# Nitric Acid 67.2%



## Eaheisler (Jun 1, 2013)

Can I get away with using 67.2% by just cut with less distilled water for gold filled items?


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## butcher (Jun 1, 2013)

Yes you can use it in all of the processes we use nitric for, diluting it 50/50 with water for silver or base metals, or adding it straight to HCl to dissolve gold with aqua regia, 67% to about 70% (68% azeotropic nitric acid) is what we use in these processes.

When beginning to use nitric there is a learning curve, nitric is a very powerful tool, but this tool needs some understanding and precautions in its use, as with most powerful tool it can be dangerous if not used properly, the deadly fumes, oxidation of organics which can make them more dangerous, boil overs, reactions can get hot enough to break glass ware, and problems with remaining nitric acid as an oxidizer when trying to precipitate gold are just a few of the things you will need to learn about.


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## Eaheisler (Jun 1, 2013)

I've been overly cautious with the nitric. To the point that I'm adding 50ml of water than 25ml of nitric wait 2-4 min before adding the next 25. This stuff scares me.


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## butcher (Jun 1, 2013)

Actually by doing it that way, you are keeping more NO2 gas in solution, which not wasted as gas (Big Red Cloud), with the excess water at the beginning of your reaction, the NO2 gas can reform nitric in solution,added water can also help in keeping reaction a bit cooler, your nitric acid will go a little further to reacting with metals, and the NO2, will stay in solution better to react with metals, and not so much of these NOx gases going up in smoke as the big red cloud of toxic gas.

Diluting with a little hydrogen peroxide in place of some of the water can also help to extend the effectiveness of this hard to get and expensive acid, with added oxygen the NO gas can reform to NO2 gas, with water the NO2 forms HNO3.


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## Eaheisler (Jun 1, 2013)

Great tip in reference to the hydrogen peroxide. Can you give me some %ages to work with?


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## butcher (Jun 1, 2013)

3% H2O2 household hydrogen peroxide is what I use.


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## Eaheisler (Jun 1, 2013)

butcher said:


> 3% H2O2 household hydrogen peroxide is what I use.


I understand that much, do you use that in place of distilled water or a 1/2 & 1/2 mix?


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## butcher (Jun 2, 2013)

You could use it in place of water, as once it gives up its oxygen it basically just leaves water in solution.

I do not use a certain ratio, but I will add it with my water, the oxygen in solution from the hydrogen peroxide Is the component I am interested in, as it combines with any NO gas that forms from the nitric acids reaction with metals and converts it to NO2, the NO2 dissolves in water to reform HNO3.

NO is a clear gas, the NO2 is the red gas we see from the reaction with nitric.

Now this clear NO gas when it leaves solution it can mix with atmospheric air (the air above your beaker) and will join with this oxygen from the air and form NO2 changing the clear gas to the red gas.

So if you have these gases (which can normally be visible as NO2 red gas) leaving your reaction, you do not have enough oxygen in solution to convert NO to NO2 in solution, or enough H2O in solution to absorb NO2 into solution.

With this in mind I tend to go more by what I see, than by a certain measurement, to help me determine how much hydrogen peroxide or water I may need.

Many times I will just add the normal water and a splash of 30% H2O2.

Or I will just add the normal water, a little 3% H2O2 let the initial delayed reaction complete, then begin adding heat externally, warming the solution reacting with metal, and then add a splash of 3% H2O2 every now and then while the metals dissolves (the heat evaporates off water, and drives off oxygen as well as other gases), so with small additions I keep the solution diluted with water and add oxygen to solution as it is being heated.

Excess hydrogen peroxide would do no harm as long as there is enough water in solution either from adding water or from the water involved in the H2O2, the excess oxygen would just gas off, and 3% H2O2 is fairly cheap, so price is not that much of consideration.

If nitric acid is more dilute in the beginning of the reaction, External Heat added towards the end of the reaction can dissolve more metals (this heat which can also be used to concentrate the remaining UN-reacted acid can also help to consume more metals).

I guess I just do not always cook by a certain recipe.


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## Eaheisler (Jun 2, 2013)

Cooking by the same recipe isn't always important as recording the outcome of the product.... This has given me the idea of replacing 10% of my first water wash with the 3% to add in the extra oxygen from jump street. 

Just thinking allowed to someone with much more expierence and knowledge about this... Would it help to keep a spray bottle filled with the cheep stuff in case the reactions begin to get violent. I've noticed by spraying distilled water at the foaming than I can get it under control fairly easily.


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## butcher (Jun 2, 2013)

The spray bottle is a great tool for many uses, and works great for procedures such as you are suggesting now, I only use water in mine.

What I notice when adding a product like H2O2 or others to a solution is that it can react first with the surface of the solution, with hydrogen peroxide we want the oxygen mixed down into the solution, if we sprayed the surface with a spray, the oxygen could react with the surface using up the oxygen and not get mixed into solution, where oxygen would have the most effect.

A fine mist of water can help when you have a cloud of red gas capturing some of it, or the mist of water can help calm a boil-over by knocking down the bubbles, cooling the surface or hottest part of the solution, and diluting the solution mixing water with the gases that are trying to escape all at once.


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## Eaheisler (Jun 2, 2013)

Just an off thought can I use this 67.2 nitric with the hydrochloric aka muratic acid you can get at Lowes to make aqua regal.


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## butcher (Jun 3, 2013)

Eaheisler,
Have you been studying or are you just trying to learn the answer's to millions of questions one at a time, muriatic acid is just another name for HCl or hydrochloric acid, both are just HCl which is a gas dissolved in water to form the acid, nowadays they make what they call green or fume-less acids (or something like that) which can also be HCl with inhibitors included (you do not want this type of acid) just straight HCl or muriatic is fine which can normally be found at hardware stores or building supply's, or where they sell brick and supply's for brick, block or concrete work, pool and spa supply houses can also have it (as well as many of the chemical's we use).

32% HCl and your nitric would make aqua regia.

But if you have to keep asking these simple questions, then it is obvious you would not be ready to have these acids, much less mix them together or with metals, there is a lot of safety and understanding you would need first, spend some time in the safety section, and reading through the forum, really this is the way you will learn, asking questions one at a time it would take you a million years of getting answers before you would even be ready to begin, by studying and reading through the forum, millions of questions you have not even thought of yet have been answered, by reading you get ahead faster, learning answers to millions of things before you even know what to ask, and learning so many things you would never even think to ask.


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## SilverPirate (Jun 11, 2013)

butcher said:


> Eaheisler,
> Have you been studying or are you just trying to learn the answer's to millions of questions one at a time, muriatic acid is just another name for HCl or hydrochloric acid, both are just HCl which is a gas dissolved in water to form the acid, nowadays they make what they call green or fume-less acids (or something like that) which can also be HCl with inhibitors included (you do not want this type of acid) just straight HCl or muriatic is fine which can normally be found at hardware stores or building supply's, or where they sell brick and supply's for brick, block or concrete work, pool and spa supply houses can also have it (as well as many of the chemical's we use).
> 
> 32% HCl and your nitric would make aqua regia.
> ...



True story, if you read this forum there is no need to ask questions...
This is my first post by the way.


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## butcher (Jun 12, 2013)

SilverPirate,
Congratulations on your first post which adds good content to our forum, welcome to the forum, I expect once your ready we will learn a few tricks from you too.

Nice avatar of fine quality gold did you refine those buttons?


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## SilverPirate (Jun 12, 2013)

I sure did, and would like to thank you and many others on the forum for making that possible.


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## butcher (Jun 12, 2013)

SilverPirate,

The quality of your gold you refined, is impressive especially for someone who did not ask questions to learn. You sir are proof that study produces results, to be able to refine gold of that quality, without spamming the board with questions, proves your ability and skill, you are also just the kind of member that make this forum such a great place, I am looking forward to learning from you, this is a very wide field, and I know you will be learning and studying things that I have not had a chance to yet, I also will be glad to help you with what little I have learned.

Very nice Job on the gold, it does make a nice avatar.


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## Eaheisler (Jun 19, 2013)

Butcher,

I read a ton and have a notebook full of information I've gathered from the more experienced on this sight (TBIs make it difficult to remember lots of things). From what I've read prior here has been made directly referencing 70% or, not specified so I've assumed they were speaking about 70%. The search brings up a lot of posts about how to make and, where to find suppliers but, I didn't see any directly referencing 67.2% so, I asked.

I tell all my soldiers no question is a dumb question but, every mistake is preventable.


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## butcher (Jun 19, 2013)

Eaheisler, 
You are very correct their are no dumb questions, but before we go to battle we need to train and learn a few things, in the heat of a battle, it is not a good time or place to ask questions, but with studying and training, you will have very little need to ask questions during the battle, you will have an understanding and know most you will need to know to win the battle.

I also understand when you are a new troop their are so many things to learn at once, and at times you may need help finding the answers to your questions, but as you train more, it actually gets easier to learn and find those answers your looking for, it is like a soldier, as he trains his muscles get stronger, and he can do much more the harder he works, the stronger he gets and he will be able to do what he could not when he first started training.

We do not mind answering some questions if you are doing your home work, and there are not any dumb questions, but I can guarantee you this, you will learn much more from studying than you can by asking a few questions, when you ask a question you get an answer to that specific question, when you study you get thousands of answer to your question, and a thousand other questions you would not even think of to ask, when you ask a question the answer to your question will be limited in details, or limited on the possibility's available, when you study the details are almost limitless, and the possibility's are open to you.

May I suggest when you make that note book that you make the pages replaceable, and where you can add pages or take pages away, or rewrite the pages as needed, I have a notebook that I started years ago, in my note book the pages were not replaceable, as I learned more my old notes needed rewriting, I needed to add notes to the full pages, I could not rearrange pages, so now I have a large notebook full of notes, some good some bad notes, my note book will need rewritten, it took me years to write this one. it will take me years to rewrite it. as you learn more many of the old notes are useless as you learn better ways of doing things, also as you learn more, you do not need many of those notes, you know it, but many things are very helpful in your notebook, things you may forget easy or cannot memorize like the reactivity series...

I do not have any soldiers but if I did I would tell them to study and prepare themselves, then ask questions as needed.


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