Refining of fingers from a single card

[Anonymous]

I would think having digested the foils in acid, an AA analysis would give gold concentration which could be applied to the dilution factor. This will eliminate any losses due to melting and gathering all of the gold into a single bead, which in these micro quantities is difficult at best. This is how it is done professionally to obtain useful data on value per specific piece. This data is catalogued and only spoken about in select inner circles within any refining company. However knowing the actual recovered value of a specific circuit is valuable information.

Darn. I was going to type that 4metals. I didn't completely understand the method that Bjorn was talking about so I wasn't totally sure if I was correct, therefore I passed up the opportunity. Glad to know my hunch was correct though!

Jon

 

[g_axelsson]

What you are saying is that it was wrong to scrap these machines?


Göran

 

[Grelko]

Only if it's fuming red or white. The 68 - 70% we usually use will not cause your hands to burst into flames.

Dave

Could someone go into more detail about this please? Unless you are talking about highly concentrated "fuming" Nitric giving off white fumes, or instead, red fumes when dissolving metals, I'm not sure what this is.

I haven't used nitric yet and would like to know as much as I can about it, before I use it someday.

 

[FrugalRefiner]

Only if it's fuming red or white. The 68 - 70% we usually use will not cause your hands to burst into flames.

Dave

Could someone go into more detail about this please? Unless you are talking about highly concentrated "fuming" Nitric giving off white fumes, or instead, red fumes when dissolving metals, I'm not sure what this is.

I haven't used nitric yet and would like to know as much as I can about it, before I use it someday.

I'm not a chemist, so I may be corrected, but most "concentrated" nitric acid is somewhere around 68 to 70%. That is the azeotrope for nitric acid, i.e., the point at which normal distillation at standard temperature and pressure will not make it any more concentrated. If you open a bottle of this, you will often see some white fumes coming off of it. If you pour some onto some silver or copper, you'll see some red fumes (NO_x) coming off of it. But it's still just "concentrated" nitric acid.

Nitric acid can be made more concentrated in ways I will not describe here. It involves removing more of the water than would be possible through normal distillation. When you get down to just a couple percent water, you have what is known as red fuming nitric acid (RFNA). It's a good rocket propellant, but it has no use in recovery and refining. It increases the flammability of just about everything, hence the impressive youtube videos of nitrile gloves bursting into flames.

White fuming nitric acid (WFNA) is an even more "concentrated" form, where the "break down" components of RFNA are minimized.

Again, I'm not a chemist, so that may not be an accurate representation, but in principle, what we work with in refining is not red fuming or white fuming nitric acid, even though it may give off red or white fume. It will not cause your gloves to burst into flames.

Dave

 

[jason_recliner]

So I take it then that red fuming nitric acid releases the same NO2 fumes that 50:50 diluted nitric does when used in AR.

:idea: :idea: :idea:
I also do not use nitric acid yet. When I do find it, or make it from the sufuric I also can't get, it will be quite expensive for me one way or another.

So if one were to collect these reaction fumes and scrub them through water, a certain amount of the NO2 could be recycled as dilute nitric acid or nitrous acid. On the off chance I understand this, peroxide would help it become more nitric than nitrous?

Edit: Sorry for the hijack. This is getting off topic.

 

[solar_plasma]

4metals

to determine diameter of a perfect sphere, but little else.

Plattners method doesn't measure any perfect shape, the flattening of the shape versus weight is found empircally. Otherwise it would not be any advantage to just measure the diameter by other means. Surely it cannot be compared to any expensive modern lab weight, I am pretty sure it is as good as or better than anything under 100 or 200 - given the assayer did a good job purifying his bead.

If it wouldn't be exact enough, those professionals in 1830 would have use larger probes like 1g instead of 100mg of ore. Anything else would not make sense. Soft science approach, my home terrain 8) :lol: Not save, but very probable.

Though, I have only one source I can't be sure, if the numbers are correct, even the method as such should be original.

 

[Topher_osAUrus]

So I take it then that red fuming nitric acid releases the same NO2 fumes that 50:50 diluted nitric does when used in AR.

:idea: :idea: :idea:
I also do not use nitric acid yet. When I do find it, or make it from the sufuric I also can't get, it will be quite expensive for me one way or another.

So if one were to collect these reaction fumes and scrub them through water, a certain amount of the NO2 could be recycled as dilute nitric acid or nitrous acid. On the off chance I understand this, peroxide would help it become more nitric than nitrous?

Edit: Sorry for the hijack. This is getting off topic.

Wfna and rfna are both above the azeotrope of 68%, which you dont need to worry about making unless you distill your azeotrope nitric again..

*i believe* that white is msde under vacuum, with absence of light, red is just red (again, i think..) because of the excess NO2 coloring the acid. On another forum, i read that if your distilled nitric is brownish (more than just a little yellow) keeping it out of direct light for a day or 2 will in turn, allow the unwanted gas to escape and clarify the HNO3.. Its been awhile since ive read that, so i will try to find it again and relay the pertinent information and the link

 

[FrugalRefiner]

Wfna and rfna are both above the azeotrope of 68%, which you dont need to worry about making unless you distill your azeotrope nitric again.

It doesn't matter how many times you distill it, it will not go higher than the azeotrope. That's essentially the definition of azeotrope - a mixture whose proportions cannot be altered by simple distillation.

Dave

 

[Topher_osAUrus]

Wfna and rfna are both above the azeotrope of 68%, which you dont need to worry about making unless you distill your azeotrope nitric again.

It doesn't matter how many times you distill it, it will not go higher than the azeotrope. That's essentially the definition of azeotrope - a mixture whose proportions cannot be altered by simple distillation.

Dave

http://www.science
That is where i resd of the double distill (if you are msking it from scratch) and also
http//oooo
On page 2 or 3 of that one it talks about it as well.
It just needs something very hygroscopic to break the azeotrope's 30%(ish) water.

If this is false information, i would surely like to know. So i can remove them from my notes/bookmarks.
Discussion of making reagents for, or of making explosives, is breaking the forum rules.
Fuming nitric acid is not only dangerous, but has no use in recovery or refining.
I disabled the links. Do not post links to places which discuss making explosives.
Butcher

-topher

 

[FrugalRefiner]

Wfna and rfna are both above the azeotrope of 68%, which you dont need to worry about making unless you distill your azeotrope nitric again.

It doesn't matter how many times you distill it, it will not go higher than the azeotrope. That's essentially the definition of azeotrope - a mixture whose proportions cannot be altered by simple distillation.

Dave

http://www.science
That is where i resd of the double distill (if you are msking it from scratch) and also
http://ooooooo
On page 2 or 3 of that one it talks about it as well.
It just needs something very hygroscopic to break the azeotrope's 30%(ish) water.

If this is false information, i would surely like to know. So i can remove them from my notes/bookmarks.

-topher

We're talking about two different things. Note that in my definition, I say "cannot be altered by simple distillation". That means simply taking the distillate and redistilling it. When you make nitric, the first distillation will produce something less than the azeotropic level. Repeated distillation will continue to concentrate the distillate toward the azeotrope.

The method described on the science madness thread involves adding sulfuric acid to nitric acid that is already near the azeotrope. That is no longer simple distillation of nitric acid. It's not false information, but it's not simple distillation. I didn't follow the other link far enough to find their process.

There is no need for fuming acids in what we do, and they are unnecessarily dangerous, so we don't encourage anyone to make them.

Dave

 

[Topher_osAUrus]

Ah Dave, i am totally with you now.

Sorry for the miscommunication. For i overlooked thr word "simple" in there.

Thanks for the clarity

 

[jason_recliner]

In my case, I was wondering about recovering the nasties escaping from AR and recycling them for cost reasons.
I can see now how that might also be pushing "making reagents" boundaries, so I apologise.

 

[butcher]

jason_recliner,
I do not see anything you should be apologizing for.

Recovering gases from a solution of nitric acid and metals where NOx gases are formed, or where these solutions or nitrate metal salts are heated, where HCl is not used.
Will be different than recycling gasses from aqua regia, or heating a solution, or nitrate and chloride mixture of salts, where we have gases of both acids.

NO_x gases can be recovered to form nitric acid, Nitric oxide (NO) gas is basically insoluble in water, and will need oxygen to convert it to the soluble nitrogen dioxide (NO2) gas, this reaction can be done different ways, using H2O2 with water in your receiving flask you are bubbling the gases through (inefficient), or by mixing oxygen in a spray mist of water in scrubbing system where the gases are held long enough to make a complete conversion much more contact time and more efficient...

With aqua regia, or heating of a mixture of nitrate and chloride salts, we would have both HCl and NOx gases, although HCl is more volatile than HNO3 and will distill off (pretty much) first. But there really is not that much separations of the gases so this is not a good method of separation.

In instances where you may only have a tiny bit of HCl (contamination) in nitric acid.
Discarding the first portion of the run (mostly HCl) from the distillation process can be somewhat helpful. Any little remaining HCl contamination in the nitric acid, can be removed with the use of silver nitrate additions to remove the HCl, as an insoluble silver chloride precipitant.




Remembering aqua regia is active as soon as it is mixed, where the volatile gases of nitrosyl chloride and chlorine are formed, which are the primary reason it oxidizes gold, or dissolves gold.

These gases will not stay in a stored container, and if the container is closed the pressure build up will burst the container.
We do not premix aqua regia and use it later. Storing it in a closed container is foolish and dangerous.

You can recycle some of the aqua regia by collecting gases from a heated vessel of aqua regia. If making gold chloride from dissolving gold in aqua regia.

You will have to remember some of the chlorides are left behind as gold chloride, so you may need to add some reagent HCl to the newly formed batch. (some of the nitric will also be lost, or converted to other gases)...

Also this newly formed batch of aqua regia, would have to be reused to dissolve more gold, fairly soon after it is formed.
Before it loses its effective gases. Or its effectiveness. Basically you cannot store it. or use it later to dissolve gold. although it would still be a strong acid.

 

[jason_recliner]

Thank you Butcher, for your kind reply.
As usual, I'm going to have to read it several times to take it all in. Some is second nature, some is "hmm, ok", and some means heavy duty study.
It was just an idea, and is probably further from my skillset than I thought.

 

[Topher_osAUrus]

...using H2O2 with water in your receiving flask you are bubbling the gases through (inefficient), or by mixing oxygen in a spray mist of water in scrubbing system where the gases are held long enough to make a complete conversion much more contact time and more efficient...

Thread hijack, (..again. ...sorry)

Reading the spray mist comment gave me an idea butcher. I attached a picture of whats going on in my mind, for both of the ideas that your comment spawned. Would these be feasible? Applicable?

Should i start a new thread for this?

Sorry about the.chicken scratch and cruddy drawing, i was in a rush. Before i was given this idea by you, i was going to start putting pieces of polypropylene in my H2O/H2O2 mix to keep the gasses bubbling in there longer for more time to convert

 

[solar_plasma]

Which cheap pump would resist the acid?

I have not tried it, but I imagine, it would make more sense to use an aquarium air stone for the gasses, which I would send with a slight overpressure generated by an aquarium air pump through the system. Further I would agitate the solution by a magnet stirrer in order to let the gas bubbles stay longer in contact with the water.

 

[Barren Realms 007]

Which cheap pump would resist the acid?

I have not tried it, but I imagine, it would make more sense to use an aquarium air stone for the gasses, which I would send with a slight overpressure generated by an aquarium air pump through the system. Further I would agitate the solution by a magnet stirrer in order to let the gas bubbles stay longer in contact with the water.

If you mean vacuum pump you can look on ebay and find and HVAC vacuum pump to use that seem to hold up fairly well. I use my freon recovery system pump for a couple of years and it never damaged the system from what I can tell and it still runs fine. Just change the oil on a regular basis.

 

[Anonymous]

Funny you should say that frank. I use an HVAC too and change the oil every weekend. Much better than the expensive Cole Palmer diaphram pump I had.

 

[Topher_osAUrus]

The aquarium pump im going to try to use to circulate H2O and peroxide will probably only survive one still session (5$...thats worthy of using it as a dispensible test to see if this idea holds water [no pun intended])

The vac pump i use is...well, its my wifes old breast pump she used when working snd rearing our two kiddos.. So far, its lasted through a dozen distill sessions....so, thats a win.

 

[upcyclist]

She knows not to use it if you have more kids, right?