning.I never used any water in the setup.Just use enough acid to make the Nitrate very moist and start distilling.The nitric starts at about 85c and finishes at about 110c.I have done this numerous times with perfect results everytime.Some say to use ice water to cool your condenser but i found tap water worked great for me .Now this is to make high concentration acid which woul dhave to be dilluted for the purpose of refineing,but concentrated takes up less room and dillute as needed.


----------



## butcher

brjook, there is no reason on this forum for fuming HNO3, many here may know how to make it but we may not share that here on the forum, I personally do not think the forum needs that attention from authorities, or the people that may want a recipe for purposes illegal or that could harm others, information regarding fuming nitric is not needed here on the forum or for refining metals.


----------



## capt_dugout

can amonia nitrate be used as the nitrate


----------



## butcher

Ammonium nitrate can be used to make nitric acid, but I would advise against it, in my opinion sodium nitrate, then potassium nitrate is the better methods.

Ammonium nitrate can have some dangers involved that is the reason, I would advise against its use, also ammonia is a very volatile gas.


spell check editted


----------



## butcher

If you have ammonium nitrate NH4NO3, you can convert it to sodium nitrate NaNO3, using sodium hydroxide,
NH4NO3 + NaOH --> NaNO3 + NH3 (gas) + H2O
The ammonia gas could be used in other reactions or to concentrate an ammonia solution and so forth.

With KOH you can make potassium nitrate, similar as reaction above.

I prefer sodium nitrate for making nitric acid, although potassium works very well also.

there are several problems I see using ammonium nitrate directly to make nitric acid, ammonium nitrate can decompose and possibly very violently, if heated decomposes at 210 deg C, in making nitric if distilled with H2SO4 sulfuric acid and you carefully watched temperature (not >83 deg C), you will get a low yield of nitric acid (lower than with NaNO3 or KNO3), and then as nitric distill off the (NH4)2SO4 will start to decompose giving off ammonia NH3 gas and a salt of NH4HSO4 and decomposing very heavily at 120 deg C. 

now if you are using this for silver you may have some more risk (silver in ammonia dried can have dangers of violent decomposition might blow up in your face), one out here is the nitric would be an acid which may eliminate the chances of this happening) but why risk it leave that for the chemistry major, backyard refiners like me wont play that game.

Here is another formula ammonium nitrate and hydrochloric acid, to give ammonium chloride and nitric acid, both very useful in refining ( the nitric would be distilled off) but her again you would need stiochiometric calculations and then the chances of ammonia in this dilute nitric(??? I am not sure),
NH4NO3 + HCl --> NH4Cl + HNO3:H2O 

As a general rule, keep ammonia away from these metals or salts unless you are really sure what the reactions will make and how to make these potentially dangerous mixture's safe


----------



## kraguj

Is it possible to obtain HNO3 by dissolving of Calcium ammonium nitrate (CAN fertilizer) in H2SO4 (33%), without distilation or freezing? 
Which percentage of HNO3 could be achieved in such a way?


----------



## Noxx

Technically, yes, but the CAN fertiliser has 20%-30% CaCO3 so your nitric will have unwanted salts.


----------



## kraguj

Since this reaction is endothermic I wonder it could be favourable in prevention of losing of NOx??
Also, Ca -salts could be desirable because of theirs insolubility and easy extraction!???


----------



## butcher

calcium salts make hard cakes of sheetrock that stick to your reaction vessels, holding bubbles of your nitric solution inside them, very hard to deal with.

There are reasons why most everybody uses certain chemicals and processes on the forum.
we like the wheels that have evolved from years of others trial and error.....


----------



## Geo

i make my own nitric at home.i condense new battery acid till i get white fuming sulfuric acid and use potassium nitrate i buy on Ebay.its not the most cost effective but it does make tech grade nitric.when distilling i dont add water,i put the nitrate powder into the sulfuric acid,nitrogen dioxide wont be produced untill the sulfuric comes to a boil.well,not enough to see or smell.any water will come out in steam first and acid wont be produced till all the water is gone.thats what is diluting other peoples acid.test the liquid that first comes out with a piece of copper and youll see what i mean.its just water.if you add nitrate to water then add acid all the water has to evaporate first.boiling point of water is 100 degrees C and the boiling point of sulfuric is 327-337 degrees C.


----------



## butcher

Geo, adding some water is beneficial, when making nitric acid from fertilizer salts, even if distilling, but you may have more water in your boiled down sulfuric than you think.


I have the impression you think that not having water that you will make a fuming nitric from the salts, while likely it is of much lower composition than you think, and decomposing HNO3 to NOx gas in solution. I agree you are getting a stronger acid but not fuming, and loosing HNO3 unless you bake the potassium sulfate to the bottom of your reaction vessel and ruining your boiling vessel, there is no reason to make much stronger than 70% HNO3 for refining, and if stronger redistill the 70% with dehydrator.

Fuming is usually made from re-distilling 70% with excess H2SO4 as dehydrator.

If nitric is higher than 68% azeotrope and boiled (or distilled) mostly acid boils off (or over) until you reach azeotrope then 68% boils off (or over) till dry.

If your nitric acid is less than 68% then yes mostly water will boil over first and solution will concentrate to 68% then 68% fumes off till dry.

Without some kind of precision refluxing these will be somewhat mixed, example at first distilling weak nitric wont give you pure water, but mostly water with a slight acid content.

A test to see if it is water is touch a drop to your tongue, acid has some bite sour taste. Or use pH test, for stronger solutions density measurements, or titration.
Even the water will have some acid.


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## Geo

when i first started distilling nitric acid about ten years ago i had no real guide to go by but text books and all i could garner from them was the fundamentals,reagents and a little on the process so it was alot of trial and error.i dont need anything more potent than tech grade.i do understand that nitrogen dioxide will only make nitric acid in H2O so water is essential to the production of nitric acid but it only needs very little like what remains after condensing your sulfuric.my condenser is two pieces of four foot glass tubing that i "engineered" with pvc sleeves as water jackets so when it starts producing acid i never get loose fumes,i collect all thats made.i know im wasting one reagent or the other but i use 1cup potassium nitrate and 1 cup sulfuric acid and get 1 cup nitric acid.not sure about the percentage but it is very strong acid.


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## Platdigger

Kraguj, this posting at the bottom of this page made by James may help:
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=48&t=3345&hilit=Calcium+ammonium+nitrate&start=20
Of course his starting material was calcium nitrate, not ammonium calcium nitrate
but, I am sure there are ways to deal with the ammonia as some have already been
mentioned in this thread.
Not sure about the other salts in the fertilizer grade, and how they would, could be dealt with.


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## zuberb

lazersteve said:


> All,
> 
> I put my thinking cap on at lunch today and fine tuned my original nitric acid recipie from yesterday's post. I'm running the numbers one more time and will be posting a new and improved, never before seen, version of the experiment. The chemicals are readily available, safe, and the reaction produces a product that is more concentrated than the previous version of the experiment. Stay tuned gold diggers!
> 
> Catfish,
> 
> Thank you for the kind words, they make my efforts all that much more rewarding!
> 
> 
> Steve




Steve,

Did you ever complete this? Just curious if you improved on your first recipe, or came to the realization that your new idea wasn't going to work. I didn't see a follow-up to the above statement.

I have a batch from your first recipe in the freezer right now. It's a milky light green color a little lighter green than key lime pie. When I checked it this morning, most of the salts had precipitated, but it looks like I still have a bunch in suspension. I'll check it again after work. I will say, after trying the method on Youtube (sodium-nitrate+HCl+copper outgassing through a tube and pipette through H2O2), your method was much easier to do. Especially since I mistakenly used Muratic when their recipe called for concentrated HCl. I think it was way too dilute, so my small brain thought adding heat would help the process. I ended up pumping too much of the orange gas into the hydrogen peroxide and made a real dirty, real weak nitric.


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## Geo

zuberb said:


> Steve,Did you ever complete this? Just curious if you improved on your first recipe, or came to the realization that your new idea wasn't going to work. I didn't see a follow-up to the above statement.
> I have a batch from your first recipe in the freezer right now. It's a milky light green color a little lighter green than key lime pie. When I checked it this morning, most of the salts had precipitated, but it looks like I still have a bunch in suspension. I'll check it again after work. I will say, after trying the method on Youtube (sodium-nitrate+HCl+copper outgassing through a tube and pipette through H2O2), your method was much easier to do. Especially since I mistakenly used Muratic when their recipe called for concentrated HCl. I think it was way too dilute, so my small brain thought adding heat would help the process. I ended up pumping too much of the orange gas into the hydrogen peroxide and made a real dirty, real weak nitric.



there are different brand names and different grades of muriatic acid, but the typical concentration of hcl in muriatic acid is 32% so it is considered concentrated hcl. check the label on what you used, if it is 32% then its not diluted by much and should work for this purpose with no problem.


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## zuberb

It is the Crown (31.45%, 20 deg BAUME) from Lowes. I found a video about a process to concentrate it up to 35% by placing equal volumes of Muriatic and hydrogen peroxide side by side in separate containers, both inside a larger sealed container. The peroxide absorbs the HCl fumes and becomes 35% reagent grade HCl. The dude says it takes up to two weeks. Does that sound feasible?

The reason I suspected it was too dilute was that I did not get the immediate reaction they did in the video. That's why I added heat. The copper I used was 40g of copper wire I took from transformers in the computers I've recycled. I would say at least 90% of that copper didn't dissolve at all, even under heat. I think I've read somewhere now that I think of it that copper wire is not pure copper. Assuming 31.45% HCL and the sodium nitrate I got from Amazon are sufficient, the wire may have been the problem. Anyway, I like Steve's method better. I think I'll be saving up for a distillation rig though so I can make something stronger than 50% nitric. Sounds like that won't cut it for the silver reactions.


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## Geo

did you incinerate the wire first? wire in transformers is coated with a shellac to insulate the wire from contact with other winding's. even though it looks bare, it is still coated.


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## zuberb

I did not incinerate first. That's probably it because they seemed to react more at the tips. Lesson learned on that one I guess.


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## wywiwyg2000

I used a "How to" site for Nurds. (NERDRAGE) This site provides a way to make three strength's of Nitric acid. Weak to pure. The last of the video will show you how to make the stronger solution.

http://www.wonderhowto.com/how-to-make-nitric-acid-278165/. 

I never made the weak acid, for I did not find the need to yet. If this site is okay to use, I thought the video was produced in a simple format.

Gene


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## zuberb

wywiwyg2000 said:


> I used a "How to" site for Nurds. (NERDRAGE) This site provides a way to make three strength's of Nitric acid. Weak to pure. The last of the video will show you how to make the stronger solution.
> 
> http://www.wonderhowto.com/how-to-make-nitric-acid-278165/.
> 
> I never made the weak acid, for I did not find the need to yet. If this site is okay to use, I thought the video was produced in a simple format.
> 
> Gene



That was the exact video I was talking about. I tried the second method. I don't have a distillation kit to do the third one.


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## zuberb

Ok, first attempt at the cold nitric acid recipe was an epic fail (I think). I came home from work and poured off the clear solution being careful not to pour off any salts. The resulting liquid still looked a little cloudy, so I ran it through two filters in my Buchner. That caught some salts, but the solution is still a little cloudy. The beaker I froze it in contained 92g of salts, and the liquid I poured off and filtered is exactly 250ml. The solution sat undisturbed in a freezer for about 18 hours. Is it possible a bunch of the salts are still suspended? 

I'm guessing that is the case, so I've put the filtered solution back in the freezer to see if it will precipitate more over a second night. I'll filter it again tomorrow. I know the instructions said this should make 160ml of nitric, so I'm not sure where I got an extra 90ml of liquid.

**Edited for accuracy


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## zuberb

Follow up:

No significant precipitate on the bottom of the vessel yesterday, so I took it out of the freezer. I'll test it at room temp on a piece of copper and see if it even acts like nitric.


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## butcher

Because of the ammonium, and its dangers and problems in refining, I feel it woud be best to convert the ammonium nitrate to sodium or potassium nitrate, and then use these to make nitric acid with.


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## zuberb

butcher said:


> Because of the ammonium, and its dangers and problems in refining, I feel it woud be best to convert the ammonium nitrate to sodium or potassium nitrate, and then use these to make nitric acid with.



I used Sodium Nitrate Butcher. Not sure what went wrong.


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## butcher

zuberb,

If you used sodium nitrate 
170g NaNO3 (powder)
100 ml water (liquid)
56 ml of 98% H2SO4 (liquid)

At most you should have close to 159 ml of liquid (nitric acid), and sodium sulfate salts, and these salts would also hold some of that liquid involved in the reaction. 
How did you end up with 250ml liquid?
Where did all of the extra liquid come from? It is probably why you see the cloudy solutions, also if using city water you may have introduced some chlorides from chlorine in the water.


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## zuberb

I'm going to give this another shot when I get the time. I could have swore I measured the water exact, unless my flask is graduated in something other than ml. It's possible I inadvertently used double the water. I use distilled water for all of this stuff because our tap water is loaded with contaminants.

Now that you mention it, there's no way it could have increased in volume unless it pulled 100ml out of the air (not likely).


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## zuberb

I ran another batch, and this time got closer to the right volume of liquid back. It was right at 150ml. I tested it immediately on a tiny piece of copper in a test tube (while still cold). I did not notice a reaction at all other than the fact that the piece of copper wire was immediately coated with a white film. The acid did not seem to attack the copper. This acid isn't supposed to be strong enough to cause passivation right? 

I was assuming there was just too much salt still in solution (although it was clear with a real light green tint). I placed it back in the freezer for another night and it did in-fact precipitate more salts out of the solution. When I tested on copper again, it was more reactive than the first time, but still caused a white film to cover the copper. Is it possible that there is still a significant amount of salt in this acid and that is what is coating the copper? I added just a little heat and it started to react more. This acid appears to be significantly weaker than the nitric I've made simultaneously using the NurdRage method in a separate set of glassware. 

Unfortunately, I only own one amber glass bottle suitable for nitric storage, so I dumped the weaker acid in with my stronger stuff. As soon as I did it, I realized I should have tested both acids separately for approximate concentration. And also that I had probably just contaiminated my good acid with this salty stuff. Piss poor planning on my part.

The next morning, I noticed the tiny amount of acid in that test tube with a piece of copper wire had grown crystals at room temp overnight. Enough crystals to completely occupy the same volume as the acid. I couldn't even see the copper, cause it was buried in these salty looking crystals. Now I realize that the solution still contained more salt. Ughhhh.

Next time I get a chance to try both methods again, I'll try to figure out the concentrations I'm getting from each method. I'm also going to leave the cold solution in the freezer for at least three days before pouring it off. I followed the recipe, but it didn't say how long to leave it in the freezer. I believe I'm either taking it out way too soon, or my freezer isn't quite getting it down to -5.


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## Dravin

hi guys, i was watching all of the different ways in making Nitric Acid. What are your views on 100mls of Hydro peroxide heating it like lazer steves water in coffee pot then dropping the NaNO3 and letting it disolve in the boiling peroxide then adding the 56ml of Sulfurice Acid? Would that make a more potent Nitric Acid?


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## Geo

Peroxymonosulfuric acid is created by reacting peroxide with sulfuric acid. this is a highly unstable compound that when mixed with an organic can explode. of coarse the reagents are concentrated sulfuric and 50% hydrogen peroxide but even the 3% may create a weaker form. some of the chemicals we use work good for what we use them for but when you mix chemicals outside of the guides found here may be trouble. there may be little or no danger involved in what you propose but the reactions i mentioned is a fact and i would err on the side of caution.


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## butcher

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=37&t=1403&view=print


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## Dravin

Geo said:


> Peroxymonosulfuric acid is created by reacting peroxide with sulfuric acid. this is a highly unstable compound that when mixed with an organic can explode. of coarse the reagents are concentrated sulfuric and 50% hydrogen peroxide but even the 3% may create a weaker form. some of the chemicals we use work good for what we use them for but when you mix chemicals outside of the guides found here may be trouble. there may be little or no danger involved in what you propose but the reactions i mentioned is a fact and i would err on the side of caution.




WOW, lol thanks for the reply, i almost did it yesterday but decided not to untill i heard back from the wise.
thanks again 8) :lol:


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## joeybh

lazersteve said:


> Chris,
> 
> Nothing appears wrong with yours a first glance, except in mine I'm not leaving any Hydrogen behind as follows:
> 
> H2SO4 + 2 NaNO3 --> Na2SO4 + 2HNO3
> 
> The big difference in my recipe is the solubility of the sodium sulfate salt (as opposed to sodium hydrogen sulfate you produce) and the fact that my equation yields twice the nitric acid at a higher temperature ( no dry ice, just salted ice ). :wink:
> 
> I've run the numbers like you did and ended up with about 160 mL of 50% nitric (give or take a few percent) for a single mole of 96% sulfuric and using 100mL H2O to dissolve the nitre.
> 
> I won't bore everyone with the math, but here's my summary (PM me to see all the factors I used to derive this reaction):
> 
> 
> 
> 
> 
> 
> 
> Reaction:
> 
> -Bring 100 mL of Distilled Water in a 500 mL pyrex beaker to 100 C
> -Add the Nitre of your choice (202 gm K / 170 gm Na)
> -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!!!)
> -When vessel reaches room temp (25 °C) put the vessel in the freezer or on a salt water ice bath
> -Let stand until temperature of mixture reaches -5 °C
> -Let stand at -5 °C until all precipitate settles
> -Pour the COLD solution off into glass container with tightly sealed lid DO NOT POUR OFF ANY OF THE SALT IN THE BOTTOM!!!
> -Makes ~160 mL ~50% HNO3
> 
> 
> 
> 
> 
> 
> Steve



Couldn't you just add 200gm k/170gm na to 150 ml of battery acid (35% sulfuric 65% water)? That seems like it would give you right around 100 ml water and 52ml 97.5% sulfuric acid which is the end result of all what you said.


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## lazersteve

The point of adding the water as a separate reagent is to guarantee that all of the nitrate is fully dissolved before adding the concentrated sulfuric acid. 

Steve


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## joeybh

That makes sense I'm new to this I was just doing some basic experiments and math and saw that the math was the same.


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## jmdlcar

lazersteve said:


> Chris,
> 
> Nothing appears wrong with yours a first glance, except in mine I'm not leaving any Hydrogen behind as follows:
> 
> H2SO4 + 2 NaNO3 --> Na2SO4 + 2HNO3
> 
> The big difference in my recipe is the solubility of the sodium sulfate salt (as opposed to sodium hydrogen sulfate you produce) and the fact that my equation yields twice the nitric acid at a higher temperature ( no dry ice, just salted ice ). :wink:
> 
> I've run the numbers like you did and ended up with about 160 mL of 50% nitric (give or take a few percent) for a single mole of 96% sulfuric and using 100mL H2O to dissolve the nitre.
> 
> I won't bore everyone with the math, but here's my summary (PM me to see all the factors I used to derive this reaction):
> 
> 
> 
> 
> 
> 
> Reaction:
> 
> -Bring 100 mL of Distilled Water in a 500 mL pyrex beaker to 100 C
> -Add the Nitre of your choice (202 gm K / 170 gm Na)
> -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!!!)
> -When vessel reaches room temp (25 °C) put the vessel in the freezer or on a salt water ice bath
> -Let stand until temperature of mixture reaches -5 °C
> -Let stand at -5 °C until all precipitate settles
> -Pour the COLD solution off into glass container with tightly sealed lid DO NOT POUR OFF ANY OF THE SALT IN THE BOTTOM!!!
> -Makes ~160 mL ~50% HNO3
> 
> 
> 
> 
> 
> 
> Steve



Hi all,

If I would make some of this Nitric Acid I know it is 50% can I use it to process some Sterling Silver? Do I need to add any H2O or use it as is since it not 67% Nitric Acid?

Jack


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## Smack

I would add some distilled water, like 25%.


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## jmdlcar

Hi,

The Sodium Nitre is Na2SO4 and you would use 170 gm Na. I watch the video how to make it and I don't think it talk about 202 gm K or did it and I miss it?

Edit this.
Just found out it is Potassium Nitrate so which is better to use?

Jack


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## butcher

The sodium nitrate is NaNO3 when mixed with sulfuric acid it makes nitric acid, the byproduct is sodium sulfate salts Na2SO4.

In laser Steve's formula above we use 170 grams of sodium nitrate, or if we use potassium nitrate KNO3 we use 202 grams.

For silver it would be best to freeze out as much of the sodium sulfate salts as you can, then distill the nitric acid, which will leave the remaining sodium sulfates behind, giving you a more pure 50% or so nitric acid, without the sulfate salts that would cause problems with your silver. you can dilute this down to about 35% HNO3 with water to dissolve your silver.

If it was a little more dilute I wouldn't worry, as with heat it will still dissolve your silver, and with heating it will concentrate the solution as the silver dissolves.


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## jmdlcar

Thanks for all the help both of you.

Jack


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## amosfolz

Hello all,

I am wondering if anyone could instruct me on how to properly dispose of the leftovers when using LazerSteve's Cold Nitric Method. I have been searching for quiet a while now to no avail.


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## JHS

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=47&t=1300#p10901
try this for waste


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## 9kuuby9

amosfolz said:


> Hello all,
> 
> I am wondering if anyone could instruct me on how to properly dispose of the leftovers when using LazerSteve's Cold Nitric Method. I have been searching for quiet a while now to no avail.



http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?p=40800#p40800


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## joekbit

I have read a bunch of the posts in this section, to date I have not used the recipe. One issue I have seen mentioned is the possibility of a beaker breaking while concentrating H2So4. So being who I am, I had an Idea that I believe can eliminate the danger. Place the beaker in a sand bath while boiling off excess H2o. The sand will distribute the heat evenly and allow for a slower and uniform cool down. It would take more time to heat it up but if safety is a priority it's worth it.

Just a thought, comments more than welcome.

Joe


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## Geo

joekbit said:


> I have read a bunch of the posts in this section, to date I have not used the recipe. One issue I have seen mentioned is the possibility of a beaker breaking while concentrating H2So4. So being who I am, I had an Idea that I believe can eliminate the danger. Place the beaker in a sand bath while boiling off excess H2o. The sand will distribute the heat evenly and allow for a slower and uniform cool down. It would take more time to heat it up but if safety is a priority it's worth it.
> 
> Just a thought, comments more than welcome.
> 
> Joe



The H2SO4 is not the issue. The issue is trying to concentrate nitric acid (HNO3). Nitric acid decomposes from light or heat. Heating causes the acid to evolve several different nitrogen oxides weakening the acid as it concentrates. You can concentrate it quickly which will cause loss of acid or very slowly and retain the acid concentration but its really slow. As a matter of safety, a sand bath or oil bath is always recommended when evaporating with heat.


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## Harold_V

joekbit said:


> Place the beaker in a sand bath while boiling off excess H2o.


One of the buttons that triggers a negative response in me is the mention of "boil" when evaporation is the intended purpose. While it may not be an issue when evaporating sulfuric acid, the use of that term tends to create a bad habit which is then used when one discusses evaporation of values. For that reason, if you hope to remain on good terms with me, do NOT make reference to* evaporation *by using the term ****boil****. I get my shorts in a knot over that issue and become rather aggressive in setting the record straight, as I refuse to stand by and watch careless use of words undo the hard work we've done on this board. It is up to you to learn the acceptable language we use. You'll do that by reading instead of talking. 

Harold


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## joekbit

Harold

Thanks for the notice

Joe


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## necromancer

great post, thanks to Lazersteve, GSP, Palladium, Harold_V, Butcher & Geo (everyone else)
well worth the bump. cold nitric method sounds like the way to go for me.

Lazersteve's Reaction:

-Bring 100 mL of Distilled Water in a 500 mL pyrex beaker to 100 C
-Add the Nitre of your choice (202 gm K / 170 gm Na)
-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!!!)
-When vessel reaches room temp (25 °C) put the vessel in the freezer or on a salt water ice bath
-Let stand until temperature of mixture reaches -5 °C
-Let stand at -5 °C until all precipitate settles
-Pour the COLD solution off into glass container with tightly sealed lid DO NOT POUR OFF ANY OF THE SALT IN THE BOTTOM!!!
-Makes ~160 mL ~50% HNO3


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## 72chevel

Bought a 5 gallon of battery acid today at Napa it was 32.99 and O'Reilly's had the same for 24.99


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## rickbb

72chevel said:


> Bought a 5 gallon of battery acid today at Napa it was 32.99 and O'Reilly's had the same for 24.99



I get a 1 1/2 gallon box at O'Reilly's for $8. Lasts me a long time.


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## Kubik_Rubik

I am going to try the cold nitric method and before I start, I would like to ask a few questions: 
Can the solution be cooled to a temperature lower than -5 ° C, for example -10 ° C, or will it cause problems? And how long does it take to precipitate and settle Na2SO4?
I assume that this not perfectly pure HNO3 is not suitable for dissolving silver due to the reaction: Na2SO4 + AgNO3 = NaNO3 + Ag2SO4? But can it be used to prepare AR and dissolve palladium without problems?
thank you for answer


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## Dragnfly1

I just want to point out some misinformation at the end of this thread. It states that after adding your nitrate salt, you should let the solution cool down below boiling. Well needless to say I tried this and think I may have failed. So I went back to the beginning of the thread to read and noticed that lazersteve states that you should let the nitrate solution cool to room temp before adding the sulfuric acid. Well I just don't want anyone to make the same mistake as me and waste your time and materials by not allowing the nitrate solution to cool down enough before adding the sulfuric acid. Which I think allowed the synthesis to boil when I added the sulfuric acid to the nitrate solution.

Thanks for a great forum, I really appreciate all the information, although it's sometimes a hassle trying to figure out what's right and what's wrong. Lol

have a great day.


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