Sciencemadness Discussion Board

Salt amoniac sublimation, best method???

pneumatician - 13-5-2021 at 17:46

A good manner of salt amoniac purification is by SUBLIMATION.

I want to sublimate 2-3 oz so what is the best method?

two reactors or around 2-3 liters mouth by mouth with cold clotes around???

a big funnel with cotton in the lower mouth?

...

TIA

hissingnoise - 14-5-2021 at 02:26

Small quantities are easily sublimed (note spelling) ─ collect the sublimate on a large inverted funnel sitting on the dish.

Forced cooling isn't required for a few ounces...


RustyShackleford - 14-5-2021 at 04:37

Its not a sublimation, you are forming two separate gases that re-react to form NH4Cl.
NH4Cl(s) -> NH3(g) + HCl(g) -> NH4Cl(s)
I have had good success with using an apparatus like this for cleaning moderate quantities of NH4Cl.

sublimating.png - 31kB

[Edited on 14-5-2021 by RustyShackleford]

[Edited on 14-5-2021 by RustyShackleford]

njl - 14-5-2021 at 04:44


Quote:

NH3(g) + Cl(g)


Should be NH3 + HCl

pneumatician - 14-5-2021 at 10:03

and 2 or 3 oz do not fall?

njl - 14-5-2021 at 10:05

If it falls it will land on the watchglass!

pneumatician - 23-5-2021 at 02:23

how are these items used? no videos in ytb...

https://www.ebay.de/itm/162646980969?ssPageName=STRK%3AMEBID...

Fyndium - 23-5-2021 at 02:31

Fill with substrate, put circulant water through condenser, apply vacuum and heat. Collect sublimate. Repeat.

Beaker with flask and watchglass seems to be a great solution, and the size can be increased probably up to 10L beaker/flask if enough heating power is available.

I could imagine that industry uses horizonal vacuum vessels that can be constantly fed and extracted with substrate, and the have condensers with mechanical scrapes that constantly sublime and then scrape the sublimate to fall off into an auger for takeoff. The heated reserve likely has a bottom auger to extract the impurities left behind.

pneumatician - 23-5-2021 at 08:46

Quote: Originally posted by Fyndium  
Fill with substrate, put circulant water through condenser, apply vacuum and heat. Collect sublimate. Repeat.


ok you need to control the vacuum force and the fire because too much fire = too much sublimation and the sublimate go to vacuum tube?

if so I see no advantage in it...

maybe the best is a tube like a washing bottle with the opening in the base... or a large tube...

the pic is very bad! :-)

Fyndium - 25-5-2021 at 22:16

Vacuum can be very hard to control, heat not so. I see no issue here.