mesanaw - 29-10-2016 at 07:45
I am trying to extract bismuth from Pepto Bismo using the HCL and aluminum procedure, but I ended up with a pile of bismuth powder mixed in with
aluminum. The aluminum pieces are too small and brittle to manually remove and I think around 40% of the powder is aluminum.
Does anyone have any suggestions on how to separate the two metals so that I end up with mostly bismuth?
Thanks.
Jstuyfzand - 29-10-2016 at 07:57
Maybe Sodium Hydroxide to dissolve the Al?
I dont know what it will do to the bismuth though
pinkamena - 29-10-2016 at 09:15
You could just throw the whole mixture into hydrochloric acid, aluminium will dissolve because it's electropotential is below that of hydrogen (Al3+ +
3e- > Al : -1.7V), and bismuth will remain because it's electropotential is above that of hydrogen (Bi3+ + 3e- > Bi : +0.4V).
mayko - 29-10-2016 at 09:49
Did you shred the aluminum? I've seen some preps do this but I've precipitated bismuth just fine with an aluminum foil sheet corrugated into a fan,
with minimal aluminum contamination
mesanaw - 29-10-2016 at 12:02
I just stirred the solution with a large piece of aluminum and then let it rest in the container. I'm going to try washing it with dilute HCL and
hopefully that will work.
It worked perfectly. I have some really clean-looking powder thanks everyone!
[Edited on 29-10-2016 by mesanaw]
MrHomeScientist - 31-10-2016 at 06:30
The real trick is turning that powder into a solid ingot of metal! Because of its high surface area, it oxidizes to yellow bismuth(III) oxide instead
of melting when heated. I tried a few tricks to get it to melt but never could. Now that I have an argon cylinder, it might be worth looking into
again.
elementcollector1 - 31-10-2016 at 07:39
I managed to do it with cadmium powder and copious amounts of NaOH flux, so it should be possible.
Deathunter88 - 31-10-2016 at 10:44
Here is a video of Nile Red getting bismuth metal into an ingot from powder that he extracted from pills. He says that strong heating of the bismuth
oxide will decompose it back into bismuth metal and oxygen.
https://www.youtube.com/watch?v=grpSfjUImUs