Siphoning boiling nitric using a pump.

[uetz2]

As to why it needs to be boiling is concerning and I was uninformed about the faults of PTFE. I guess I need to do more research on tubing.

Randolph manufacturers a new cilran tubing for strong acids that handles up to 190 degree F

 

[4metals]

Randolph manufacturers a new cilran tubing for strong acids that handles up to 190 degree F

Thank you for that! The fix that seems to work best for the OP is suction through tubing into glassware using a good strong vacuum. Drawing acid through tubing with vacuum is less hazardous as any splits or pin holes will draw air into the hose rather than squirting acid out.

Welcome to the forum.

Edited replaced the word it with acid for clarity.

 

[uetz2]

Sorry posted twice. Not very good at this

I guess the water induction for vacuum would trap a lot of fumes also. I'm adverse to nitric fumes.

 

[4metals]

I guess the water induction for vacuum would trap a lot of fumes also. I'm adverse to nitric fumes.

The venturi vacuum generators I use have a recirculating water reservoir. It does build up fumes, both NOx as you noted, and Sulfur Dioxide from dropping gold. So it is vented into a feed line into the fume scrubber. Because you are correct, it does stink!

 

[Yggdrasil]

The venturi vacuum generators I use have a recirculating water reservoir. It does build up fumes, both NOx as you noted, and Sulfur Dioxide from dropping gold. So it is vented into a feed line into the fume scrubber. Because you are correct, it does stink!

Would a weak NaOH solution in the water reservoir help with this?

 

[4metals]

Would a weak NaOH solution in the water reservoir help with this?

It would but long term use will cause salt deposits that will clog the venturi nozzles. And the reservoir will develop a stink anyway so
permanent venting transfers any salt buildup to the fume scrubber where those build ups are monitored because you want to catch it before it clogs up.

 

[Amol Gupta]

I have used PTFE tubing to transfer concentrated nitric from a drum to an acid
reservoir with vacuum. But the acid is ambient temperature. Sharp bends in the tubing were the first to fail, albeit after a few years of service. I cannot imagine what the kneading of the tube would do to it.

As far as the OP saying boiling nitric acid, I assume it was because the acid parting of the Silver is done with hot acid and he didn’t want to wait for it to cool.

Is there a way to determine the health(physical condition) of the tubing, signs of possible future leaks, something like preventive maintenance to minimize possible leaks.

 

[grainsofgold]

let the nitric cool then use a magnetic drive self priming pump that is acid resistant. pricey but you can use it for other things as well. As 4 metals stated the hot acid is hard on a pump and was also told by a pump supplier.

 

[Amol Gupta]

let the nitric cool then use a magnetic drive self priming pump that is acid resistant. pricey but you can use it for other things as well. As 4 metals stated the hot acid is hard on a pump and was also told by a pump supplier.

An aspirator pump is what I have resolved to.