Nitric Acid - cold temps

[ólom]

So what you say is that Ferric Chloride is faster than Cupric Chloride?

Yes

 

[ólom]

Szóval azt mondod, hogy a vas-klorid gyorsabb, mint a réz-klorid?

https://goldrefiningforum.com/threads/ferric-chloride-recovering.1474/

 

[Martijn]

So what you say is that Ferric Chloride is faster than Cupric Chloride?

From what i can find the copper etching rate of Ferric Chloride is 212nm/s @40C and Cupric Chloride is 465nm/s. (1.1mils/min)

Temperature increases the the rate.

And FeCl2 can be regenerated with HCl and oxygen. Not sure how fast that works.

 

[Yggdrasil]

From what i can find the copper etching rate of Ferric Chloride is 212nm/s @40C and Cupric Chloride is 465nm/s. (1.1mils/min)

Temperature increases the the rate.

And FeCl2 can be regenerated with HCl and oxygen. Not sure how fast that works.

Then you would need Iron, right?
Or will the amount available as Chloride suffice?

 

[Martijn]

So what you say is that Ferric Chloride is faster than Cupric Chloride?

Yes

From what i can find the copper etching rate of Ferric Chloride is 212nm/s @40C and Cupric Chloride is 465nm/s. (1.1mils/min)

Temperature increases the the rate.

And FeCl2 can be regenerated with HCl and oxygen. Not sure how fast that works.

Then you would need Iron, right?
Or will the amount available as Chloride suffice?

I responded to these posts; From what i've found, I seems Copper chloride is faster, but Olom thinks otherwise.
Regeneration by oxygen and HCl additions is comparable from what I can find in studies.
The HCL+ air/O2 way is said to be the cheapest way to regenerate.

 

[ólom]

From what i can find the copper etching rate of Ferric Chloride is 212nm/s @40C and Cupric Chloride is 465nm/s. (1.1mils/min)

Temperature increases the the rate.

And FeCl2 can be regenerated with HCl and oxygen. Not sure how fast that works.

Are you talking about FeCl2 or FeCl3? There are very old threads on the forum about FeCl3. You can search for it under the name iron chloride.

 

[Yggdrasil]

Are you talking about FeCl2 or FeCl3? There are very old threads on the forum about FeCl3. You can search for it under the name iron chloride.

Ferric Chloride is FeCl₃

 

[eprigge]

Regarding barrel heaters... there is a seller on eBay I just bought one from. They are in China, very cheap. They have many different varieties listed but they will do custom builds based on any specifications. They made a custom 50W, 10C built-in thermostat one for me that I will use on a 2G bucket that I'll be doing AP in outdoors. It will sit inside a 5G bucket with some insulation.

https://www.ebay.com/itm/146277056392

Hard to beat the price!

 

[Geber]

Would it be viable to digest silver with dilute nitric acid at room temperature in a closed vessel without a fume hood? Like you just set up the reaction and let it proceed slowly over weeks while you do other projects?

 

[Yggdrasil]

Would it be viable to digest silver with dilute nitric acid at room temperature in a closed vessel without a fume hood? Like you just set up the reaction and let it proceed slowly over weeks while you do other projects?

It can not be completely closed as there must be some room for the NOx gases.
So if you have a hose or something that vents into some water or similar it should be ok.

 

[Shark]

And that water can become a very weak nitric in the process.

 

[Geber]

It can not be completely closed as there must be some room for the NOx gases.
So if you have a hose or something that vents into some water or similar it should be ok.

I was hoping to do it in a closed vessel. I hoped that as the air gets filled with NOx, it reabsorbs into the water and forms nitric again, and that the pressure remains safe because of the slow kinetics. Do you know if it's been done this way? Also should I do the standared 2:1 water to 67% nitric?

 

[Yggdrasil]

I was hoping to do it in a closed vessel. I hoped that as the air gets filled with NOx, it reabsorbs into the water and forms nitric again, and that the pressure remains safe because of the slow kinetics. Do you know if it's been done this way? Also should I do the standared 2:1 water to 67% nitric?

The danger is that either presdure or vacuum build up.
Both may ruin your vessels.

 

[adam mizer]

Not all NOx will be absorbed back.
Also the speed of absorption is different for each variant of NOx.
This should never be done indoors without the proper features to be added.
Minimum a proven vapor system. If you do that then a scrubber system could be added and start adding/building fume hood system.
The whole thing about gasses inside is extremely dangerous.
And as Ygg states pressure or vacuum has to be considered.

 

[Geber]

Not all NOx will be absorbed back.
Also the speed of absorption is different for each variant of NOx.
This should never be done indoors without the proper features to be added.
Minimum a proven vapor system. If you do that then a scrubber system could be added and start adding/building fume hood system.
The whole thing about gasses inside is extremely dangerous.
And as Ygg states pressure or vacuum has to be considered.

I see. What do you mean by vapor system exactly?

Right now I have a fume hood and I digest my sterling inside it in an Erlenmeyer flask with a ground glass joint and three gas-washing bottles in series. I probably don't even need to use the fume hood's fan except when I relieve the vacuum as the vessel cools. The problem is it is only about 3 feet by 2 feet and I would like to have systems I can run passively and with no electric. Maybe some gas washing bottles connected to another flask.

I know with copper and nitric, the reaction can run away because it self-heats. Silver seems not to do this. Is that right?

 

[adam mizer]

I see. What do you mean by vapor system exactly?

Right now I have a fume hood and I digest my sterling inside it in an Erlenmeyer flask with a ground glass joint and three gas-washing bottles in series. I probably don't even need to use the fume hood's fan except when I relieve the vacuum as the vessel cools. The problem is it is only about 3 feet by 2 feet and I would like to have systems I can run passively and with no electric. Maybe some gas washing bottles connected to another flask.

I know with copper and nitric, the reaction can run away because it self-heats. Silver seems not to do this. Is that right?

Oh... vapor system. Someway to remove gas vapors from your work.
If you can, make a scrubber with it.
There are many posts about scrubbers, and hoods.
A recent one a month or 2 ago I was reading. 4metals and YGG helped the poster develop a hood and a scrubber system.

 

[Thomas M Joseph]

I know with copper and nitric, the reaction can run away because it self-heats. Silver seems not to do this. Is that right?

Although copper reacts more rapidly than silver, both reactions are exothermic and produce heat and toxic gas. Runaway reactions with silver can happen if not properly controlled.

 

[Yggdrasil]

I see. What do you mean by vapor system exactly?

Right now I have a fume hood and I digest my sterling inside it in an Erlenmeyer flask with a ground glass joint and three gas-washing bottles in series. I probably don't even need to use the fume hood's fan except when I relieve the vacuum as the vessel cools. The problem is it is only about 3 feet by 2 feet and I would like to have systems I can run passively and with no electric. Maybe some gas washing bottles connected to another flask.

I know with copper and nitric, the reaction can run away because it self-heats. Silver seems not to do this. Is that right?

If the metals are in the form of Solid chunks I do not believe they will react violently in cold dilute Nitric.
Even powders should be relatively safe in cold dilute conditions.