Chemical deleted

[zzz]

I have problem with language, because english in not my first, but i think is explained fair enough.

 

[butcher]

ZZZ,
You have done very good considering this forum is not in your language, I do not think I would do as well trying to explain myself in another language as you have done here.

Lets begin again new with our discussion and try to help each other:

Lets look at what we would have if we tried to recover our aqua regia through distilling, while we were dissolving some gold.

When we mix aqua regia the two acids react and form volatile gases in solutions, these gases also help us to dissolve gold as they react, they will not stay in the solution long, and will leave the solution in time, they can also be driven off with heat or from the heat of the reaction (faster than they would if the conditions were different), this is why it is not recommended to make your Aqua regia before you need to use it, on standing these volatile gases would leave the solution, if you stored it for a while, these gases could also build pressure in a closed vessel breaking the vessel if the gasses had no escape, once these gases leave the solution it is no longer aqua regia, yes it will still be a very strong acid, but it will not be able to dissolve much gold without these volatile gases reacting with the gold.

When we distill the aqua regia solution as it reacts with the gold, we do get these volatile gases coming over in our distillation with the first water that is distilling off (these gases are still volatile some may react with the water and reform some acid, and much of it would just vapor of even if we tried to capture them)
So what would our product be from capturing the aqua regia with distillation evaporating the solution and condensing it back to an acidic solution free of metals left behind in our boiling flask of gold metal, the condensed acid would still be very strong, but it would no longer be Aqua regia (just as storing aqua regia the volatile gases either reacted and left our solution, but we would still have a very acidic solution containing ions of hydrogen, chlorides, and nitrates, in our receiving vessel.
What were these volatile gases we are talking about nitrosyl chloride and chlorine, as well as other gases in the reaction with gold like nitric oxides.

Can we reuse this very strong acid we captured to dissolve other metals? Yes we can.
Can we use this in other chemical reactions to make salts of other metals? Yes we can.

Why do I say we cannot use this to dissolve silver? The solution would contain Chlorides.

But what about the fact that the gases evaporate off of our solution at different times during the process with water first, then nitric, then HCl, why can't we separate these and condense them separately, this way we could distill back nitric from our aqua regia, well first these gases will not evaporate off as pure substances, and they will also be mixed with these other volatile gases we discussed above reacting in the solution or with the gold.

So this is why I replied to this statement:
Recovery the nitrate salt for make distillation: obviusly the nitric used to make aqua regia is irrecoverable, but if you used that for dissolve silver for inquartation
By saying:
(Silver will passivate in the chloride solution)

You can use this strong acid you distilled off, for many things, but using it to try to dissolve silver would be a bad idea, because of the chlorides involved and the problem of silver passivation of silver chlorides.

 

[zzz]

You have tried to spot errors where there are none, now you are off topic.

 

[butcher]

ZZZ,
Sorry you feel that way, I will no longer attempt to discuss this subject with you, you apparently want to see this your way, and do not wish to see where your thoughts on how the chemistry may work differently than you think it does.

Or you seem to feel what I say about what I see wrong (or what I understand of the chemistry) that we discuss has something to do with you or what you have written, or you personally,.
ZZZ, that is not my reason for looking for or spotting errors.


Personally I want to learn how things work even if it does not work the way I think it does, this way I can adjust my thinking on the subject and see how things really do work.

Chemistry is very complex, to learn it we need to be able to see things differently, or see when things are not the way we think they are.

Yes I do try to spot errors, I guess that is how I work, when I know the error, I can then fix the problem, or understand the chemistry better.

You seem to feel I am spotting errors has something to do with you personally:
That is not the case here.

 

[Dr_Code]

I found this thread by searching for butcher's thread about 'killing two birds with one stone', related to processing pins from PCI slots and the like. I will get to reading my intended thread soon. This method reminds me of a video I saw on how to make nitric acid using a condenser.

Being a new thread, I wanted to add something about the saftey aspect of pure, or 'fuming' Nitric Acid - It is DANGEROUS STUFF.

Pure Nitric Acid will form a protective coating arround copper (called passivation) (I'm not sure about what other metals this happens with...I've seen it done with copper), making it dissolve very slowly, untill the acid is diluted a little. Then the reaction is VERY violent!

Yet another reason to add acid to water. AAA. Always Add Acid. (At least that is how I remember it)

 

[Dr_Code]

Perhaps the inital process was misunderstood. There are many ways to make Nitric Acid. Taking three ways to make Nitric Acid, and turning them in to one way. Two processes use Cu (copper) (which I did not see in the inital example). If used, the Cu could be recovered using Al (Aluminum). (I also did not see Al in the first reaction. I did see CuSO4...which made me think of this method).

It may have all been a mixup from a Nurdrage video (MOD's, please edit this if necessary).

 

[cableman]

I realize that I am adding to an older post but I am researching ways to make my own nitric acid. Right now I really need the simplest method to begin with but I read your distillation method closely where your use your gold plated copper pins to recover the gold off of the pins while using the underlying copper to help make your reaction all the while producing the nitric acid I need. I am very interested in this method but I am not experienced in distillation processes. I have most of the equipment I need except for a few inexpensive pieces and I would love to see a detailed picture of your setup if you could take one the next time you have it properly set up for the process you explain using the gold plated copper pins and distilling using sulphuric acid. I only need to find an inexpensive place for the copperas you use since all I have used so far is SMB.

If you ever see my addition to this post and have the time I would greatly appreciate any pictures you might have of your setup. I would also like to know the simplest method to make the strongest nitric acid I can preferably using sodium nitrate. I don't mind using a little extra materials so long as they are not expensive. My only goal is to get some usable nitric acid to precipitate and refine several grams to an ounce of gold so I can use this funding to purchase the rest of my preferred equipment and chemicals. I only need to make a pint (give or take an ounce or so) of nitric to achieve my goals.

 

[butcher]

cableman,

Sorry for not answering sooner, had trouble with my internet connection, the company that services my area was having antenna troubles, (some competitor company put up an 2.4giga hertz antenna on the tower right below his antenna and drowned out his signal, well I contacted them this morning as I was wanting to be able to use the internet, and asking why it has taken them 3 weeks to get this thing working right, he said he has the antennas ordered from Europe he said his tower man was hurt, and could not do it now, so I volunteered to climb his tower to replace the antennas for him, 7 hours in the cold, 3 hour trip up and down eight dollar mountain well now I got my internet working again, and the owner Rob said he would pay me for the tower-work with free internet connection.

If you have a lab glass distilling rig you can use it, the glass is better than the gallon pickle jar, but as I explained in the post killing two birds with one stone, precautions are need to be taken to keep from breaking glass, read the thread paying attention to how to treat your glass so as not to thermal shock the glass, or create hot spots, and on preventing suck backs, of cold liquids into the hot boiling vessel, do some study on distilling before using your glass ware distilling rig.

A lab beaker and home made Teflon lid would work also, I have a coffee pot shaped like a flask I made a Teflon cork for with a hole drilled in it that is also used to distill with. I have bought a lab glass distilling rig and never used it as my homemade stuff works just fine, I have started buying some pieces of lab glass, and working towards getting a larger distilling rig setup a piece at a time, I got a nice condenser that should work better than a plastic hose coiled in a bucket of iced water, I still need some joints and other parts before I will have it working though.

If I get a chance I will take a picture, nothing impressive, I explained what it was, the only important part is the lid for the pickle jar is made out of Teflon turned on a lath, to fit the jar tight and with a lip to seal at jar top lip with a hole for the hose for the gases to pass out of the gallon pickle jar which is sitting in the pot (sand bath) to evenly heat the pickle jar.

If you just want to make nitric acid the best way is to use Laser Steve's recipe for cold poor mans nitric acid, freeze out the sulfate salts as much as possible, this makes about 50% HNO3, His recipe make about 150ml:

100ml distilled boiling water
170g NaNO3 (or 202g KNO3) dissolve
Cool below boiling
Very slowly add 56ml of 98% sulfuric acid, reaction creates heat and can boil over from reaction if acid added too fast.
We want the salts to dissolve and convert, stir solution well,
Cool solution down slowly to room temperature (potassium sulfate crystals can lock up some HNO3 if cooled too fast
Chill solution in freezer, or in salt ice bath (do not seal vessel to allow for expansion and contraction, Steve recommends -5 deg C.
Decant HNO3 liquid from sulfate salts while solution is cold.
Makes ~150ml of ~ 50% HNO3
To get 68% azeotropic nitric acid evaporate water, heat till water vapors escape, but do not bring to a boil 50% HNO3 has a boiling point of 114 deg C so we want to keep temperature below this, as acid concentrates the boiling point rises a little, but water will vapor off below the boiling point of the acid at that concentration of the acid, 68% HNO3 has a boiling point of 120.5 degrees C, after the acid reaches azeotrope the boiling point of the acid begins to lower, we cannot concentrate the acid past the azeotrope as further heating would just vapor off 68% acid, (68% nitric acid the strongest you can make it with this method), I know how to make nitric stronger but there is no reason for it in recovery or refining, So there is no need to post a process that someone could use for the wrong reasons such as making explosives.

You can use the recipe above, for larger batches
Times X 6 formula to fit in a Mr. coffee pot sitting in a casserole dish on a solid burner hot plate with a watch glass lid to make about a quart of HNO3:
600ml of distilled boiling water
1020g NaNO3
Or
1212g KNO3
Cool solution
15ml 30% H2O2 (helps to keep NOx fumes down and convert them to acid)
Slowly add
336ml of 98% H2SO4 (add it very slowly, taking pre-caution of boil overs).
Stir well when salts dissolve cool down pour into two Quart canning jars, with loose fitting plastic lids
Cool to room temp, freeze to form sulfate salts, decant while still cold,
This will make about a quart of 50% HNO3, evaporate off water to 68% HNO3 (you can use the specific gravity test for percentage if you are concerned about how strong it is)
The HNO3 can just be distilled for higher purity to use on silver.
The 50% nitric will need diluted for use on base metal or silver so no reason to concentrate if wish not to, also the 50% nitric acid can be used in aqua regia just fine where you are heating solutions any way which will concentrate the acid then (this also helps to lower NOx fumes during the process)…

Store HNO3 in dark glass, light destroys HNO3; lids should be able to handle acid.

You can then distill the homemade 68% nitric acid to distill a clean nitric acid (leaving the remainder of the sodium or potassium sulfate salt behind in your boiling vessel, giving you a more pure nitric acid that can be used on silver.
(Sulfate salts left in home made nitric will form unwanted silver sulfate with silver)

Killing two birds with one rock is also a nice process if you have pins to remove the gold from, and want to make nitric acid and copper sulfate in one reaction, it is actually a little harder to master, than just distilling HNO3 but once you do it properly you will love the process.

Ferrous sulfate (copperas) also called Iron II sulfate, is also easy to make, I have made several posts on how to make it using cleaned Iron from scrap transformer laminates and 10% H2SO4, heated, (sodium bisulfate NaHSO4 can be substituted for sulfuric acid in the reaction), the bisulfate will act like sulfuric in many chemical reactions.

 

[JesseSShaw]

After reading this thread for awhile, I figured I would share information on how I produce nitric acid for my PM recovery. Thanks to our government (tongue in cheek) it is very expensive for me to acquire nitric acid. I can not find it anywhere near close enough to my location and it is ridiculously expensive to order it and have it shipped. Yet I can buy sulfuric acid comparatively cheap online, go figure. I make semi-small amounts of nitric acid so I do not need to store much for when I need it. My batches are concentrated above 86%. As you may or may not know, nitric acid is considered highly concentrated when it fumes and it starts to fume at 86% concentration. My homemade nitric acid is contaminated with nitrogen dioxide but the contamination seems to be non-reactive when I am using it for PM recovery.

I use sulfuric acid and sodium nitrate in a basic distillation apparatus to produce my nitric acid. Sodium nitrate is more readily available to me than other pure nitrate salts but you should be able to use any pure nitrate such as potassium nitrate, calcium nitrate, or ammonium nitrate. It is a simple process but can be dangerous if the proper safety precautions are not met so make sure you do this outside or under a proper fume hood. You don't want to experience nitric dioxide or nitric monoxide poisoning. First you must have a distillation apparatus that will handle the extremely corrosive substances involved in the process. I used a distillation apparatus with rubber stoppers for the first few times and the rubber reacted by breaking down. It didn't seem to effect the reaction but still, not easy to clean up afterwards. Best to use an all-glass setup if possible to avoid unwanted reactions. I combine 100g sodium nitrate with about 60ml to 70ml of sulfuric acid. Then I distill the solution until there is no more distillate to collect. The collected distillate will be nearly pure nitric acid. It will have a somewhat yellow tint because of the decomposition of nitric dioxide contamination but it isn't much. You will still have very pure nitric acid (I would say somewhere between 90% to 95% pure). The stoichiometric quantities for this reaction do not seem to work as expected, unless my calculations are just incorrect. I played with the amounts and found the quantities that I mentioned to work best.

I took a lot of information for granted in this post. Don't use this procedure unless you have at least a basic idea of what the process involves. DO NOT underestimate the dangers of nitric acid especially in a pure state. I just wanted to share information on what I do for acquiring the ridiculously expensive nitric acid.

 

[lazersteve]

Jesse,

Your rig looks like it would make a lot of NOx vapors in the area where the reaction is run. The reason I say this is because your collection flask and condenser do not have a good seal with one another. When I distill nitric acid using the chemicals you suggest, I get a clear to yellow liquid, with red vapors in the condenser, especially near the end point of the reaction. I use a laboratory grade rig with blown glass Pyrex and ground glass joints to prevent this gas from escaping. I use a one liter flask for my reaction vessel and a 500 mL collection flask. If my joints on the rig are not tight (I use Teflon tape to seal them), I get red vapors emitting from the collection end of the rig towards the end of the reaction.

How do you contain the red vapors exiting the condenser? I would recommend that anyone who wants to distill their own nitric acid to use a closed connection to the collection flask with a salt water and ice cube bath on the outside of the collection flask. I use a vacuum flask for my collection vessel. Additionally, if you run the reaction under a vacuum, your acid will distill over at a lower temperature. By cooling the collection flask, you ensure the acid vapors are properly condensed and collected in the collection flask.

I'll see if I can dig up some photos of my rig in action. Distilling nitric acid is fine for lab scale quantities as long as you do it safely. For larger scale work, purchasing nitric acid is the best way to go.

Your numbers may be off on you calculations due to the concentration of your sulfuric acid and/or your nitrate purity/water content.

Steve

 

[JesseSShaw]

Your rig looks like it would make a lot of NOx vapors in the area where the reaction is run. The reason I say this is because your collection flask and condenser do not have a good seal with one another. When I distill nitric acid using the chemicals you suggest, I get a clear to yellow liquid, with red vapors in the condenser, especially near the end point of the reaction.

That's right. Nitrogen oxides are an unavoidable byproduct of the process. That is why I indicated that the process must be done either outside or under a proper fume hood (or good forced air ventilation of some kind). I will add that if you are doing it outside then make sure to stay upwind lol.

I use a laboratory grade rig with blown glass Pyrex and ground glass joints to prevent this gas from escaping. I use a one liter flask for my reaction vessel and a 500 mL collection flask. If my joints on the rig are not tight (I use Teflon tape to seal them), I get red vapors emitting from the collection end of the rig towards the end of the reaction.

It is best to use an all glass setup as I indicated. The reason is for preventing unwanted reactions. Also, I prefer to use lab quality or cooking quality borosilicate glassware which has very low thermal expansion so there is less chance of the glass breaking due to thermal shock.

How do you contain the red vapors exiting the condenser? I would recommend that anyone who wants to distill their own nitric acid to use a closed connection to the collection flask with a salt water and ice cube bath on the outside of the collection flask. I use a vacuum flask for my collection vessel. Additionally, if you run the reaction under a vacuum, your acid will distill over at a lower temperature. By cooling the collection flask, you ensure the acid vapors are properly condensed and collected in the collection flask.

That is certainly one way to go. Turn the collector into a second condenser. However, I am not worried about the oxide gases escaping. Actually, I prefer not to further contaminate the distillate with the decomposing nitrogen oxides. However, I understand that there may be a process to further purify the nitric acid by exposing the end product to a bubbling vacuum of some kind but I have not looked into it. Your vacuum collection vessel may indeed provide that additional purification step. The HNO3 that escapes as vapor is very little so I am not inclined to complicate the distillation setup. Maybe I will try an enclosed collection system sometime and see what I get but the process I outlined works extremely satisfactory for me.

Your numbers may be off on you calculations due to the concentration of your sulfuric acid and/or your nitrate purity/water content.

Steve

I considered that but It doesn't seem like it would throw off the calculations that much with the sulfuric acid being 98% concentration and the sodium nitrate being 99.2+% concentration. I will have to go over my calculations a few more times and see if I can spot errors that I might have made, which is very possible.

I want to add that I am not a chemist. I am in fact a computer and electronics technician and have been one for about 30 years. That is where my true vocation is but I also have a love for the sciences in general. I just make the effort to learn all I can about whatever it is I feel I need/want to learn for any given circumstance or situation I find myself in. I try to make sure I have a comprehension of whatever it is that I am working on. Since science is everything and everything is science then that encompasses just about everything.

 

[au-artifax]

The reason a lot of readers are having a hard time understanding is that there are so many mistakes and errors. For example, will someone please tell me how, if you use ammonium nitrate fertilizer and sulfuric acid you end up with sodium sulfate?
And so many places some writings are totally oblivious to the laws concerning conservation of matter and energy. Ex:so we take all this wonderful NOX and just pump it through water, or condense it, and "pooof", it's HNO3 again. First, if we are talking about the waste gasses from AR, they are of a nitrosyl chloride complex. If we are just talking about dissolving silver, copper, and base metals then we are loosing most of the nitrogen molecules making silver or copper nitrate. So we are supposed to forget that the hydrogen ever existed? The NOx gasses coming from the reaction with HNO3 making salts with metals is the decomposition of the nitric acid and NOT all the waste is NO2.... Some just NO.... Some free H.... Some fre
You're not gonna have your cake and eat it too when using nitric because you never know what state of decomposition it is in. Ultimately it will be just break down to its elemental state...with some water too.

I will be posting in the future how I make my 1.51 WFNA without a retort, without a vacuum, without water, without electric arcs, just three chemicals and three stores. Cost runs between $30-45/lt after making the rig.

 

[butcher]

au-artifax,
I know how and can make nitric acid that strong, I am not sure what method your talking about right now but I believe it is besides the point, there is no reason for nitric acid stronger than 70% in recovery and refining, nitric of higher concentration has no place in refining, and we really discourage instruction for the fuming nitric, there are places where anyone making it can learn without being here on the forum, nitric of this concentrations is usually made to make other things that we also do not wish to have discussed here on the forum, this forum and its members are already flagged as characters for the governments to watch, we do not need more prying eyes, also not only dangerous and useless in recovery or refining, teaching others here how to make fuming nitric could get people hurt.

Lower the concentration of your nitric to around 70% and make your tutorial of that concentration, we will all then be very interested in reading your methods.

 

[au-artifax]

Thank you for your help. You are right. I should be discussing something more to the point. Given that, I usually start from the 1.51 with no free NOx and then dilute it. It is actually easier for me with less steps to do it that way, and I do end up with 70% at my second to last stage/vessel, and altogether the reaction shows no leftover fumes in mylast vessel which de-acidifies anything that sneaks past. I guess you could say my method involves counteracting/not allowing decomposition to occur. There is a designed failsafe in my rig, and a fee must do's, so the chance IS someone would take a short cut and get hurt.

Seeing as the initial thread had to do with "efficiency", I thought this was the right place. I do agree with you though, and will skim around the complete picture of the rig.

Anyways, the question I have is how do you do an accurate dilution of full strength HNO3 to 68-70%? Is it just a simple ratio of volume, or weights? I don't know for sure.

 

[butcher]

Nitric acid Has an azeotrope of 68% to 70%, nitric acid if made with some water involved in the acid or reaction will make nitric acid of a strength of the acid/water involved, so if you were making nitric with sulfuric acid, diluting your sulfuric acid to about 70% will make close to 70% HNO3 (for safety we always add water to concentrated sulfuric acid),depending on which nitrate source you use, sodium or potassium can also have an effect on how much water you would wish to add, when distilling it is best to have a little more acid and water, so at the end of distilling you are not cooking salts in your distilling rig.

Extra water is no problem, because we can distill a weaker nitric acid, and then concentrate it up to its azetrope 68% by simple evaporation.

It is possible to make nitric acid with ammonium nitrate, but this can be dangerous and so we try not to discuss it here on the forum, ammonium nitrate can be too dangerous if the reaction is not run properly.

It is also possible to make nitric acid out of other metal salts besides sodium nitrate or potassium nitrate, we can also use copper nitrate salts or other metals salts.

It is also possible to make nitric acid in a reaction while you are dissolving the copper from gold plated pins, to recover the gold foils, distilling off the gases to make a useable and clean nitric acid leaving you with gold foils in a solution of copper sulfate (the copper sulfate can be used in electrolysis or for other uses in the lab, I have posted a method I use to do this called killing two with one rock.

making nitric acid is fairly easy, distilling nitric acid is easy, a good product can be made that will serve well in recovery and refining, dilute nitric about 35% HNO3, can be made and used to dissolve base metals and can then be distilled to dissolve and recover a purer silver, or the nitric acid can be made 68 % and distilled at its azeotrope, and then diluted for silver or use on base metal, the 68% can be used with aqua regia, also you can make aqua regia with a more dilute nitric acid and use heat in the reaction while dissolving metals, many times this can actually be benificial in many reactions like with the PGM's or with gold that has more silver than is desired, it can also help on fumes and help to make the acids go a bit further.

Distilling is easy but it has to be done properly, before trying it a person need to study how it is done and study the safety precautions, they need to understand simple principles, like a pressure vessel builds pressure on a boiling flask but when the heat is removed and solution cools it can create a vacuum, this vacuum can suck back cold liquids into the hot boiling reaction flask, then this cold liquids hitting the hot acids and hot glass can shatter the boiling vessel splashing hot acids all over you or your lab, an understanding and simple precautions can prevent this, and of course simple common knowledge in the lab to prevent thermal shock on glass ware, or fume control and its dangers and other safety concerns...

Here is a link to killing two birds with one rock, in this I use a pickle jar as a distilling rig, a lab-glass distilling rig would be better and can be used, but it is not totally necessary if precautions are followed, I also discuss some of the safety aspects when distilling or using a distilling rig.

http://www.google.com/search?hl=en&as_q=kill+two+birds+one+stone+&num=1000&ft=i&as_sitesearch=goldrefiningforum.com&as_qdr=all&as_occt=any

I have also made many posts on making nitric acid, and have given information in posts on nitric acids properties including boiling points, density, specific gravity, and azeotrope, and formulas, Nitric acid is one topic that I have studied in great depth to learn everything I could find out about it, so I do have considerable knowledge in its subject.

The density of nitric acid is a measure of weight (compared to water).
The content or percentage of nitric acid in water ( or fumes) is also by weight.
Nitric acid has specific boiling points, for a specific density or concentration.
Density or percentage of nitric can be measured with specific gravity or by titration, but can also be determined by its boiling point.

 

[au-artifax]

There is a little known realm of science that deals with multiple atmospheres. Example, atmospheric pressure has a given effect on fluids (including gases), but not every substance is affected the same. Water is affected to a different degree than say nitric acid. So what if two substances vapor pressures can changed? One might have its boiling point rise ten degrees at two atmospheres, while another might see it's boiling point increase fifty degrees at the same two atmospheres.

This is where the noise starts.... I study pressures..... And I do my procedures using multiple amospheres, including distillation. I push the product through, not suck it trough, and I can control vapor pressures and purity better.
Now you can start talking about safety, but it's easy to make fail-safes part of an apparatus.

 

[au-artifax]

I forgot to mention, pressure affects crystal formation too. Everything has a crystalline structure. Certain precipitated can form... Or not form.... Given a specific pressure. Think about it....that diamond your significant other wears is really just a limp of coal.

 

[butcher]

As a boiler-man I am well aware of the effects of pressure or vacuum and boiling points of water, but I have not done as much study concerning many of the different fluids or acids, although I have done some study on the subject of using vacuum or pressure to distill nitric acid and other ideal and non ideal liquids, Raoults laws,and fractional distillation of liquids,and phase diagrams, and so on, enough to understand the principles, I also understand much of the safety concerns with working with liquids at high pressures and vacuums.

I am always willing to learn more.

 

[solar_plasma]

@Butcher

Thank you for your great tutorials, your patience and the time you spend for writing those!

 

[butcher]

Solar,
I just do the same as you and others share what I learn, I just share what I learn form the rest of you great forum members.