oxygen in AP

[Geo]

i have in my possession a working oxygen concentrator that is used for medical purposes. the operating range is 6 lpm at about 8 psi at 50' of hose.it was in good working order when i received it and the catalyst was fairly new.the question is would there be any danger in adding pure oxygen to my AP solution using a glass bubbler? im already using the air supply from a medical nebulizer atomizer pump and it blast the air to it,i could add a T just after the air pump and add the oxygen hose.i understand the reaction is only limited to the oxygen available so this should speed the process up by a matter of days as long as its safe to do so.

 

[butcher]

The only thing I can think of where there may be a problem is where you do not want to dissolve the gold and only want to dissolve the copper like in the acid peroxide method,

But would be very useful to rejuvenate your copper chloride between use, like making copper I chloride solution into copper II chloride solution, or using in solution to dissolve gold or maybe pumping into an incineration to convert carbonous materials to CO2 gas, or to help oxidize the metals, or when adding oxygen to your fuel like in a torch to get a hotter melt.

edit to add this thought: adding oxygen to your NO2 gas bubbling into water from distilling (nitrates) to make nitric acid in solution.

 

[Geo]

great.thanks for the tips.

 

[Shaul]

At my workplace we service them, and so there's a constant supply.
I remember asking Lazersteve (several years ago) this very same question.
I do remember that his response was Negative, though I can't remember why.

On another side, I'm wondering about the possibility of coupling the output of an oxygen concentrator with a propane torch to create an oxy-propane.

Shaul

 

[samuel-a]

But would be very useful to rejuvenate your copper chloride between use, like making copper I chloride solution into copper II chloride solution,

Just a side note addition.
There's a limit to rejuvenation of AP (copper chloride actually) without adding HCl. It is very much depends on free HCl in the solution. Even the black saturated AP solution still holds some free HCl and the air pumped in helps oxidizing some Cu(I) to Cu(II):

4 HCl + O₂ = 2 Cl₂ + 2 H₂O ===>
2 CuCl + Cl₂ = 2 CuCl₂

I could only expect that rich O2 air pumped in will make rejuvenation faster.
Any gold that will dissolve, will quickly be cemented in a saturated AP as fine black powder.

 

[butcher]

Years ago I had a small torch that used the small oxygen and propane cylinders, the torch was a very simple torch handle and tip was something similar to the welding torch on my oxygen and acetylene rig only much smaller.

but you could possibly find one of these torch handle and tip with the two rubber hoses and use that with propane (regulated)and your oxygen generator, they use a small amount of oxygen (I do not expect a breathing oxygen generator puts out large volumes of oxygen), maybe at the second hand stores. Or if you are handy build your own easily.

I also had one of this small torch’s that used carbide and water to make acetylene, and I think magnesium oxide? Or some kind of oxidizing chemical and water to make the oxygen, the hoses and torch handle and tip were also very small and simple.

Furnace burners are very easy to make out of common plumbing pipe, these can be made in many different sizes and types, and you can even make one to run in a handheld fashion like a torch, adding your oxygen (possibly even mixed with any air needed) would be very simple.

 

[element47]

"On another side, I'm wondering about the possibility of coupling the output of an oxygen concentrator with a propane torch to create an oxy-propane."

On my first read, I find it a tad surprising that these medical concentrators (my Mom who has been bedridden got one) can supply the rate of flow required for an oxy-propane torch in the first place, BUT, I haven't done or checked or thought about the calcs. My point of reference is a bedside single-patient unit. Obviously we are not talking about using the cutting function of an oxy-propane torch, because that would pretty obviously require more oxygen than such a thing could supply. (eg, no cutting, just heating with our oxy-Prop torch)

But from another aspect, I think you could create and have purity issues using the "oxygen" from such a unit to fuel an oxy-propane torch. When you get a tank of oxygen from your welding supplier....there are several grades; medical and breathing oxygen are really pure but even welding oxygen is quite pure. Of course, I am using the word "pure" on a forum where .999 purity is an everyday topic.

I would want to know the proportional gas composition coming out of one of those oxygen concentrators. I seriously doubt those things remove ALL the nitrogen. I'd be quite surprised if they removed the majority of the nitrogen. IMHO having excess nitrogen in a melting flame would be an invitation to "something", probably not good. I've never tried it so maybe I'm completely wrong. Yes, nitrogen is fairly inert, but when you have it heated up in a near-plasma state with other metals, also in well over a red-hot state, you are going to get reactions and/or uptake into your liquid metals. And frankly, store-bought oxygen is pretty cheap compared to most of the other goodies needed to refine.

What I am struggling to say is: IF there is a problem you could engeneder or create having too much nitrogen in a torch, you'll undoubtedly have this problem using such a concentrator for your "oxygen".

 

[samuel-a]

element47

As far as i know of, those concentrators put out somewhere around 92-96% O2.


p.s.- i wouldn't worry about producing any plasma in my melting dish... the conditions just not there...
Though you did intrigued my interest to take look at the "primordial soup" theory once again... :mrgreen:

 

[butcher]

normal atmospheric air is about 78% nitrogen and about 21% oxygen.

When we combust fuel like propane, gasoline, diesel, coal, wood, and so on, these contain carbon and hydrogen in differing ratio's

Propane (C3H8) has 3 carbons and 8 hydrogen’s.

When we combust this fuel we need heat, oxygen and fuel (carbon) to burn without any one of these our burner won’t fire.

Incomplete combustion produces (CO) carbon monoxide, lack of air or oxygen, we usually prefer an excess of air or oxygen to complete combustion thus producing CO2 gas.

Also with torches depending on what we are doing we may want a reducing flame or an oxidizing flame these will actually change the chemistry of our metals in the melting process.

Carbon from fuel (propane C3H8) burns the hydrogen does not burn.

In our air 21%oxygen and 78% nitrogen, the oxygen burns the nitrogen does not.

So for propane we have in our combustion C3H8 +5O2 --> 3CO2g + 4H20.

Notice the carbon and oxygen produce CO2 gas.

The Hydrogen and oxygen produce water vapor.

(What about the nitrogen in our air?).

Well it produces NOx gases< industrially or in our vehicles we have ways to deal with these but that is another story.

Nitrogen normally will not give us problems in our propane burners or torches as long as we have the oxygen to burn the carbon .

Medical oxygen is usually given many times mixed with nitrogen, or medical air, or sometime room air around the patient, in the hospital as breathing pure oxygen from what I understand is not healthy and may burn the lungs( I am no doctor and really cannot say my fact here is stated proper).

I really do not know how pure prescription medical oxygen is in the tanks, or how pure the welding oxygen is? For all I know they may come from the same source, and contamination of tanks may be an issue, we sure would not want to breathe air from some welder’s tank no telling where it has been, then again there may be some minor difference.

The way I understand these portable unit oxygen generators is they use a catalyst of some type, I presume they just increase the oxygen content of the air exiting them, probably not pure oxygen, (this would improve combustion and heat in our torch or burner.

Fuel and air (oxygen) need to be mixed in certain proportions for complete combustion (usually some excess air (15%)to get the oxygen content needed) other wise we have incomplete combustion of the carbon (reducing flame) and produce more dangerous gases carbon monoxide.

Some fuels also contain sulfur (diesel, coal) and getting complete combustion and flue stack temperatures higher is important with them again another story.

 

[samuel-a]

The way I understand these portable unit oxygen generators is they use a catalyst of some type,

Butcher

In case you are interested:
Molecular sieve bed

Very well explained i must add, kudos to you butcher.

 

[niteliteone]

From what i have seen they use a cartridge like a reverse osmosis water filter. except it only passes the nitrogen we don't use leaving the oxygen in the air flow to the hose.

Or something like that. :shock:

Tom C.

edit:
My bad. My description was for a nitrogen generator as at:
http://en.wikipedia.org/wiki/Nitrogen_separation_membrane#Membrane_technology

Though the waste output is very concentrated oxygen. :shock:

 

[butcher]

Thanks will read when I get chance, have not read this but bet it will also help.

http://en.wikipedia.org/wiki/Oxygen_concentrator

 

[Geo]

im not a technician and don't know the chemistry behind it but i have dismantled many of these units and the catalyst uses the moisture from the air to produce the extra oxygen.it doesn't really concentrate whats there as much as it adds to what is there.the beads inside the reaction tank(s) react violently when introduced to water.the gases produced is not flammable or explosive (if it were i wouldn't be here).ok,furthering the thread.i did a small experiment today with the unit i have.i placed 100 grams of clean pins in a coffee pot and added 200 ml muriatic acid and 200 ml loaded AP solution.i placed a hose from the concentrator in the pot after attaching a small blue bubble stone (this stone is one ive had for two months and has been through several AP batches).i placed the pot on a hot plate and heated to just warm to the touch.after four hours the pins were digested and wanting to see how far i could push it i added another 100 grams of pins.after six hours everything seemed to be digested but i really couldnt tell as the solution was very black.i removed the stone and turned off the heat to allow it to cool so i could filter the solution.heres the reason adding oxygen to AP is not good.after the solution cooled i set up the filter and the solution had changed to a semi-solid.i had made copper pudding.im sure that the addition of fresh hcl will dilute this back to a liquid so tomorrow ill see what damage was done and if i can find gold in this mess.ill post a few pics if theres anything worth showing.

 

[niteliteone]

Geo,
LMAO,
I thought I was the only one to get these kinds of results.

Thanks, You made my night.
Tom C.

 

[Harold_V]

after the solution cooled i set up the filter and the solution had changed to a semi-solid.i had made copper pudding.

Did you entertain the idea of diluting the solution somewhat?

Ever see a couple liters of silver nitrate solution convert to silver nitrate crystals? It happens very quickly, right before your eyes, as the solution cools. All that is required to prevent crystal formation is to dilute. Another liter of water solved the riddle, if memory serves.

Harold

 

[Barren Realms 007]

after the solution cooled i set up the filter and the solution had changed to a semi-solid.i had made copper pudding.

Did you entertain the idea of diluting the solution somewhat?

Ever see a couple liters of silver nitrate solution convert to silver nitrate crystals? It happens very quickly, right before your eyes, as the solution cools. All that is required to prevent crystal formation is to dilute. Another liter of water solved the riddle, if memory serves.

Harold

You can reconvert the crystals back to solution with a less percentage of water.

 

[Geo]

thanks for the tip.i couldn't measure the volume but i suppose it could have lost water to evaporation.its been on the cool side here.normally i tend to feel like adding water to AP is something to avoid but if your heating the solution and you don't add water it concentrates the solution.i wish i had read this before i went out this morning.i did add more muriatic acid and it did dilute back to a liquid but i had to reheat it.there was still a small amount of pins left undissolved so i left it on the heat without any air to finish dissolving these.just a thought but could the O2 bubbling through the solution make it lose water faster?

 

[butcher]

Adding the oxygen to the gold plated pin when using HCl with heat would dissolve the gold with the copper, (my opinion not good choice), by adding 3% peroxide we are not only diluting the copper chloride solution with water but we are also adding very small bubbles of oxygen to oxidize the copper, not enough oxidizer to dissolve the gold (our goal at least).

This to me is akin to using aqua regia, on gold and base metals to dissolve everything, (just complicating things), you can cement on copper, or since you have not dissolved all of the pins most of your gold may be with them.

Do not forget stannous chloride tests here.


Geo if we had just HCl twenty some odd percent, and heated it some of our Hcl would try and combine with copper oxide, but we would soon be vaporing off our HCl as gas (wasting our acid) and the HCl can only concentrate up to its azeotrope, just a little over what we have here before heat would just vapor off the acid, If heating HCl adding water is beneficial to keep our acid in the reaction doing what we want it to (not just making