Does copper only knock out gold or does it also knock out silver?

[lazersteve]

Erlenmeyer flask are not recommended for digestion as the tapered neck is subject to cause over flows when the reaction kicks up and foams. Straight walled containers with cover in a catch basin are the recommended way to perform digestions.

Steve

 

[Yggdrasil]

I assumed a beaker is used.
The flasks need to be able to withstand a bit of vacuum, but not too bad since it is an open system.
But they need to have stopper allowing two lines in/out.

 

[beatmopzz]

I wanted to neutralize the nitric acid with sodium carbonate, but it didn't work out, so I cemented it with copper, and I think that's why there was iron hydroxide on top. What do you think? Why does silver not dissolve in AR?

 

[Yggdrasil]

I wanted to neutralize the nitric acid with sodium carbonate, but it didn't work out, so I cemented it with copper, and I think that's why there was iron hydroxide on top. What do you think? Why does silver not dissolve in AR?

This post make no sense.
Describe your situation more in detail.
AR will not dissolve Silver because any Chlorine in a solution will form Silver Chloride which is not soluble in acids.
Next, we do not want to neutralize Nitric normally, so why do you want to do so?

Finally do some more studying.

We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum:
https://goldrefiningforum.com/phpBB3/viewtopic.php?f=54&t=197982. Then read the safety section of the forum
3. And then read about "Dealing with waste" in the forum

 

[ólom]

What kind of nitric acid does palladium dissolve in, dilute concentrated or both? I read the book but I don't remember it, now I started reading it again.

 

[Yggdrasil]

A google search gave this result:
Palladium, particularly if alloyed with gold or silver, dissolves in dilute nitric acid.
Fine grained palladium is soluble in concentrated nitric acid, concentrated hydrochloric acid or aqua regia.

 

[ólom]

A google search gave this result:
Palladium, particularly if alloyed with gold or silver, dissolves in dilute nitric acid.
Fine grained palladium is soluble in concentrated nitric acid, concentrated hydrochloric acid or aqua regia.

Thank you very much for looking!

 

[ólom]

Here is a sketch
View attachment 55314

I got a bunch of 10.5 centimeter diameter pvc pipes for free. Will that be good for the scrubber?

 

[Yggdrasil]

I got a bunch of 10.5 centimeter diameter pvc pipes for free. Will that be good for the scrubber?

I think that will be a bit small.
It depends on the length and volume of gas that is passing through.
But for the NOx scrubber I posted in the sketch, the scrubbing is done in the bottles.
It works best with as small bubbles as possible and they need about 9 seconds of contact with a wetted surface.

 

[ólom]

I think that will be a bit small.
It depends on the length and volume of gas that is passing through.
But for the NOx scrubber I posted in the sketch, the scrubbing is done in the bottles.
It works best with as small bubbles as possible and they need about 9 seconds of contact with a wetted surface.

Thanks for the answer

 

[ólom]

I think that will be a bit small.
It depends on the length and volume of gas that is passing through.
But for the NOx scrubber I posted in the sketch, the scrubbing is done in the bottles.
It works best with as small bubbles as possible and they need about 9 seconds of contact with a wetted surface.

I think that will be a bit small.
It depends on the length and volume of gas that is passing through.
But for the NOx scrubber I posted in the sketch, the scrubbing is done in the bottles.
It works best with as small bubbles as possible and they need about 9 seconds of contact with a wetted surface.

How should it be done so that it is in contact with the moistened surface for 9 seconds and how should it be done so that there are as few gas bubbles as possible?

 

[Yggdrasil]

How should it be done so that it is in contact with the moistened surface for 9 seconds and how should it be done so that there are as few gas bubbles as possible?

I made you a sketch, you can add as many bottles as needed.

 

[ólom]

I made you a sketch, you can add as many bottles as needed.

Thanks for the answer!

 

[ólom]

I did the washer, but I couldn't put the vacuum pump on because of the lack of parts. Do you think it will be good?

 

[Yggdrasil]

I did the washer, but I couldn't put the vacuum pump on because of the lack of parts. Do you think it will be good?

I think you have misunderstood.
This setup have to have vacuum and thick walled bottles to handle the vacuum.

You use an ordinary 1-4 liter Borosilicate beaker, have a funnel upside down on this beaker.
From the bottom of this beaker you have a hose into a thick walled bottle/flask with a tight stopper/cap.
This cap has two holes that is gas tight around the tubing.
The tubing from the funnel goes to the bottom of this bottle and the other tubing is outside the liquid to lead the gas into the next bottle.
In this bottle you have a mix of water and Hydrogen peroxide to take up the NOx fumes and scrub the fumes.
You can also have some filler so the gas uses longer time to bubble to the surface.
This can be repeated until the gas is clean, but I guess one to two bottles is enough.
Then after this you can put in a bottle with dilute NaOH to neutralize the rest gases/fumes.
The important thing is to have a empty bottle in the end to collect what ever liquid drags over.
This can be dropped if you have the NaOH bottle and use an eductor for Vacuum.

As you see, you can actually recover some of the fumes as dilute Nitric or just plain scrub it for waste.
That is up to the user.

 

[ólom]

I spelled it wrong. I haven't connected the vacuum pump to it yet.

 

[KalleMP]

This is the chart Yggdrasil is referring too. as he mentioned copper will cement or react with metals below itself while those above will cement copper.

Take a look at iron, yes iron will cement all those metals below itself in the electromotive series.

Sorry to probe an old comment:

I recall Hydrogen is used as a reference electrode when determining the electrode potentials but a though just occurred to me.

What happens if we were to bubble generous amounts of Hydrogen through a AR solution containing gold or a Copper nitrate solution?

Is the use of Hydrogen to precipitate a thing?

Are we left with Nitric acid?

 

[ólom]

I think you have misunderstood.
This setup have to have vacuum and thick walled bottles to handle the vacuum.

You use an ordinary 1-4 liter Borosilicate beaker, have a funnel upside down on this beaker.
From the bottom of this beaker you have a hose into a thick walled bottle/flask with a tight stopper/cap.
This cap has two holes that is gas tight around the tubing.
The tubing from the funnel goes to the bottom of this bottle and the other tubing is outside the liquid to lead the gas into the next bottle.
In this bottle you have a mix of water and Hydrogen peroxide to take up the NOx fumes and scrub the fumes.
You can also have some filler so the gas uses longer time to bubble to the surface.
This can be repeated until the gas is clean, but I guess one to two bottles is enough.
Then after this you can put in a bottle with dilute NaOH to neutralize the rest gases/fumes.
The important thing is to have a empty bottle in the end to collect what ever liquid drags over.
This can be dropped if you have the NaOH bottle and use an eductor for Vacuum.

As you see, you can actually recover some of the fumes as dilute Nitric or just plain scrub it for waste.
That is up to the user.

I did as you just described, but I didn't use a beaker.

 

[Yggdrasil]

I did as you just described, but I didn't use a beaker.

No, look again and check.
You made something completely different.
It may look a bit similar but its, not.
None of your bottles has a cap and they are not air-tight.
They will not hold up any vacuum.

You seems to have built a kind of fume hood like contraption.
The design I made a sketch of is to bypass the need for a full fledged fume hood when doing AR leaches.
It is usually held in a fume hood itself.

 

[ólom]

No, look again and check.
You made something completely different.
It may look a bit similar but its, not.
None of your bottles has a cap and they are not air-tight.
They will not hold up any vacuum.

You seems to have built a kind of fume hood like contraption.
The design I made a sketch of is to bypass the need for a full fledged fume hood when doing AR leaches.
It is usually held in a fume hood itself.

Thanks for the answer!